Autoinducer-2 signaling is involved in regulation of stress-related genes of Deinococcus radiodurans
Autoinducer-2 signaling is involved in regulation of stress-related genes of Deinococcus radiodurans
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Autoinducer-2 信号传导参与耐辐射奇球菌应激相关基因的调节
DOI：
10.1007/s00203-015-1163-7
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发表时间：
2016-01-01
影响因子：
2.8
通讯作者：
Tian, Bing
中科院分区：
文献类型：
--
作者：
Lin, Lin;Li, Tao;Tian, Bing
自诱导物2（Autoinducer-2，AI-2）是一种群体感应信号分子，介导细菌种内和种间的通讯，在调节细菌的各种行为中起着重要作用。本研究通过构建LuxS基因缺失突变株、存活表型分析和基因转录分析，研究了AI-2信号转导在极端嗜热菌Deinococcus radiodurans R1中的功能。与野生型菌株相比，不能产生AI-2的基因突变体（DRΔLuxS）对γ辐射和H2 O2都显著更敏感。在DRΔLuxS细胞培养液中加入野生型来源的培养液，可完全恢复DRΔLuxS的辐射抗性。耐辐射的与野生型相比，在正常或氧化胁迫下，突变体中积累了更高水平的活性氧。实时荧光定量PCR分析表明，DRΔLuxS胁迫相关蛋白（包括过氧化氢酶、胞外核酸酶、Dps-1和ABC转运蛋白）的转录水平均降低，表明AI-2参与了DRΔLuxS胁迫相关基因的调控。耐辐射的因此，AI-2信号可能有助于D.抗辐射和氧化应激。
Autoinducer-2 (AI-2) serves as a quorum-sensing signaling molecule that mediates both intraspecies and interspecies communication among bacteria, and plays critical roles in regulating various bacterial behaviors. In the present study, we investigated the functions of AI-2 signaling in the extremophilic bacterium Deinococcus radiodurans R1 by construction of the LuxS gene disruption mutant, survival phenotype assay and gene transcription assay. The gene mutant (DRΔLuxS), which was unable to produce AI-2, was significantly more sensitive to both gamma radiation and H2O2 compared with the wild-type strain. Addition of the wild-type-derived spent medium into the cell culture of DRΔLuxS fully restored the radioresistance of D. radiodurans. A higher level of reactive oxygen species accumulated in the mutant compared with the wild type under normal or oxidative stress. Quantitative real-time PCR assays showed that transcriptional levels of stress-related proteins, including catalase, extracellular nuclease, Dps-1 and ABC transporters, were decreased in DRΔLuxS, indicating that AI-2 is involved in regulation of stress-related genes of D. radiodurans. Hence, AI-2 signaling may contribute to the extreme resistance of D. radiodurans to radiation and oxidative stresses.