ORAI1 channel gating and selectivity is differentially altered by natural mutations in the first or third transmembrane domain.

ABSTRACT:

Key points

Gain-of-function mutations in the highly selective Ca²⁺ channel ORAI1 cause tubular aggregate myopathy (TAM) characterized by muscular pain, weakness and cramping. TAM-associated mutations in ORAI1 first and third transmembrane domain facilitate channel opening by STIM1, causing constitutive Ca²⁺ influx and increasing the currents evoked by Ca²⁺ store depletion. Mutation V107M additionally decreases the channel selectivity for Ca²⁺ ions and its inhibition by acidic pH, while mutation T184M does not alter the channel sensitivity to pH or to reactive oxygen species. The ORAI blocker GSK-7975A prevents the constitutive activity of TAM-associated channels and might be used in therapy for patients suffering from TAM.

Abstract

SUBMITTER: Bulla M 

PROVIDER: S-EPMC6332830 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature