The secreted IpaB and IpaC invasins and their cytoplasmic chaperone IpgC are required for intercellular dissemination of Shigella flexneri
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منابع مشابه
Induction of necrosis in human neutrophils by Shigella flexneri requires type III secretion, IpaB and IpaC invasins, and actin polymerization.
Infection by Shigella flexneri is characterized by infiltration of neutrophils in the intestinal mucosa and by a strong inflammatory reaction. Although neutrophils are constitutively programmed to die by apoptosis, we show that isolated human neutrophils undergo necrosis 2 h after infection with virulent S. flexneri strain M90T but not with the virulence plasmid-cured strain BS176. This was dem...
متن کاملThe Tripartite Type III Secreton of Shigella flexneri Inserts Ipab and Ipac into Host Membranes
Bacterial type III secretion systems serve to translocate proteins into eukaryotic cells, requiring a secreton and a translocator for proteins to pass the bacterial and host membranes. We used the contact hemolytic activity of Shigella flexneri to investigate its putative translocator. Hemolysis was caused by formation of a 25-A pore within the red blood cell (RBC) membrane. Of the five protein...
متن کاملStructural characterization of the N terminus of IpaC from Shigella flexneri.
The primary effector for Shigella invasion of epithelial cells is IpaC, which is secreted via a type III secretion system. We recently reported that the IpaC N terminus is required for type III secretion and possibly other functions. In this study, mutagenesis was used to identify an N-terminal secretion signal and to determine the functional importance of the rest of the IpaC N terminus. The 1...
متن کاملNonpolar mutagenesis of the ipa genes defines IpaB, IpaC, and IpaD as effectors of Shigella flexneri entry into epithelial cells.
A 31-kb fragment of the large virulence plasmid of Shigella flexneri is necessary for bacterial entry into epithelial cells in vitro. One locus of this fragment encodes the IpaA, -B, -C, and -D proteins, which are the dominant antigens of the humoral immune response during shigellosis. To address the role of the ipa genes, which are clustered in an operon, we constructed a selectable cassette t...
متن کاملIpaD of Shigella flexneri is independently required for regulation of Ipa protein secretion and efficient insertion of IpaB and IpaC into host membranes.
Shigella flexneri causes human dysentery after invading the cells of the colonic epithelium. The best-studied effectors of Shigella entry into colonocytes are the invasion plasmid antigens IpaC and IpaB. These proteins are exported via a type III secretion system (TTSS) to form a pore in the host membrane that may allow the translocation of other effectors into the host cytoplasm. TTSS-mediated...
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ژورنال
عنوان ژورنال: Cellular Microbiology
سال: 1999
ISSN: 1462-5814,1462-5822
DOI: 10.1046/j.1462-5822.1999.00019.x