VPS72/YL1-Mediated H2A.Z Deposition Is Required for Nuclear Reassembly after Mitosis
VPS72/YL1-Mediated H2A.Z Deposition Is Required for Nuclear Reassembly after Mitosis
复制标题
DOI：
10.3390/cells9071702
复制
发表时间：
2020-07-01
期刊：
影响因子：
6
通讯作者：
Antonin, Wolfram
中科院分区：
文献类型：
--
作者：
Moreno-Andres, Daniel;Yokoyama, Hideki;Antonin, Wolfram
真核细胞核在有丝分裂过程中广泛重塑。进入有丝分裂期后，核膜破裂，染色体凝聚成杆状体，这些杆状体被纺锤体捕获并在后期分离。在分裂末期，染色体解除致密，核膜重新组装，形成一个有功能的间期核。虽然发生在早期有丝分裂的分子过程进行了深入的研究，我们的知识是相当有限的核重组的分子机制。使用无细胞和细胞分析，我们确定组蛋白变体H2A.Z和其伴侣蛋白VPS 72/YL 1作为有丝分裂后功能性细胞核重新组装的重要因素。活细胞成像显示siRNA介导的VPS 72下调延长了HeLa细胞中的末期。在体外，VPS 72或H2A.Z的消耗导致畸形和无功能的核。VPS 72是两种染色质重塑复合物SRCAP和EP 400的一部分。然而，我们使用无细胞测定来剖析核重组的机制，表明VPS 72在SRCAP和EP 400重塑复合物之外起作用以存款H2 A. Z，这反过来对于功能性核的形成至关重要。
The eukaryotic nucleus remodels extensively during mitosis. Upon mitotic entry, the nuclear envelope breaks down and chromosomes condense into rod-shaped bodies, which are captured by the spindle apparatus and segregated during anaphase. Through telophase, chromosomes decondense and the nuclear envelope reassembles, leading to a functional interphase nucleus. While the molecular processes occurring in early mitosis are intensively investigated, our knowledge about molecular mechanisms of nuclear reassembly is rather limited. Using cell free and cellular assays, we identify the histone variant H2A.Z and its chaperone VPS72/YL1 as important factors for reassembly of a functional nucleus after mitosis. Live-cell imaging shows that siRNA-mediated downregulation of VPS72 extends the telophase in HeLa cells. In vitro, depletion of VPS72 or H2A.Z results in malformed and nonfunctional nuclei. VPS72 is part of two chromatin-remodeling complexes, SRCAP and EP400. Dissecting the mechanism of nuclear reformation using cell-free assays, we, however, show that VPS72 functions outside of the SRCAP and EP400 remodeling complexes to deposit H2A.Z, which in turn is crucial for formation of a functional nucleus.