Loading of Arabidopsis centromeric histone CENH3 occurs mainly during G2 and requires the presence of the histone fold domain
Loading of Arabidopsis centromeric histone CENH3 occurs mainly during G2 and requires the presence of the histone fold domain
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DOI：
10.1105/tpc.106.043174
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发表时间：
2006-10-01
期刊：
影响因子：
11.6
通讯作者：
Schubert, Ingo
中科院分区：
文献类型：
--
作者：
Lermontova, Inna;Schubert, Veit;Schubert, Ingo
着丝粒组蛋白H3（CENH3）在所有真核生物中的活性着丝粒的核小体内取代组蛋白H3。需要CENH 3沉积在着丝粒处以组装动粒，动粒是负责在核分裂期间正确的染色体分离的保守蛋白质的复合物。常规核小体的组蛋白在S期复制期间被加载，而CENH 3沉积在酵母、人和果蝇细胞中偏离这种模式。关于CENH3何时以及如何靶向着丝粒位点知之甚少。因此，我们确定了重组增强型黄色荧光蛋白（EYFP）-CENH 3在转基因拟南芥细胞有丝分裂根和内多倍体叶核中的位置和数量。我们的数据表明A的显著负载。在G2期（分裂成姐妹着丝粒之前），而不是在细胞周期的S或M期。CENH 3的C-末端部分的组蛋白折叠结构域足以靶向A.拟南芥着丝粒a. EYFP-CENH3可以识别并靶向拟南芥的三个不同的着丝粒重复，但不能识别蚕豆的着丝粒。
The centromeric histone H3 ( CENH3) substitutes histone H3 within the nucleosomes of active centromeres in all eukaryotes. CENH3 deposition at centromeres is needed to assemble the kinetochore, a complex of conserved proteins responsible for correct chromosome segregation during nuclear division. Histones of regular nucleosomes are loaded during replication in S phase, while CENH3 deposition deviates from this pattern in yeast, human, and Drosophila melanogaster cells. Little is known about when and how CENH3 targets centromeric loci. Therefore, we determined the location and quantity of recombinant enhanced yellow fluorescent protein ( EYFP)- CENH3 in mitotic root and endopolyploid leaf nuclei of transgenic Arabidopsis thaliana cells. Our data indicate significant loading of A. thaliana CENH3 during G2 ( before splitting into sister kinetochores) rather than during the S or M phase of the cell cycle. The histone fold domain of the C- terminal part of CENH3 is sufficient to target A. thaliana centromeres. A. thaliana EYFP- CENH3 can recognize and target three different centromeric repeats of Arabidopsis lyrata but not field bean ( Vicia faba) centromeres.