Novel regulatory mechanisms controlling DnaA and the timing of DNA replication during the Caulobacter crescentus cell cycle

新月柄杆菌细胞周期中控制 DnaA 和 DNA 复制时间的新调控机制

• 批准号: 183356334
• 负责人: Dr. Kristina Jonas
• 金额: --
• 依托单位: Department of Biology
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/183356334?language=en
• 关键词: Novel; regulatory; mechanisms; controlling; DnaA

All cells must ensure the correct timing of DNA replication and its coordination with cell cycle events. In the model bacterium Caulobacter crescentus, DNA replication is controlled by the opposing activities of the cell cycle master regulator CtrA and the replication initiation protein DnaA, both of which oscillate over cell cycle progression, but out of phase with one another. Despite a detailed understanding about the temporal regulation of CtrA, the mechanisms that account for the oscillations of DnaA activity remain unclear. The regulation of DnaA was proposed to depend mainly on the fluctuating levels of DnaA. However, several findings strongly indicate the existence of additional mechanisms that control DnaA activity. The proposed study aims to understand these mechanisms and to study how they are coordinated with the Caulobacter cell cycle. My proposal describes a genetic screen for novel regulators of DnaA as well as a yeast two-hybrid screen to identify factors that interact physically with DnaA. By using a combination of genetic, biochemical, and cell biological assays the newly identified regulators will be characterized to determine how they modulate DnaA and DNA replication and to elucidate their connection with the known CtrA regulatory circuit. In addition to developing a better understanding of cell cycle control in Caulobacter, this work will provide insight into the general design principles of molecular based circuits.

所有细胞都必须确保 DNA 复制的正确时机及其与细胞周期事件的协调。在模型细菌 Caulobacter crescentus 中，DNA 复制受到细胞周期主调节因子 CtrA 和复制起始蛋白 DnaA 的相反活性控制，两者在细胞周期进程中振荡，但彼此不同相。尽管对 CtrA 的时间调节有了详细的了解，但导致 DnaA 活性振荡的机制仍不清楚。提出 DnaA 的调节主要取决于 DnaA 水平的波动。然而，一些研究结果强烈表明存在控制 DnaA 活性的其他机制。拟议的研究旨在了解这些机制并研究它们如何与柄杆菌细胞周期协调。我的提案描述了新型 DnaA 调节因子的遗传筛选以及酵母双杂交筛选，以确定与 DnaA 物理相互作用的因素。通过结合遗传、生化和细胞生物学检测，将对新鉴定的调节因子进行表征，以确定它们如何调节 DnaA 和 DNA 复制，并阐明它们与已知的 CtrA 调节回路的联系。除了更好地理解柄杆菌的细胞周期控制之外，这项工作还将深入了解基于分子的电路的一般设计原理。