Inositol 1,4,5‐trisphosphate (IP 3 ) receptors and their role in neuronal cell function

Inositol 1,4,5‐trisphosphate (IP 3 ) receptor is a Ca 2+ release channel localized on the endoplasmic reticulum (ER) and plays an important role in neuronal function. IP 3 receptor was discovered as a developmentally regulated protein missing in the cerebellar mutant mice. Recent studies indicate that IP 3 Rs are involved in early development and neuronal plasticity. IP 3 works to release IRBIT from the IP 3 binding core in addition to release Ca 2+ . IRBIT binds to and activates Na, Bicarbonate cotransporter. Electron microscopic study show the IP 3 receptor has allosteric property to change its form from square to windmill in the presence of Ca 2+ . IP 3 R associates with ERp44, a redox sensor, Homer, other proteins and is transported as vesicular ER on microtubules. All these data suggests IP 3 receptor/CA 2+ channel works as a signaling center inside cells.