| Autor: |
Teh MY; Discipline of Microbiology and Immunology, School of Molecular and Biomedical Science, University of Adelaide, Adelaide 5005, Australia., Tran ENH; Discipline of Microbiology and Immunology, School of Molecular and Biomedical Science, University of Adelaide, Adelaide 5005, Australia., Morona R; Discipline of Microbiology and Immunology, School of Molecular and Biomedical Science, University of Adelaide, Adelaide 5005, Australia. |
| Jazyk: |
angličtina |
| Zdroj: |
Microbiology (Reading, England) [Microbiology (Reading)] 2012 Nov; Vol. 158 (Pt 11), pp. 2835-2850. Date of Electronic Publication: 2012 Aug 30. |
| DOI: |
10.1099/mic.0.062471-0 |
| Abstrakt: |
The Shigella flexneri IcsA (VirG) protein is a polarly distributed autotransporter protein. IcsA functions as a virulence factor by interacting with the host actin regulatory protein N-WASP, which in turn activates the Arp2/3 complex, initiating actin polymerization. Formation of F-actin comet tails allows bacterial cell-to-cell spreading. Although various accessory proteins such as periplasmic chaperones and the β-barrel assembly machine (BAM) complex have been shown to be involved in the export of IcsA, the IcsA translocation mechanism remains to be fully elucidated. A putative autochaperone (AC) region (amino acids 634-735) located at the C-terminal end of the IcsA passenger domain, which forms part of the self-associating autotransporter (SAAT) domain, has been suggested to be required for IcsA biogenesis, as well as for N-WASP recruitment, based on mutagenesis studies. IcsA(i) proteins with linker insertion mutations within the AC region have a significant reduction in production and are defective in N-WASP recruitment when expressed in smooth LPS (S-LPS) S. flexneri. In this study, we have found that the LPS O antigen plays a role in IcsA(i) production based on the use of an rmlD (rfbD) mutant having rough LPS (R-LPS) and a novel assay in which O antigen is depleted using tunicamycin treatment and then regenerated. In addition, we have identified a new N-WASP binding/interaction site within the IcsA AC region. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
