title: The angiotensin II AT2 receptor is an AT1 receptor antagonist.
abstract: The vasopressor angiotensin II activates AT(1) and AT(2) receptors. Most of the known in vivo effects of angiotensin II are mediated by AT(1) receptors while the biological functions of AT(2) receptors are less clear. We report here that the AT(2) receptor binds directly to the AT(1) receptor and thereby antagonizes the function of the AT(1) receptor. The AT(1)-specific antagonism of the AT(2) receptor was independent of AT(2) receptor activation and signaling, and it was effective on different cells and on human myometrial biopsies with AT(1)/AT(2) receptor expression. Thus, the AT(2) receptor is the first identified example of a G-protein-coupled receptor which acts as a receptor-specific antagonist.
authors.affiliation: Medical Research Center, Ain Shams University Hospital, Cairo, Egypt.
authors.forename: S
authors.initials: S
authors.lastname: AbdAlla
authors.forename: H
authors.initials: H
authors.lastname: Lother
authors.forename: A M
authors.initials: AM
authors.lastname: Abdel-tawab
authors.forename: U
authors.initials: U
authors.lastname: Quitterer
mesh_terms: D000804:Angiotensin II / Q000378:metabolism*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D019281:Dimerization; D005260:Female; D005333:Fetus / Q000166:cytology; D005347:Fibroblasts / Q000378:metabolism; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D007295:Inositol Phosphates / Q000096:biosynthesis; D008970:Molecular Weight; D009215:Myometrium / Q000378:metabolism; D016716:PC12 Cells; D011485:Protein Binding; D051381:Rats; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D057911:Angiotensin Receptor Antagonists; D007295:Inositol Phosphates; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin; D000804:Angiotensin II; D020962:Heterotrimeric GTP-Binding Proteins