Orai1 dimer STIM1 Dimer CRAC channel STIM1 activation of CRAC Authored: Akkerman, JW, 2009-09-04 Edited: Jupe, S, 2010-06-07 Pubmed16921385 Pubmed17703229 Pubmed17965774 Pubmed18187424 Pubmed18596693 Pubmed18769136 Pubmed18952890 Pubmed19249086 Reactome Database ID Release 43434700 Reactome, http://www.reactome.org ReactomeREACT_23904 Reviewed: Kunapuli, SP, 2010-06-07 Sustained calcium signalling in lymphocytes and platelets requires the uptake of extracellular calcium when intracellular stores are depleted. The process whereby intracellular calcium depletion stimulates calcium uptake is often referred to as Store-operated calcium entry (SOCE). Store depletion is sensed by stromal interaction molecule 1 (STIM1), which then translocates to the plasma membrane and associates with 2 dimers of Orai1 to form a calcium-release activated calcium (CRAC) channel. has a Stoichiometric coefficient of 2