Orai1 is a pore-forming calcium release-activated calcium (CRAC) channel subunit composed of four transmembrane domains []. Paralogues Orai2 and Orai3 have also been shown to be capable of forming CRAC channels and share Orai1 membrane topology. In these experiments, Orai-1, -2, and -3 channels were similarly inhibited by extracellular Ca2+. Orai3 channels seems to differ from Orai1 and -2 inbeing relatively resistant to the process of Ca2+ depotentiation []. However, the physiological roles of Orai2 and Orai3 in vivo are currently not well understood [].This entry represents Orai3.
Orai1 is a pore-forming calcium release-activated calcium (CRAC) channel subunit composed of four transmembrane domains []. Paralogues Orai2 and Orai3 have also been shown to be capable of forming CRAC channels and share Orai1 membrane topology. In these experiments, Orai-1, -2, and -3 channels were similarly inhibited by extracellular Ca2+. Orai3 channels seems to differ from Orai1 and -2 in being relatively resistant to the process of Ca2+ depotentiation []. However, the physiological roles of Orai2 and Orai3 in vivo are currently not well understood [].This entry represents Orai2.
This entry includes Drosophila Orai and human Orai1, Orai2 and Orai3. ORAI-1 green fluorescent protein (GFP) reporters are co-expressed with STIM-1 (ER CA(2+) sensors) in the gonad and intestine. The protein has four predicted transmembrane domains with a highly conserved region between TM2 ad TM3. This conserved domain is thought to function in channel regulation. ORAI1-related proteins are required for the production of the calcium channel, CRAC, along with STIM1-related proteins [].
This entry includes Drosophila Orai and human Orai1, Orai2 and Orai3. ORAI-1 green fluorescent protein (GFP) reporters are co-expressed with STIM-1 (ER CA(2+) sensors) in the gonad and intestine. The protein has four predicted transmembrane domains with a highly conserved region between TM2 ad TM3. This conserved domain is thought to function in channel regulation. ORAI1-related proteins are required for the production of the calcium channel, CRAC, along with STIM1-related proteins [].
