Bacterial osmoadaptation: coordination of osmoregulatory systems and their roles in cell growth

细菌渗透适应：渗透调节系统的协调及其在细胞生长中的作用

• 批准号: 508-2008
• 负责人: Wood, Janet
• 金额: $ 5.43万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=568125
• 关键词: Bacterial; osmoadaptation; coordination; osmoregulatory; systems

Osmotic pressure changes cause water to flow across the membranes that encase living cells. Such water fluxes can perturb cell structures and functions. Cells respond by adjusting their content of substances called organic osmolytes (amino acids, sugars etc). This "osmoregulation" controls water flow to ensure that cells remain properly hydrated, to stabilize their internal machinery, and to support their continuing growth. The osmoregulatory machinery that modulates bacterial osmolyte content has been described. Now we aim to learn how the osmoregulatory systems of bacterium Escherichia coli are coordinated. We will test the following hypotheses. First, the ProQ protein is an RNA chaperone that regulates the genes encoding osmoregulatory proteins, including ProP and ProU. Second, ProP clusters with other membrane-based osmoregulatory proteins at the ends of E. coli cells, which are rod-shaped. This protein clustering, resulting from specific interactions among cell membrane and "cell skeleton" components, is necessary for effective osmoregulation and cell growth. This research is designed to address fundamental biological questions. In addition to elucidating osmoregulatory mechanisms it may show us how bacterial cell structures form and function. It is teaching us how to fully translate genomes, predicting the structures and functions of the encoded RNAs and proteins. It may show us how small RNAs control gene expression. Some E. coli strains promote the health of their human and animal hosts. Other strains cause diseases when they infect intestines, brains, bladders or kidneys. Although our work is not designed to directly address food or water safety problems, or control disease, it will show how osmoregulatory mechanisms help E. coli to survive in food, water and animals, including people. Our discoveries will also apply to cells of other microbes, animals and plants that must tolerate osmotic pressure changes. They include yeasts (used to make bread, beer and wine), plant root and leaf cells (which tolerate drought and saline soils) and kidney cells (which control the hydration of people and animals).

渗透压的变化导致水流过包裹活细胞的细胞膜。这样的水通量会扰乱细胞的结构和功能。细胞通过调整有机渗透物（氨基酸、糖等）的含量来做出反应。这种“渗透调节”控制水流，以确保细胞保持适当的水分，稳定其内部机制，并支持其持续生长。已经描述了调节细菌渗透物含量的渗透调节机制。现在我们的目标是了解大肠杆菌的渗透调节系统是如何协调的。我们将检验以下假设。首先，ProQ蛋白是一种RNA伴侣蛋白，它调节编码渗透调节蛋白的基因，包括ProP和ProU。其次，ProP与其他膜基渗透调节蛋白聚集在大肠杆菌细胞的末端，呈棒状。这种由细胞膜和“细胞骨架”组分之间的特定相互作用引起的蛋白质聚集是有效渗透调节和细胞生长所必需的。