Superoxide radical-generating compounds activate a predicted promoter site for paraquat-inducible genes of the Chromobacterium violaceum bacterium in a dose-dependent manner.
The purpose of the present study was to functionally evaluate the influence of superoxide radical-generating compounds on the heterologous induction of a predicted promoter region of open reading frames for paraquat-inducible genes (pqi genes) revealed during genome annotation analyses of the Chromobacterium violaceum bacterium. A 388-bp fragment corresponding to a pqi gene promoter of C. violaceum was amplified using specific primers and cloned into a conjugative vector containing the Escherichia coli lacZ gene without a promoter. Assessments of the expression of the β-galactosidase enzyme were performed in the presence of menadione (MEN) and phenazine methosulfate (PMS) compounds at different final concentrations to evaluate the heterologous activation of the predicted promoter region of interest in C. violaceum induced by these substrates. Under these experimental conditions, the MEN reagent promoted highly significant increases in the expression of the β-galactosidase enzyme modulated by activating the promoter region of the pqi genes at all concentrations tested. On the other hand, significantly higher levels in the expression of the β-galactosidase enzyme were detected exclusively in the presence of the PMS reagent at a final concentration of 50 μg/mL. The findings described in the present study demonstrate that superoxide radical-generating compounds can activate a predicted promoter DNA motif for pqi genes of the C. violaceum bacterium in a dose-dependent manner.
Colegiado de Ciências Biológicas, Centro de Ciências Agrárias, Universidade Federal do Vale do São Francisco, Petrolina, PE, Brasil jane.gabriel@univasf.edu.br.
J E
JE
Gabriel
Campus de Ciências Agrárias, Pontifícia Universidade Católica do Paraná, São José dos Pinhais, PR, Brasil.
E P
EP
Guerra-Slompo
Setor de Ciências Biológicas, Departamento de Bioquímica, Universidade Federal do Paraná, Curitiba, PR, Brasil.
E M
EM
de Souza
Colegiado de Ciências Biológicas, Centro de Ciências Agrárias, Universidade Federal do Vale do São Francisco, Petrolina, PE, Brasil.
F A L
FA
de Carvalho
Campus de Ciências Agrárias, Pontifícia Universidade Católica do Paraná, São José dos Pinhais, PR, Brasil.
H M F
HM
Madeira
Laboratório Nacional de Computação Científica, Petrópolis, RJ, Brasil.
A T R
AT
de Vasconcelos
D002861:Chromobacterium / Q000187:drug effects / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D005798:Genes, Bacterial; D010269:Paraquat / Q000633:toxicity*; D011401:Promoter Regions, Genetic; D013481:Superoxides / Q000378:metabolism*; D001616:beta-Galactosidase / Q000378:metabolism
D013481:Superoxides; D001616:beta-Galactosidase; D010269:Paraquat