Inositol 1,4,5-trisphosphate receptor 1 (IP3R1)

The Inositol 1,4,5-trisphosphate receptor 1 is a tetrameric intracellular Ca2+ channel located primarily on the membrane of the endoplasmic reticulum. Activated by binding inositol 1,4,5-trisphosphate (IP3), it enables Ca2+ release into the cytoplasm in response to diverse extracellular signals. IP3R1 channels are crucial for the spatiotemporal organization of intracellular Ca2+ signals that drive cellular responses such as apoptosis, autophagy, and proliferation. Structurally, IP3R1 consists of a large cytoplasmic domain (including the ligand-binding site), a transmembrane ion-conducting pore, and associated regulatory motifs that interact with proteins (e.g. Beclin 1, Bcl-2). Three major subtypes exist (IP3R1, IP3R2, IP3R3), each encoded by distinct genes. IP3R1 is highly expressed in nervous tissue and plays a key role in neuronal calcium signaling, as well as mediating crosstalk between cellular signaling pathways. Disruption of IP3R1 is implicated in neurodegeneration, cancer, and impaired cellular stress adaptation.

Other names

IP3R1InsP3R1ITPR1Type 1 inositol 1,4,5-trisphosphate receptorInositol trisphosphate receptor type 1

For antagonists: - Blockade of ligand-gated calcium release from the endoplasmic reticulum. - Inhibition of IP3 binding prevents Ca2+ release into the cytoplasm.