An alternate route to phosphorylating DegU of Bacillus subtilis using acetyl phosphate.
An alternate route to phosphorylating DegU of Bacillus subtilis using acetyl phosphate.
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DOI：
10.1186/s12866-015-0410-z
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发表时间：
2015-03-31
期刊：
影响因子：
4.2
通讯作者：
Stanley-Wall NR
中科院分区：
文献类型：
--
作者：
Cairns LS;Martyn JE;Bromley K;Stanley-Wall NR
双组分信号转导途径允许细菌感知和响应环境。典型地，这样的途径包括传感器组氨酸激酶和应答调节剂。反应调节因子的磷酸化通常导致其活化，允许蛋白质结合靶启动子元件以调节转录。几种机制用于防止反应调节剂的不适当磷酸化，从而确保特异性反应。在枯草芽孢杆菌中，DegS-DegU双组分系统以依赖于磷酸化反应调节剂DegU的水平的方式控制靶基因的转录。先前的工作已经初步表明，DegU和DegU H12 L（一种显示出增强的磷酰基部分稳定性的DegU变体）可以在不存在激酶DegS的情况下被磷酸化。本文提供的数据表明，DegU H12 L需要天冬氨酸56（D56），即已鉴定的DegU磷酸化位点，才能发挥其活性。通过评估几种公认的DegU调节过程间接测量细胞中DegU-P的水平，表明DegU H12 L在DegS不存在下保留其活性，并且D56的突变产生无活性蛋白。设计用于提高细胞内乙酰磷酸水平的进一步实验表明，在不存在degS的情况下，DegU可以被乙酰磷酸化。此外，所呈现的表型和生物化学实验表明DegU H12 L可以可靠地模拟高水平的磷酸化DegU。乙酰磷酸修饰DegU以及实际上DegU H12 L的能力揭示了DegU磷酸化的额外调节层，当DegS水平低或不存在degS时，这将是相关的。鉴于DegU可以激活或抑制的过程的数量，需要在多个水平上进行广泛的调节，以确保系统不会受到不适当的刺激。DegS具有激酶和磷酸酶活性，我们的研究结果表明DegS的磷酸酶活性对于控制DegU磷酸水平是必不可少的。总体而言，我们有助于我们的理解如何复杂的信号通路DegS-DegU调节B。枯草芽孢杆菌
Two-component signal transduction pathways allow bacteria to sense and respond to the environment. Typically such pathways comprise a sensor histidine kinase and a response regulator. Phosphorylation of the response regulator commonly results in its activation, allowing the protein to bind to target promoter elements to regulate transcription. Several mechanisms are used to prevent inappropriate phosphorylation of the response regulator, thereby ensuring a specific response. In Bacillus subtilis, the DegS-DegU two-component system controls transcription of target genes in a manner dependent on the level of the phosphorylated response regulator, DegU. Previous work has tentatively indicated that DegU, and DegU H12L, a DegU variant which displays enhanced stability of the phosphoryl moiety, can be phosphorylated in the absence of the kinase, DegS. The data presented here reveal that DegU H12L requires aspartic acid 56 (D56), the identified DegU phosphorylation site, for its activity. By indirectly measuring the level of DegU ~ P in the cell by assessment of several well recognised DegU regulated processes it was shown that DegU H12L retains its activity in the absence of DegS, and that mutation of D56 produced an inactive protein. Further experiments designed to raise the level of acetyl phosphate within the cell suggest that DegU can be phosphorylated by acetyl phosphate in the absence of degS. Additionally, the phenotypic and biochemical experiments presented indicate that DegU H12L can reliably mimic high levels of phosphorylated DegU. The ability of acetyl phosphate to modify DegU, and indeed DegU H12L, reveal an additional layer of regulation for DegU phosphorylation that will be relevant when the level of DegS is low or in the absence of degS. Given the number of processes that DegU can activate or inhibit, extensive regulation at a number of levels is required to ensure that the system is not inappropriately stimulated. DegS has both kinase and phosphatase activity and our findings demonstrate that the phosphatase activity of DegS is essential to control the level of DegU phosphate. Overall we contribute to our understanding of how the intricate signalling pathway DegS-DegU is regulated in B. subtilis.
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影响因子：
3.2
作者：
Marlow VL;Porter M;Hobley L;Kiley TB;Swedlow JR;Davidson FA;Stanley-Wall NR
通讯作者：
Stanley-Wall NR
影响因子：
3.2
作者：
Earl, Ashlee M.;Eppinger, Mark;Ravel, Jacques
通讯作者：
Ravel, Jacques
影响因子：
3.6
作者：
Kobayashi, Kazuo
通讯作者：
Kobayashi, Kazuo
DOI：
10.1073/pnas.89.2.718
发表时间：
1992-01-15
影响因子：
11.1
作者：
LUKAT, GS;MCCLEARY, WR;STOCK, JB
通讯作者：
STOCK, JB
影响因子：
11.4
作者：
Aguilar, PS;Hernandez-Arriaga, AM;de Mendoza, D
通讯作者：
de Mendoza, D