This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Mellies, J. L.
Right arrow Articles by Galligan, D. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mellies, J. L.
Right arrow Articles by Galligan, D. C.

 Previous Article  |  Next Article 

Journal of Bacteriology, April 2007, p. 2863-2872, Vol. 189, No. 7
0021-9193/07/$08.00+0     doi:10.1128/JB.01859-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

SOS Regulation of the Type III Secretion System of Enteropathogenic Escherichia coli{triangledown}

Jay L. Mellies,1* Kenneth R. Haack,1 and Derek C. Galligan2

Biology Department, Reed College, 3203 S.E. Woodstock Blvd., Portland, Oregon 97202,1 Department of Laboratory Medicine, UCSF 0874 SFGH Bldg. 80, Wd. 84, 1001 Potrero Ave., San Francisco, California 941102

Received 11 December 2006/ Accepted 8 January 2007

Genomes of bacterial pathogens contain and coordinately regulate virulence-associated genes in order to cause disease. Enteropathogenic Escherichia coli (EPEC), a major cause of watery diarrhea in infants and a model gram-negative pathogen, expresses a type III secretion system (TTSS) that is encoded by the locus of enterocyte effacement (LEE) and is necessary for causing attaching and effacing intestinal lesions. Effector proteins encoded by the LEE and in cryptic prophage are injected into the host cell cytoplasm by the TTTS apparatus, ultimately leading to diarrhea. The LEE is comprised of multiple polycistronic operons, most of which are controlled by the global, positive regulator Ler. Here we demonstrated that the LEE2 and LEE3 operons also responded to SOS signaling and that this regulation was LexA dependent. As determined by a DNase I protection assay, purified LexA protein bound in vitro to a predicted SOS box located in the divergent, overlapping LEE2/LEE3 promoters. Expression of the lexA1 allele, encoding an uncleavable LexA protein in EPEC, resulted in reduced secretion, particularly in the absence of the Ler regulator. Finally, we obtained evidence that the cryptic phage-located nleA gene encoding an effector molecule is SOS regulated. Thus, we demonstrated, for the first time to our knowledge, that genes encoding components of a TTSS are regulated by the SOS response, and our data might explain how a subset of EPEC effector proteins, encoded in cryptic prophages, are coordinately regulated with the LEE-encoded TTSS necessary for their translocation into host cells.

* Corresponding author. Mailing address: Biology Department, Reed College, 3203 S.E. Woodstock Blvd., Portland, OR 97202. Phone: (503) 517-7964. Fax: (503) 777-7773. E-mail: jay.mellies{at}reed.edu.

{triangledown} Published ahead of print on 19 January 2007.

Journal of Bacteriology, April 2007, p. 2863-2872, Vol. 189, No. 7
0021-9193/07/$08.00+0     doi:10.1128/JB.01859-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Tree, J. J., Wang, D., McInally, C., Mahajan, A., Layton, A., Houghton, I., Elofsson, M., Stevens, M. P., Gally, D. L., Roe, A. J. (2009). Characterization of the Effects of Salicylidene Acylhydrazide Compounds on Type III Secretion in Escherichia coli O157:H7. Infect. Immun. 77: 4209-4220 [Abstract] [Full Text]  
  • Mellies, J. L., Larabee, F. J., Zarr, M. A., Horback, K. L., Lorenzen, E., Mavor, D. (2008). Ler interdomain linker is essential for anti-silencing activity in enteropathogenic Escherichia coli. Microbiology 154: 3624-3638 [Abstract] [Full Text]  
  • Garcia-Angulo, V. A., Deng, W., Thomas, N. A., Finlay, B. B., Puente, J. L. (2008). Regulation of Expression and Secretion of NleH, a New Non-Locus of Enterocyte Effacement-Encoded Effector in Citrobacter rodentium. J. Bacteriol. 190: 2388-2399 [Abstract] [Full Text]  
  • Mellies, J. L., Barron, A. M. S., Carmona, A. M. (2007). Enteropathogenic and Enterohemorrhagic Escherichia coli Virulence Gene Regulation. Infect. Immun. 75: 4199-4210 [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»