转录因子FboR调控耻垢分枝杆菌抗氧化生长的机制研究

Study on the Mechanism of Transcription Factor FboR Regulating Bacterial Antioxidant Growth in Mycobacterium smegmatis

结核病的致病菌结核分枝杆菌(Mycobacterium tuberculosis)在宿主内面临着多种氧化胁迫环境因子的压力,因而进化形成了一系列自己的抗氧化生长机制。转录因子作为细菌快速响应外界环境的重要因子,通过调控其靶基因的表达来帮助细菌适应环境胁迫如抗氧化等。然而,目前分枝杆菌(Mycobacterium)中有关转录因子调控细菌抗氧化生长的分子机制还不是十分清楚。本研究以耻垢分枝杆菌(Mycobacterium smegmatis)作为模式菌株,发现了转录因子FboR调控分枝杆菌的抗氧化能力并检测了相关重组菌株的抗氧化生长情况,证实了FboR负调控细菌的抗氧化能力。随后通过转录组测序分析、凝胶阻滞实验(electrophoretic mobility shift assay,EMSA)、实时定量PCR(real-time quantitative PCR,RT-qPCR)和β-半乳糖苷酶活性检测鉴定了影响细菌抗氧化生长的相关靶基因,成功解析了具体的调控通路与分子机制。

Mycobacterium tuberculosis,the causative bacterium of tuberculosis,faces a variety of oxidative stress from environment in the infected host cells,so it has evolved a series of its own antioxidant growth mechanisms.As important factors for bacteria to respond quickly to the external environment,transcription factors help bacteria adapt to environmental stress including anti-oxidation by regulating the expression of their target genes.However,the molecular mechanism of transcription factors in mycobacteria regulating bacterial antioxidant growth is still unclear.In this study,Mycobacterium smegmatis was used as the model strain.The transcription factor FboR was found to regulate the antioxidant capacity of mycobacteria and the antioxidant growth of related recombinant strains was detected.This study confirmed that the antioxidant capacity of bacteria negatively regulated by FboR.Then this study identified the related target genes affecting bacterial antioxidant growth by transcriptome sequencing analysis,electrophoretic mobility shift assay(EMSA),real-time quantitative PCR(RT-qPCR)andβ-galactosidase activity test,and analyzed the specific regulatory pathway and molecular mechanism.