基于转录组分析大肠杆菌响应亚碲酸盐的机制

Transcriptome profiling of Escherichia coli responding to tellurite

摘要:

亚碲酸盐对绝大多数微生物有高毒性,可用作抗菌剂；但其具体毒性机制仍不清楚。【目的】理解亚碲酸盐的毒性机制，揭示亚碲酸盐处理导致的代谢变化。【方法】本研究通过比较转录组分析与挖掘差异转录基因，探讨了大肠杆菌响应亚碲酸盐胁迫的机制。【结果】Escherichia coli MG1655在10µg/mL亚碲酸盐处理1 h后，比较和分析了亚碲酸盐处理组与对照组的转录水平差异，发现细胞呈现一种明显的适应性变化，许多参与重要代谢途径的基因转录水平改变。其中，与核糖体代谢和鞭毛组装相关基因的转录水平发生显著变化，表明这两条途径很可能是亚碲酸盐作用的主要途径。与细胞能动性、金属离子代谢、细胞膜功能相关的基因的转录水平也发生了明显变化，可能是由于其参与了抵抗亚碲酸盐毒性的细胞代谢调节和损伤修复。【结论】本项工作有助于推动亚碲酸盐毒性机理的研究，促进亚碲酸盐的临床应用。

关键词:亚碲酸盐;比较转录组;差异转录基因;核糖体代谢;鞭毛组装

Abstract:

Tellurite as a strong antimicrobial agent is highly toxic to a variety of microorganisms, while its toxicity mechanism remains indistinct. [Objective] The main goal of this work is to uncover the global changes of cell metabolism under tellurite stress and reveal the toxicity mechanism of tellurite. [Methods] The transcriptomes of Escherichia coli MG1655 exposed to tellurite stress and under normal conditions were compared to reveal the differentially transcribed genes. [Results] After being treated with 10 µg/mL tellurite for 1 h, the cells exhibited an obvious adaptive response with many metabolic processes influenced. The transcription levels of the genes involved in ribosome metabolism and flagellar assembly changed significantly, implying the two pathways were affected by tellurite. The genes encoding the transcriptional factors and small RNAs and those functioning in the cell motility, metal ion metabolism, and membrane function also showed varied transcription levels, which might participate in the metabolism regulation and damage repair to resist the toxicity of tellurite. [Conclusion] This work can facilitate the study of the toxicity mechanism and promote the clinical application of tellurite.

Key words:tellurite;comparative transcriptome;differentially transcribed genes;ribosome metabolism;flagellar assembly