The N-terminus of histone H2B, but not that of histone H3 or its phosphorylation, is essential for chromosome condensation
The N-terminus of histone H2B, but not that of histone H3 or its phosphorylation, is essential for chromosome condensation
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DOI：
10.1093/emboj/20.22.6383
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发表时间：
2001-11-15
期刊：
影响因子：
11.4
通讯作者：
Dimitrov, S
中科院分区：
文献类型：
--
作者：
de la Barre, AE;Angelov, D;Dimitrov, S
我们研究了单个组蛋白N-末端和组蛋白H3磷酸化在染色体凝聚中的作用。核小体，重组与组蛋白八聚体含有不同的重组全长和无尾组蛋白的组合，被用来作为竞争对手的染色体装配在非洲爪蟾卵提取物。与完整的八聚体重组的核小体抑制染色体凝聚有效地作为本地的，而无尾核小体无法影响这一过程。重要的是，向提取物中添加仅含有完整组蛋白H2 B的颗粒强烈干扰染色体形成，而在缺乏H2 B的N-末端尾的颗粒中未观察到这种作用。这表明在竞争性核小体存在下观察到的抑制作用主要是由于该组蛋白的N-末端，因此，其对于染色体浓缩是必需的。核小体中，所有组蛋白，但H3无尾并不妨碍染色体的形成。此外，当用全长H2 A、H2 B和H4以及在可磷酸化的丝氨酸10或丝氨酸28处突变的组蛋白H3重构竞争性核小体颗粒时，它们的抑制效率与天然颗粒的抑制效率相同。因此，H3的尾部，无论是完整的还是磷酸化的，对于染色体浓缩都不重要。一个新的假说，称为“现成的生产标签”，建议解释组蛋白H3磷酸化在细胞分裂过程中的作用。
We have studied the role of individual histone N-termini and the phosphorylation of histone H3 in chromosome condensation. Nucleosomes, reconstituted with histone octamers containing different combinations of recombinant full-length and tailless histones, were used as competitors for chromosome assembly in Xenopus egg extracts. Nucleosomes reconstituted with intact octamers inhibited chromosome condensation as efficiently as the native ones, while tailless nucleosomes were unable to affect this process. Importantly, the addition to the extract of particles containing only intact histone H2B strongly interfered with chromosome formation while such an effect was not observed with particles lacking the N-terminal tail of H2B. This demonstrates that the inhibition effect observed in the presence of competitor nucleosomes is mainly due to the N-terminus of this histone, which, therefore, is essential for chromosome condensation. Nucleosomes in which all histones but H3 were tailless did not impede chromosome formation. In addition, when competitor nucleosome particles were reconstituted with full-length H2A, H2B and H4 and histone H3 mutated at the phosphorylable serine 10 or serine 28, their inhibiting efficiency was identical to that of the native particles. Hence, the tail of H3, whether intact or phosphorylated, is not important for chromosome condensation. A novel hypothesis, termed 'the ready production label' was suggested to explain the role of histone H3 phosphorylation during cell division.