This Article Full Text (PDF) Other Versions of this Article: IAI.00228-07v1 75/10/4697    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 Gerlach, R. G. Articles by Hensel, M. Search for Related Content PubMed PubMed Citation Articles by Gerlach, R. G. Articles by Hensel, M.

 Previous Article  |  Next Article 

Infect. Immun. doi:10.1128/IAI.00228-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Salmonella Pathogenicity Island 4-mediated adhesion is co-regulated with invasion genes in Salmonella enterica

Institute für Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Erlangen, Germany

^* To whom correspondence should be addressed. Email: hensel{at}mikrobio.med.uni-erlangen.de.

	Abstract

Salmonella Pathogenicity Island 4 (SPI4) encodes a type I secretion system (T1SS) and the cognate substrate protein SiiE. We have recently demonstrated that SiiE is a giant non-fimbrial adhesin involved in the adhesion of S. enterica serovar Typhimurium to polarized epithelial cells. We also observed that under in vitro culture conditions, the synthesis and secretion of SiiE coincided with the activation of Salmonella invasion genes. These observations prompted us to investigate the regulation of SPI4 genes in detail. A novel approach for generation of reporter gene fusions was employed to generate single copy chromosomal fusions to various genes within SPI4 and expression of these fusions was investigated. We analyzed the regulation of SPI4 genes and the role of various regulatory systems for SPI4 expression. Our data show that the expression of SPI4 genes is co-regulated with SPI1 invasion genes by the global regulator SirA. Expression of a SPI4 gene was also reduced in the absence of HilA, the central local regulator of SPI1 gene expression. Both SirA and HilA functions were required for the secretion of SiiE and the SPI4-mediated adhesion. Our data demonstrate that SPI4-mediated adhesion as well as SPI1-mediated invasion are tightly co-regulated by the same regulatory circuits and induced under similar environmental conditions.

This article has been cited by other articles:

• Main-Hester, K. L., Colpitts, K. M., Thomas, G. A., Fang, F. C., Libby, S. J. (2008). Coordinate Regulation of Salmonella Pathogenicity Island 1 (SPI1) and SPI4 in Salmonella enterica Serovar Typhimurium. Infect. Immun. 76: 1024-1035 [Abstract] [Full Text]