This gene encodes an intracellular receptor for inositol 1,4,5-trisphosphate. Upon stimulation by inositol 1,4,5-trisphosphate, this receptor mediates calcium release from the endoplasmic reticulum. Mutations in this gene cause spinocerebellar ataxia type 15, a disease associated with an heterogeneous group of cerebellar disorders. Multiple transcript variants have been identified for this gene. [provided by RefSeq, Nov 2009],ACV, CLA4, INSP3R1, IP3R, IP3R1, PPP1R94, SCA15, SCA16, SCA29,B Cell Receptor Signaling Pathway,Calcium Signaling,Cancer,Endocrine & Metabolism,G protein signaling,Immunology & Inflammation,Neurodegenerative Diseases,Neuroscience,Phospholipase Signaling Pathway,Protein phosphorylation,Signal Transduction,T Cell Receptor Signaling Pathway,ITPR1