Beta-arrestin 2 functions as a G-protein-coupled receptor-activated regulator of oncoprotein Mdm2

J Biol Chem. 2003 Feb 21;278(8):6363-70. doi: 10.1074/jbc.M210350200. Epub 2002 Dec 17.

Abstract

Oncoprotein Mdm2 is a master negative regulator of the tumor suppressor p53 and has been recently shown to regulate the ubiquitination of beta-arrestin 2, an important adapter and scaffold in signaling of G-protein-coupled receptors (GPCRs). However, whether beta-arrestin 2 has any effect on the function of Mdm2 is still unclear. Our current results demonstrated that the binding of Mdm2 to beta-arrestin 2 was significantly enhanced by stimulation of GPCRs. Activation of GPCRs led to formation of a ternary complex of Mdm2, beta-arrestin 2, and GPCRs and thus recruited Mdm2 to GPCRs at plasma membrane. Moreover, the binding of beta-arrestin 2 to Mdm2 suppressed the self-ubiquitination of Mdm2 and consequently reduced the Mdm2-mediated p53 degradation and ubiquitination. Further experiments revealed that overexpression of beta-arrestin 2 enhanced the p53-mediated apoptosis while suppression of endogenous beta-arrestin 2 expression by RNA interference technology considerably attenuated the p53-mediated apoptosis. Our study thus suggests that beta-arrestin 2 may serve as a cross-talk linker between GPCR and p53 signaling pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Arrestins / physiology*
  • Brain / embryology
  • Brain / physiology
  • Cell Line
  • DNA, Complementary
  • GTP-Binding Proteins / physiology*
  • Gene Expression Regulation*
  • Gene Library
  • Humans
  • Kidney
  • Mice
  • Nuclear Proteins*
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / physiology*
  • Proto-Oncogene Proteins c-mdm2
  • Receptors, Cell Surface / physiology*
  • Recombinant Proteins / metabolism
  • Transfection
  • Tumor Suppressor Protein p53 / metabolism
  • Ubiquitin / metabolism
  • beta-Arrestin 2
  • beta-Arrestins

Substances

  • ARRB2 protein, human
  • Arrb2 protein, mouse
  • Arrestins
  • DNA, Complementary
  • Nuclear Proteins
  • Proto-Oncogene Proteins
  • Receptors, Cell Surface
  • Recombinant Proteins
  • Tumor Suppressor Protein p53
  • Ubiquitin
  • beta-Arrestin 2
  • beta-Arrestins
  • MDM2 protein, human
  • Mdm2 protein, mouse
  • Proto-Oncogene Proteins c-mdm2
  • GTP-Binding Proteins