Source:http://linkedlifedata.com/resource/umls/id/C0626645
NCI: Widely expressed by human ITPR1 Gene (InsP3R Family) as 8 potential alternative isoforms, 2758-aa 314-kDa integral endoplasmic reticulum membrane protein Inositol 1,4,5-Triphosphate Receptor Type 1 mediates release of intracellular calcium in response to second messenger inositol 1,4,5-trisphosphate. A likely homotetramer, the receptor contains 5 MIR domains, a large N-terminal ligand-binding cytoplasmic region, and central modulatory sites immediately upstream of the C-terminal calcium channel. Calcium appears to inhibit ligand binding to the receptor, perhaps by interaction with an inhibitory calcium-binding protein. Phosphorylation may prevent ligand-induced opening of the calcium channel. ITPR1 interacts with TRPC4 and is phosphorylated by c-AMP kinase. (NCI)