Global transcriptional upregulation in the absence of increased translation in Chlamydia during IFNgamma-mediated host cell tryptophan starvation.
Mol Microbiol
; 62(5): 1387-401, 2006 Dec.
Article
em En
| MEDLINE
| ID: mdl-17059564
ABSTRACT
The developmentally regulated intracellular pathogen Chlamydia pneumoniae is a natural tryptophan auxotroph. These organisms survive tryptophan starvation induced by host cell activation with IFNgamma by blocking maturation to the infectious form. In most bacteria, the stringent response is induced during amino acid starvation to promote survival. However, the response of obligate intracellular pathogens, which are predicted to lack stringent responses to amino acid starvation, is poorly characterized. Chlamydial transcription and translation were analysed during IFNgamma-mediated tryptophan starvation using genomic normalization methods, and the data revealed the novel findings that (i) global chlamydial transcription was upregulated; and (ii) protein synthesis was dramatically reduced. These results indicate a dysregulation of developmental gene expression and an uncoupling of transcription from translation. These observations represent an alternative survival strategy for host-adapted obligate intracellular bacterial pathogens that have lost the genes for stringent control during reductive evolution.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transcrição Gênica
/
Biossíntese de Proteínas
/
Triptofano
/
Interferon gama
/
Chlamydophila pneumoniae
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Mol Microbiol
Ano de publicação:
2006
Tipo de documento:
Article