Pseudomonas aeruginosa OspR is an oxidative stress sensing regulator that affects pigment production, antibiotic resistance and dissemination during infection.
Mol Microbiol
; 75(1): 76-91, 2010 Jan.
Article
em En
| MEDLINE
| ID: mdl-19943895
Oxidative stress is one of the main challenges bacteria must cope with during infection. Here, we identify a new oxidative stress sensing and response ospR (oxidative stress response and pigment production Regulator) gene in Pseudomonas aeruginosa. Deletion of ospR leads to a significant induction in H(2)O(2) resistance. This effect is mediated by de-repression of PA2826, which lies immediately upstream of ospR and encodes a glutathione peroxidase. Constitutive expression of ospR alters pigment production and beta-lactam resistance in P. aeruginosa via a PA2826-independent manner. We further discovered that OspR regulates additional genes involved in quorum sensing and tyrosine metabolism. These regulatory effects are redox-mediated as addition of H(2)O(2) or cumene hydroperoxide leads to the dissociation of OspR from promoter DNA. A conserved Cys residue, Cys-24, plays the major role of oxidative stress sensing in OspR. The serine substitution mutant of Cys-24 is less susceptible to oxidation in vitro and exhibits altered pigmentation and beta-lactam resistance. Lastly, we show that an ospR null mutant strain displays a greater capacity for dissemination than wild-type MPAO1 strain in a murine model of acute pneumonia. Thus, OspR is a global regulator that senses oxidative stress and regulates multiple pathways to enhance the survival of P. aeruginosa inside host.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pseudomonas aeruginosa
/
Proteínas Repressoras
/
Estresse Fisiológico
/
Regulação Bacteriana da Expressão Gênica
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Mol Microbiol
Assunto da revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos