title: NaCl concentration in the medium modulates the secretion of active EmpA protease in Vibrio anguillarum at post-transcriptional level.
abstract: OBJECTIVE
  This study focused on the influence of different amounts of NaCl in the medium in Vibrio anguillarum EmpA protease production at both the transcriptional and post-transcriptional levels.
  
  
  RESULTS
  Vibrio anguillarum 975/I was cultivated in cM9 medium with varying concentrations of NaCl: 0·5, 1·5, 3·0%. EmpA protease was monitored in the supernatants by the skim milk test, azocasein assay and Western blot analysis. The empA gene expression was measured by real-time PCR. A mutant strain 975/I defective for the empA gene confirmed the specificity of the response for EmpA protease. Active protease production was induced by 0·5 and 1·5% NaCl-amended media; however, the strain cultivated in 3·0% NaCl was unable to secrete EmpA protease. The quantitative expression of the empA gene was very similar in all tested conditions.
  
  
  CONCLUSIONS
  The NaCl concentration in the medium modulates the secretion of active EmpA protease in V. anguillarum at a post-transcriptional level.
  
  
  CONCLUSIONS
  EmpA protease is one of the most important virulence factors in V. anguillarum. We demonstrated the influence of osmotic changes in the regulation of EmpA protease in the V. anguillarum 975/I strain. This finding has an important impact on the evaluation of factors determining the onset of disease in fish.
authors.affiliation: Institute for Coastal Marine Environment CNR, Messina, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Crisafi
authors.affiliation: Institute for Coastal Marine Environment CNR, Messina, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Denaro
authors.affiliation: Institute for Coastal Marine Environment CNR, Messina, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Yakimov
authors.affiliation: Department of Biological and Environmental Sciences, University of Messina, Messina, Italy.
authors.forename: M R
authors.initials: MR
authors.lastname: Felice
authors.affiliation: Institute for Coastal Marine Environment CNR, Messina, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Giuliano
authors.affiliation: Institute for Coastal Marine Environment CNR, Messina, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Genovese
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry*; D045726:Metalloproteases / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D014733:Vibrio / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D012965:Sodium Chloride; C500552:EmpA protein, Vibrio anguillarum; D045726:Metalloproteases
keywords: Vibrio anguillarum; empA gene expression; modulation; protease; sodium chloride