Gq alpha subunit

G_q protein (G_αq, 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.

Function

G_q proteins are class of G proteins which work to activate phospholipase C (PLC), participating in a variety of cellular signaling pathways.

The G_q protein works by activating PLC. PLC then cleaves a phospholipid. In the process, phosphatidylinositol 4,5-bisphosphate (PIP2) is cleaved into diacyl glycerol (DAG) and inositol 1,4,5-trisphosphate (IP₃). DAG remains bound to the membrane, and IP₃ is released as a soluble structure into the cytosol. IP₃ then diffuses through the cytosol to bind to IP₃ receptors, particular calcium channels in the endoplasmic reticulum (ER). These channels are specific to calcium and only allow the passage of calcium to move through. This causes the cytosolic concentration of calcium to increase, causing a cascade of intracellular changes and activity.