(G)-protein-coupled receptor Mas is a physiological antagonist of the angiotensin II type 1 receptor

Article

关键词: RESONANCE ENERGY-TRANSFER;    PROTEIN-COUPLED RECEPTORS;    TRANSFER BRET;    OLIGOMERIZATION;    PROTOONCOGENE;    CELLS;    HETEROOLIGOMERS;    HETERODIMERS;    ACTIVATION;    SUBUNITS;   

DOI  :  10.1161/01.CIR.0000160867.23556.7D

来源: SCIE

【 摘 要 】

Background-We previously identified the G-protein-coupled receptor Mas, encoded by the Mas proto-oncogene, as an endogenous receptor for the heptapeptide angiotensin-(1-7); however, the receptor is also suggested to be involved in actions of angiotensin II. We therefore tested whether this could be mediated indirectly through an interaction with the angiotensin II type 1 receptor, AT(1). Methods and Results-In transfected mammalian cells, Mas was not activated by angiotensin II; however, AT1 receptor-mediated, angiotensin II-induced production of inositol phosphates and mobilization of intracellular Ca2+ was diminished by 50% after coexpression of Mas, despite a concomitant increase in angiotensin II binding capacity. Mas and the AT(1) receptor formed a constitutive hetero-oligomeric complex that was unaffected by the presence of agonists or antagonists of the 2 receptors. In vivo, Mas acts as an antagonist of the AT(1) receptor; mice lacking the Mas gene show enhanced angiotensin II-mediated vasoconstriction in mesenteric microvessels. Conclusions-These results demonstrate that Mas can hetero-oligomerize with the AT(1) receptor and by so doing inhibit the actions of angiotensin II. This is a novel demonstration that a G-protein-coupled receptor acts as a physiological antagonist of a previously characterized receptor. Consequently, the AT(1)-Mas complex could be of great importance as a target for pharmacological intervention in cardiovascular diseases.

【 授权许可】

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