Phosphorylation-mediated structural changes within the SOAR domain of stromal interaction molecule 1 enable specific activation of distinct Orai channels.

ABSTRACT: Low-conductance, highly calcium-selective channels formed by the Orai proteins exist as store-operated CRAC channels and store-independent, arachidonic acid-activated ARC channels. Both are activated by stromal interaction molecule 1 (STIM1), but CRAC channels are activated by STIM1 located in the endoplasmic reticulum membrane, whereas ARC channels are activated by the minor plasma membrane-associated pool of STIM1. Critically, maximally activated CRAC channel and ARC channel currents are completely additive within the same cell, and their selective activation results in their ability to each induce distinct cellular responses. We have previously shown that specific ARC channel activation requires a PKA-mediated phosphorylation of a single threonine residue (Thr³⁸⁹) within the

SUBMITTER: Thompson JL 

PROVIDER: S-EPMC5836120 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature