title: The accumulation of an E2F-p130 transcriptional repressor distinguishes a G0 cell state from a G1 cell state.
abstract: Previous studies have demonstrated cell cycle-dependent specificities in the interactions of E2F proteins with Rb family members. We now show that the formation of an E2F-p130 complex is unique to cells in a quiescent, G0 state. The E2F-p130 complex does not reform when cells reenter a proliferative state and cycle through G1. The presence of an E2F-p130 complex in quiescent cells coincides with the E2F-mediated repression of transcription of the E2F1 gene, and we show that the E2F sites in the E2F1 promoter are important as cells enter quiescence but play no apparent role in cycling cells. In addition, the decay of the E2F-p130 complex as cells reenter the cell cycle requires the action of G1 cyclin-dependent kinase activity. We conclude that the accumulation of the E2F-p130 complex in quiescent cells provides a negative control of certain key target genes and defines a functional distinction between these G0 cells and cells that exist transiently in G1.
authors.affiliation: Department of Genetics, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Smith
authors.forename: G
authors.initials: G
authors.lastname: Leone
authors.forename: J
authors.initials: J
authors.lastname: DeGregori
authors.forename: L
authors.initials: L
authors.lastname: Jakoi
authors.forename: J R
authors.initials: JR
authors.lastname: Nevins
mesh_terms: D016475:3T3 Cells; D000818:Animals; D015415:Biomarkers; D002352:Carrier Proteins; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D016193:G1 Phase / Q000235:genetics*; D005786:Gene Expression Regulation; D051379:Mice; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D011506:Proteins; D016192:Resting Phase, Cell Cycle / Q000235:genetics*; D056465:Retinoblastoma-Binding Protein 1; D050717:Retinoblastoma-Like Protein p130; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C533431:Arid4a protein, mouse; D015415:Biomarkers; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; C493754:E2f1 protein, mouse; D010750:Phosphoproteins; D011506:Proteins; C493838:Rbl2 protein, mouse; D056465:Retinoblastoma-Binding Protein 1; D050717:Retinoblastoma-Like Protein p130; D050680:Transcription Factor DP1; D014157:Transcription Factors