Even though the protein has been identified earlier, its function was unknown until recently. In 2005, it was discovered that STIM1 functions as a calcium sensor in the endoplasmic reticulum.[5][6] Upon activation of the IP3 receptor, the calcium concentration in the endoplasmic reticulum decreases, which is sensed by STIM1, via its EF hand domain. STIM1 activates the "store-operated" ORAI1 calcium ion channels in the plasma membrane, via intracellular STIM1 movement, clustering under plasma membrane and protein protein interaction with ORAI isoforms.[7][8][9] STIM1-mediated calcium entry is required for thrombin-induced disassembly of VE-cadherinadherens junctions.[10]2-Aminoethoxydiphenyl borate (2-APB) and 4-chloro-3-ethylphenol (4-CEP) cause STIM1 clustering in a cell and prevent STIM1 moving toward plasma membrane.[11]
↑Parker NJ, Begley CG, Smith PJ, Fox RM (Oct 1996). "Molecular cloning of a novel human gene (D11S4896E) at chromosomal region 11p15.5". Genomics. 37 (2): 253–6. doi:10.1006/geno.1996.0553. PMID8921403.
↑Williams RT, Senior PV, Van Stekelenburg L, Layton JE, Smith PJ, Dziadek MA (Apr 2002). "Stromal interaction molecule 1 (STIM1), a transmembrane protein with growth suppressor activity, contains an extracellular SAM domain modified by N-linked glycosylation". Biochimica et Biophysica Acta. 1596 (1): 131–7. doi:10.1016/S0167-4838(02)00211-X. PMID11983428.
↑Soni D, Regmi SC, Wang DM, DebRoy A, Zhao YY, Vogel SM, Malik AB, Tiruppathi C (Apr 2017). "Pyk2 Phosphorylation of VE-PTP Downstream of STIM1 induced Ca2+ entry Regulates Disassembly of Adherens Junctions". American Journal of Physiology. Lung Cellular and Molecular Physiology. doi:10.1152/ajplung.00008.2017. PMID28385807.
↑Zeng B, Chen GL, Xu SZ (Oct 2012). "Store-independent pathways for cytosolic STIM1 clustering in the regulation of store-operated Ca(2+) influx". Biochemical Pharmacology. 84 (8): 1024–35. doi:10.1016/j.bcp.2012.07.013. PMID22842488.