Stromal interaction molecule 1 (STIM1) is a transmembrane protein that is essential for store- operated Ca(2+) entry, a process of extracellular Ca(2+) influx in response to the depletion of Ca(2+) stores in the endoplasmic reticulum (ER). STIM1 localizes predominantly to the ER, upon Ca(2+) release from the ER, STIM1 translocates to the ER-plasma membrane junctions and activates Ca(2+) channels. Source: Recombinant protein corresponding to aa23-213 of human STIM1, fused to CaM-tag expressed in E. coli. Molecular Weight: ~38kD Amino Acid Sequence: MADQLTEEQI AEFKEAFSLF DKDGDGTITT KELGTVMRSL GQNPTEAELQ DMINEVDADG NGTIDFPEFL TMMARKMKDT DSEEEIREAF RVFDKDGNGY ISAAELRHVM TNLGEKLTDE EVDEMIREAD IDGDGQVNYE EFVQMMTAKG SMLSHSHSEK ATGTSSGANS EESTAAEFCR IDKPLCHSED EKLSFEAVRN IHKLMDDDAN GDVDVEESDE FLREDLNYHD PTVKHSTFHG EDKLISVEDL WKAWKSSEVY NWTVDEVVQW LITYVELPQY EETFRKLQLS GHAMPRLAVT NTTMTGTVLK MTDRSHRQKL QLKALDTVLF GPPLLTRHNH LKD Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.