Processing and Repair of DNA Crosslinks

项目总结 DNA交联物，包括链间交联物(ICL)和DNA-蛋白质交联物(DPC)，都是DNA的形式 DNA中由内源和自然来源持续产生的损伤。必须按顺序移除它们 以实现准确的基因组复制和基因表达。多种化疗药物可诱发ICL 包括氮芥末及其衍生物(马法兰、百菌清)、补骨脂素、丝裂霉素C、铂- 以顺铂等为基础的化合物，以及BCNU等亚硝基化合物。生物多样性的识别与未来发展 与ICL修复熟练程度相关的生物标志物将促进个人的精准医疗 病人。尽管交联剂在癌症病因学和治疗中的重要性，但DNA交联剂的机制 修复只是大体知道，许多步骤都是假定的。一种综合的、程序化的方法 涉及四个研究项目和两个服务核心，将在 支持该计划，并单独和协同地为这一主题作出贡献。每一个整体 目标/具体目标由每个项目使用不同和互补的方法独立完成。 计划项目围绕三个目标组织，代表项目的目标： 目标1：确定如何使用或协调不同的交联链修复途径。该计划将 调查关于不同的交联链修复途径的主要知识差距，包括核酸酶或 复合体/组分被招募并在不同的情况下使用，在不同的情况下，交联剂修复的变化 细胞周期，不同构型的模型停滞复制叉处的交联链修复作用，无论ICL 修复对于不同的病变是不同的，并且无错误和突变的交联物修复的机制是不同的。目标2： 了解新发现的和鲜有研究的交叉链接修复组件的功能。一个街区到 了解ICL修复的进展是有一组已知涉及的组件 在交联链修复中，但机械性角色没有被分配或只是表面上知道的。在这个节目中， 调查人员将合作确定他们的职能。主要未知组件包括SLX4IP(它 与SLX4相关)；HMGB1、HMGB2和HMGB3 DNA结合蛋白；MSH2-MSH3复合体 (结合DNA扭曲)；以及uhrf1(被认为是运送核酸酶的替代支架)。 目的3：探讨DNA-蛋白质交联链的修复机制。可能会有几条路线 DPC修复和耐受性。将进行实验以确定不同的处理模式。主修 知识空白包括Fanconi贫血(FA)途径蛋白参与修复以及如何参与修复 FA的特征可能与DPC修复的缺陷有关。我们将调查Replicative参与其中 旁路(跨病变DNA合成)对DNA-多肽交联物的耐受性(蛋白水解法模拟 民主党议员)。我们还将探索预防或诱导DPC突变的途径。

PROJECT SUMMARY DNA crosslinks, including interstrand crosslinks (ICLs) and DNA-protein crosslinks (DPCs) are forms of DNA damage that arise continuously in DNA from endogenous and natural sources. They must be removed in order to allow accurate genome duplication and gene expression. Many chemotherapeutic agents induce ICLs including nitrogen mustards and derivatives (melphalan, chlorambucil), psoralens, mitomycin C, platinum- based compounds such as cisplatin, and nitrosoureas such as BCNU. Identification and future development of biomarkers associated with ICL repair proficiency will facilitate precision medical treatment for individual patients. Despite the importance of crosslinks in cancer etiology and treatment, mechanisms of DNA crosslink repair are known only in outline, and many steps are simply assumed. An integrated, programmatic approach involving four Research Projects and two service Cores will conduct experimental investigations under the auspices of the Program and contribute, both individually and synergistically, to this theme. Each Overall Goal/Specific Aim is independently engaged by each project using distinct and complementary approaches. The Program Project is organized around three aims, representing goals of the project: Aim 1: Determine how different pathways of crosslink repair are used or coordinated. The program will investigate major gaps in knowledge about different crosslink repair pathways, including how nucleases or complexes/components are recruited and used in different situations, variations of crosslink repair during the cell cycle, action of crosslink repair at different configurations of model stalled replication forks, whether ICL repair differs for different lesions, and the mechanism of error-free and mutagenic crosslink repair. Aim 2: Understand functions of newly discovered and little-studied crosslink repair components. One block to progress in understanding repair of ICLs is that there are a group of components that are known to be involved in crosslink repair, but where mechanistic roles are unassigned or known only superficially. In this program the investigators will cooperate to determine their functions. Major unknown components include SLX4IP (which associates with SLX4); the HMGB1, HMGB2 and HMGB3 DNA binding proteins; the MSH2-MSH3 complex (which binds DNA distortions); and UHRF1 (postulated as an alternative scaffold for delivery of nucleases). Aim 3: Investigate the mechanisms of repair of DNA-protein crosslinks. There are likely to be several routes of DPC repair and tolerance. Experiments will be undertaken to determine different modes of processing. Major gaps in knowledge include the involvement of Fanconi anemia (FA) pathway proteins in repair and how features of FA might be explained by defects in DPC repair. We will investigate involvement of replicative bypass (translesion DNA synthesis) in tolerance of DNA-peptide crosslinks (modeling proteolytically processed DPCs). We will also explore pathways that prevent or induce mutagenesis by DPCs.