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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1993-11-9
pubmed:abstractText
A large plasmid-encoded protein, VirG, on the bacterial surface is essential for the spreading of Shigella by eliciting polar deposition of filamentous actin in the cytoplasm of epithelial cells. VirG expression from the large plasmid is diminished greatly when it is introduced into Escherichia coli K-12 from Shigella. In an attempt to identify factors affecting VirG expression, we found that the absence of the ompT gene, encoding outer membrane protease OmpT, restored full production of VirG protein to E. coli K-12. Conversely, upon introduction of the ompT gene of E. coli K-12 into Shigella, spreading ability was completely abolished, probably because of the proteolytic degradation of VirG protein by OmpT. Analysis of the DNA sequence of the ompT region indicated that the absence of the ompT gene occurred in Shigella and enteroinvasive E. coli strains, and that the absent DNA segment corresponded to a remnant lambdoid phage structure found in E. coli K-12, which encompasses a 21 kb DNA segment spanning from argU through to the ompT genes. Since ompT is located near purE in E. coli K-12 and a virulence locus for provoking keratoconjunctivitis in the eyes of guinea-pigs, named kcpA, is located near purE in S. flexneri, and the two loci are involved in VirG expression, the KcpA- mutants of S. flexneri 2a constructed were examined for correlation between acquisition of ompT and VirG degradation. Our data suggest that the previous recognition of a kcpA locus in S. flexneri is the result of transfer of the ompT gene from E. coli K-12, giving rise to a KcpA- phenotype. These results indicate that the lack of OmpT protease confers upon Shigella the ability to spread into adjacent epithelial cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
459-68
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
The absence of a surface protease, OmpT, determines the intercellular spreading ability of Shigella: the relationship between the ompT and kcpA loci.
pubmed:affiliation
National Institute for Leprosy Research, Tokyo, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't