G_q alpha subunit

G_q protein alpha subunit is a family of heterotrimeric G protein alpha subunits. This family is also commonly called the G_q/11 (G_q/G₁₁) family or G_q/11/14/15 family to include closely related family members. G alpha subunits may be referred to as G_q alpha, G_αq, or G_qα. G_q proteins couple to G protein-coupled receptors to activate beta-type phospholipase C (PLC-β) enzymes. PLC-β in turn hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP₂) to diacyl glycerol (DAG) and inositol trisphosphate (IP₃). IP₃ acts as a second messenger to release stored calcium into the cytoplasm, while DAG acts as a second messenger that activates protein kinase C (PKC).