MECHANISMS OF CHEMICAL MUTAGENESIS AND REPAIR OF DNA ADDUCTS

DNA加合物的化学诱变和修复机制

• 批准号: 6106124
• 负责人: SHINYA SHIBUTANI
• 金额: $ 19.84万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6106124
• 关键词: DNA damage; DNA repair; Escherichia coli; acetylaminofluorene; adduct; benzopyrenes; deoxyadenosines; environmental toxicology; enzyme activity; enzyme structure; gene mutation; guanine analog; mutagens; nucleic acid sequence; protein purification; protein structure; site directed mutagenesis

The long-range goals of this research are two-fold; to establish the mutagenic potential of selected environmental mutagens and to explore the molecular basis for recognition and repaired of damaged DNA. Excellent progress has been made during the past project period. Quantitative methods have been developed that allowed us to establish in vitro and in vivo the mutagenic profiles of defined DNA adducts. Fundamental principles have emerged that will facilitate analyses of mutational spectra produced by environmental mutagens. For example, using site-specific techniques, we can predict nucleotide sequence contexts of mutational hot spots. We also discovered that DNA polymerases differ strikingly from one another in their miscoding potential with respect to certain DNA adducts. We also describe a new pathway for repair of oxidative DNA damage in E. coli. In the next project period, we will seek to determine the mutagenic potential in vitro and in vivo for PhIP and 8-aminoguanine, a modified DNA base which accumulates in the liver of animals treated with 2- nitropropane. We will use our experimental systems to explore molecular mechanisms of base substitutions and deletion mutagenesis for abasic sites, aminofluorene adducts and four stereoisomers derived from benzo(a)pyrene. Part of this project is devoted to studies of DNA repair enzymes; we propose to isolate and purify homologs of Fpg protein and MutY protein from mammalian sources. Finally, we will study the interaction of a single zinc finger derived from Fpg protein with damaged DNA.

这项研究的远距离目标是两个方面。建立 选定环境诱变剂的诱变潜力，并探索 识别识别并修复受损DNA的分子基础。 在过去的项目期间，已经取得了良好的进步。 已经开发了定量方法，使我们能够在 体外和体内定义的DNA加合物的诱变谱。 已经出现了基本原则，这些原则将有助于分析 由环境诱变剂产生的突变光谱。例如，使用 网站特异性技术，我们可以预测的核苷酸序列上下文 突变热点。我们还发现DNA聚合酶不同 彼此之间的误导潜力相对于 某些DNA加合物。我们还描述了修复的新途径 大肠杆菌中的氧化DNA损伤。 在下一个项目时期，我们将寻求确定诱变 在体外和体内的潜在pHIP和8-氨基甘氨酸，这是一种改良的 DNA碱在用2-处理的动物的肝脏中积聚 硝酸丙烷。我们将使用我们的实验系统探索分子 基础取代的机制和无碱的缺失诱变 位置，氨基氟加合物和四个立体异构体。 苯并（a）pyrene。该项目的一部分致力于研究DNA修复 酶；我们建议隔离和纯化FPG蛋白的同源物和 来自哺乳动物来源的muty蛋白。最后，我们将研究 源自FPG蛋白的单个锌指的相互作用与受损 脱氧核糖核酸。