Genomic Instability

基因组不稳定性

• 批准号: 6668736
• 负责人: Vilhelm A Bohr
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6668736
• 关键词: DNA damage; DNA repair; aging; genome; oncoprotein p21; proliferating cell nuclear antigen; tissue /cell culture

Summary of work: Genomic instability arises from several sources. These include problems with DNA repair, transcription and replication. They also include deficiencies in the topological metabolism of DNA, which is controlled by a number of DNA metabolic enzymes. A group of these are topoisomerases, and we have been interested in their function as it relates to the handling of DNA damage. Several recent studies have shown that human topoisomerase I (htopoI) can recognize various DNA lesions and thereby form a covalent topoisomerase I-DNA complex, which is known to be detrimental to cells. We have investigated whether htopoI recognizes another htopoI that is covalently trapped on a DNA substrate. For this purpose we created an artificial DNA substrate containing a specific topoisomerase I binding sequence, where the enzyme was trapped in the covalently bound form. We demonstrate that, in vitro, free htopoI stimulates the formation of an additional cleavage complex immediately upstream of the covalently bound topoisomerase I. We also study genomic instability at the population level and how this changes with aging. This is done in DNA from humans enrolled in the Baltimore Longitudinal Study on Aging. Here we measure a number of polymorphisms in DNA repair genes to determine if there are significant changes with aging or with age-associated diseases. In particular, we have focused on polymorphisms in the gene for the human premature aging disorder, Werner syndrome. So far we have not observed any connections between specific polymorphisms and age associated diseases but only a few polymorphisms have been examined, and we plan to look at many more

工作总结：基因组不稳定性有几个来源。这些问题包括DNA修复，转录和复制。它们还包括DNA拓扑代谢的缺陷，其由许多DNA代谢酶控制。其中一组是拓扑异构酶，我们一直对它们的功能感兴趣，因为它与DNA损伤的处理有关。最近的几项研究表明，人类拓扑异构酶I（htopoI）可以识别各种DNA损伤，从而形成共价拓扑异构酶I-DNA复合物，这是已知的是有害的细胞。我们已经研究了htopoI是否识别另一个htopoI是共价捕获的DNA基板上。为此目的，我们创建了一个人工DNA基板含有特定的拓扑异构酶I结合序列，其中的酶被困在共价结合的形式。我们证明，在体外，自由htopoI刺激形成一个额外的切割复合物的共价结合的拓扑异构酶I的上游。我们还研究了群体水平上的基因组不稳定性以及这种不稳定性如何随着衰老而变化。这是在参加巴尔的摩老龄化纵向研究的人的DNA中完成的。在这里，我们测量了DNA修复基因的一些多态性，以确定是否有显着的变化与衰老或与年龄相关的疾病。特别是，我们集中在基因多态性的人类过早衰老疾病，沃纳综合征。到目前为止，我们还没有观察到任何特定的多态性和年龄相关疾病之间的联系，但只有少数多态性已被检查，我们计划看看更多