D-myo-Inositol-1,3,4,5-tetraphosphate (sodium salt)

D-myo-Inositol-1,3,4,5-tetraphosphate (Ins (1,3,4,5) -P4) is formed by the phosphorylation of Ins (1,4,5) P3 by inositol 1,4,5-triphosphate 3-kinase. Ins (1,3,4,5) -P4 increases intracellular calcium levels by two distinct mechanisms: opening calcium channels on both the endoplasmic reticulum to release calcium from internal stores and on the plasma membrane to allow the influx of calcium from outside the cell.