Figure 1. The angiotensin II signalling pathway.

The angiotensin II signalling pathway can signal through G-protein dependent and G-protein independent pathways. The angiotensin receptor (AT_1aR) is phosphorylated upon stimulation and G-proteins activated, which leads to an increase in IP3, intracellular calcium and diacyglycerol, which activates the signalling cascade involving several kinases e.g. PKC, MAPK and PKD. Phosphorylation of the receptor also leads to the recruitment of G-protein coupled receptor kinases and β-arrestin, and ultimately to internalisation of the receptor. Internalisation of the receptor yields the second wave of signalling, and has been associated with some of the positive effects of angiotensin II signalling in the cardiac setting.