The S. cerevisiae SAGA complex functions in vivo as a coactivator for transcriptional activation by Gal4

Genes Dev. 2001 Aug 1;15(15):1946-56. doi: 10.1101/gad.911501.

Abstract

Previous studies demonstrated that the SAGA (Spt-Ada-Gcn5-Acetyltransferase) complex facilitates the binding of TATA-binding protein (TBP) during transcriptional activation of the GAL1 gene of Saccharomyces cerevisiae. TBP binding was shown to require the SAGA components Spt3 and Spt20/Ada5, but not the SAGA component Gcn5. We have now examined whether SAGA is directly required as a coactivator in vivo by using chromatin immunoprecipitation analysis. Our results demonstrate that SAGA is physically recruited in vivo to the upstream activation sequence (UAS) regions of the galactose-inducible GAL genes. This recruitment is dependent on both induction by galactose and the Gal4 activation domain. Furthermore, we demonstrate that another well-characterized activator, Gal4-VP16, also recruits SAGA in vivo. Finally, we provide evidence that a specific interaction between Spt3 and TBP in vivo is important for Gal4 transcriptional activation at a step after SAGA recruitment. These results, taken together with previous studies, demonstrate a dependent pathway for the recruitment of TBP to GAL gene promoters consisting of the recruitment of SAGA by Gal4 and the subsequent recruitment of TBP by SAGA.

Publication types

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

MeSH terms

  • Acetyltransferases / metabolism*
  • Chromatin / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism*
  • Gene Expression Regulation, Fungal*
  • Genes, Fungal
  • Genotype
  • Histone Acetyltransferases
  • Models, Biological
  • Polymerase Chain Reaction
  • Promoter Regions, Genetic
  • Protein Kinases / metabolism*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • TATA-Box Binding Protein
  • Trans-Activators / metabolism*
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transcription, Genetic*

Substances

  • Chromatin
  • DNA-Binding Proteins
  • Fungal Proteins
  • GAL4 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • TATA-Box Binding Protein
  • Trans-Activators
  • Transcription Factors
  • Acetyltransferases
  • GCN5 protein, S cerevisiae
  • Histone Acetyltransferases
  • Protein Kinases