Linked Life Data

11679074

Source:http://linkedlifedata.com/resource/pubmed/id/11679074

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-10-26
pubmed:abstractText
Adaptive responses of bacteria that involve sensing the presence of other bacteria are often critical for proliferation and the expression of virulence characteristics. The autoinducer II (AI-2) pathway has recently been shown to be a mechanism for sensing other bacteria that is highly conserved among diverse bacterial species, including Gram-positive pathogens. However, a role for this pathway in the regulation of virulence factors in Gram-positive pathogens has yet to be established. In this study, we have inactivated luxS, an essential component of the AI-2 pathway, in the Gram-positive pathogen Streptococcus pyogenes. Analyses of the resulting mutants revealed the aberrant expression of several virulence properties that are regulated in response to growth phase, including enhanced haemolytic activity, and a dramatic reduction in the expression of secreted proteolytic activity. This latter defect was associated with a reduced ability to secrete and process the precursor of the cysteine protease (SpeB) as well as a difference in the timing of expression of the protease. Enhanced haemolytic activity of the luxS strain was also shown to be linked with an increased expression of the haemolysin S-associated gene sagA. Disruptions of luxS in these mutants also produced a media-dependent growth defect. Finally, an allelic replacement analysis of an S. pyogenes strain with a naturally occurring insertion of IS1239 in luxS suggested a mechanism for modulation of virulence during infection. Results from this study suggest that luxS makes an important contribution to the regulation of S. pyogenes virulence factors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Carbon-Sulfur Lyases, http://linkedlifedata.com/resource/pubmed/chemical/Culture Media, http://linkedlifedata.com/resource/pubmed/chemical/Cysteine Endopeptidases, http://linkedlifedata.com/resource/pubmed/chemical/Fungal Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Homoserine, http://linkedlifedata.com/resource/pubmed/chemical/Lactones, http://linkedlifedata.com/resource/pubmed/chemical/LuxS protein, Bacteria, http://linkedlifedata.com/resource/pubmed/chemical/N-octanoylhomoserine lactone, http://linkedlifedata.com/resource/pubmed/chemical/SAGA protein, Emericella nidulans, http://linkedlifedata.com/resource/pubmed/chemical/Streptolysins, http://linkedlifedata.com/resource/pubmed/chemical/streptolysin S, http://linkedlifedata.com/resource/pubmed/chemical/streptopain
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
145-57
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Mutation of luxS affects growth and virulence factor expression in Streptococcus pyogenes.
pubmed:affiliation
Department of Molecular Microbiology, Washington University School of Medicine, Box 8230, St Louis, MO 63110-1093, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.