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。碱基损失， 氧化损伤以及与致癌化合物的反应，例如 苯并(a)芘和黄曲霉毒素的发生率被认为等于或 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，例如脱碱基损伤 位点和氧化损伤（例如 8-oxo-dG），但可能不是其他。 关于DNA修复的酶学知之甚​​少 线粒体。通过 DNA 加合物进行复制或尝试修复可能 导致观察到的点突变和缺失的发生率 越来越多的人类疾病。这些疾病的范围从 与罕见神经肌肉疾病相关的突变 MELAS、MERRF 和 NARP 的缩写，表示卡恩斯中观察到的大量删除 塞尔综合症。最近的研究发现 mtDNA 之间存在相关性 损伤和 1​​1 型糖尿病、帕金森病和衰老，尽管更多 需要研究确定 mtDNA 损伤在病因学中的作用 这些条件。我们建议调查以下影响 我们制备的 DNA 模板中的特定局部损伤 该项目的合作者通过纯化的DNA复制 线粒体 DNA 聚合酶 γ。这些研究将采用模板 含有脱碱基位点、8-oxo-dG、氨基芴和苯并(a)芘 加合物。我们还将寻找可能促进的辅助因素 DNA聚合酶γ的跨病灶合成。我们提出实验 表征参与 mtDNA 修复的酶并尝试 重建 mtDNA 中脱碱基位点或 8-oxo-dG 损伤的修复。肯定 病变，例如 mtDNA 中的环丁烷嘧啶二聚体，不被认为 才能得到有效修复。我们将努力提高效率 利用分子遗传技术指导修复酶进行修复 例如线粒体的光裂解酶或 T4 核酸内切酶 (denV)。