Discovery of a dual protease mechanism that promotes DNA damage checkpoint recovery.
Discovery of a dual protease mechanism that promotes DNA damage checkpoint recovery.
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DOI：
10.1371/journal.pgen.1007512
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发表时间：
2018-07
期刊：
影响因子：
4.5
通讯作者：
Simmons LA
中科院分区：
文献类型：
--
作者：
Burby PE;Simmons ZW;Schroeder JW;Simmons LA
DNA损伤反应是在整个生物学中发现的信号通路。在许多细菌中，DNA损伤检查点通过诱导小的膜结合抑制剂的表达来实施，该抑制剂延迟细胞分裂，提供时间来修复受损的染色体。细胞在感知到成功修复后如何促进检查点恢复尚不清楚。通过使用高通量，正向遗传筛选，我们确定了两个不相关的蛋白酶，YlbL和CtpA，促进枯草芽孢杆菌DNA损伤检查点恢复。两种蛋白酶的缺失导致检查点蛋白YneA的积累。我们表明，DNA损伤的敏感性和蛋白酶突变体中细胞伸长的增加取决于yneA。此外，蛋白酶突变体中YneA的表达足以抑制细胞增殖。最后，我们表明，这两种蛋白酶与YneA相互作用，两种蛋白酶之一，CtpA，直接在体外切割YneA。通过这些结果，我们报告了使用膜结合细胞分裂抑制剂的细菌中DNA损伤检查点恢复的机制。原核生物和真核生物使用DNA损伤检查点协调细胞分裂以实现基因组完整性。当DNA复制遇到障碍时，许多细菌表达一种小的膜结合蛋白来减缓细胞分裂。这类细胞分裂抑制剂已在几种细菌中被鉴定，但用于减轻抑制的机制仍然未知。使用正向遗传学，我们确定了两个未研究的基因，编码蛋白酶YlbL和CtpA，当删除时，会导致对直接损伤DNA的药物的敏感性。我们发现，蛋白酶突变体对DNA损伤的敏感性是细胞分裂抑制剂积累的结果。此外，我们表明，YlbL和CtpA负责降解细胞分裂抑制剂，允许细胞分裂恢复。重要的是，这两种蛋白酶不是同源物，这证明了细菌使用非同源酶降解单一底物的惊人例子。我们的研究揭示了以前未知的用于去除细胞分裂抑制剂的机制，同时也阐明了细菌可用于调节信号通路的潜在策略。使用多个不相关的蛋白质来执行单一功能可能代表了整个生物系统中采用的策略。
The DNA damage response is a signaling pathway found throughout biology. In many bacteria the DNA damage checkpoint is enforced by inducing expression of a small, membrane bound inhibitor that delays cell division providing time to repair damaged chromosomes. How cells promote checkpoint recovery after sensing successful repair is unknown. By using a high-throughput, forward genetic screen, we identified two unrelated proteases, YlbL and CtpA, that promote DNA damage checkpoint recovery in Bacillus subtilis. Deletion of both proteases leads to accumulation of the checkpoint protein YneA. We show that DNA damage sensitivity and increased cell elongation in protease mutants depends on yneA. Further, expression of YneA in protease mutants was sufficient to inhibit cell proliferation. Finally, we show that both proteases interact with YneA and that one of the two proteases, CtpA, directly cleaves YneA in vitro. With these results, we report the mechanism for DNA damage checkpoint recovery in bacteria that use membrane bound cell division inhibitors. Prokaryotes and eukaryotes coordinate cell division to genome integrity using DNA damage checkpoints. Many bacteria express a small, membrane binding protein to slow cell division when obstacles to DNA replication are encountered. Cell division inhibitors of this class have been identified in several bacterial species, yet the mechanism used to alleviate inhibition has remained unknown. Using forward genetics, we identified two unstudied genes, coding for the proteases YlbL and CtpA, that when deleted result in sensitivity to drugs that directly damage DNA. We show that sensitivity to DNA damage in protease mutants is a result of accumulation of the cell division inhibitor. Further, we show that YlbL and CtpA are responsible for degrading the cell division inhibitor allowing for cell division to resume. Importantly, these two proteases are not homologs, demonstrating a striking example of a bacterium using non-homologous enzymes to degrade a single substrate. Our investigation uncovers the previously unknown mechanism used to remove a cell division inhibitor, while also illuminating a potential strategy that bacteria can use to regulate signaling pathways. The use of multiple, unrelated proteins to perform a single function may represent a strategy employed throughout biological systems.
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影响因子：
4.5
作者：
Cárdenas PP;Carrasco B;Defeu Soufo C;César CE;Herr K;Kaufenstein M;Graumann PL;Alonso JC
通讯作者：
Alonso JC
影响因子：
3.2
作者：
Goranov, Alexi I.;Kuester-Schoeck, Elke;Grossman, Alan D.
通讯作者：
Grossman, Alan D.
影响因子：
3.2
作者：
ALONSO, JC;LUDER, G;TAILOR, RH
通讯作者：
TAILOR, RH
影响因子：
3.2
作者：
Karimova, G;Dautin, N;Ladant, D
通讯作者：
Ladant, D
DOI：
10.1111/j.2517-6161.1995.tb02031.x
发表时间：
1995-01-01
影响因子：
5.8
作者：
BENJAMINI, Y;HOCHBERG, Y
通讯作者：
HOCHBERG, Y