Physiological role of RpoS-controlled functions of Escherichia coli

大肠杆菌 RpoS 控制功能的生理作用

• 批准号: 46644-2010
• 负责人: Schellhorn, Herb
• 金额: $ 2.91万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=521804
• 关键词: Physiological; role; RpoS; controlled; functions

Increasing our knowledge regarding bacterial genes that are expressed in response to nutrient deprivation or other stresses is crucial for understanding basic aspects of bacterial physiology and environmental adaptation. In recent years, much has been learned about a key conserved regulator, RpoS, that is required for the expression of a large number of stress-induced genes but many unanswered questions remain. We do not have a full understanding of the function of genes controlled by RpoS. To address this, we will use genetic and molecular biology tools to examine the expression of RpoS-dependent genes that we have isolated. By simultaneously characterizing many RpoS-dependent genes, we will learn how these genes differ as a class from so-called housekeeping genes that are required for normal growth. In addition to characterizing RpoS-dependent genes, we will investigate specific questions that have arisen from our previous studies regarding lysine decarboxylase, transaldolase and catalase expression. Each of these stationary-specific genes are probably important in helping the cell adapt to stress conditions since we have found that they are expressed only in stationary phase when cells are in a starved state--they are not expressed under normal conditions. We will also examine how selected mutations in RpoS contribute to the overall fitness of the bacterial cell and will use metabolite analysis to discover how RpoS affects metabolite flux in bacteria maintained under suboptimal growth conditions. These studies will extend our knowledge of factors that contribute to bacterial persistence and survival.

增加我们对细菌基因的了解，这些基因是在营养缺乏或其他压力下表达的，这对于理解细菌生理学和环境适应的基本方面至关重要。近年来，人们对一个关键的保守调节因子RpoS有了很大的了解，RpoS是大量胁迫诱导基因表达所必需的，但仍存在许多未解之谜。我们对RpoS控制的基因的功能还没有完全的了解。为了解决这个问题，我们将使用遗传和分子生物学工具来检查我们分离的Rpos依赖基因的表达。通过同时表征许多Rpos依赖基因，我们将了解这些基因与正常生长所需的所谓管家基因的区别。除了表征RPOS依赖的基因，我们将调查的具体问题，我们以前的研究赖氨酸脱羧酶，transaldolase和过氧化氢酶的表达。这些静止特异性基因中的每一个可能在帮助细胞适应应激条件方面都很重要，因为我们发现它们只在细胞处于饥饿状态时的静止期表达-它们在正常条件下不表达。我们还将研究RpoS中的选定突变如何有助于细菌细胞的整体适应性，并将使用代谢物分析来发现RpoS如何影响在次优生长条件下维持的细菌中的代谢物通量。 这些研究将扩展我们对细菌持久性和存活因素的认识。