The Ccr4-Not complex independently controls both Msn2-dependent transcriptional activation--via a newly identified Glc7/Bud14 type I protein phosphatase module--and TFIID promoter distribution

Mol Cell Biol. 2005 Jan;25(1):488-98. doi: 10.1128/MCB.25.1.488-498.2005.

Abstract

The Ccr4-Not complex is a conserved global regulator of gene expression, which serves as a regulatory platform that senses and/or transmits nutrient and stress signals to various downstream effectors. Presumed effectors of this complex in yeast are TFIID, a general transcription factor that associates with the core promoter, and Msn2, a key transcription factor that regulates expression of stress-responsive element (STRE)-controlled genes. Here we show that the constitutively high level of STRE-driven expression in ccr4-not mutants results from two independent effects. Accordingly, loss of Ccr4-Not function causes a dramatic Msn2-independent redistribution of TFIID on promoters with a particular bias for STRE-controlled over ribosomal protein gene promoters. In parallel, loss of Ccr4-Not complex function results in an alteration of the posttranslational modification status of Msn2, which depends on the type 1 protein phosphatase Glc7 and its newly identified subunit Bud14. Tests of epistasis as well as transcriptional analyses of Bud14-dependent transcription support a model in which the Ccr4-Not complex prevents activation of Msn2 via inhibition of the Bud14/Glc7 module in exponentially growing cells. Thus, increased activity of STRE genes in ccr4-not mutants may result from both altered general distribution of TFIID and unscheduled activation of Msn2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle Proteins / physiology*
  • Cross-Linking Reagents / pharmacology
  • DNA / metabolism
  • DNA-Binding Proteins / physiology*
  • Gene Expression Regulation
  • Genotype
  • Glucose / metabolism
  • Immunoblotting
  • Immunoprecipitation
  • Models, Biological
  • Mutation
  • Nucleic Acid Hybridization
  • Phosphoprotein Phosphatases / metabolism
  • Plasmids / metabolism
  • Promoter Regions, Genetic
  • Protein Binding
  • Protein Phosphatase 1
  • Protein Processing, Post-Translational
  • RNA, Messenger / metabolism
  • Ribonucleases / physiology*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / physiology*
  • Time Factors
  • Transcription Factor TFIID / chemistry
  • Transcription Factors / physiology*
  • Transcription, Genetic
  • Transcriptional Activation*
  • Two-Hybrid System Techniques

Substances

  • Bud14 protein, S cerevisiae
  • CDC39 protein, S cerevisiae
  • Cell Cycle Proteins
  • Cross-Linking Reagents
  • DNA-Binding Proteins
  • MSN2 protein, S cerevisiae
  • RNA, Messenger
  • Saccharomyces cerevisiae Proteins
  • Transcription Factor TFIID
  • Transcription Factors
  • DNA
  • CCR4 protein, S cerevisiae
  • Ribonucleases
  • GLC7 protein, S cerevisiae
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 1
  • Glucose