Type VI Secretion System Transports Zn2+ to Combat Multiple Stresses and Host Immunity

PLoS Pathogens

Zhao-Qing Luo¹  Wenhan Zhu¹  Yunhong Song²  Tietao Wang²  Gehong Wei²  Yao Wang²  Xihui Shen²  Meiru Si²  Lei Zhang²  Weipeng Zhang²  Fen Gao² 

[1] Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America;State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China

关键词: Zinc;    Secretion systems;    Oxidative stress;    Polymerase chain reaction;    Recombinant proteins;    Intracellular pathogens;    Zinc transporters;    Macrophages;   

DOI  :  10.1371/journal.ppat.1005020

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Type VI secretion systems (T6SSs) are widespread multi-component machineries that translocate effectors into either eukaryotic or prokaryotic cells, for virulence or for interbacterial competition. Herein, we report that the T6SS-4 from Yersinia pseudotuberculosis displays an unexpected function in the transportation of Zn2+ to combat diverse stresses and host immunity. Environmental insults such as oxidative stress induce the expression of T6SS-4 via OxyR, the transcriptional factor that also regulates many oxidative response genes. Zinc transportation is achieved by T6SS-4-mediated translocation of a novel Zn2+-binding protein substrate YezP (YPK_3549), which has the capacity to rescue the sensitivity to oxidative stress exhibited by T6SS-4 mutants when added to extracellular milieu. Disruption of the classic zinc transporter ZnuABC together with T6SS-4 or yezP results in mutants that almost completely lost virulence against mice, further highlighting the importance of T6SS-4 in resistance to host immunity. These results assigned an unconventional role to T6SSs, which will lay the foundation for studying novel mechanisms of metal ion uptake by bacteria and the role of this process in their resistance to host immunity and survival in harmful environments.

【 授权许可】

CC BY