A conserved small RNA in the RpoS regulon

RpoS 调节子中的保守小 RNA

• 批准号: 39952677
• 负责人: Professor Dr. Jörg Vogel
• 金额: --
• 依托单位: Institut für Molekulare Infektionsbiologie (IMIB)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/39952677?language=en
• 关键词: conserved; small; RNA; RpoS; regulon

The master regulator of the general stress response in E. coli, the σS (RpoS) subunit of RNA polymerase, is a prime example of the interconnection of alternative sigma factor regulons and the regulation by environmentally induced small noncoding RNAs (sRNAs). It has been well-established that the translation of rpoS mRNA is modulated by Hfq-dependent sRNAs under a variety of growth and stress conditions. However, whether σS also relays stress signals in the cell via the induction of regulatory sRNAs has been unknown. Following our previous discoveries of sRNA genes controlled by the alternative sigma factors, σE or σN, we have now identified SdsR, the first sRNA that might regulated by σS. SdsR is an Hfq-associated sRNA, exceptionally abundant in stationary phase, and seems to be subject to antisense regulation by the oppositely encoded SraC sRNA. A high degree of genomic conservation and its frequent recovery by previous shotgun sequencing identified SdsR as an enterobacterial “core” small RNA, yet its function has remained elusive. This project aims to achieve a thorough understanding of the in vivo targets and molecular mechanisms by which SdsR participates in σS-mediated stress responses and regulation in E. coli and Salmonella. We will use a variety of experimental approaches to determine biological conditions under which SdsR expression and gene regulation is relevant, with the goal of understanding SdsR functions in the large σS network. The effects of putative antisense control of SdsR by SraC will also be addressed, which could establish a new paradigm in the action of Hfq-dependent sRNAs. In addition, we will utilize the abundance of SdsR sRNA to establish a new approach for in vivo RNA structure probing by deep sequencing, and address whether this sRNA can indirectly act as a global by titrating the activity of the sRNA chaperon, Hfq. The study of the enterobacterial core sRNAs such as SdsR is particularly interesting as it might identify functions and regulatory principles that extend beyond individual bacterial species.

大肠杆菌一般应激反应的主要调控因子，RNA聚合酶的σS （RpoS）亚基，是环境诱导的小非编码RNA （sRNAs）调控和备选σ因子调控相互联系的一个主要例子。已经证实，在各种生长和胁迫条件下，rpoS mRNA的翻译受到hfq依赖性sRNAs的调节。然而，σS是否也通过诱导调节性srna在细胞中传递应激信号尚不清楚。在我们之前发现由σE或σN控制的sRNA基因之后，我们现在发现了SdsR，这是第一个可能受σS调节的sRNA。SdsR是一种与hfq相关的sRNA，在固定期异常丰富，似乎受相反编码的SraC sRNA的反义调控。高度的基因组保守性和先前的霰弹枪测序频繁恢复表明SdsR是肠细菌的“核心”小RNA，但其功能仍然难以捉摸。本项目旨在深入了解SdsR在大肠杆菌和沙门氏菌中参与σ s介导的应激反应和调控的体内靶点和分子机制。我们将使用多种实验方法来确定SdsR表达和基因调控相关的生物学条件，目的是了解SdsR在大σS网络中的功能。本文还将讨论src对SdsR的反义控制的影响，这可能为hfq依赖性sRNAs的作用建立一个新的范例。此外，我们将利用SdsR sRNA的丰度，建立一种通过深度测序探测体内RNA结构的新方法，并通过滴定sRNA伴侣子Hfq的活性来确定该sRNA是否可以间接作为全局RNA。对肠细菌核心srna（如SdsR）的研究特别有趣，因为它可能确定超出单个细菌物种的功能和调节原理。