Abstract
STIM proteins are ubiquitous endoplasmic reticulum Ca(2+) sensors that rapidly translocate to couple with ‘store-operated’ Orai Ca(2+) channels when luminal Ca(2+) levels are low. STIM1 also senses heat changes, which trigger a similar translocation and prime STIM1 to activate Orai, suggesting that STIM1 functions as a sensor of multiple stress signals.