Receptor for angiotensin II, a vasoconstricting peptide, which acts as a key regulator of blood pressure and sodium retention by the kidney (PubMed:7519446, PubMed:7688227). The activated receptor in turn couples to G-alpha proteins G(q) (GNAQ, GNA11, GNA14 or GNA15) and thus activates phospholipase C and increases the cytosolic Ca(2+) concentrations, which in turn triggers cellular responses such as stimulation of protein kinase C (By similarity). Expressed in lung, liver, kidney, and spleen, with highest expression in the heart. C-terminal Ser or Thr residues may be phosphorylated. Belongs to the G-protein coupled receptor 1 family.