Roles of Checkpoint and DNA Repair Proteins in Fission Yeast Telomere Maintenance

检查点和 DNA 修复蛋白在裂殖酵母端粒维护中的作用

基本信息

批准号：
7894567
负责人：
Toru Nakamura
金额：
$ 26.07万
依托单位：
UNIVERSITY OF ILLINOIS AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-08-01 至 2011-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7894567
关键词：
Affect Apoptosis Biological Assay Biological Models Cell Cycle Cell Cycle Arrest Cell Cycle Progression Cells Chromatin Structure Chromosomes Complex DNA DNA Damage DNA Repair DNA Repair Enzymes DNA Structure DNA biosynthesis DNA damage checkpoint DNA repair protein Development Event Fission Yeast Future Generations Genetic Recombination Genome Genomic Instability Goals Hereditary Disease Histone H2A Homologous Gene Human Length Link Methods Modeling Mutation Other Genetics Phosphorylation Phosphotransferases Play Primer Extension Protein Binding Proteins Recruitment Activity Reporter Research Research Personnel Role Schizosaccharomyces pombe Proteins Shapes Southern Blotting Structure Telomerase Telomere Maintenance Telomere-Binding Proteins Testing Up-Regulation Work base insight mutant neoplastic cell prevent programs research study response sensor telomere tumor tumor growth tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): Proper maintenance of telomere structure is crucial for stable inheritance of the genome. Various checkpoint and DNA repair proteins, including evolutionarily highly conserved checkpoint kinases Tel1 (ATM) and Rad3 (ATR), play important roles in stable maintenance of telomeres. However, no clear mechanistic roles for various checkpoint and DNA repair proteins in telomere maintenance have been established. Major goal of our research is to understand how checkpoint and DNA repair proteins contribute to telomere maintenance. The current proposal will utilize fission yeast Schizosaccharomyces pombe as a model system. Highly conserved DNA damage responses and telomere maintenance mechanisms between fission yeast and humans should be helpful in extrapolating our findings to build testable models for human cells. Deregulation of telomere maintenance mechanisms has been found to be a key event in tumorigenesis, thus mechanistic insights on how various proteins collaborate to generate functional telomeres are first needed to devise effective methods for preventing tumorigenesis. In order to be stably maintained, telomeres must fulfill two major functions. First, telomeres must protect telomeric DNA ends from fusions and degradation. Second, telomeres must provide access to telomerase to prevent loss of telomeric DNA after DNA replication. Thus, telomeres must undergo dynamic switches from the highly protected state to the more accessible state that allows recruitment of telomerase. We hypothesize that checkpoint and DNA repair proteins are recruited to telomeres in a cell cycle-regulated manner to trigger appropriate changes in telomere structure and telomere protein composition. This model will be directly tested in Aim 1. Additionally, newly developed fission yeast reporter strains will be utilized to search for potential telomere targets of Rad3 and Tel1 kinases in Aim 2. Our preliminary studies with MRN (Mre11-Rad50-Nbs1) complex mutants have suggested that recruitment of Tel1 to telomeres does not require Tel1-MRN interaction unlike recruitment of Tel1 to other DNA breaks. Therefore, attempts will be made in Aim 3 to understand the mechanistic basis for the MRN-independent recruitment of Tel1 to telomeres.

描述（由申请人提供）：端粒结构的正确维护对于基因组的稳定遗传至关重要。各种检查点和 DNA 修复蛋白，包括进化上高度保守的检查点激酶 Tel1 (ATM) 和 Rad3 (ATR)，在端粒的稳定维持中发挥着重要作用。然而，各种检查点和 DNA 修复蛋白在端粒维持中的明确机制作用尚未确定。我们研究的主要目标是了解检查点和 DNA 修复蛋白如何促进端粒维持。目前的提案将利用裂殖酵母粟酒裂殖酵母作为模型系统。裂殖酵母和人类之间高度保守的 DNA 损伤反应和端粒维持机制应该有助于推断我们的发现，为人类细胞建立可测试的模型。人们发现端粒维持机制的失调是肿瘤发生的关键事件，因此首先需要了解各种蛋白质如何协作产生功能性端粒的机制，以设计预防肿瘤发生的有效方法。为了稳定维持，端粒必须履行两大功能。首先，端粒必须保护端粒 DNA 末端免于融合和降解。其次，端粒必须提供连接端粒酶的途径，以防止 DNA 复制后端粒 DNA 丢失。因此，端粒必须经历从高度保护状态到允许端粒酶募集的更容易接近的状态的动态转换。我们假设检查点和 DNA 修复蛋白以细胞周期调节的方式被招募到端粒，以触发端粒结构和端粒蛋白组成的适当变化。该模型将在目标 1 中直接进行测试。此外，新开发的裂殖酵母报告菌株将用于在目标 2 中寻找 Rad3 和 Tel1 激酶的潜在端粒靶点。我们对 MRN (Mre11-Rad50-Nbs1) 复合突变体的初步研究已经表明，与 Tel1 招募到其他 DNA 断裂不同，Tel1 招募到端粒不需要 Tel1-MRN 相互作用。因此，目标 3 将尝试了解 Tel1 独立于 MRN 招募到端粒的机制基础。