TATA-binding protein-free TAF-containing complex (TFTC) and p300 are both required for efficient transcriptional activation

J Biol Chem. 2002 Sep 6;277(36):32875-82. doi: 10.1074/jbc.M205860200. Epub 2002 Jul 9.

Abstract

Initiation of transcription of protein-encoding genes by RNA polymerase II was thought to require transcription factor TFIID, a complex comprising the TATA-binding protein (TBP) and TBP-associated factors (TAFs). In the presence of TBP-free TAF complex (TFTC), initiation of polymerase II transcription can occur in the absence of TFIID. TFTC contains several subunits that have been shown to play the role of transcriptional coactivators, including the GCN5 histone acetyltransferase (HAT), which acetylates histone H3 in a nucleosomal context. Here we analyze the coactivator function of TFTC. We show direct physical interactions between TFTC and the two distinct activation regions (H1 and H2) of the VP16 activation domain, whereas the HAT-containing coactivators, p300/CBP (CREB-binding protein), interact only with the H2 subdomain of VP16. Accordingly, cell transfection experiments demonstrate the requirement of both p300 and TFTC for maximal transcriptional activation by GAL-VP16. In agreement with this finding, we show that in vitro on a chromatinized template human TFTC mediates the transcriptional activity of the VP16 activation domain in concert with p300 and in an acetyl-CoA-dependent manner. Thus, our results suggest that these two HAT-containing co-activators, p300 and TFTC, have complementary rather than redundant roles during the transcriptional activation process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Blotting, Western
  • Cell Cycle Proteins
  • Chromatin / metabolism
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / physiology
  • Glutathione Transferase / metabolism
  • HeLa Cells
  • Histone Acetyltransferases
  • Humans
  • Immunoblotting
  • Macromolecular Substances
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / physiology*
  • Plasmids / metabolism
  • Protein Binding
  • Protein Structure, Tertiary
  • TATA-Binding Protein Associated Factors*
  • TATA-Box Binding Protein
  • Trans-Activators / chemistry
  • Trans-Activators / physiology*
  • Transcription Factor TFIID*
  • Transcription Factors / chemistry*
  • Transcription Factors / metabolism
  • Transcription Factors / physiology
  • Transcription, Genetic
  • Transcriptional Activation*
  • Transfection
  • p300-CBP Transcription Factors

Substances

  • Adaptor Proteins, Signal Transducing
  • Cell Cycle Proteins
  • Chromatin
  • DNA-Binding Proteins
  • Macromolecular Substances
  • Nuclear Proteins
  • TAF10 protein, human
  • TAF4 protein, human
  • TAF5 protein, human
  • TAF6 protein, human
  • TAF7 protein, human
  • TATA-Binding Protein Associated Factors
  • TATA-Box Binding Protein
  • Trans-Activators
  • Transcription Factor TFIID
  • Transcription Factors
  • transformation-transcription domain-associated protein
  • Histone Acetyltransferases
  • KAT2A protein, human
  • p300-CBP Transcription Factors
  • p300-CBP-associated factor
  • Glutathione Transferase