Live-cell single particle imaging reveals the role of RNA polymerase II in histone H2A.Z eviction
Live-cell single particle imaging reveals the role of RNA polymerase II in histone H2A.Z eviction
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DOI：
10.7554/elife.55667
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发表时间：
2020-04-27
期刊：
影响因子：
7.7
通讯作者：
Wu, Carl
中科院分区：
文献类型：
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作者：
Ranjan, Anand;Nguyen, Vu Q.;Wu, Carl
H2A.Z组蛋白变体是允许染色质的全基因组标志，在所有真核生物中在转录起始位点附近富集。H2A.Z通过SWR 1染色质重塑剂沉积，并通过不清楚的机制被驱逐。我们在单分子分辨率下跟踪活酵母中的H2A.Z，发现H2A.Z驱逐依赖于RNA聚合酶II（Pol II）和Kin 28/Cdk 7激酶，其磷酸化最大Pol II亚基Rpb 1的羧基末端结构域上的七肽重复的丝氨酸5。这些发现将H2A.Z驱逐与Pol II的转录起始、启动子逃逸和早期延伸活动联系起来。由于Pol II通过+1核小体的全基因组传递将强制H2A.Z周转，我们提出酵母启动子处的全局转录负责驱逐H2A.Z。酵母Pol II的这种使用表明了将真核转录与H2A.Z表观遗传信号的擦除偶联的一般机制。
The H2A.Z histone variant, a genome-wide hallmark of permissive chromatin, is enriched near transcription start sites in all eukaryotes. H2A.Z is deposited by the SWR1 chromatin remodeler and evicted by unclear mechanisms. We tracked H2A.Z in living yeast at single-molecule resolution, and found that H2A.Z eviction is dependent on RNA Polymerase II (Pol II) and the Kin28/Cdk7 kinase, which phosphorylates Serine 5 of heptapeptide repeats on the carboxyterminal domain of the largest Pol II subunit Rpb1. These findings link H2A.Z eviction to transcription initiation, promoter escape and early elongation activities of Pol II. Because passage of Pol II through +1 nucleosomes genome-wide would obligate H2A.Z turnover, we propose that global transcription at yeast promoters is responsible for eviction of H2A.Z. Such usage of yeast Pol II suggests a general mechanism coupling eukaryotic transcription to erasure of the H2A.Z epigenetic signal.