Ca(2+) release-activated Ca(2+) (CRAC) channel subunit which mediates Ca(2+) influx following depletion of intracellular Ca(2+) stores and channel activation by the Ca(2+) sensor, STIM1 (PubMed:16582901, PubMed:16645049, PubMed:16733527, PubMed:16766533, PubMed:16807233, PubMed:19249086, PubMed:23307288, PubMed:24351972, PubMed:24591628, PubMed:28219928, PubMed:20354224, PubMed:26956484). CRAC channels are the main pathway for Ca(2+) influx in T-cells and promote the immune response to pathogens by activating the transcription factor NFAT (PubMed:16582901). Plays a prominent role in Ca(2+) influx at the basolateral membrane of mammary epithelial cells independently of the Ca(2+) content of endoplasmic reticulum or Golgi stores. May mediate transepithelial transport of large quantities of Ca(2+) for milk secretion. Oxidation at Cys-195 leads to inactivation of channel activity. Interacts with STIM1 and STIM2; this regulates channel activity (PubMed:17905723, PubMed:19249086, PubMed:24351972, PubMed:28219928, PubMed:27185316, PubMed:30481768). Interacts with CALM; this may displace STIM1 and STIM2 and might thereby modulate channel activity (PubMed:23109337). Interacts with CRACR2A/EFCAB4B; the interaction is direct and takes place in absence of Ca(2+) (PubMed:20418871). Forms a complex with CRACR2A/EFCAB4B and STIM1 at low concentration of Ca(2+), the complex dissociates at elevated Ca(2+) concentrations. Interacts with ASPH (isoform 8) (PubMed:22586105). Interacts with SLC35G1 (PubMed:22084111). Interacts with UBQLN1 (PubMed:23307288). Interacts with ADCY8; interaction is calcium store depletion independent; interaction occurs in membrane raft; interaction increases markedly after store depletion; positively regulates SOCE-induced adenylate cyclase activity; contributes to the targeting of ADCY8 to discrete regions of the plasma membrane that are shielded from other calcium events (PubMed:22494970). Interacts with EFHB; the interaction takes place upon Ca(2+)-store depletion (PubMed:30481768). Interacts (via N- and C-termini) with ATP2C2 (via N-terminus); this interaction regulates Ca(2+) influx at the plasma membrane. Isoform beta is more mobile in the plasma membrane (PubMed:23307288). Colocalizes with STIM1 at the cell membrane (PubMed:27185316). Expressed in naive CD4 and CD8 T cells (at protein level) (PubMed:26956484). Expressed at similar levels in naive and effector T helper cells (PubMed:20354224). N-glycosylated (PubMed:19249086, PubMed:26956484). N-glycosylation inhibits channel activity in T cells (PubMed:26956484). Ubiquitinated. Cys-195 is oxidated, leading to inactivation of channel activity. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. In Greek mythology, the 'Orai' are the keepers of the gates of heaven: Eunomia (order or harmony), Dike (justice) and Eirene (peace). Belongs to the Orai family. According to a report, ORAI1 has been shown to colocalize with UBQLN1 in the autophagosome as a target for autophagic degradation; ORAI1 is however not an autophagosomal protein. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. ORAI1 mutation db