A genome-wide role for CHD remodelling factors and Nap1 in nucleosome disassembly
A genome-wide role for CHD remodelling factors and Nap1 in nucleosome disassembly
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DOI：
10.1038/sj.emboj.7601728
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发表时间：
2007-06-20
期刊：
影响因子：
11.4
通讯作者：
Ekwall, Karl
中科院分区：
文献类型：
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作者：
Walfridsson, Julian;Khorosjutina, Olga;Ekwall, Karl
染色质重塑因子和组蛋白分子伴侣先前被证明在体外协同影响核小体组装和拆卸过程。在这里，我们表明，裂殖酵母粟酒裂殖酵母CHD重塑，Hrp1和Hrp3旁系同源物物理相互作用的组蛋白伴侣Nap1。Hrp1、Hrp3和Nap1占有率的全基因组分析与核小体密度测量相结合揭示了CHD因子和Nap1共定位于特别是启动子区域，在那里它们去除转录起始位点附近的核小体。Hrp1和Hrp3还调节编码区的核小体密度，在那里它们具有刺激转录的冗余作用。以前，DNA复制依赖性和非依赖性核小体解体过程已被描述。我们发现，核小体密度增加的hrp1突变体在DNA复制的情况下。最后，在hrp1，hrp3和nap1突变体中核小体密度增加的区域也显示出HDAC和HAT突变体中核小体密度和组蛋白修饰的变化。因此，这项研究揭示了CHD重塑和Nap1在启动子和编码区的核小体解体中的重要体内作用，这与组蛋白乙酰化的变化有关。
Chromatin remodelling factors and histone chaperones were previously shown to cooperatively affect nucleosome assembly and disassembly processes in vitro. Here, we show that Schizosaccharomyces pombe CHD remodellers, the Hrp1 and Hrp3 paralogs physically interact with the histone chaperone Nap1. Genome- wide analysis of Hrp1, Hrp3 and Nap1 occupancy, combined with nucleosome density measurements revealed that the CHD factors and Nap1 colocalized in particular to promoter regions where they remove nucleosomes near the transcriptional start site. Hrp1 and Hrp3 also regulate nucleosome density in coding regions, where they have redundant roles to stimulate transcription. Previously, DNA replication-dependent and -independent nucleosome disassembly processes have been described. We found that nucleosome density increased in the hrp1 mutant in the absence of DNA replication. Finally, regions where nucleosome density increased in hrp1, hrp3 and nap1 mutants also showed nucleosome density and histone modification changes in HDAC and HAT mutants. Thus, this study revealed an important in vivo role for CHD remodellers and Nap1 in nucleosome disassembly at promoters and coding regions, which are linked to changes in histone acetylation.