Sequence-targeted nucleosome sliding in vivo by a hybrid Chd1 chromatin remodeler.
Sequence-targeted nucleosome sliding in vivo by a hybrid Chd1 chromatin remodeler.
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DOI：
10.1101/gr.199919.115
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发表时间：
2016-05
期刊：
影响因子：
7
通讯作者：
Bowman GD
中科院分区：
文献类型：
--
作者：
McKnight JN;Tsukiyama T;Bowman GD
依赖于ATP的染色质重构体通过改变核小体的位置和占位来调节染色质的动态。依赖DNA的过程，如复制和转录，依赖染色质来忠实地调节DNA的可及性，但染色质重构体如何在体内实现明确的核小体定位尚不清楚。在这里，我们报告了一种简单的方法，用于定点改变活细胞中的核小体位置。通过将Chd1重构体与酿酒酵母Ume6阻遏子的DNA结合域融合，我们设计出了一种融合重构体，它以一种高度可预测和可重复性的方式选择性地将核小体定位在相邻的Ume6结合基序的顶部。融合重构体对核小体的定位在Ume6敏感基因上重塑了封闭的染色质结构，类似于内源性Isw2重构体。引人注目的是，通过嵌合Chd1-Ume6或内源性Isw2对单个创建者核小体的高精度定位，与内源性染色质重构体合作，移动了相变的染色质阵列。我们的结果证明了通过序列靶向染色质重塑来设计精确的核小体重排的可行性，并为体内内源性染色质重构体的靶向作用和合作提供了洞察力。
ATP-dependent chromatin remodelers regulate chromatin dynamics by modifying nucleosome positions and occupancy. DNA-dependent processes such as replication and transcription rely on chromatin to faithfully regulate DNA accessibility, yet how chromatin remodelers achieve well-defined nucleosome positioning in vivo is poorly understood. Here, we report a simple method for site-specifically altering nucleosome positions in live cells. By fusing the Chd1 remodeler to the DNA binding domain of the Saccharomyces cerevisiae Ume6 repressor, we have engineered a fusion remodeler that selectively positions nucleosomes on top of adjacent Ume6 binding motifs in a highly predictable and reproducible manner. Positioning of nucleosomes by the fusion remodeler recapitulates closed chromatin structure at Ume6-sensitive genes analogous to the endogenous Isw2 remodeler. Strikingly, highly precise positioning of single founder nucleosomes by either chimeric Chd1-Ume6 or endogenous Isw2 shifts phased chromatin arrays in cooperation with endogenous chromatin remodelers. Our results demonstrate feasibility of engineering precise nucleosome rearrangements through sequence-targeted chromatin remodeling and provide insight into targeted action and cooperation of endogenous chromatin remodelers in vivo.