Genomic Nucleosome Organization Reconstituted with Pure Proteins.
Genomic Nucleosome Organization Reconstituted with Pure Proteins.
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DOI：
10.1016/j.cell.2016.09.045
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发表时间：
2016-10-20
期刊：
影响因子：
64.5
通讯作者：
Korber P
中科院分区：
文献类型：
--
作者：
Krietenstein N;Wal M;Watanabe S;Park B;Peterson CL;Pugh BF;Korber P
染色质重塑剂通过在启动子周围组织核小体来调节基因，但它们各自的贡献被因子冗余和间接效应的复杂体内环境所混淆。用纯化的蛋白质对启动子核小体组织进行全基因组重建解决了这个问题，因此是一个关键目标。在这里，我们使用纯化的组分重建核小体结构的四个阶段：酵母基因组 DNA、组蛋白、序列特异性 Abf1/Reb1 和重塑剂 RSC、ISW2、INO80 和 ISW1a。我们确定了体内观察验证的直接、具体和充分的贡献。首先，RSC 通过将聚 (dA:dT) 翻译为定向核小体去除来清除启动子。其次，部分冗余被概括为单独的 INO80 或 Abf1/Reb1 位点的 ISW2，位置 +1 核小体。第三，INO80 和 ISW2 各自对齐下游核小体阵列。第四，ISW1a 将间距收紧到规范的重复长度。这样一组最小的规则和蛋白质建立了核心机制，通过该机制，启动子染色质结构通过冗余和专门化的混合而产生。
Chromatin remodelers regulate genes by organizing nucleosomes around promoters, but their individual contributions are obfuscated by the complex in vivo milieu of factor redundancy and indirect effects. Genome-wide reconstitution of promoter nucleosome organization with purified proteins resolves this problem and is therefore a critical goal. Here we reconstitute four stages of nucleosome architecture using purified components: Yeast genomic DNA, histones, sequence-specific Abf1/Reb1, and remodelers RSC, ISW2, INO80, and ISW1a. We identify direct, specific and sufficient contributions that in vivo observations validate. First, RSC clears promoters by translating poly(dA:dT) into directional nucleosome removal. Second, partial redundancy is recapitulated where INO80 alone, or ISW2 at Abf1/Reb1sites, positions +1 nucleosomes. Third, INO80 and ISW2 each align downstream nucleosomal arrays. Fourth, ISW1a tightens the spacing to canonical repeat lengths. Such a minimal set of rules and proteins establishes core mechanisms by which promoter chromatin architecture arises through a blend of redundancy and specialization.