Gene expression profiling of Yersinia pestis with deletion of lcrG, a known negative regulator for Yop secretion of type III secretion system.
Yersinia pestis injects a set of virulent proteins into the cytosol of eukaryotic cells by a type III secretion system (T3SS). LcrG is a known negative regulator for secretion of Yersinia outer-membrane proteins (Yops) by blocking the secretion apparatus (Ysc) from the inner membrane. To further understand the effect of lcrG deletion on Y. pestis T3SS regulation, transcriptional profiles from the DeltalcrG mutant and wild-type Y. pestis strains were compared. The results showed that although the DeltalcrG mutant was markedly attenuated (600-fold increase of LD(50) in s.c. challenged BALB/c mice), transcriptions of almost all the type III genes were upregulated significantly in the DeltalcrG mutant. The immunoblotting analysis of YopM and LcrV demonstrated that their expressions were also increased in the DeltalcrG mutant in comparison to the wild-type strain. We speculate that, in addition to the negative regulation of the Yop secretion, LcrG could possibly play a negative regulatory role in the transcription of T3SS genes through indirect mechanisms. Furthermore, this report also revealed significant transcriptional changes in the genes encoding cell-envelope-related proteins and a virulence-related transcription factor RovA in the DeltalcrG mutant.
Du
Zongmin
Z
Laboratory of Analytical Microbiology, State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing 100071, China.
Tan
Yafang
Y
Yang
Huiying
H
Qiu
Jinfu
J
Qin
Long
L
Wang
Tang
T
Liu
Haihong
H
Bi
Yujing
Y
Song
Yajun
Y
Guo
Zhaobiao
Z
Han
Yanping
Y
Zhou
Dongsheng
D
Wang
Xiaoyi
X
Yang
Ruifu
R
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D005260:Female; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D007928:Lethal Dose 50; D051379:Mice; D008807:Mice, Inbred BALB C; D052899:Pore Forming Cytotoxic Proteins / Q000235:genetics*; D016019:Survival Analysis; D014774:Virulence; D015010:Yersinia pestis / Q000235:genetics / Q000502:physiology*
D001426:Bacterial Proteins; C088009:LcrG protein, Yersinia; D052899:Pore Forming Cytotoxic Proteins