Search

Your search keyword '"Gibrat, Rémy"' showing total 68 results
Start Over Author "Gibrat, Rémy"
68 results on '"Gibrat, Rémy"'

13. Characterization of the grapevine Shaker K+ channel VvK3.1 supports its function in massive potassium fluxes necessary for berry potassium loading and pulvinus-actuated leaf movements

Author

Agence Nationale de la Recherche (France), European Commission, Commission Nationale des Bourses Extérieures (Madagascar), Nieves-Cordones, Manuel [0000-0002-4015-0981], Nieves-Cordones, Manuel, Andrianteranagna, Mamy, Cuéllar, Teresa, Chérel, Isabelle, Gibrat, Rémy, Boeglin, Martin, Moreau, Bertrand, Paris, Nadine, Verdeil, Jean-Luc, Zimmermann, Sabine Dagmar, Gaillard, Isabelle, Agence Nationale de la Recherche (France), European Commission, Commission Nationale des Bourses Extérieures (Madagascar), Nieves-Cordones, Manuel [0000-0002-4015-0981], Nieves-Cordones, Manuel, Andrianteranagna, Mamy, Cuéllar, Teresa, Chérel, Isabelle, Gibrat, Rémy, Boeglin, Martin, Moreau, Bertrand, Paris, Nadine, Verdeil, Jean-Luc, Zimmermann, Sabine Dagmar, and Gaillard, Isabelle

Abstract

In grapevine, climate changes lead to increased berry potassium (K+) contents that result in must with low acidity. Consequently, wines are becoming ‘flat’ to the taste, with poor organoleptic properties and low potential aging, resulting in significant economic loss. Precise investigation into the molecular determinants controlling berry K+ accumulation during its development are only now emerging. Here, we report functional characterization by electrophysiology of a new grapevine Shaker-type K+ channel, VvK3.1. The analysis of VvK3.1 expression patterns was performed by qPCR and in situ hybridization. We found that VvK3.1 belongs to the AKT2 channel phylogenetic branch and is a weakly rectifying channel, mediating both inward and outward K+ currents. We showed that VvK3.1 is highly expressed in the phloem and in a unique structure located at the two ends of the petiole, identified as a pulvinus. From the onset of fruit ripening, all data support the role of the VvK3.1 channel in the massive K+ fluxes from the phloem cell cytosol to the berry apoplast during berry K+ loading. Moreover, the high amount of VvK3.1 transcripts detected in the pulvinus strongly suggests a role for this Shaker in the swelling and shrinking of motor cells involved in paraheliotropic leaf movements

Published
2019

15. Non invasive imaging use to shed light on pH at both sides of the plasma membrane interface in living root

Author

Paris, Nadine, Martiniere, Alexandre, Gibrat, Rémy, Sentenac, Herve, Dumont, Xavier, Gaillard, Isabelle, Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
racine, arabidopsis, apoplaste, gradient de protons, barrière apoplastique, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, apoplast, root, absorption du calcium
Abstract

The proton gradient across a biological membrane is a matter of great importance for plant development and nutrition. To gain a better understanding of proton distribution in the plant root apoplast as well as across the plasma membrane, we generated Arabidopsis plants expressing stable membrane‐anchored ratiometric fluorescent sensors based on pHluorin. These sensors enabled non‐invasive and specific pH measurements in mature root cells from the medium‐epidermis interface up to the inner cell layers that lie beyond the Casparian strip. We found that the membrane‐associated apoplastic pH was much more alkaline than in the overall apoplastic space. In apparent contradiction with the direct connection between root intercellular space and the external medium, proton concentration associated with the plasma membrane was very stable, even when the growth medium pH was altered. The plasma membrane‐associated pH in the stele was the most preserved, and displayed the lowest apoplastic pH (6.0 to 6.1) and the highest transmembrane delta pH (1.5 to 2.2). Both pH values also correlated well with optimal activities of channels and transporters involved in ion uptake and redistribution from the root to the aerial part. In growth medium where ionic content is minimized, the root plasma membrane‐associated pH was more affected by environmental proton changes, especially for the most external cell layers. Calcium concentration appears to play a major role in apoplastic pH under these restrictive conditions, supporting a role for the cell wall in pH homeostasis of the unstirred surface layer of plasma membrane in mature roots. Alexandre Martinière, Rémy Gibrat, Hervé Sentenac, Xavier Dumont, Isabelle Gaillard and Nadine Paris. Shedding light on pH at both sides of the root plasma membrane interface using non‐invasive imaging. PNAS, in press under embargo.

Published
2018

17. Characterization of the grapevine Shaker K+ channel VvK3.1 supports its function in massive potassium fluxes necessary for berry potassium loading and pulvinus‐actuated leaf movements.

Author

Nieves‐Cordones, Manuel, Andrianteranagna, Mamy, Cuéllar, Teresa, Chérel, Isabelle, Gibrat, Rémy, Boeglin, Martin, Moreau, Bertrand, Paris, Nadine, Verdeil, Jean‐Luc, Zimmermann, SabineDagmar, and Gaillard, Isabelle

Subjects
GRAPES, PHLOEM, PLANT cells & tissues, CLIMATE change, IN situ hybridization
Abstract

Summary: In grapevine, climate changes lead to increased berry potassium (K+) contents that result in must with low acidity. Consequently, wines are becoming 'flat' to the taste, with poor organoleptic properties and low potential aging, resulting in significant economic loss. Precise investigation into the molecular determinants controlling berry K+ accumulation during its development are only now emerging.Here, we report functional characterization by electrophysiology of a new grapevine Shaker‐type K+ channel, VvK3.1. The analysis of VvK3.1 expression patterns was performed by qPCR and in situ hybridization.We found that VvK3.1 belongs to the AKT2 channel phylogenetic branch and is a weakly rectifying channel, mediating both inward and outward K+ currents. We showed that VvK3.1 is highly expressed in the phloem and in a unique structure located at the two ends of the petiole, identified as a pulvinus.From the onset of fruit ripening, all data support the role of the VvK3.1 channel in the massive K+ fluxes from the phloem cell cytosol to the berry apoplast during berry K+ loading. Moreover, the high amount of VvK3.1 transcripts detected in the pulvinus strongly suggests a role for this Shaker in the swelling and shrinking of motor cells involved in paraheliotropic leaf movements. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

18. The Arabidopsis NO3- efflux transporter NAXT2 is involved in root-to-shoot NO3- translocation and contributes to plant tolerance to salt stress

Author

Taochy, Christelle, Ipotesi, Émilie, Gaillard, Isabelle, Conejero, Geneviève, Tillard, Pascal, Sentenac, Herve, Simonneau, Thierry, Gibrat, Rémy, Boyer, Jean-Christophe, Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Écophysiologie des Plantes sous Stress environnementaux (LEPSE), Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Gordon Research Conferences (GRC). USA.

Subjects
inorganic chemicals, transporteur NAXT2, arabidopsis, [SDV.OT]Life Sciences [q-bio]/Other [q-bio.OT], organic chemicals, fungi, stress salin, food and beverages, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, absorption du nitrate
Abstract

The Arabidopsis NO3- efflux transporter NAXT2 is involved in root-to-shoot NO3- translocation and contributes to plant tolerance to salt stress. Salt & Water Stress in Plants

Published
2012

20. Passive Nitrate Transport by Root Plasma Membrane Vesicles Exhibits an Acidic Optimal pH Like the H+-ATPase1

Author

Pouliquin, Pierre, Boyer, Jean-Christophe, Grouzis, Jean-Pierre, and Gibrat, Rémy

Subjects
Nitrates, Cell Membrane, Coated Vesicles, Biological Transport, Hydrogen-Ion Concentration, Plant Roots, Zea mays, Research Article
Abstract

The net initial passive flux (J(Ni)) in reconstituted plasma membrane (PM) vesicles from maize (Zea mays) root cells was measured as recently described (P. Pouliquin, J.-P. Grouzis, R. Gibrat ¿1999 Biophys J 76: 360-373). J(Ni) in control liposomes responded to membrane potential or to NO(3)(-) as expected from the Goldman-Hodgkin-Katz diffusion theory. J(Ni) in reconstituted PM vesicles exhibited an additional component (J(Nif)), which was saturable (K(m) for NO(3)(-) approximately 3 mM, with J(Nifmax) corresponding to 60 x 10(-9) mol m(-2) s(-1) at the native PM level) and selective (NO(3)(-) = ClO(3)(-)Br(-)Cl(-) = NO(2)(-); relative fluxes at 5 mM: 1:0.34:0.19). J(Nif) was totally inhibited by La(3+) and the arginine reagent phenylglyoxal. J(Nif) was voltage dependent, with an optimum voltage at 105 mV at pH 6.5. The activation energy of J(Nif) was high (129 kJ mol(-1)), close to that of the H(+)-ATPase (155 kJ mol(-1)), and J(Nif) displayed the same acidic optimal pH (pH 6.5) as that of the H(+) pump. This is the first example, to our knowledge, of a secondary transport at the plant PM with such a feature. Several properties of the NO(3)(-) uniport seem poorly compatible with that reported for plant anion channels and to be attributable instead to a classical carrier. The physiological relevance of these findings is suggested.

Published
2000

21. Mg2+/H+ antiport activity in solubilized and reconstituted protein fractions from Hevea brasiliensis lutoid vacuole membrane

Author

Amalou, Z., Enjuto, M., Grouzis, J.P., Prevot, J.C., Jacob, J.L., Grignon, C., Gibrat, Rémy, ProdInra, Migration, Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
Membrane cellulaire, Échange d'ion, Protéine, F60 - Physiologie et biochimie végétales, Hevea brasiliensis, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, Vacuole, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, ComputingMilieux_MISCELLANEOUS
Abstract

Les protéines des vésicules lutoïdiques d'H. brasiliensis ont été solubilisées par l'octylglucoside et soumises à une filtration sur gel et une chromatographie d'échange d'ion puis reconstituées. Après les 2 étapes de chromatographie, l'activité d'échange spécifique Mg2+/H+ est 10 fois plus importante que chez les protéines initiales solubilisées, sans perte significative d'activité totale. 2 fractions actives clairement séparées sont éluées à 300 et 600 mM KCl. Elles montrent des activités spécifiques de transport Mg2+/H+ comparables. Des anticorps polyclonaux (PAB) sont dirigés contre chaque fraction. Les 2 PAB inhibent spécifiquement la reconstitution de l'activité de l'antiport après incubation avec un détergent et des lipides de soja. De plus, les effets inhibiteurs des 2 PAB sont cumulatifs, et une inhibition totale est observée lorsqu'ils sont utilisés ensemble. Ces résultats confirment l'hypothèse de l'existence de 2 systèmes de transport Mg2+/H+ distincts et non homologues dans la membrane tonoplastique du lutoïde

Published
1997

22. Evidence for an Amiloride-Inhibited Mg2+/2H+ Antiporter in Lutoid (Vacuolar) Vesicles from Latex of Hevea brasiliensis1

Author

Amalou, Zakia, Gibrat, Rémy, Brugidou, Christophe, Trouslot, Pierre, and d'Auzac, Jean

Subjects
inorganic chemicals, Membranes and Bioenergetics
Abstract

Lutoids represent a lysosomal microvacuolar compartment of rubber-tree (Hevea brasiliensis) latex. We observed acidification of isolated vesicles after imposing an outward Mg(2+) diffusion gradient and dissipation of a preformed pH gradient in the presence of exogenous Mg(2+). These results suggest the presence of a Mg(2+)/H(+) antiporter. The maximum Mg(2+)/H(+) exchange rate was observed at pH 8.5. The K(m) values for Mg(2+) (2.6 mm) were identical for both influx and efflux experiments. When membrane potential was clamped at zero with K(+) and valinomycin, the response of the membrane potential probe oxonol VI showed that the Mg(2+)/H(+) exchange was electroneutral. Mg(2+)/H(+) exchange was inhibited by amiloride and imipramine. Both the inhibiting concentration range and the K(m) for Mg(2+) are similar to those reported for the Mg(2+)/2Na(+) antiporter in animals cell. These data are consistent with the existence of a Mg(2+)/2H(+) antiporter in a plant tonoplast.

Published
1992

26. Separation, Identification, and Profiling of Membrane Proteins by GFC/IEC/SDS-PAGE and MALDI TOF MS.

Author

Walker, John M., Thiellement, Hervé, Zivy, Michel, Damerval, Catherine, Méchin, Valérie, Szponarski, Wojciech, Delom, Frédéric, Sommerer, Nicolas, Rossignol, Michel, and Gibrat, Rémy

Abstract

Membrane protein identification by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) requires that proteins be separated prior to MS analysis. After membrane solubilization with the nondenaturing detergent n-dodecyl-β-d-maltoside, proteins can be separated by ion-exchange chromatography (IEC) and further resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). An additional separation step by gel filtration (GF) before IEC/SDS-PAGE can be required depending on the complexity of the membrane protein mixture. Staining of final SDS-PAGE gels allows one to establish simply the protein expression pattern of a membrane fraction and to profile responses. Moreover, in-gel digestion of hydrophobic integral proteins is valuable. Finally, the resolution capacity of this separation procedure allows identification of proteins by MALDI-TOF MS. The method is illustrated by application to plant and yeast plasma membrane and to plant vacuolar membrane. [ABSTRACT FROM AUTHOR]

Published
2007
Full Text
View/download PDF

36. Reconstitution of an electrogenic auxin transport activity mediated by Arabidopsis thalianaplasma membrane proteins

Author

Szponarski, Wojciech, Guibal, Olivier, Espuna, Meriam, Doumas, Patrick, Rossignol, Michel, and Gibrat, Rémy

Abstract

Plasma membrane proteins from Arabidopsis thalianaleaves were reconstituted into proteoliposomes and a K+diffusion potential was generated. The resulting ionic fluxes, determined in the presence of the plant hormone auxin (indole‐3 acetic acid), showed an additional electrogenic and saturable component, with a KMof 6 μM. This flux was neither detected in liposomes in the presence of indole‐3 acetic acid, nor in proteoliposomes in the presence of an inactive auxin analog and was completely inhibited by 3 μM naphtylphthalamic acid, a specific inhibitor of the auxin efflux carrier. The efficiency of the reconstituted carrier and the mechanism of its regulation by naphtylphthalamic acid are discussed.

Published
1999
Full Text
View/download PDF

37. Spontaneous insertion of plant plasma membrane (H+)ATPase into a preformed bilayer

Author

Simon-Plas, Françoise, Venema, Kees, Grouzis, Jean-Pierre, Gibrat, Rémy, Rigaud, Jacqueline, and Grignon, Claude

Abstract

Summary The purified (H+ATPase from corn roots plasma membrane inserted spontaneously into preformed bilayer from soybean lipids. The yield of the protein insertion, as measured from its H+-pumping activity, increased as a function of lipids and protein concentrations. In optimum conditions, all the (H+)ATPase molecules were closely associated with liposomes, exhibiting a high H+-pumping activity (150,000% quenching· min-1·mg-1 protein of the probe 9-amino-6-chloro-2-methoxyacridine). The insertion was achieved within a few seconds. No latency of the (H+)ATPase hydrolytic activity was revealed when lysophosphatidylcholine was added to permeabilize the vesicles. This indicated that the (H+)ATPase molecules inserted unidirectionally, the catalytic sites being exposed outside the vesicles (“inside-out” orientation), and thus freely accessible to Mg-ATP. The nondelipidated (H+)ATPase could also functionally insert into bilayer from PC:PE:PG or PC:PE:PI, due to the presence of both hydrophobic defects promoted by PE, and negative phospholipids specifically required by the (H+)ATPase from corn roots. The detergent octylglucoside facilitated the delipidated (H+)ATPase reinsertion probably by promoting both a proper protein conformation and hydrophobic defects in the bilayer. Lysophosphatidylcholine facilitated the delipidated protein insertion only when hydrophobic defects were already present, and thus seemed only capable to ensure a proper protein conformation

Published
1991
Full Text
View/download PDF

38. The Plant Inorganic Pyrophosphatase Does Not Transport K+in Vacuole Membrane Vesicles Multilabeled with Fluorescent Probes for H+, K+, and Membrane Potential (∗)

Author

Ros, Roc, Romieu, Charles, Gibrat, Rémy, and Grignon, Claude

Abstract

It has been claimed that the inorganic pyrophosphatase (PPase) of the plant vacuolar membrane transports K+in addition to H+in intact vacuoles (Davies, J. M., Poole, R. J., Rea, P. A., and Sanders, D.(1992) Proc. Natl. Acad. Sci. U. S. A. 89, 11701-11705). Since this was not confirmed using the purified and reconstituted PPase consisting of a 75-kDa polypeptide (Sato, M. H., Kasahara, M., Ishii, N., Homareda, H., Matsui, H., and Yoshida, M. (1994) J. Biol. Chem.269, 6725-6728), these authors proposed that K+transport by the PPase is dependent on its association with other membrane components lost during purification. We have examined the hypothesis of K+translocation by the PPase using native vacuolar membrane vesicles from Vitis viniferasuspension cells, multilabeled with fluorescent probes for K+, H+, and membrane potential. This material contained a high proportion of right-side-out, tightly sealed vesicles, exhibiting high PPase activity which was strongly stimulated by uncouplers and K+. Proton pumping occurred in response to pyrophosphate addition in the absence of K+. No K+incorporation into the vesicles could be observed after PPase energization in the presence of K+, although H+transport was highly stimulated. The hydrolytic activity was stimulated by a protonophore and by a H+/K+exchanger but not by the K+ionophore valinomycin. No evidence could be obtained supporting the operation of an endogenous K+/H+exchanger capable to dissipate the putative active K+flux generated by the PPase. We conclude that PPase in native vacuolar membrane vesicles does not transport K+.

Published
1995
Full Text
View/download PDF

39. Electrostatic analysis of effects of ions on the inhibition of corn root plasma membrane Mg-ATPase by the bivalent orthovanadate

Author

Gibrat, Rémy, Grouzis, J.P., Rigaud, Jade, Galtier, Nicolas, Grignon, C., Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
[SDV]Life Sciences [q-bio], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
1989

40. Transtonoplast potential difference and surface potential of isolated vacuoles

Author

Gibrat, Rémy, Barbier-Brygoo, H., Guern, J., Grignon, C., Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and B. Marin (Editeur)

Subjects
[SDV]Life Sciences [q-bio], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
1985

41. Preparation of Corn Root Plasmalemma with Low Mg-ATPase Latency and High Electrogenic H+ Pumping Activity after Phase Partitioning 1

Author

Galtier, Nathalie, Belver, Andres, Gibrat, Rémy, Grouzis, Jean-Pierre, Rigaud, Jacqueline, and Grignon, Claude

Subjects
Membranes and Bioenergetics
Abstract

Crude plasma membranes of corn (Zea mays L.) roots were obtained according to MI De Michelis and RM Spanswick (1986 Plant Physiol 81: 542-547). This preparation, which contained tightly sealed vesicles displaying Mg-ATP dependent H(+)-transport, was purified by phase partitioning. The percentage of inside-out vesicles (10%) was determined from the Mg-ATPase latency, revealed with lysophosphatidylcholine. A Triton X-100 treatment described previously (JP Grouzis, R Gibrat, J Rigaud, C Grignon 1987 Biochim Biophys Acta 903: 449-464) was applied to phase-partitioned plasma membranes. The percentage of catalytic sites freely accessible to Mg-ATP increased to 50% after Triton X-100 treatment. Treated vesicles remained capable of electrogenic H(+)-pumping, as demonstrated by Mg:ATP-dependent quinacrine fluorescence quenching and oxonol absorbance shift. As expected from the large increase of the catalytic sites accessibility, increases of the dye responses were observed. Concanavalin A binding was estimated from microelectrophoretic measurements of individual vesicles. Statistical analysis of concanavalin A binding and Mg-ATPase latency suggest that treated membranes have lost their asymmetric structure.

Published
1988

42. Membrane potential difference of isolated plant vacuoles: positive or negative? I Evidence for membrane binding of cationic probes

Author

Gibrat, Rémy, Barbier-Brygoo, H., Guern, J., Grignon, C., Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
[SDV]Life Sciences [q-bio], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
1985

43. Membrane potential difference of isolated plant vacuoles: positive or negative? II Comparison of measurements with microelectrodes and cationic probes

Author

Barbier-Brygoo, H., Gibrat, Rémy, Renaudin, J.P., Brown, Susan, Pradier, J.M., Grignon, C., Guern, J., Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
[SDV]Life Sciences [q-bio], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
1985

44. Electrstatic characteristics of corn root plasmalemma: effect on the Mg2+-ATPase activity

Author

Gibrat, Rémy, Grouzis, J.P., Rigaud, Jade, Grignon, C., Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
[SDV]Life Sciences [q-bio], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
1985

48. Characterization of the grapevine Shaker K + channel VvK3.1 supports its function in massive potassium fluxes necessary for berry potassium loading and pulvinus-actuated leaf movements.

Author

Nieves-Cordones M, Andrianteranagna M, Cuéllar T, Chérel I, Gibrat R, Boeglin M, Moreau B, Paris N, Verdeil JL, Zimmermann S, and Gaillard I

Subjects
Animals, Droughts, Flowers genetics, Flowers metabolism, Gene Expression Regulation, Plant, Hydrogen-Ion Concentration, Oocytes metabolism, RNA, Messenger genetics, RNA, Messenger metabolism, Stress, Physiological, Xenopus metabolism, Fruit metabolism, Plant Proteins metabolism, Potassium metabolism, Potassium Channels metabolism, Pulvinus metabolism, Vitis metabolism
Abstract

In grapevine, climate changes lead to increased berry potassium (K + ) contents that result in must with low acidity. Consequently, wines are becoming 'flat' to the taste, with poor organoleptic properties and low potential aging, resulting in significant economic loss. Precise investigation into the molecular determinants controlling berry K + accumulation during its development are only now emerging. Here, we report functional characterization by electrophysiology of a new grapevine Shaker-type K + channel, VvK3.1. The analysis of VvK3.1 expression patterns was performed by qPCR and in situ hybridization. We found that VvK3.1 belongs to the AKT2 channel phylogenetic branch and is a weakly rectifying channel, mediating both inward and outward K + currents. We showed that VvK3.1 is highly expressed in the phloem and in a unique structure located at the two ends of the petiole, identified as a pulvinus. From the onset of fruit ripening, all data support the role of the VvK3.1 channel in the massive K + fluxes from the phloem cell cytosol to the berry apoplast during berry K + loading. Moreover, the high amount of VvK3.1 transcripts detected in the pulvinus strongly suggests a role for this Shaker in the swelling and shrinking of motor cells involved in paraheliotropic leaf movements., (© 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.)

Published
2019
Full Text
View/download PDF

49. Separation, identification, and profiling of membrane proteins by GFC/IEC/SDS-PAGE and MALDI TOF MS.

Author

Szponarski W, Delom F, Sommerer N, Rossignol M, and Gibrat R

Subjects
Cell Fractionation, Chromatography, Gel methods, Chromatography, Ion Exchange methods, Databases, Protein, Electrophoresis, Polyacrylamide Gel methods, Gene Expression Profiling methods, Hydrophobic and Hydrophilic Interactions, Indicators and Reagents, Membrane Proteins chemistry, Plant Proteins chemistry, Plants chemistry, Solubility, Trypsin, Membrane Proteins analysis, Membrane Proteins isolation & purification, Plant Proteins analysis, Plant Proteins isolation & purification, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
Abstract

Membrane protein identification by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) requires that proteins be separated prior to MS analysis. After membrane solubilization with the nondenaturing detergent n-dodecyl-beta-D-maltoside, proteins can be separated by ion-exchange chromatography (IEC) and further resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). An additional separation step by gel filtration (GF) before IEC/SDS-PAGE can be required depending on the complexity of the membrane protein mixture. Staining of final SDS-PAGE gels allows one to establish simply the protein expression pattern of a membrane fraction and to profile responses. Moreover, in-gel digestion of hydrophobic integral proteins is valuable. Finally, the resolution capacity of this separation procedure allows identification of proteins by MALDI-TOF MS. The method is illustrated by application to plant and yeast plasma membrane and to plant vacuolar membrane.

Published
2007
Full Text
View/download PDF

50. The plasma membrane proteome of Saccharomyces cerevisiae and its response to the antifungal calcofluor.

Author

Delom F, Szponarski W, Sommerer N, Boyer JC, Bruneau JM, Rossignol M, and Gibrat R

Subjects
Cell Membrane metabolism, Electrophoresis, Polyacrylamide Gel, Saccharomyces cerevisiae drug effects, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Antifungal Agents pharmacology, Benzenesulfonates pharmacology, Membrane Proteins biosynthesis, Proteome biosynthesis, Saccharomyces cerevisiae metabolism, Saccharomyces cerevisiae Proteins biosynthesis
Abstract

Calcofluor is an antifungal compound known to induce structural perturbations of the cell wall by interfering with the synthesis of chitin microfibril. Proteins from a stripped plasma membrane fraction were solubilized with the neutral and non-denaturing detergent, the n-dodecyl beta-D-maltoside. Proteins were then resolved using a recently described ion-exchange chromatography (IEC)/lithium dodecyl sulfate (LDS)-PAGE procedure. Nearly 90 proteins were identified and clustered, based on their pI, molecular weight, abundance and/or hydrophobicity. This method was then applied to profile the plasma membrane response to calcofluor. The LDS-PAGE patterns obtained from whole plasma membrane proteins were similar for the non-treated and calcofluor-treated samples. However, IEC/LDS-PAGE analysis revealed subtle changes in the expression of several proteins of low abundance, in response to calcofluor. These proteins include Pil1p and Lsp1p, two sphingolipid long-chain base-responsive inhibitors of protein kinases involved in signaling pathways for cell wall integrity and Rho1p, a small GTPase. It was recently hypothesized that Pil1p and Lsp1p could associate with, and regulate, the plasma membrane beta-1-3-glucan synthase, responsible for the synthesis of another major microfibril for yeast cell wall. Results are discussed with respect to both calcofluor effects on the plasma membrane proteins and the power of the IEC/LDS-PAGE procedure in the search for new potential therapeutics targets.

Published
2006
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results