Phosphorylation and RsbX-dependent dephosphorylation of RsbR in the RsbR-RsbS complex of Bacillus subtilis
Phosphorylation and RsbX-dependent dephosphorylation of RsbR in the RsbR-RsbS complex of Bacillus subtilis
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DOI：
10.1128/jb.186.20.6830-6836.2004
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发表时间：
2004-10-01
影响因子：
3.2
通讯作者：
Delumeau, O
中科院分区：
文献类型：
--
作者：
Chen, CC;Yudkin, MD;Delumeau, O
在控制sigma（B）活性的途径中，RsbR-RsbS复合物通过捕获枯草芽孢杆菌的sigma（B）的正调节因子RsbT而起重要作用。我们提出，在应激开始时，RsbR变得磷酸化，导致RsbT对RsbS的活性增强。然后RsbT自由地与RsbU相互作用并激活RsbU，RsbU进而最终激活sigma（B）。在这项研究中，纯化的蛋白质，我们使用突变体RsbR蛋白分析其磷酸化苏氨酸残基的作用。结果表明，RsbR中的两个RsbT可磷酸化的苏氨酸残基（T171和T205）中的任一个的磷酸化增强了RsbT对RsbS的激酶活性。然而，似乎RsbT优先磷酸化T171。我们还提出了体外证据，确定RsbX作为一个潜在的磷酸酶RsbR T205。
In the pathway that controls sigma(B) activity, the RsbR-RsbS complex plays an important role by trapping RsbT, a positive regulator of sigma(B) of Bacillus subtilis. We have proposed that at the onset of stress, RsbR becomes phosphorylated, resulting in an enhanced activity of RsbT towards RsbS. RsbT is then free to interact with and activate RsbU, which in turn ultimately activates sigma(B). In this study with purified proteins, we used mutant RsbR proteins to analyze the role of its phosphorylatable threonine residues. The results show that the phosphorylation of either of the two RsbT-phosphorylatable threonine residues (T171 and T205) in RsbR enhanced the kinase activity of RsbT towards RsbS. However, it appeared that RsbT preferentially phosphorylates T171. We also present in vitro evidence that identifies RsbX as a potential phosphatase for RsbR T205.