ClpP-deletion impairs the virulence of Legionella pneumophila and the optimal translocation of effector proteins

BMC Microbiology

Research Article

Yong-jun Lu¹  Bei-bei Zhao¹  Xiang-hui Li²  Yong-lun Zeng³ 

[1] School of Life Sciences and Biomedical Center, Sun Yat-sen University, No. 135 Xingang road west, 510275, Guangzhou, China;School of Life Sciences and Biomedical Center, Sun Yat-sen University, No. 135 Xingang road west, 510275, Guangzhou, China;Present address: Jiangsu Information Institute of Science and Technology, 210042, Nanjing, China;School of Life Sciences and Biomedical Center, Sun Yat-sen University, No. 135 Xingang road west, 510275, Guangzhou, China;Present address: School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, 999077, Hong Kong, China;

关键词: Legionella pneumophila;    ClpP;    Virulence;    T4BSS;    Effectors;    Substrate;    Translocation;   

DOI  :  10.1186/s12866-016-0790-8

 received in 2016-03-16, accepted in 2016-07-27,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundThe opportunistic bacterial pathogen Legionella pneumophila uses substrate effectors of Dot/Icm type IVB secretion system (T4BSS) to accomplish survival and replication in amoebae cells and mammalian alveolar macrophages. During the conversion between its highly resistant, infectious dormant form and vigorously growing, uninfectious replicative form, L. pneumophila utilizes a complicated regulatory network in which proteolysis may play a significant role. As a highly conserved core protease, ClpP is involved in various cellular processes as well as virulence in bacteria, and has been proved to be required for the expression of transmission traits and cell division of L. pneumophila.ResultsThe clpP-deficient L. pneumophila strain failed to replicate and was digested in the first 3 h post-infection in mammalian cells J774A.1. Further investigation demonstrates that the clpP deficient mutant strain was unable to escape the endosome-lysosomal pathway in host cells. We also found that the clpP deficient mutant strain still expresses T4BSS components, induces contact-dependent cytotoxicity and translocate effector proteins RalF and LegK2, indicating that its T4BSS was overall functional. Interestingly, we further found that the translocation of several effector proteins is significantly reduced without ClpP.ConclusionsThe data indicate that ClpP plays an important role in regulating the virulence and effector translocation of Legionella pneumophila.

【 授权许可】

CC BY   
© The Author(s). 2016