1. ExsB Is Required for Correct Assembly of the Pseudomonas aeruginosaType III Secretion Apparatus in the Bacterial Membrane and Full Virulence In Vivo
- Author
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Perdu, Caroline, Huber, Philippe, Bouillot, Stéphanie, Blocker, Ariel, Elsen, Sylvie, Attrée, Ina, and Faudry, Eric
- Abstract
ABSTRACTPseudomonas aeruginosais responsible for high-morbidity infections of cystic fibrosis patients and is a major agent of nosocomial infections. One of its most potent virulence factors is a type III secretion system (T3SS) that injects toxins directly into the host cell cytoplasm. ExsB, a lipoprotein localized in the bacterial outer membrane, is one of the components of this machinery, of which the function remained elusive until now. The localization of the exsBgene within the exsCEBAregulatory gene operon suggested an implication in the T3SS regulation, while its similarity with yscWfrom Yersiniaspp. argued in favor of a role in machinery assembly. The present work shows that ExsB is necessary for full in vivovirulence of P. aeruginosa. Furthermore, the requirement of ExsB for optimal T3SS assembly and activity is demonstrated using eukaryotic cell infection and in vitroassays. In particular, ExsB promotes the assembly of the T3SS secretin in the bacterial outer membrane, highlighting the molecular role of ExsB as a pilotin. This involvement in the regulation of the T3S apparatus assembly may explain the localization of the ExsB-encoding gene within the regulatory gene operon. more...
- Published
- 2015
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