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OpaR and RpoS are positive regulators of a virulence factor PrtA in Vibrio parahaemolyticus.
- Source :
-
Microbiology (Reading, England) [Microbiology (Reading)] 2018 Feb; Vol. 164 (2), pp. 221-231. Date of Electronic Publication: 2017 Dec 19. - Publication Year :
- 2018
-
Abstract
- PrtA is an extracellular serine protease of Vibrio parahaemolyticus and has haemolytic and cytotoxic activities. Many extracellular proteases have been shown to be required for nutrient intake and the infection mechanism of vibrios. In this study, we report that OpaR, a quorum sensing regulator, and RpoS, a general stress response regulator, play important roles in the PrtA regulation pathway. Extracellular protease activity was highest during the late-log growth of Vibrio parahaemolyticus no.93 (VP93). The absence of PrtA distinctly decreased the extracellular protease activity. Deletion of opaR or rpoS alone reduced PrtA-specific activity of VP93. Quantitative reverse-transcriptase PCR and Western blot analysis suggested that OpaR and RpoS promote PrtA expression at the transcriptional level and affect the amount of extracellular PrtA. A luciferase assay revealed that OpaR regulates prtA on the prtA promoter region. Electrophoretic mobility shift assays indicated that the purified His-OpaR was able to bind specifically to two sequences (PrtA-1 and PrtA-2) of the prtA promoter region. Footprinting analysis showed that OpaR regulates prtA by binding to the promoter region of prtA at positions -269 to -246 and -88 to -68 from the prtA translational start site. Together, the results suggest that PrtA was upregulated by two global regulators, OpaR and RpoS.
- Subjects :
- Bacterial Proteins genetics
Binding Sites
Gene Deletion
Gene Expression Regulation, Bacterial genetics
Genes, Bacterial genetics
Promoter Regions, Genetic
Protein Binding
Sigma Factor genetics
Transcription Factors genetics
Vibrio parahaemolyticus genetics
Vibrio parahaemolyticus pathogenicity
Bacterial Proteins metabolism
Sigma Factor metabolism
Transcription Factors metabolism
Vibrio parahaemolyticus metabolism
Virulence Factors genetics
Virulence Factors metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1465-2080
- Volume :
- 164
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Microbiology (Reading, England)
- Publication Type :
- Academic Journal
- Accession number :
- 29256853
- Full Text :
- https://doi.org/10.1099/mic.0.000591