CELL CYCLE REGULATION OF EUKARYOTIC DNA REPLICATION

真核 DNA 复制的细胞周期调控

• 批准号: 7155955
• 负责人: JOACHIM J LI
• 金额: $ 9.59万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7155955
• 关键词: DNA replication; DNA replication origin; Saccharomyces cerevisiae; cell cycle; cyclin dependent kinase; protein protein interaction

DESCRIPTION: The investigator's long-term goal is to understand how DNA replication is regulated during the eukaryotic cell cycle. A central question about this regulation is how replication origins are prevented from re-initiating DNA replication within a single cell cycle. Strict enforcement of this block at the hundreds to thousands of origins in an eukaryotic genome is required for the faithful propagation and stable transmission of genetic information. Loss of this control could contribute to the genomic instability associated with tumorigenesis. The investigator is studying the block to re-initiation in the budding yeast Saccharomyces cerevisiae, where combined genetic and biochemical analysts have identified many of the molecular components involved in regulating the cell cycle and initiating DNA replication. Work from their lab and that of others has shown that cyclin dependent kinases (CDKs; particularly Clb/Cdc28 in budding yeast) play a pivotal role in preventing re-initiation. In this proposal, he wishes to identify the critical targets of these kinases and determine how phosphorylation of these targets inhibits re-initiation. The investigator's preliminary studies raise the possibility that Clb kinases use multiple overlapping mechanisms to target three components of the initiation complex: the origin recognition complex (ORC); Cdc6; and the Mcm2-7 family of proteins. To test this hypothesis he will: (1) Determine whether simultaneous deregulation of these three initiation components leads to re-initiation of DNA replication; (2) Determine whether ORC and Mcm proteins are substrates of Clb kinases in vivo ; (3) Investigate the molecular mechanisms underlying the block to re-initiation; and (4) Test additional mechanisms that may contribute to the block to re-initiation. Because the components of the initiation machinery are conserved among eukaryotes, he anticipates that an understanding of how this machinery is regulated during the budding yeast cell cycle will serve as a paradigm for understanding this regulation in other eukaryotes.

描述：研究人员的长期目标是了解 DNA 是如何 复制在真核细胞周期中受到调节。一个中心问题 关于这个规则的问题是如何防止复制起点 在单个细胞周期内重新启动 DNA 复制。严格执行 真核基因组中成百上千个起源的这个块是 遗传的忠实繁殖和稳定传递所必需的 信息。失去这种控制可能会导致基因组不稳定 与肿瘤发生有关。调查员正在研究该区块 在芽殖酵母酿酒酵母中重新启动，其中组合 遗传和生化分析人员已经鉴定出许多分子 参与调节细胞周期和启动 DNA 的成分 复制。他们和其他实验室的工作表明，细胞周期蛋白 依赖性激酶（CDK；特别是芽殖酵母中的 Clb/Cdc28）发挥着重要作用 在防止重新启动方面发挥着关键作用。在这份提案中，他希望 确定这些激酶的关键靶点并确定如何 这些靶标的磷酸化会抑制重新启动。调查员的 初步研究提出了 Clb 激酶使用多种 针对起始复合物的三个组成部分的重叠机制： 起源识别复合体（ORC）； CDC6；和Mcm2-7 蛋白质家族。 为了检验这个假设，他将：（1）确定是否同时 这三种起始成分的失调会导致 DNA 的重新起始 复制； (2)确定ORC和Mcm蛋白是否是Clb的底物 体内激酶； (3) 研究阻断的分子机制 重新启动； (4) 测试可能有助于 阻止重新启动。因为引发机械的部件是 在真核生物中保守，他预计了解这种现象是如何发生的 机器在芽殖酵母细胞周期中受到调节，将作为 理解其他真核生物中这种调节的范例。