Leu85 in the beta1-beta2 linker of ASIC1 slows activation and decreases the apparent proton affinity by stabilizing a closed conformation.

ABSTRACT: Acid-sensing ion channels (ASICs) are proton-activated channels expressed in neurons of the central and peripheral nervous systems where they modulate neuronal activity in response to external increases in proton concentration. The size of ASIC1 currents evoked by a given local acidification is determined by the number of channels in the plasma membrane and by the apparent proton affinities for activation and steady-state desensitization of the channel. Thus, the magnitude of the pH drop and the value of the baseline pH both are functionally important. Recent characterization of ASIC1s from an increasing number of species has made evident that proton affinities of these channels vary across vertebrates. We found that in species with high baseline plasma pH, e.g. frog, shark, and fish, ASIC

SUBMITTER: Li T 

PROVIDER: S-EPMC2903392 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature