ORAI3A gene on chromosome 16p11.2 that encodes a Ca2+ release-activated Ca2+ (CRAC) channel subunit, which mediates Ca2+ influx following depletion of intracellular Ca2+ stores and channel activation by the Ca2+ sensor, STIM1. CRAC channels are the main pathway for Ca2+ influx in T cells and promote an immune response to pathogens by activating the transcription factor NFAT. It is a key regulator of store-operated Ca(2+) channel.
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