Angiotensin II receptor type 2 or AT₂ is one of the receptors that bind the octapeptide hormone Angiotensin II (Ang II).

Ang II is the peptide hormone that generates most of the known effects of the renin-angiotensin system (RAS). Ang II is generated from the angiotensinogen protein by the actions of renin, angiotensin converting enzyme (ACE) and other peptidases. Ang II has a central role in cardiovascular homeostasis by regulating vasoconstriction, renal Na⁺ and water readsorption. In addition, Ang II induces cell growth and proliferation and has pro-inflammatory effects.

Most of the physiological actions of Ang II are mediated by AT₁ a member of the 7-transmembrane domain, G protein-coupled receptor (GPCR) superfamily. AT₂ is also a GPCR, and is largely believed to have counter-regulatory roles to the ones exerted through the AT₁ receptor. Hence, binding of Ang II to the AT₂ receptor will result in growth arrest and apoptosis, vasodilatation and hypotension.

Although the AT₂ receptor is structurally a member of the GPCR superfamily, the signaling mechanisms elicited following AT₂ receptor activation are not fully clarified. Recent evidence indicates that the AT₂ receptor signals through the G_ia2 and the G_ia3 proteins and through the activation of phosphotyrosine phosphatases such as  SHP-1.

AT₂ receptor distribution is more restricted than that of the AT₁ receptor. The highest expression levels of AT₂ have been found in the fetus, which is followed by a marked decrease shortly after birth. Nevertheless, significant AT₂ receptor expression can be detected in the heart, kidney, vascular endothelial cells and brain, among others.

Alomone Labs is pleased to offer a highly specific antibody directed against an extracellular epitope of the Angiotensin II Receptor Type-2. Anti-Angiotensin II Receptor Type-2 (extracellular) (#AAR-012) antibody can be used in western blot, immunocytochemistry and immunohistochemistry applications, and will recognize AT₂ receptor from rat and mouse samples.