Defining the mechanism and specificity of the 53BP1-Rev7 non-homologous end joining pathway in immunity and oncogenesis

定义 53BP1-Rev7 非同源末端连接途径在免疫和肿瘤发生中的机制和特异性

• 批准号: MR/R017549/1
• 负责人: Jonathan Chapman
• 金额: $ 90.39万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FR017549%2F1
• 关键词: Defining; mechanism; specificity; 53BP1; Rev7

The major aim of this research project is to refine our understanding of the 53BP1 pathway: a poorly understood sub-pathway of the vertebrate non-homologous end joining (NHEJ) DNA repair system that plays a vital role in the human adaptive immune response, yet also drives the initiation and progression of breast, ovarian and other tumours in patients harbouring a faulty copy of the BRCA1 tumour suppressor gene. A key objective of the project is to challenge a widely accepted paradigm for the molecular function of this pathway. We will set out to test a hypothesis that proposes an alternative explanation for this pathway's activity. Namely, that the single-stranded DNA enrichments detected at DNA double-strand break (DSB) sites in cells deficient for the 53BP1 pathway, do not represent product of a failure to protect DNA ends from resection as is widely perceived, but instead represents a structured DNA repair intermediate/substrate that cannot be overcome when the pathway fails. If correct, the genetically modified mice we plan to engineer will be immune-deficicient as a result of an inability to efficiently generate antibody diversity via 53BP1-dependent NHEJ. Nevertheless, cells from these animals will be able to survive and divide relatively healthily in the absence of the activity of BRCA1, a protein normally essential for sustaining normal cell proliferation and the maintenance of genome stability. Both scenarios will provide us with valuable biological tools with which we will attribute mechanism to the 53BP1 DNA repair system, in biological contexts directly related to human health and disease. Other distinct, yet complementary experiments will examine secondary predictions of our model, including one that may explain the context specificity of the 53BP1-dependent DNA repair system, thereby linking its immune system functions to its potent oncogenic activities in cancer.

该研究项目的主要目的是完善我们对53 BP 1途径的理解：脊椎动物非同源末端连接（NHEJ）DNA修复系统的一个鲜为人知的子途径，该系统在人类适应性免疫反应中起着至关重要的作用，但也推动了乳腺癌，卵巢癌和其他肿瘤的发生和发展。该项目的一个关键目标是挑战这一途径的分子功能的广泛接受的范式。我们将着手测试一个假设，提出了一个替代解释这一途径的活动。即，在53 BP 1途径缺陷的细胞中的DNA双链断裂（DSB）位点处检测到的单链DNA富集并不代表如广泛认为的保护DNA末端免于切除失败的产物，而是代表当途径失败时不能克服的结构化DNA修复中间体/底物。如果正确的话，我们计划工程改造的转基因小鼠将是免疫缺陷的，因为无法通过53 BP 1依赖性NHEJ有效地产生抗体多样性。然而，这些动物的细胞将能够在缺乏BRCA 1活性的情况下相对健康地存活和分裂，BRCA 1是一种通常对维持正常细胞增殖和维持基因组稳定性至关重要的蛋白质。这两种情况都将为我们提供宝贵的生物学工具，我们将利用这些工具在与人类健康和疾病直接相关的生物学背景下将机制归因于53 BP 1 DNA修复系统。其他不同但互补的实验将检查我们模型的次要预测，包括可能解释53 BP 1依赖性DNA修复系统的背景特异性的实验，从而将其免疫系统功能与其在癌症中的潜在致癌活性联系起来。

项目成果

Mechanism of 53BP1 activity regulation by RNA-binding TIRR and a designer protein.

• DOI: 10.1038/s41594-018-0083-z
• 发表时间: 2018-07
• 期刊: Nature structural & molecular biology
• 影响因子: 16.8
• 作者: Botuyan MV;Cui G;Drané P;Oliveira C;Detappe A;Brault ME;Parnandi N;Chaubey S;Thompson JR;Bragantini B;Zhao D;Chapman JR;Chowdhury D;Mer G
• 通讯作者: Mer G

53BP1 cooperation with the REV7-shieldin complex underpins DNA structure-specific NHEJ.

• DOI: 10.1038/s41586-018-0362-1
• 发表时间: 2018-08
• 期刊: Nature
• 影响因子: 64.8
• 作者: Ghezraoui H;Oliveira C;Becker JR;Bilham K;Moralli D;Anzilotti C;Fischer R;Deobagkar-Lele M;Sanchiz-Calvo M;Fueyo-Marcos E;Bonham S;Kessler BM;Rottenberg S;Cornall RJ;Green CM;Chapman JR
• 通讯作者: Chapman JR

The CST Complex Mediates End Protection at Double-Strand Breaks and Promotes PARP Inhibitor Sensitivity in BRCA1-Deficient Cells.

• DOI: 10.1016/j.celrep.2018.04.046
• 发表时间: 2018-05-15
• 期刊: Cell reports
• 影响因子: 8.8
• 作者: Barazas M;Annunziato S;Pettitt SJ;de Krijger I;Ghezraoui H;Roobol SJ;Lutz C;Frankum J;Song FF;Brough R;Evers B;Gogola E;Bhin J;van de Ven M;van Gent DC;Jacobs JJL;Chapman R;Lord CJ;Jonkers J;Rottenberg S
• 通讯作者: Rottenberg S