STIM protein coupling in the activation of Orai channels.

ABSTRACT: STIM proteins are sensors of endoplasmic reticulum (ER) luminal Ca(2+) changes and rapidly translocate into near plasma membrane (PM) junctions to activate Ca(2+) entry through the Orai family of highly Ca(2+)-selective "store-operated" channels (SOCs). Dissecting the STIM-Orai coupling process is restricted by the abstruse nature of the ER-PM junctional domain. To overcome this problem, we studied coupling by using STIM chimera and cytoplasmic C-terminal domains of STIM1 and STIM2 (S1ct and S2ct) and identifying a fundamental action of the powerful SOC modifier, 2-aminoethoxydiphenyl borate (2-APB), the mechanism of which has eluded recent scrutiny. We reveal that 2-APB induces profound, rapid, and direct interactions between S1ct or S2ct and Orai1, effecting full Ca(2+) release-activated

SUBMITTER: Wang Y 

PROVIDER: S-EPMC2678612 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature