OSMOREGULATION IN STAPHYLOCOCCUS AUREUS

这项建议的广泛长期目标是提供一个 金黄色葡萄球菌渗透调节的综合描述。 希望这些知识对GRAM有广泛的应用 阳性细菌。金黄色葡萄球菌是一种极耐盐的真细菌 能够在含有超过3M氯化钠的介质中生长。这个 允许这种非凡的渗透耐受性的生理机制是 人们对此知之甚少。此外，众所周知，随着氯化钠的生长会对 金黄色葡萄球菌的细胞生理学。金黄色葡萄球菌是食物的主要来源 中毒和一种非常通用的各种器官的病原体和 纸巾。在高渗透压环境中生长的能力可能是一种 生物体致病性的重要属性。这个 渗透调节的生理学和生物化学将通过 确定分子的同一性和细胞内浓度 (渗透分子)在高渗透压介质中生长过程中积累的。这个 渗透调节的动力学将在细胞 易受高渗胁迫的渗透性物质的运输系统将 根据它们的动力学、底物特异性和 全细胞和膜泡对渗透胁迫的反应 准备工作。基因研究将涉及创造各种不同的 化学诱变和转座子诱变的渗透体突变体。渗透沸石 运输或代谢突变体将被选为无法生长的突变体 在含有2M氯化钠和渗透分子的限定介质上(例如，脯氨酸， 甘氨酸甜菜碱、胆碱)。外源非渗透压非依赖性突变体，以及 还将产生抗脯氨酸类似物运输突变体。 转座子lacZ融合突变体将被用来研究转录 渗透压调节基因的调控。转座子插入突变体将 用于克隆与渗透调节有关的基因。

The broad long-term objective of this proposal is to provide a comprehensive description of osmoregulation in Staphylococcus aureus. It is hoped that this knowledge will have wide application to gram positive bacteria. S. aureus is an extremely halotolerant eubacterium capable of growing in media containing in excess of 3 M NaCl. The physiological mechanisms allowing this remarkable osmotolerance are poorly understood. Also, growth with NaCl is known to profoundly affect the cell physiology of S. aureus. S. aureus is a major cause of food poisoning and an extremely versatile pathogen of a variety of organs and tissues. Ability to grow in high osmolarity environments might be an important attribute of the pathogenicity of the organism. The physiology and biochemistry of osmoregulation will be studied by determining the identity and intracellular concentration of molecules (osmolytes) accumulating during growth in high osmolarity media. The dynamics of osmoregulation will be probed in experiments where cells are subjected to hyperosmotic stress. Transport systems for osmolytes will be studied in terms of their kinetics, substrate specificity and response to osmotic stress in whole cells and membrane vesicle preparations. Genetic studies will involve the creation of various osmolyte mutants by chemical and transposon mutagenesis. Osmolyte transport or metabolism mutants will be selected for inability to grow on defined medium containing 2 M NaCl plus an osmolyte (e.g., proline, glycine betaine, choline). Exogenous osmolyte-independent mutants, and proline analog-resistant transport mutants will also be created. Transposon lacZ fusion mutants will be used to study the transcriptional regulation of osmoregulatory genes. Transposon insertion mutants will be used to clone genes involved in osmoregulation.