E2F is required to prevent inappropriate S-phase entry of mammalian cells

Mol Cell Biol. 2000 Jan;20(1):363-71. doi: 10.1128/MCB.20.1.363-371.2000.


E2F is a family of transcription factors that regulates the cell cycle. It is widely accepted that E2F-mediated transactivation of a set of genes is the critical activity that governs cellular progression through G(1) into S phase. In contrast to this hypothesis, we demonstrate that E2F actually suppresses the onset of S phase in two cell types when the cells are arrested by gamma irradiation. Our findings indicate that in these cells, the critical event triggering progression from G(0)/G(1) arrest into S phase is the release of E2F-mediated transrepression of cell cycle genes, not transactivation by E2F. Furthermore, our data suggest that E2F-mediated transactivation is not necessary for the G(1)/S-phase transition in these cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Carrier Proteins*
  • Cell Cycle / genetics*
  • Cell Cycle Proteins*
  • Cells, Cultured
  • DNA-Binding Proteins*
  • E2F Transcription Factors
  • Gene Expression Regulation*
  • Retinoblastoma-Binding Protein 1
  • S Phase / genetics
  • Transcription Factors / genetics*


  • Carrier Proteins
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • E2F Transcription Factors
  • Retinoblastoma-Binding Protein 1
  • Transcription Factors