Search

Your search keyword '"Thibaud, Jean-Baptiste"' showing total 14 results
Start Over Author "Thibaud, Jean-Baptiste" Database OpenAIRE
14 results on '"Thibaud, Jean-Baptiste"'

1. Heterogeneous expression of GABA receptor‐like subunits LCCH3 and GRD reveals functional diversity of GABA receptors in the honeybee Apis mellifera

Author

Van Dijk, Juliette, Henry, Christopher, Cens, Thierry, Charnet, Pierre, Cohen‐Solal, Catherine, Collet, Claude, van‐Dijk, Juliette, Guiramand, Janique, Jésus‐Ferreira, Marie‐céleste, Menard, Claudine, Mokrane, Nawfel, Roussel, Julien, Thibaud, Jean‐Baptiste, Vignes, Michel, Rousset, Matthieu, Institut des Biomolécules Max Mousseron [Pôle Chimie Balard] (IBMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Unité mixte de recherche Ecologie des invertébrés (UAPV), Institut National de la Recherche Agronomique (INRA)-Avignon Université (AU), Centre de recherche en Biologie Cellulaire (CRBM), Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Abeilles et Environnement (AE), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0301 basic medicine, Pharmacology, GABAA receptor, [SDV.BA]Life Sciences [q-bio]/Animal biology, [SDV]Life Sciences [q-bio], Xenopus, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Biology, biology.organism_classification, Research Papers, Cell biology, 03 medical and health sciences, 030104 developmental biology, 0302 clinical medicine, GABA receptor, Chloride channel, Homomeric, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Receptor, Gene, 030217 neurology & neurosurgery, ComputingMilieux_MISCELLANEOUS, Ionotropic effect
Abstract

International audience; Background and Purpose: Despite a growing awareness, annual losses of honeybee colonies worldwide continue to reach threatening levels for food safety and global biodiversity. Among the biotic and abiotic stresses probably responsible for these losses, pesticides, including those targeting ionotropic GABA receptors, are one of the major drivers. Most insect genomes include the ionotropic GABA receptor subunit gene, Rdl, and two GABA-like receptor subunit genes, Lcch3 and Grd. Most studies have focused on Rdl which forms homomeric GABA-gated chloride channels, and a complete analysis of all possible molecular combinations of GABA receptors is still lacking.Experimental Approach: We cloned the Rdl, Grd, and Lcch3 genes of Apis mellifera and systematically characterized the resulting GABA receptors expressed in Xenopus oocytes, using electrophysiological assays, fluorescence microscopy and coimmunoprecipitation techniques.Key Results: The cloned subunits interacted with each other, forming GABA-gated heteromeric channels with particular properties. Strikingly, these heteromers were always more sensitive than AmRDL homomer to all the pharmacological agents tested. In particular, when expressed together, Grd and Lcch3 form a non-selective cationic channel that opens at low concentrations of GABA and with sensitivity to insecticides similar to that of homomeric Rdl channels.Conclusion and Implications: For off-target species like the honeybee, chronic sublethal exposure to insecticides constitutes a major threat. At these concentration ranges, homomeric RDL receptors may not be the most pertinent target to study and other ionotropic GABA receptor subtypes should be considered in order to understand more fully the molecular mechanisms of sublethal toxicity to insecticides.

Published
2020

2. Are homomeric RDL receptors the only GABA receptors to be considered in Apis Mellifera ecotoxicity studies?

Author

Rousset, Matthieu, Charnet, Pierre, Cens, Thierry, Thibaud, Jean-Baptiste, Richardier, Arnaud, Laurent, Gabriel, Giraud, Lia, Charnet, Pierre, Institut des Biomolécules Max Mousseron [Pôle Chimie Balard] (IBMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure des Arts Décoratifs, Paris, École nationale supérieure des Arts Décoratifs (EnsAD), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
[SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, [SDV.BBM.BP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

3. Honeybee locomotion is impaired by Am-CaV3 low voltage-activated Ca(2+) channel antagonist

Author

Rousset, Matthieu, Collet, Claude, Cens, Thierry, Bastin, Florian, Raymond, Valérie, Massou, Isabelle, Menard, Claudine, Thibaud, Jean-Baptiste, Charreton, Mercedes, Vignes, Michel, Chahine, Mohamed, Sandoz, Jean-Christophe, Charnet, Pierre, Institut des Biomolécules Max Mousseron [Pôle Chimie Balard] (IBMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Abeilles et Environnement (AE), Institut National de la Recherche Agronomique (INRA)-Avignon Université (AU), Évolution, génomes, comportement et écologie (EGCE), Université Paris-Sud - Paris 11 (UP11)-IRD-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11), Institut de Recherche pour le Développement (IRD [France-Ouest]), Université Paris-Saclay, Signalisation Fonctionnelle des Canaux Ioniques et Récepteurs (SIFCIR), Université d'Angers (UA)-Institut National de la Recherche Agronomique (INRA), Centre de Recherches sur la Cognition Animale - UMR5169 (CRCA), Institut des sciences du cerveau de Toulouse. (ISCT), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre de Biologie Intégrative (CBI), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT), Centre de recherche de l’Institut universitaire en santé mentale de Québec [Canada] (CERVO), Département de réadaptation (Faculté de médecine de l'Université Laval) [Canada], Faculté de médecine de l'Université Laval [Québec] (ULaval), Université Laval [Québec] (ULaval)-Université Laval [Québec] (ULaval)-Faculté de médecine de l'Université Laval [Québec] (ULaval), Université Laval [Québec] (ULaval)-Université Laval [Québec] (ULaval), Evolution Génomes Comportement et Ecologie, ANR Bee- Channels N° ANR-13-BSV7-0010-0, Ecole Nationale Supérieure de Chimie de Montpellier, Institut National de la Recherche Agronomique (INRA)-Université d'Angers (UA), Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut des sciences du cerveau de Toulouse. (ISCT), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J)-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées, Faculté de médecine de l'Université Laval [Québec] (ULaval)-Faculté de médecine de l'Université Laval [Québec] (ULaval), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire en Santé Mentale de Québec, and Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)

Subjects
apis mellifera, xenopus oocyte, [SDV]Life Sciences [q-bio], canal calcique, hybridation in situ, in situ hybridization, bee, activation cellulaire, abeille, neurone récepteur, myocyte
Abstract

Voltage-gated Ca(2+) channels are key transducers of cellular excitability and participate in several crucial physiological responses. In vertebrates, 10 Ca(2+) channel genes, grouped in 3 families (CaV1, CaV2 and CaV3), have been described and characterized. Insects possess only one member of each family. These genes have been isolated in a limited number of species and very few have been characterized although, in addition to their crucial role, they may represent a collateral target for neurotoxic insecticides. We have isolated the 3 genes coding for the 3 Ca(2+) channels expressed in Apis mellifera. This work provides the first detailed characterization of the honeybee T-type CaV3 Ca(2+) channel and demonstrates the low toxicity of inhibiting this channel. Comparing Ca(2+) currents recorded in bee neurons and myocytes with Ca(2+) currents recorded in Xenopus oocytes expressing the honeybee CaV3 gene suggests native expression in bee muscle cells only. High-voltage activated Ca(2+) channels could be recorded in the somata of different cultured bee neurons. These functional data were confirmed by in situ hybridization, immunolocalization and in vivo analysis of the effects of a CaV3 inhibitor. The biophysical and pharmacological characterization and the tissue distribution of CaV3 suggest a role in honeybee muscle function.

Published
2017

4. CPK13, a Noncanonical Ca2+-Dependent Protein Kinase, Specifically Inhibits KAT2 and KAT1 Shaker K+ Channels and Reduces Stomatal Opening1[C][W]

Author

Ronzier, Elsa, Corratgé-Faillie, Claire, Sanchez, Frédéric, Prado, Karine, Brière, Christian, Leonhardt, Nathalie, Thibaud, Jean-Baptiste, and Xiong, Tou Cheu

Subjects
Xenopus laevis, Patch-Clamp Techniques, Microscopy, Fluorescence, Arabidopsis Proteins, Potassium Channels, Voltage-Gated, Plant Stomata, Arabidopsis, Animals, Calcium, Articles, Phosphorylation, Potassium Channels, Inwardly Rectifying, Protein Kinases
Abstract

Ca(2) (+)-dependent protein kinases (CPKs) form a large family of 34 genes in Arabidopsis (Arabidopsis thaliana). Based on their dependence on Ca(2+), CPKs can be sorted into three types: strictly Ca(2+)-dependent CPKs, Ca(2+)-stimulated CPKs (with a significant basal activity in the absence of Ca(2+)), and essentially calcium-insensitive CPKs. Here, we report on the third type of CPK, CPK13, which is expressed in guard cells but whose role is still unknown. We confirm the expression of CPK13 in Arabidopsis guard cells, and we show that its overexpression inhibits light-induced stomatal opening. We combine several approaches to identify a guard cell-expressed target. We provide evidence that CPK13 (1) specifically phosphorylates peptide arrays featuring Arabidopsis K(+) Channel KAT2 and KAT1 polypeptides, (2) inhibits KAT2 and/or KAT1 when expressed in Xenopus laevis oocytes, and (3) closely interacts in plant cells with KAT2 channels (Förster resonance energy transfer-fluorescence lifetime imaging microscopy). We propose that CPK13 reduces stomatal aperture through its inhibition of the guard cell-expressed KAT2 and KAT1 channels.

Published
2014

5. Molecular basis for modulation of voltage-gating of plant Shaker channels. Identification of Ca2+-dependant kinasestargeting some Arabidopsis Shaker channels

Author

Pascaud, François, Held, Katrin, Moreau, Bertrand, Cherel, Isabelle, Lacombe, Benoit, Kudla, Jörg, Thibaud, Jean-Baptiste, 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), Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster (WWU), and Chérel, Isabelle

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

International audience

Published
2008

6. Increased functional diversity of plant K+ channels by preferential heteromerization

Author

Xicluna, Jerome, Lacombe, Benoît, Dreyer, Ingo, Alcon, Carine, Jeanguenin, Linda, Sentenac, Herve, Thibaud, Jean-Baptiste, and Chérel, Isabelle

Subjects
BIOLOGIE DU DEVELOPPEMENT, CANAL POTASSIQUE DE TYPE SHAKER, arabidopsis, membrane cellulaire, xenope, expression génique, séquence nucleique, potassium, embryonic structures, phloème, transport cationique, hormones, hormone substitutes, and hormone antagonists
Abstract

Assembly of plant Shaker subunits as heterotetramers, increasing channel functional diversity, has been reported. Here we focus on a new interaction, between AKT2 and KAT2 subunits. The assembly as AKT2/KAT2 heterotetramers is demonstrated by (i) a strong signal in two-hybrid tests with intracytoplasmic C-terminal regions, (ii) the effect of KAT2 on AKT2 subunit targeting in tobacco cells, (iii) the complete inhibition of AKT2 currents by co-expression with a dominant-negative KAT2 subunit in Xenopus oocytes, and reciprocally, and (iv) the appearance, upon co-expression of wild-type AKT2 and KAT2 subunits, of new channel functional properties that cannot be explained by the co-existence of two kinds of homotetrameric channels. In particular, the instantaneous current, characteristic of AKT2, displayed new functional features when compared with those of AKT2 homotetramers: activation by external acidification (instead of inhibition) and weak inhibition by calcium. Single channel current measurements in oocytes co-expressing AKT2 and KAT2 revealed a strong preference for incorporation of subunits into heteromultimers and a diversity of individual channels. In planta, these new channels, which may undergo specific regulations, are likely to be formed in guard cells and in the phloem, where they could participate in the control of membrane potential and potassium fluxes.

Published
2007

7. Arabidopsis shaker channel posttranslational regulation: search for proteins interacting with shaker alpha subunits

Author

Pascaud, François, Cherel, Isabelle, Lacombe, Benoit, Moreau, Bertrand, Thibaud, Jean-Baptiste, 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
2007

8. Plant Kin and Kout channels: Approaching the trait of opposite 3 rectification by analyzing more than 250 KAT1–SKOR chimeras

Author

Porée, Fabien, Wulfetange, Klaas, Naso, Alessia, Carpaneto, Armando, Roller, Anja, Natura, Gabriel, Bertl, Adam, Sentenac, Hervé, Thibaud, Jean-Baptiste, Dreyer, Ingo, 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), Institut fur Biochemie und Biologie, Molekularbiologie (UP), Universität Potsdam, Max Planck Institute of Molecular Plant Physiology (MPI-MP), Max-Planck-Gesellschaft, Istituto di Biofisica [Genova], Consiglio Nazionale delle Ricerche (CNR), Botanisches Institut [Karlsruhe], Universität Karlsruhe (TH), 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
Site-directed mutagenesis, [SDV.OT]Life Sciences [q-bio]/Other [q-bio.OT], Chimera, Yeast complementation, Rectification, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Potassium channel
Abstract

Members of the Shaker-like plant K+ channel family share a common structure, but are highly diverse in their function: they behave as either hyperpolarization-activated inward-rectifying (Kin) channels, or leak-like (Kweak) channels, or depolarization-activated outward-rectifying (Kout) channels. Here we created 256 chimeras between the Kin channel KAT1 and the Kout channel SKOR. The chimeras were screened in a potassium-uptake de.cient yeast strain to identify those, which mediate potassium inward currents, i.e., which are functionally equivalent to KAT1. This strategy allowed us to identify three chimeras which di.er from KAT1 in three parts of the polypeptide: the cytosolic N-terminus, the cytosolic C-terminus, and the putative voltage-sensor S4. Additionally, mutations in the Kout channel SKOR were generated in order to localize molecular entities underlying its depolarization activation. The triple mutant SKOR-D312N-M313L-I314G, carrying amino-acid changes in the S6 segment, was identied as a channel which did not display any recti.cation in the tested voltage-range.

Published
2005

9. Inward rectification of the AKT2 channel abolished by voltage-dependent phosphorylation

Author

Michard, E., Dreyer, I., Lacombe, Benoît, Sentenac, Hervé, Thibaud, J.B., Thibaud, Jean-Baptiste, Instituto, Gulbenkian de Ciencia, Institut fur Biochemie und Biologie, Molekularbiologie (UP), Universität Potsdam, 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
mesophyll-cells, [SDV.OT]Life Sciences [q-bio]/Other [q-bio.OT], post-translational regulation, localized k+ channel, potassium, protein-kinase, ion channels, plasma-membrane, arabidopsis-thaliana, abscisic-acid, xenopus oocytes, shaker, embryonic structures, gating, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, protein kinase A, phosphatasein rectifying potassium channel, guard-cells, hormones, hormone substitutes, and hormone antagonists
Abstract

The Arabidopsis K+ channel AKT2 possesses the remarkable property that its voltage threshold for activation can be either within the physiological range (gating mode 1), or shifted towards considerably more positive voltages (gating mode 2). Gating mode 1 AKT2 channels behave as delayed K+-selective inward rectifiers; while gating mode 2 AKT2 channels are K+-selective `open leaks' in the physiological range of membrane potential. In the present study we have investigated modulation of AKT2 current by effectors of phosphatases/ kinases in COS cells and Xenopus oocytes. These experiments show that (i) dephosphorylation can result in AKT2 channel silencing; and (ii) phosphorylation by protein kinase A (PKA) favors both recruitment of silenced AKT2 channels and transition from gating mode 1 to gating mode 2. Interestingly, phosphorylation of AKT2 by PKA in COS cells and Xenopus oocytes is favored by hyperpolarization. Two PKA phosphorylation sites (S210 and S329) were pinpointed in the region of the pore inner mouth. The role of these phosphorylation sites in the switch between the two gating modes was assessed by electrophysiological characterization of mutant channels. The molecular aspects of AKT2 regulation by phosphorylation, and the possible physiological meaning of such regulation in the plant context, are discussed.

Published
2005

10. Plant K-in and K-out channels : Approaching the trait of opposite rectification by analyzing more than 250 KAT1- SKOR chimeras

Author

Poree, Fabien, Wulfetange, K., Naso, A., Carpaneto, Armando, Roller, A., Natura, G., Bertl, Adam, Sentenac, H., Thibaud, Jean-Baptiste, and Dreyer, Ingo

Subjects
Institut für Biochemie und Biologie
Abstract

Members of the Shaker-like plant K+ channel family share a common structure, but are highly diverse in their function: they behave as either hyperpolarization-activated inward-rectifying (K-in) channels, or leak-like (K-weak) channels, or depolarization-activated outward-rectifying (K-out) channels. Here we created 256 chimeras between the K-in channel KAT1 and the K-out channel SKOR. The chimeras were screened in a potassium-uptake deficient yeast strain to identify those, which mediate potassium inward currents, i.e., which are functionally equivalent to KAT1. This strategy allowed Lis to identify three chimeras which differ from KAT1 in three parts of the polypeptide: the cytosolic N- terminus, the cytosolic C-terminus, and the putative voltage-sensor S4. Additionally, mutations in the K-out Channel SKOR were generated in order to localize molecular entities underlying its depolarization activation. The triple mutant SKOR-D312N-M313L-1314G, carrying amino-acid changes in the S6 segment, was identified as a channel which did not display any rectification in the tested voltage-range. (C) 2005 Elsevier Inc. All rights reserved

Published
2005

11. Assembly of plant Shaker-like K-out channels requires two distinct sites of the channel alpha-subunit

Author

Dreyer, Ingo, Poree, Fabien, Schneider, A., Mittelstadt, J., Bertl, Adam, Sentenac, H., Thibaud, Jean-Baptiste, and Müller-Röber, Bernd (Prof. Dr.)

Subjects
Institut für Biochemie und Biologie
Abstract

SKOR and GORK are outward-rectifying plant potassium channels from Arabidopsis thaliana. They belong to the Shaker superfamily of voltage-dependent K+ channels. Channels of this class are composed of four alpha-subunits and subunit assembly is a prerequisite for channel function. In this study the assembly mechanism of SKOR was investigated using the yeast two-hybrid system and functional assays in Xenopus oocytes and in yeast. We demonstrate that SKOR and GORK physically interact and assemble into heteromeric K-out channels. Deletion mutants and chimeric proteins generated from SKOR and the K-in channel alpha-subunit KAT1 revealed that the cytoplasmic C-terminus of SKOR determines channel assembly. Two domains thatchannel a-subunit KAT1 revealed that the cytoplasmic C-terminus of SKOR determines channel assembly. Two domains that are crucial for channel assembly were identified: i), a proximal interacting region comprising a putative cyclic nucleotide-binding domain together with 33 amino acids just upstream of this domain, and ii), a distal interacting region showing some resemblance to the K-T domain of KAT1. Both regions contributed differently to channel assembly. Whereas the proximal interacting region was found to be active on its own, the distal interacting region required an intact proximal interacting region to be active. K-out alpha-subunits did not assemble with K-in alpha-subunits because of the absence of interaction between their assembly sites

Published
2004

12. Search for protein partners interacting with guard cell Shaker channels

Author

Xicluna, Jérôme, Vartanian, Mathieu, Omrane, Selim, Lacombe, Benoît, Thibaud, Jean-Baptiste, Sentenac, Herve, Cherel, Isabelle, 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), BIOlogie et GEstion des Risques en agriculture (BIOGER), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, and Chérel, Isabelle

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

International audience

Published
2004

13. Magnesium ions promote assembly of channel-like structures from beticolin o, a non-peptide fungal toxin purified from Cercospora beticola

Author

Goudet, Cyril, Véry, Anne-Aliénor, Milat, M.L., Ildefonse, M., Thibaud, Jean-Baptiste, Sentenac, Herve, Blein, J.P., Unité de biochimie et biologie moléculaire des céréales, Institut National de la Recherche Agronomique (INRA), 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), Phytopharmacie et Biochimie des Iteractions Cellulaires (PBIC), and Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-Etablissement National d'Enseignement Supérieur Agronomique de Dijon (ENESAD)

Subjects
[SDV.GEN.GPL]Life Sciences [q-bio]/Genetics/Plants genetics, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
1998

14. The baculovirus/insect cell system as an alternative to Xenopus oocytes. First characterization of the AKT1 K+ channel from Arabidopsis thaliana

Author

Gaymard, Frédéric, Cerutti, Martine, Horeau, Christèle, Lemaillet, Guy, Urbach, Serge, Ravallec, Marc, Devauchelle, Gerard, Sentenac, Herve, Thibaud, Jean-Baptiste, 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), Unité mixte de recherche de pathologie comparée, Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de la Recherche Agronomique (INRA), and Centre National de la Recherche Scientifique (CNRS)

Subjects
polypeptide, potassium, arabidopsis thaliana, xenopus, membrane cellulaire, INSECTE, baculovirus, électrophysiologie, protéine, conductivité électrique, plante modèle, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], oocyte, expression des gènes
Abstract

8 graph.; International audience

Published
1996

Catalog

Books, media, physical & digital resources
See catalog results