Murata-Kamiya N, Kamiya H, Kaji H, Kasai H
Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan.
Biochem Biophys Res Commun. 1998 Jul 20;248(2):412-7. doi: 10.1006/bbrc.1998.8973.
To investigate the influence of nucleotide excision repair (NER) on glyoxal-induced mutations, we treated wild-type and NER-deficient (uvrC) Escherichia coli strains with glyoxal, and analyzed mutations in the chromosomal lacI gene. In both strains, the cell death and the mutation frequency increased according to the dose of glyoxal added to the culture medium, and cell death was induced to a similar level in both strains. Interestingly, the frequency of glyoxal-induced mutations in the wild-type strain was higher than that in the uvrC strain. Particularly, the frequency of base-pair substitutions was 4.7-fold higher in the wild-type strain. In the wild-type strain, G:C-->T:A transversions were predominant, followed by G:C-->A:T and A:T-->T:A mutations. In the uvrC strain, G:C-->A:T transitions were predominant, followed by G:C-->T:A transversions. All the base-pair substitutions except for G:C-->A:T transitions were >4-fold higher in the wild-type strain than in the uvrC strain. These results suggest that NER may be involved in the fixation of glyoxal-induced base-pair substitutions.
为了研究核苷酸切除修复（NER）对乙二醛诱导突变的影响，我们用乙二醛处理野生型和NER缺陷型（uvrC）大肠杆菌菌株，并分析染色体lacI基因中的突变。在两种菌株中，细胞死亡和突变频率均随添加到培养基中的乙二醛剂量增加而升高，且两种菌株中的细胞死亡诱导水平相似。有趣的是，野生型菌株中乙二醛诱导的突变频率高于uvrC菌株。特别是，野生型菌株中碱基对替换频率高4.7倍。在野生型菌株中，G:C→T:A颠换占主导，其次是G:C→A:T和A:T→T:A突变。在uvrC菌株中，G:C→A:T转换占主导，其次是G:C→T:A颠换。除G:C→A:T转换外，野生型菌株中所有碱基对替换均比uvrC菌株高4倍以上。这些结果表明，NER可能参与乙二醛诱导的碱基对替换的固定。
