Regulatory interactions of a virulence-associated serine/threonine phosphatase-kinase pair in Bacillus anthracis.
J Bacteriol
; 192(2): 400-9, 2010 Jan.
Article
em En
| MEDLINE
| ID: mdl-19915022
ABSTRACT
In the current study, we examined the regulatory interactions of a serine/threonine phosphatase (BA-Stp1), serine/threonine kinase (BA-Stk1) pair in Bacillus anthracis. B. anthracis STPK101, a null mutant lacking BA-Stp1 and BA-Stk1, was impaired in its ability to survive within macrophages, and this correlated with an observed reduction in virulence in a mouse model of pulmonary anthrax. Biochemical analyses confirmed that BA-Stp1 is a PP2C phosphatase and dephosphorylates phosphoserine and phosphothreonine residues. Treatment of BA-Stk1 with BA-Stp1 altered BA-Stk1 kinase activity, indicating that the enzymatic function of BA-Stk1 can be influenced by BA-Stp1 dephosphorylation. Using a combination of mass spectrometry and mutagenesis approaches, three phosphorylated residues, T165, S173, and S214, in BA-Stk1 were identified as putative regulatory targets of BA-Stp1. Further analysis found that T165 and S173 were necessary for optimal substrate phosphorylation, while S214 was necessary for complete ATP hydrolysis, autophosphorylation, and substrate phosphorylation. These findings provide insight into a previously undescribed Stp/Stk pair in B. anthracis.
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Base de dados:
MEDLINE
Assunto principal:
Bacillus anthracis
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Proteínas de Bactérias
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Virulência
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Proteínas Serina-Treonina Quinases
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Fosfoproteínas Fosfatases
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article