The modulator of the general stress response, MgsR, of Bacillus subtilis is subject to multiple and complex control mechanisms
Article first published online: 19 JUL 2012
© 2012 Society for Applied Microbiology and Blackwell Publishing Ltd
Thematic issue: Sulfur Metabolism
Volume 14, Issue 10, pages 2838–2850, October 2012
How to Cite
Reder, A., Pöther, D.-C., Gerth, U. and Hecker, M. (2012), The modulator of the general stress response, MgsR, of Bacillus subtilis is subject to multiple and complex control mechanisms. Environmental Microbiology, 14: 2838–2850. doi: 10.1111/j.1462-2920.2012.02829.x
- Issue published online: 3 OCT 2012
- Article first published online: 19 JUL 2012
- Accepted manuscript online: 3 JUL 2012 12:58AM EST
- Received 17 April, 2012; accepted 26 June, 2012.
The alternative sigma factor σB is the master regulator of the general stress regulon that comprises approximately 200 genes whose products confer a comprehensive stress resistance to Bacillus subtilis. The characterization of MgsR (modulator of the general stress response) revealed that the activation and induction of σB are a prerequisite but not sufficient for a full expression of all general stress genes. MgsR is a paralogue of the global regulator of the diamide stress response, Spx, and controls a subregulon of the general stress response. Here we demonstrate that MgsR activity is controlled at multiple levels. These mechanisms include a positive autoregulatory loop on mgsR transcription, a post-translational redox-sensitive activation step by an intramolecular disulfide bond formation in response to ethanol stress in vivo, as well as rapid proteolytic degradation of MgsR by the ClpXP and ClpCP proteases. Our results indicate an elaborate regulatory network integrating secondary oxidative stress signals into a σB-mediated regulatory cascade that is aimed at rapid and finely tuned target gene expression to coordinately fulfil the physiological needs of the cell in the face of multiple environmental changes.