Mechanisms of Genome Integrity

项目总结 我们的染色体不断地受到各种侮辱的轰炸，导致损害 一定要修好。细胞已经进化出检测和修复断裂DNA链的机制， 从而防止重要遗传信息的丢失。双链DNA断裂(DSB) 是一种会导致特别灾难性后果的损害。如果不纠正，DSB可能会 引起严重的染色体重排，这是所有形式癌症的标志。 同源重组(HR)是细胞修复DSB的一条保守途径， 而HR对于防止和修复DNA复制过程中出现的损伤是必要的。什么时候 发生DSB时，DNA末端被处理以产生3‘单链DNA(SsDNA)突出物。 然后，单链DNA末端与基因组其他地方的同源序列配对，缺失的 使用同源DNA作为复制模板来替换DNA。最后，复制的 中间体被分解，重新生成断裂的DNA的连续性。人力资源部门要求 负责感知损伤的一系列复杂蛋白质的协调作用， 招募要素，处理和修复受损的DNA。后果是什么？ 对人力资源的破坏是毁灭性的。例如，RAD51重组酶的突变是 小鼠的胚胎是致命的，人类RAD51的突变与乳腺癌有关。在……里面 此外，BRCA2缺陷至少占所有乳腺癌的5%，也赋予了一种基因 卵巢癌的易感性。BRCA2被认为有助于调节HR，而这一点的丧失 监管可能是该基因与遗传性癌症相关的原因。新的发现将 有必要充分理解这些结果的机制基础。 我们的研究项目专注于了解蛋白质如何感知和响应 受损的DNA，然后修复受损的DNA，以防止可能导致 癌症。为了帮助解决这些问题，我们开发了独特的技术，使我们能够 使用光学显微镜直接显示数百个单独的分子，这使我们能够 实时监测DNA修复和DNA复制的时空进程 在单分子水平上。使用这种方法，我们试图定义基本机制 我们的细胞用来复制和修复DNA，其长期目标是了解 这些过程中的错误可能会导致染色体重排。

PROJECT SUMMARY Our chromosomes are constantly bombarded with a variety of insults, resulting in damage that must be repaired. 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 lead to particularly disastrous outcomes. If not corrected, DSBs can cause gross chromosomal rearrangements, which are the hallmark of all forms of cancer. Homologous recombination (HR) is a conserved pathway that cells can use to repair DSBs, and HR is necessary to prevent and repair the damage that arises during DNA replication. When a DSB occurs, the DNA ends are processed to generate 3' single‐strand DNA (ssDNA) overhangs. The ssDNA ends then pair with homologous sequence elsewhere in the genome, and the missing DNA is replaced using the homologous DNA as a template for replication. Finally, the replicated intermediate is resolved, regenerating the continuity of the broken DNA. HR requires the coordinated action of a complex repertoire of proteins, which are responsible for sensing damage, recruiting essential factors, and processing and repairing the damaged DNA. The consequences of disrupting HR are devastating. For example, mutations in the RAD51 recombinase are embryonic lethal in mice, and mutations in human RAD51 are linked to breast cancers. In addition, defects in BRCA2 account for at least 5% of all breast cancers and also confer a genetic predisposition to ovarian cancer. BRCA2 is thought to help regulate HR, and loss of this regulation may be the reason why this gene is linked to hereditary cancers. New discoveries will be necessary to fully understand the mechanistic basis for these outcomes. Our research program is focused on understanding how proteins sense and respond to damaged DNA and they then repair the damaged DNA to prevent mutations that can lead to cancer. To help address these problems we have developed unique technologies that allow us to directly visualize hundreds of individual molecules using optical microscopy, which enables us to monitor the spatial and temporal progression of DNA repair and DNA replication in real‐time at the single‐molecule level. Using this approach, we seek to define the fundamental mechanisms that our cells use to replicate and repair DNA, with the long‐term goal of understanding how errors during these processes can lead to chromosomal rearrangements.