JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Thackray, P. D.
Right arrow Articles by Moir, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Thackray, P. D.
Right arrow Articles by Moir, A.

 Previous Article  |  Next Article 

Journal of Bacteriology, June 2003, p. 3491-3498, Vol. 185, No. 12
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.12.3491-3498.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

SigM, an Extracytoplasmic Function Sigma Factor of Bacillus subtilis, Is Activated in Response to Cell Wall Antibiotics, Ethanol, Heat, Acid, and Superoxide Stress

Penny D. Thackray and Anne Moir*

Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom

Received 18 October 2002/ Accepted 26 March 2003

The extracytoplasmic function sigma M of Bacillus subtilis is required for normal cell growth under salt stress. It is expressed maximally during exponential growth and is further induced by the addition of 0.7 M NaCl. The promoter region of the sigM operon contains two promoters; one (PA) is sigma A dependent, and the other (PM) is sigma M dependent. These have been placed separately at the amy locus, directing expression of a lacZ reporter gene. Only the PM fusion responded to salt induction. This promoter, which was responsive to the level of active sigma M in the cell, was also induced by 5% ethanol, by vancomycin, bacitracin, or phosphomycin (inhibitors of cell wall biosynthesis; 2 µg per ml), and by heat shock of 50°C for 10 min. It was very strongly induced by acid (pH 4.3) and 80 µM paraquat, but after a 15- to 30-min delay. There was no induction by alkali (pH 9), 5 mM H2O2, the detergents 0.1% Triton X-100 and 0.1% Tween 20, or 50 µM monensin. In addition to their reduced tolerance to salt, null mutants of sigM were unable to grow at pH 4.3 and lysed after exposure to 5% ethanol. Genes regulated by SigM were also tested for their response to pH 4.3, 5% ethanol, and 2 µg of vancomycin per ml. Expression of the genes may have been activated by increased levels of sigma M, but at least some were also subject to additional controls, as they responded to one type of stress but not another. Expression of yrhJ, which encodes a cytochrome P450/NADPH reductase, was induced in response to acid and vancomycin. yraA expression was acid, ethanol, and vancomycin induced, whereas yjbD showed only ethanol induction. YraA protein was extremely important to acid survival—a mutation in yraA, like a sigM mutation, resulted in the failure of B. subtilis to grow at pH 4.3. Sigma M is therefore involved in maintaining membrane and cell wall integrity in response to several different stresses in exponential growth phase and is activated by such stresses.

* Corresponding author. Mailing address: Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, England S10 2TN. Phone: 44 0114 222 4418. Fax: 44 0114 272 8697. E-mail: A.Moir{at}sheffield.ac.uk.

Journal of Bacteriology, June 2003, p. 3491-3498, Vol. 185, No. 12
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.12.3491-3498.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2003 by the American Society for Microbiology. All rights reserved.