A Role for the SmpB-SsrA System in Yersinia pseudotuberculosis Pathogenesis

PLoS Pathogens

A. Wali Karzai¹  Nihal A Okan¹  James B Bliska² 

[1] Department of Biochemistry and Cell Biology, and Center for Infectious Diseases, Stony Brook University, Stony Brook, New York, United States of America;Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America

关键词: Yersinia pseudotuberculosis;    Messenger RNA;    Pathogen motility;    Mutant strains;    Ribosomes;    Host cells;    Secretion;    Flagella;   

DOI  :  10.1371/journal.ppat.0020006

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Yersinia utilizes a sophisticated type III secretion system to enhance its chances of survival and to overcome the host immune system. SmpB (small protein B) and SsrA (small stable RNA A) are components of a unique bacterial translational control system that help maintain the bacterial translational machinery in a fully operational state. We have found that loss of the SmpB-SsrA function causes acute defects in the ability of Yersinia pseudotuberculosis to survive in hostile environments. Most significantly, we show that mutations in smpB-ssrA genes render the bacterium avirulent and unable to cause mortality in mice. Consistent with these observations, we show that the mutant strain is unable to proliferate in macrophages and exhibits delayed Yop-mediated host cell cytotoxicity. Correspondingly, we demonstrate that the smpB-ssrA mutant suffers severe deficiencies in expression and secretion of Yersinia virulence effector proteins, and that this defect is at the level of transcription. Of further interest is the finding that the SmpB-SsrA system might play a similar role in the related type III secretion system that governs flagella assembly and bacterial motility. These findings highlight the significance of the SmpB-SsrA system in bacterial pathogenesis, survival under adverse environmental conditions, and motility.

【 授权许可】

CC BY