Bimodal Expression of the Salmonella Typhimurium spv Operon.
Genetics
; 210(2): 621-635, 2018 10.
Article
em En
| MEDLINE
| ID: mdl-30143595
ABSTRACT
The well-studied spv operon of Salmonellatyphimurium is important for causing full virulence in mice and both the regulation and function of the Spv proteins have been characterized extensively over the past several decades. Using quantitative single-cell fluorescence microscopy, we demonstrate the spv regulon to display a bimodal expression pattern that originates in the bimodal expression of the SpvR activator. The spv expression pattern is influenced by growth conditions and the specific Styphimurium strain used, but does not require Salmonella-specific virulence regulators. By monitoring real-time promoter kinetics, we reveal that SpvA has the ability to impart negative feedback on spvABCD expression without affecting spvR expression. Together, our data suggest that the SpvA protein counteracts the positive feedback loop imposed by SpvR, and could thus be responsible for dampening spvABCD expression and coordinating virulence protein production in time. The results presented here yield new insights in the intriguing regulation of the spv operon and adds this operon to the growing list of virulence factors exhibiting marked expression heterogeneity in Styphimurium.
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Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Óperon
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Salmonella typhimurium
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Proteínas de Bactérias
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Fatores de Transcrição
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Regulação Bacteriana da Expressão Gênica
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Fatores de Virulência
Idioma:
En
Revista:
Genetics
Ano de publicação:
2018
Tipo de documento:
Article