Defining the contributions of BRCA1, BRCA2, and RAD52 to genome stability

项目摘要 我们的染色体不断受到各种各样的侮辱，造成的损害，必须是 修复.出于必要，细胞已经进化出检测和修复DNA断裂链的机制， 防止重要遗传信息的丢失。双链DNA断裂（DSB）是一种 可能导致特别灾难性后果的损害。如果不纠正，DSB可能导致严重的 染色体重排，这是所有癌症的标志。事实上，人力资源相关的缺陷 蛋白质与几种严重的遗传疾病有关。患有这些疾病的患者通常会表现出 由于基因组完整性的丧失而具有发展癌症的强烈倾向。令人惊讶的是，DNA 复制是DSB的主要来源，因此快速生长的细胞尤其是 依赖于同源DNA重组生存。这种对同源的依赖 快速生长细胞的生存重组突出了利用重组的潜力 抑制剂作为高选择性抗癌疗法。为了开发同源的临床潜力， 重组抑制剂，这将是至关重要的，我们更充分地了解的分子基础， 参与调控重组的蛋白质。 为了帮助更好地理解同源DNA重组的分子基础，我们开发了 强大的新实验平台，使我们能够直接可视化数百个单独的DNA， 在单分子水平上。我们正在利用这些独特的研究工具来探索 蛋白质-核酸相互作用的基础，重点放在理解与 人类生物学和疾病。我们已经使用这些测定来研究人RAD 51，其结合于单- 形成一个关键的重组中间体，称为突触前复合体。在这里，我们将 评估含有肿瘤抑制蛋白复合物BRCA 1-BARD 1、BRCA 2-BARD 1和BRCA 3-BARD 2的复合物如何影响肿瘤抑制蛋白复合物的功能。 DSS 1和PALB 2通过调节RAD 51的活性促进同源重组 突触前复合体我们还将研究如何蛋白质RAD 52，这是新认识到的一个新的蛋白质。 作为抗癌药物的重要靶点，与RAD 51、BRCA 1-BARD 1、BRCA 2-DSS 1和 PALB 2.我们还将研究蛋白质RADX，它正在成为基因组完整性的关键参与者， 功能下调RAD 51活性。我们将通过直接可视化这些 使用光学显微镜进行实时处理。这些研究提供了重要的新的潜力， 深入了解BRCA 1-BARD 1、BRCA 2-DSS 1、PALB 2和RAD 52如何调节同源 重组和支持人类基因组完整性。

Project Summary Our chromosomes are continually bombarded with a variety of insults, resulting in damage that must be repaired. By necessity, cells have evolved mechanisms to detect and repair broken strands of DNA, thereby preventing loss of important genetic information. Double-stranded DNA breaks (DSBs) are a type of damage that can result in particularly disastrous outcomes. If not corrected, DSBs can lead to gross chromosomal rearrangements, which are the hallmark of all forms of cancer. Indeed, defects in HR-related proteins are associated with several severe genetic diseases. Patients with these diseases often exhibit a strong predisposition for developing cancers due to a loss of genome integrity. Surprisingly, DNA replication is the primary source of DSBs, and as a consequence rapidly growing cells are especially dependent upon homologous DNA recombination for survival. This dependence upon homologous recombination for the survival of rapidly growing cells highlights the potential for using recombination inhibitors as highly selective anti-cancer therapies. To exploit the clinical potential of homologous recombination inhibitors it will be essential that we more fully understand the molecular underpinnings of the proteins that are involved in regulating and controlling recombination. To help better understand the molecular basis of homologous DNA recombination we have developed powerful new experimental platforms that allow us to directly visualize hundreds of individual DNA molecules at the single molecule level. We are utilizing these unique research tools to probe the fundamental basis for protein-nucleic acid interactions, with emphasis placed upon understanding reactions relevant to human biology and disease. We have used these assays to study human RAD51, which binds to single- stranded DNA forming a key recombination intermediate called the presynaptic complex. Here, we will assess how complexes containing the tumor suppressor protein complexes BRCA1-BARD1, BRCA2- DSS1, and PALB2 promote homologous recombination by regulating the activities of the RAD51 presynaptic complex. We will also examine how the protein RAD52, which newly recognized as an important target for anti-cancer drugs, interacts with RAD51, BRCA1-BARD1, BRCA2-DSS1, and PALB2. We will also study the protein RADX, which is emerging as a key player in genome integrity which functions to downregulate RAD51 activity. We will accomplish these goals by directly visualizing these processes in real-time using optical microscopy. These studies offer the potential for significant new insights into how BRCA1-BARD1, BRCA2-DSS1, PALB2 and RAD52 regulate homologous recombination and support human genome integrity.