MITOCHONDRIAL DNA DAMAGE AND REPAIR

线粒体 DNA 损伤与修复

• 批准号: 6575679
• 负责人: DANIEL F. BOGENHAGEN
• 金额: $ 21.9万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6575679
• 关键词: DNA damage; DNA directed DNA polymerase; DNA repair; DNA replication; adenine; cytosine; endonuclease; environmental toxicology; enzyme activity; mitochondrial DNA; mitochondrial disease /disorder; molecular genetics; oxidative stress

Mitochondrial DNA is a frequent target of chemical damage. Base loss, oxidative damage and reaction with carcinogenic compounds such as benzo(a)pyrene and aflatoxin are thought to occur at rates equal to or greater than the corresponding rates of damage to nuclear DNA. Mitochondria are able to repair some types of DNA damage, such as abasic sites and oxidative lesions (e.g., 8-oxo-dG), but probably not others. Very little is known concerning the enzymology of DNA repair in mitochondria. Replication through DNA adducts or attempts at repair may contribute to the incidence of point mutations and deletions observed in a growing list of human diseases. These diseases range from point mutations associated with rare neuromuscular diseases identified with the acronyms MELAS, MERRF, and NARP to large deletions observed in Kearns Sayre Syndrome. Recent studies have found a correlation between mtDNA damage and type 11 diabetes, Parkinson's disease and aging, although more research is required to establish a role for mtDNA damage in the etiology of these conditions. We propose to investigate the effects of specifically localized lesions in DNA templates prepared by our collaborators in this project on DNA replication by the purified mitochondrial DNA polymerase gamma. These studies will employ templates containing abasic sites, 8-oxo-dG, aminofluorene and benzo(a)pyrene adducts. We will also search for accessory factors that may facilitate translesional synthesis by DNA polymerase gamma. We propose experiments to characterize enzymes involved in mtDNA repair and to attempt to reconstitute repair of abasic sites or 8-oxo-dG lesions in mtDNA. Certain lesions, such as cyclobutane pyrimidine dimers in mtDNA are not thought to be repaired efficiently. We will attempt to increase the efficiency of repair by using molecular genetic techniques to direct repair enzymes such as photolyase or T4 endonuclease (denV) to mitochondria.

线粒体DNA是化学损伤的常见目标。基本损失， 氧化损伤和与致癌化合物的反应，例如 认为苯并（a）pyrene和黄曲霉毒素的发生率等于或 大于核DNA损伤的相应速率。 线粒体能够修复某些类型的DNA损伤，例如Abasic 部位和氧化病变（例如8-oxo-dg），但可能没有其他病变。 关于DNA修复酶的酶学知之甚​​少 线粒体。通过DNA加合物或修复尝试的复制可能 有助于观察到的点突变和缺失的发生率 越来越多的人类疾病清单。这些疾病范围从点 与罕见的神经肌肉疾病相关的突变 首字母缩写Melas，Merrf和NARP到Kearns观察到的大删除 赛尔综合症。最近的研究发现mtDNA之间存在相关性 损害和11型糖尿病，帕金森氏病和衰老，尽管更多 需要进行研究以确立麦克热答损伤的作用 这些条件。我们建议研究 由我们制备的DNA模板中的特定局部病变 纯化的有关DNA复制项目的合作者 线粒体DNA聚合酶γ。这些研究将采用模板 包含无碱性位点，8-氧气-DG，氨基氟和苯并（a）pyrene 加合物。我们还将搜索可能有助于 DNA聚合酶伽马的跨性别合成。我们提出了实验 表征参与mtDNA修复的酶，并尝试 在mtDNA中重新构建了无碱性部位或8氧-DG病变的修复。肯定 不认为病变，例如mtDNA中的环丁烷嘧啶二聚体 有效地修复。我们将尝试提高效率 通过使用分子遗传技术进行修复来直接修复酶 例如光解酶或T4核酸内切酶（DENV）到线粒体。