ATP-Dependent Chromatin Remodeling and Genomic Instability in Mammalian Cells

哺乳动物细胞中 ATP 依赖性染色质重塑和基因组不稳定性

基本信息

批准号：
8318991
负责人：
LEI LI
金额：
$ 25.82万
依托单位：
UNIVERSITY OF TX MD ANDERSON CAN CTR
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-08-01 至 2014-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8318991
关键词：
Actins Address Affect Alleles Amino Acid Motifs Apoptosis Apoptotic Biological Models Cell Cycle Arrest Cell Cycle Checkpoint Cell Cycle Regulation Cell Proliferation Cell model Cells Chromatin Chromatin Remodeling Factor Chromatin Structure Complex DNA DNA Damage DNA Double Strand Break DNA Repair DNA lesion Defect Detection Eukaryota Excision Genes Genetic Genetic Models Genetic Recombination Genetic Transcription Genome Stability Genomic Instability Genomics Goals Histones Human Human Genome Investigation Ionizing radiation Lead Lesion Maintenance Mammalian Cell Mammalian Genetics Molecular Molecular Genetics Mutagens Mutation Nuclear Nuclear Protein Null Lymphocytes Play Process Proteins Radiation Relaxation Role Saccharomycetales Signal Transduction System UV induced Work Yeast Model System base cancer therapy chromatin modification chromatin remodeling design loss of function member new therapeutic target novel protein complex repaired response tool

项目摘要

ABSTRACT The Ino80 chromatin remodeling complex plays an important role in the repair of radiation-induced DNA double strand breaks in lower eukaryotes. This discovery provides the first strong evidence that accessibility to DNA in the context of highly compact chromatin structure is a critical factor in DNA damage response. It becomes increasingly clear that maintenance of genome stability depends on highly coordinated actions of DNA damage repair, cell cycle checkpoint, and chromatin remodeling mechanisms. While the first two mechanisms have been the subject of extensive investigations during the past decades, the role of chromatin modification and remodeling in DNA damage response remains largely unclear, particularly in mammalian systems. Our proposed studies are aimed at delineating how chromatin remodeling activities support removal of DNA lesions and initiation of damage-induced cell cycle checkpoint signals. Our focus will be on two key subunits of the Ino80 ATP-dependent chromatin remodeling complex, Ino80 and Arp5. Ino80 is a unique member of the SNF2 superfamily that is believed to be a specialized chromatin remodeler assisting in DNA repair. Arp5 is an actin-related nuclear protein and an integral subunit of the Ino80 complex. Mutations of either gene in budding yeast render cells hypersensitive to a broad spectrum of genotoxic agents. In this application, we seek to understand how Ino80 modulates DNA damage responses. We have successfully created, via homologous targeting, loss-of-function human cellular models for INO80 and ARP5. These genetic model systems will serve as unique tools to study the function of Ino80 and Arp5 in cell proliferation, repair of ionizing radiation and UV-induced DNA lesions, damage-induced cell cycle arrest, and apoptosis. Our results are expected to further elucidate the mechanisms of the DNA damage response system and the molecular basis of genomic instability at large. Our results should also be useful for identification of novel therapeutic targets, especially targets for radiation sensitization. NARRATIVE Access to DNA lesions is a key prerequisite for many cellular mechanisms that act to protect the integrity of the human genome. Studies proposed in this application seek to understand the role of chromatin remodeling complex in creating such access by using molecular and genetics approaches. Results from the proposed work have the potential to unveil novel mechanism of genetic instability and to identify novel targets for cancer therapy.

抽象的 INO80染色质重塑络合物在修复中起着重要作用辐射诱导的DNA双链在下部真核生物中断裂。这个发现提供了第一个有力的证据，表明在高度背景下可访问DNA 紧凑型染色质结构是DNA损伤反应的关键因素。它变成了越来越清楚的是，基因组稳定性的维持取决于高度协调 DNA损伤修复，细胞周期检查点和染色质重塑的作用机制。虽然前两种机制一直是广泛的主题在过去几十年中的调查，染色质修饰和 DNA损伤反应中的重塑基本不清楚，尤其是在哺乳动物中系统。我们提出的研究旨在描述染色质的重塑活动支持去除DNA病变并启动损伤引起的细胞周期检查点信号。我们的重点将放在INO80 ATP依赖性的两个关键亚基上染色质重塑复合物，INO80和ARP5。 INO80是SNF2的独特成员超家族被认为是一种专门的染色质改造，可帮助DNA 维修。 ARP5是一种与肌动蛋白相关的核蛋白，也是INO80的积分亚基复杂的。发芽的酵母中任何一个基因的突变使细胞对A过敏遗传毒性剂的广泛谱。在此应用程序中，我们试图了解如何 INO80调节DNA损伤反应。我们已经成功创建了同源靶向，INO80和ARP5的功能丧失人类细胞模型。这些遗传模型系统将作为研究Ino80功能的独特工具和ARP5在细胞增殖中，修复电离辐射和紫外线诱导的DNA病变，损伤引起的细胞周期停滞和凋亡。我们的结果有望进一步阐明DNA损伤响应系统和分子的机制基因组不稳定性的基础。我们的结果也应用于识别新型的治疗靶标，尤其是辐射敏化的靶标。叙述进入DNA病变是许多作用于许多细胞机制的关键先决条件保护人类基因组的完整性。该申请中提出的研究寻求了解染色质重塑复合物在创建此类访问中的作用分子和遗传学方法。拟议工作的结果有潜力揭示遗传不稳定性的新型机制，并确定癌症的新目标治疗。