The impact of the HIRA histone chaperone upon global nucleosome architecture.
The impact of the HIRA histone chaperone upon global nucleosome architecture.
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DOI：
10.4161/15384101.2014.967123
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Whitehall SK
中科院分区：
文献类型：
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作者：
Gal C;Moore KM;Paszkiewicz K;Kent NA;Whitehall SK
HIRA 是一种进化上保守的组蛋白伴侣，可介导复制独立的核小体组装，对细胞周期进展、发育和衰老等多种过程很重要。在这里，我们使用染色质测序方法来确定 HIRA 对粟酒裂殖酵母核小体组织的全基因组贡献。缺乏 HIRA 的细胞在基因序列上的核小体占有率整体减少，这与 HIRA 在延长 RNA 聚合酶 II 背后的染色质重组中的作用一致。此外，我们发现在其目标启动子处，HIRA 通常保持完全占据 -1 核小体。 HIRA 不影响复制起点或 rDNA 重复中的整体染色质结构，但对于基因组沉默区域中的核小体占据是必需的。与位于着丝粒的异染色质 (dg-dh) 重复相关的核小体组织因 HIRA 功能的丧失而受到干扰，此外 HIRA 是 Tf2 LTR 反转录转座子正常核小体占据所必需的。总的来说，我们的数据表明 HIRA 在维持常染色质和异染色质位点的核小体结构中发挥着重要作用。
HIRA is an evolutionarily conserved histone chaperone that mediates replication-independent nucleosome assembly and is important for a variety of processes such as cell cycle progression, development, and senescence. Here we have used a chromatin sequencing approach to determine the genome-wide contribution of HIRA to nucleosome organization in Schizosaccharomyces pombe. Cells lacking HIRA experience a global reduction in nucleosome occupancy at gene sequences, consistent with the proposed role for HIRA in chromatin reassembly behind elongating RNA polymerase II. In addition, we find that at its target promoters, HIRA commonly maintains the full occupancy of the −1 nucleosome. HIRA does not affect global chromatin structure at replication origins or in rDNA repeats but is required for nucleosome occupancy in silent regions of the genome. Nucleosome organization associated with the heterochromatic (dg-dh) repeats located at the centromere is perturbed by loss of HIRA function and furthermore HIRA is required for normal nucleosome occupancy at Tf2 LTR retrotransposons. Overall, our data indicate that HIRA plays an important role in maintaining nucleosome architecture at both euchromatic and heterochromatic loci.