Hyperphosphorylation of Msn2p and Msn4p in response to heat shock and the diauxic shift is inhibited by cAMP in Saccharomyces cerevisiae

Microbiology. 2000 Sep;146 ( Pt 9):2113-2120. doi: 10.1099/00221287-146-9-2113.

Abstract

In response to various stresses, as well as during the diauxic transition, the Msn2p and Msn4p transcription factors of Saccharomyces cerevisiae are activated and induce a large set of genes. This activation is inhibited by the Ras/cAMP/PKA (cAMP-dependent protein kinase) pathway. Here we show by immunoblotting experiments that Msn2p and Msn4p are phosphorylated in vivo during growth on glucose, and become hyperphosphorylated at the diauxic transition and upon heat shock. This hyperphosphorylation is correlated with activation of Msn2/4p-dependent transcription. An increased level of cAMP prevents and reverses these hyperphosphorylations, indicating that kinases other than PKA are involved. These results suggest that PKA and stress-activated kinases control Msn2/4p activity by antagonistic phosphorylation. It was also noted that Msn4p is transiently increased at the diauxic transition. Msn2p and Msn4p present different hyperphosphorylation patterns in response to different stresses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / metabolism*
  • Cyclic AMP / metabolism*
  • Cyclic AMP / pharmacology
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation, Fungal
  • Heat-Shock Response*
  • Immunoblotting
  • Phosphorylation / drug effects
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / growth & development
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae Proteins*
  • Transcription Factors / metabolism*

Substances

  • DNA-Binding Proteins
  • MSN2 protein, S cerevisiae
  • MSN4 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • Alkaline Phosphatase