Helicase regulation during homologous recombination

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， 从而防止重要遗传信息的丢失。双链DNA断裂（DSB）是一种 导致了特别灾难性的后果。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，人力资源的缺陷- 相关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 由于基因组完整性的丧失而表现出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，快速生长的细胞特别容易发生DSB。 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 抑制剂作为高度选择性的癌症疗法。为了充分利用同源的临床潜力， 重组抑制剂，这将是至关重要的，我们更充分地了解详细的分子 重组的基础以及参与调控的蛋白质 过程 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-核酸相互作用的基本基础，重点放在理解 与人类生物学和疾病有关的反应。在这里，我们将评估ATP依赖性解旋酶如何 发挥“抗重组酶”活性，通过拆除关键酶调控同源重组 重组中间体我们将通过在真实的中直接可视化这些过程来实现这一目标- 时间使用光学显微镜。我们将分析影响抗重组酶功能的因素， 特异性，我们将精确地确定反重组酶如何拆除重组中间体， 我们将寻求建立对不同真核生物之间保守的共同主题的理解， 抗重组酶，以及定义这些蛋白质的独特属性， 对人类健康的影响。我们将寻求确定与这些问题相关的详细分子信息， 这个项目的部分意义在于我们努力获得的答案的深度。

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 led to 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 cancer therapies. To fully exploit the clinical potential of homologous recombination inhibitors it will be essential that we more fully understand the detail molecular underpinnings of recombination and the proteins that are involved in regulating and controlling this process. 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. Here we will assess how ATP-dependent helicases can exert “antirecombinase” activities and regulate homologous recombination by dismantling key recombination intermediates. We will accomplish this goal by directly visualizing these processes in real- time using optical microscopy. We will analyze factors that influence antirecombinase function and specificity, we will determine precisely how antirecombinases dismantle recombination intermediates, and we will seek to establish an understanding of common themes conserved among different eukaryotic antirecombinases, as well as define the unique attributes of those proteins that are of particular importance to human health. We will seek to determine detailed molecular information related to these questions, and part of the significance of this project lies in the depth of the answers we strive to obtain.