Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1997-2-3
pubmed:abstractText
In Pseudomonas aeruginosa, the production of many virulence factors and secondary metabolites is regulated in concert with cell density through quorum sensing. Two quorum-sensing regulons have been identified in which the LuxR homologues LasR and RhlR are activated by N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) and N-butanoyl-L-homoserine lactone (BHL) respectively. The lasR and rhlR genes are linked to the luxl homologues lasl and rhll, which are responsible for synthesis of OdDHL and BHL, respectively. As lasRl and rhlRl are both involved in regulating synthesis of exoenzymes such as elastase, we sought to determine the nature of their interrelationship. By using lacZ transcriptional fusions in both homologous (P. aeruginosa) and heterologous (Escherichia coli) genetic backgrounds we provide evidence that (i) lasR is expressed constitutively throughout the growth cycle, (ii) rhlR expression is regulated by LasR/OdDHL, and (iii) that RhlR/BHL regulates rhll. We also show that expression of the stationary-phase sigma factor gene rpoS is abolished in a P. aeruginosa lasR mutant and in the pleiotropic BHL-negative mutant PANO67. Furthermore, our data reveal that kin E. coli, an rpoS-lacZ fusion is regulated directly by RhlR/BHL. Taken together, these results indicate that P. aeruginosa employs a multilayered hierarchical quorum-sensing cascade involving RhlR/BHL and LasR/OdDHL, interlinked via RpoS, to integrate the regulation of virulence determinants and secondary metabolites with adaptation and survival in the stationary phase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1137-46
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
A hierarchical quorum-sensing cascade in Pseudomonas aeruginosa links the transcriptional activators LasR and RhIR (VsmR) to expression of the stationary-phase sigma factor RpoS.
pubmed:affiliation
Laboratoire d'Ingéniérie et Dynamique des Systèmes Membranaires, Centre National de la Recherche Scientifique, Marseille, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't