RESUMO
Bacteria utilise Twin arginine translocation (Tat) to deliver folded proteins across the cytoplasmic membrane. Disruption of Tat typically results in pleiotropic effects on e.g. growth, stress resistance, bacterial membrane biogenesis, motility and cell morphology. Further, Tat is coupled to virulence in a range of pathogenic bacteria, including species of Pseudomonas, Legionella, Agrobacterium and Mycobacterium. We have investigated this, for Yersinia, previously unexplored system, and have shown that the Tat pathway is functional and absolutely required for virulence of Yersinia pseudotuberculosis. A range of putative Yersinia Tat substrates have been predicted in silico, which together with the Tat system itself may be interesting targets for future development of antimicrobial treatments. Here we present a brief review of bacterial Tat and discuss our results concerning this system in Yersinia.
Assuntos
Arginina/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Yersinia/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/genética , Transporte Biológico Ativo , Membrana Celular/metabolismo , Genes Bacterianos , Proteínas de Membrana Transportadoras/genética , Dados de Sequência Molecular , Movimento , Óperon , Sinais Direcionadores de Proteínas/genética , Virulência , Yersinia/genética , Yersinia/patogenicidadeRESUMO
Yersinia species pathogenic to humans have been extensively characterized with respect to type III secretion and its essential role in virulence. This study concerns the twin arginine translocation (Tat) pathway utilized by gram-negative bacteria to secrete folded proteins across the bacterial inner membrane into the periplasmic compartment. We have shown that the Yersinia Tat system is functional and required for motility and contributes to acid resistance. A Yersinia pseudotuberculosis mutant strain with a disrupted Tat system (tatC) was, however, not affected in in vitro growth or more susceptible to high osmolarity, oxidative stress, or high temperature, nor was it impaired in type III secretion. Interestingly, the tatC mutant was severely attenuated via both the oral and intraperitoneal routes in the systemic mouse infection model and highly impaired in colonization of lymphoid organs like Peyer's patches and the spleen. Our work highlights that Tat secretion plays a key role in the virulence of Y. pseudotuberculosis.
