Acetylation of TAF(I)68, a subunit of TIF-IB/SL1, activates RNA polymerase I transcription

EMBO J. 2001 Mar 15;20(6):1353-62. doi: 10.1093/emboj/20.6.1353.

Abstract

Mammalian rRNA genes are preceded by a terminator element that is recognized by the transcription termination factor TTF-I. In exploring the functional significance of the promoter-proximal terminator, we found that TTF-I associates with the p300/CBP-associated factor PCAF, suggesting that TTF-I may target histone acetyltransferase to the rDNA promoter. We demonstrate that PCAF acetylates TAF(I)68, the second largest subunit of the TATA box-binding protein (TBP)-containing factor TIF-IB/SL1, and acetylation enhances binding of TAF(I)68 to the rDNA promoter. Moreover, PCAF stimulates RNA polymerase I (Pol I) transcription in a reconstituted in vitro system. Consistent with acetylation of TIF-IB/SL1 being required for rDNA transcription, the NAD(+)-dependent histone deacetylase mSir2a deacetylates TAF(I)68 and represses Pol I transcription. The results demonstrate that acetylation of the basal Pol I transcription machinery has functional consequences and suggest that reversible acetylation of TIF-IB/SL1 may be an effective means to regulate rDNA transcription in response to external signals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Acetyltransferases / antagonists & inhibitors
  • Acetyltransferases / metabolism*
  • Animals
  • DNA, Ribosomal
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation, Enzymologic
  • Gene Silencing
  • Histone Acetyltransferases
  • Histone Deacetylases / metabolism
  • Hydroxamic Acids / pharmacology
  • Mice
  • Pol1 Transcription Initiation Complex Proteins*
  • Protein Binding
  • Protein Subunits
  • RNA Polymerase I / biosynthesis*
  • RNA Polymerase I / genetics
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Silent Information Regulator Proteins, Saccharomyces cerevisiae*
  • Sirtuin 2
  • Sirtuins
  • TATA-Box Binding Protein
  • Terminator Regions, Genetic
  • Trans-Activators / metabolism
  • Transcription Factors / metabolism*
  • Transcription, Genetic

Substances

  • DNA, Ribosomal
  • DNA-Binding Proteins
  • Hydroxamic Acids
  • Pol1 Transcription Initiation Complex Proteins
  • Protein Subunits
  • Recombinant Proteins
  • Saccharomyces cerevisiae Proteins
  • Silent Information Regulator Proteins, Saccharomyces cerevisiae
  • TAF(i)68 protein, mouse
  • TATA-Box Binding Protein
  • Trans-Activators
  • Transcription Factors
  • transcription initiation factor TIF-IB
  • trichostatin A
  • Acetyltransferases
  • Histone Acetyltransferases
  • RNA Polymerase I
  • SIR2 protein, S cerevisiae
  • Sirtuin 2
  • Sirtuins
  • Histone Deacetylases