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  • The EMBO Journal (2007) 26, 2061 - 2070
  • doi:10.1038/sj.emboj.7601655

Published online: 22 March 2007

The tyrosine kinase McsB is a regulated adaptor protein for ClpCP

Janine Kirstein1, David A Dougan2, Ulf Gerth3, Michael Hecker3 and Kürs cedilad Turgay1

  1. Institut für Biologie—Mikrobiologie, FB Biologie, Chemie, Pharmazie, Freie Universität Berlin, Berlin, Germany
  2. Department of Biochemistry, La Trobe University, Melbourne, Australia
  3. Institut für Molekulare Mikrobiologie, Ernst Moritz Arndt Universität Greifswald, Greifswald, Germany

Correspondence to:

Kürs cedilad Turgay, Institut für Biologie—Mikrobiologie, FB Biologie, Chemie, Pharmazie, Freie Universität Berlin, Königin-Luise-Str. 12-16, Berlin 14195, Germany. Tel.: +49 30 83853111; Fax: 49 30 83853118. E-mail: kturgay@zedat.fu-berlin.de

Received 10 October 2006; Accepted 26 February 2007

Cells of the soil bacterium Bacillus subtilis have to adapt to fast environmental changes in their natural habitat. Here, we characterized a novel system in which cells respond to heat shock by regulatory proteolysis of a transcriptional repressor CtsR. In B. subtilis, CtsR controls the synthesis of itself, the tyrosine kinase McsB, its activator McsA and the Hsp100/Clp proteins ClpC, ClpE and their cognate peptidase ClpP. The AAA+ protein family members ClpC and ClpE can form an ATP-dependent protease complex with ClpP and are part of the B. subtilis protein quality control system. The regulatory response is mediated by a proteolytic switch, which is formed by these proteins under heat-shock conditions, where the tyrosine kinase McsB acts as a regulated adaptor protein, which in its phosphorylated form activates the Hsp100/Clp protein ClpC and targets the repressor CtsR for degradation by the general protease ClpCP.

  • Keywords:

    • AAA+ proteins,
    • adaptor proteins,
    • heat shock regulation,
    • proteolysis,
    • tyrosine kinase