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.

这项研究的长期目标是双重的；建立