Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Sci. Signal., 7 July 2009
Vol. 2, Issue 78, p. ra33
[DOI: 10.1126/scisignal.2000444]

RESEARCH

Oxygen-Regulated β2-Adrenergic Receptor Hydroxylation by EGLN3 and Ubiquitylation by pVHL

Liang Xie1, Kunhong Xiao1, Erin J. Whalen1, Michael T. Forrester2, Robert S. Freeman3, Guohua Fong4, Steven P. Gygi5, Robert J. Lefkowitz1,2,6, and Jonathan S. Stamler1,2*

1 Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
2 Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
3 Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14621, USA.
4 Center for Vascular Biology, University of Connecticut Health Center, Farmington, CT 06030, USA.
5 Department of Cell Biology, Harvard University Medical School, Boston, MA 02115, USA.
6 Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA.

Abstract: Agonist-induced ubiquitylation and degradation of heterotrimeric guanine nucleotide–binding protein (G protein)–coupled receptors (GPCRs) play an essential role in surface receptor homeostasis, thereby tuning many physiological processes. Although β-arrestin and affiliated E3 ligases mediate agonist-stimulated lysosomal degradation of the β2-adrenergic receptor (β2AR), a prototypic GPCR, the molecular cues that mark receptors for ubiquitylation and the regulation of receptor degradation by the proteasome remain poorly understood. We show that the von Hippel–Lindau tumor suppressor protein (pVHL)–E3 ligase complex, known for its regulation of hypoxia-inducible factor (HIF) proteins, interacts with and ubiquitylates the β2AR, thereby decreasing receptor abundance. We further show that the interaction of pVHL with β2AR is dependent on proline hydroxylation (proline-382 and -395) and that the dioxygenase EGLN3 interacts directly with the β2AR to serve as an endogenous β2AR prolyl hydroxylase. Under hypoxic conditions, receptor hydroxylation and subsequent ubiquitylation decrease dramatically, thus attenuating receptor degradation and down-regulation. Notably, in both cells and tissue, the abundance of endogenous β2AR is shown to reflect constitutive turnover by EGLN3 and pVHL. Our findings provide insight into GPCR regulation, broaden the functional scope of prolyl hydroxylation, and expand our understanding of the cellular response to hypoxia.

* To whom correspondence should be addressed. E-mail: staml001{at}mc.duke.edu

Citation: L. Xie, K. Xiao, E. J. Whalen, M. T. Forrester, R. S. Freeman, G. Fong, S. P. Gygi, R. J. Lefkowitz, J. S. Stamler, Oxygen-Regulated β2-Adrenergic Receptor Hydroxylation by EGLN3 and Ubiquitylation by pVHL. Sci. Signal. 2, ra33 (2009).

Read the Full Text

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Aiming Straight for the Heart: Prolyl Hydroxylases Set the BAR.
J. A. Garcia (2009)
Science Signaling 2, pe70
   Abstract »    Full Text »    PDF »

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882