Search

Your search keyword '"C. Hoischen"' showing total 79 results
Start Over Author "C. Hoischen"
79 results on '"C. Hoischen"'

1. A MeerKAT, e-MERLIN, HESS, and Swift search for persistent and transient emission associated with three localized FRBs

Author

J O Chibueze, M Caleb, L Spitler, H Ashkar, F Schüssler, B W Stappers, C Venter, I Heywood, A M S Richards, D R A Williams, M Kramer, R Beswick, M C Bezuidenhout, R P Breton, L N Driessen, F Jankowski, E F Keane, M Malenta, M Mickaliger, V Morello, H Qiu, K Rajwade, S Sanidas, M Surnis, T W Scragg, C R H Walker, N Wrigley, H E S S Collaboration: F Aharonian, F Ait Benkhali, E O Angüner, M Backes, V Baghmanyan, V Barbosa Martins, R Batzofin, Y Becherini, D Berge, M Böttcher, C Boisson, J Bolmont, M de Bony de Lavergne, M Breuhaus, R Brose, F Brun, T Bulik, F Cangemi, S Caroff, S Casanova, J Catalano, M Cerruti, T Chand, A Chen, O U Chibueze, G Cotter, P Cristofari, J Damascene Mbarubucyeye, J Devin, A Djannati-Ataï, A Dmytriiev, K Egberts, J-P Ernenwein, A Fiasson, G Fichet de Clairfontaine, G Fontaine, S Funk, S Gabici, S Ghafourizadeh, G Giavitto, D Glawion, M-H Grondin, M Hörbe, C Hoischen, T L Holch, Zhiqiu Huang, M Jamrozy, F Jankowsky, V Joshi, I Jung-Richardt, E Kasai, K Katarzyński, U Katz, B Khélifi, W Kluźniak, Nu Komin, K Kosack, D Kostunin, A Lemière, J-P Lenain, F Leuschner, T Lohse, A Luashvili, I Lypova, J Mackey, D Malyshev, V Marandon, P Marchegiani, A Marcowith, G Martí-Devesa, R Marx, A Mitchell, R Moderski, L Mohrmann, E Moulin, J Muller, K Nakashima, M de Naurois, A Nayerhoda, J Niemiec, A Priyana Noel, P O’Brien, S Ohm, L Olivera-Nieto, E de Ona Wilhelmi, M Ostrowski, S Panny, R D Parsons, S Pita, V Poireau, D A Prokhorov, H Prokoph, G Pühlhofer, A Quirrenbach, P Reichherzer, A Reimer, O Reimer, G Rowell, B Rudak, E Ruiz-Velasco, V Sahakian, S Sailer, H Salzmann, D A Sanchez, A Santangelo, M Sasaki, H M Schutte, U Schwanke, J N S Shapopi, A Specovius, S Spencer, R Steenkamp, S Steinmassl, T Takahashi, T Tanaka, C Thorpe-Morgan, N Tsuji, C van Eldik, J Veh, J Vink, S J Wagner, A Wierzcholska, Yu Wun Wong, A Yusafzai, M Zacharias, D Zargaryan, A A Zdziarski, A Zech, S J Zhu, S Zouari, N Żywucka, High Energy Astrophys. & Astropart. Phys (API, FNWI), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux (UB), Laboratoire Univers et Particules de Montpellier (LUPM), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)

Subjects
radio continuum: galaxies, High Energy Astrophysical Phenomena (astro-ph.HE), ) fast radio burst [(transients], FOS: Physical sciences, Astronomy and Astrophysics, radiation mechanisms: non-thermal, non-thermal [radiation mechanisms], Astrophysics - Astrophysics of Galaxies, galaxies [radio continuum], fast radio bursts, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), (transients:) fast radio burst, ddc:520, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Monthly notices of the Royal Astronomical Society 515(1), 1365 - 1379 (2022). doi:10.1093/mnras/stac1601, We report on a search for persistent radio emission from the one-off fast radio burst (FRB) 20190714A, as well as from two repeating FRBs, 20190711A and 20171019A, using the MeerKAT radio telescope. For FRB 20171019A, we also conducted simultaneous observations with the High-Energy Stereoscopic System (H.E.S.S.) in very high-energy gamma rays and searched for signals in the ultraviolet, optical, and X-ray bands. For this FRB, we obtain a UV flux upper limit of |$1.39 \times 10^{-16}~{\rm erg\, cm^{-2}\, s^{-1}}$|Å^−1, X-ray limit of |$\sim 6.6 \times 10^{-14}~{\rm erg\, cm^{-2}\, s^{-1}}$| and a limit on the very high energy gamma-ray flux |$\Phi (E\gt 120\, {\rm GeV}) \lt 1.7\times 10^{-12}\, \mathrm{erg\, cm^{-2}\, s^{-1}}$|⁠. We obtain a radio upper limit of ∼15 |$\mu$|Jy beam^−1 for persistent emission at the locations of both FRBs 20190711A and 20171019A with MeerKAT. However, we detected an almost unresolved (ratio of integrated flux to peak flux is ∼1.7 beam) radio emission, where the synthesized beam size was ∼ 8 arcsec size with a peak brightness of |$\sim 53\, \mu$|Jy beam^−1 at MeerKAT and |$\sim 86\, \mu$|Jy beam^−1 at e-MERLIN, possibly associated with FRB 20190714A at z = 0.2365. This represents the first detection of persistent continuum radio emission potentially associated with a (as-yet) non-repeating FRB. If the association is confirmed, one of the strongest remaining distinction between repeaters and non-repeaters would no longer be applicable. A parallel search for repeat bursts from these FRBs revealed no new detections down to a fluence of 0.08 Jy ms for a 1 ms duration burst., Published by Oxford Univ. Press, Oxford

Published
2023
Full Text
View/download PDF

2. Cherenkov Telescope Array : the World’s largest VHE gamma-ray observatory

Author

Roberta Zanin, H. Abdalla, H. Abe, S. Abe, A. Abusleme, F. Acero, A. Acharyya, V. Acin Portella, K. Ackley, R. Adam, C. Adams, S.S. Adhikari, I. Aguado Ruesga, I. Agudo, R. Aguilera, A. Aguirre Santaella, F. Aharonian, A. Alberdi, R. Alfaro, J. Alfaro, C. Alispach, R. Aloisio, R. Alves Batista, J.P. Amans, L. Amati, E. Amato, L. Ambrogi, G. Ambrosi, M. Ambrosio, R. Ammendola, J. Anderson, M. Anduze, E.O. Anguner, L.A. Antonelli, V. Antonuccio, P. Antoranz, R. Anutarawiramkul, J. Aragunde Gutierrez, C. Aramo, A. Araudo, M. Araya, A. Arbet Engels, C. Arcaro, V. Arendt, C. Armand, T. Armstrong, F. Arqueros, L. Arrabito, B. Arsioli, M. Artero, K. Asano, Y. Ascasibar, J. Aschersleben, M. Ashley, P. Attina, P. Aubert, C. B. Singh, D. Baack, A. Babic, M. Backes, V. Baena, S. Bajtlik, A. Baktash, C. Balazs, M. Balbo, O. Ballester, J. Ballet, B. Balmaverde, A. Bamba, R. Bandiera, A. Baquero Larriva, P. Barai, C. Barbier, V. Barbosa Martins, M. Barcelo, M. Barkov, M. Barnard, L. Baroncelli, U. Barres de Almeida, J.A. Barrio, D. Bastieri, P.I. Batista, I. Batkovic, C. Bauer, R. Bautista González, J. Baxter, U. Becciani, J. Becerra González, Y. Becherini, G. Beck, J. Becker Tjus, W. Bednarek, A. Belfiore, L. Bellizzi, R. Belmont, W. Benbow, D. Berge, E. Bernardini, M.I. Bernardos, K. Bernlöhr, A. Berti, M. Berton, B. Bertucci, V. Beshley, N. Bhatt, S. Bhattacharyya, W. Bhattacharyya, B. Y. Bi, G. Bicknell, N. Biederbeck, C. Bigongiari, A. Biland, R. Bird, E. Bissaldi, J. Biteau, M. Bitossi, O. Blanch, M. Blank, J. Blazek, J. Bobin, C. Boccato, F. Bocchino, C. Boehm, M. Bohacova, C. Boisson, J. Boix, J.P. Bolle, J. Bolmont, G. Bonanno, C. Bonavolontà, L. Bonneau Arbeletche, G. Bonnoli, P. Bordas, J. Borkowski, R. Bose, D. Bose, Z. Bosnjak, E. Bottacini, Markus Böttcher, M.T. Botticella, C. Boutonnet, F. Bouyjou, V. Bozhilov, E. Bozzo, L. Brahimi, C. Braiding, S. Brau Nogue, S. Breen, J. Bregeon, M. Breuhaus, A. Brill, W. Brisken, E. Brocato, A.M. Brown, K. Brügge, P. Brun, F. Brun, L. Brunetti, G. Brunetti, P. Bruno, A. Bruno, A. Bruzzese, N. Bucciantini, J. H. Buckley, R. Bühler, A. Bulgarelli, T. Bulik, M. Bünning, M. Bunse, M. Burton, A. Burtovoi, M. Buscemi, S. Buschjager, G. Busetto, J. Buss, K. Byrum, A. Caccianiga, F. Cadoux, A. Calanducci, C. Calderon, J. Calvo Tovar, R. A. Cameron, P. Campana, R. Canestrari, F. Cangemi, B. Cantlay, M. Capalbi, M. Capasso, M. Cappi, A. Caproni, R. Capuzzo Dolcetta, P. Caraveo, V. Cárdenas, L. Cardiel, M. Cardillo, C. Carlile, S. Caroff, R. Carosi, A. Carosi, E. Carquin, M. Carrere, J.M. Casandjian, S. Casanova, F. Cassol, F. Catalani, O. Catalano, D. Cauz, A. Ceccanti, C. Celestino Silva, K. Cerny, M. Cerruti, E. Chabanne, P. Chadwick, Y. Chai, P. Chambery, C. Champion, S. Chaty, A. Chen, K. Cheng, M. Chernyakova, G. Chiaro, A. Chiavassa, M. Chikawa, V.R. Chitnis, J. Chudoba, L. Chytka, S. Cikota, A. Circiello, P. Clark, M. Colak, E. Colombo, S. Colonges, A. Comastri, A. Compagnino, V. Conforti, E. Congiu, R. Coniglione, J. Conrad, F. Conte, J.L. Contreras, P. Coppi, R. Cornat, J. Coronado Blazquez, J. Cortina, A. Costa, H. Costantini, G. Cotter, B. Courty, S. Covino, S. Crestan, P. Cristofari, R. Crocker, J. Croston, K. Cubuk, O. Cuevas, X. Cui, G. Cusumano, S. Cutini, G. D'Amico, F. D'Ammando, P. D'Avanzo, P. Da Vela, M. Dadina, S. Dai, M. Dalchenko, M. Dall'Ora, M.K. Daniel, J. Dauguet, I. Davids, J. Davies, B. Dawson, A. De Angelis, A.E. de Araujo Carvalho, M. de Bony de Lavergne, G. De Cesare, F. de Frondat, I. de la Calle, E. de Gouveia Dal Pino, B. De Lotto, A. De Luca, D. De Martino, M. de Naurois, E. de Ona Wilhelmi, F. De Palma Persio, N. De Simone, V. de Souza Valle, E. Delagnes, G. Deleglise Reznicek, C. Delgado, A.G. Delgado Giler, J. Delgado Mengual Valle, Domenico Della Volpe, D. Depaoli, J. Devin, T. Di Girolamo, C. Di Giulio Pierro, L. Di Venere, C. Díaz, C. Dib, S. Diebold, S. Digel, A. Djannati Atai, J. Djuvsland, A. Dmytriiev, K. Docher, A. Domínguez, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, Rita Cassia dos Anjos, J.L. Dournaux, T. Downes, G. Drake, H. Drass, D. Dravins, C. Duangchan, A. Duara, G. Dubus, L. Ducci, C. Duffy, D. Dumora, K. Dundas Mora, A. Durkalec, V.V. Dwarkadas, J. Ebr, C. Eckner, J. Eder, E. Edy, K. Egberts, S. Einecke, C. Eleftheriadis, D. Elsässer, G. Emery, D. Emmanoulopoulos, J.P. Ernenwein, M. Errando, P. Escarate, J. Escudero, C. Espinoza, S. Ettori, A. Eungwanichayapant, P. Evans, C. Evoli, M. Fairbairn, D. Falceta Goncalves, A. Falcone, V. Fallah Ramazanı, R. Falomo, K. Farakos, G. Fasola, A. Fattorini, Y. Favre, R. Fedora, E. Fedorova, K. Feijen, Q. Feng, G. Ferrand, G. Ferrara, O. Ferreira, M. Fesquet, E. Fiandrini, A. Fiasson, M. Filipovic, D. Fink, J.P. Finley, V. Fioretti, D.F.G. Fiorillo, M. Fiorini, S. Flis, H. Flores, L. Foffano, C. Fohr, M.V. Fonseca, L. Font, G. Fontaine, O. Fornieri, P. Fortin, L. Fortson, N. Fouque, B. Fraga, A. Franceschini, F.J. Franco, L. Freixas Coromina, L. Fresnillo, D. Fugazza, Y. Fujita, S. Fukami, Y. Fukazawa, D. Fulla, S. Funk, A. Furniss, S. Gabici, D. Gaggero, G. Galanti, P. Galdemard, Y. A. Gallant, D. Galloway, S. Gallozzi, V. Gammaldi, R. Garcia, L. E. García-Muñoz, E. Garcia Lopez, F. Gargano, C. Gargano, S. Garozzo, D. Gascon, T. Gasparetto, D. Gasparrini, H. Gasparyan, M. Gaug, N. Geffroy, A. Gent, S. Germani, A. Ghalumyan, A. Ghedina, G. Ghirlanda, F. Gianotti, S. Giarrusso, M. Giarrusso, G. Giavitto, B. Giebels, N. Giglietto, V. Gika, F. Gillardo, R. Gimenes, F. Giordano, E. Giro, M. Giroletti, Andrea Giuliani, M. Gjaja, J.F. Glicenstein, P. Gliwny, H. Goksu, P. Goldoni, J.L. Gomez, M.M. Gonzalez, Juan Manuel Gonzalez, K.S. Gothe, D. Gotz Coelho, T. Grabarczyk, R. Graciani, P. Grandi, G. Grasseau, D. Grasso, D. Green, J. Green, T. Greenshaw, P. Grespan, A. Grillo, M.H. Grondin, J. Grube, V. Guarino, B. Guest, O. Gueta, M. Günduz, S. Gunji, G. Gyuk, J. Hackfeld, D. Hadasch, L. Hagge, A. Hahn, J.E. Hajlaoui, A. Halim, P. Hamal, W. Hanlon, Y. Harada, M.J. Hardcastle, M. Harvey Collado, T. Haubold, A. Haupt, M. Havelka, K. Hayashi, M. Hayashida, H. He, L. Heckmann, M. Heller, F. Henault, Gilles Henri, G. Hermann, S. Hernández Cadena, J. Herrera Llorente, O. Hervet, J. Hinton, A. Hiramatsu, K. Hirotani, B. Hnatyk, R. Hnatyk, J.K. Hoang, D. H.H. Hoffmann, C. Hoischen, J. Holder, M. Holler, B. Hona, D. Horan, Dieter Horns, P. Horvath, J. Houles, M. Hrabovsky, D. Hrupec, Y. Huang, J.‑M. Huet, G. Hughes, G. Hull, T.B. Humensky, M. Hütten, M. Iarlori, J.M. Illa, R. Imazawa, T. Inada, F. Incardona, A. Ingallinera, S. Inoue, T. Inoue, Y. Inoue, F. Iocco, K. Ioka, M. Ionica, S. Iovenitti, A. Iriarte, K. Ishio, W. Ishizaki, Y. Iwamura, J. Jacquemier, M. Jacquemont, M. Jamrozy, P. Janecek, F. Jankowsky, A. JardinBlicq, C. Jarnot, P. Jean Martínez, L. Jocou, N. Jordana, M. Josselin, I. JungRichardt, F.J.P.A. Junqueira, C. Juramy Gilles, P. Kaaret, L.H.S. Kadowaki, M. Kagaya, R. Kankanyan, D. Kantzas, V. Karas, A. Karastergiou, S. Karkar, J. Kasperek, H. Katagiri, J. Kataoka, K. Katarzynski, S. Katsuda, N. Kawanaka, D. Kazanas, D. Kerszberg, B. Khélifi, M.C. Kherlakian, T.P. Kian, D.B. Kieda, T. Kihm, S. Kim, S. Kisaka, R. Kissmann, R. Kleijwegt, G. Kluge, W. Kluźniak, J. Knapp, A. Kobakhidze, Y. Kobayashi, B. Koch, J. Kocot, K. Kohri, N. Komin, A. Kong, K. Kosack, F. Krack, M. Krause, F. Krennrich, H. Kubo, V. N. Kudryavtsev, S. Kunwar, J. Kushida, P. Kushwaha, Barbera Parola, G. La Rosa, R. Lahmann, A. Lamastra, M. Landoni, D. Landriu, R.G. Lang, J. Lapington, P. Laporte, P. Lason, J. Lasuik, J. Lazendic Galloway, T. Le Flour, P. Le Sidaner, S. Leach, S.H. Lee, W.H. Lee, S. Lee Oliveira, A. Lemiere, M. Lemoine Goumard, J.P. Lenain, F. Leone, V. Leray, G. Leto, F. Leuschner, R. Lindemann, E. Lindfors, L. Linhoff, I. Liodakis, A. Lipniacka, M. Lobo, Thomas Lohse, S. Lombardi, A. Lopez, M. Lopez, R. Lopez Coto, F. Louis, M. Louys, F. Lucarelli, H. Ludwig Boudi, P.L. Luque Escamilla, M.C. Maccarone, E. Mach, A.J. Maciejewski, J. Mackey, P. Maeght, C. Maggio, G. Maier, P. Majumdar, M. Makariev, M. Mallamaci, R. Malta Nunes de Almeida, D. Malyshev, D. Mandat, G. Maneva, M. Manganaro, P. Manigot, K. Mannheim, N. Maragos, D. Marano, M. Marconi, A. Marcowith, M. Marculewicz, B. Marcun, J. Marin, N. Marinello, P. Marinos, S. Markoff, P. Marquez, G. Marsella, J. M. Martin, P. G. Martin, M. Martinez, G. Martinez, O. Martinez, H. Martinez Huerta, C. Marty, R. Marx, N. Masetti, P. Massimino, H. Matsumoto, N. Matthews, G. Maurin, W. Max Moerbeck, N. Maxted, M.N. Mazziotta, S.M. Mazzola, J.D. Mbarubucyeye, L. Mc Comb, I. McHardy, S. McKeague, S. McMuldroch, E. Medina, D. Medina Miranda, A. Melandri, C. Melioli, D. Melkumyan, S. Menchiari, S. Mereghetti, G. Merino Arevalo, E. Mestre, J.L. Meunier, T. Meures, S. Micanovic, M. Miceli, M. Michailidis, J. Michalowski, T. Miener, I. Mievre, J. D. Miller, T. Mineo, M. Minev, J.M. Miranda, A. Mitchell, T. Mizuno, B. A. Mode, R. Moderski, L. Mohrmann, E. Molinari, T. Montaruli, I. Monteiro, C. Moore, A. Moralejo, D. Morcuende Parrilla, E. Moretti, K. Mori, P. Moriarty, K. Morik, P. Morris, A. Morselli, K. Mosshammer, R. Mukherjee, J. Muller, C. Mundell, J. Mundet, T. Murach, A. Muraczewski, H. Muraishi, I. Musella, A. Musumarra, A. Nagai, S. Nagataki, T. Naito, T. Nakamori, K. Nakashima, K. Nakayama, N. Nakhjiri, G. Naletto, D. Naumann, L. Nava, M.A. Nawaz, H. Ndiyavala, D. Neise, L. Nellen, R. Nemmen, N. Neyroud, K. Ngernphat, T. Nguyen Trung, L. Nicastro, L. Nickel, J. Niemiec, D. Nieto, C. Nigro, M. Nikołajuk, D. Ninci, K. Noda, Y. Nogami, S. Nolan, R. P. Norris, D. Nosek, M. Nöthe, V. Novotny, S. Nozaki, F. Nunio, P. O'Brien, K. Obara, Y. Ohira, M. Ohishi, S. Ohm, T. Oka, N. Okazaki, A. Okumura, C. Oliver, G. Olivera, B. Olmi, M. Orienti, R. Orito, M. Orlandini, E. Orlando, J.P. Osborne, M. Ostrowski, N. Otte, E. Ovcharov, E. Owen, I. Oya, A. Ozieblo, M. Padovani, A. Pagliaro, A. Paizis, M. Palatiello, M. Palatka, E. Palazzi, J.‑L. Panazol, D. Paneque, S. Panny, Francesca Romana Pantaleo, M. Panter, M. Paolillo, A. Papitto, A. Paravac, J.M. Paredes, G. Pareschi, N. Parmiggiani, R.D. Parsons, P. Paśko, S. R. Patel, B. Patricelli, L. Pavletic, S. Pavy, A. Peer, M. Pecimotika, M.G. Pellegriti, P. Peñil Del Campo, A. Pepato, S. Perard, C. Perennes, M. Peresano, A. Perez Aguilera, J. Perez Romero, M.A. Perez Torres, M. Persic, P. O. Petrucci, O. Petruk, B. Peyaud, K. Pfrang, E. Pian, P. Piatteli, E. Pietropaolo, R. Pillera, D. Pimentel, F. Pintore, C. Pio Garcia, G. Pirola, F. Piron, S. Pita, M. Pohl, V. Poireau, A. Pollo, M. Polo, C. Pongkitivanichkul, J. Porthault, J. Powell, D. Pozo, R.R. Prado, E. Prandini, J. Prast, K. Pressard, G. Principe, N. Produit, D. Prokhorov, H. Prokoph, H. Przybilski, E. Pueschel, G. Pühlhofer, I. Puljak, M.L. Pumo, M. Punch, F. Queiroz, J. Quinn, A. Quirrenbach, P.J. Rajda, R. Rando, S. Razzaque, S. Recchia, P. Reichherzer, O. Reimer, A. Reisenegger, Q. Remy, M. Renaud, T. Reposeur, B. Reville, J.M. Reymond, J. Reynolds, D. Ribeiro, M. Ribo, G. Richards, J. Rico, F. Rieger, L. Riitano, M. Riquelme, D. Riquelme, S. Rivoire, V. Rizi, E. Roache, M. Roche, J. Rodriguez, G. Rodriguez Fernandez, J.C. Rodriguez Ramirez, J.J. Rodriguez Vazquez, G. Rojas, P. Romano, G. Romeo Lobato, C. Romoli, M. Roncadelli, J. Rosado, A. Rosales de Leon, G. Rowell, A. Rugliancich, J.E. Ruiz del Mazo, C. Rulten, C. Russell, F. Russo Hatlen, S. Safi Harb, L. Saha, V. Sahakian, S. Sailer, T. Saito, N. Sakaki, S. Sakurai, G. Salina, H. Salzmann, D. Sanchez, H. Sandaker, A. Sandoval, P. Sangiorgi, M. Sanguillon, H. Sano, M. Santander, A. Santangelo, R. Santos Lima, A. Sanuy, L. Sapozhnikov, T. Saric, S. Sarkar, H. Sasaki, N. Sasaki, Y. Sato, F.G. Saturni, M. Sawada, J. Schaefer, A. Scherer, J. Scherpenberg, P. Schipani, B. Schleicher, J. Schmoll, M. Schneider, H. Schoorlemmer, P. Schovanek, F. Schussler, B. Schwab, U. Schwanke, J. Schwarz, E. Sciacca, S. Scuderi, M. Seglar Arroyo, I. Seitenzahl, D. Semikoz, O. Sergijenko, J.E. Serna Franco, Karol Seweryn, V. Sguera, A. Shalchi, R.Y. Shang, P. Sharma, L. Sidoli, J. Sieiro, H. Siejkowski, A. Sillanpaa, B.B. Singh, K.K. Singh, A. Sinha, C. Siqueira, J. Sitarek, P. Sizun, V. Sliusar, D. Sobczynska, R.W. Sobrinho, H. Sol, G. Sottile, H. Spackman, S. Spencer, G. Spengler, D. Spiga, W. Springer, A. Stamerra, S. Stanic, R. Starling, Ł. Stawarz, Stanislav Stefanik, C. Stegmann, A. Steiner, S. Steinmassl, C. Stella, R. Sternberger, M. Sterzel, C. Stevens, B. Stevenson, T. Stolarczyk, G. Stratta, U. Straumann, J. Striskovic, M. Strzys, R. Stuik, M. Suchenek, Y. Sunada, Tiina Suomijarvi, T. Suric, H. Suzuki, P. Swierk, T. Szepieniec, K. Tachihara, G. Tagliaferri, H. Tajima, N. Tajima, D. Tak, H. Takahashi, M. Takahashi, J. Takata, R. Takeishi, T. Tam, M. Tanaka, T. Tanaka, S. Tanaka, M. Tavani, F. Tavecchio, T. Tavernier, A. Russ Taylor, L.A. Tejedor, P. Temnikov, K. Terauchi, J.C. Terrazas, R. Terrier, T. Terzic, M. Teshima, D. Thibaut, F. Thocquenne, W. Tian, L. Tibaldo, A. Tiengo, M. Tluczykont, C.J. Todero Peixoto, K. Toma, L. Tomankova, J. Tomastik, M. Tornikoski, D.F. Torres, E. Torresi, G. Tosti, L. Tosti, N. Tothill, F. Toussenel, G. Tovmassian, C. Trichard, M. Trifoglio, A. Trois, S. Truzzi, A. Tsiahina, B. Turk, A. Tutone, Y. Uchiyama, P. Utayarat, L. Vaclavek, M. Vacula, V. Vagelli, F. Vagnetti, J.A. Valdivia, M. Valentino, A. Valio, B. Vallage, P. Vallania Quispe, A.M. van den Berg, W. van Driel, C. van Eldik, C. van Rensburg, Brian van Soelen, J. Vandenbroucke, G. Vasileiadis, V. Vassiliev, M. Vazquez Acosta, M. Vecchi, A. Vega, J. Veh, P. Veitch, C. Venter, S. Ventura, S. Vercellone, V. Verguilov, G. Verna, S. Vernetto, V. Verzi, G.P. Vettolani, C. Veyssiere, I. Viale, A. Viana, N. Viaux, J. Vignatti, C.F. Vigorito, J. Villanueva, V. Vitale, V. Vittorini, V. Vodeb, N. Vogel, V. Voisin, S. Vorobiov, M. Vrastil, T. Vuillaume, S.J. Wagner, P. Wagner, K. Wakazono, S.P. Wakely, M. Ward, D. Warren, J. Watson, M. Wechakama, P. Wegner, A. Weinstein, C. Weniger, F. Werner, H. Wetteskind, M. L. White, A. Wierzcholska, S. Wiesand, R. Wijers, M. Wilkinson, M. Will, J. Williams, T. J. Williamson, A. Wolter, Y.W. Wong, M. Wood, T. Yamamoto, H. Yamamoto, Y. Yamane, R. Yamazaki, S. Yanagita, L. Yang, S. Yoo, T. Yoshida, T. Yoshikoshi, P. Yu, A. Yusafzai, Michael Zacharias, B. Zaldivar, L. Zampieri, R. Zanin, R. Zanmar Sanchez, D. Zaric, M. Zavrtanik, D. Zavrtanik, Andrzej Zdziarski, A. Zech, H. Zechlin, A. Zenin, A. Zerwekh, K. Ziętara, A. Zink, J. Ziolkowski, M. Zivec, A. Zmija, Współautorami artykułu są członkowie CTA Observatory, CTA Consortium i LST Collaboration w liczbie 1139, Astronomy, Research unit Nuclear & Hadron Physics, and Research unit Astroparticle Physics

Subjects
Physics, Observatory, Gamma ray, Astronomy
Abstract

Very-high Energy (VHE) gamma-ray astroparticle physics is a relatively young field, and observations over the past decade have surprisingly revealed almost two hundred VHE emitters which appear to act as cosmic particle accelerators. These sources are an important component of the Universe, influencing the evolution of stars and galaxies. At the same time, they also act as a probe of physics in the most extreme environments known - such as in supernova explosions, and around or after the merging of black holes and neutron stars. However, the existing experiments have provided exciting glimpses, but often falling short of supplying the full answer. A deeper understanding of the TeV sky requires a significant improvement in sensitivity at TeV energies, a wider energy coverage from tens of GeV to hundreds of TeV and a much better angular and energy resolution with respect to the currently running facilities. The next generation gamma-ray observatory, the Cherenkov Telescope Array Observatory (CTAO), is the answer to this need. In this talk I will present this upcoming observatory from its design to the construction, and its potential science exploitation. CTAO will allow the entire astronomical community to explore a new discovery space that will likely lead to paradigm-changing breakthroughs. In particular, CTA has an unprecedented sensitivity to short (sub-minute) timescale phenomena, placing it as a key instrument in the future of multi-messenger and multi-wavelength time domain astronomy. I will conclude the talk presenting the first scientific results obtained by the LST-1, the prototype of one CTAO telescope type - the Large-Sized Telescope, that is currently under commission., PoS: Proceedings of Science, 395, ISSN:1824-8039, Proceedings of 37th International Cosmic Ray Conference (ICRC2021)

Published
2022

3. Resolving the Crab pulsar wind nebula at teraelectronvolt energies

Author

Natalia Żywucka, M. de Naurois, T. Chand, Frank M. Rieger, J. Bolmont, S. Colafrancesco, Ruizhi Yang, W. Kluźniak, S. Eschbach, Jim Hinton, R. Simoni, Dmitry Khangulyan, Christopher J. Moore, G. Fontaine, M. Büchele, D. A. Sanchez, T. Tavernier, L. Mohrmann, Denys Malyshev, J. Veh, S. Klepser, B. Khélifi, H. M. Schutte, C. Perennes, D. Glawion, Christoph Deil, Mohanraj Senniappan, A.A. Zdziarski, A. Djannati-Ataï, Y.A. Gallant, Gavin Rowell, Stefan Funk, T. Takahashi, Gianluca Giavitto, Axel Donath, A. W. Chen, M. Bryan, J. Dyks, D. Zaborov, I. Oya, G. Heinzelmann, K. Shiningayamwe, T. Lohse, Yvonne Becherini, M. Renaud, H. Iwasaki, M. Holler, J.-P. Ernenwein, P. Vincent, R. D. Parsons, G. Emery, H. Odaka, Christo Venter, D. Huber, M. Arakawa, D. Berge, M. Capasso, Matteo Cerruti, Nachiketa Chakraborty, F. Niederwanger, A. Marcowith, A. Zech, E. Leser, Jacco Vink, R. Rauth, Sabrina Casanova, C. Arcaro, I. Jung-Richardt, T. Vuillaume, G. Hermann, D. Gottschall, Werner Hofmann, Regis Terrier, J. Becker Tjus, A. Schulz, Carlo Romoli, M. Panter, M. Seglar-Arroyo, H. Ndiyavala, B. van Soelen, Felix Aharonian, M. Haupt, Lukasz Stawarz, Michael Punch, V. Doroshenko, M. Spir-Jacob, R. Tuffs, R. C. G. Chaves, E. O. Angüner, A. Priyana Noel, L. O'c. Drury, S. Saito, J.F. Glicenstein, D. J. van der Walt, S. Raab, Andreas Quirrenbach, C. Steppa, J.-P. Lenain, N. Shafi, K. Egberts, Robert Wagner, K. Kosack, J. Hahn, Reinhard Schlickeiser, M. Tsirou, G. Vasileiadis, M. Kraus, S. Chandra, S. Nakashima, G. Martí-Devesa, M. Katsuragawa, Ruben Lopez-Coto, M.-H. Grondin, M. Böttcher, R. Blackwell, E. Ruiz-Velasco, L. Dirson, Stefan Ohm, Léa Jouvin, S. Pita, F. Schüssler, P. deWilt, J. King, F. Voisin, Julien Lefaucheur, A. Dmytriiev, R. Moderski, S. Gabici, A. Fiasson, J. Lau, L. Oakes, I.D. Davids, Alison Mitchell, L. Rinchiuso, P.J. Meintjes, Heike Prokoph, Zorawar Wadiasingh, R. J. White, S. Fegan, Dieter Horns, V. Poireau, Monica Barnard, P.-O. Petrucci, H. Abdalla, D. Jankowsky, Q. Piel, C. Stegmann, Nu. Komin, Marek Jamrozy, Catherine Boisson, Helene Sol, Pierre Brun, A.S. Seyffert, A. Carosi, M. Füßling, M.A. Kastendieck, S. Bonnefoy, N. Tsuji, F. Gaté, J. Devin, G. Henri, D. A. Prokhorov, D. Tiziani, C. Hoischen, Ullrich Schwanke, A. Specovius, R. Steenkamp, A. Reimer, J. Bregeon, Francois Brun, B. Condon, Michael Backes, H. Yoneda, Tim Holch, M. Tluczykont, E. Moulin, Tomasz Bulik, T. Bylund, A. Jacholkowska, S. Caroff, Celine Armand, F. Jankowsky, Stefan Wagner, Yasunobu Uchiyama, C. van Rensburg, M. Zacharias, C. Trichard, F. Ait Benkhali, Manami Sasaki, S. Schwemmer, Andrea Santangelo, A. Ziegler, G. Maurin, A. Wierzcholska, C. Mariaud, Jacek Niemiec, Olaf Reimer, Thomas Murach, A. Lemière, M. Lemoine-Goumard, I. Shilon, Heinrich J. Völk, R. Marx, P. Bordas, I. Lypova, G. Lamanna, J. Zorn, U. Katz, J.-P. Tavernet, B. Rudak, V. Marandon, K. Katarzyński, A.M. Taylor, V. Sahakian, M. Mohamed, M. Ostrowski, Konrad Bernlöhr, B. Peyaud, G. Pühlhofer, R. Zanin, P. T. O'Brien, Atreyee Sinha, C. van Eldik, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, H.E.S.S., Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), European Commission, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Armagh Observatory, Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Faculty of Science, High Energy Astrophys. & Astropart. Phys (API, FNWI), Gravitation and Astroparticle Physics Amsterdam, 26598973 - Abdalla, Hassan, 30588766 - Arcaro, Cornelia, 28644743 - Backes, Michael, 20574266 - Barnard, Monica, 24420530 - Böttcher, Markus, 30366755 - Chand, Tej B., 31125417 - Chandra, Sunil, 26403366 - Ndiyavala, Hambeleleni, 10060499 - Van der Walt, Diederick Johannes, 12006653 - Venter, Christo, 26594080 - Wadiasingh, Zorawar, 22799133 - Schutte, Hester M., 20126999 - Seyffert, Albertus Stefanus, 29092086 - Zacharias, Michael, and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Electromagnetic spectrum, electron: relativistic, magnetic field, Astrophysics, positron: energy, 01 natural sciences, 7. Clean energy, Pulsar wind nebula, particle: acceleration, Raigs gamma, Astrophysics::Solar and Stellar Astrophysics, HESS - Abteilung Hofmann, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, pulsar, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, [PHYS]Physics [physics], Nebula, radio wave, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 4. Education, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], photon, Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, High-energy astrophysics, Particle astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Camps magnètics, accelerator, High-energy astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, gap, X-ray, energy loss: rotation, Pulsar, 0103 physical sciences, synchrotron, Astrophysics::Galaxy Astrophysics, gamma ray: energy, 0105 earth and related environmental sciences, Crab Pulsar, Gamma rays, Astronomy and Astrophysics, Crab Nebula, electromagnetic, gamma ray: VHE, [SDU]Sciences of the Universe [physics], Magnetic fields, ddc:520, Physics::Accelerator Physics
Abstract

arXiv:1909.09494v2, H.E.S.S. Collaboration: et al., The support of the Namibian authorities and of the University of Namibia in facilitating the construction and operation of H.E.S.S. is gratefully acknowledged, as is the support by the German Ministry for Education and Research (BMBF), the Max Planck Society, the German Research Foundation (DFG), the Helmholtz Association, the Alexander von Humboldt Foundation, the French Ministry of Higher Education, Research and Innovation, the Centre National de la Recherche Scientifique (CNRS/IN2P3 and CNRS/INSU), the Commissariat à l’énergie atomique et aux énergies alternatives (CEA), the UK Science and Technology Facilities Council (STFC), the Knut and Alice Wallenberg Foundation, the National Science Centre, Poland (grant number 2016/22/M/ST9/00382), the South African Department of Science and Technology and the National Research Foundation, the University of Namibia, the National Commission on Research, Science and Technology of Namibia (NCRST), the Austrian Federal Ministry of Education, Science and Research and the Austrian Science Fund (FWF), the Australian Research Council (ARC), the Japan Society for the Promotion of Science and the University of Amsterdam. We appreciate the excellent work of the technical support staff in Berlin, Zeuthen, Heidelberg, Palaiseau, Paris, Saclay, Tübingen and Namibia in the construction and operation of the equipment. This work benefited from services provided by the H.E.S.S. Virtual Organisation, supported by the national resource providers of the EGI Federation. R.C.G.C. was funded by EU FP7 Marie Curie (grant agreement number PIEF-GA-2012-332350).

Published
2020
Full Text
View/download PDF

4. A very-high-energy component deep in the $\gamma$-ray burst afterglow

Author

H. Abdalla, R. Adam, F. Aharonian, F. Ait Benkhali, E. O. Angüner, M. Arakawa, C. Arcaro, C. Armand, H. Ashkar, M. Backes, V. Barbosa Martins, M. Barnard, Y. Becherini, D. Berge, K. Bernlöhr, E. Bissaldi, R. Blackwell, M. Böttcher, C. Boisson, J. Bolmont, S. Bonnefoy, J. Bregeon, M. Breuhaus, F. Brun, P. Brun, M. Bryan, M. Büchele, T. Bulik, T. Bylund, M. Capasso, S. Caroff, A. Carosi, S. Casanova, M. Cerruti, T. Chand, S. Chandra, A. Chen, S. Colafrancesco, M. Curyło, I. D. Davids, C. Deil, J. Devin, P. deWilt, L. Dirson, A. Djannati-Ataï, A. Dmytriiev, A. Donath, V. Doroshenko, J. Dyks, K. Egberts, G. Emery, J.-P. Ernenwein, S. Eschbach, K. Feijen, S. Fegan, A. Fiasson, G. Fontaine, S. Funk, M. Füßling, S. Gabici, Y. A. Gallant, F. Gaté, G. Giavitto, L. Giunti, D. Glawion, J. F. Glicenstein, D. Gottschall, M.-H. Grondin, J. Hahn, M. Haupt, G. Heinzelmann, G. Henri, G. Hermann, J. A. Hinton, W. Hofmann, C. Hoischen, T. L. Holch, M. Holler, D. Horns, D. Huber, H. Iwasaki, M. Jamrozy, D. Jankowsky, F. Jankowsky, A. Jardin-Blicq, I. Jung-Richardt, M. A. Kastendieck, K. Katarzyński, M. Katsuragawa, U. Katz, D. Khangulyan, B. Khélifi, J. King, S. Klepser, W. Kluźniak, Nu. Komin, K. Kosack, D. Kostunin, M. Kreter, G. Lamanna, A. Lemière, M. Lemoine-Goumard, J.-P. Lenain, E. Leser, C. Levy, T. Lohse, I. Lypova, J. Mackey, J. Majumdar, D. Malyshev, V. Marandon, A. Marcowith, A. Mares, C. Mariaud, G. Martí-Devesa, R. Marx, G. Maurin, P. J. Meintjes, A. M. W. Mitchell, R. Moderski, M. Mohamed, L. Mohrmann, C. Moore, E. Moulin, J. Muller, T. Murach, S. Nakashima, M. de Naurois, H. Ndiyavala, F. Niederwanger, J. Niemiec, L. Oakes, P. O’Brien, H. Odaka, S. Ohm, E. de Ona Wilhelmi, M. Ostrowski, I. Oya, M. Panter, R. D. Parsons, C. Perennes, P.-O. Petrucci, B. Peyaud, Q. Piel, S. Pita, V. Poireau, A. Priyana Noel, D. A. Prokhorov, H. Prokoph, G. Pühlhofer, M. Punch, A. Quirrenbach, S. Raab, R. Rauth, A. Reimer, O. Reimer, Q. Remy, M. Renaud, F. Rieger, L. Rinchiuso, C. Romoli, G. Rowell, B. Rudak, E. Ruiz-Velasco, V. Sahakian, S. Sailer, S. Saito, D. A. Sanchez, A. Santangelo, M. Sasaki, R. Schlickeiser, F. Schüssler, A. Schulz, H. M. Schutte, U. Schwanke, S. Schwemmer, M. Seglar-Arroyo, M. Senniappan, A. S. Seyffert, N. Shafi, K. Shiningayamwe, R. Simoni, A. Sinha, H. Sol, A. Specovius, M. Spir-Jacob, Ł. Stawarz, R. Steenkamp, C. Stegmann, C. Steppa, T. Takahashi, T. Tavernier, A. M. Taylor, R. Terrier, D. Tiziani, M. Tluczykont, C. Trichard, M. Tsirou, N. Tsuji, R. Tuffs, Y. Uchiyama, D. J. van der Walt, C. van Eldik, C. van Rensburg, B. van Soelen, G. Vasileiadis, J. Veh, C. Venter, P. Vincent, J. Vink, H. J. Völk, T. Vuillaume, Z. Wadiasingh, S. J. Wagner, R. White, A. Wierzcholska, R. Yang, H. Yoneda, M. Zacharias, R. Zanin, A. A. Zdziarski, A. Zech, A. Ziegler, J. Zorn, N. Żywucka, F. de Palma, M. Axelsson, O. J. Roberts, Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Abdalla, H., Adam, R., Aharonian, F., Ait Benkhali, F., Anguner, E. O., Arakawa, M., Arcaro, C., Armand, C., Ashkar, H., Backes, M., Barbosa Martins, V., Barnard, M., Becherini, Y., Berge, D., Bernlohr, K., Bissaldi, E., Blackwell, R., Bottcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bregeon, J., Breuhaus, M., Brun, F., Brun, P., Bryan, M., Buchele, M., Bulik, T., Bylund, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chand, T., Chandra, S., Chen, A., Colafrancesco, S., Curylo, M., Davids, I. D., Deil, C., Devin, J., Dewilt, P., Dirson, L., Djannati-Atai, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dyks, J., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Feijen, K., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., Fussling, M., Gabici, S., Gallant, Y. A., Gate, F., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huber, D., Iwasaki, H., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Jung-Richardt, I., Kastendieck, M. A., Katarzynski, K., Katsuragawa, M., Katz, U., Khangulyan, D., Khelifi, B., King, J., Klepser, S., Kluzniak, W., Komin, N., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marcowith, A., Mares, A., Mariaud, C., Marti-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moore, C., Moulin, E., Muller, J., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., de Ona Wilhelmi, E., Ostrowski, M., Oya, I., Panter, M., Parsons, R. D., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Priyana Noel, A., Prokhorov, D. A., Prokoph, H., Puhlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schussler, F., Schulz, A., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spir-Jacob, M., Stawarz, L., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Volk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., White, R., Wierzcholska, A., Yang, R., Yoneda, H., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Ziegler, A., Zorn, J., Zywucka, N., de Palma, F., Axelsson, M., Roberts, O. J., Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 26598973 - Abdalla, Hassan, 30588766 - Arcaro, Cornelia, 28644743 - Backes, Michael, 20574266 - Barnard, Monica, 24420530 - Böttcher, Markus, 30366755 - Chand, Tej B., 31125417 - Chandra, Sunil, 26403366 - Ndiyavala, Hambeleleni, 22799133 - Schutte, Hester M., 20126999 - Seyffert, Albertus Stefanus, 10060499 - Van der Walt, Diederick Johannes, 21106266 - Van Rensburg, Carlo, 12006653 - Venter, Christo, 26594080 - Wadiasingh, Zorawar, 29092086 - Zacharias, Michael, 34208968 - Zywucka-Hejzner, Natalia, 33379009 - Kreter, Michael, Faculty of Science, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
electron, Brightness, Photon, Astrophysics::High Energy Astrophysical Phenomena, brightness, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, gamma ray: burst, 7. Clean energy, 01 natural sciences, VHE, Transient astrophysical phenomena, 0103 physical sciences, synchrotron, ddc:530, 010303 astronomy & astrophysics, X-ray: flux, Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Range (particle radiation), Multidisciplinary, 010308 nuclear & particles physics, particle: energy, photon, Gamma ray, Time-domain astronomy, Institut für Physik und Astronomie, Afterglow, High-energy astrophysics, Automatic Keywords, gamma ray: UHE, Orders of magnitude (time), 13. Climate action, Gamma-ray burst, Particle astrophysics, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Gamma-ray bursts (GRBs) are brief flashes of gamma rays, considered to be the most energetic explosive phenomena in the Universe. The emission from GRBs comprises a short (typically tens of seconds) and bright prompt emission, followed by a much longer afterglow phase. During the afterglow phase, the shocked outflow -- produced by the interaction between the ejected matter and the circumburst medium -- slows down, and a gradual decrease in brightness is observed. GRBs typically emit most of their energy via gamma-rays with energies in the kiloelectronvolt-to-megaelectronvolt range, but a few photons with energies of tens of gigaelectronvolts have been detected by space-based instruments. However, the origins of such high-energy (above one gigaelectronvolt) photons and the presence of very-high-energy (more than 100 gigaelectronvolts) emission have remained elussive. Here we report observations of very-high-energy emission in the bright GRB 180720B deep in the GRB afterglow -ten hours after the end of the prompt emission phase, when the X-ray flux had already decayed by four orders of magnitude. Two possible explanations exist for the observed radiation: inverse Compton emission and synchrotron emission of ultrarelativistic electrons. Our observations show that the energy fluxes in the X-ray and gamma-ray range and their photon indices remain comparable to each other throughout the afterglow. This discovery places distinct constraints on the GRB environment for both emission mechanisms, with the inverse Compton explanation alleviating the particle energy requirements for the emission observed at late times. The late timing of this detection has consequences for the future observations of GRBs at the highest energies., Comment: Preprint version of Nature paper. Contacts: E.Ruiz-Velasco, F. Aharonian, E.Bissaldi, C.Hoischen, R.D Parsons, Q.Piel, A.Taylor, D.Khangulyan

Published
2019
Full Text
View/download PDF

5. VHE γ-ray discovery and multi-wavelength study of the blazar 1ES 2322-409

Author

M. Zacharias, Marek Jamrozy, Jim Hinton, A. Schulz, R. Tuffs, R. Simoni, Dmitry Khangulyan, D. A. Sanchez, Helene Sol, H. Ndiyavala, S. Bernhard, J. Devin, M. Böttcher, F. Ait Benkhali, S. Eschbach, C. Stegmann, Nu. Komin, M. Holler, B. van Soelen, Gerd Puehlhofer, F. Jankowsky, J. Veh, D. J. van der Walt, M. Fuessling, M. Lemoine-Goumard, M.A. Kastendieck, S. Bonnefoy, Axel Donath, A. W. Chen, I. Shilon, T. Tavernier, G. Emery, Matteo Cerruti, Michael Punch, M. Spir-Jacob, Manami Sasaki, S. Schwemmer, Andrea Santangelo, J. Lau, B. Peyaud, E. Leser, G. Hermann, Regis Terrier, Carlo Romoli, F. Gaté, R. Rauth, Fabian Schüssler, A. Jacholkowska, M. de Naurois, A. Woernlein, P. Bordas, D. A. Prokhorov, R. Marx, Werner Hofmann, Felix Spanier, Catherine Boisson, Stefan Funk, R. Zanin, R. C. G. Chaves, E. O. Angüner, D. Tiziani, I. Lypova, Stefan Wagner, Yasunobu Uchiyama, Christo Venter, D. Berge, D. Huber, D. Gottschall, P. T. O'Brien, Ullrich Schwanke, C. Perennes, Ruizhi Yang, S. Gabici, C. van Rensburg, J.F. Glicenstein, A. Marcowith, C. Hoischen, Wlodek Kluzniak, S. Saito, G. Fontaine, A. Zech, G. Maurin, K. Kosack, Jacek Niemiec, M. Lorentz, J. Becker Tjus, P.-O. Petrucci, L. Mohrmann, R. Steenkamp, A. Djannati-Ataï, S. Nakashima, Robert Wagner, J. Lefaucheur, A. Wierzcholska, Atreyee Sinha, C. van Eldik, C. Mariaud, A.M. Taylor, Aion Viana, S. Klepser, Olaf Reimer, R. J. White, G. Martí-Devesa, J.-P. Lenain, N. Shafi, Pierre Brun, T. Takahashi, Michael Backes, Gianluca Giavitto, T. Garrigoux, R. Blackwell, J. Hahn, N. Zywucka, Dieter Horns, I.D. Davids, S. Raab, Thomas Murach, E. Ruiz-Velasco, K. Egberts, Tim Holch, Reinhard Schlickeiser, M. Tsirou, G. Henri, A. M. W. Mitche, M. Mohamed, G. Vasileiadis, M. Ostrowski, H. Odaka, S. Chandra, P.J. Meintjes, S. Fegan, Marco Padovani, T. Lohse, A. Reimer, J. Bregeon, M. Renaud, H. Iwasaki, A. Carosi, R. R. Kruger, A. Lemière, H. Abdalla, B. Khélifi, Denys Malyshev, Nachiketa Chakraborty, K. Bernloehr, Stefan Ohm, S. Caroff, S. Pita, E. Moulin, Tomasz Bulik, D. Glawion, M. Panter, T. Bylund, Mohanraj Senniappan, A. Fiasson, L. Dirson, V. Poireau, L. Oakes, I. Sushch, A.A. Zdziarski, I. Jung-Richardt, Yvonne Becherini, D. Kerszberg, Masanori Arakawa, I. Oya, G. Heinzelmann, Felix Aharonian, L. Tibaldo, Zorawar Wadiasingh, B. Condon, Monica Barnard, F. Zefi, M. Buechele, M. Capasso, S. Krakau, V. Sahakian, D. Jankowsky, Q. Piel, J. Zorn, U. Katz, A.S. Seyffert, J.-P. Tavernet, P. Vincent, G. Lamanna, T. Vuillaume, P. deWilt, M. Seglar-Arroyo, J. King, B. Rudak, A. Priyana Noel, A. Dmytriiev, R. Moderski, V. Marandon, K. Katarzyński, L. Rinchiuso, L. Jouvin, M. Katsuragawa, C. Arcaro, M. Kraus, A. Specovius, Francois Brun, M. Tluczykont, Celine Armand, C. Steppa, M. Arrieta, Heike Prokoph, M. Haupt, Lukasz Stawarz, J. Dyks, K. Shiningayamwe, Andreas Quirrenbach, N. Tsuji, C. Trichard, J.-P. Ernenwein, R. D. Parsons, A. Ziegler, L. O. 'C. Drury, Ruben Lopez-Coto, M.-H. Grondin, P. Wagner, C. Dei, Y.A. Gallant, Gavin Rowell, M. Bryan, D. Zaborov, F. Niederwanger, Jacco Vink, Sabrina Casanova, H. J. Voelk, Frank M. Rieger, F. Voisin, J. Bolmont, S. Colafrancesco, Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Collège de France (CdF), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique (ex SAP) (DAP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Electronique et des Technologies de l'Information (CEA-LETI), Université Grenoble Alpes (UGA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), H.E.S.S., H.E.S.S. Collaboration, 26598973 - Abdalla, Hassan, 30588766 - Arcaro, Cornelia, 28644743 - Backes, Michael, 20574266 - Barnard, Monica, 24420530 - Böttcher, Markus, 31125417 - Chandra, Sunil, 26909995 - Garrigoux, Tania, 11749903 - Krüger, Petrus Paulus, 26403366 - Ndiyavala, Hambeleleni, 20126999 - Seyffert, Albertus Stefanus, 25161814 - Spanier, Felix Alexander, 24922986 - Sushch, Iurii, 10060499 - Van der Walt, Diederick Johannes, 21106266 - Van Rensburg, Carlo, 12006653 - Venter, Christo, 26594080 - Wadiasingh, Zorawar, 29092086 - Zacharias, Michael, Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Collège de France (CdF (institution)), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Faculty of Science, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
gamma-rays: galaxies, principal component analysis, Energy flux, Astrophysics, 01 natural sciences, pixel, HESS, ultraviolet, optical, energy: flux, HESS - Abteilung Hofmann, photon: flux, 010303 astronomy & astrophysics, model: leptonic, Physics, radio wave, density, active, [Galaxies], Gamma ray, galaxies [Gamma-rays], individual: 1ES 2322-409 [BL Lacertae objects], active [galaxies], infrared, Spectral energy distribution, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Astrophysics::Cosmology and Extragalactic Astrophysics, gamma ray: energy spectrum, GLAST, blazar, X-ray, 0103 physical sciences, Blazar, Astroparticle physics, non-thermal [Radiation mechanisms], synchrotron radiation, background, 010308 nuclear & particles physics, Institut für Physik und Astronomie, Astronomy and Astrophysics, radiation mechanisms: non-thermal, redshift, proton synchrotron, MAGIC, Redshift, Crab Nebula, gamma ray: VHE, Space and Planetary Science, spectral, ddc:520, High Energy Physics::Experiment, BL Lacertae objects: individual: 1ES 2322−409, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Fermi Gamma-ray Space Telescope
Abstract

著者人数: H.E.S.S. Collaboration 233名 (所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 桂川, 美穂; 中島, 真也; 小高, 裕和; 高橋, 忠幸), Number of authors: H.E.S.S. Collaboration 233 (Affiliation. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS): Katsuragawa, Miho; Nakashima, Shinya; Odaka, Hirokazu; Takahashi, Tadayuki), Accepted: 2018-09-29, 資料番号: SA1180422000

Published
2018
Full Text
View/download PDF

6. HESS J1826$-$130: A Very Hard $\gamma$-Ray Spectrum Source in the Galactic Plane

Author

C. Hoischen, E. O. Angüner, Felix Aharonian, I. Oya, A. Ziegler, Sabrina Casanova, and P. Bordas

Subjects
Physics, Spectral index, Molecular cloud, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Gamma ray, Astrophysics, Electron, Astrophysics::Cosmology and Extragalactic Astrophysics, Galactic plane, Wavelength, Coincident, Physics::Accelerator Physics, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract

HESS J1826$-$130 is an unidentified hard spectrum source discovered by H.E.S.S. along the Galactic plane, the spectral index being $\Gamma$ = 1.6 with an exponential cut-off at about 12 TeV. While the source does not have a clear counterpart at longer wavelengths, the very hard spectrum emission at TeV energies implies that electrons or protons accelerated up to several hundreds of TeV are responsible for the emission. In the hadronic case, the VHE emission can be produced by runaway cosmic-rays colliding with the dense molecular clouds spatially coincident with the H.E.S.S. source., Comment: 6 pages, 3 figures, Proceedings of the 6th International Symposium on High Energy Gamma-Ray Astronomy (Gamma2016), Heidelberg, Germany

Published
2017

7. Expression and secretion of functional miniantibodies McPC603scFvDhlx in cell-wall-less L-form strains of Proteus mirabilis and Escherichia coli : A comparison of the synthesis capacities of L-form strains with an E. coli producer strain

Author

C Hoischen, J Gumpert, M J Kujau, and D Riesenberg

Subjects
Growth medium, biology, Strain (chemistry), L Forms, lac operon, General Medicine, Periplasmic space, medicine.disease_cause, biology.organism_classification, Applied Microbiology and Biotechnology, Enterobacteriaceae, Proteus mirabilis, Recombinant Proteins, Transformation (genetics), chemistry.chemical_compound, chemistry, Biochemistry, Antibody Specificity, Antibody Formation, Escherichia coli, medicine, Transformation, Bacterial, Biotechnology
Abstract

The paper describes the synthesis of the phosphorylcholine-binding miniantibody McPC603scFvDhl x in cell-wall-less L-form strains of Escherichia coli and Proteus mirabilis. Cells of these strains were transformed with the plasmid pACK02scKan, carrying the miniantibody (miniAb) coding sequence under the control of the lac promoter. L-form transformants of both species were able to synthesize the functional miniAb as an extracellular soluble product. The highest quantities were obtained by P. mirabilis L-form strains after induction with 5 mM isopropyl beta-D-thiogalactopyranoside (IPTG). Yields of 45-75 mg/l total antibody protein and of 10-18 mg/l functional miniAb were estimated in the growth medium of shaking cultures 40-80 h after induction with IPTG. About 10% of the active miniAb remained cell-bound. The yields of functional miniAb could be optimized by lowering the growth temperature from 37 degrees C to 26-32 degrees C and by supplementation of the medium with 80 mM sodium fumarate. A comparison of the specific activities revealed that the P. mirabilis L-form strains have a similar synthesis capacity (2-4 mg functional miniAb/g cell dry weight) to that of the producer strain E. coli RV308. The results show that the processes of correct folding and assembling of the miniAb molecules are possible without the periplasmic compartment.

Published
1998
Full Text
View/download PDF

8. Presence of protein constituents of the gram-positive bacterial phosphotransferase regulatory system in Acholeplasma laidlawii

Author

C Hoischen, A Dijkstra, S Rottem, Jonathan Reizer, and Milton H. Saier

Subjects
Phosphatase, macromolecular substances, Protein Serine-Threonine Kinases, Biology, Microbiology, Phosphoenolpyruvate, Phosphotransferase, Adenosine Triphosphate, Allosteric Regulation, Bacterial Proteins, Acholeplasma laidlawii, Phosphoenolpyruvate Sugar Phosphotransferase System, Molecular Biology, chemistry.chemical_classification, Kinase, PEP group translocation, Phosphoproteins, biology.organism_classification, Phosphoric Monoester Hydrolases, carbohydrates (lipids), Enzyme, chemistry, Biochemistry, bacteria, lipids (amino acids, peptides, and proteins), Phosphoenolpyruvate carboxykinase, Acholeplasmataceae, Bacteria, Research Article
Abstract

Acholeplasma species have been reported to lack a functional phosphoenolpyruvate:sugar phosphotransferase system (PTS). We show here that Acholeplasma laidlawii possesses activities of enzyme I, HPr, HPr(ser) kinase, and HPr(ser-P) phosphatase but lacks detectable activities of enzymes II of the PTS. HPr from this organism was purified, and the regulatory properties of the kinase and phosphatase were characterized and shown to differ from those of previously studied bacteria. The results suggest the presence of an incomplete PTS in A. laidlawii which has the potential to function in a unique regulatory capacity.

Published
1993
Full Text
View/download PDF

9. Identification of a phosphoenolpyruvate:fructose phosphotransferase system (fructose-1-phosphate forming) in Listeria monocytogenes

Author

Milton H. Saier, Jonathan Reizer, W J Mitchell, C Hoischen, and Christopher D. Herring

Subjects
Fructose, macromolecular substances, Microbiology, Fructokinase, Fructokinases, chemistry.chemical_compound, Bacterial Proteins, Phosphoenolpyruvate—protein phosphotransferase, Phosphorylation, Enzyme inducer, Phosphoenolpyruvate Sugar Phosphotransferase System, Molecular Biology, biology, Fructosephosphates, Phosphotransferases (Nitrogenous Group Acceptor), PEP group translocation, Listeria monocytogenes, Fructose 1-phosphate, carbohydrates (lipids), chemistry, Biochemistry, Enzyme Induction, biology.protein, bacteria, Phosphoenolpyruvate carboxykinase, Research Article
Abstract

Listeria monocytogenes is a gram-positive bacterium whose carbohydrate metabolic pathways are poorly understood. We provide evidence for an inducible phosphoenolpyruvate (PEP):fructose phosphotransferase system (PTS) in this pathogen. The system consists of enzyme I, HPr, and a fructose-specific enzyme II complex which generates fructose-1-phosphate as the cytoplasmic product of the PTS-catalyzed vectorial phosphorylation reaction. Fructose-1-phosphate kinase then converts the product of the PTS reaction to fructose-1,6-bisphosphate. HPr was shown to be phosphorylated by [32P]PEP and enzyme I as well as by [32P]ATP and a fructose-1,6-bisphosphate-activated HPr kinase like those found in other gram-positive bacteria. Enzyme I, HPr, and the enzyme II complex of the Listeria PTS exhibit enzymatic cross-reactivity with PTS enzyme constituents from Bacillus subtilis and Staphylococcus aureus.

Published
1993
Full Text
View/download PDF

10. Sequence analyses and evolutionary relationships among the energy-coupling proteins enzyme I and HPr of the bacterial phosphoenolpyruvate: Sugar phosphotransferase system

Author

C Hoischen, Jonathan Reizer, Aiala Reizer, Tam N. Pham, and Milton H. Saier

Subjects
Genetics, biology, Protein domain, PEP group translocation, Bacillus subtilis, medicine.disease_cause, biology.organism_classification, Biochemistry, Open reading frame, Codon usage bias, medicine, Phosphoenolpyruvate carboxykinase, Molecular Biology, Escherichia coli, Peptide sequence
Abstract

We have previously reported the overexpression, purification, and biochemical properties of the Bacillus subtilis Enzyme I of the phosphoenolpyruvate: sugar phosphotransferase system (PTS) (Reizer, J., et al., 1992, J. Biol. Chem. 267, 9158-9169). We now report the sequencing of the ptsI gene of B. subtilis encoding Enzyme I (570 amino acids and 63,076 Da). Putative transcriptional regulatory signals are identified, and the pts operon is shown to be subject to carbon source-dependent regulation. Multiple alignments of the B. subtilis Enzyme I with (1) six other sequenced Enzymes I of the PTS from various bacterial species, (2) phosphoenolpyruvate synthase of Escherichia coli, and (3) bacterial and plant pyruvate: phosphate dikinases (PPDKs) revealed regions of sequence similarity as well as divergence. Statistical analyses revealed that these three types of proteins comprise a homologous family, and the phylogenetic tree of the 11 sequenced protein members of this family was constructed. This tree was compared with that of the 12 sequence HPr proteins or protein domains. Antibodies raised against the B. subtilis and E. coli Enzymes I exhibited immunological cross-reactivity with each other as well as with PPDK of Bacteroides symbiosus, providing support for the evolutionary relationships of these proteins suggested from the sequence comparisons. Putative flexible linkers tethering the N-terminal and the C-terminal domains of protein members of the Enzyme I family were identified, and their potential significance with regard to Enzyme I function is discussed. The codon choice pattern of the B. subtilis and E. coli ptsI and ptsH genes was found to exhibit a bias toward optimal codons in these organisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Published
1993
Full Text
View/download PDF

11. Bacterial L-forms

Author

E J, Allan, C, Hoischen, and J, Gumpert

Subjects
Bacteria, Protoplasts, L Forms, Animals, Humans, Bacterial Infections
Abstract

L-forms are "cell wall-deficient" bacteria which are able to grow as spheroplasts or protoplasts. They can be differentiated into four types depending on their ability to revert to the parental, cell-walled form and to the extent of their cell-wall modification. L-forms are significant in modern science because of their contributions to an improved understanding of principal questions and their interactions with eukaryotes. This review particularly focuses on research using stable protoplast-type L-forms which have contributed to a better understanding of the structural and functional organisation of the cytoplasmic membrane and of cell division. These L-forms, which have only a single surrounding bilayer membrane, also represent a unique expression system for production of recombinant proteins. A large proportion of L-form publications concern their putative role in human disease and its therapy, a topic which is discussed briefly. L-forms have also been used to form intracellular associations with plant cells and have been shown to elicit induced disease resistance offering a novel method for plant protection. The recent decline in active research on L-forms is a concern as knowledge and experience, as well as unique L-form strains which have been maintained for decades, are being lost.

Published
2009

12. Chapter 1 Bacterial L‐Forms

Author

E J Allan, C Hoischen, and J Gumpert

Subjects
Genetics, Human disease, medicine.anatomical_structure, biology, Cell division, Cytoplasm, Cell, medicine, Spheroplast, biology.organism_classification, Plant cell, Bacteria, Intracellular
Abstract

L-forms are "cell wall-deficient" bacteria which are able to grow as spheroplasts or protoplasts. They can be differentiated into four types depending on their ability to revert to the parental, cell-walled form and to the extent of their cell-wall modification. L-forms are significant in modern science because of their contributions to an improved understanding of principal questions and their interactions with eukaryotes. This review particularly focuses on research using stable protoplast-type L-forms which have contributed to a better understanding of the structural and functional organisation of the cytoplasmic membrane and of cell division. These L-forms, which have only a single surrounding bilayer membrane, also represent a unique expression system for production of recombinant proteins. A large proportion of L-form publications concern their putative role in human disease and its therapy, a topic which is discussed briefly. L-forms have also been used to form intracellular associations with plant cells and have been shown to elicit induced disease resistance offering a novel method for plant protection. The recent decline in active research on L-forms is a concern as knowledge and experience, as well as unique L-form strains which have been maintained for decades, are being lost.

Published
2009
Full Text
View/download PDF

13. Expression of genes of lipid synthesis and altered lipid composition modulates L-glutamate efflux of Corynebacterium glutamicum

Author

Walter Pfefferle, Bettina Möckel, Lothar Eggeling, K M Nampoothiri, C Hoischen, Hermann Sahm, Karin Krumbach, and B Bathe

Subjects
Molecular Sequence Data, Phospholipid, Glutamic Acid, Biology, Corynebacterium, Applied Microbiology and Biotechnology, Corynebacterium glutamicum, chemistry.chemical_compound, Biosynthesis, Bacterial Proteins, Gene expression, Cloning, Molecular, Phospholipids, chemistry.chemical_classification, Temperature, Lipid metabolism, General Medicine, Gene Expression Regulation, Bacterial, Sequence Analysis, DNA, Lipids, Recombinant Proteins, Amino acid, Acyl carrier protein, chemistry, Biochemistry, Mutation, biology.protein, lipids (amino acids, peptides, and proteins), Efflux, Biotechnology
Abstract

L-Glutamate is made with Corynebacterium glutamicum on a scale of more than 106 tons/year. Nevertheless, formation of this amino acid is enigmatic and there is very limited molecular information available to unravel the apparently complex conditions leading to L-glutamate efflux. Here, we report the isolation and overexpression of the genes involved in lipid synthesis: acp, fadD15, cma, cls, pgsA2, cdsA, gpsA, and plsC, and the inactivation of cma and cls. In addition, the consequences for phospholipid content, temperature sensitivity, as well as detergent-independent and detergent-dependent L-glutamate efflux were quantified. An in part strong alteration of the phospholipid composition was achieved; for instance, overexpression of fadD15 encoding an acyl-CoA ligase resulted in an increase of phosphatidyl inositol from 12.6 to 30.2%. All strains, except that overexpressing acp (acyl carrier protein), exhibited increased temperature sensitivity, with the strongest sensitivity present upon cls (cardiolipin synthetase) inactivation. As a consequence of the genetically modified lipid synthesis, L-glutamate efflux changed quite dramatically; for instance, overexpression of plsC (acylglycerolacyl transferase) resulted in a detergent-triggered increase of L-glutamate accumulation from 92 mM to 108 mM, whereas acp overexpression reduced the accumulation to 24 mM. With some of the overexpressed genes, substantial L-glutamate excretion even without detergent addition was obtained when the fermentation temperature was elevated. These data show that the chemical and physical properties of the cytoplasmic membrane are altered and suggest that this is a necessary precondition to achieve L-glutamate efflux.

Published
2002

14. [Isolation of glutamylendopeptidase precursor from B. licheniformis and its processing in vitro]

Author

A V, Serkina, A M, Bushueva, G G, Chestukhina, J, Gumpert, C, Hoischen, M, Kujau, and A B, Shevelev

Subjects
Enzyme Activation, Enzyme Precursors, Base Sequence, Molecular Sequence Data, Serine Endopeptidases, Bacillus, Oligonucleotide Probes, Protein Processing, Post-Translational, Chromatography, Affinity, Plasmids
Abstract

A secretory system based on L-form cells of Proteus mirabilis was developed for production of native Bacillus licheniformis glutamylendopeptidase precursor never formerly available. The produced precursor was stable per se under physiological conditions and in presence of trypsin and glutamylendopeptidase from B. intermedius. Complete conversion of the precursor to the mature glutamylendopeptidase was performed by bacillar metalloproteases and subtilisin. The artificially processed glutamylendopeptidase was purified by affinity chromatography on bacitracin-sepharose. Native tertiary structure in the purified glutamylendopeptidase was confirmed by demonstrating its activity towards a specific chromogenous peptide substrate.

Published
2001

15. A novel protein kinase that controls carbon catabolite repression in bacteria

Author

C Hoischen, Jörg Stülke, Milton H. Saier, Friedrich Titgemeyer, Ralf Rabus, Carlo Rivolta, Wolfgang Hillen, Dimitri Karamata, and Jonathan Reizer

Subjects
Molecular Sequence Data, Catabolite repression, lac operon, Phosphocarrier protein, Protein Serine-Threonine Kinases, Microbiology, MAP2K7, Adenosine Triphosphate, Allosteric Regulation, Bacterial Proteins, Escherichia coli, Fructosediphosphates, c-Raf, Amino Acid Sequence, Enzyme Inhibitors, Phosphorylation, Protein kinase A, Phosphoenolpyruvate Sugar Phosphotransferase System, Molecular Biology, Protein Kinase Inhibitors, biology, Recombinant Proteins, Fed-batch culture, Enzyme Activation, Biochemistry, biology.protein, Protein Kinases, Sequence Alignment, Sequence Analysis, Genome, Bacterial, Catabolite activator protein, Bacillus subtilis
Abstract

HPr(Ser) kinase is the sensor in a multicomponent phosphorelay system that controls catabolite repression, sugar transport and carbon metabolism in gram-positive bacteria. Unlike most other protein kinases, it recognizes the tertiary structure in its target protein, HPr, a phosphocarrier protein of the bacterial phosphotransferase system and a transcriptional cofactor controlling the phenomenon of catabolite repression. We have identified the gene (ptsK) encoding this serine/threonine protein kinase and characterized the purified protein product. Orthologues of PtsK have been identified only in bacteria. These proteins constitute a novel family unrelated to other previously characterized protein phosphorylating enzymes. The Bacillus subtilis kinase is shown to be allosterically activated by metabolites such as fructose 1,6-bisphosphate and inhibited by inorganic phosphate. In contrast to wild-type B. subtilis, the ptsK mutant is insensitive to transcriptional regulation by catabolite repression. The reported results advance our understanding of phosphorylation-dependent carbon control mechanisms in Gram-positive bacteria.

Published
1998
Full Text
View/download PDF

16. Involvement of the central loop of the lactose permease of Escherichia coli in its allosteric regulation by the glucose-specific enzyme IIA of the phosphoenolpyruvate-dependent phosphotransferase system

Author

Milton H. Saier, S Pitaknarongphorn, J Levin, Jonathan Reizer, and C Hoischen

Subjects
Lactose permease, Monosaccharide Transport Proteins, Allosteric regulation, Molecular Sequence Data, Lactose, Microbiology, Beta-galactoside permease, chemistry.chemical_compound, Allosteric Regulation, Escherichia coli, Point Mutation, Amino Acid Sequence, Melibiose, Phosphoenolpyruvate Sugar Phosphotransferase System, Molecular Biology, Binding Sites, biology, Symporters, Membrane transport protein, Permease, Escherichia coli Proteins, Membrane Transport Proteins, Biological Transport, PEP group translocation, Molecular biology, Mutagenesis, Insertional, chemistry, Biochemistry, biology.protein, bacteria, Phosphoenolpyruvate carboxykinase, Research Article, Protein Binding
Abstract

Allosteric regulation of several sugar transport systems such as those specific for lactose, maltose and melibiose in Escherichia coli (inducer exclusion) is mediated by the glucose-specific enzyme IIA (IIAGlc) of the phosphoenolpyruvate:sugar phosphotransferase system (PTS). Deletion mutations in the cytoplasmic N and C termini of the lactose permease protein, LacY, and replacement of all cysteine residues in LacY with other residues did not prevent IIAGlc-mediated inhibition of lactose uptake, but several point and insertional mutations in the central cytoplasmic loop of this permease abolished transport regulation and IIAGlc binding. The results substantiate the conclusion that regulation of the lactose permease in E. coli by the PTS is mediated by a primary interaction of IIAGlc with the central cytoplasmic loop of the permease.

Published
1996

18. Comparative genomics hints at dispensability of multiple essential genes in two Escherichia coli L-form strains.

Author

Liu Y, Zhang Y, Kang C, Tian D, Lu H, Xu B, Xia Y, Kashiwagi A, Westermann M, Hoischen C, Xu J, and Yomo T

Subjects
Genes, Essential genetics, Genomics, Mutation, Escherichia coli genetics, Escherichia coli metabolism, Escherichia coli Proteins genetics, Escherichia coli Proteins metabolism
Abstract

Despite the critical role of bacterial cell walls in maintaining cell shapes, certain environmental stressors can induce the transition of many bacterial species into a wall-deficient state called L-form. Long-term induced Escherichia coli L-forms lose their rod shape and usually hold significant mutations that affect cell division and growth. Besides this, the genetic background of L-form bacteria is still poorly understood. In the present study, the genomes of two stable L-form strains of E. coli (NC-7 and LWF+) were sequenced and their gene mutation status was determined and compared with their parental strains. Comparative genomic analysis between two L-forms reveals both unique adaptions and common mutated genes, many of which belong to essential gene categories not involved in cell wall biosynthesis, indicating that L-form genetic adaptation impacts crucial metabolic pathways. Missense variants from L-forms and Lenski's long-term evolution experiment (LTEE) were analyzed in parallel using an optimized DeepSequence pipeline to investigate predicted mutation effects (α) on protein functions. We report that the two L-form strains analyzed display a frequency of 6-10% (0% for LTEE) in mutated essential genes where the missense variants have substantial impact on protein functions (α<0.5). This indicates the emergence of different survival strategies in L-forms through changes in essential genes during adaptions to cell wall deficiency. Collectively, our results shed light on the detailed genetic background of two E. coli L-forms and pave the way for further investigations of the gene functions in L-form bacterial models., (© 2023 The Author(s).)

Published
2023
Full Text
View/download PDF

19. Light and prey influence the abundances of two rhodopsins in the dinoflagellate Oxyrrhis marina.

Author

Westermann M, Hoischen C, Wöhlbrand L, Rabus R, and Rhiel E

Subjects
Cell Membrane, Dinoflagellida chemistry, Rhodopsin metabolism
Abstract

Antisera were raised against the C-terminal amino acid sequences of the two rhodopsins ADY17806 and AEA49880 of Oxyrrhis marina. The antisera and affinity-purified antibodies thereof were used in western immunoblotting experiments of total cell protein fractions from cultures grown either in darkness or in white, red, green, or blue light. Furthermore, the rhodopsin abundances were profiled in cultures fed with yeast or the prasinophyte Pyramimonas grossii. The immunosignals of ADY17806 and AEA49880 were similar when O. marina was grown in white, green, or blue light. Signal intensities were lower under conditions of red light and lowest in darkness. Higher amounts were registered for both rhodopsins when O. marina was fed with yeast compared to P. grossii. Furthermore, total cell protein of cultures of O. marina grown under all cultivation conditions was separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, followed by tryptic in-gel digestion and mass spectrometric analysis of the 25-kDa protein bands. The rhodopsin ADY17809 was detected in all samples of the light quality experiments and in 14 of the 16 samples of the prey quality experiments. The rhodopsin ABV22427 was not detected in one sample of the light quality experiments. It was detected in 15 of the 16 samples of the prey quality experiments. Peptide fragments of the other rhodopsins were detected less often, and no clear distribution pattern was evident with respect to the applied light quality or offered prey, indicating that none of them was exclusively formed under a distinct light regime or when feeding on yeast or the prasinophyte. Fluorescence light microscopy using the affinity-purified antibodies revealed significant labeling of the cell periphery and cell internal structures, which resembled vacuoles, tiny vesicles, and rather compact structures. Immunolabeling electron microscopy strengthened these results and showed that the cytoplasmic membrane, putative lysosome membranes, membranes encircling the food vacuole, and birefringent bodies became labeled., (© 2022. The Author(s).)

Published
2023
Full Text
View/download PDF

20. Rhodopsins build up the birefringent bodies of the dinoflagellate Oxyrrhis marina.

Author

Rhiel E, Hoischen C, and Westermann M

Subjects
Microscopy, Electron, Transmission, Rhodopsin metabolism, Dinoflagellida chemistry
Abstract

The ultrastructure of the birefringent bodies of the dinoflagellate Oxyrrhis marina was investigated by transmission electron microscopy. Ultrathin sectioning revealed that the bodies consist of highly ordered and densely packed lamellae, which show a regular striation along their longitudinal axis. A lattice distance of 6.1 nm was measured for the densely packed lamellae by FFT (Fast Fourier Transformation) analysis. In addition, a rather faint and oblique running striation was registered. Lamellae sectioned rather oblique or almost close to the surface show a honeycombed structure with a periodicity of 7.2-7.8 nm. Freeze-fracture transmission electron microscopy revealed that the lamellae are composed of highly ordered, crystalline arrays of particles. Here, FFT analysis resulted in lattice distances of 7.0-7.6 nm. Freeze-fracture transmission electron microscopy further revealed that the bodies remained intact after cell rupture followed by ascending flotation of the membrane fractions on discontinuous sucrose gradients. The birefringent bodies most likely are formed by evaginations of membranes, which separate the cytoplasm from the food vacuoles. Distinct, slightly reddish-colored areas, which resembled the birefringent bodies with respect to size and morphology, were registered by bright field light microscopy within Oxyrrhis marina cells. An absorbance maximum at 540 nm was registered for these areas, indicating that they are composed of rhodopsins. This was finally proven by immuno-transmission electron microscopy, as antisera directed against the C-terminal amino acid sequences of the rhodopsins AEA49880 and ADY17806 intensely immunolabeled the birefringent bodies of Oxyrrhis marina., (© 2021. The Author(s).)

Published
2022
Full Text
View/download PDF

21. Time-resolved hadronic particle acceleration in the recurrent nova RS Ophiuchi.

Author

Aharonian F, Ait Benkhali F, Angüner EO, Ashkar H, Backes M, Baghmanyan V, Barbosa Martins V, Batzofin R, Becherini Y, Berge D, Bernlöhr K, Bi B, Böttcher M, Boisson C, Bolmont J, de Bony de Lavergne M, Breuhaus M, Brose R, Brun F, Caroff S, Casanova S, Cerruti M, Chand T, Chen A, Cotter G, Damascene Mbarubucyeye J, Djannati-Ataï A, Dmytriiev A, Doroshenko V, Duffy C, Egberts K, Ernenwein JP, Fegan S, Feijen K, Fiasson A, Fichet de Clairfontaine G, Fontaine G, Füßling M, Funk S, Gabici S, Gallant YA, Ghafourizadeh S, Giavitto G, Giunti L, Glawion D, Glicenstein JF, Grondin MH, Hermann G, Hinton JA, Hörbe M, Hofmann W, Hoischen C, Holch TL, Holler M, Horns D, Huang Z, Jamrozy M, Jankowsky F, Jung-Richardt I, Kasai E, Katarzyński K, Katz U, Khangulyan D, Khélifi B, Klepser S, Kluźniak W, Komin N, Konno R, Kosack K, Kostunin D, Le Stum S, Lemière A, Lemoine-Goumard M, Lenain JP, Leuschner F, Lohse T, Luashvili A, Lypova I, Mackey J, Malyshev D, Malyshev D, Marandon V, Marchegiani P, Marcowith A, Martí-Devesa G, Marx R, Maurin G, Meyer M, Mitchell A, Moderski R, Mohrmann L, Montanari A, Moulin E, Muller J, Murach T, Nakashima K, de Naurois M, Nayerhoda A, Niemiec J, Priyana Noel A, O'Brien P, Ohm S, Olivera-Nieto L, de Ona Wilhelmi E, Ostrowski M, Panny S, Panter M, Parsons RD, Peron G, Pita S, Poireau V, Prokhorov DA, Prokoph H, Pühlhofer G, Punch M, Quirrenbach A, Reichherzer P, Reimer A, Reimer O, Renaud M, Reville B, Rieger F, Rowell G, Rudak B, Rueda Ricarte H, Ruiz-Velasco E, Sahakian V, Sailer S, Salzmann H, Sanchez DA, Santangelo A, Sasaki M, Schäfer J, Schüssler F, Schutte HM, Schwanke U, Senniappan M, Shapopi JNS, Simoni R, Sinha A, Sol H, Specovius A, Spencer S, Stawarz Ł, Steinmassl S, Steppa C, Takahashi T, Tanaka T, Taylor AM, Terrier R, Thorpe-Morgan C, Tsirou M, Tsuji N, Tuffs R, Uchiyama Y, Unbehaun T, van Eldik C, van Soelen B, Veh J, Venter C, Vink J, Wagner SJ, Werner F, White R, Wierzcholska A, Wong YW, Yusafzai A, Zacharias M, Zargaryan D, Zdziarski AA, Zech A, Zhu SJ, Zouari S, and Żywucka N

Abstract

Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material slams into the companion star's wind can accelerate particles. We report very-high-energy (VHE; [Formula: see text]) gamma rays from the recurrent nova RS Ophiuchi, up to 1 month after its 2021 outburst, observed using the High Energy Stereoscopic System (H.E.S.S.). The temporal profile of VHE emission is similar to that of lower-energy giga-electron volt emission, indicating a common origin, with a 2-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic rays to very high energies.

Published
2022
Full Text
View/download PDF

23. Disease-causing mutated ATLASTIN 3 is excluded from distal axons and reduces axonal autophagy.

Author

Behrendt L, Hoischen C, and Kaether C

Subjects
Animals, Axons pathology, Cells, Cultured, HEK293 Cells, HeLa Cells, Humans, Mice, Mice, 129 Strain, Mice, Inbred C57BL, Autophagy physiology, Axons physiology, GTP Phosphohydrolases genetics, GTP Phosphohydrolases metabolism, Mutation physiology
Abstract

Mutations in the ER-network forming GTPase atlastin3 (ATL3) can cause axon degeneration of sensory neurons by not fully understood mechanisms. We here show that the hereditary sensory and autonomous neuropathy (HSAN)-causing ATL3 Y192C or P338R are excluded from distal axons by a barrier at the axon initial segment (AIS). This barrier is selective for mutated ATL3, but not wildtype ATL3 or unrelated ER-membrane proteins. Actin-depolymerization partially restores the transport of ATL3 Y192C into distal axons. The results point to the existence of a selective diffusion barrier in the ER membrane at the AIS, analogous to the AIS-based barriers for plasma membrane and cytosolic proteins. Functionally, the absence of ATL3 at the distal axon reduces axonal autophagy and the ER network deformation in the soma causes a reduction in axonal lysosomes. Both could contribute to axonal degeneration and eventually to HSAN., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Published
2021
Full Text
View/download PDF

24. Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow.

Author

Abdalla H, Aharonian F, Ait Benkhali F, Angüner EO, Arcaro C, Armand C, Armstrong T, Ashkar H, Backes M, Baghmanyan V, Barbosa Martins V, Barnacka A, Barnard M, Becherini Y, Berge D, Bernlöhr K, Bi B, Bissaldi E, Böttcher M, Boisson C, Bolmont J, de Bony de Lavergne M, Breuhaus M, Brun F, Brun P, Bryan M, Büchele M, Bulik T, Bylund T, Caroff S, Carosi A, Casanova S, Chand T, Chandra S, Chen A, Cotter G, Curyło M, Damascene Mbarubucyeye J, Davids ID, Davies J, Deil C, Devin J, Dirson L, Djannati-Ataï A, Dmytriiev A, Donath A, Doroshenko V, Dreyer L, Duffy C, Dyks J, Egberts K, Eichhorn F, Einecke S, Emery G, Ernenwein JP, Feijen K, Fegan S, Fiasson A, Fichet de Clairfontaine G, Fontaine G, Funk S, Füßling M, Gabici S, Gallant YA, Giavitto G, Giunti L, Glawion D, Glicenstein JF, Grondin MH, Hahn J, Haupt M, Hermann G, Hinton JA, Hofmann W, Hoischen C, Holch TL, Holler M, Hörbe M, Horns D, Huber D, Jamrozy M, Jankowsky D, Jankowsky F, Jardin-Blicq A, Joshi V, Jung-Richardt I, Kasai E, Kastendieck MA, Katarzyński K, Katz U, Khangulyan D, Khélifi B, Klepser S, Kluźniak W, Komin N, Konno R, Kosack K, Kostunin D, Kreter M, Lamanna G, Lemière A, Lemoine-Goumard M, Lenain JP, Leuschner F, Levy C, Lohse T, Lypova I, Mackey J, Majumdar J, Malyshev D, Malyshev D, Marandon V, Marchegiani P, Marcowith A, Mares A, Martí-Devesa G, Marx R, Maurin G, Meintjes PJ, Meyer M, Mitchell A, Moderski R, Mohrmann L, Montanari A, Moore C, Morris P, Moulin E, Muller J, Murach T, Nakashima K, Nayerhoda A, de Naurois M, Ndiyavala H, Niemiec J, Oakes L, O'Brien P, Odaka H, Ohm S, Olivera-Nieto L, de Ona Wilhelmi E, Ostrowski M, Panny S, Panter M, Parsons RD, Peron G, Peyaud B, Piel Q, Pita S, Poireau V, Priyana Noel A, Prokhorov DA, Prokoph H, Pühlhofer G, Punch M, Quirrenbach A, Raab S, Rauth R, Reichherzer P, Reimer A, Reimer O, Remy Q, Renaud M, Rieger F, Rinchiuso L, Romoli C, Rowell G, Rudak B, Ruiz-Velasco E, Sahakian V, Sailer S, Salzmann H, Sanchez DA, Santangelo A, Sasaki M, Scalici M, Schäfer J, Schüssler F, Schutte HM, Schwanke U, Seglar-Arroyo M, Senniappan M, Seyffert AS, Shafi N, Shapopi JNS, Shiningayamwe K, Simoni R, Sinha A, Sol H, Specovius A, Spencer S, Spir-Jacob M, Stawarz Ł, Sun L, Steenkamp R, Stegmann C, Steinmassl S, Steppa C, Takahashi T, Tam T, Tavernier T, Taylor AM, Terrier R, Thiersen JHE, Tiziani D, Tluczykont M, Tomankova L, Tsirou M, Tuffs R, Uchiyama Y, van der Walt DJ, van Eldik C, van Rensburg C, van Soelen B, Vasileiadis G, Veh J, Venter C, Vincent P, Vink J, Völk HJ, Wadiasingh Z, Wagner SJ, Watson J, Werner F, White R, Wierzcholska A, Wong YW, Yusafzai A, Zacharias M, Zanin R, Zargaryan D, Zdziarski AA, Zech A, Zhu SJ, Zorn J, Zouari S, Żywucka N, Evans P, and Page K

Abstract

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Published
2021
Full Text
View/download PDF

25. The proteorhodopsins of the dinoflagellate Oxyrrhis marina: ultrastructure and localization by immunofluorescence light microscopy and immunoelectron microscopy.

Author

Rhiel E, Westermann M, Steiniger F, and Hoischen C

Subjects
Dinoflagellida chemistry, Dinoflagellida ultrastructure, Microscopy, Electron, Transmission methods, Microscopy, Fluorescence methods, Rhodopsins, Microbial chemistry, Rhodopsins, Microbial ultrastructure
Abstract

At least 7 proteorhodopsin sequences of Oxyrrhis marina were recently proven in bands obtained by sucrose density gradient centrifugation, and MS analyses revealed that the bands consisted almost of pure, native proteorhodopsins (Rhiel et al. 2020). The proteorhodopsin fractions, i.e., bands B2, B3, and B4 were subjected to transmission electron microscopy. Negative staining revealed that band B2 consisted most likely of monomeric/oligomeric proteorhodopsins with particle dimensions of about 6 nm. Negative staining, freeze-fracture, and cryo-transmission electron microscopy revealed that bands B3 and B4 consisted of vesicular, sheet-like, and cup-shaped structures which all seemed to be composed of protein. Frequently, ring-like protein aggregates were registered at higher magnifications. They measured about 4 nm in diameter with a tiny hole of 1.5 nm in the middle. The bands B2, B3, and B4 were pooled and used to raise an antiserum. Immunoelectron microscopy resulted in intense labeling of the isolated structures. Immunofluorescence light microscopy of formaldehyde-fixed Oxyrrhis cells resulted in intense labeling of the cell periphery. Some cell internal structures became labeled, too. Immunoelectron microscopy of freeze-fractured cells revealed that most likely the membranes of the amphiesmal vesicles were labeled at the cell periphery, while the cell internal label seemed to originate from the food vacuoles.

Published
2020
Full Text
View/download PDF

26. Comparison of Multiscale Imaging Methods for Brain Research.

Author

Tröger J, Hoischen C, Perner B, Monajembashi S, Barbotin A, Löschberger A, Eggeling C, Kessels MM, Qualmann B, and Hemmerich P

Subjects
Animals, Male, Mice, Microscopy, Confocal, Neurons cytology, Rats, Single-Cell Analysis, Synapses physiology, Brain anatomy & histology, Imaging, Three-Dimensional, Research
Abstract

A major challenge in neuroscience is how to study structural alterations in the brain. Even small changes in synaptic composition could have severe outcomes for body functions. Many neuropathological diseases are attributable to disorganization of particular synaptic proteins. Yet, to detect and comprehensively describe and evaluate such often rather subtle deviations from the normal physiological status in a detailed and quantitative manner is very challenging. Here, we have compared side-by-side several commercially available light microscopes for their suitability in visualizing synaptic components in larger parts of the brain at low resolution, at extended resolution as well as at super-resolution. Microscopic technologies included stereo, widefield, deconvolution, confocal, and super-resolution set-ups. We also analyzed the impact of adaptive optics, a motorized objective correction collar and CUDA graphics card technology on imaging quality and acquisition speed. Our observations evaluate a basic set of techniques, which allow for multi-color brain imaging from centimeter to nanometer scales. The comparative multi-modal strategy we established can be used as a guide for researchers to select the most appropriate light microscopy method in addressing specific questions in brain research, and we also give insights into recent developments such as optical aberration corrections.

Published
2020
Full Text
View/download PDF

27. Aneuploidy-inducing gene knockdowns overlap with cancer mutations and identify Orp3 as a B-cell lymphoma suppressor.

Author

Njeru SN, Kraus J, Meena JK, Lechel A, Katz SF, Kumar M, Knippschild U, Azoitei A, Wezel F, Bolenz C, Leithäuser F, Gollowitzer A, Omrani O, Hoischen C, Koeberle A, Kestler HA, Günes C, and Rudolph KL

Subjects
Animals, Cell Line, Tumor, Cell Transformation, Neoplastic, Fibroblasts pathology, Humans, Lymphoma, B-Cell pathology, Mice, Aneuploidy, Fatty Acid-Binding Proteins deficiency, Fatty Acid-Binding Proteins genetics, Gene Knockdown Techniques, Lymphoma, B-Cell genetics
Abstract

Aneuploidy can instigate tumorigenesis. However, mutations in genes that control chromosome segregation are rare in human tumors as these mutations reduce cell fitness. Screening experiments indicate that the knockdown of multiple classes of genes that are not directly involved in chromosome segregation can lead to aneuploidy induction. The possible contribution of these genes to cancer formation remains yet to be defined. Here we identified gene knockdowns that lead to an increase in aneuploidy in checkpoint-deficient human cancer cells. Computational analysis revealed that the identified genes overlap with recurrent mutations in human cancers. The knockdown of the three strongest selected candidate genes (ORP3, GJB3, and RXFP1) enhances the malignant transformation of human fibroblasts in culture. Furthermore, the knockout of Orp3 results in an aberrant expansion of lymphoid progenitor cells and a high penetrance formation of chromosomal instable, pauci-clonal B-cell lymphoma in aging mice. At pre-tumorous stages, lymphoid cells from the animals exhibit deregulated phospholipid metabolism and an aberrant induction of proliferation regulating pathways associating with increased aneuploidy in hematopoietic progenitor cells. Together, these results support the concept that aneuploidy-inducing gene deficiencies contribute to cellular transformation and carcinogenesis involving the deregulation of various molecular processes such as lipid metabolism, proliferation, and cell survival.

Published
2020
Full Text
View/download PDF

28. A very-high-energy component deep in the γ-ray burst afterglow.

Author

Abdalla H, Adam R, Aharonian F, Ait Benkhali F, Angüner EO, Arakawa M, Arcaro C, Armand C, Ashkar H, Backes M, Barbosa Martins V, Barnard M, Becherini Y, Berge D, Bernlöhr K, Bissaldi E, Blackwell R, Böttcher M, Boisson C, Bolmont J, Bonnefoy S, Bregeon J, Breuhaus M, Brun F, Brun P, Bryan M, Büchele M, Bulik T, Bylund T, Capasso M, Caroff S, Carosi A, Casanova S, Cerruti M, Chand T, Chandra S, Chen A, Colafrancesco S, Curyło M, Davids ID, Deil C, Devin J, deWilt P, Dirson L, Djannati-Ataï A, Dmytriiev A, Donath A, Doroshenko V, Dyks J, Egberts K, Emery G, Ernenwein JP, Eschbach S, Feijen K, Fegan S, Fiasson A, Fontaine G, Funk S, Füßling M, Gabici S, Gallant YA, Gaté F, Giavitto G, Giunti L, Glawion D, Glicenstein JF, Gottschall D, Grondin MH, Hahn J, Haupt M, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hofmann W, Hoischen C, Holch TL, Holler M, Horns D, Huber D, Iwasaki H, Jamrozy M, Jankowsky D, Jankowsky F, Jardin-Blicq A, Jung-Richardt I, Kastendieck MA, Katarzyński K, Katsuragawa M, Katz U, Khangulyan D, Khélifi B, King J, Klepser S, Kluźniak W, Komin N, Kosack K, Kostunin D, Kreter M, Lamanna G, Lemière A, Lemoine-Goumard M, Lenain JP, Leser E, Levy C, Lohse T, Lypova I, Mackey J, Majumdar J, Malyshev D, Marandon V, Marcowith A, Mares A, Mariaud C, Martí-Devesa G, Marx R, Maurin G, Meintjes PJ, Mitchell AMW, Moderski R, Mohamed M, Mohrmann L, Moore C, Moulin E, Muller J, Murach T, Nakashima S, de Naurois M, Ndiyavala H, Niederwanger F, Niemiec J, Oakes L, O'Brien P, Odaka H, Ohm S, de Ona Wilhelmi E, Ostrowski M, Oya I, Panter M, Parsons RD, Perennes C, Petrucci PO, Peyaud B, Piel Q, Pita S, Poireau V, Priyana Noel A, Prokhorov DA, Prokoph H, Pühlhofer G, Punch M, Quirrenbach A, Raab S, Rauth R, Reimer A, Reimer O, Remy Q, Renaud M, Rieger F, Rinchiuso L, Romoli C, Rowell G, Rudak B, Ruiz-Velasco E, Sahakian V, Sailer S, Saito S, Sanchez DA, Santangelo A, Sasaki M, Schlickeiser R, Schüssler F, Schulz A, Schutte HM, Schwanke U, Schwemmer S, Seglar-Arroyo M, Senniappan M, Seyffert AS, Shafi N, Shiningayamwe K, Simoni R, Sinha A, Sol H, Specovius A, Spir-Jacob M, Stawarz Ł, Steenkamp R, Stegmann C, Steppa C, Takahashi T, Tavernier T, Taylor AM, Terrier R, Tiziani D, Tluczykont M, Trichard C, Tsirou M, Tsuji N, Tuffs R, Uchiyama Y, van der Walt DJ, van Eldik C, van Rensburg C, van Soelen B, Vasileiadis G, Veh J, Venter C, Vincent P, Vink J, Völk HJ, Vuillaume T, Wadiasingh Z, Wagner SJ, White R, Wierzcholska A, Yang R, Yoneda H, Zacharias M, Zanin R, Zdziarski AA, Zech A, Ziegler A, Zorn J, Żywucka N, de Palma F, Axelsson M, and Roberts OJ

Abstract

Gamma-ray bursts (GRBs) are brief flashes of γ-rays and are considered to be the most energetic explosive phenomena in the Universe 1 . The emission from GRBs comprises a short (typically tens of seconds) and bright prompt emission, followed by a much longer afterglow phase. During the afterglow phase, the shocked outflow-produced by the interaction between the ejected matter and the circumburst medium-slows down, and a gradual decrease in brightness is observed 2 . GRBs typically emit most of their energy via γ-rays with energies in the kiloelectronvolt-to-megaelectronvolt range, but a few photons with energies of tens of gigaelectronvolts have been detected by space-based instruments 3 . However, the origins of such high-energy (above one gigaelectronvolt) photons and the presence of very-high-energy (more than 100 gigaelectronvolts) emission have remained elusive 4 . Here we report observations of very-high-energy emission in the bright GRB 180720B deep in the GRB afterglow-ten hours after the end of the prompt emission phase, when the X-ray flux had already decayed by four orders of magnitude. Two possible explanations exist for the observed radiation: inverse Compton emission and synchrotron emission of ultrarelativistic electrons. Our observations show that the energy fluxes in the X-ray and γ-ray range and their photon indices remain comparable to each other throughout the afterglow. This discovery places distinct constraints on the GRB environment for both emission mechanisms, with the inverse Compton explanation alleviating the particle energy requirements for the emission observed at late times. The late timing of this detection has consequences for the future observations of GRBs at the highest energies.

Published
2019
Full Text
View/download PDF

29. Multimodal Light Microscopy Approaches to Reveal Structural and Functional Properties of Promyelocytic Leukemia Nuclear Bodies.

Author

Hoischen C, Monajembashi S, Weisshart K, and Hemmerich P

Abstract

The promyelocytic leukemia ( pml ) gene product PML is a tumor suppressor localized mainly in the nucleus of mammalian cells. In the cell nucleus, PML seeds the formation of macromolecular multiprotein complexes, known as PML nuclear bodies (PML NBs). While PML NBs have been implicated in many cellular functions including cell cycle regulation, survival and apoptosis their role as signaling hubs along major genome maintenance pathways emerged more clearly. However, despite extensive research over the past decades, the precise biochemical function of PML in these pathways is still elusive. It remains a big challenge to unify all the different previously suggested cellular functions of PML NBs into one mechanistic model. With the advent of genetically encoded fluorescent proteins it became possible to trace protein function in living specimens. In parallel, a variety of fluorescence fluctuation microscopy (FFM) approaches have been developed which allow precise determination of the biophysical and interaction properties of cellular factors at the single molecule level in living cells. In this report, we summarize the current knowledge on PML nuclear bodies and describe several fluorescence imaging, manipulation, FFM, and super-resolution techniques suitable to analyze PML body assembly and function. These include fluorescence redistribution after photobleaching, fluorescence resonance energy transfer, fluorescence correlation spectroscopy, raster image correlation spectroscopy, ultraviolet laser microbeam-induced DNA damage, erythrocyte-mediated force application, and super-resolution microscopy approaches. Since most if not all of the microscopic equipment to perform these techniques may be available in an institutional or nearby facility, we hope to encourage more researches to exploit sophisticated imaging tools for their research in cancer biology.

Published
2018
Full Text
View/download PDF

30. Search for γ-Ray Line Signals from Dark Matter Annihilations in the Inner Galactic Halo from 10 Years of Observations with H.E.S.S.

Author

Abdallah H, Abramowski A, Aharonian F, Ait Benkhali F, Angüner EO, Arakawa M, Arrieta M, Aubert P, Backes M, Balzer A, Barnard M, Becherini Y, Becker Tjus J, Berge D, Bernhard S, Bernlöhr K, Blackwell R, Böttcher M, Boisson C, Bolmont J, Bonnefoy S, Bordas P, Bregeon J, Brun F, Brun P, Bryan M, Büchele M, Bulik T, Capasso M, Caroff S, Carosi A, Carr J, Casanova S, Cerruti M, Chakraborty N, Chaves RCG, Chen A, Chevalier J, Colafrancesco S, Condon B, Conrad J, Davids ID, Decock J, Deil C, Devin J, deWilt P, Dirson L, Djannati-Ataï A, Domainko W, Donath A, Drury LO, Dutson K, Dyks J, Edwards T, Egberts K, Eger P, Emery G, Ernenwein JP, Eschbach S, Farnier C, Fegan S, Fernandes MV, Fiasson A, Fontaine G, Förster A, Funk S, Füßling M, Gabici S, Gallant YA, Garrigoux T, Gaté F, Giavitto G, Giebels B, Glawion D, Glicenstein JF, Gottschall D, Grondin MH, Hahn J, Haupt M, Hawkes J, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hofmann W, Hoischen C, Holch TL, Holler M, Horns D, Ivascenko A, Iwasaki H, Jacholkowska A, Jamrozy M, Janiak M, Jankowsky D, Jankowsky F, Jingo M, Jouvin L, Jung-Richardt I, Kastendieck MA, Katarzyński K, Katsuragawa M, Katz U, Kerszberg D, Khangulyan D, Khélifi B, King J, Klepser S, Klochkov D, Kluźniak W, Komin N, Kosack K, Krakau S, Kraus M, Krüger PP, Laffon H, Lamanna G, Lau J, Lees JP, Lefaucheur J, Lemière A, Lemoine-Goumard M, Lenain JP, Leser E, Liu R, Lohse T, Lorentz M, López-Coto R, Lypova I, Malyshev D, Marandon V, Marcowith A, Mariaud C, Marx R, Maurin G, Maxted N, Mayer M, Meintjes PJ, Meyer M, Mitchell AMW, Moderski R, Mohamed M, Mohrmann L, Morå K, Moulin E, Murach T, Nakashima S, de Naurois M, Ndiyavala H, Niederwanger F, Niemiec J, Oakes L, O'Brien P, Odaka H, Ohm S, Ostrowski M, Oya I, Padovani M, Panter M, Parsons RD, Pekeur NW, Pelletier G, Perennes C, Petrucci PO, Peyaud B, Piel Q, Pita S, Poireau V, Poon H, Prokhorov D, Prokoph H, Pühlhofer G, Punch M, Quirrenbach A, Raab S, Rauth R, Reimer A, Reimer O, Renaud M, de Los Reyes R, Rieger F, Rinchiuso L, Romoli C, Rowell G, Rudak B, Rulten CB, Sahakian V, Saito S, Sanchez DA, Santangelo A, Sasaki M, Schandri M, Schlickeiser R, Schüssler F, Schulz A, Schwanke U, Schwemmer S, Seglar-Arroyo M, Settimo M, Seyffert AS, Shafi N, Shilon I, Shiningayamwe K, Simoni R, Sol H, Spanier F, Spir-Jacob M, Stawarz Ł, Steenkamp R, Stegmann C, Steppa C, Sushch I, Takahashi T, Tavernet JP, Tavernier T, Taylor AM, Terrier R, Tibaldo L, Tiziani D, Tluczykont M, Trichard C, Tsirou M, Tsuji N, Tuffs R, Uchiyama Y, van der Walt J, van Eldik C, van Rensburg C, van Soelen B, Vasileiadis G, Veh J, Venter C, Viana A, Vincent P, Vink J, Voisin F, Völk HJ, Vuillaume T, Wadiasingh Z, Wagner SJ, Wagner P, Wagner RM, White R, Wierzcholska A, Willmann P, Wörnlein A, Wouters D, Yang R, Zaborov D, Zacharias M, Zanin R, Zdziarski AA, Zech A, Zefi F, Ziegler A, Zorn J, and Żywucka N

Abstract

Spectral lines are among the most powerful signatures for dark matter (DM) annihilation searches in very-high-energy γ rays. The central region of the Milky Way halo is one of the most promising targets given its large amount of DM and proximity to Earth. We report on a search for a monoenergetic spectral line from self-annihilations of DM particles in the energy range from 300 GeV to 70 TeV using a two-dimensional maximum likelihood method taking advantage of both the spectral and spatial features of the signal versus background. The analysis makes use of Galactic center observations accumulated over ten years (2004-2014) with the H.E.S.S. array of ground-based Cherenkov telescopes. No significant γ-ray excess above the background is found. We derive upper limits on the annihilation cross section ⟨σv⟩ for monoenergetic DM lines at the level of 4×10^{-28}  cm^{3} s^{-1} at 1 TeV, assuming an Einasto DM profile for the Milky Way halo. For a DM mass of 1 TeV, they improve over the previous ones by a factor of 6. The present constraints are the strongest obtained so far for DM particles in the mass range 300 GeV-70 TeV. Ground-based γ-ray observations have reached sufficient sensitivity to explore relevant velocity-averaged cross sections for DM annihilation into two γ-ray photons at the level expected from the thermal relic density for TeV DM particles.

Published
2018
Full Text
View/download PDF

31. CENP-C/H/I/K/M/T/W/N/L and hMis12 but not CENP-S/X participate in complex formation in the nucleoplasm of living human interphase cells outside centromeres.

Author

Hoischen C, Yavas S, Wohland T, and Diekmann S

Subjects
Apoptosis Regulatory Proteins genetics, Apoptosis Regulatory Proteins metabolism, Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Cell Line, Tumor, Centromere genetics, Chromosomal Proteins, Non-Histone genetics, Chromosomal Proteins, Non-Histone metabolism, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Humans, Microtubule-Associated Proteins genetics, Microtubule-Associated Proteins metabolism, Neoplasm Proteins genetics, Neoplasms genetics, Neoplasms pathology, Nuclear Proteins genetics, Nuclear Proteins metabolism, Tumor Suppressor Proteins genetics, Tumor Suppressor Proteins metabolism, Centromere metabolism, Interphase, Neoplasm Proteins metabolism, Neoplasms metabolism
Abstract

Kinetochore proteins assemble onto centromeric chromatin and regulate DNA segregation during cell division. The inner kinetochore proteins bind centromeres while most outer kinetochore proteins assemble at centromeres during mitosis, connecting the complex to microtubules. Here, we measured the co-migration between protein pairs of the constitutive centromere associated network (CCAN) and hMis12 complexes by fluorescence cross-correlation spectroscopy (FCCS) in the nucleoplasm outside centromeres in living human interphase cells. FCCS is a method that can tell if in living cells two differently fluorescently labelled molecules migrate independently, or co-migrate and thus are part of one and the same soluble complex. We also determined the apparent dissociation constants (Kd) of the hetero-dimers CENP-T/W and CENP-S/X. We measured co-migration between CENP-K and CENP-T as well as between CENP-M and CENP-T but not between CENP-T/W and CENP-S/X. Furthermore, CENP-C co-migrated with CENP-H, and CENP-K with CENP-N as well as with CENP-L. Thus, in the nucleoplasm outside centromeres, a large fraction of the CENP-H/I/K/M proteins interact with CENP-C, CENP-N/L and CENP-T/W but not with CENP-S/X. Our FCCS analysis of the Mis12 complex showed that hMis12, Nsl1, Dsn1 and Nnf1 also form a complex outside centromeres of which at least hMis12 associated with the CENP-C/H/I/K/M/T/W/N/L complex.

Published
2018
Full Text
View/download PDF

32. Inhibition of cargo export at ER exit sites and the trans-Golgi network by the secretion inhibitor FLI-06.

Author

Yonemura Y, Li X, Müller K, Krämer A, Atigbire P, Mentrup T, Feuerhake T, Kroll T, Shomron O, Nohl R, Arndt HD, Hoischen C, Hemmerich P, Hirschberg K, and Kaether C

Subjects
Autophagosomes drug effects, Autophagosomes metabolism, Endocytosis drug effects, Exocytosis drug effects, HeLa Cells, Humans, Peroxisomes drug effects, Peroxisomes metabolism, Protein Folding drug effects, Protein Transport drug effects, trans-Golgi Network drug effects, Endoplasmic Reticulum metabolism, Quinolines pharmacology, trans-Golgi Network metabolism
Abstract

Export out of the endoplasmic reticulum (ER) involves the Sar1 and COPII machinery acting at ER exit sites (ERES). Whether and how cargo proteins are recruited upstream of Sar1 and COPII is unclear. Two models are conceivable, a recruitment model where cargo is actively transported through a transport factor and handed over to the Sar1 and COPII machinery in ERES, and a capture model, where cargo freely diffuses into ERES where it is captured by the Sar1 and COPII machinery. Using the novel secretion inhibitor FLI-06, we show that recruitment of the cargo VSVG to ERES is an active process upstream of Sar1 and COPII. Applying FLI-06 before concentration of VSVG in ERES completely abolishes its recruitment. In contrast, applying FLI-06 after VSVG concentration in ERES does not lead to dispersal of the concentrated VSVG, arguing that it inhibits recruitment to ERES as opposed to capture in ERES. FLI-06 also inhibits export out of the trans-Golgi network (TGN), suggesting that similar mechanisms might orchestrate cargo selection and concentration at the ER and TGN. FLI-06 does not inhibit autophagosome biogenesis and the ER-peroxisomal transport route, suggesting that these rely on different mechanisms., (© 2016. Published by The Company of Biologists Ltd.)

Published
2016
Full Text
View/download PDF

33. H.E.S.S. Limits on Linelike Dark Matter Signatures in the 100 GeV to 2 TeV Energy Range Close to the Galactic Center.

Author

Abdalla H, Abramowski A, Aharonian F, Ait Benkhali F, Akhperjanian AG, Andersson T, Angüner EO, Arrieta M, Aubert P, Backes M, Balzer A, Barnard M, Becherini Y, Becker Tjus J, Berge D, Bernhard S, Bernlöhr K, Birsin E, Blackwell R, Böttcher M, Boisson C, Bolmont J, Bordas P, Bregeon J, Brun F, Brun P, Bryan M, Bulik T, Capasso M, Carr J, Casanova S, Chakraborty N, Chalme-Calvet R, Chaves RC, Chen A, Chevalier J, Chrétien M, Colafrancesco S, Cologna G, Condon B, Conrad J, Couturier C, Cui Y, Davids ID, Degrange B, Deil C, Devin J, deWilt P, Djannati-Ataï A, Domainko W, Donath A, Drury LO, Dubus G, Dutson K, Dyks J, Dyrda M, Edwards T, Egberts K, Eger P, Ernenwein JP, Eschbach S, Farnier C, Fegan S, Fernandes MV, Fiasson A, Fontaine G, Förster A, Funk S, Füßling M, Gabici S, Gajdus M, Gallant YA, Garrigoux T, Giavitto G, Giebels B, Glicenstein JF, Gottschall D, Goyal A, Grondin MH, Grudzińska M, Hadasch D, Hahn J, Hawkes J, Heinzelmann G, Henri G, Hermann G, Hervet O, Hillert A, Hinton JA, Hofmann W, Hoischen C, Holler M, Horns D, Ivascenko A, Jacholkowska A, Jamrozy M, Janiak M, Jankowsky D, Jankowsky F, Jingo M, Jogler T, Jouvin L, Jung-Richardt I, Kastendieck MA, Katarzyński K, Katz U, Kerszberg D, Khélifi B, Kieffer M, King J, Klepser S, Klochkov D, Kluźniak W, Kolitzus D, Komin N, Kosack K, Krakau S, Kraus M, Krayzel F, Krüger PP, Laffon H, Lamanna G, Lau J, Lees JP, Lefaucheur J, Lefranc V, Lemière A, Lemoine-Goumard M, Lenain JP, Leser E, Liu R, Lohse T, Lorentz M, Lypova I, Marandon V, Marcowith A, Mariaud C, Marx R, Maurin G, Maxted N, Mayer M, Meintjes PJ, Meyer M, Mitchell AM, Moderski R, Mohamed M, Morå K, Moulin E, Murach T, de Naurois M, Niederwanger F, Niemiec J, Oakes L, O'Brien P, Odaka H, Ohm S, Ostrowski M, Öttl S, Oya I, Padovani M, Panter M, Parsons RD, Paz Arribas M, Pekeur NW, Pelletier G, Perennes C, Petrucci PO, Peyaud B, Pita S, Poon H, Prokhorov D, Prokoph H, Pühlhofer G, Punch M, Quirrenbach A, Raab S, Reimer A, Reimer O, Renaud M, de Los Reyes R, Rieger F, Romoli C, Rosier-Lees S, Rowell G, Rudak B, Rulten CB, Sahakian V, Salek D, Sanchez DA, Santangelo A, Sasaki M, Schlickeiser R, Schüssler F, Schulz A, Schwanke U, Schwemmer S, Settimo M, Seyffert AS, Shafi N, Shilon I, Simoni R, Sol H, Spanier F, Spengler G, Spies F, Stawarz Ł, Steenkamp R, Stegmann C, Stinzing F, Stycz K, Sushch I, Tavernet JP, Tavernier T, Taylor AM, Terrier R, Tibaldo L, Tluczykont M, Trichard C, Tuffs R, van der Walt J, van Eldik C, van Soelen B, Vasileiadis G, Veh J, Venter C, Viana A, Vincent P, Vink J, Voisin F, Völk HJ, Vuillaume T, Wadiasingh Z, Wagner SJ, Wagner P, Wagner RM, White R, Wierzcholska A, Willmann P, Wörnlein A, Wouters D, Yang R, Zabalza V, Zaborov D, Zacharias M, Zdziarski AA, Zech A, Zefi F, Ziegler A, and Żywucka N

Abstract

A search for dark matter linelike signals iss performed in the vicinity of the Galactic Center by the H.E.S.S. experiment on observational data taken in 2014. An unbinned likelihood analysis iss developed to improve the sensitivity to linelike signals. The upgraded analysis along with newer data extend the energy coverage of the previous measurement down to 100 GeV. The 18 h of data collected with the H.E.S.S. array allow one to rule out at 95% C.L. the presence of a 130 GeV line (at l=-1.5°, b=0° and for a dark matter profile centered at this location) previously reported in Fermi-LAT data. This new analysis overlaps significantly in energy with previous Fermi-LAT and H.E.S.S., Results: No significant excess associated with dark matter annihilations was found in the energy range of 100 GeV to 2 TeV and upper limits on the gamma-ray flux and the velocity weighted annihilation cross section are derived adopting an Einasto dark matter halo profile. Expected limits for present and future large statistics H.E.S.S. observations are also given.

Published
2016
Full Text
View/download PDF

34. Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with H.E.S.S.

Author

Abdallah H, Abramowski A, Aharonian F, Ait Benkhali F, Akhperjanian AG, Angüner E, Arrieta M, Aubert P, Backes M, Balzer A, Barnard M, Becherini Y, Becker Tjus J, Berge D, Bernhard S, Bernlöhr K, Birsin E, Blackwell R, Böttcher M, Boisson C, Bolmont J, Bordas P, Bregeon J, Brun F, Brun P, Bryan M, Bulik T, Capasso M, Carr J, Casanova S, Chakraborty N, Chalme-Calvet R, Chaves RC, Chen A, Chevalier J, Chrétien M, Colafrancesco S, Cologna G, Condon B, Conrad J, Couturier C, Cui Y, Davids ID, Degrange B, Deil C, deWilt P, Djannati-Ataï A, Domainko W, Donath A, Drury LO, Dubus G, Dutson K, Dyks J, Dyrda M, Edwards T, Egberts K, Eger P, Ernenwein JP, Eschbach S, Farnier C, Fegan S, Fernandes MV, Fiasson A, Fontaine G, Förster A, Funk S, Füßling M, Gabici S, Gajdus M, Gallant YA, Garrigoux T, Giavitto G, Giebels B, Glicenstein JF, Gottschall D, Goyal A, Grondin MH, Grudzińska M, Hadasch D, Hahn J, Hawkes J, Heinzelmann G, Henri G, Hermann G, Hervet O, Hillert A, Hinton JA, Hofmann W, Hoischen C, Holler M, Horns D, Ivascenko A, Jacholkowska A, Jamrozy M, Janiak M, Jankowsky D, Jankowsky F, Jingo M, Jogler T, Jouvin L, Jung-Richardt I, Kastendieck MA, Katarzyński K, Katz U, Kerszberg D, Khélifi B, Kieffer M, King J, Klepser S, Klochkov D, Kluźniak W, Kolitzus D, Komin N, Kosack K, Krakau S, Kraus M, Krayzel F, Krüger PP, Laffon H, Lamanna G, Lau J, Lees JP, Lefaucheur J, Lefranc V, Lemière A, Lemoine-Goumard M, Lenain JP, Leser E, Lohse T, Lorentz M, Lui R, Lypova I, Marandon V, Marcowith A, Mariaud C, Marx R, Maurin G, Maxted N, Mayer M, Meintjes PJ, Menzler U, Meyer M, Mitchell AM, Moderski R, Mohamed M, Morå K, Moulin E, Murach T, de Naurois M, Niederwanger F, Niemiec J, Oakes L, Odaka H, Ohm S, Öttl S, Ostrowski M, Oya I, Padovani M, Panter M, Parsons RD, Paz Arribas M, Pekeur NW, Pelletier G, Petrucci PO, Peyaud B, Pita S, Poon H, Prokhorov D, Prokoph H, Pühlhofer G, Punch M, Quirrenbach A, Raab S, Reimer A, Reimer O, Renaud M, de Los Reyes R, Rieger F, Romoli C, Rosier-Lees S, Rowell G, Rudak B, Rulten CB, Sahakian V, Salek D, Sanchez DA, Santangelo A, Sasaki M, Schlickeiser R, Schüssler F, Schulz A, Schwanke U, Schwemmer S, Seyffert AS, Shafi N, Simoni R, Sol H, Spanier F, Spengler G, Spieß F, Stawarz L, Steenkamp R, Stegmann C, Stinzing F, Stycz K, Sushch I, Tavernet JP, Tavernier T, Taylor AM, Terrier R, Tluczykont M, Trichard C, Tuffs R, van der Walt J, van Eldik C, van Soelen B, Vasileiadis G, Veh J, Venter C, Viana A, Vincent P, Vink J, Voisin F, Völk HJ, Vuillaume T, Wadiasingh Z, Wagner SJ, Wagner P, Wagner RM, White R, Wierzcholska A, Willmann P, Wörnlein A, Wouters D, Yang R, Zabalza V, Zaborov D, Zacharias M, Zdziarski AA, Zech A, Zefi F, Ziegler A, and Żywucka N

Abstract

The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using γ-ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant γ-ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section ⟨σv⟩. These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach ⟨σv⟩ values of 6×10^{-26}  cm^{3} s^{-1} in the W^{+}W^{-} channel for a DM particle mass of 1.5 TeV, and 2×10^{-26}  cm^{3} s^{-1} in the τ^{+}τ^{-} channel for a 1 TeV mass. For the first time, ground-based γ-ray observations have reached sufficient sensitivity to probe ⟨σv⟩ values expected from the thermal relic density for TeV DM particles.

Published
2016
Full Text
View/download PDF

35. Characterization of SKAP/kinastrin isoforms: the N-terminus defines tissue specificity and Pontin binding.

Author

Cindric Vranesic A, Reiche J, Hoischen C, Wohlmann A, Bratsch J, Friedrich K, Günes B, Cappallo-Obermann H, Kirchhoff C, Diekmann S, Günes C, and Huber O

Subjects
Animals, Apoptosis, Humans, Male, Mice, Mitosis, Organ Specificity genetics, Protein Domains genetics, Protein Isoforms genetics, Protein Isoforms metabolism, Sperm Motility, Spermatogenesis, Spermatozoa metabolism, Testis metabolism, Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Microtubule-Associated Proteins genetics, Microtubule-Associated Proteins metabolism
Abstract

Small Kinetochore-Associated Protein (SKAP)/Kinastrin is a multifunctional protein with proposed roles in mitosis, apoptosis and cell migration. Exact mechanisms underlying its activities in these cellular processes are not completely understood. SKAP is predicted to have different isoforms, however, previous studies did not differentiate between them. Since distinct molecular architectures of protein isoforms often influence their localization and functions, this study aimed to examine the expression profile and functional differences between SKAP isoforms in human and mouse. Analyses of various human tissues and cells of different origin by RT-PCR, and by Western blotting and immunocytochemistry applying newly generated anti-SKAP monoclonal antibodies revealed that human SKAP exists in two protein isoforms: ubiquitously expressed SKAP16 and testis/sperm-specific SKAP1. In mouse, SKAP1 expression is detectable in testis at 4 weeks postnatally, when the first wave of spermatogenesis in mice is complete and the elongated spermatids are present in the testes. Furthermore, we identified Pontin as a new SKAP1 interaction partner. SKAP1 and Pontin co-localized in the flagellar region of human sperm suggesting a functional relevance for SKAP1-Pontin interaction in sperm motility. Since most previous studies on SKAP were performed with the testis-specific isoform SKAP1, our findings provide a new basis for future studies on the role of SKAP in both human somatic cells and male germ cells, including studies on male fertility., (© The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Published
2016
Full Text
View/download PDF

36. The CENP-T C-terminus is exclusively proximal to H3.1 and not to H3.2 or H3.3.

Author

Abendroth C, Hofmeister A, Hake SB, Kamweru PK, Miess E, Dornblut C, Küffner I, Deng W, Leonhardt H, Orthaus S, Hoischen C, and Diekmann S

Subjects
Amino Acid Sequence, Animals, Cell Line, Chromatin chemistry, Chromatin metabolism, Chromosomal Proteins, Non-Histone chemistry, Fluorescence Resonance Energy Transfer, HeLa Cells, Histones chemistry, Histones genetics, Humans, Kinetochores chemistry, Kinetochores metabolism, Luminescent Proteins chemistry, Luminescent Proteins genetics, Luminescent Proteins metabolism, Molecular Sequence Data, Protein Structure, Tertiary, Recombinant Fusion Proteins biosynthesis, Recombinant Fusion Proteins genetics, Sequence Alignment, Red Fluorescent Protein, Chromosomal Proteins, Non-Histone metabolism, Histones metabolism
Abstract

The kinetochore proteins assemble onto centromeric chromatin and regulate DNA segregation during cell division. The inner kinetochore proteins bind centromeres while most outer kinetochore proteins assemble at centromeres during mitosis, connecting the complex to microtubules. The centromere-kinetochore complex contains specific nucleosomes and nucleosomal particles. CENP-A replaces canonical H3 in centromeric nucleosomes, defining centromeric chromatin. Next to CENP-A, the CCAN multi-protein complex settles which contains CENP-T/W/S/X. These four proteins are described to form a nucleosomal particle at centromeres. We had found the CENP-T C-terminus and the CENP-S termini next to histone H3.1 but not to CENP-A, suggesting that the Constitutive Centromere-Associated Network (CCAN) bridges a CENP-A- and a H3-containing nucleosome. Here, we show by in vivo FRET that this proximity between CENP-T and H3 is specific for H3.1 but neither for the H3.1 mutants H3.1(C96A) and H3.1(C110A) nor for H3.2 or H3.3. We also found CENP-M next to H3.1 but not to these H3.1 mutants. Consistently, we detected CENP-M next to CENP-S. These data elucidate the local molecular neighborhood of CCAN proteins next to a H3.1-containing centromeric nucleosome. They also indicate an exclusive position of H3.1 clearly distinct from H3.2, thus documenting a local, and potentially also functional, difference between H3.1 and H3.2.

Published
2015
Full Text
View/download PDF

37. Biomolecular dynamics and binding studies in the living cell.

Author

Diekmann S and Hoischen C

Subjects
Animals, Cell Survival, Humans, Luminescent Proteins metabolism, Nanotechnology, Protein Binding, Biophysics methods, Proteins metabolism
Abstract

Isolation and preparation of proteins of higher organisms often is a tedious task. In the case of success, the properties of these proteins and their interactions with other proteins can be studied in vitro. If however, these proteins are modified in the cell in order to gain or change function, this is non-trivial to correctly realise in vitro. When, furthermore, the cellular function requires the interplay of more than one or two proteins, in vitro experiments for the analysis of this situation soon become complex. Instead, we thus try to obtain information on the molecular properties of proteins in the living cell. Then, the cell takes care of correct protein folding and modification. A series of molecular techniques are, and new ones become, available which allow for measuring molecular protein properties in the living cell, offering information on concentration (FCS), dynamics (FCS, RICS, FRAP), location (PALM, STED), interactions (F3H, FCCS) and protein proximities (FRET, BRET, FLIM, BiFC). Here, these techniques are presented with their advantages and drawbacks, with examples from our current kinetochore research. The review is supposed to give orientation to researchers planning to enter the field, and inform which techniques help us to gain molecular information on a multi-protein complex. We show that the field of cellular imaging is in a phase of transition: in the future, an increasing amount of physico-chemical data can be determined in the living cell., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Published
2014
Full Text
View/download PDF

38. A CENP-S/X complex assembles at the centromere in S and G2 phases of the human cell cycle.

Author

Dornblut C, Quinn N, Monajambashi S, Prendergast L, van Vuuren C, Münch S, Deng W, Leonhardt H, Cardoso MC, Hoischen C, Diekmann S, and Sullivan KF

Subjects
Apoptosis Regulatory Proteins genetics, Binding Sites, Cell Line, Tumor, Chromosomal Proteins, Non-Histone genetics, Chromosomal Proteins, Non-Histone metabolism, DNA metabolism, DNA Damage, DNA-Binding Proteins genetics, Fluorescence Resonance Energy Transfer, G2 Phase, HeLa Cells, Histones genetics, Histones metabolism, Humans, Models, Molecular, Nuclear Proteins genetics, S Phase, Tumor Suppressor Proteins genetics, Apoptosis Regulatory Proteins metabolism, Centromere metabolism, DNA-Binding Proteins metabolism, Nuclear Proteins metabolism, Tumor Suppressor Proteins metabolism
Abstract

The functional identity of centromeres arises from a set of specific nucleoprotein particle subunits of the centromeric chromatin fibre. These include CENP-A and histone H3 nucleosomes and a novel nucleosome-like complex of CENPs -T, -W, -S and -X. Fluorescence cross-correlation spectroscopy and Förster resonance energy transfer (FRET) revealed that human CENP-S and -X exist principally in complex in soluble form and retain proximity when assembled at centromeres. Conditional labelling experiments show that they both assemble de novo during S phase and G2, increasing approximately three- to fourfold in abundance at centromeres. Fluorescence recovery after photobleaching (FRAP) measurements documented steady-state exchange between soluble and assembled pools, with CENP-X exchanging approximately 10 times faster than CENP-S (t1/2 ∼ 10 min versus 120 min). CENP-S binding to sites of DNA damage was quite distinct, with a FRAP half-time of approximately 160 s. Fluorescent two-hybrid analysis identified CENP-T as a uniquely strong CENP-S binding protein and this association was confirmed by FRET, revealing a centromere-bound complex containing CENP-S, CENP-X and CENP-T in proximity to histone H3 but not CENP-A. We propose that deposition of the CENP-T/W/S/X particle reveals a kinetochore-specific chromatin assembly pathway that functions to switch centromeric chromatin to a mitosis-competent state after DNA replication. Centromeres shuttle between CENP-A-rich, replication-competent and H3-CENP-T/W/S/X-rich mitosis-competent compositions in the cell cycle.

Published
2014
Full Text
View/download PDF

39. Rule-based modeling and simulations of the inner kinetochore structure.

Author

Tschernyschkow S, Herda S, Gruenert G, Döring V, Görlich D, Hofmeister A, Hoischen C, Dittrich P, Diekmann S, and Ibrahim B

Subjects
Binding Sites, Computer Simulation, Protein Binding, Protein Conformation, Algorithms, Kinetochores chemistry, Kinetochores ultrastructure, Models, Biological, Models, Chemical, Models, Molecular
Abstract

Background: Combinatorial complexity is a central problem when modeling biochemical reaction networks, since the association of a few components can give rise to a large variation of protein complexes. Available classical modeling approaches are often insufficient for the analysis of very large and complex networks in detail. Recently, we developed a new rule-based modeling approach that facilitates the analysis of spatial and combinatorially complex problems. Here, we explore for the first time how this approach can be applied to a specific biological system, the human kinetochore, which is a multi-protein complex involving over 100 proteins., Results: Applying our freely available SRSim software to a large data set on kinetochore proteins in human cells, we construct a spatial rule-based simulation model of the human inner kinetochore. The model generates an estimation of the probability distribution of the inner kinetochore 3D architecture and we show how to analyze this distribution using information theory. In our model, the formation of a bridge between CenpA and an H3 containing nucleosome only occurs efficiently for higher protein concentration realized during S-phase but may be not in G1. Above a certain nucleosome distance the protein bridge barely formed pointing towards the importance of chromatin structure for kinetochore complex formation. We define a metric for the distance between structures that allow us to identify structural clusters. Using this modeling technique, we explore different hypothetical chromatin layouts., Conclusions: Applying a rule-based network analysis to the spatial kinetochore complex geometry allowed us to integrate experimental data on kinetochore proteins, suggesting a 3D model of the human inner kinetochore architecture that is governed by a combinatorial algebraic reaction network. This reaction network can serve as bridge between multiple scales of modeling. Our approach can be applied to other systems beyond kinetochores., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Published
2013
Full Text
View/download PDF

40. Cell-cycle-dependent structural transitions in the human CENP-A nucleosome in vivo.

Author

Bui M, Dimitriadis EK, Hoischen C, An E, Quénet D, Giebe S, Nita-Lazar A, Diekmann S, and Dalal Y

Subjects
Autoantigens chemistry, Cell Cycle, Centromere metabolism, Centromere Protein A, Chromosomal Proteins, Non-Histone chemistry, DNA Replication, DNA-Binding Proteins metabolism, HEK293 Cells, HeLa Cells, Histones chemistry, Histones metabolism, Humans, Models, Molecular, Protein Structure, Tertiary, Autoantigens metabolism, Chromosomal Proteins, Non-Histone metabolism, Nucleosomes metabolism
Abstract

In eukaryotes, DNA is packaged into chromatin by canonical histone proteins. The specialized histone H3 variant CENP-A provides an epigenetic and structural basis for chromosome segregation by replacing H3 at centromeres. Unlike exclusively octameric canonical H3 nucleosomes, CENP-A nucleosomes have been shown to exist as octamers, hexamers, and tetramers. An intriguing possibility reconciling these observations is that CENP-A nucleosomes cycle between octamers and tetramers in vivo. We tested this hypothesis by tracking CENP-A nucleosomal components, structure, chromatin folding, and covalent modifications across the human cell cycle. We report that CENP-A nucleosomes alter from tetramers to octamers before replication and revert to tetramers after replication. These structural transitions are accompanied by reversible chaperone binding, chromatin fiber folding changes, and previously undescribed modifications within the histone fold domains of CENP-A and H4. Our results reveal a cyclical nature to CENP-A nucleosome structure and have implications for the maintenance of epigenetic memory after centromere replication., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Published
2012
Full Text
View/download PDF

41. CENP-C facilitates the recruitment of M18BP1 to centromeric chromatin.

Author

Dambacher S, Deng W, Hahn M, Sadic D, Fröhlich J, Nuber A, Hoischen C, Diekmann S, Leonhardt H, and Schotta G

Subjects
Amino Acid Sequence, Animals, Cell Cycle, Cell Line, Chromosomal Proteins, Non-Histone chemistry, Chromosomal Proteins, Non-Histone deficiency, Chromosomal Proteins, Non-Histone genetics, Humans, Mice, Molecular Sequence Data, Protein Binding, Protein Structure, Tertiary, Protein Transport, RNA Interference, Centromere metabolism, Chromatin metabolism, Chromosomal Proteins, Non-Histone metabolism
Abstract

Centromeres are important structural constituents of chromosomes that ensure proper chromosome segregation during mitosis by providing defined sites for kinetochore attachment. In higher eukaryotes, centromeres have no specific DNA sequence and thus, they are rather determined through epigenetic mechanisms. A fundamental process in centromere establishment is the incorporation of the histone variant CENP-A into centromeric chromatin, which provides a binding platform for the other centromeric proteins. The Mis18 complex, and, in particular, its member M18BP1 was shown to be essential for both incorporation and maintenance of CENP-A. Here we show that M18BP1 displays a cell cycle-regulated association with centromeric chromatin in mouse embryonic stem cells. M18BP1 is highly enriched at centromeric regions from late anaphase through to G1 phase. An interaction screen against 16 core centromeric proteins revealed a novel interaction of M18BP1 with CENP-C. We mapped the interaction domain in M18BP1 to a central region containing a conserved SANT domain and in CENP-C to the C-terminus. Knock-down of CENP-C leads to reduced M18BP1 association and lower CENP-A levels at centromeres, suggesting that CENP-C works as an important factor for centromeric M18BP1 recruitment and thus for maintaining centromeric CENP-A.

Published
2012
Full Text
View/download PDF

42. Step-wise assembly, maturation and dynamic behavior of the human CENP-P/O/R/Q/U kinetochore sub-complex.

Author

Eskat A, Deng W, Hofmeister A, Rudolphi S, Emmerth S, Hellwig D, Ulbricht T, Döring V, Bancroft JM, McAinsh AD, Cardoso MC, Meraldi P, Hoischen C, Leonhardt H, and Diekmann S

Subjects
Blotting, Western, Cell Cycle Proteins, Cell Line, Tumor, Chromosomal Proteins, Non-Histone genetics, Fluorescence Resonance Energy Transfer, HeLa Cells, Histones, Humans, Nuclear Proteins genetics, Chromosomal Proteins, Non-Histone metabolism, Kinetochores metabolism, Nuclear Proteins metabolism
Abstract

Kinetochores are multi-protein megadalton assemblies that are required for attachment of microtubules to centromeres and, in turn, the segregation of chromosomes in mitosis. Kinetochore assembly is a cell cycle regulated multi-step process. The initial step occurs during interphase and involves loading of the 15-subunit constitutive centromere associated complex (CCAN), which contains a 5-subunit (CENP-P/O/R/Q/U) sub-complex. Here we show using a fluorescent three-hybrid (F3H) assay and fluorescence resonance energy transfer (FRET) in living mammalian cells that CENP-P/O/R/Q/U subunits exist in a tightly packed arrangement that involves multifold protein-protein interactions. This sub-complex is, however, not pre-assembled in the cytoplasm, but rather assembled on kinetochores through the step-wise recruitment of CENP-O/P heterodimers and the CENP-P, -O, -R, -Q and -U single protein units. SNAP-tag experiments and immuno-staining indicate that these loading events occur during S-phase in a manner similar to the nucleosome binding components of the CCAN, CENP-T/W/N. Furthermore, CENP-P/O/R/Q/U binding to the CCAN is largely mediated through interactions with the CENP-N binding protein CENP-L as well as CENP-K. Once assembled, CENP-P/O/R/Q/U exchanges slowly with the free nucleoplasmic pool indicating a low off-rate for individual CENP-P/O/R/Q/U subunits. Surprisingly, we then find that during late S-phase, following the kinetochore-binding step, both CENP-Q and -U but not -R undergo oligomerization. We propose that CENP-P/O/R/Q/U self-assembles on kinetochores with varying stoichiometry and undergoes a pre-mitotic maturation step that could be important for kinetochores switching into the correct conformation necessary for microtubule-attachment.

Published
2012
Full Text
View/download PDF

43. Dynamics of CENP-N kinetochore binding during the cell cycle.

Author

Hellwig D, Emmerth S, Ulbricht T, Döring V, Hoischen C, Martin R, Samora CP, McAinsh AD, Carroll CW, Straight AF, Meraldi P, and Diekmann S

Subjects
Autoantigens genetics, Autoantigens metabolism, Cell Line, Centromere genetics, Centromere Protein A, Chromosomal Proteins, Non-Histone genetics, DNA Replication, Humans, Protein Binding, Cell Cycle, Centromere metabolism, Chromosomal Proteins, Non-Histone metabolism, Kinetochores metabolism
Abstract

Accurate chromosome segregation requires the assembly of kinetochores, multiprotein complexes that assemble on the centromere of each sister chromatid. A key step in this process involves binding of the constitutive centromere-associated network (CCAN) to CENP-A, the histone H3 variant that constitutes centromeric nucleosomes. This network is proposed to operate as a persistent structural scaffold for assembly of the outer kinetochore during mitosis. Here, we show by fluorescence resonance energy transfer (FRET) that the N-terminus of CENP-N lies in close proximity to the N-terminus of CENP-A in vivo, consistent with in vitro data showing direct binding of CENP-N to CENP-A. Furthermore, we demonstrate in living cells that CENP-N is bound to kinetochores during S phase and G2, but is largely absent from kinetochores during mitosis and G1. By measuring the dynamics of kinetochore binding, we reveal that CENP-N undergoes rapid exchange in G1 until the middle of S phase when it becomes stably associated with kinetochores. The majority of CENP-N is loaded during S phase and dissociates again during G2. We propose a model in which CENP-N functions as a fidelity factor during centromeric replication and reveal that the CCAN network is considerably more dynamic than previously appreciated.

Published
2011
Full Text
View/download PDF

44. Segrosome assembly at the pliable parH centromere.

Author

Wu M, Zampini M, Bussiek M, Hoischen C, Diekmann S, and Hayes F

Subjects
Bacterial Proteins chemistry, Binding Sites, Centromere chemistry, DNA, Bacterial chemistry, DNA, Bacterial metabolism, DNA, Bacterial ultrastructure, DNA-Binding Proteins chemistry, Operator Regions, Genetic, Plasmids metabolism, Bacterial Proteins metabolism, Centromere metabolism, DNA-Binding Proteins metabolism, Plasmids genetics
Abstract

The segrosome of multiresistance plasmid TP228 comprises ParF, which is a member of the ParA ATPase superfamily, and the ParG ribbon-helix-helix factor that assemble jointly on the parH centromere. Here we demonstrate that the distinctive parH site (∼100-bp) consists of an array of degenerate tetramer boxes interspersed by AT-rich spacers. Although numerous consecutive AT-steps are suggestive of inherent curvature, parH lacks an intrinsic bend. Sequential deletion of parH tetramers progressively reduced centromere function. Nevertheless, the variant subsites could be rearranged in different geometries that accommodated centromere activity effectively revealing that the site is highly elastic in vivo. ParG cooperatively coated parH: proper centromere binding necessitated the protein's N-terminal flexible tails which modulate the centromere binding affinity of ParG. Interaction of the ParG ribbon-helix-helix domain with major groove bases in the tetramer boxes likely provides direct readout of the centromere. In contrast, the AT-rich spacers may be implicated in indirect readout that mediates cooperativity between ParG dimers assembled on adjacent boxes. ParF alone does not bind parH but instead loads into the segrosome interactively with ParG, thereby subtly altering centromere conformation. Assembly of ParF into the complex requires the N-terminal flexible tails in ParG that are contacted by ParF.

Published
2011
Full Text
View/download PDF

45. Premitotic assembly of human CENPs -T and -W switches centromeric chromatin to a mitotic state.

Author

Prendergast L, van Vuuren C, Kaczmarczyk A, Doering V, Hellwig D, Quinn N, Hoischen C, Diekmann S, and Sullivan KF

Subjects
Cell Cycle, G1 Phase, HeLa Cells, Humans, S Phase, Spindle Apparatus, Centromere metabolism, Chromatin metabolism, Chromosomal Proteins, Non-Histone metabolism, Mitosis
Abstract

Centromeres are differentiated chromatin domains, present once per chromosome, that direct segregation of the genome in mitosis and meiosis by specifying assembly of the kinetochore. They are distinct genetic loci in that their identity in most organisms is determined not by the DNA sequences they are associated with, but through specific chromatin composition and context. The core nucleosomal protein CENP-A/cenH3 plays a primary role in centromere determination in all species and directs assembly of a large complex of associated proteins in vertebrates. While CENP-A itself is stably transmitted from one generation to the next, the nature of the template for centromere replication and its relationship to kinetochore function are as yet poorly understood. Here, we investigate the assembly and inheritance of a histone fold complex of the centromere, the CENP-T/W complex, which is integrated with centromeric chromatin in association with canonical histone H3 nucleosomes. We have investigated the cell cycle regulation, timing of assembly, generational persistence, and requirement for function of CENPs -T and -W in the cell cycle in human cells. The CENP-T/W complex assembles through a dynamic exchange mechanism in late S-phase and G2, is required for mitosis in each cell cycle and does not persist across cell generations, properties reciprocal to those measured for CENP-A. We propose that the CENP-A and H3-CENP-T/W nucleosome components of the centromere are specialized for centromeric and kinetochore activities, respectively. Segregation of the assembly mechanisms for the two allows the cell to switch between chromatin configurations that reciprocally support the replication of the centromere and its conversion to a mitotic state on postreplicative chromatin., Competing Interests: The authors have declared that no competing interests exist.

Published
2011
Full Text
View/download PDF

46. Theoretical study of lipid biosynthesis in wild-type Escherichia coli and in a protoplast-type L-form using elementary flux mode analysis.

Author

Kenanov D, Kaleta C, Petzold A, Hoischen C, Diekmann S, Siddiqui RA, and Schuster S

Subjects
Acyltransferases deficiency, Acyltransferases genetics, Acyltransferases metabolism, Escherichia coli enzymology, Escherichia coli genetics, Escherichia coli Proteins genetics, Gene Knockout Techniques, Mutation genetics, Escherichia coli metabolism, Escherichia coli Proteins metabolism, Lipids biosynthesis, Models, Theoretical
Abstract

In the present study, we investigated lipid biosynthesis in the bacterium Escherichia coli by mathematical modeling. In particular, we studied the interaction between the subsystems producing unsaturated and saturated fatty acids, phospholipids, lipid A, and cardiolipin. The present analysis was carried out both for the wild-type and for several in silico knockout mutants, using the concept of elementary flux modes. Our results confirm that, in the wild type, there are four main products: L1-phosphatidylethanolamine, lipid A, lipid A (cold-adapted), and cardiolipin. We found that each of these compounds is produced on several different routes, indicating a high redundancy of the system under study. By analysis of the elementary flux modes remaining after the knockout of genes of lipid biosynthesis, and comparison with publicly available data on single-gene knockouts in vivo, we were able to determine the metabolites essential for the survival of the cell. Furthermore, we analyzed a set of mutations that occur in a cell wall-free mutant of Escherichia coli W1655F+. We postulate that the mutant is not capable of producing both forms of lipid A, when the combination of mutations is considered to make a nonfunctional pathway. This is in contrast to gene essentiality data showing that lipid A synthesis is indispensable for the survival of the cell. The loss of the outer membrane in the cell wall-free mutant, however, shows that lipid A is dispensable as the main component of the outer surface structure in this particular E. coli strain.

Published
2010
Full Text
View/download PDF

47. Sequence-specific physical properties of African green monkey alpha-satellite DNA contribute to centromeric heterochromatin formation.

Author

Bussiek M, Hoischen C, Diekmann S, and Bennink ML

Subjects
Animals, Base Sequence, Chlorocebus aethiops, Microscopy, Atomic Force, Molecular Sequence Data, Centromere genetics, DNA, Satellite genetics, Heterochromatin genetics
Abstract

Satellite DNA, a major component of eukaryotic centromeric heterochromatin, is potentially associated with the processes ensuring the faithful segregation of the genetic material during cell division. Structural properties of alpha-satellite DNA (AS) from African green monkey (AGM) were studied. Atomic force microscopy imaging showed smaller end-to-end distances of AS fragments than would be expected for the persistence length of random sequence DNA. The apparent persistence length of the AS was determined as 35nm. Gel-electrophoresis indicated only a weak contribution of intrinsic curvature to the DNA conformations suggesting an additional contribution of an elevated bending flexibility to the reduced end-to-end distances. Next, the force-extension behavior of the naked AS and in complex with nucleosomes was studied using optical tweezers. The naked AS showed a reduced overstretching transition force (-18% the value determined for random DNA) and higher forces required to straighten the DNA. Finally, reconstituted AS nucleosomes disrupted at significantly higher forces as compared with random DNA nucleosomes which is probably due to structural properties of the AS which stabilize the nucleosomes. The data support that the AS plays a role in the formation of centromeric heterochromatin due to specific structural properties and suggest that a relatively higher mechanical stability of nucleosomes is important in AGM-AS chromatin.

Published
2009
Full Text
View/download PDF

48. Acceptor-photobleaching FRET analysis of core kinetochore and NAC proteins in living human cells.

Author

Hellwig D, Hoischen C, Ulbricht T, and Diekmann S

Subjects
Bacterial Proteins genetics, Blotting, Western, Cell Line, Tumor, Centromere Protein B chemistry, Centromere Protein B metabolism, Chromosomal Proteins, Non-Histone chemistry, Chromosomal Proteins, Non-Histone metabolism, Fluorescence Resonance Energy Transfer methods, Green Fluorescent Proteins genetics, Humans, Interphase physiology, Kinetochores metabolism, Luminescent Proteins genetics, Nuclear Proteins metabolism, Photobleaching, Transfection, Kinetochores chemistry, Nuclear Proteins chemistry
Abstract

Faithful chromatin segregation is mediated and controlled by the kinetochore protein network which assembles at centromeres. In this study, the neighbourhood relations of inner kinetochore and nucleosome-associated complex (NAC) proteins were analysed in living human interphase cells by acceptor photobleaching FRET. The data indicate that CENP-U is in close vicinity to CENP-I as well as to CENP-B and that CENP-M is close to CENP-T.

Published
2009
Full Text
View/download PDF

49. Linker histone H1 is present in centromeric chromatin of living human cells next to inner kinetochore proteins.

Author

Orthaus S, Klement K, Happel N, Hoischen C, and Diekmann S

Subjects
Centromere chemistry, Centromere Protein A, Centromere Protein B antagonists & inhibitors, Centromere Protein B genetics, Chromatin chemistry, Fluorescence Resonance Energy Transfer, HeLa Cells, Histones analysis, Humans, Kinetochores metabolism, Microscopy, Fluorescence, RNA Interference, Autoantigens metabolism, Centromere metabolism, Centromere Protein B metabolism, Chromosomal Proteins, Non-Histone metabolism, Histones metabolism
Abstract

The vertebrate kinetochore complex assembles at the centromere on alpha-satellite DNA. In humans, alpha-satellite DNA has a repeat length of 171 bp slightly longer than the DNA in the chromatosome containing the linker histone H1. The centromere-binding protein CENP-B binds specifically to alpha-satellite DNA with properties of a centromeric-linker histone. Here, we analysed if linker histone H1 is present at or excluded from centromeric chromatin by CENP-B. By immunostaining we detected the presence, but no enrichment or depletion of five different H1 subtypes at centromeric chromatin. The binding dynamics of H1 at centromeric sites were similar to that at other locations in the genome. These dynamics did not change in CENP-B depleted cells, suggesting that CENP-B and H1 co-exist in centromeric chromatin with no or little functional overlap. By bimolecular fluorescence complementation (BiFC) and Förster resonance energy transfer (FRET), we revealed that the linker histone H1 subtypes H1 degrees and H1.2 bind to centromeric chromatin in interphase nuclei in direct neighbourhood to inner kinetochore proteins.

Published
2009
Full Text
View/download PDF

50. Bacterial L-forms.

Author

Allan EJ, Hoischen C, and Gumpert J

Subjects
Animals, Bacterial Infections physiopathology, Humans, Protoplasts cytology, Bacteria cytology, Bacteria growth & development, Bacteria pathogenicity, Bacteria ultrastructure, L Forms cytology, L Forms growth & development, L Forms pathogenicity, L Forms ultrastructure
Abstract

L-forms are "cell wall-deficient" bacteria which are able to grow as spheroplasts or protoplasts. They can be differentiated into four types depending on their ability to revert to the parental, cell-walled form and to the extent of their cell-wall modification. L-forms are significant in modern science because of their contributions to an improved understanding of principal questions and their interactions with eukaryotes. This review particularly focuses on research using stable protoplast-type L-forms which have contributed to a better understanding of the structural and functional organisation of the cytoplasmic membrane and of cell division. These L-forms, which have only a single surrounding bilayer membrane, also represent a unique expression system for production of recombinant proteins. A large proportion of L-form publications concern their putative role in human disease and its therapy, a topic which is discussed briefly. L-forms have also been used to form intracellular associations with plant cells and have been shown to elicit induced disease resistance offering a novel method for plant protection. The recent decline in active research on L-forms is a concern as knowledge and experience, as well as unique L-form strains which have been maintained for decades, are being lost.

Published
2009
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results