Ca/Calmodulin Binding to STIM1 Hydrophobic Residues Facilitates Slow Ca-Dependent Inactivation of the Orai1 Channel.

Background/aims: Store-operated Ca entry (SOCE) through plasma membrane Ca channel Orai1 is essential for many cellular processes. SOCE, activated by ER Ca store-depletion, relies on the gating function of STIM1 Orai1-activating region SOAR of the ER-anchored Ca-sensing protein STIM1. Electrophysiologically, SOCE is characterized as Ca release-activated Ca current (I).