title: The B-domain lysine patch of pRB is required for binding to large T antigen and release of E2F by phosphorylation.
abstract: Cell cycle-dependent, site-specific phosphorylation of the retinoblastoma protein, pRB, is mediated by cyclin-dependent kinases (CDKs) and regulates the binding of pRB to many proteins. We previously showed that the interaction of pRB with E2F on DNA was regulated by the accumulation of phosphate groups on pRB. Here we show that positively charged lysine residues in the B domain of pRB are necessary for the release of pRB from E2F on DNA following phosphorylation by cyclin E-cdk2 kinase. These lysine residues are also important in the binding of the simian virus 40 large T antigen (TAg) to pRB, and mutation of these lysines to arginines alters the dependency of the pRB-TAg interaction on phosphorylation of pRB.
authors.affiliation: The Ontario Cancer Institute/Princess Margaret Hospital, University Health Network, and Department of Molecular and Medical Genetics, University of Toronto, Toronto, Ontario M5G 2M9, Canada.
authors.forename: Vivette D
authors.initials: VD
authors.lastname: Brown
authors.forename: Brenda L
authors.initials: BL
authors.lastname: Gallie
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000378:metabolism*; D001665:Binding Sites; D018797:Cell Cycle Proteins; D019927:Cyclin E / Q000378:metabolism; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D005786:Gene Expression Regulation; D056284:Histone Deacetylase 1; D006655:Histone Deacetylases / Q000378:metabolism; D006801:Humans; D008239:Lysine; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D016160:Retinoblastoma Protein / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D000952:Antigens, Polyomavirus Transforming; D018797:Cell Cycle Proteins; D019927:Cyclin E; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D016160:Retinoblastoma Protein; D014157:Transcription Factors; C110550:HDAC1 protein, human; D056284:Histone Deacetylase 1; D006655:Histone Deacetylases; D008239:Lysine