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

基本信息

批准号：
10799054
负责人：
AZIZ SANCAR
金额：
$ 2.74万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
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

项目摘要

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. (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.

抽象的我们研究核苷酸切除修复和哺乳动物的分子机制昼夜节律。我们最近都取得了技术和机械进步在这两个领域，并获得了这两个方面的直接证据字段。我们在这两个领域的发现都直接适用于人类健康。我们将申请这些新目标的新进步：（1）我们为原始XR-Seq方法开发了更高的分辨率版本全基因组全基因组的单核苷酸分辨率映射所有DNA损伤的修复通过核苷酸切除修复处理，包括致癌物和化学治疗药物。此外，我们开发了类似的损坏式方法全基因组单核苷酸分辨率的DNA损伤映射。我们已经使用了两种方法的结合，以发现修复的热点和没有重叠损坏热点或冷点，并获得了有关基因组3D的新信息和维修。我们将继续描述这些功能以将修复与表观基因组联系起来标记，3D基因组组织，染色质状态和复制时间。（2）我们将定义哺乳动物昼夜节律时钟的分子机制。最近，我们证明了加密（哭泣），而不是周期（per）是哺乳动物转录翻译反馈回路（TTFL）中的阻遏物，根据特定基因而作为阻遏物或激活剂起作用，在哭泣中依赖方式。我们将进行实验，以在体外重新建立该模型具有纯化蛋白质的系统。（3）昼夜节律时钟，癌症和化学疗法。这是我们第一次能够用顺铂及其在包括肝组织在内的小鼠组织中绘制损伤形成，肾脏和肺，全基因组以及单核苷酸分辨率。我们使令人兴奋的发现对于大多数基因而言，转录的链（TS）和未转录的链（NT）在一天的不同时间进行维修。我们计划利用这一发现为了开发更有效的年度疗法方案，首先是结直肠癌，在用顺铂和奥沙利铂治疗的其他类型的癌症的未来。这拟议的研究具有创新性，因为它基于我们在领域的发现 DNA修复和昼夜节律，这很重要，因为它与癌症相关预防和治疗。