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CpG岛屿通过CpG结合蛋白Cfp1影响染色质结构
John P Thomson1, Peter J Skene, Jim Selfridge
1Wellcome Trust Centre for Cell Biology, Michael Swann Building, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, UK.
Nature
|April 16, 2010
概括
CpG岛屿 (CGI) 是关键的基因组区域. 这项研究确定Cfp1是一种蛋白质,它结合非甲基化CpG,影响染色质结构和H3K4me3水平,从而调节基因表达.
科学领域:
- 基因组学就是基因组学.
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 分子生物学分子生物学
背景情况:
- CpG岛屿 (CGI) 是富含GC的基因组区域,具有高CpG二核酸密度.
- 大多数人类基因促进体都在CGI中,这些基因通常未甲基化,并以H3K4me3.3标记.
- 未甲基化CGI在染色质结构和转录中的功能作用尚不清楚.
研究的目的:
- 调查非甲基化CpG群岛的功能意义.
- 为了识别特定与非甲基化CpG位点结合的蛋白质.
- 了解CpG结合蛋白在建立染色质修饰中的作用.
主要方法:
- 对所有CGI共同的蛋白质的生物信息搜索.
- 用非甲基化CpG进行Cfp1的体外结合试验.
- 染色体免疫沉 (ChIP) 和高通量测序.
- 整合到小鼠基因组中的人工CpG集群的分析.
主要成果:
- 鉴定出Cfp1是一种高含量CGI的蛋白质,在体外和体内都能选择性地结合非甲基化CpG.
- 结合Cfp1与未甲基化CGI和小鼠大脑中的H3K4me3位点有很强的相关性.
- Cfp1的耗尽降低了CGI中的H3K4me3水平,这表明它在招募H3K4甲基转移酶中的作用.
- 人工CpG集群招募了Cfp1并诱导了H3K4me3,即使没有促进者.
结论:
- 非甲基化CpG群岛在指导局部染色体修饰状态方面发挥着至关重要的作用.
- Cfp1是一个关键的调解器,将非甲基化CGI与H3K4三甲基化联系起来.
- 这些发现揭示了CGI影响染色体结构和潜在的基因调节的机制.
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