A novel 6C assay uncovers Polycomb-mediated higher order chromatin conformations
A novel 6C assay uncovers Polycomb-mediated higher order chromatin conformations
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DOI：
10.1101/gr.073452.107
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发表时间：
2008-07-01
期刊：
影响因子：
7
通讯作者：
Baylin, Stephen B.
中科院分区：
文献类型：
--
作者：
Tiwari, Vijay K.;Cope, Leslie;Baylin, Stephen B.
我们描述了染色质环化测定的新修饰“6C”的构建，该修饰允许定义可能介导长程染色质相互作用的特定蛋白质。该方法将先前定义的标准循环方法与免疫沉淀步骤相结合，以研究特定蛋白质的参与。该方法的功效通过使用 Polycomb 组 (PcG) 蛋白、Zeste 增强剂 (EZH2) 来证明，作为如何使用我们的检测的示例。 EZH2 作为 PcG 复合体 PRC2 的一种蛋白，通过沉积抑制标记、组蛋白 H3、赖氨酸 27、三甲基化 (H3K27me3)，在表观遗传记忆的传播中发挥重要作用。使用我们新的 6C 测定，我们展示了 EZH2 如何作为长程染色体内和染色体间相互作用的直接介导者，可以通过促进遥远染色质区域之间的物理接近性来调节多个基因的转录下调，从而靶向 PcG 机器内的位点。
We describe construction of a novel modification, "6C," of chromatin looping assays that allows specific proteins that may mediate long-range chromatin interactions to be defined. This approach combines the standard looping approaches previously defined with an immunoprecipitation step to investigate involvement of the specific protein. The efficacy of this approach is demonstrated by using a Polycomb group (PcG) protein, Enhancer of Zeste (EZH2), as an example of how our assay might be used. EZH2, as a protein of the PcG complex, PRC2, has an important role in the propagation of epigenetic memory through deposition of the repressive mark, histone H3, lysine 27, tri-methylation (H3K27me3). Using our new 6C assay, we show how EZH2 is a direct mediator of long-range intraand interchromosomal interactions that can regulate transcriptional down-regulation of multiple genes by facilitating physical proximities between distant chromatin regions, thus targeting sites within to PcG machinery.