The production of the second messenger molecules diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) is mediated by activated phosphatidylinositol-specific phospholipase C enzymes (By similarity). Essential component of the phototransduction pathway (PubMed:2457447). Essential downstream component of a hh-signaling pathway which regulates the Duox-dependent gut immune response to bacterial uracil; required for the activation of Cad99C and consequently Cad99C-dependent endosome formation, which is essential for the Duox-dependent production of reactive oxygen species (ROS) in response to intestinal bacterial infection (PubMed:25639794). a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-4,5-bisphosphate) + H2O = 1D-myo-inositol 1,4,5-trisphosphate + a 1,2-diacyl-sn-glycerol + H(+) Interacts with inaD. Abundantly expressed in the adult retina. Flies have no photoreceptor potential, their eyes lack phospholipase C (PLC) activity and they are completely blind. 3D structural studies were performed with a synthetic heptapeptide that contained Cys, corresponding to position 1094, therefore the detected disulfide bridge is an artifact.