IP3R3/ITPR3 (F3L2A) Rabbit Monoclonal Antibody #85303

Inositol 1,4,5-trisphosphate receptors (IP3Rs) are multi-transmembrane Ca2+ release channels located predominantly in the endoplasmic reticulum (ER) of all cell types (1,2). There are three distinct isoforms of IP3Rs in mammalian cells, IP3R1, IP3R2, and IP3R3, encoded by genes ITPR1, ITPR2, and ITPR3, respectively (3). Each isoform exhibits a distinct expression pattern. IP3R1 is highly expressed in neurons, IP3R2 in cardiomyocytes and hepatocytes, and IP3R3 in rapidly proliferating cultured cells (4). IP3R3 is activated mainly by IP3-binding due to increased intracellular IP3 levels. Its Ca2+ releasing function is also regulated by other mechanisms, including intracellular Ca2+ levels, ATP levels, Akt-dependent C-terminal phosphorylation, interaction with Bcl-2 or G protein-coupled receptor kinase-interacting proteins 1 and 2 (5). IP3R3 plays important roles in various diseases, including cancer and neurological disorders (6). Depending on the cancer type and cellular context, the protein can act as an oncogene or tumor suppressor (7-9). By controlling Ca2+ release, the protein promotes insulin secretion in pancreatic beta cells and fluid secretion in salivary gland acini (10-12).