Unmasking coupling between channel gating and ion permeation in the muscle nicotinic receptor.

ABSTRACT: Whether ion channel gating is independent of ion permeation has been an enduring, unresolved question. Here, applying single channel recording to the archetypal muscle nicotinic receptor, we unmask coupling between channel gating and ion permeation by structural perturbation of a conserved intramembrane salt bridge. A charge-neutralizing mutation suppresses channel gating, reduces unitary current amplitude, and increases fluctuations of the open channel current. Power spectra of the current fluctuations exhibit low- and high-frequency Lorentzian components, which increase in charge-neutralized mutant receptors. After aligning channel openings and closings at the time of transition, the average unitary current exhibits asymmetric relaxations just after channel opening and before channel clo

SUBMITTER: Strikwerda JR 

PROVIDER: S-EPMC8024024 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature