Regulation of motility in Erwinia carotovora subsp. carotovora: quorum-sensing signal controls FlhDC, the global regulator of flagellar and exoprotein genes, by modulating the production of RsmA, an RNA-binding protein.
Mol Plant Microbe Interact
; 23(10): 1316-23, 2010 Oct.
Article
em En
| MEDLINE
| ID: mdl-20831410
ABSTRACT
Erwinia carotovora subsp. carotovora causes soft-rotting (tissue-macerating) disease in many plants and plant organs. Although pectinases are the primary determinants of virulence, several ancillary factors that augment bacterial virulence have also been identified. One such factor is bacterial motility. Flagellum formation and bacterial movement are regulated in many enterobacteria, including E. carotovora subsp. carotovora, by FlhDC, the master regulator of flagellar genes and FliA, a flagellum-specific σ factor. We document here that motility of E. carotovora subsp. carotovora is positively regulated by the quorum-sensing signal, N-acylhomoserine lactone (AHL), and negatively regulated by RsmA, a post-transcriptional regulator. RsmA, an RNA-binding protein, causes translational repression and promotes RNA decay. Our data show that RsmA negatively regulates flhDC and fliA expression. Moreover, the chemical stabilities of transcripts of these genes are greater in an RsmA- mutant than in RsmA+ bacteria. These observations contrast with positive regulation of flhDC and motility by CsrA (=RsmA) in Escherichia coli. In the absence of AHL, the AHL receptors ExpR1/ExpR2 (=AhlR) in Erwinia carotovora subsp. carotovora negatively regulate motility and expression of flhDC and fliA by activating RsmA production. In the presence of AHL, regulatory effects of ExpR1/ExpR2 are neutralized, resulting in reduced levels of rsmA expression and enhanced motility.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas Repressoras
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Proteínas de Bactérias
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Transdução de Sinais
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Regulação Bacteriana da Expressão Gênica
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Proteínas de Ligação a RNA
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Pectobacterium carotovorum
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Percepção de Quorum
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Flagelos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Mol Plant Microbe Interact
Assunto da revista:
BIOLOGIA MOLECULAR
/
BOTANICA
/
MICROBIOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos