At the plasma membrane, a group of phospholipase C (?PLC(bz))? proteins hydrolyse phosphatidylinositol 4,5 bisphosphate (PI(4,5)P2) to inositol 1,4,5 trisphosphate (I(1,4,5)P3) and diacylglycerol (DAG). This group of phospholipase C proteins lack a PH domain and so are is cytosolic. Their C2 domains bind to PI(4,5)P2 at the membrane. The PLC-beta proteins are thought to be responsible for the majority of PI(4,5)P2 hydrolysis.
The phospholipase C isoforms involved and their corresponding literature references are: phosphoinositide phospholipase C beta-1 (PLCB1) (Caricasole et al. 2000, Jhon et al. 1993, Park et al. 1992); beta-2 (PLCB2) (Jhon et al. 1993, Park et al. 1992); beta-3 (PLCB3) (Carozzi et al. 1992, Jhon et al. 1993); beta-4 (PLCB4) (Alvarez et al. 1995, Lee et al. 1993); and zeta-1 (PLCZ1) (Kouchi et al. 2005, Rogers et al. 2004).