DqsIR quorum sensing-mediated gene regulation of the extremophilic bacterium Deinococcus radiodurans in response to oxidative stress
DqsIR quorum sensing-mediated gene regulation of the extremophilic bacterium Deinococcus radiodurans in response to oxidative stress
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DqsIR 群体感应介导的嗜极菌耐辐射奇球菌响应氧化应激的基因调控
DOI：
10.1111/mmi.13331
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发表时间：
2016-05-01
影响因子：
3.6
通讯作者：
Hua, Yuejin
中科院分区：
文献类型：
--
作者：
Lin, Lin;Dai, Shang;Hua, Yuejin
在这里，我们表明AHLS可以被耐辐射球菌所利用，该菌属于独特的耐辐射球菌门，以其细胞对环境压力的抵抗力而闻名。在耐辐射葡萄球菌中发现了一种AHL介导的群体感应系统(DqsI/DqsR)。我们发现，在非胁迫条件下，AHL水平被群体猝灭酶屏蔽，而AHL水平在耐辐射葡萄球菌暴露于氧化胁迫时积累。基因表达的时程分析表明，当暴露于H_2O_2时，AHL合成酶(DqsI)立即被诱导，而群体猝灭酶的表达在暴露于H_2O_2约30分钟后开始增加。与野生型菌株相比，dqsI突变体(DMDqsI)和dqsR突变体(MDqsR)对氧化胁迫更敏感。外源性AHLS(5M)可完全恢复氧化应激下DMDqsI的存活分数。RNA-seq分析表明，参与应激反应、细胞清洗和DNA修复的一些基因已经改变了MDqsR的转录水平。DqsR作为群体感应的调节器，与AHL一起控制基因的表达。因此，DqsIR介导的群体感应介导的基因调控是耐辐射假单胞菌应对氧化应激的一种适应性策略，并且在极端嗜热球菌中是保守的。
Here, we show that AHLs can be employed by Deinococcus radiodurans, which belongs to the unique phylum Deinococcus-Thermus and is known for its cellular resistance to environmental stresses. An AHL-mediated quorum-sensing system (DqsI/DqsR) was identified in D. radiodurans. We found that under non-stress conditions, the AHL level was shielded by quorum quenching enzymes, whereas AHLs accumulated when D. radiodurans was exposed to oxidative stress. Upon exposure to H2O2, AHL synthetic enzymes (DqsI) were immediately induced, while the expression of quorum-quenching enzymes began to increase approximately 30 min after exposure to H2O2, as shown by time-course analyses of gene expression. Both dqsI mutant (DMDqsI) and dqsR mutant (MDqsR) were more sensitive to oxidative stress compared with the wild-type strain. Exogenous AHLs (5 M) could completely restore the survival fraction of DMDqsI under oxidative stress. RNA-seq analysis showed that a number of genes involved in stress-response, cellular cleansing, and DNA repair had altered transcriptional levels in MDqsR. The DqsR, acting as a regulator of quorum sensing, controls gene expression along with AHLs. Hence, the DqsIR-mediated quorum sensing that mediates gene regulation is an adaptive strategy for D. radiodurans in response to oxidative stresses and is conserved in the extremophilic Deinococcus bacteria.