Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1998-2-24
pubmed:abstractText
Virulence is a multifactorial trait which depends on the coordinated expression of many bacterial products, hence it is to be expected that the regulatory circuits that control the relevant genetic determinants are somehow interconnected. Two pleiotropic regulatory elements acting at different levels, the transcription factor PrfA which controls virulence gene expression and the potential chaperone ClpC which is involved in tolerance to environmental stress, are required for Listeria monocytogenes survival within the host. We analyzed the influence of PrfA on clpC expression in L. monocytogenes. clpC transcription is maximal under heat-shock conditions, i.e. at 42 degrees C, and is very weak or undetectable at 37 degrees C. In a prfA* mutant which constitutively overexpresses PrfA and PrfA-dependent virulence genes, clpC transcription dropped to basal levels during exponential growth at 42 degrees C. This repression was not observed during stationary phase, indicating growth phase-dependent regulation of clpC. Culture in charcoal-treated medium, which triggers in wild-type strains the transcriptional activation of the PrfA regulon, also caused a strong downregulation of clpC. Moreover, in a prfA deletion mutant, clpC transcription during exponential growth at 37 degrees C was clearly enhanced, reaching the same high levels of the wild-type at 42 degrees C. Overall, our results indicate that clpC expression is negatively controlled at the transcriptional level, directly or indirectly, by the central virulence regulator PrfA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0378-1097
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
158
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
45-50
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Evidence for expressional crosstalk between the central virulence regulator PrfA and the stress response mediator ClpC in Listeria monocytogenes.
pubmed:affiliation
Unidad de Microbiología e Immunología, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't