The rpoE operon regulates heat stress response in Burkholderia pseudomallei.
Burkholderia pseudomallei is a gram-negative bacterium and the causative agent of melioidosis, one of the important lethal diseases in tropical regions. In this article, we demonstrate the crucial role of the B. pseudomallei rpoE locus in the response to heat stress. The rpoE operon knockout mutant exhibited growth retardation and reduced survival when exposed to a high temperature. Expression analysis using rpoH promoter-lacZ fusion revealed that heat stress induction of rpoH, which encodes heat shock sigma factor (sigma(H)), was abolished in the B. pseudomallei rpoE mutant. Analysis of the rpoH promoter region revealed sequences sharing high homology to the consensus sequence of sigma(E)-dependent promoters. Moreover, the putative heat-induced sigma(H)-regulated heat shock proteins (i.e. GroEL and HtpG) were also absent in the rpoE operon mutant. Altogether, our data suggest that the rpoE operon regulates B. pseudomallei heat stress response through the function of rpoH.
Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Muthita
M
Vanaporn
Paiboon
P
Vattanaviboon
Visith
V
Thongboonkerd
Sunee
S
Korbsrisate
D001426:Bacterial Proteins / Q000502:physiology; D016957:Burkholderia pseudomallei / Q000235:genetics / Q000502:physiology*; D018834:Chaperonin 60 / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D018841:HSP90 Heat-Shock Proteins / Q000502:physiology; D006360:Heat-Shock Proteins / Q000502:physiology; D018869:Heat-Shock Response; D006358:Hot Temperature; D009876:Operon; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012808:Sigma Factor / Q000502:physiology*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D018834:Chaperonin 60; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; C069774:heat-shock sigma factor 32; C063202:sporulation-specific sigma factors; C066720:HtpG protein, bacteria