This Article Full Text Full Text (PDF) Other Versions of this Article: JB.01714-06v1 189/5/1627    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 Bodero, M. D. Articles by Munson, G. P. Search for Related Content PubMed PubMed Citation Articles by Bodero, M. D. Articles by Munson, G. P.

 Previous Article  |  Next Article 

Journal of Bacteriology, March 2007, p. 1627-1632, Vol. 189, No. 5
0021-9193/07/$08.00+0     doi:10.1128/JB.01714-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Repression of the Inner Membrane Lipoprotein NlpA by Rns in Enterotoxigenic Escherichia coli

Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, Florida

Received 6 November 2006/ Accepted 14 December 2006

The expression of the inner membrane protein NlpA is repressed by the enterotoxigenic Escherichia coli (ETEC) virulence regulator Rns, a member of the AraC/XylS family. The Rns homologs CfaD from ETEC and AggR from enteroaggregative E. coli also repress expression of nlpA. In vitro DNase I and potassium permanganate footprinting revealed that Rns binds to a site overlapping the start codon of nlpA, preventing RNA polymerase from forming an open complex at nlpAp. A second Rns binding site between positions –152 and –195 relative to the nlpA transcription start site is not required for repression. NlpA is not essential for growth of E. coli under laboratory conditions, but it does contribute to the biogenesis of outer membrane vesicles. As outer membrane vesicles have been shown to contain ETEC heat-labile toxin, the repression of nlpA may be an indirect mechanism through which the virulence regulators Rns and CfaD limit the release of toxin.

Published ahead of print on 22 December 2006.

This article has been cited by other articles:

• Basturea, G. N., Bodero, M. D., Moreno, M. E., Munson, G. P. (2008). Residues near the Amino Terminus of Rns Are Essential for Positive Autoregulation and DNA Binding. J. Bacteriol. 190: 2279-2285 [Abstract] [Full Text]  
• Pilonieta, M. C., Bodero, M. D., Munson, G. P. (2007). CfaD-Dependent Expression of a Novel Extracytoplasmic Protein from Enterotoxigenic Escherichia coli. J. Bacteriol. 189: 5060-5067 [Abstract] [Full Text]