在H19/Igf2位点中,CTCF调解了对甲基化敏感的增强剂阻断活性
A T Hark1, C J Schoenherr, D J Katz
1Howard Hughes Medical Institute and Department of Molecular Biology, Princeton University, New Jersey 08544, USA.
Nature
|June 6, 2000
概括
在H19附近的印记控制区域作为边界,阻止基因相互作用. 对该区域的CTCF结合防止了基因沉默,但甲基化破坏了这一边界功能.
科学领域:
- 遗传学 是一个遗传学.
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 基因组印记是一种基因组印记.
背景情况:
- 胰岛素样生长因子2 (Igf2) 和H19基因受到基因组印记的影响,母系和父系等位基因的差异性沉默.
- 这种印记是由上游印记控制区域 (ICR) 调节的,该区域对等位基因特异性基因表达至关重要.
研究的目的:
- 研究H19 ICR在调节Igf2和H19基因表达中的功能.
- 确定DNA甲基化和CTCF结合在ICR介导基因调节中的作用.
主要方法:
- 使用了转基因小鼠和组织培养模型.
- 评估了H19 ICR的增强剂阻断活性.
- 研究了CTCF与ICR的结合以及DNA甲基化对结合和功能的影响.
主要成果:
- 证明来自老鼠和人类的非甲基化H19 ICR具有增强剂阻断活性.
- 在ICR中确定了CTCF结合点,这对于这种增强器阻断功能至关重要.
- 表明DNA甲基化消除了CTCF结合,从而消除了增强剂阻断活性.
结论:
- 非甲基化ICR作为受调的染色质边界,通过CTCF结合进行介导.
- DNA甲基化破坏了CTCF结合,导致边界功能的丧失,并使父亲的Igf2表达.
- 这项研究提供了第一个涉及基因组印记的受调节脊椎动物染色质边界的例子.
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