Gal80 confers specificity on HAT complex interactions with activators

J Biol Chem. 2002 Jul 5;277(27):24648-52. doi: 10.1074/jbc.M201965200. Epub 2002 May 1.


Several yeast transcription activators have been shown to interact with and recruit histone acetyltransferase complexes to promoters in chromatin. The promiscuity of activator/HAT interactions suggests that additional factors temporally regulate these interactions in response to signaling pathways. In this study, we demonstrate that the negative regulator, Gal80, blocks interactions between the SAGA and NuA4 HAT complexes and the Gal4 activator. By contrast, Gal80 did not inhibit SAGA and NuA4 interaction with another activator Gcn4. The function of Gal80 prevented Gal4 targeting of SAGA and displaced SAGA targeted by Gal4 to a promoter within a nucleosome array. In the same set of experiments, targeting of SAGA by Gcn4 was unaffected by Gal80. These studies demonstrate that the specificity of HAT/activator interactions can be dictated by cofactors that modulate activation domain function in response to cellular signals.

Publication types

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

MeSH terms

  • Acetyltransferases / metabolism*
  • Enzyme Activation
  • Fungal Proteins / metabolism*
  • Glutathione Transferase / metabolism
  • Histone Acetyltransferases
  • Kinetics
  • Recombinant Fusion Proteins / antagonists & inhibitors
  • Recombinant Fusion Proteins / metabolism
  • Repressor Proteins / metabolism
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins*


  • Fungal Proteins
  • GAL80 protein, S cerevisiae
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • SAGA protein, Emericella nidulans
  • Saccharomyces cerevisiae Proteins
  • Acetyltransferases
  • Histone Acetyltransferases
  • Glutathione Transferase