MARCH2 promotes endocytosis and lysosomal sorting of carvedilol-bound β(2)-adrenergic receptors.

Published

Journal Article

Lysosomal degradation of ubiquitinated β(2)-adrenergic receptors (β(2)ARs) serves as a major mechanism of long-term desensitization in response to prolonged agonist stimulation. Surprisingly, the βAR antagonist carvedilol also induced ubiquitination and lysosomal trafficking of both endogenously expressed β(2)ARs in vascular smooth muscle cells (VSMCs) and overexpressed Flag-β(2)ARs in HEK-293 cells. Carvedilol prevented β(2)AR recycling, blocked recruitment of Nedd4 E3 ligase, and promoted the dissociation of the deubiquitinases USP20 and USP33. Using proteomics approaches (liquid chromatography-tandem mass spectrometry), we identified that the E3 ligase MARCH2 interacted with carvedilol-bound β(2)AR. The association of MARCH2 with internalized β(2)ARs was stabilized by carvedilol and did not involve β-arrestin. Small interfering RNA-mediated down-regulation of MARCH2 ablated carvedilol-induced ubiquitination, endocytosis, and degradation of endogenous β(2)ARs in VSMCs. These findings strongly suggest that specific ligands recruit distinct E3 ligase machineries to activated cell surface receptors and direct their intracellular itinerary. In response to β blocker therapy with carvedilol, MARCH2 E3 ligase activity regulates cell surface β(2)AR expression and, consequently, its signaling.

Full Text

Duke Authors

Cited Authors

  • Han, S-O; Xiao, K; Kim, J; Wu, J-H; Wisler, JW; Nakamura, N; Freedman, NJ; Shenoy, SK

Published Date

  • November 26, 2012

Published In

Volume / Issue

  • 199 / 5

Start / End Page

  • 817 - 830

PubMed ID

  • 23166351

Pubmed Central ID

  • 23166351

Electronic International Standard Serial Number (EISSN)

  • 1540-8140

Digital Object Identifier (DOI)

  • 10.1083/jcb.201208192

Language

  • eng

Conference Location

  • United States