MITOCHONDRIAL DNA DAMAGE AND REPAIR

线粒体 DNA 损伤与修复

• 批准号: 6443874
• 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: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2002-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6443874
• 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。基本损耗， 氧化损伤和与致癌化合物的反应，如 苯并(A)芘和黄曲霉毒素的发生速度被认为等于或 大于相应的核DNA损伤率。 线粒体能够修复某些类型的DNA损伤，例如 部位和氧化损伤(例如，8-oxo-DG)，但可能不是其他。 对DNA修复的酶学研究知之甚少。 线粒体。通过DNA加合物或尝试修复进行的复制可能 导致发现的点突变和缺失的发生率 越来越多的人类疾病。这些疾病各有不同。 与罕见的神经肌肉疾病相关的突变与 缩写MELAS、MERRF和NARP是在Kearns观察到的大片段缺失 塞尔综合征。最近的研究发现线粒体DNA与 损害和11型糖尿病、帕金森氏症和衰老，尽管更多 需要研究来确定线粒体DNA损伤在病因学中的作用 这些条件。我们建议调查 由我们制备的DNA模板中的特定定位损伤 该项目的合作者通过纯化的DNA复制 线粒体DNA聚合酶伽马。这些研究将使用模板 含有碱性中心、8-氧代-DG、氨基荧和苯并(A)芘 加合物。我们还将寻找可能有助于 脱氧核糖核酸聚合酶-伽马的转位合成。我们建议进行实验 确定参与线粒体DNA修复的酶的特征，并尝试 线粒体DNA基本部位或8-oxo-DG损伤的重建修复。一定的 损伤，如线粒体DNA中的环丁烷嘧啶二聚体不被认为 要得到有效的维修。我们将努力提高效率。 利用分子遗传技术指导修复酶的修复 如光解酶或T4核酸内切酶(DENV)对线粒体的作用。