This Article Full Text (PDF) Other Versions of this Article: JB.00847-06v1 188/23/8160    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Balbontín, R. Articles by Casadesús, J. Search for Related Content PubMed PubMed Citation Articles by Balbontín, R. Articles by Casadesús, J.

 Previous Article  |  Next Article 

J. Bacteriol. doi:10.1128/JB.00847-06
Copyright (c) 2006, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

DNA adenine methylation regulates virulence gene expression in Salmonella enterica serovar Typhimurium

Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41080 Seville, Spain; Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom; Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CSIC), Campus de Cantoblanco, 28049 Madrid, Spain

^* To whom correspondence should be addressed. Email: casadesus{at}us.es.

	Abstract

Transcriptomic analyses during growth in Luria-Bertani medium were performed in strain SL1344 of Salmonella enterica serovar Typhimurium and in two isogenic derivatives lacking Dam methylase. More genes were repressed by Dam methylation than were activated by Dam methylation (139 vs 37). Key genes that were differentially regulated by Dam methylation were verified independently. The largest classes of Dam-repressed genes included genes belonging to the SOS regulon, as previously described in E. coli, and genes of the SOS-inducible Salmonella prophages ST64B, Gifsy-1 and Fels-2. Dam-dependent virulence-related genes were also identified. Invasion genes in pathogenicity island SPI-1 were activated by Dam methylation, while the fimbrial operon std was repressed by Dam methylation. Certain flagellar genes were repressed by Dam methylation, and Dam^- mutants of S. enterica showed reduced motility. Altered expression patterns in the absence of Dam methylation were also found for the chemotaxis genes cheR (repressed by Dam) and STM3216 (activated by Dam) and for the Braun lipoprotein gene, lppB (activated by Dam). The requirement of DNA adenine methylation for the regulation of specific virulence genes suggests that certain defects of Salmonella Dam^- mutants in the mouse model may be caused by altered patterns of gene expression.

This article has been cited by other articles:

• Kim, J.-S., Li, J., Barnes, I. H. A., Baltzegar, D. A., Pajaniappan, M., Cullen, T. W., Trent, M. S., Burns, C. M., Thompson, S. A. (2008). Role of the Campylobacter jejuni Cj1461 DNA Methyltransferase in Regulating Virulence Characteristics. J. Bacteriol. 190: 6524-6529 [Abstract] [Full Text]  
• Simon, R., Heithoff, D. M., Mahan, M. J., Samuel, C. E. (2007). Comparison of Tissue-Selective Proinflammatory Gene Induction in Mice Infected with Wild-Type, DNA Adenine Methylase-Deficient, and Flagellin-Deficient Salmonella enterica. Infect. Immun. 75: 5627-5639 [Abstract] [Full Text]  
• Prieto, A. I., Jakomin, M., Segura, I., Pucciarelli, M. G., Ramos-Morales, F., Garcia-del Portillo, F., Casadesus, J. (2007). The GATC-Binding Protein SeqA Is Required for Bile Resistance and Virulence in Salmonella enterica Serovar Typhimurium. J. Bacteriol. 189: 8496-8502 [Abstract] [Full Text]  
• Falker, S., Schilling, J., Schmidt, M. A., Heusipp, G. (2007). Overproduction of DNA Adenine Methyltransferase Alters Motility, Invasion, and the Lipopolysaccharide O-Antigen Composition of Yersinia enterocolitica. Infect. Immun. 75: 4990-4997 [Abstract] [Full Text]  
• Arraiano, C. M., Bamford, J., Brussow, H., Carpousis, A. J., Pelicic, V., Pfluger, K., Polard, P., Vogel, J. (2007). Recent Advances in the Expression, Evolution, and Dynamics of Prokaryotic Genomes. J. Bacteriol. 189: 6093-6100 [Full Text]  
• Badie, G., Heithoff, D. M., Sinsheimer, R. L., Mahan, M. J. (2007). Altered Levels of Salmonella DNA Adenine Methylase Are Associated with Defects in Gene Expression, Motility, Flagellar Synthesis, and Bile Resistance in the Pathogenic Strain 14028 but Not in the Laboratory Strain LT2. J. Bacteriol. 189: 1556-1564 [Abstract] [Full Text]