The eukaryotic two-component histidine kinase Sln1p regulates OCH1 via the transcription factor, Skn7p

Mol Biol Cell. 2002 Feb;13(2):412-24. doi: 10.1091/mbc.01-09-0434.

Abstract

The yeast "two-component" osmotic stress phosphorelay consists of the histidine kinase, Sln1p, the phosphorelay intermediate, Ypd1p and two response regulators, Ssk1p and Skn7p, whose activities are regulated by phosphorylation of a conserved aspartyl residue in the receiver domain. Dephospho-Ssk1p leads to activation of the hyper-osmotic response (HOG) pathway, whereas phospho-Skn7p presumably leads to activation of hypo-osmotic response genes. The multifunctional Skn7 protein is important in oxidative as well as osmotic stress; however, the Skn7p receiver domain aspartate that is the phosphoacceptor in the SLN1 pathway is dispensable for oxidative stress. Like many well-characterized bacterial response regulators, Skn7p is a transcription factor. In this report we investigate the role of Skn7p in osmotic response gene activation. Our studies reveal that the Skn7p HSF-like DNA binding domain interacts with a cis-acting element identified upstream of OCH1 that is distinct from the previously defined HSE-like Skn7p binding site. Our data support a model in which Skn7p receiver domain phosphorylation affects transcriptional activation rather than DNA binding to this class of DNA binding site.

Publication types

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

MeSH terms

  • Aspartic Acid / metabolism
  • Binding Sites
  • Cell Wall / metabolism
  • DNA-Binding Proteins / metabolism*
  • Fungal Proteins / metabolism*
  • Fungal Proteins / physiology*
  • Gene Expression Regulation, Fungal
  • Intracellular Signaling Peptides and Proteins
  • Mannosyltransferases*
  • Membrane Glycoproteins / metabolism*
  • Promoter Regions, Genetic
  • Protein Kinases*
  • Response Elements
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / physiology
  • Saccharomyces cerevisiae Proteins*
  • Sequence Analysis, DNA
  • Signal Transduction / physiology
  • Terminal Repeat Sequences
  • Transcription Factors / metabolism*
  • Transcriptional Activation

Substances

  • DNA-Binding Proteins
  • Fungal Proteins
  • Intracellular Signaling Peptides and Proteins
  • Membrane Glycoproteins
  • OCH1 protein, S cerevisiae
  • SKN7 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Aspartic Acid
  • Mannosyltransferases
  • Protein Kinases
  • SLN1 protein, S cerevisiae