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Article

  • The EMBO Journal (2005) 24, 4115 - 4123
  • doi:10.1038/sj.emboj.7600871

Published online: 10 November 2005

A dual role for PP1 in shaping the Msn2-dependent transcriptional response to glucose starvation

Veerle De Wever1, Wolfgang Reiter1, Annalisa Ballarini1, Gustav Ammerer1 and Cécile Brocard1

  1. Max F Perutz Laboratories, University Departments at the Vienna Biocenter, Department of Biochemistry, University of Vienna and Ludwig Boltzmann-Forschungsstelle für Biochemie, Vienna, Austria

Correspondence to:

Cécile Brocard, Max F Perutz Laboratories, University Departments at the Vienna Biocenter, Department of Biochemistry, Vienna Biocenter, University of Vienna and Ludwig Boltzmann-Forschungsstelle für Biochemie, Dr Bohrgasse 9, 1030 Vienna, Austria. Tel.: +43 1 42 77 52 817; Fax: +43 1 42 77 9 528; E-mail: cecile.brocard@univie.ac.at

Received 13 July 2005; Accepted 19 October 2005

In yeast, glucose depletion elicits a quick response in the transcription of stress-related genes. The main transcriptional activator that orchestrates this response is Msn2, whose nuclear localization and DNA binding are negatively controlled by the cAMP-dependent protein kinase (PKA). Msn2 activation by sudden glucose depletion correlates with a fast but transient decrease in phosphorylation of several sites in its nuclear localization signal (NLS). Here we show that protein phosphatase 1 (PP1) is the direct antagonist of PKA-dependent phosphorylation at the Msn2 nuclear import domain and therefore a potential mediator of glucose starvation signals that target this transcription factor. Apart from PKA, the protein kinase Snf1 can also directly modify one of the Msn2 phosphorylation sites (S582) and thereby repress Msn2 function. Consequently, in snf1 mutants, rephosphorylation of the NLS happens to be much slower during prolonged starvation. Thus, a second, Reg1-dependent form of PP1 indirectly influences Msn2 functionality by modulating Snf1 kinase activation and repression. Different activities of PP1 are therefore involved in shaping induction and adaptation of the transcriptional stress response during acute glucose starvation.

  • Keywords:

    • glucose sensing,
    • Msn2,
    • PP1,
    • Snf1,
    • transcriptional regulation