Angiotensin II is linked to which G protein in its signaling mechanism?

Angiotensin II primarily functions through the Gq protein in its signaling mechanism. When angiotensin II binds to its receptor, which is primarily the AT1 receptor, this interaction activates the Gq protein. Upon activation, Gq subsequently activates phospholipase C (PLC), which leads to the cleavage of phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol trisphosphate (IP3) and diacylglycerol (DAG).

The production of IP3 stimulates the release of calcium ions from the endoplasmic reticulum, while DAG activates protein kinase C (PKC), which then goes on to mediate various cellular responses. This pathway is crucial for many physiological processes such as vasoconstriction and the regulation of blood pressure.

Understanding the role of Gq protein in the signaling of angiotensin II is vital since it highlights how this hormone contributes to cardiovascular physiology and pathophysiology, including hypertension and heart failure.