Phosphoinositide-specific phospholipase C (PLC) plays a crucial role in the initiation of receptor mediated signal transduction through the generation of the two second messengers, inositol 1,4,5-triphosphate and diacylglycerol from phosphatidylinositol 4,5-bisphosphate. There are many mammalian PLC isozymes, including PLC β1, PLC β2, PLC β3, PLC β4, PLC γ1, PLC γ2, PLC δ1, PLC δ2 and PLC ε). PLC βs are the only PLC isforms that are regulated by G protein subunits and are activated by a heterotrimeric GTP-binding protein linked to various cell surface receptors. Two alternatively spliced forms (1181 and 1166 amino acids) of PLC β2 are generated in haematopoietic cells that differ in the carboxyl-terminal sequence implicated in interaction of PLC β enzymes with G αq. The Pleckstrin homology domain of PLC β2 is required for its targeting to the membrane and for substrate hydrolysis and its linker region exerts an inhibitory effect on basal PLC β2 activity. PLC β2 plays a major role in platelet activation and is mainly expressed in the periphery of the islet and acinar cells in rat pancreas