Q13586 

STIM1(Stromal interaction molecule 1) also konw as TAM1 is a type 1 transmembrane protein that mediates Ca2+ influx after depletion of intracellular Ca2+ stores by gating of store-operated Ca2+ influx channels (SOCs). STIM1 plays a significant role in mediating calcium influx, particularly following the depletion of intracellular calcium stores. Located primarily in the endoplasmic reticulum, STIM1 functions as a calcium sensor due to its EF-hand domain, which undergoes substantial conformational changes in response to fluctuating calcium levels. When intracellular calcium levels drop, STIM1 translocates to the plasma membrane, where STIM1 activates the calcium release-activated calcium (CRAC) channel subunit, TMEM142A/Orai1, facilitating the influx of calcium ions essential for various cellular processes, including secretion and transcription.