Repair of oxidative DNA damage in Mammalian cells

修复哺乳动物细胞中的氧化DNA损伤

• 批准号: 13480162
• 负责人: YASUI Akira
• 金额: $ 9.28万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13480162/
• 关键词: DNA damage; DNA repair; base excision repair; oxidative DNA damage; glycosylase; 活性酸素; 発がん; 老化; 単鎖切断; ポリADPリボシル化; XRCC1; UVDE; チミングリコール; ノックアウトマウス; ミトコンドリア

Endonuclease III, encoded by nth in Escherichia coli, removes thymine glycols, a toxic oxidative DNA lesion. To determine the biological significance of this repair in mammals, we established a mouse mutated in mNth1, a homologue of nth, by gene targeting. The homozygous mNth1 mutant mouse showed no detectable phenotypic abnormality so far analyzed. Embryonic cells with or without wild-type mNth1 showed no difference in sensitivity to menadione or hydrogen peroxide. Thymine glycols produced in the mutant mouse liver DNA by X-ray irradiation disappeared with time, though more slowly than in wild-type mouse. In extracts from mutant mouse liver, we found, instead of mNTH1 activity, at least two novel DNA glycosylase activities against thymine glycols. One activity is significantly higher in the mutant than in wild-type mouse in mitochondria, while the other is another nuclear glycosylase, for thymine glycols. These results underscore the importance of base excision repair of thymine glycols both in the nuclei and in the mitochondria in mammals.

内切核酸酶III，由大肠杆菌中的nth编码，去除胸腺嘧啶二醇，一种有毒的氧化DNA损伤。为了确定这种修复在哺乳动物中的生物学意义，我们通过基因靶向建立了mNth1突变的小鼠，mNth1是nth的同源物。纯合子mNth1突变小鼠未显示出可检测到的表型异常。有或没有野生型mNth1的胚胎细胞对甲萘醌或过氧化氢的敏感性没有差异。胸腺嘧啶二醇产生的突变小鼠肝脏DNA的X射线照射消失，随着时间的推移，虽然比野生型小鼠更慢。在突变小鼠肝脏提取物中，我们发现，而不是mNTH1活性，至少有两个新的DNA糖基化酶活性对胸腺嘧啶二醇。一种活性在突变体中比野生型小鼠的线粒体中显著更高，而另一种是另一种核糖基化酶，用于胸腺嘧啶二醇。这些结果强调了哺乳动物细胞核和线粒体中胸腺嘧啶二醇的碱基切除修复的重要性。

项目成果

Li Lom et al.: "Functional and physical Interactions between ERCC1 and MSH_2 complexes"DNA Repair. 3. 135-145 (2004)

Li Lom 等人：“ERCC1 和 MSH_2 复合物之间的功能和物理相互作用”DNA 修复。

Okano, S. 他: "Spatial and temporal assembly of the proteins involved in repair of single-strand breaks in human cells"Mol. Cell. Biol. (in press). (2003)

Okano, S. 等人：“参与人类细胞单链断裂修复的蛋白质的空间和时间组装”，Mol Cell。

Okano S.et al.: "Spatial and temporal assembly of the proteins involved in repair"Mol.Cell.Biol.. 23. 3974-3981 (2003)

Okano S.等人：“参与修复的蛋白质的空间和时间组装”Mol.Cell.Biol.. 23. 3974-3981 (2003)

Yoo, YH., Yasui, A. 他: "Cyclobutane pyrimidine dimers are responsible for the vast majority of mutations induced by UVB irradiation in mammalian cells"J. Biol. Chem.. 276. 44688-44694 (2001)

Yoo, YH., Yasui, A. 等人：“环丁烷嘧啶二聚体是造成哺乳动物细胞中 UVB 照射诱导的绝大多数突变的原因”J. Biol. 276. 44688-44694 (2001)

Takahashi H, et al.: "Mouse dexamethasone-induced RAS protein 1 is expressed"Mol.Brain Res.. 110. 1-6 (2003)

Takahashi H，等：“小鼠地塞米松诱导的 RAS 蛋白 1 表达”Mol.Brain Res.. 110. 1-6 (2003)