Defects in centromeric/pericentromeric histone H2A T120 phosphorylation by hBUB1 cause chromosome missegregation producing multinucleated cells
Defects in centromeric/pericentromeric histone H2A T120 phosphorylation by hBUB1 cause chromosome missegregation producing multinucleated cells
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hBUB1 引起的着丝粒/着丝粒周围组蛋白 H2A T120 磷酸化缺陷导致染色体错误分离，产生多核细胞
DOI：
10.1111/gtc.12630
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发表时间：
2018
期刊：
影响因子：
2.1
通讯作者：
Ito Takashi
中科院分区：
文献类型：
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作者：
Maeda Katsutoshi;Yoneda Mitsuhiro;Nakagawa Takeya;Ikeda Kazuhiro;Higashi Miki;Nakagawa Kaori;Miyakoda Mana;Yui Katsuyuki;Oda Hiroaki;Inoue Satoshi;Ito Takashi
组蛋白H_2A的磷酸化在有丝分裂过程中的染色质凝聚和在G1/S转变过程中的转录激活中都起着重要作用。BUB1和NHK1/VRK1已被鉴定为组蛋白H_2A激酶。然而，人们对组蛋白H_2A磷酸化在染色体分离中的重要性知之甚少。在此，我们表达了重组的hBUB1，并证实它能磷酸化体外组装的核小体中的组蛋白H_2A_T120。在HeLa细胞中，BUB1的敲除(KD)降低了H_2A_(T120)的整体磷酸化，而hBUB1在有丝分裂过程中上调，这与H_2A_(T120)的磷酸化相对应。DXZ1着丝粒和γ-ALR着丝粒周围区域的芯片定量聚合酶链式反应显示，Bub1定位于该区域，并在M期增加局部的H2A T120的磷酸化；BUB1KD不诱导细胞凋亡，但增加了M期细胞的数量；BUB1KD还引起中期和末期的异常，导致多核细胞和癌细胞在体内外的生长受阻。模拟磷酸化苏氨酸的组蛋白H2 A T120D或T120E突变的过表达减少了BUB1KD引起的多核细胞的数量。这些结果加强了Bub1介导的H2 A T120磷酸化在正常有丝分裂中的明显重要性。
Histone H2A phosphorylation plays a role both in chromatin condensation during mitosis and in transcriptional activation during the G1/S transition. Bub1 and NHK1/VRK1 have been identified as histone H2A kinases. However, little is known about the importance of histone H2A phosphorylation in chromosome segregation. Here, we expressed recombinant hBUB1 and confirmed that it phosphorylates histone H2A T120 in the in vitro‐assembled nucleosome. Knockdown (KD) ofBUB1decreases bulk H2A T120 phosphorylation in HeLa cells, whereas hBUB1 is upregulated during mitosis, which corresponds with H2A T120 phosphorylation. ChIP‐qPCR of the DXZ1 centromeric and γ‐ALR pericentromeric region showed that BUB1 localizes to this region and increases local H2A T120 phosphorylation during M phase.BUB1KD did not induce apoptosis but increased the M phase cell population, as detected by flow cytometry.BUB1KD also caused an abnormal metaphase and telophase, resulting in multinucleated cells and impaired cancer cell growth both in vitro and in vivo. Over‐expression of the histone H2A T120D or T120E mutations, which mimic phosphorylated threonine, decreased the number of multinucleated cells caused byBUB1KD. These results strengthen the apparent importance of BUB1‐mediated H2A T120 phosphorylation in normal mitosis.