Novel mechanisms of posttranscriptional regulation by CsrA

摘要(30行文本) 全球调节蛋白作用于它们的rna靶标的机制是复杂的，而且仍然是 很大程度上还不清楚；了解这些机制对于预防或减轻细菌 感染。作为细菌中已建立的主要全球转录后调控因子之一，CSRA RNA- 结合蛋白隐藏了有效的应激诱导转录后调控的丰富策略，这些策略是 不是很清楚。这项拟议工作的首要目标是在体内表征分子 作为我们最近发现的新型CSRA-目标相互作用的基础以及解密的特征 这些相互作用的生物学相关性。CSRA蛋白是CSR(碳储存调节因子)的一部分 系统，一个已知的影响毒力因子、分泌系统和其他方面的全球监管网络 在许多病原体中，重要的基因是快速适应宿主的。根据我们最近的发现，我们 提出新的假设：(I)CSRA在其靶点上具有不同类型的结合位点，(Ii)CSRA可以 单个靶点内的多个结合位点组合可能导致不同的调控结果，(Iii) CSRA与广泛的细胞sRNA相互作用并有助于调节，并且(Iv) CSRA调控的非典型特征在大肠杆菌之外是保守的。我们的总体目标是测试这些 在大肠杆菌CSRA目标组和同源RSMA目标组在P. 铜绿假单胞菌。根据我们的总体目标，我们提出了三个具体目标：(1)在体内表征 CSRA靶点的调节结合位点，(2)体内CSRA-SRNA相互作用及其相互作用的研究 功能相关性，以及(3)表征铜绿假单胞菌中RSMA靶标的结合和调控。我们 期望这些研究将扩展我们目前转录后调控方法的范例， 全球监管机构对细菌施加压力。我们还期待这项基础性工作将继续提供 研究CSRA调节和其他全球RNA结合调节蛋白的框架，以告知其 作为治疗靶点的潜在用途。这项工作的一个极具创新性的方面是使用新的细胞内 我们实验室开发的探测工具。

Abstract (30 lines of text) The mechanisms by which global regulatory proteins operate on their RNA targets are complex and are still largely not understood; understanding these mechanisms is crucial for preventing or alleviating bacterial infections. As one of the major established global post-transcriptional regulator in bacteria, the CsrA RNA- binding protein hides a wealth of strategies for efficient stress-induced posttranscriptional regulation that are not well understood. The overarching goal of the proposed work is to characterize in vivo the molecular features that underlie novel CsrA-target interactions that we have recently uncovered as well as to decipher the biological relevance of these interactions. The CsrA protein is part of the Csr (carbon storage regulator) system, a global regulatory network known to impact virulence factors, secretion systems, and other important genes for rapid host adaptation in a number of pathogens. Based on our recent discoveries, we propose the new hypotheses that: (i) CsrA has diverse types of binding sites on its targets, (ii) CsrA can have multiple binding site combinations within a single target that can lead to different regulatory outcomes, (iii) CsrA interacts with and contributes to the regulation of a wide range of cellular sRNAs, and that (iv) noncanonical features of CsrA regulation are conserved beyond E. coli. Our overall objective is to test these hypotheses in the context of the E. coli CsrA targetome and of the homologue RsmA targetome in P. aeruginosa. Based on our overall goal, we propose three Specific Aims: (1) to characterize in vivo the regulatory binding sites of the CsrA targetome, (2) to characterize in vivo CsrA-sRNA interactions and their functional relevance, and (3) to characterize RsmA-target binding and regulation in P. aeruginosa. We expect that these studies will expand our current paradigm of post-transcriptional regulation approaches that global regulators exert in bacteria. We also expect that this fundamental work will continue to provide framework for studies of CsrA regulation and of other global RNA-binding regulatory proteins to inform their potential use as therapeutic targets. A highly innovative aspect of this work is the use of new intracellular probing tools developed in our lab.