A governance of ion selectivity based on the occupancy of the "beacon" in one- and four-domain calcium and sodium channels.

ABSTRACT: One of nature's exceptions was discovered when a Cav3 T-type channel was observed to switch phenotype from a calcium channel into a sodium channel by neutralizing an aspartate residue in the high field strength (HFS) +1 position within the ion selectivity filter. The HFS+1 site is dubbed a "beacon" for its location at the entryway just above the constricted, minimum radius of the HFS site's electronegative ring. A classification is proposed based on the occupancy of the HFS+1 "beacon" which correlates with the calcium- or sodium-selectivity phenotype. If the beacon is a glycine, or neutral, non-glycine residue, then the cation channel is calcium-selective or sodium-permeable, respectively (Class I). Occupancy of a beacon aspartate are calcium-selective channels

SUBMITTER: Spafford JD 

PROVIDER: S-EPMC10120453 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature