Caractérisation du locus ysa codant un appareil de sécrétion de type III chez les Y. entercocolitica du biotype 1B
(2002)
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- Authors
- Supervisors
- Cornélis, Guy R.
- Abstract
- Bacterial pathogenesis results from the ability of bacteria to established and proliferate in the host. The molecules involved in this colonization process are called virulence factors. In the bacterial world, several virulence factors have been recognized. Among them , molecular machines called type III secretion systems derive from a common ancestor and are horizontally transmitted from a bacterium to another (publication 1). The type III secretion systems consist of cytotoxins, chaperones, regulators, a type III secretion apparatus allowing secretion of cytotoxins across the bacterial envelope, and translocators allowing the cytotoxins to cross the host-cell membrane. <BR> Enteropathogenic Yersinia enterocolitica from 1B biotype possesses two type III secretion systems, one encoded on the pYV virulence plasmid and the other on the chromosome. The Ysc/Yop system encoded on the pYV (annexà allows Y. enterocolitica to escape from the host immune response by blocking phagocytosis mediated by the macrophages. The Ysa/Yop system encoded on the chromosome phylogenetically related to Mxi/Spa and SPI-1 type III secretion system from Shigella flexneri and Salmonella enterica (publication 1). The Ysa/Yop secretion apparatus (publication 2) secretes at least 7 proteins : YspA, YspB, YspC, YspD, YopE, p46 and p44. Although YspB and YspC are homologous to IpaB et IpaC from S. flexneri, their role is different. Proteins p46 and p44 are encoded on the chromosome, but outside the ysa locus. This situation is reminiscent of the SopE proteins of S. enterica which is encoded within a temperate bacteriophage located outside SPI-1, but secreted, via the SPI-1 TTS system (153). The pYV encoded YopE protein was initially characterized as a Ysc substrate (149). The fact that YopE is alos secreted by the Ysa system indicates that there is an interaction between both systems.
- Affiliations
Citations
Foultier, B. (2002). Caractérisation du locus ysa codant un appareil de sécrétion de type III chez les Y. entercocolitica du biotype 1B. https://hdl.handle.net/2078.5/110781