Kinetics of core histones in living human cells: little exchange of H3 and H4 and some rapid exchange of H2B.
Kinetics of core histones in living human cells: little exchange of H3 and H4 and some rapid exchange of H2B.
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DOI：
10.1083/jcb.153.7.1341
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发表时间：
2001-06-25
期刊：
影响因子：
--
通讯作者：
Cook PR
中科院分区：
文献类型：
--
作者：
Kimura H;Cook PR
组蛋白H_2A和H_2B构成与H_3和H_4相同的核小体结构的一部分。建立了稳定表达绿色荧光蛋白(GFP)标记的组蛋白H_2B、H_3和H_4的HeLa细胞系，并将标记的分子组装成核小体。虽然H_2B-GFP像DNA一样分布，但H3-GFP和H4-GFP在间期集中在常染色质中，在有丝分裂染色体中集中在R带中。这些差异可能是由于标记的组蛋白的不受调控的生产和交换的差异造成的。在单细胞和异核体中，光漂白显示H_2B-GFP比H_3-GFP和H_4-GFP交换更快。约3%的H2B在几分钟内交换，而∼40%的交换速度很慢(t1/2∼130min)。快速交换部分在5，6-二氯-1-β-d-呋喃核糖基苯并咪唑中消失，可能代表转录活性染色质中的H_2B。缓慢交换的部分可能与活性单位周围的染色质结构域有关。当DNA复制时，H3-GFP和H4-GFP组装成染色质，然后>；80%永久结合。这些结果表明，核小体的内核非常稳定，而活跃的核小体表面的H_2B不断交换。
Histones H2A and H2B form part of the same nucleosomal structure as H3 and H4. Stable HeLa cell lines expressing histones H2B, H3, and H4 tagged with green fluorescent protein (GFP) were established; the tagged molecules were assembled into nucleosomes. Although H2B-GFP was distributed like DNA, H3-GFP and H4-GFP were concentrated in euchromatin during interphase and in R-bands in mitotic chromosomes. These differences probably result from an unregulated production of tagged histones and differences in exchange. In both single cells and heterokaryons, photobleaching revealed that H2B-GFP exchanged more rapidly than H3-GFP and H4-GFP. About 3% of H2B exchanged within minutes, whereas ∼40% did so slowly (t 1/2 ∼ 130 min). The rapidly exchanging fraction disappeared in 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole and so may represent H2B in transcriptionally active chromatin. The slowly exchanging fraction was probably associated with chromatin domains surrounding active units. H3-GFP and H4-GFP were assembled into chromatin when DNA was replicated, and then >80% remained bound permanently. These results reveal that the inner core of the nucleosome is very stable, whereas H2B on the surface of active nucleosomes exchanges continually.
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影响因子：
16
作者：
Bednar, J;Studitsky, VM;Woodcock, CL
通讯作者：
Woodcock, CL
影响因子：
3.7
作者：
IZUMI, M;MIYAZAWA, H;HANAOKA, F
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影响因子：
2.9
作者：
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14.9
作者：
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影响因子：
7.8
作者：
Kruhlak, M J;Lever, M A;Fischle, W;Verdin, E;Bazett-Jones, D P;Hendzel, M J
通讯作者：
Hendzel, M J