Define redundant functions of H2AX and NBS1 in DNA repair

定义DNA修复中H2AX和NBS1的冗余功能

• 批准号: 10311996
• 负责人: Junjie Chen
• 金额: $ 35.87万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-25 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10311996
• 关键词: ATM activation; Address; Affect; Applications Grants; BRCA1 gene; Biological Process; Camptothecin; Cancer Patient; Cell Line; Cell Survival; Cell physiology; Cells; Complex; DNA; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Repair Pathway; DNA damage checkpoint; DNA lesion; DNA-dependent protein kinase; Data; Defect; Double Strand Break Repair; Ensure; Excision; Exhibits; Foundations; Gene Proteins; Genome; Genomic Instability; Goals; Human; Hypersensitivity; Impairment; Knock-out; Laboratories; Libraries; Maintenance; Mediating; Molecular; Mus; NBS1 gene; Pathway interactions; Phosphorylation; Play; Poison; Process; Proteins; Proteomics; Research Personnel; Role; S phase; Series; Signal Pathway; Signal Transduction; Site; Testing; Type I DNA Topoisomerases; Work; ataxia telangiectasia mutated protein; cancer prevention; cancer therapy; genome integrity; homologous recombination; in vivo; inhibitor; nuclease; p53-binding protein 1; precision oncology; protein function; recombinational repair; recruit; repaired; response; sensor; tumorigenesis; whole genome

Project Summary Deciphering the molecular mechanisms underlying genomic instability and tumorigenesis is the long-term goal of my laboratory. The broad objective, of this proposal, reflects our pursuit to gain a comprehensive understanding of the network involved in DNA repair and to determine how these proteins and pathways intersect, interact, communicate, coordinate, and collaborate for genome maintenance. The short-term goal is to perform detailed mechanistic studies of several DNA damage signaling and repair pathways, which will provide the foundation to achieve our long-term goal of exploiting DNA repair network for cancer therapy. This proposal will define two overlapping DNA damage-signaling pathways that together are essential for cell survival. We and other researchers have constructed an elaborate signaling pathway that acts downstream of H2AX and regulates the recruitment and accumulation of many DNA damage repair proteins at sites of DNA breaks. This H2AX-dependent pathway is composed of H2AX, MDC1, RNF8, and RNF168. However, repair defects observed in H2AX-, MDC1-, RNF8-, or RNF168-deficient cells or mice are mild, raising the possibility that there is an H2AX-independent mechanism involved in the recruitment of these downstream repair proteins. We propose that this H2AX-independent pathway is controlled by NBS1. On the basis of our previous studies and preliminary data presented in this proposal, we hypothesize that the H2AX- and NBS1-dependent pathways are involved in the DNA damage response and are critical for cell survival. We believe that these two pathways have redundant functions, especially in promoting homologous recombination repair. However, they are not completely separate, since they intersect at multiple points. This makes it considerably challenging for us to delineate the functions of these two redundant pathways. It is unknown whether we can elucidate the contribution of a single pathway to the ever-growing network, i.e., can we untangle the network to understand the mechanisms by which different pathways intersect and contribute to biological processes? We will address this question in this application and we will further study the mechanisms by which the H2AX- and NBS1-dependent pathways act together to ensure cell survival and the completion of DNA repair. We propose the following specific aims: 1) determine whether NBS1 acts redundantly with the established H2AX-MDC1-RNF8-RNF168 pathway to ensure cell survival; 2) delineate the NBS1-dependent pathway; and 3) explore the mechanisms underlying cell lethality caused by NBS1 and H2AX co-depletion. These studies will not only allow us to understand the redundant functions of H2AX and NBS1 in vivo but will also reveal ways to investigate the functions of proteins and pathways in today’s complex signaling networks. Moreover, results from these studies will provide the rationale for exploiting DNA repair defect and applying synthetic lethality concept in precision medicine for cancer patients.

项目摘要 解密基因组不稳定性和肿瘤发生的分子机制是长期的 我实验室的目标。该提议的广泛目标反映了我们追求的全面 了解参与DNA修复的网络，并确定这些蛋白质和途径如何 相交，互动，交流，协调和协作进行基因组维持。短期目标是 对几种DNA损伤信号传导和修复途径进行详细的机械研究，这将 为实现利用DNA修复网络进行癌症治疗的长期目标提供基础。 该建议将定义两个重叠的DNA损伤途径，这对于 细胞存活。我们和其他研究人员已经构建了一个精致的信号通路，该途径在下游 H2AX并调节许多DNA损伤修复蛋白在DNA部位的募集和积累 休息。该H2AX依赖性途径由H2AX，MDC1，RNF8和RNF168组成。但是，维修 在H2AX-，MDC1-，RNF8-或RNF168缺乏细胞或小鼠中观察到的缺陷很温和，从而提高了可能性 招募这些下游修复涉及与H2AX无关的机制 蛋白质。我们建议这种独立于H2AX的途径由NBS1控制。 根据我们以前的研究和本提案中提出的初步数据，我们假设 H2AX-和NBS1依赖性途径参与DNA损伤响应，对于细胞至关重要 生存。我们认为，这两种途径具有多余的功能，尤其是在促进同源的方面 重组维修。但是，它们并不是完全分开的，因为它们在多个点相交。这 对于我们来说，描述这两种冗余途径的功能使我们变得巨大挑战。这是 未知我们是否可以阐明单个途径对不断增长的网络的贡献，即可以 我们解开网络以了解不同途径相交并贡献的机制 到生物过程？我们将在此应用程序中解决这个问题，我们将进一步研究 H2AX和NBS1依赖性途径共同作用以确保细胞存活和 DNA修复的完成。我们提出以下具体目的：1）确定NBS1是否行动 用已建立的H2AX-MDC1-RNF8-RNF168途径进行冗余，以确保细胞存活； 2）描述 NBS1依赖性途径； 3）探索NBS1和H2AX引起的细胞致死性的机制 共同消耗。这些研究不仅将使我们能够理解H2AX和NBS1的冗余功能 Vivo，但还将揭示在当今复杂的信号中研究蛋白质和途径功能的方法 网络。此外，这些研究的结果将为利用DNA修复缺陷和 在癌症患者的精确医学中应用合成致死概念。