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

渗透压的变化导致水流过包裹活细胞的膜。 这样的水通量可以扰乱细胞结构和功能。 细胞通过调整有机渗透物质（氨基酸、糖等）的含量来做出反应。 这种“水分调节”控制着水流，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压物质含量的细胞外调节机制。 现在，我们的目标是了解如何协调细菌大肠杆菌的代谢调节系统。 我们将检验以下假设。 首先，ProQ蛋白是一种RNA分子伴侣，可调节编码蛋白质的基因，包括ProP和ProU。 第二，ProP与其他膜基的蛋白质在E.大肠杆菌细胞，呈杆状。 这种蛋白质聚集是由细胞膜和“细胞骨架”成分之间的特异性相互作用引起的，是有效的细胞增殖调节和细胞生长所必需的。

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.