title: A Non-Canonical Function of Gβ as a Subunit of E3 Ligase in Targeting GRK2 Ubiquitylation.
abstract: G protein-coupled receptors (GPCRs) comprise the largest family of cell surface receptors, regulate a wide range of physiological processes, and are the major targets of pharmaceutical drugs. Canonical signaling from GPCRs is relayed to intracellular effector proteins by trimeric G proteins, composed of α, β, and γ subunits (Gαβγ). Here, we report that G protein β subunits (Gβ) bind to DDB1 and that Gβ2 targets GRK2 for ubiquitylation by the DDB1-CUL4A-ROC1 ubiquitin ligase. Activation of GPCR results in PKA-mediated phosphorylation of DDB1 at Ser645 and its dissociation from Gβ2, leading to increase of GRK2 protein. Deletion of Cul4a results in cardiac hypertrophy in male mice that can be partially rescued by the deletion of one Grk2 allele. These results reveal a non-canonical function of the Gβ protein as a ubiquitin ligase component and a mechanism of feedback regulation of GPCR signaling.
authors.affiliation: Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People's Republic of China; Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People's Republic of China; School of Life Sciences, Fudan University 200032, People's Republic of China; Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Zha
authors.affiliation: Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People's Republic of China; Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People's Republic of China; School of Life Sciences, Fudan University 200032, People's Republic of China.
authors.forename: Xiaoran
authors.initials: X
authors.lastname: Han
authors.affiliation: Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Smith
authors.affiliation: Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Pharmacology, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Giguère
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Illinois, College of Medicine, Chicago, IL 60607, USA.
authors.forename: Dragana
authors.initials: D
authors.lastname: Kopanja
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Illinois, College of Medicine, Chicago, IL 60607, USA.
authors.forename: Pradip
authors.initials: P
authors.lastname: Raychaudhuri
authors.affiliation: Department of Pharmacology, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: David P
authors.initials: DP
authors.lastname: Siderovski
authors.affiliation: Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People's Republic of China; Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People's Republic of China; Department of Pharmacology and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA. Electronic address: kuguan@ucsd.edu.
authors.forename: Kun-Liang
authors.initials: KL
authors.lastname: Guan
authors.affiliation: Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People's Republic of China; Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People's Republic of China. Electronic address: qlei@fudan.edu.cn.
authors.forename: Qun-Ying
authors.initials: QY
authors.lastname: Lei
authors.affiliation: Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People's Republic of China; Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People's Republic of China; Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA. Electronic address: yxiong@email.unc.edu.
authors.forename: Yue
authors.initials: Y
authors.lastname: Xiong
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D054769:G-Protein-Coupled Receptor Kinase 2 / Q000378:metabolism*; D044387:GTP-Binding Protein beta Subunits / Q000502:physiology*; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D018345:Mice, Knockout; D009687:Nuclear Proteins / Q000378:metabolism*; D055550:Protein Stability; D059748:Proteolysis; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: C091435:DDB1 protein, human; D004268:DNA-Binding Proteins; C429530:DTL protein, human; D044387:GTP-Binding Protein beta Subunits; D009687:Nuclear Proteins; D044767:Ubiquitin-Protein Ligases; C496567:GRK2 protein, human; D054769:G-Protein-Coupled Receptor Kinase 2