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

工作摘要：基因组不稳定性来自多种来源。这些包括DNA修复，转录和复制问题。它们还包括DNA拓扑代谢中的缺陷，该代谢由多种DNA代谢酶控制。其中一组是拓扑异构酶，我们对它们的功能感兴趣，因为它与处理DNA损伤有关。最近的一些研究表明，人拓扑异构酶I（Htopoi）可以识别各种DNA病变，从而形成共价拓扑异构酶I-DNA复合物，该复合物已知对细胞有害。我们已经研究了Htopoi是否认识到另一个被共价捕获在DNA底物上的Htopoi。为此，我们创建了一个人工DNA底物，其中包含特定的拓扑异构酶I结合序列，其中酶以共价结合形式被困。我们证明，在体外，游离htopoi刺激了立即结合的拓扑异构酶上游的附加裂解复合物的形成。我们还研究了种群水平上的基因组不稳定性，以及随着衰老的变化。这是在巴尔的摩纵向衰老纵向研究的人类的DNA中完成的。在这里，我们测量了DNA修复基因中的许多多态性，以确定衰老或与年龄相关的疾病发生显着变化。特别是，我们专注于人类过早衰老疾病的基因中的多态性，Werner综合征。到目前为止