Dissecting the roles of Haspin and VRK1 in Histone H3 threonine-3 phosphorylation during mitosis
Dissecting the roles of Haspin and VRK1 in Histone H3 threonine-3 phosphorylation during mitosis
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DOI：
10.1101/2021.09.07.459242
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
T. Cartwright;Rebecca J. Harris;Stephanie K. Meyer;Nikolaus A. Watson;C. Tan;Fangwei Wang;J. Higgins-J.-Higgi
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文献类型：
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作者：
T. Cartwright;Rebecca J. Harris;Stephanie K. Meyer;Nikolaus A. Watson;C. Tan;Fangwei Wang;J. Higgins-J.-Higgi
使组蛋白磷酸化的蛋白激酶被理想地放置以影响细胞分裂期间染色体的行为。事实上，许多保守的组蛋白磷酸化事件在大多数真核生物的有丝分裂和减数分裂期间显著发生，包括在组蛋白H3上的苏氨酸-3（H3 T3 ph）。已经提出至少两种激酶Haspin和VRK 1（果蝇中的NHK-1/ballchen）进行这种修饰。Haspin对H3的磷酸化在有丝分裂中具有明确的作用，但VRK 1活性对分裂细胞中组蛋白的意义尚不清楚。在这里，使用体外激酶测定、KiPIK筛选、RNA干扰和CRISPR/Cas9方法，我们无法证实VRK 1或其同源物VRK 2在有丝分裂中组蛋白H3的苏氨酸-3或丝氨酸-10磷酸化中的直接作用，尽管VRK 1的丢失确实减缓了细胞增殖。我们的结论是，VRK 1的作用，其最近确定的关联与人类神经肌肉疾病，是不太可能涉及有丝分裂组蛋白激酶活性。相反，Haspin需要在有丝分裂期间产生H3 T3 ph。
Protein kinases that phosphorylate histones are ideally-placed to influence the behavior of chromosomes during cell division. Indeed, a number of conserved histone phosphorylation events occur prominently during mitosis and meiosis in most eukaryotes, including on histone H3 at threonine-3 (H3T3ph). At least two kinases, Haspin and VRK1 (NHK-1/ballchen in Drosophila), have been proposed to carry out this modification. Phosphorylation of H3 by Haspin has defined roles in mitosis, but the significance of VRK1 activity towards histones in dividing cells has been unclear. Here, using in vitro kinase assays, KiPIK screening, RNA interference, and CRISPR/Cas9 approaches, we were unable to substantiate a direct role for VRK1, or its homologue VRK2, in the phosphorylation of threonine-3 or serine-10 of Histone H3 in mitosis, although loss of VRK1 did slow cell proliferation. We conclude that the role of VRK1, and its more recently identified association with neuromuscular disease in humans, is unlikely to involve mitotic histone kinase activity. In contrast, Haspin is required to generate H3T3ph during mitosis.