Dopamine 5 receptor mediates Ang II type 1 receptor degradation via a ubiquitin-proteasome pathway in mice and human cells
Hewang Li, … , Robin A. Felder, Pedro A. Jose
Hewang Li, … , Robin A. Felder, Pedro A. Jose
Published May 8, 2008
Citation Information: J Clin Invest. 2008;118(6):2180-2189. https://doi.org/10.1172/JCI33637.
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Research Article Cardiology

Dopamine 5 receptor mediates Ang II type 1 receptor degradation via a ubiquitin-proteasome pathway in mice and human cells

Abstract

Hypertension is a multigenic disorder in which abnormal counterregulation between dopamine and Ang II plays a role. Recent studies suggest that this counterregulation results, at least in part, from regulation of the expression of both the antihypertensive dopamine 5 receptor (D5R) and the prohypertensive Ang II type 1 receptor (AT1R). In this report, we investigated the in vivo and in vitro interaction between these GPCRs. Disruption of the gene encoding D5R in mice increased both blood pressure and AT1R protein expression, and the increase in blood pressure was reversed by AT1R blockade. Activation of D5R increased the degradation of glycosylated AT1R in proteasomes in HEK cells and human renal proximal tubule cells heterologously and endogenously expressing human AT1R and D5R. Confocal microscopy, Förster/fluorescence resonance energy transfer microscopy, and fluorescence lifetime imaging microscopy revealed that activation of D5R initiated ubiquitination of the glycosylated AT1R at the plasma membrane. The regulated degradation of AT1R via a ubiquitin/proteasome pathway by activation of D5R provides what we believe to be a novel mechanism whereby blood pressure can be regulated by the interaction of 2 counterregulatory GPCRs. Our results therefore suggest that treatments for hypertension might be optimized by designing compounds that can target the AT1R and the D5R.

Authors

Hewang Li, Ines Armando, Peiying Yu, Crisanto Escano, Susette C. Mueller, Laureano Asico, Annabelle Pascua, Quansheng Lu, Xiaoyan Wang, Van Anthony M. Villar, John E. Jones, Zheng Wang, Ammasi Periasamy, Yuen-Sum Lau, Patricio Soares-da-Silva, Karen Creswell, Gaétan Guillemette, David R. Sibley, Gilbert Eisner, Robin A. Felder, Pedro A. Jose

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Figure 1

Effect of the AT1R antagonist losartan on blood pressure and AT1R and renin protein expression in Drd5+/+ and Drd5–/– mice.

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Effect of the AT1R antagonist losartan on blood pressure and AT1R and re...
Vehicle (Veh) or losartan (Los) was administered via intraperitoneal injection every day for 5–7 days in 6-month-old mice. (A) Blood pressure was measured directly via the femoral artery under pentobarbital anesthesia. Losartan decreased blood pressure in Drd5–/– but not Drd5+/+ mice. SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure. n = 7. *P < 0.05 versus all other groups, factorial ANOVA, Holm-Sidak test. (B and C) Whole homogenates (30 μg) of kidneys isolated from A were electrophoresed (SDS-PAGE gel) and immunoblotted with anti-AT1R (B) or anti-renin (C) antibody. Amounts of glycosylated AT1R and renin proteins relative to actin were quantified by densitometry. The lanes for the renin blot were run on the same gel but were noncontiguous. n = 3–5. *P < 0.05 versus vehicle-treated Drd5+/+, factorial ANOVA, Holm-Sidak test. Data are mean ± SEM.