G_q protein (G_aq, or G_q/11) is a heterotrimeric G protein subunit that activates phospholipase C (PLC). PLC in turn hydrolyzes Phosphatidylinositol 4,5-bisphosphate (PIP₂) to diacyl glycerol (DAG) and inositol trisphosphate (IP₃) signal transduction pathway. DAG acts as a second messenger that activates Protein Kinase C (PKC) and IP₃ helps in phosphorylation of some proteins.