通过DNA甲基转移酶的高频变异发生
J C Shen1, W M Rideout, P A Jones
1Department of Biochemistry and Molecular Biology, Kenneth Norris, Jr., Comprehensive Cancer Center, University of Southern California, School of Medicine, Los Angeles 90033.
Cell
|December 24, 1992
概括
甲基酶诱导DNA中的C到U突变. 这种酶是这种酶.
科学领域:
- 分子生物学分子生物学
- 酶学 是一种酶学.
- 遗传学 是一个遗传学.
背景情况:
- DNA甲基化对于基因调节至关重要.
- DNA (cytosine-5) - 甲基转移酶 (DNMTs) 是催化DNA甲基化的酶.
- HpaII甲基酶 (M. HpaII) 是一种能够识别CCGG序列的DNMT.
研究的目的:
- 为了研究HPAII甲基酶的突变性潜力.
- 探索M. HpaII诱导的突变的机制.
- 确定S-adenosylmethionine (SAM) 在M. HpaII活动中的作用.
主要方法:
- 在体外与M. HpaII进行突变pSV2-neo等离子体的化.
- 改性塑转化为缺乏 uracil-DNA glycosylase 的细菌.
- 在不同SAM度下进行突变频率分析.
主要成果:
- M. HpaII直接诱导了双链DNA中高频率的C到U过渡突变.
- 在缺乏 uracil-DNA glycosylase 的细菌中观察到逆转率增加了 10^4 倍.
- 突变频率对SAM度高度敏感,在300nm以上下降.
结论:
- M. HpaII可以通过诱导C到U的转换来作为一种变异原体.
- 由M. HpaII进行的酶去胺可能会导致CpG部位的突变热点.
- 这些发现支持甲基转移酶和细胞因子之间的共价复合体形成模型.
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