Type III secretion study of popN- mutant of Pseudomonas aeruginosa and proteases degradation.
- Author:
Hong-Jiang YANG
1
;
Dong-Sheng WEI
;
Ming-Chun LI
;
Lai-Jun XING
Author Information
1. Tianjin Key Laboratory of Microbial Funitional Genomics, Department of Microbiology, Nankai University, Tianjin 300071, China.
- Publication Type:Journal Article
- MeSH:
ADP Ribose Transferases;
metabolism;
secretion;
Bacterial Proteins;
genetics;
metabolism;
secretion;
Bacterial Toxins;
metabolism;
Gene Expression Regulation, Bacterial;
Mutation;
Peptide Hydrolases;
genetics;
metabolism;
Pore Forming Cytotoxic Proteins;
genetics;
secretion;
Protease Inhibitors;
pharmacology;
Pseudomonas aeruginosa;
genetics;
metabolism;
pathogenicity
- From:
Chinese Journal of Biotechnology
2007;23(5):846-851
- CountryChina
- Language:Chinese
-
Abstract:
Pseudomonas aeruginosa is an important opportunistic human pathogen. It encodes many virulence factors and one of them is type III secretion system (TTSS). Effectors proteins can be delivered into host cells directly by this system, causing necrosis or apoptosis. popN gene is the first gene in the popN operon of TTSS gene cluster. To investigate its function, popN gene deletion mutant was generated in this study, and we found this mutant can secrete effectors proteins constitutively under non-inducting condition in DMEM medium containing serum. The results indicated that PopN is a negative regulator of the TTSS expression. However, no secreted effector proteins were detectable when the popN- mutant was grown in LB medium under non-inducting condition. To investigate the possible reasons, effects of growth status and protease (s) inhibitors on the TTSS were investigated. We present evidences that indicate protease mediated degradation of secreted effector proteins played a key role in the phenotypic inconsistency of popN- mutant.
