Mutational analysis to explore long-range allosteric couplings involved in a pentameric channel receptor pre-activation and activation.

ABSTRACT: Pentameric ligand-gated ion channels (pLGICs) mediate chemical signaling through a succession of allosteric transitions that are yet not completely understood as intermediate states remain poorly characterized by structural approaches. In a previous study on the prototypic bacterial proton-gated channel GLIC, we generated several fluorescent sensors of the protein conformation that report a fast transition to a pre-active state, which precedes the slower process of activation with pore opening. Here, we explored the phenotype of a series of allosteric mutations, using simultaneous steady-state fluorescence and electrophysiological measurements over a broad pH range. Our data, fitted to a three-state Monod-Wyman-Changeux model, show that mutations at the subunit interface in the extracellul

SUBMITTER: Lefebvre SN 

PROVIDER: S-EPMC8504973 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature