Post-transcriptional regulation of RpoS synthesis

RpoS 合成的转录后调控

• 批准号: 6572041
• 负责人: THOMAS A. ELLIOTT
• 金额: $ 22.48万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6572041
• 关键词: Escherichia coli; RNA binding protein; antisense nucleic acid; bacterial RNA; bacterial proteins; cell cycle; gene mutation; genetic regulation; microorganism growth; microorganism metabolism; molecular genetics; nucleic acid structure; posttranscriptional RNA processing; protein biosynthesis; site directed mutagenesis; transcription factor

DESCRIPTION (provided by applicant): RpoS is a sigma factor, discovered and best studied in the enteric bacteria, that is important in orchestrating responses to many stresses. RpoS activity is greatly increased during stationary phase after growth in rich medium, by limitation for individual nutrients (e.g. carbon or nitrogen), by high osmolarity medium, and after entry into the eukaryotic host cell, among other stimuli. Expression of more than 50 genes responds to RpoS, and the cognate gene products act to mitigate the adverse consequences of stress for the cell. RpoS matters in the real world, where "feast and famine" is the norm. Our goal is to understand the mechanisms regulating RpoS abundance, which are poorly understood. The principal control occurs by post-transcriptional regulation of RpoS synthesis, and by regulated protein turnover. We focus here on the control of RpoS synthesis. Escherichia coil is our model organism, but the results should be broadly applicable, in two senses. First, they should illuminate the important role of RpoS in pathogenic genera such as Salmonella and Yersinia, and they will also advance our understanding of post-transcriptional gene regulation.Genetic analysis has suggested that one known RNA-binding protein, Hfq, and another possible RNA binding protein, DksA, are likely to interact with rpoS mRNA to control its expression. The small molecule "alarmone" ppGpp also has a role. The target mRNA has an antisense element that pairs with the ribosome binding site to limit translation. The function of the antisense element is counteracted in a way that requires the RNA-binding proteins and under at least some conditions, a trans-acting anti-antisense RNA. Experiments described in the specific aims utilize mainly genetic but also physical approaches: to verify the secondary structure of the rpoS mRNA, to identify the important proximal factors and their sites of action, and to determine exactly what happens to this mRNA to increase its expression.

描述（由申请人提供）：RPOS是肠道细菌中发现和最佳研究的Sigma因子，这对于策划对许多压力的反应很重要。在富培养基中，通过限制单个营养物质（例如碳或氮），高渗透压培养基以及进入真核宿主细胞以及其他刺激以及其他刺激之后，RPOS活性大大增加了富培养基（例如碳或氮）的局限性（例如碳或氮），大大增加了。超过50个基因的表达对RPO响应，而同源基因产物可缓解细胞应力的不利后果。 RPO在现实世界中很重要，在现实世界中，“盛宴和饥荒”是常态。 我们的目标是了解调节RPOS丰度的机制，这些机制知之甚少。主要控制是通过RPOS合成后的转录后调节和调节的蛋白质更新。我们将重点放在RPOS合成的控制上。大乙烯线圈是我们的模型生物，但结果应在两种感觉上广泛适用。首先，他们应该阐明RPO在病原属中的重要作用，例如沙门氏菌和耶尔森氏菌，它们还将提高我们对转录后基因调控的理解。基因分析表明，一种已知的RNA结合蛋白HFQ，HFQ和另一种可能的RNA可能的RNA结合蛋白DKSA，DKSA，DKSA，DKSA，可能与RPOS MRNA相互作用。小分子“ Alarmone” PPGPP也有角色。靶mRNA具有反义元件，该元件与核糖体结合位点配对以限制翻译。反义元件的功能以一种需要RNA结合蛋白的方式来抵消，并且至少在某些条件下，是反式抗抗抗抗反感RNA。特定目的中描述的实验主要利用遗传学，但也采用了物理方法：验证RPOS mRNA的二级结构，以确定重要的近端因子及其作用位点，并确定这种mRNA的确切表达情况以增加其表达。