title: Beta-arrestin 2 functions as a G-protein-coupled receptor-activated regulator of oncoprotein Mdm2.
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.
authors.affiliation: Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Gao
authors.forename: Yanxiang
authors.initials: Y
authors.lastname: Ni
authors.forename: Beibei
authors.initials: B
authors.lastname: Wang
authors.forename: Yalan
authors.initials: Y
authors.lastname: Wu
authors.forename: Lili
authors.initials: L
authors.lastname: Ji
authors.forename: Linhua
authors.initials: L
authors.lastname: Qin
authors.forename: Lan
authors.initials: L
authors.lastname: Ma
authors.forename: Gang
authors.initials: G
authors.lastname: Pei
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D019390:Arrestins / Q000502:physiology*; D001921:Brain / Q000196:embryology / Q000502:physiology; D002460:Cell Line; D018076:DNA, Complementary; D019204:GTP-Binding Proteins / Q000502:physiology*; D005786:Gene Expression Regulation; D015723:Gene Library; D006801:Humans; D007668:Kidney; D051379:Mice; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D051736:Proto-Oncogene Proteins c-mdm2; D011956:Receptors, Cell Surface / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism; D000071560:beta-Arrestin 2; D000071557:beta-Arrestins
chemical_list: C000605254:ARRB2 protein, human; C000605258:Arrb2 protein, mouse; D019390:Arrestins; D018076:DNA, Complementary; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D016159:Tumor Suppressor Protein p53; D025801:Ubiquitin; D000071560:beta-Arrestin 2; D000071557:beta-Arrestins; C497206:MDM2 protein, human; C497207:Mdm2 protein, mouse; D051736:Proto-Oncogene Proteins c-mdm2; D019204:GTP-Binding Proteins