title: Illuminating the activation mechanisms and allosteric properties of metabotropic glutamate receptors.
abstract: In multimeric cell-surface receptors, the conformational changes of the extracellular ligand-binding domains (ECDs) associated with receptor activation remain largely unknown. This is the case for the dimeric metabotropic glutamate receptors even though a number of ECD structures have been solved. Here, using an innovative approach based on cell-surface labeling and FRET, we demonstrate that a reorientation of the ECDs is associated with receptor and G-protein activation. Our approach helps identify partial agonists and highlights allosteric interactions between the effector and binding domains. Any approach expected to stabilize the active conformation of the effector domain increased the agonist potency in stabilizing the active ECDs conformation. These data provide key information on the structural dynamics and drug action at metabotropic glutamate receptors and validate an approach for tackling such analysis on other receptors.
authors.affiliation: Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5203, Institut de Génomique Fonctionnelle, F-34000 Montpellier, France.
authors.forename: Etienne
authors.initials: E
authors.lastname: Doumazane
authors.forename: Pauline
authors.initials: P
authors.lastname: Scholler
authors.forename: Ludovic
authors.initials: L
authors.lastname: Fabre
authors.forename: Jurriaan M
authors.initials: JM
authors.lastname: Zwier
authors.forename: Eric
authors.initials: E
authors.lastname: Trinquet
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Pin
authors.forename: Philippe
authors.initials: P
authors.lastname: Rondard
mesh_terms: D000495:Allosteric Site; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D018360:Crystallography, X-Ray; D004252:DNA Mutational Analysis; D031541:Fluorescence Resonance Energy Transfer; D019204:GTP-Binding Proteins / Q000378:metabolism*; D018698:Glutamic Acid / Q000737:chemistry*; D057809:HEK293 Cells; D006801:Humans; D008024:Ligands; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D051381:Rats; D018094:Receptors, Metabotropic Glutamate / Q000737:chemistry*
chemical_list: D008024:Ligands; D018094:Receptors, Metabotropic Glutamate; D018698:Glutamic Acid; D019204:GTP-Binding Proteins; D002118:Calcium