IP3 Type II Receptor (ITPR1) Antibody – Rabbit Polyclonal

This gene belongs to the Insp3 receptor family. It 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. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, Jul 2012]

IP3R1: a multi-pass endoplasmic reticulum membrane receptor for inositol 1,4,5-trisphosphate, a second messenger that mediates the release of intracellular calcium. Plays a role in ER stress-induced apoptosis. Cytoplasmic calcium released from the ER triggers apoptosis by the activation of CaMKII, eventually leading to the activation of downstream apoptosis pathways. Part of a cGMP kinase signaling complex that includes alpha-actin, calponin H1, phospholamban, PKG1 and IP3R1. Widely expressed. The receptor contains a calcium channel in its C-terminal extremity. Its large N-terminal cytoplasmic region has the ligand-binding site in the N-terminus and modulatory sites in the middle portion immediately upstream of the channel region. Phosphorylation by PKA prevents the ligand-induced opening of the calcium channels. Belongs to the ryanodine-inositol 1,4,5-triphosphate receptor ca(2+) channel (rir-cac) family. Eight alternatively spliced isoforms have been described.

Protein type: Membrane protein, multi-pass; Channel, calcium; Channel, ligand-gated; Membrane protein, integral

Cellular Component: endoplasmic reticulum membrane; protein complex; intracellular membrane-bound organelle; sarcoplasmic reticulum; cell; secretory granule membrane; endoplasmic reticulum; dendrite; postsynaptic density; integral to membrane; nuclear inner membrane; nuclear envelope; cytosol; calcineurin complex; lipid raft; cell soma; membrane; perinuclear region of cytoplasm; cytoplasm; plasma membrane; nucleolus; platelet dense granule membrane; intracellular

Molecular Function: protein C-terminus binding; protein binding; protein complex binding; calcium channel inhibitor activity; intracellular ligand-gated calcium channel activity; protein phosphatase binding; phosphoinositide binding; inositol 1,4,5-triphosphate-sensitive calcium-release channel activity

Biological Process: negative regulation of calcium-mediated signaling; elevation of cytosolic calcium ion concentration; endoplasmic reticulum calcium ion homeostasis; inositol phosphate-mediated signaling; voluntary musculoskeletal movement; calcium ion transport; release of sequestered calcium ion into cytosol; response to hypoxia; positive regulation of calcium ion transport; post-embryonic development