Linked Life Data

11700342

Source:http://linkedlifedata.com/resource/pubmed/id/11700342

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 11
pubmed:dateCreated
2001-11-8
pubmed:databankReference
pubmed:abstractText
A previously unknown protein, designated SvpA (surface virulence-associated protein) and implicated in the virulence of the intracellular pathogen Listeria monocytogenes, was identified. This 64 kDa protein, encoded by svpA, is both secreted in culture supernatants and surface-exposed, as shown by immunogold labelling of whole bacteria with an anti-SvpA antibody. Analysis of the peptide sequence revealed that SvpA contains a leader peptide, a predicted C-terminal transmembrane region and a positively charged tail resembling that of the surface protein ActA, suggesting that SvpA might partially reassociate with the bacterial surface by its C-terminal membrane anchor. An allelic mutant was constructed by disrupting svpA in the wild-type strain LO28. The virulence of this mutant was strongly attenuated in the mouse, with a 2 log decrease in the LD50 and restricted bacterial growth in organs as compared to the wild-type strain. This reduced virulence was not related either to a loss of adherence or to a lower expression of known virulence factors, which remained unaffected in the svpA mutant. It was caused by a restriction of intracellular growth of mutant bacteria. By following the intracellular behaviour of bacteria within bone-marrow-derived macrophages by confocal and electron microscopy studies, it was found that most svpA mutant bacteria remained confined within phagosomes, in contrast to wild-type bacteria which rapidly escaped to the cytoplasm. The regulation of svpA was independent of PrfA, the transcriptional activator of virulence genes in L. monocytogenes. In fact, SvpA was down-regulated by MecA, ClpC and ClpP, which are highly homologous to proteins of Bacillus subtilis forming a regulatory complex controlling the competence state of this saprophyte. The results indicate that: (i) SvpA is a novel factor involved in the virulence of L. monocytogenes, promoting bacterial escape from phagosomes of macrophages; (ii) SvpA is, at least partially, associated with the surface of bacteria; and (iii) SvpA is PrfA-independent and controlled by a MecA-dependent regulatory network.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1350-0872
pubmed:author
pubmed:issnType
Print
pubmed:volume
147
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2913-23
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:11700342-Amino Acid Sequence, pubmed-meshheading:11700342-Animals, pubmed-meshheading:11700342-Bacillus subtilis, pubmed-meshheading:11700342-Bacterial Proteins, pubmed-meshheading:11700342-Cloning, Molecular, pubmed-meshheading:11700342-Gene Expression Regulation, Bacterial, pubmed-meshheading:11700342-Heat-Shock Proteins, pubmed-meshheading:11700342-Listeria monocytogenes, pubmed-meshheading:11700342-Macrophages, pubmed-meshheading:11700342-Membrane Proteins, pubmed-meshheading:11700342-Mice, pubmed-meshheading:11700342-Molecular Sequence Data, pubmed-meshheading:11700342-Mutagenesis, pubmed-meshheading:11700342-Peptide Termination Factors, pubmed-meshheading:11700342-Phagosomes, pubmed-meshheading:11700342-Phenotype, pubmed-meshheading:11700342-Restriction Mapping, pubmed-meshheading:11700342-Sequence Deletion, pubmed-meshheading:11700342-Trans-Activators, pubmed-meshheading:11700342-Virulence
pubmed:year
2001
pubmed:articleTitle
SvpA, a novel surface virulence-associated protein required for intracellular survival of Listeria monocytogenes.
pubmed:affiliation
Laboratoire de Microbiologie, Institut National de la Santé et de la Recherche Médicale U411, Faculté de Médecine Necker-Enfants Malades, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't