Heat Stress Affects H3K9me3 Level at Human Alpha Satellite DNA Repeats
Heat Stress Affects H3K9me3 Level at Human Alpha Satellite DNA Repeats
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DOI：
10.3390/genes11060663
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发表时间：
2020-06-01
期刊：
影响因子：
3.5
通讯作者：
Ugarkoyie, Durdica
中科院分区：
文献类型：
--
作者：
Feliciello, Isidoro;Sermek, Antonio;Ugarkoyie, Durdica
卫星DNA是串联重复序列，优先组装成组成型异染色质内的大阵列，并且它们的转录通常被胁迫条件，特别是热胁迫激活。然而，测序基因组的生物信息学分析揭示了在常染色质内基因附近分散的卫星DNA的单重复或短阵列。在这里，我们分析转录的一个主要的人类α卫星DNA热应激后，并遵循动态的“沉默”H3 K9 me 3和“活跃”H3 K4 me 2/3组蛋白标记在分散的常染色质和串联排列的异染色质α重复。结果显示，在热应激时，H3 K9 me 3在α重复处富集，这与α卫星DNA转录激活的动力学相关，而未检测到H3 K4 me 2/3水平的变化。检测到H3 K9 me 3从常染色质α重复序列的插入位点扩展至1-2 kb，揭示了α重复序列作为局部染色质结构的调节剂。此外，在内含子内含有α重复序列的基因以及最接近基因间α重复序列的基因的表达在热应激时下调。进一步的研究是必要的，以揭示H3 K9 me 3富集的α重复序列，特别是那些位于内含子内，其相关基因的沉默的可能贡献。
Satellite DNAs are tandemly repeated sequences preferentially assembled into large arrays within constitutive heterochromatin and their transcription is often activated by stress conditions, particularly by heat stress. Bioinformatic analyses of sequenced genomes however reveal single repeats or short arrays of satellite DNAs dispersed in the vicinity of genes within euchromatin. Here, we analyze transcription of a major human alpha satellite DNA upon heat stress and follow the dynamics of "silent" H3K9me3 and "active" H3K4me2/3 histone marks at dispersed euchromatic and tandemly arranged heterochromatic alpha repeats. The results show H3K9me3 enrichment at alpha repeats upon heat stress, which correlates with the dynamics of alpha satellite DNA transcription activation, while no change in H3K4me2/3 level is detected. Spreading of H3K9me3 up to 1-2 kb from the insertion sites of the euchromatic alpha repeats is detected, revealing the alpha repeats as modulators of local chromatin structure. In addition, expression of genes containing alpha repeats within introns as well as of genes closest to the intergenic alpha repeats is downregulated upon heat stress. Further studies are necessary to reveal the possible contribution of H3K9me3 enriched alpha repeats, in particular those located within introns, to the silencing of their associated genes.