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Bicarbonate-mediated transcriptional activation of divergent operons by the virulence regulataory protein, RegA, from Citrobacter rodentium

Yang, Ji; Hart, Emily; Tauschek, Marija; Price, Graeme (Dean); Hartland, Elizabeth L; Strugnell, R; Robins-Browne, Roy M

Description

Regulation of virulence gene expression plays a central role in the pathogenesis of enteric bacteria as they encounter diverse environmental conditions in the gastrointestinal tract of their hosts. In this study, we investigated environmental regulation of two putative virulence determinants adcA and kfc by RegA, an AraC/XylS-like regulator, from Citrobacter rodentium, and identified bicarbonate as the environmental signal which induced transcription of adcA and kfc through RegA. Primer...[Show more]

dc.contributor.authorYang, Ji
dc.contributor.authorHart, Emily
dc.contributor.authorTauschek, Marija
dc.contributor.authorPrice, Graeme (Dean)
dc.contributor.authorHartland, Elizabeth L
dc.contributor.authorStrugnell, R
dc.contributor.authorRobins-Browne, Roy M
dc.date.accessioned2015-12-10T22:43:58Z
dc.identifier.issn0950-382X
dc.identifier.urihttp://hdl.handle.net/1885/58398
dc.description.abstractRegulation of virulence gene expression plays a central role in the pathogenesis of enteric bacteria as they encounter diverse environmental conditions in the gastrointestinal tract of their hosts. In this study, we investigated environmental regulation of two putative virulence determinants adcA and kfc by RegA, an AraC/XylS-like regulator, from Citrobacter rodentium, and identified bicarbonate as the environmental signal which induced transcription of adcA and kfc through RegA. Primer extension experiments showed that adcA and kfc were divergently transcribed from σ70 promoters. In vivo and in vitro experiments demonstrated that bicarbonate facilitated and stabilized the binding of RegA to an operator located between the two promoters. The interaction of RegA with its DNA target resulted in the formation of a nucleosome-like structure, which evidently displaced the histone-like proteins, H-NS and StpA, from the adcA and kfc promoter regions, leading to transcriptional derepression. In addition, our results indicated that RegA also behaved as a Class I activator by directly stimulating transcription initiation by RNA polymerase. This is the first report to describe the molecular mechanism by which an environmental chemical stimulates transcription of virulence-associated genes of an enteric pathogen through an AraC/XlyS-like activator.
dc.publisherBlackwell Publishing Ltd
dc.sourceMolecular Microbiology
dc.subjectKeywords: bacterial DNA; bacterial protein; bicarbonate; deoxyribonuclease I; ethoxzolamide; histone; protein adca; protein kfcc; protein regA; RNA polymerase; unclassified drug; article; bacterial virulence; Citrobacter rodentium; controlled study; DNA footprintin
dc.titleBicarbonate-mediated transcriptional activation of divergent operons by the virulence regulataory protein, RegA, from Citrobacter rodentium
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume68
dc.date.issued2008
local.identifier.absfor060501 - Bacteriology
local.identifier.absfor060405 - Gene Expression (incl. Microarray and other genome-wide approaches)
local.identifier.ariespublicationu9204316xPUB440
local.type.statusPublished Version
local.contributor.affiliationYang, Ji, University of Melbourne
local.contributor.affiliationHart, Emily, University of Melbourne
local.contributor.affiliationTauschek, Marija, University of Melbourne
local.contributor.affiliationPrice, Graeme (Dean), College of Medicine, Biology and Environment, ANU
local.contributor.affiliationHartland, Elizabeth L, University of Melbourne
local.contributor.affiliationStrugnell, R, University of Melbourne
local.contributor.affiliationRobins-Browne, Roy M, University of Melbourne
local.description.embargo2037-12-31
local.bibliographicCitation.issue2
local.bibliographicCitation.startpage314
local.bibliographicCitation.lastpage327
local.identifier.doi10.1111/j.1365-2958.2008.06171.x
dc.date.updated2015-12-09T11:18:58Z
local.identifier.scopusID2-s2.0-41049087858
local.identifier.thomsonID000254306200008
CollectionsANU Research Publications

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