Plays a role in mediating store-operated Ca(2+) entry (SOCE), a Ca(2+) influx following depletion of intracellular Ca(2+) stores. Acts as Ca(2+) sensor in the endoplasmic reticulum via its EF-hand domain. Upon Ca(2+) depletion, translocates from the endoplasmic reticulum to the plasma membrane where it activates the Ca(2+) release-activated Ca(2+) (CRAC) channel subunit, TMEM142A/ORAI1. Forms homooligomers and heterooligomers with STIM2. Interacts with ORAI1. Interacts with MAPRE1; probably required for targeting to the growing microtubule plus ends. Interacts with EFCAB4B/CRACR2A; the interaction is direct and takes place in absence of Ca(2+). Forms a complex with EFCAB4B/CRACR2A and ORAI1 at low concentration of Ca(2+), the complex dissociates at elevated Ca(2+) concentrations. Interacts with TMEM66/SARAF, promoting a slow inactivation of STIM1-dependent SOCE activity, possibly by facilitating the deoligomerization of STIM1. Ubiquitously expressed in various human primary cells and tumor cell lines. Note: This description may include information from UniProtKB.
Protein type: Calcium-binding; Endoplasmic reticulum; Membrane protein, integral