Microarray analysis of the Ler regulon in enteropathogenic and enterohaemorrhagic Escherichia coli strains

Bingle, Lewis, Constantinidou, Chrystala, Shaw, Robert K., Islam, Shahidul, Patel, Mala, Snyder, Lori A. S., Lee, David J., Penn, Charles W., Busby, Stephen J. W. and Pallen, Mark J, (2014) Microarray analysis of the Ler regulon in enteropathogenic and enterohaemorrhagic Escherichia coli strains. PLOS One, 9 (1). e80160. ISSN 1932-6203

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Abstract

The type III protein secretion system is an important pathogenicity factor of enteropathogenic and enterohaemorrhagic Escherichia coli pathotypes. The genes encoding this apparatus are located on a pathogenicity island (the locus of enterocyte effacement) and are transcriptionally activated by the master regulator Ler. In each pathotype Ler is also known to regulate genes located elsewhere on the chromosome, but the full extent of the Ler regulon is unclear, especially for enteropathogenic E. coli. The Ler regulon was defined for two strains of E. coli: E2348/69 (enteropathogenic) and EDL933 (enterohaemorrhagic) in mid and late log phases of growth by DNA microarray analysis of the transcriptomes of wild-type and ler mutant versions of each strain. In both strains the Ler regulon is focused on the locus of enterocyte effacement – all major transcriptional units of which are activated by Ler, with the sole exception of the LEE1 operon during mid-log phase growth in E2348/69. However, the Ler regulon does extend more widely and also includes unlinked pathogenicity genes: in E2348/69 more than 50 genes outside of this locus were regulated, including a number of known or potential pathogenicity determinants; in EDL933 only 4 extra-LEE genes, again including known pathogenicity factors, were activated. In E2348/69, where the Ler regulon is clearly growth phase dependent, a number of genes including the plasmid-encoded regulator operon perABC, were found to be negatively regulated by Ler. Negative regulation by Ler of PerC, itself a positive regulator of the ler promoter, suggests a negative feedback loop involving these proteins.

Item Type: Article
Subjects: Sciences > Biomedical Sciences
Sciences > Health Sciences
Sciences > Pharmacy and Pharmacology
Divisions: Faculty of Applied Sciences
Faculty of Applied Sciences > Department of Pharmacy Health and Wellbeing
Health Sciences and Wellbeing Beacon
Depositing User: Hannah Dodd
Date Deposited: 10 Jul 2014 08:31
Last Modified: 23 Sep 2017 17:44
URI: http://sure.sunderland.ac.uk/id/eprint/5031

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