Molecular Mechanism of Mammalian DNA Excision Repair and the Circadian Clock

哺乳动物DNA切除修复和生物钟的分子机制

• 批准号: 10687262
• 负责人: AZIZ SANCAR
• 金额: $ 100.27万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10687262
• 关键词: 3-Dimensional; Area; Biochemical; Carcinogens; Chromatin; Chronotherapy; Cisplatin; Colorectal Cancer; DNA; DNA Damage; DNA Repair; DNA mapping; Diptera; Drosophila genus; Excision Repair; Feedback; Future; Genes; Genetic Transcription; Genome; Genomics; Goals; Health; Human; In Vitro; Insecta; Kidney; Link; Liver; Lung; Maps; Methods; Modeling; Molecular; Mus; Nucleotide Excision Repair; Nucleotides; Pharmaceutical Preparations; Process; Regimen; Regulation; Research; Resolution; Spottings; System; Technology; Therapeutic; Time; Tissues; Transcription-Coupled Repair; Translations; Work; cancer prevention; cancer therapy; cancer type; chemotherapy; circadian pacemaker; cryptochrome; epigenomics; experimental study; genetic approach; genome-wide; innovation; novel; oxaliplatin; protein purification; reconstitution; repaired

PROJECT SUMMARY/ABSTRACT We work on molecular mechanisms of nucleotide excision repair and the mammalian circadian clock. We have recently made both the technological and mechanistic progress in both of these areas and obtained direct evidence of inter-connectedness of these two fields. Our findings in both fields are directly applicable to human health. We will apply these new advances for the following objectives: (1) We have developed higher resolution versions of our original XR-seq method for genome-wide single- nucleotide resolution mapping of repair of all DNA damage that is processed by nucleotide excision repair, including damage induced by carcinogens and chemotherapeutic drugs. In addition, we developed Damage-seq methods for similarly genome-wide single nucleotide resolution mapping of DNA damage. We have used the combination of the two methods to discover repair hotspots and coldspots that do not overlap damage hotspots or coldspots and have gained novel information on genome 3D and repair. We will continue characterizing these features to link repair to epigenomic markers, 3D genome organization, chromatin states, and replication timing. XR-seq has also enabled us to discover a novel transcription-coupled repair mechanism in Drosophila and other insects in the order Diptera. We will use biochemical and genetic approaches to solve the mechanism of this novel repair system. (2) We will define the molecular mechanism of the mammalian circadian clock. Recently, we demonstrated that Cryptochrome (CRY), and not Period (PER), is the repressor in the mammalian transcription-translation feedback loop (TTFL), and that PER acts either as a repressor or an activator, depending on the particular gene, in a CRY-dependent manner. We will carry out experiments to reconstitute this model in an in vitro system with purified proteins. (3) Circadian clock, cancer, and chemotherapy. For the first time, we have been able to map both damage formation by cisplatin and its repair in mouse tissues including liver, kidney, and lung, genome-wide and at single- nucleotide resolution. We made the exciting discovery that for most genes the transcribed strand (TS) and non- transcribed strand (NTS) are repaired at different times of the day. We plan to take advantage of this finding to develop more efficient chronotherapy regimens, first for colorectal cancers, and in the future for other types of cancers that are treated with cisplatin and oxaliplatin. The proposed research is innovative because it is based on our discoveries in the fields of DNA repair and circadian clock, and it is significant because of its relevance for cancer prevention and treatment.

项目总结/摘要 我们研究核苷酸切除修复和哺乳动物生物钟的分子机制。我们有 最近在这两个领域都取得了技术和机械方面的进展，并获得了直接的 这两个领域相互关联的证据。我们在这两个领域的发现都直接适用于人类 健康我们将把这些新进展应用于以下目标： (1)我们已经开发了更高分辨率版本的原始XR-seq方法，用于全基因组单克隆测序。 通过核苷酸切除修复处理的所有DNA损伤的修复的核苷酸分辨率作图， 包括致癌物和化疗药物引起的损伤。此外，我们还开发了Damage-seq 类似的全基因组DNA损伤单核苷酸分辨率作图方法。我们已经使用了 两种方法的组合，以发现修复热点和不重叠的损伤热点的冷点 或冷点，并获得了关于基因组3D和修复的新信息。我们将继续描述这些 将修复与表观基因组标记、3D基因组组织、染色质状态和复制时间联系起来的功能。 XR-seq还使我们能够在果蝇和其他哺乳动物中发现一种新的转录偶联修复机制。 双翅目的昆虫。我们将利用生物化学和遗传学的方法来解决这一机制 新型修复系统 (2)我们将定义哺乳动物生物钟的分子机制。最近，我们展示了 隐花色素（CRY），而不是周期（PER），是哺乳动物转录-翻译中的阻遏物， 反馈环（TTFL），并且PER作为阻遏物或激活物，取决于特定的基因， 以一种依赖性的方式。我们将进行实验，在体外系统中重建该模型， 纯化的蛋白质。 (3)生物钟、癌症和化疗。我们第一次能够同时绘制出 顺铂的形成及其在小鼠组织（包括肝、肾和肺）中的修复，全基因组和单基因组 核苷酸分辨率。我们有了一个令人兴奋的发现，对于大多数基因，转录链（TS）和非转录链（Non- 转录链（NTS）在一天中的不同时间被修复。我们计划利用这一发现， 开发更有效的时间治疗方案，首先用于结直肠癌，将来用于其他类型的癌症。 用顺铂和奥沙利铂治疗的癌症。这项研究是创新的，因为它是基于 我们在DNA修复和生物钟领域的发现，这是重要的，因为它的相关性， 用于癌症预防和治疗。