1-Phosphatidylinositol-4,5-bisphosphate phosphodiesterase beta-3 is an enzyme that in humans is encoded by the PLCB3 gene. The gene codes for the enzyme phospholipase C β3. The enzyme catalyzes the formation of inositol 1,4,5-trisphosphate and diacylglycerol from phosphatidylinositol 4,5-bisphosphate. This reaction uses calcium as a cofactor and plays an important role in the intracellular transduction of many extracellular signals. This gene is activated by two G-protein alpha subunits, alpha-q and alpha-11, as well as G-beta gamma subunits. PLCB3 has been shown to interact with Sodium-hydrogen exchange regulatory cofactor 2.