Coordination of DNA repair and transcription by ubiquitin modification at DNA double strand breaks

DNA 双链断裂处泛素修饰协调 DNA 修复和转录

• 批准号: 10380138
• 负责人: Bin Wang
• 金额: $ 36.32万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10380138
• 关键词: BRCA1 gene; Cells; Characteristics; Chromatin; Complex; DNA; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Repair Gene; DNA Repair Inhibition; Defect; Detection; Disease; Event; Failure; Genetic Transcription; Genome; Genome Stability; Goals; Health; Histone H2A; Human; Individual; Ionizing radiation; Lead; Lesion; Link; Lysine; Mediating; Methionine; Modeling; Modification; Monoubiquitination; Mutation; N-terminal; Pathway interactions; Play; Polyubiquitin; Polyubiquitination; Post-Translational Protein Processing; Production; Proteins; Reader; Regulation; Role; Signal Transduction; Site; System; Transcript; Translations; Ubiquitin; Ubiquitination; ataxia telangiectasia mutated protein; cytotoxic; design; gene repression; genome integrity; improved; insight; novel; p53-binding protein 1; prevent; recruit; repaired; response; restriction enzyme; tool

ABSTRACT DNA double-strand breaks (DSBs) are one of the most deleterious lesions. The cellular responses to DSBs involve a sophisticated DNA damage response network that detects, signals and repairs the lesion; failure of this system results in mutation, deletion and other alteration of genome and underlies many diseases. Post- translational modifications by covalent attachment of ubiquitin to proteins, known as ubiquitination, play important regulatory roles in the DNA damage response. Previous studies, including ours, have illustrated that, upon DSBs detection and activation of the DNA damage response kinase ATM, Lys63-linked ubiquitination of histone H2A/H2AX on damaged chromatin is critical in recruiting DNA damage repair proteins, including 53BP1 and BRCA1, to the damage sites. However, much remains unknown about the complexity of ubiquitin modifications and their roles in the DNA damage response. We have discovered that Lys11-linkage–specific ubiquitin modification occurs on damaged chromatin that regulates repression of transcription at DSBs, revealing Lys11-linkage ubiquitin modification as a new signaling and regulatory platform in the response to DSBs. We further showed that this modification is ATM dependent and catalyzed by RNF8 and Ube2S. In addition, cells deficient in Lys11-linkage ubiquitin modification displayed increased sensitivity to ionizing radiation. It indicates a model that DNA repair and transcription can be regulated by distinct linkage-specific ubiquitin modifications at DSBs. However, it is not clear whether these two seemingly parallel linkage-specific ubiquitination pathways are coordinated to regulate DNA repair and transcription in the cellular responses to DSBs. The objective of this proposal is to identify the crosstalk between Lys63- and Lys11-linkage modification on damaged chromatin and determine the underlying mechanisms through which it coordinates transcriptional repression and DNA repair. We will pursue the following specific aims: 1) determine the crosstalk between Lys11- and Lys63-linkage ubiquitination mediated by Cezanne to regulate DNA repair; 2) determine additional mechanisms underlying the coordination of DNA repair and transcriptional inhibition; 3) determine the role of Lys11- and Lys63-linkage ubiquitination at defined DSB sites in regulating DNA repair and inhibition of transcription. Our findings should provide novel insights into the understanding of how ubiquitin modification at DSBs is involved in signaling events to regulate inhibition of transcription and repair. Our long-term goal is to decipher the complex DNA response network that protects genome integrity, which is essential for design of tools and treatment to improve human health.

抽象的 DNA双链断裂（DSB）是最删除的病变之一。对DSB的细胞反应 涉及一个复杂的DNA损伤响应网络，该网络检测，信号和修复病变；失败 该系统导致基因组的突变，缺失和其他改变，并构成许多疾病。邮政- 通过将泛素的共价附着（称为泛素化）的共价附着来进行翻译修饰 DNA损伤反应中的重要调节作用。以前的研究，包括我们的研究，都说明了， DSB检测和激活DNA损伤反应激酶ATM，LYS63连接的泛素化 损坏的染色质上的Hisstone H2A/H2AX对于招募DNA损伤修复蛋白至关重要，包括 53BP1和BRCA1到损坏位点。但是，对泛素的复杂性仍然未知 修饰及其在DNA损伤反应中的作用。我们发现lys11-link-tempific 泛素修饰发生在受损的染色质上，该染色质调节DSBS的转录表达， 揭示Lys11连接泛素修饰是一种新的信号传导和调节平台 DSB。我们进一步表明，这种修饰取决于ATM，并由RNF8和UBE2S催化。在 此外，缺乏Lys11-链接泛素修饰的细胞显示出对电离的敏感性提高 辐射。它表明一个模型，即DNA修复和转录可以通过不同的连锁特定的调节 DSBS的泛素修饰。但是，目前尚不清楚这两个看似平行的链接是否特定于 泛素化途径是协调的，以调节细胞对的DNA修复和转录 DSB。该建议的目的是确定Lys63-和Lys11-Linkage修改之间的串扰 关于损坏的染色质并确定其协调转录的基本机制 抑制和DNA修复。我们将追求以下特定目标：1）确定 塞尚（Cezanne）介导的DNA修复介导的Lys11-和Lys63-LINK泛素化； 2）确定其他 DNA修复和转录抑制协调的基础机制； 3）确定 在调节性DNA修复中定义的DSB位点的Lys11-和Lys63-LINK泛素化和抑制 转录。我们的发现应该为理解泛素修饰的理解提供新颖的见解 DSB参与信号事件以调节转录和修复的抑制。我们的长期目标是 破译保护基因组完整性的复杂DNA响应网络，这对于设计至关重要 工具和治疗以改善人类健康。