耐辐射异常球菌非编码RNA drrA参与UV氧化胁迫反应的调控机制

Bacterial small non-coding RNAs (sRNAs) as post-transcriptional regulators play essential roles in responsive mechanisms to environmental stresses. The bacterium Deinococcus radiodurans is one of the most radioresistant organisms known. The mechanisms of high effiecient DNA repair and oxidation resistance in this bacterium have attracted extensive research interests; however, sRNA-related study is still very limited, especially on their biological functions and mechanisms. In our previous study we comprehensively analyzed the high-quality transcriptome acomppanied with RT-PCR and Northern blot results, and discovered an sRNA, drrA, likely to be involved in the responsive mechanisms of oxidation and UV radiation resistance in D. radiodurans. We herein propose to study the biological function of this sRNA by constructing the drrA-mutant strain, identify its target through expression profile analysis and protein-nucleotide interaction technique, and investigate the mechanisms of drrA regulating the UV and oxidative stress response of D. radiodurans by qRT-PCR, biomolecular interaction analysis, etc. The results will fundamentally improve the understanding of how the radioresistant microbes manage the radio-oxidative stress.

细菌非编码RNA（sRNAs）作为转录后调控因子在各种胁迫反应过程中发挥着重要调控作用。耐辐射异常球菌是地球上最耐辐射的生物之一，其高效DNA损伤修复、氧保护机制成为研究的焦点。然而，耐辐射微生物中涉及到非编码sRNAs的研究极少，特别是在sRNAs生物学功能及作用机制研究上未见报道。前期研究中，通过D. radiodurans氧化胁迫下的全转录组学深度测序分析、 RT-PCR和Northern blot分析确实了一个非编码sRNA drrA，可能参与UV辐射氧化胁迫抗性反应的调节。本研究拟通过构建drrA突变株，开展其功能鉴定、利用转录谱分析及蛋白-靶基因互作等技术，明确其靶标，qRT-PCR、生物分子互作分析等探索drrA在D. radiodurans辐射氧化胁迫反应中的调控机制，研究结果将为深入了解耐辐射微生物的辐射氧化抗性机制奠定重要的理论基础。

细菌非编码RNA（sRNAs）作为转录后调控因子在各种胁迫反应程中发挥着重要调控作用。耐辐射异常球菌是地球上最耐辐射和氧化胁迫抗性的生物之一，已预测其含有一百多个非编码RNAs，但有关sRNAs的功能以及在DNA损伤修复、氧保护中的作用报道甚少。本项目研究发现和鉴定了一个氧化胁迫诱导的依赖于转录因子Sig1表达的sRNA OsiR （Oxidative Stress Induced RNA），通过构建OsiR突变株，采用qRT-PCR、转录学、蛋白组学及生物分子互作分析等手段，进行其功能鉴定、明确了3个OsiR靶标基因（tRNA修饰酶/GTP水解酶基因trmE、过氧化氢酶基因katE2和黄嘌呤脱氢酶铁硫亚基基因xdhA），OsiR通过与靶基因mRNA结合，增强mRNA稳定性，提高了耐辐射异常球菌的氧化胁迫抗性。研究结果揭示了sRNA参与耐辐射微生物氧化胁迫反应的调控机制，为深入了解耐辐射微生物的辐射氧化抗性机制奠定重要的理论基础。