DdcA antagonizes a bacterial DNA damage checkpoint
DdcA antagonizes a bacterial DNA damage checkpoint
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DOI：
10.1111/mmi.14151
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发表时间：
2019-01-01
影响因子：
3.6
通讯作者：
Simmons, Lyle A.
中科院分区：
文献类型：
--
作者：
Burby, Peter E.;Simmons, Zackary W.;Simmons, Lyle A.
细菌协调DNA复制和细胞分裂，确保一套完整的遗传物质传递给下一代。当细菌遇到DNA损伤时，细胞周期检查点通过表达细胞分裂抑制剂而被激活。流行的模型是DNA损伤反应的激活和蛋白酶介导的抑制剂降解足以调节检查点过程。我们最近的全基因组筛选确定了基因ddcA作为暴露于DNA损伤的生存关键。与检查点恢复蛋白酶类似，由ddcA缺失引起的DNA损伤敏感性取决于检查点强制蛋白YneA。使用几种遗传方法，我们表明，DdcA功能是不同的检查点恢复过程。ddcA的缺失导致对YneA过表达的敏感性，而不依赖于YneA蛋白水平和稳定性，进一步支持DdcA调节YneA而不依赖于蛋白水解的结论。使用功能性GFP-YneA融合，我们发现DdcA阻止YneA依赖性细胞伸长，而不依赖于YneA定位。总之，我们的研究结果表明，DdcA通过帮助设置建立细胞周期检查点所需的YneA阈值来发挥作用，揭示了控制枯草芽孢杆菌中DNA损伤检查点激活的新调控步骤。
Bacteria coordinate DNA replication and cell division, ensuring a complete set of genetic material is passed onto the next generation. When bacteria encounter DNA damage, a cell cycle checkpoint is activated by expressing a cell division inhibitor. The prevailing model is that activation of the DNA damage response and protease-mediated degradation of the inhibitor is sufficient to regulate the checkpoint process. Our recent genome-wide screens identified the gene ddcA as critical for surviving exposure to DNA damage. Similar to the checkpoint recovery proteases, the DNA damage sensitivity resulting from ddcA deletion depends on the checkpoint enforcement protein YneA. Using several genetic approaches, we show that DdcA function is distinct from the checkpoint recovery process. Deletion of ddcA resulted in sensitivity to yneA overexpression independent of YneA protein levels and stability, further supporting the conclusion that DdcA regulates YneA independent of proteolysis. Using a functional GFP-YneA fusion we found that DdcA prevents YneA-dependent cell elongation independent of YneA localization. Together, our results suggest that DdcA acts by helping to set a threshold of YneA required to establish the cell cycle checkpoint, uncovering a new regulatory step controlling activation of the DNA damage checkpoint in Bacillus subtilis.