D-myo-Inositol-4-phosphate (Ins(4)P1) is a member of the inositol phosphate (InsP) molecular family that plays a critical roles as small, soluble second messengers in the transmission of cellular signals.1,2 Ins(1,4,5)P3 is a second messenger produced in cells by phospholipase C (PLC)-mediated hydrolysis of phosphatidylinositol-4,5-diphosphate, and is the most studied of the InsP. Binding of Ins(1,4,5)P3 to its receptor on the endoplasmic reticulum results in the opening of calcium channels and an increase in intracellular calcium. Ins(4)P1 can be formed by dephosphorylation of Ins(1,4)P2 by inositol polyphosphate 1-phosphatase or dephosphorylated to inositol by inositol monophosphatase.
