Contribution of ClpE to virulence of Streptococcus pneumoniae.
The ATP-dependent caseinolytic proteases (Clp) play a fundamental role in stress tolerance and virulence in many pathogenic bacteria. Although ClpE of Streptococcus pneumoniae is required for growth at high temperatures, little is known about the role of ClpE in pathogenesis. In this study, we observed that the virulence of the clpE mutant of S. pneumoniae strain D39 was strongly reduced in a mouse intraperitoneal infection model. The clpE mutant also showed substantially reduced adherence to the human lung epithelial carcinoma A549 cell line and human umbilical-vein-derived endothelial cells. The underlying mechanism of virulence attenuation induced by the mutation of clpE was further investigated with real-time RT-PCR and 2-dimensional protein gel analysis. The results indicate that ClpE affects pneumococcal pathogenesis by modulating the expression of some important virulence determinants and metabolism-related factors in S. pneumoniae.
Zhang
Qun
Q
Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, P. R. China.
Xu
Song-Xiao
SX
Wang
Hong
H
Xu
Wen-Chun
WC
Zhang
Xue-Mei
XM
Wu
Kai-Feng
KF
Liu
Lan
L
Yin
Yi-Bing
YB
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000502:physiology*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D017353:Gene Deletion; D015870:Gene Expression; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D006360:Heat-Shock Proteins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D011008:Pneumococcal Infections / Q000209:etiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013296:Streptococcus pneumoniae / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics / Q000502:physiology
D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D006360:Heat-Shock Proteins; D000251:Adenosine Triphosphatases; C118340:ClpE protein, bacteria