This Article Full Text (PDF) Other Versions of this Article: AEM.02664-06v1 73/9/2919    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 Mc Gann, P. Articles by Boor, K. J. Search for Related Content PubMed PubMed Citation Articles by Mc Gann, P. Articles by Boor, K. J. Agricola Articles by Mc Gann, P. Articles by Boor, K. J.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol. doi:10.1128/AEM.02664-06
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

The alternative sigma factor ^B and the virulence gene regulator PrfA both regulate transcription of Listeria monocytogenes internalins

Department of Food Science, Cornell University, Ithaca, New York 14853, USA

^* To whom correspondence should be addressed. Email: kjb4{at}cornell.edu.

	Abstract

Some Listeria monocytogenes internalins are recognized as contributing to invasion of mammalian tissue culture cells. While PrfA is well-established as a positive regulator of L. monocytogenes virulence gene expression, the stress responsive ^B has been recognized only recently as contributing to expression of virulence genes, including some that encode internalins. To measure the relative contributions of PrfA and ^B to internalin gene transcription, we used RT-PCR to quantify transcript levels for eight internalin genes (inlA, inlB, inlC, inlC2, inlD, inlE, inlF and inlG) in L. monocytogenes 10403S and in isogenic prfA, sigB and sigBprfA strains. Strains were grown under defined conditions to produce (i) active PrfA; (ii) active ^B and active PrfA; (iii) inactive PrfA; and (iv) active ^B and inactive PrfA. Under the conditions tested, ^B and PrfA contributed differentially to expression of the various internalins such that (i) both ^B and PrfA contributed to inlA and inlB transcription, (ii) only PrfA contributed to inlC transcription, (iii) only ^B contributed to inlC2 and inlD transcription, and (iv) neither ^B nor PrfA contributed to inlF and inlG transcription. Transcript levels were undetectable for inlE. The important role for ^B in regulating expression of L. monocytogenes internalins suggests that exposure of this organism to environmental stress conditions, such as those encountered in the gastrointestinal tract, may activate internalin transcription. Interplay between ^B and PrfA also appears to be critical for regulating transcription of some virulence genes, including inlA, inlB, and prfA.

This article has been cited by other articles:

• Abram, F., Starr, E., Karatzas, K. A. G., Matlawska-Wasowska, K., Boyd, A., Wiedmann, M., Boor, K. J., Connally, D., O'Byrne, C. P. (2008). Identification of Components of the Sigma B Regulon in Listeria monocytogenes That Contribute to Acid and Salt Tolerance. Appl. Environ. Microbiol. 74: 6848-6858 [Abstract] [Full Text]  
• Nightingale, K. K., Ivy, R. A., Ho, A. J., Fortes, E. D., Njaa, B. L., Peters, R. M., Wiedmann, M. (2008). inlA Premature Stop Codons Are Common among Listeria monocytogenes Isolates from Foods and Yield Virulence-Attenuated Strains That Confer Protection against Fully Virulent Strains. Appl. Environ. Microbiol. 74: 6570-6583 [Abstract] [Full Text]  
• Sabet, C., Toledo-Arana, A., Personnic, N., Lecuit, M., Dubrac, S., Poupel, O., Gouin, E., Nahori, M.-A., Cossart, P., Bierne, H. (2008). The Listeria monocytogenes Virulence Factor InlJ Is Specifically Expressed In Vivo and Behaves as an Adhesin. Infect. Immun. 76: 1368-1378 [Abstract] [Full Text]  
• Abram, F., Su, W.-L., Wiedmann, M., Boor, K. J., Coote, P., Botting, C., Karatzas, K. A. G., O'Byrne, C. P. (2008). Proteomic Analyses of a Listeria monocytogenes Mutant Lacking {sigma}B Identify New Components of the {sigma}B Regulon and Highlight a Role for {sigma}B in the Utilization of Glycerol. Appl. Environ. Microbiol. 74: 594-604 [Abstract] [Full Text]  
• Raengpradub, S., Wiedmann, M., Boor, K. J. (2008). Comparative Analysis of the {sigma}B-Dependent Stress Responses in Listeria monocytogenes and Listeria innocua Strains Exposed to Selected Stress Conditions. Appl. Environ. Microbiol. 74: 158-171 [Abstract] [Full Text]  
• Hu, Y., Raengpradub, S., Schwab, U., Loss, C., Orsi, R. H., Wiedmann, M., Boor, K. J. (2007). Phenotypic and Transcriptomic Analyses Demonstrate Interactions between the Transcriptional Regulators CtsR and Sigma B in Listeria monocytogenes. Appl. Environ. Microbiol. 73: 7967-7980 [Abstract] [Full Text]  
• Hu, Y., Oliver, H. F., Raengpradub, S., Palmer, M. E., Orsi, R. H., Wiedmann, M., Boor, K. J. (2007). Transcriptomic and Phenotypic Analyses Suggest a Network between the Transcriptional Regulators HrcA and {sigma}B in Listeria monocytogenes. Appl. Environ. Microbiol. 73: 7981-7991 [Abstract] [Full Text]