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 Mavris, M. Articles by Parsot, C. Search for Related Content PubMed PubMed Citation Articles by Mavris, M. Articles by Parsot, C.

Next Article 

Journal of Bacteriology, December 2002, p. 6751-6759, Vol. 184, No. 24
0021-9193/02/$04.00+0     DOI: 10.1128/JB.184.24.6751-6759.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Identification of the cis-Acting Site Involved in Activation of Promoters Regulated by Activity of the Type III Secretion Apparatus in Shigella flexneri

Unité de Pathogénie Microbienne Moléculaire, INSERM U389, Institut Pasteur, 75724 Paris Cedex 15, France

Received 21 June 2002/ Accepted 16 September 2002

Bacteria of Shigella spp. use a virulence plasmid-encoded type III secretion (TTS) system to invade the colonic epithelium in humans. The activity of the TTS apparatus is tightly regulated in the wild-type strain and is induced upon contact of bacteria with epithelial cells, whereas it is deregulated, i.e., constitutively active, in some mutants. Under conditions of deregulated secretion, approximately 20 proteins are secreted, including VirA, OspB to OspG, and at least three members of the IpaH family, all of which are encoded by the virulence plasmid. Conditions inducing or deregulating the activity of secretion also induce the transcription of virA and four ipaH genes. The transcription of virA and ipaH9.8 requires both MxiE, a transcriptional activator of the AraC family, and IpgC, the chaperone of IpaB and IpaC, acting as a coactivator. Using reporter plasmids containing lacZ transcriptional fusions, we showed that the ipaH7.8. ipa4.5. ospC1, and ospF promoters are activated under conditions of deregulated secretion and that both MxiE and IpgC are necessary and sufficient for their activation in both Shigella flexneri and Escherichia coli. Promoter mapping and deletion analysis of the ipaH9.8. virA, and ospC1 promoters identified a 17-bp motif, the MxiE box, which overlaps the -35 region and is essential for the activation of these promoters. The presence of eight MxiE boxes on the virulence plasmid suggests that 11 genes encoding secreted proteins may be regulated by the activity of secretion. We also present evidence that at least one ipaH gene that is carried by the chromosome is controlled by MxiE and IpgC.

This article has been cited by other articles:

• Pilonieta, M. C., Munson, G. P. (2008). The Chaperone IpgC Copurifies with the Virulence Regulator MxiE. J. Bacteriol. 190: 2249-2251 [Abstract] [Full Text]  
• Schroeder, G. N., Hilbi, H. (2008). Molecular Pathogenesis of Shigella spp.: Controlling Host Cell Signaling, Invasion, and Death by Type III Secretion. Clin. Microbiol. Rev. 21: 134-156 [Abstract] [Full Text]  
• Miura, M., Terajima, J., Izumiya, H., Mitobe, J., Komano, T., Watanabe, H. (2006). OspE2 of Shigella sonnei Is Required for the Maintenance of Cell Architecture of Bacterium-Infected Cells.. Infect. Immun. 74: 2587-2595 [Abstract] [Full Text]  
• Santapaola, D., Del Chierico, F., Petrucca, A., Uzzau, S., Casalino, M., Colonna, B., Sessa, R., Berlutti, F., Nicoletti, M. (2006). Apyrase, the Product of the Virulence Plasmid-Encoded phoN2 (apy) Gene of Shigella flexneri, Is Necessary for Proper Unipolar IcsA Localization and for Efficient Intercellular Spread. J. Bacteriol. 188: 1620-1627 [Abstract] [Full Text]  
• Gall, T. L., Mavris, M., Martino, M. C., Bernardini, M. L., Denamur, E., Parsot, C. (2005). Analysis of virulence plasmid gene expression defines three classes of effectors in the type III secretion system of Shigella flexneri. Microbiology 151: 951-962 [Abstract] [Full Text]  
• Lucchini, S., Liu, H., Jin, Q., Hinton, J. C. D., Yu, J. (2005). Transcriptional Adaptation of Shigella flexneri during Infection of Macrophages and Epithelial Cells: Insights into the Strategies of a Cytosolic Bacterial Pathogen. Infect. Immun. 73: 88-102 [Abstract] [Full Text]  
• Walker, K. A., Miller, V. L. (2004). Regulation of the Ysa Type III Secretion System of Yersinia enterocolitica by YsaE/SycB and YsrS/YsrR. J. Bacteriol. 186: 4056-4066 [Abstract] [Full Text]  
• Cunnac, S., Boucher, C., Genin, S. (2004). Characterization of the cis-Acting Regulatory Element Controlling HrpB-Mediated Activation of the Type III Secretion System and Effector Genes in Ralstonia solanacearum. J. Bacteriol. 186: 2309-2318 [Abstract] [Full Text]