Ip3
Inositol 1,4,5-trisphosphate (IP3) is a cleavage product of phosphatidylinositol 4,5-bisphosphate (PIP2). PIP2 is a phospholipid molecule cleaved into inositol 1,4,5-trisphosphate and diacylglycerol (DAG) by hormone binding. Inositol 1,4,5-trisphosphate binds to IP3 receptor which results to the release of calcium from the calcium pumps.