Inositol triphosphate

Inositol triphosphate (abbreviated InsP₃, also called triphosphoinositol), together with diacylglycerol, is a second messenger molecule used in signal transduction in biological cells. It is made by hydrolysis of phosphatidyl inositol, a phospholipid that is located in the plasma membrane, by phospholipase C.

Its main functions are to mobilize Ca²⁺ from storage organelles and to regulate cell proliferation and other cellular reactions. For example, in Drosophila, InsP₃ is used for intracellular transduction of light recognition in eye cells.