Redundancy of chromatin remodeling pathways for the induction of the yeast PHO5 promoter in vivo

J Biol Chem. 2007 Sep 21;282(38):27610-21. doi: 10.1074/jbc.M700623200. Epub 2007 Jul 13.

Abstract

Induction of the yeast PHO5 and PHO8 genes leads to a prominent chromatin transition at their promoter regions as a prerequisite for transcription activation. Although induction of PHO8 is strictly dependent on Snf2 and Gcn5, there is no chromatin remodeler identified so far that would be essential for the opening of PHO5 promoter chromatin. Nonetheless, the nonessential but significant involvement of cofactors can be identified if the chromatin opening kinetics are delayed in the respective mutants. Using this approach, we have tested individually all 15 viable Snf2 type ATPase deletion mutants for their effect on PHO5 promoter induction and opening. Only the absence of Snf2 and Ino80 showed a strong delay in chromatin remodeling kinetics. The snf2 ino80 double mutation had a synthetic kinetic effect but eventually still allowed strong PHO5 induction. The same was true for the snf2 gcn5 and ino80 gcn5 double mutants. This strongly suggests a complex network of redundant and mutually independent parallel pathways that lead to the remodeling of the PHO5 promoter. Further, chromatin remodeling kinetics at a transcriptionally inactive TATA box-mutated PHO5 promoter were affected neither under wild type conditions nor in the absence of Snf2 or Gcn5. This demonstrates the complete independence of promoter chromatin opening from downstream PHO5 transcription processes. Finally, the histone variant Htz1 has no prominent role for the kinetics of PHO5 promoter chromatin remodeling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Phosphatase
  • Adenosine Triphosphatases
  • Chromatin / chemistry
  • Chromatin / metabolism*
  • DNA-Binding Proteins / metabolism
  • Gene Deletion
  • Gene Expression Regulation, Fungal*
  • Histone Acetyltransferases / metabolism
  • Histones / metabolism
  • Kinetics
  • Models, Biological
  • Models, Genetic
  • Mutation
  • Promoter Regions, Genetic
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / physiology*
  • Transcription Factors / metabolism
  • Transcriptional Activation

Substances

  • Chromatin
  • DNA-Binding Proteins
  • Histones
  • Htz1 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • GCN5 protein, S cerevisiae
  • Histone Acetyltransferases
  • Acid Phosphatase
  • PHO5 protein, S cerevisiae
  • Adenosine Triphosphatases
  • SNF2 protein, S cerevisiae