Receptor biology

Following the Fate of Receptors

Science's STKE  13 Nov 2001:
Vol. 2001, Issue 108, pp. tw419-TW419
DOI: 10.1126/stke.2001.108.tw419

G protein-coupled receptors (GPCRs) are activated by ligand binding, but their signaling output is also regulated by receptor internalization and degradation. However, the mechanisms controlling the latter processes are incompletely understood. Shenoy et al. report that the Mdm2 protein, better known as the ubiquitin ligase that controls the abundance of the p53 tumor-suppressor protein, associates with β-arrestin. β-Arrestin appears to promote ubiquitination of the activated β2-adrenergic receptor, and ubiquitination of the receptor and β-arrestin each seem to have separate effects on receptor internalization and proteolysis. For example, in cells lacking Mdm2, ubiquitination of β-arrestin (but not that of the receptor) was lost, which resulted in decreased receptor internalization but had little effect on receptor degradation.

S. K. Shenoy, P. H. McDonald, T. A. Kohout, R. J. Lefkowitz, Regulation of receptor fate by ubiquitination of activated β2-adrenergic receptor and β-arrestin. Science 294, 1307-1313 (2001). [Abstract] [Full Text]