STIM1: Proteins and Enzymes

STIM-1 (stromal interaction molecule 1), previously called GOK, is a 90 kDa type I transmembrane protein of the endoplasmic reticulum (ER). When STIM-1 senses depletion of calcium in the ER via its EF-hand domain, it interacts with the plasma membrane Ca2+ release-activated Ca2+ (CRAC) channel Orai1, increasing Ca2+ influx. Defects in STIM1 are the cause of immune dysfunction with T-cell inactivation due to calcium entry defect type 2 (IDTICED2).