E2F mediates cell cycle-dependent transcriptional repression in vivo by recruitment of an HDAC1/mSin3B corepressor complex

  1. Joseph B. Rayman1,
  2. Yasuhiko Takahashi1,4,
  3. Vahan B. Indjeian1,
  4. Jan-Hermen Dannenberg2,
  5. Steven Catchpole3,
  6. Roger J. Watson3,
  7. Hein te Riele2, and
  8. Brian David Dynlacht1,5
  1. 1Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA; 2The Netherlands Cancer Institute, Division of Molecular Biology, 1066 CX Amsterdam, The Netherlands; 3Ludwig Institute for Cancer Research, Faculty of Medicine, Imperial College, Norfolk Place, London W2 1PG, UK

Abstract

Despite biochemical and genetic data suggesting that E2F and pRB (pocket protein) families regulate transcription via chromatin-modifying factors, the precise mechanisms underlying gene regulation by these protein families have not yet been defined in a physiological setting. In this study, we have investigated promoter occupancy in wild-type and pocket protein-deficient primary cells. We show that corepressor complexes consisting of histone deacetylase (HDAC1) and mSin3B were specifically recruited to endogenous E2F-regulated promoters in quiescent cells. These complexes dissociated from promoters once cells reached late G1, coincident with gene activation. Interestingly, recruitment of HDAC1 complexes to promoters depended absolutely on p107 and p130, and required an intact E2F-binding site. In contrast, mSin3B recruitment to certain promoters did not require p107 or p130, suggesting that recruitment of this corepressor can occur via E2F-dependent and -independent mechanisms. Remarkably, loss of pRB had no effect on HDAC1 or mSin3B recruitment. p107/p130 deficiency triggered a dramatic loss of E2F4 nuclear localization as well as transcriptional derepression, which is suggested by nucleosome mapping studies to be the result of localized hyperacetylation of nucleosomes proximal to E2F-binding sites. Taken together, these findings show that p130 escorts E2F4 into the nucleus and, together with corepressor complexes that contain mSin3B and/or HDAC1, directly represses transcription from target genes as cells withdraw from the cell cycle.

Keywords

Footnotes

  • 4 Present address: Environmental Health Science Laboratory, Sumitomo Chemical Co., Osaka 554-8558, Japan.

  • 5 Corresponding author.

  • E-MAIL dynlacht{at}envoy.mcb.harvard.edu; FAX (617) 496-1391.

  • Article and publication are at http://www.genesdev.org/cgi/doi/10.1101/gad.969202.

    • Received December 12, 2001.
    • Accepted February 27, 2002.
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