This Article Full Text Full Text (PDF) 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 Shetron-Rama, L. M. Articles by Freitag, N. E. Search for Related Content PubMed PubMed Citation Articles by Shetron-Rama, L. M. Articles by Freitag, N. E.

 Previous Article  |  Next Article 

Infection and Immunity, March 2002, p. 1087-1096, Vol. 70, No. 3
0019-9567/02/$04.00+0     DOI: 10.1128/IAI.70.3.1087-1096.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Intracellular Induction of Listeria monocytogenes actA Expression

Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, Michigan 48201,¹ Department of Microbiology and Immunology, Cornell University, Ithaca, New York 14853,² Immunology Research, Veterans Affairs Medical Center,³ Earle A Chiles Research Institute, Portland, Oregon 97201,⁴ Seattle Biomedical Research Institute,⁵ Department of Pathobiology, University of Washington, Seattle, Washington 98195⁶

Received 8 August 2001/ Returned for modification 16 October 2001/ Accepted 25 November 2001

Following entry into the host cytosol, the bacterial pathogen Listeria monocytogenes dramatically increases the expression of several key virulence factors. The expression of actA, whose protein product is required for L. monocytogenes actin-based intracellular motility, is increased by more than 200-fold in cytosolic bacteria in comparison to broth-grown cultures. Two distinct promoter elements have been reported to regulate actA expression. One promoter is located immediately upstream of actA coding sequences, while the second promoter is contributed by the upstream mpl gene via the generation of an mpl-actA-plcB transcript. A series of L. monocytogenes mutants were constructed to define the contributions of individual promoter elements to actA expression. The intracellular induction of actA expression was found to be dependent upon the actA proximal promoter; the mpl promoter appeared to contribute to the extracellular induction of actA but did not affect intracellular levels of expression. The actA promoter is dependent upon a regulatory factor known as PrfA for transcriptional activation; however, no increase in actA expression was detected following the introduction of a high-affinity PrfA binding site within the actA promoter. The presence of a mutationally activated form of PrfA, known as PrfA*, increased overall actA expression in broth-grown cultures of both wild-type and actA promoter mutant strains, but the levels of induction observed were still approximately 50-fold lower than those observed for intracellularly grown L. monocytogenes. Collectively, these results indicate that the dramatic induction of actA expression that occurs in the host cell cytosol is mediated through a single promoter element. Furthermore, intracellular induction of actA appears to require additional steps or factors beyond those necessary for the activation and binding of PrfA to the actA promoter.

This article has been cited by other articles:

• Footer, M. J., Lyo, J. K., Theriot, J. A. (2008). Close Packing of Listeria monocytogenes ActA, a Natively Unfolded Protein, Enhances F-actin Assembly without Dimerization. J. Biol. Chem. 283: 23852-23862 [Abstract] [Full Text]  
• Lauer, P., Hanson, B., Lemmens, E. E., Liu, W., Luckett, W. S., Leong, M. L., Allen, H. E., Skoble, J., Bahjat, K. S., Freitag, N. E., Brockstedt, D. G., Dubensky, T. W. Jr. (2008). Constitutive Activation of the PrfA Regulon Enhances the Potency of Vaccines Based on Live-Attenuated and Killed but Metabolically Active Listeria monocytogenes Strains. Infect. Immun. 76: 3742-3753 [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]  
• Port, G. C., Freitag, N. E. (2007). Identification of Novel Listeria monocytogenes Secreted Virulence Factors following Mutational Activation of the Central Virulence Regulator, PrfA. Infect. Immun. 75: 5886-5897 [Abstract] [Full Text]  
• Gray, M. J., Freitag, N. E., Boor, K. J. (2006). How the Bacterial Pathogen Listeria monocytogenes Mediates the Switch from Environmental Dr. Jekyll to Pathogenic Mr. Hyde.. Infect. Immun. 74: 2505-2512 [Full Text]  
• Zhao, X., Li, Z., Gu, B., Frankel, F. R. (2005). Pathogenicity and Immunogenicity of a Vaccine Strain of Listeria monocytogenes That Relies on a Suicide Plasmid To Supply an Essential Gene Product. Infect. Immun. 73: 5789-5798 [Abstract] [Full Text]  
• Roberts, A., Chan, Y., Wiedmann, M. (2005). Definition of Genetically Distinct Attenuation Mechanisms in Naturally Virulence-Attenuated Listeria monocytogenes by Comparative Cell Culture and Molecular Characterization. Appl. Environ. Microbiol. 71: 3900-3910 [Abstract] [Full Text]  
• Mueller, K. J., Freitag, N. E. (2005). Pleiotropic Enhancement of Bacterial Pathogenesis Resulting from the Constitutive Activation of the Listeria monocytogenes Regulatory Factor PrfA. Infect. Immun. 73: 1917-1926 [Abstract] [Full Text]  
• Wong, K. K. Y., Freitag, N. E. (2004). A Novel Mutation within the Central Listeria monocytogenes Regulator PrfA That Results in Constitutive Expression of Virulence Gene Products. J. Bacteriol. 186: 6265-6276 [Abstract] [Full Text]  
• Rea, R. B., Gahan, C. G. M., Hill, C. (2004). Disruption of Putative Regulatory Loci in Listeria monocytogenes Demonstrates a Significant Role for Fur and PerR in Virulence. Infect. Immun. 72: 717-727 [Abstract] [Full Text]  
• Milenbachs Lukowiak, A., Mueller, K. J., Freitag, N. E., Youngman, P. (2004). Deregulation of Listeria monocytogenes virulence gene expression by two distinct and semi-independent pathways. Microbiology 150: 321-333 [Abstract] [Full Text]  
• Grundling, A., Gonzalez, M. D., Higgins, D. E. (2003). Requirement of the Listeria monocytogenes Broad-Range Phospholipase PC-PLC during Infection of Human Epithelial Cells. J. Bacteriol. 185: 6295-6307 [Abstract] [Full Text]  
• Greene, S. L., Freitag, N. E. (2003). Negative regulation of PrfA, the key activator of Listeria monocytogenes virulence gene expression, is dispensable for bacterial pathogenesis. Microbiology 149: 111-120 [Abstract] [Full Text]  
• Dancz, C. E., Haraga, A., Portnoy, D. A., Higgins, D. E. (2002). Inducible Control of Virulence Gene Expression in Listeria monocytogenes: Temporal Requirement of Listeriolysin O during Intracellular Infection. J. Bacteriol. 184: 5935-5945 [Abstract] [Full Text]  
• Lauer, P., Chow, M. Y. N., Loessner, M. J., Portnoy, D. A., Calendar, R. (2002). Construction, Characterization, and Use of Two Listeria monocytogenes Site-Specific Phage Integration Vectors. J. Bacteriol. 184: 4177-4186 [Abstract] [Full Text]