铜绿假单胞菌小RNA调控RpoS表达的机理研究

项目名称： 铜绿假单胞菌小RNA调控RpoS表达的机理研究

项目编号： No.31300124

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 生物科学

项目作者： 卢培

作者单位： 中国科学院武汉病毒研究所

项目金额： 23万元

中文摘要： 细菌RpoS调控压力耐受及毒力基因的转录，具有全局调控效应，因此胞内的RpoS在转录、翻译及蛋白稳定性水平上均受到严格调控，是细菌中最为复杂的调控机制之一。大肠杆菌主要通过小RNA改变rpoS mRNA 二级结构在翻译水平调控RpoS表达，但这些小RNA并不存在于铜绿假单胞菌中。铜绿假单胞菌rpoS mRNA的非编码区参与自身调控，且有报道小RNA伴侣蛋白Hfq影响RpoS蛋白水平，但并不改变rpoS mRNA水平，预示铜绿假单胞菌中存在小RNA在转录后水平调控RpoS表达。本项目拟通过构建铜绿假单胞菌中小RNA的过表达文库，筛选调控RpoS表达的小RNA，分析小RNA与rpoS mRNA互补位点，检测小RNA对RpoS表达的调控与Hfq、RNA降解酶等因子的关系，分析其中的调控分子机制，为系统阐述RpoS翻译水平调控机理及铜绿假单胞菌毒力调控奠定基础。

中文关键词： RpoS；小RNA；转录后调控；RgsA；Hfq

英文摘要： RpoS was originally identified in Escherichia coli as an alternative σ factor that activates gene expression in stationary phase when cells are experiencing nutrient starvation. RpoS is considered as a master stress response regulator important for adaptation to a variety of conditions including heat, osmotic and oxidative stress and plays as a global regulatory effecter. Due to its important role, regulation of RpoS expression occurs strictly at the levels of transcription, translation and protein stability, which is one of the most complex regulatory systems in bacteria. In E. coli, the translational control of RpoS largely depends upon the 5' untranslated region (UTR) of rpoS mRNA and small non-coding RNAs (sRNAs). However, these sRNAs are absent in Pseudomonas aeruginosa. Previous research has revealed that the 5' UTR of rpoS mRNA and the sRNA chaperone Hfq are involved in the regulation of RpoS translation in P. aeruginosa, suggesting that there is (are) novel sRNA(s) which has(ve) regulatory role on RpoS expression. In this project, we will first construct the sRNAs over-expression library and identify novel sRNAs which have the regulatory effect on RpoS expression at post-transcriptional level in P. aeruginosa. The complementary regions between sRNA and rpoS mRNA will then be investigated. And experiments

英文关键词： RpoS；small non-coding RNA；post-transcriptional regulation；RgsA；Hfq