Aurora kinase inhibitor ZM447439 blocks chromosome-induced spindle assembly, the completion of chromosome condensation, and the establishment of the spindle integrity checkpoint in Xenopus egg extracts
Aurora kinase inhibitor ZM447439 blocks chromosome-induced spindle assembly, the completion of chromosome condensation, and the establishment of the spindle integrity checkpoint in Xenopus egg extracts
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DOI：
10.1091/mbc.e04-10-0891
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发表时间：
2005-03-01
影响因子：
3.3
通讯作者：
Ruderman, JV
中科院分区：
文献类型：
--
作者：
Gadea, BB;Ruderman, JV
极光家族的激酶有助于通过几个有丝分裂事件的准确进展。ZM447439(“ZM”)是第一个被开发和鉴定的Aurora家族激酶抑制剂，以前被发现干扰有丝分裂纺锤体完整性检查点和染色体分离。在这里，我们使用非洲爪哇卵的提取物，通常在没有功能检查点的情况下进行早期胚胎细胞周期，以区分ZM对基本细胞周期机制的影响和它对检查点的影响。ZM显然对几个关键的细胞周期调节因子的活动振荡的动力学或幅度都没有影响。然而，它确实对染色体形态产生了显著的影响。在ZM存在的情况下，染色体凝聚按计划开始，但随后无法正常进行；相反，染色体在有丝分裂中期过早解聚。ZM通过抑制由染色质成核/稳定的微管的形成，强烈干扰有丝分裂纺锤体的组装。相比之下，ZM对纺锤体极点的中心体组装微管几乎没有影响。最后，在实验诱导了心轴完整性检查点的条件下，ZM阻止了检查点蛋白MAD2上游的检查点的建立，但不阻止检查点的维持。这些结果表明，极光激酶活性是确保染色体浓缩的维持、染色体诱导的纺锤体微管的产生以及纺锤体完整性检查点的激活所必需的。
The Aurora family kinases contribute to accurate progression through several mitotic events. ZM447439 ("ZM"), the first Aurora family kinase inhibitor to be developed and characterized, was previously found to interfere with the mitotic spindle integrity checkpoint and chromosome segregation. Here, we have used extracts of Xenopus eggs, which normally proceed through the early embryonic cell cycles in the absence of functional checkpoints, to distinguish between ZM's effects on the basic cell cycle machinery and its effects on checkpoints. ZM clearly had no effect on either the kinetics or amplitude in the oscillations of activity of several key cell cycle regulators. It did, however, have striking effects on chromosome morphology. In the presence of ZM, chromosome condensation began on schedule but then failed to progress properly; instead, the chromosomes underwent premature decondensation during mid-mitosis. ZM strongly interfered with mitotic spindle assembly by inhibiting the formation of microtubules that are nucleated/stabilized by chromatin. By contrast, ZM had little effect on the assembly of microtubules by centrosomes at the spindle poles. Finally, under conditions where the spindle integrity checkpoint was experimentally induced, ZM blocked the establishment, but not the maintenance, of the checkpoint, at a point upstream of the checkpoint protein Mad2. These results show that Aurora kinase activity is required to ensure the maintenance of condensed chromosomes, the generation of chromosome-induced spindle microtubules, and activation of the spindle integrity checkpoint.