Nedd4 mediates agonist-dependent ubiquitination, lysosomal targeting, and degradation of the beta2-adrenergic receptor.

ABSTRACT: Agonist-stimulated beta(2)-adrenergic receptor (beta(2)AR) ubiquitination is a major factor that governs both lysosomal trafficking and degradation of internalized receptors, but the identity of the E3 ubiquitin ligase regulating this process was unknown. Among the various catalytically inactive E3 ubiquitin ligase mutants that we tested, a dominant negative Nedd4 specifically inhibited isoproterenol-induced ubiquitination and degradation of the beta(2)AR in HEK-293 cells. Moreover, siRNA that down-regulates Nedd4 expression inhibited beta(2)AR ubiquitination and lysosomal degradation, whereas siRNA targeting the closely related E3 ligases Nedd4-2 or AIP4 did not. Interestingly, beta(2)AR as well as beta-arrestin2, the endocytic and signaling adaptor for the beta(2)AR, interact robustly wi

SUBMITTER: Shenoy SK 

PROVIDER: S-EPMC2494938 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature