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A tyrosine kinase and its activator control the activity of the CtsR heat shock repressor in B. subtilis
Author(s) -
Kirstein Janine,
Zühlke Daniela,
Gerth Ulf,
Turgay Kürşad,
Hecker Michael
Publication year - 2005
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7600780
Subject(s) - biology , repressor , activator (genetics) , bacillus subtilis , tyrosine kinase , tyrosine , biochemistry , heat shock , kinase , heat shock protein , microbiology and biotechnology , genetics , signal transduction , transcription factor , gene , bacteria
The soil bacterium Bacillus subtilis possesses a fine‐tuned and complex heat stress response system. The repressor CtsR, whose activity is regulated by its modulators McsA and McsB, controls the expression of the cellular protein quality control genes clpC , clpE and clpP . Here, we show that the interaction of McsA and McsB with CtsR results in the formation of a ternary complex that not only prevents the binding of CtsR to its target DNA, but also results in a subsequent phosphorylation of McsB, McsA and CtsR. We further demonstrate that McsB is a tyrosine kinase that needs McsA to become activated. ClpC inhibits the kinase activity of McsB, indicating a direct role in initiating CtsR‐controlled heat shock response. Interestingly, the kinase domain of McsB is homologous to guanidino phosphotransferase domains originating from eukaryotic arginine and creatine kinases. Mutational analysis of key residues of the guanidino kinase domain demonstrated that McsB utilizes this domain to catalyze the tyrosine phosphorylation. McsB represents therefore a new kind of tyrosine kinase, driven by a guanidino phosphotransferase domain.