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

• 批准号: 8466714
• 负责人: LEI LI
• 金额: $ 28.17万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8466714
• 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

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.

摘要 Ino80染色质重塑复合物在修复中起重要作用。 在低等真核生物中辐射诱导的DNA双链断裂。这一发现 提供了第一个强有力的证据，表明在高度复杂的环境中， 紧密的染色质结构是DNA损伤反应中的关键因素。变得 越来越清楚的是，基因组稳定性的维持依赖于高度协调的 DNA损伤修复、细胞周期检查点和染色质重塑的作用 机制等虽然前两种机制一直是广泛讨论的主题， 研究在过去的几十年中，染色质修饰的作用， DNA损伤反应的重塑在很大程度上仍不清楚，特别是在哺乳动物中， 系统.我们提出的研究旨在阐明染色质重塑是如何 活性支持去除DNA损伤和启动损伤诱导的细胞周期 检查点信号。我们的重点将是两个关键亚基的Ino80 ATP依赖性 染色质重塑复合物，Ino80和Arp5。Ino80是SNF2的独特成员 超家族，被认为是一个专门的染色质重塑协助DNA 修复. Arp5是肌动蛋白相关的核蛋白，是Ino80的一个整合亚基 复杂.芽殖酵母中任一基因的突变都使细胞对a 广泛的遗传毒性物质。在本申请中，我们试图理解如何 Ino80调节DNA损伤反应。我们成功地创造了，通过 INO 80和ARP 5的同源靶向、功能丧失的人细胞模型。 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、电离辐射和UV诱导的DNA损伤的修复中的作用， 损伤诱导的细胞周期停滞和凋亡。我们的研究结果有望进一步 阐明了DNA损伤反应系统的分子机制， 基因组不稳定性的基础我们的结果也应该是有用的识别 新的治疗靶点，特别是用于辐射敏化的靶点。叙事 进入DNA损伤是许多细胞机制的关键先决条件， 保护人类基因组的完整性。本申请中提出的研究试图 了解染色质重塑复合物在创建这种访问中的作用， 分子和遗传学方法。拟议工作的结果有可能 揭示遗传不稳定性的新机制并确定癌症的新靶点 疗法