Linked Life Data

9632252

Source:http://linkedlifedata.com/resource/pubmed/id/9632252

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-9-24
pubmed:databankReference
pubmed:abstractText
Many bacteria sense an appropriate growth condition or a critical population density for gene expression by producing acylhomoserine lactones (acyl-HSLs) that act as intercellular autoinduction signals. We recently showed that, in Ralstonia (Pseudomonas) solanacearum, a phytopathogenic bacterium, acyl-HSL production requires soll, which encodes a putative acyl-HSL synthase, and that its expression is positively regulated by the acyl-HSL-responsive SolR transcriptional regulator. This acyl-HSL-dependent autoinduction system is noteworthy because (i) it is regulated by a 'higher level' autoinducer system (responsive to 3-hydroxypalmitic acid methyl ester) via PhcA, a LysR-type transcriptional regulator and (ii) acyl-HSL production requires two additional unlinked loci. As reported here, cloning and sequencing of one of these other loci revealed that it encodes a homologue of RpoS, an alternative sigma factor (sigmaS) that in other bacteria activates gene expression during stationary phase or in response to stress conditions. R. solanacearum RpoS (RpoS(Rso)) was demonstrated to function as a sigma factor because when introduced in trans into an Escherichia coli rpoS mutant it largely restored expression of the RpoS-dependent bolAp1 gene. Mutation of rpoS(Rso) in R. solanacearum reduced survival during starvation and low pH conditions, but did not affect survival during exposure to hydrogen peroxide, high osmolarity or high temperature. This mutant was also altered in its production of several virulence factors and wilted tomato plants several days more slowly than the wild-type parent. Transcription of solR and soll were decreased in an rpoS(Rso) background (thereby reducing acyl-HSL production), but neither mutations in solR, soll or phcA nor addition of acyl-HSLs affected rpoS(Rso) expression. Therefore, in R. solanacearum the acyl-HSL-dependent autoinduction system is controlled both by a second autoinduction system and by the RpoS(Rso) sigma factor.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
475-86
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
An RpoS (sigmaS) homologue regulates acylhomoserine lactone-dependent autoinduction in Ralstonia solanacearum.
pubmed:affiliation
Department of Plant Pathology, University of Georgia, Athens 30602, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't