title: Identification of a pre-active conformation of a pentameric channel receptor.
abstract: Pentameric ligand-gated ion channels (pLGICs) mediate fast chemical signaling through global allosteric transitions. Despite the existence of several high-resolution structures of pLGICs, their dynamical properties remain elusive. Using the proton-gated channel GLIC, we engineered multiple fluorescent reporters, each incorporating a bimane and a tryptophan/tyrosine, whose close distance causes fluorescence quenching. We show that proton application causes a global compaction of the extracellular subunit interface, coupled to an outward motion of the M2-M3 loop near the channel gate. These movements are highly similar in lipid vesicles and detergent micelles. These reorganizations are essentially completed within 2 ms and occur without channel opening at low proton concentration, indicating that they report a pre-active intermediate state in the transition pathway toward activation. This provides a template to investigate the gating of eukaryotic neurotransmitter receptors, for which intermediate states also participate in activation.
authors.affiliation: Channel Receptors Unit, Institut Pasteur, Paris, France.|Unité Mixte de Recherche 3571, Centre National de la Recherche Scientifique, Paris, France.|Université Pierre et Marie Curie, Cellule Pasteur, Paris, France.
authors.forename: Anaïs
authors.identifier: 0000-0002-6044-4119
authors.initials: A
authors.lastname: Menny
authors.affiliation: Channel Receptors Unit, Institut Pasteur, Paris, France.|Unité Mixte de Recherche 3571, Centre National de la Recherche Scientifique, Paris, France.|Université Pierre et Marie Curie, Cellule Pasteur, Paris, France.
authors.forename: Solène N
authors.initials: SN
authors.lastname: Lefebvre
authors.affiliation: Departments of Anesthesiology, Physiology and Biophysics, Biochemistry, Weill Cornell Medicine, New York, United States.
authors.forename: Philipp Am
authors.initials: PA
authors.lastname: Schmidpeter
authors.affiliation: BioCIS, Université Paris-Sud, CNRS, Université Paris-Saclay, Châtenay-Malabry, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Drège
authors.affiliation: Unité de Dynamique Structurale des Macromolécules, Institut Pasteur, Paris, France.|Unité Mixte de Recherche 3528, Centre National de la Recherche Scientifique, Paris, France.
authors.forename: Zaineb
authors.initials: Z
authors.lastname: Fourati
authors.affiliation: Unité de Dynamique Structurale des Macromolécules, Institut Pasteur, Paris, France.|Unité Mixte de Recherche 3528, Centre National de la Recherche Scientifique, Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Delarue
authors.affiliation: Biologie Cellulaire de la Synapse, Institute of Biology, Ecole Normale Supérieure, Paris, France.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Edelstein
authors.affiliation: Departments of Anesthesiology, Physiology and Biophysics, Biochemistry, Weill Cornell Medicine, New York, United States.
authors.forename: Crina M
authors.initials: CM
authors.lastname: Nimigean
authors.affiliation: BioCIS, Université Paris-Sud, CNRS, Université Paris-Saclay, Châtenay-Malabry, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Joseph
authors.affiliation: Channel Receptors Unit, Institut Pasteur, Paris, France.|Unité Mixte de Recherche 3571, Centre National de la Recherche Scientifique, Paris, France.
authors.forename: Pierre-Jean
authors.identifier: 0000-0002-4770-430X
authors.initials: PJ
authors.lastname: Corringer
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D003001:Cloning, Molecular; D000458:Cyanobacteria / Q000737:chemistry* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D058446:Ligand-Gated Ion Channels / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008564:Membrane Potentials / Q000502:physiology; D008958:Models, Molecular; D009154:Mutation; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D018408:Patch-Clamp Techniques; D011485:Protein Binding; D000072756:Protein Conformation, alpha-Helical; D000072757:Protein Conformation, beta-Strand; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods; D014982:Xenopus laevis
chemical_list: D001426:Bacterial Proteins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D005456:Fluorescent Dyes; D058446:Ligand-Gated Ion Channels; D011994:Recombinant Proteins; C021149:bimanes
keywords: allostery; biophysics; fluorescence; ligand-gated ion channels; neuroscience; none; structural biology