Structural and mechanistic studies of the breast cancer tumour suppressor BRCA2 in DNA double strand break repair

乳腺癌抑癌基因BRCA2在DNA双链断裂修复中的结构和机制研究

• 批准号: MR/J001201/1
• 负责人: Xiaodong Zhang
• 金额: $ 40.38万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FJ001201%2F1
• 关键词: Structural; mechanistic; studies; breast; cancer

About 10% of breast cancers are due to genetic mutations that predispose these individuals to the cancer. Of these familial cases, 30-50% are associated with mutations in two breast cancer susceptibility genes, brca1 and brca2. For germ line brca2 mutations, the cumulative risk for breast cancer is as high as 50% and 10-15% for ovarian cancer. Since its discovery, brca2 and the 3418 amino acid protein it encodes (BRCA2) have been the subject of intense study. BRCA2 plays important roles in homologous recombination, a key mechanism in DNA damage repair. It carries out its function through interactions with other key components such as PALB2 and RAD51. It is therefore becoming clear that information on its interactions with these partners will be required in order to understand the mechanism and functions in the context of efficient DNA repair and tumourigenesis. Due to the large size and low abundance of BRCA2, it has been extremely challenging to purify the full length protein, which has hindered its biochemical, structural and mechanistic characterization. However, very recently, three groups have reported the purification and biochemical characterization of BRCA2, creating an exciting opportunity for structural studies. In this proposed research, we will employ electron microscopy single particle analysis to characterize the structures of BRCA2 alone and its complexes with RAD51 and PALB2 on ssDNA in order to provide a molecular basis for its roles in double-strand break repair and breast cancer. The information obtained will not only provide us with the first glimpse of the structures of this important protein and its interacting partners, but also reveal insights into how BRCA2 helps to load RAD51 onto single stranded DNA that eventually leads to strand invasion and homologous recombination. This will constitute a significant step forward in our understanding of this key cellular process that has a direct link to cancer and aging. It will improve our knowledge about the cause of the disease and also offer opportunities for novel therapeutic approaches for DNA damage repair mechanisms with direct consequences for cancer patients.

大约10%的乳腺癌是由于基因突变导致的，这些基因突变使这些人易患癌症。在这些家族性病例中，30-50%与两种乳腺癌易感基因brca1和brca2的突变有关。对于生殖系brca2突变，乳腺癌的累积风险高达50%，卵巢癌的累积风险高达10-15%。自发现以来，brca2及其编码的3418氨基酸蛋白（brca2）一直是深入研究的主题。BRCA2在同源重组中发挥重要作用，同源重组是DNA损伤修复的关键机制。它通过与PALB2和RAD51等其他关键组件的交互来实现其功能。因此，越来越清楚的是，为了了解有效DNA修复和肿瘤发生的机制和功能，将需要有关其与这些伙伴相互作用的信息。由于BRCA2的大尺寸和低丰度，纯化全长蛋白极具挑战性，这阻碍了其生化，结构和机制表征。然而，最近，三个小组报道了BRCA2的纯化和生化表征，为结构研究创造了一个令人兴奋的机会。在本研究中，我们将采用电子显微镜单粒子分析来表征BRCA2单独及其与RAD51和PALB2在ssDNA上的复合物的结构，为其在双链断裂修复和乳腺癌中的作用提供分子基础。获得的信息不仅将为我们提供这种重要蛋白质及其相互作用伙伴的结构的第一眼，而且还揭示了BRCA2如何帮助将RAD51加载到单链DNA上，最终导致链入侵和同源重组。这将使我们对与癌症和衰老有直接联系的关键细胞过程的理解向前迈出重要的一步。这将提高我们对疾病原因的认识，也为DNA损伤修复机制的新治疗方法提供了机会，对癌症患者有直接影响。

项目成果

Visualization of direct and diffusion-assisted RAD51 nucleation by full-length human BRCA2 protein

• DOI: 10.1016/j.molcel.2023.06.031
• 发表时间: 2023-07
• 期刊: Molecular cell
• 影响因子: 16
• 作者: O. Beláň;Luke A. Greenhough;L. Kuhlen;Roopesh Anand;Artur Kaczmarczyk;D. Gruszka;H. Yardimci;Xiaodong Zhang;David S. Rueda;S. West;S. Boulton

The Dimeric Architecture of Checkpoint Kinases Mec1ATR and Tel1ATM Reveal a Common Structural Organization.

• DOI: 10.1074/jbc.m115.708263
• 发表时间: 2016-06-24
• 期刊: The Journal of biological chemistry
• 作者: Sawicka M;Wanrooij PH;Darbari VC;Tannous E;Hailemariam S;Bose D;Makarova AV;Burgers PM;Zhang X
• 通讯作者: Zhang X

Structure and mechanism of action of the BRCA2 breast cancer tumor suppressor.

• DOI: 10.1038/nsmb.2899
• 发表时间: 2014-11
• 期刊: Nature structural & molecular biology
• 影响因子: 16.8
• 作者: Shahid T;Soroka J;Kong E;Malivert L;McIlwraith MJ;Pape T;West SC;Zhang X
• 通讯作者: Zhang X

A second DNA binding site in human BRCA2 promotes homologous recombination.

• DOI: 10.1038/ncomms12813
• 发表时间: 2016-09-15
• 期刊: NATURE COMMUNICATIONS
• 影响因子: 16.6
• 作者: von Nicolai, Catharina;Ehlen, Asa;Martin, Charlotte;Zhang, Xiaodong;Carreira, Aura
• 通讯作者: Carreira, Aura

Single-Particle Electron Microscopy Analysis of DNA Repair Complexes.

• DOI: 10.1016/bs.mie.2017.03.010
• 发表时间: 2017
• 期刊: Methods in enzymology
• 作者: M. Sawicka;R. Aramayo;Rafael Ayala;R. Glyde;Xiaodong Zhang