Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo.
Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo.
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DOI：
10.3390/ijms18071340
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发表时间：
2017-06-22
影响因子：
5.6
通讯作者：
She Q
中科院分区：
文献类型：
--
作者：
Han W;Feng X;She Q
反向旋转酶将正超螺旋引入环状 DNA，并参与嗜热菌基因组稳定性的维持。极端嗜热的crenarchaeon Sulfolobus编码两种反向旋转酶蛋白，TopR1（拓扑异构酶反向旋转酶1）和TopR2，其在嗜热生命中的功能仍有待证明。在这里，我们研究了 TopR1 在 S. islandicus 基因组稳定性维持中的作用，以响应 DNA 烷基化剂甲磺酸甲酯 (MMS) 的处理。致命的 MMS 治疗诱导了两个连续事件：大量染色体 DNA 主链断裂和随后的 DNA 降解。前者发生在药物治疗后立即发生，导致染色体 DNA 降解，与 TopR1 降解同时发生，随后是染色质蛋白降解和无 DNA 细胞形成。为了进一步了解 TopR1 功能，使用 CRISPR 介导的 mRNA 干扰方法 (CRISPRi) 降低了 S. islandicus 细胞中该酶的表达，其中 topR1 mRNA 被内源性 III-B CRISPR-Cas 系统靶向降解。我们发现，S. islandicus CRISPRi 细胞中的 TopR1 水平降低，并且细胞在 MMS 处理期间经历了加速的基因组 DNA 降解，并伴随着更高的细胞死亡率。总而言之，这些结果表明 TopR1 可能通过保护 DNA 断裂免受体内热降解来促进基因组完整性维护。
Reverse gyrase introduces positive supercoils to circular DNA and is implicated in genome stability maintenance in thermophiles. The extremely thermophilic crenarchaeon Sulfolobus encodes two reverse gyrase proteins, TopR1 (topoisomerase reverse gyrase 1) and TopR2, whose functions in thermophilic life remain to be demonstrated. Here, we investigated the roles of TopR1 in genome stability maintenance in S. islandicus in response to the treatment of methyl methanesulfonate (MMS), a DNA alkylation agent. Lethal MMS treatment induced two successive events: massive chromosomal DNA backbone breakage and subsequent DNA degradation. The former occurred immediately after drug treatment, leading to chromosomal DNA degradation that concurred with TopR1 degradation, followed by chromatin protein degradation and DNA-less cell formation. To gain a further insight into TopR1 function, the expression of the enzyme was reduced in S. islandicus cells using a CRISPR-mediated mRNA interference approach (CRISPRi) in which topR1 mRNAs were targeted for degradation by endogenous III-B CRISPR-Cas systems. We found that the TopR1 level was reduced in the S. islandicus CRISPRi cells and that the cells underwent accelerated genomic DNA degradation during MMS treatment, accompanied by a higher rate of cell death. Taken together, these results indicate that TopR1 probably facilitates genome integrity maintenance by protecting DNA breaks from thermo-degradation in vivo.
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影响因子：
8.8
作者：
Samson RY;Xu Y;Gadelha C;Stone TA;Faqiri JN;Li D;Qin N;Pu F;Liang YX;She Q;Bell SD
通讯作者：
Bell SD
影响因子：
9.2
作者：
Cejka, P;Mojas, N;Jiricny, J
通讯作者：
Jiricny, J
影响因子：
3.2
作者：
Frols, Sabrina;Gordon, Paul M. K.;Schleper, Christa
通讯作者：
Schleper, Christa
影响因子：
3.6
作者：
Guo, R;Xue, H;Huang, L
通讯作者：
Huang, L
影响因子：
14.9
作者：
Kampmann, M;Stock, D
通讯作者：
Stock, D