The highly conserved Ndc80 complex is required for kinetochore assembly, chromosome congression, and spindle checkpoint activity
The highly conserved Ndc80 complex is required for kinetochore assembly, chromosome congression, and spindle checkpoint activity
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DOI：
10.1101/gad.1040903
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发表时间：
2003-01-01
影响因子：
10.5
通讯作者：
Stukenberg, PT
中科院分区：
文献类型：
--
作者：
McCleland, ML;Gardner, RD;Stukenberg, PT
我们发现，爪蟾同系物Ndc 80/Tid 3/HEC 1（xNdc 80）和Nuf 2/MPP 1/Him-10（xNuf 2）蛋白质物理上相互作用，在一个190 kD的复合物，该复合物与外部动粒从早中期到后期。将xNdc 80或xNuf 2的功能阻断抗体注射到XTC细胞中，导致有丝分裂提前退出，而没有可检测到的染色体聚集或后期运动。注射的细胞没有响应微管药物而停止，表明该复合物是纺锤体检查点所需的。在免疫耗竭复合物后，在爪蟾提取物中组装的动粒不含xRod、xZw 10、xP 150胶合（Dynactin）、xMad 1、xMad 2、xBub 1和xBub 3，表明xNdc 80复合物是功能性动粒组装所需的。与此相反，功能阻断抗体不影响其他动粒蛋白的定位时，添加到含有先前组装的动粒提取物。这些提取物与完整的动粒是缺乏检查点信号，这表明Ndc 80复合物参与纺锤体检查点。我们还表明，纺锤体检查点可以逮捕芽殖酵母细胞缺乏Ndc 80或Nuf 2，而酵母缺乏这两种蛋白质不能逮捕有丝分裂。酵母动粒基因的系统性缺失表明Ndc 80复合物在纺锤体检查点信号传导中具有独特的作用。我们认为Ndc 80复合物在动粒组装、染色体组装和纺锤体检查点信号传导中具有保守的作用。
We show that the Xenopus homologs of Ndc8o/Tid3/HEC1 (xNdc80) and Nuf2/MPP1/Him-10 (xNuf2) proteins physically interact in a 190-kD complex that associates with the outer kinetochore from prometaphase through anaphase. Injecting function-blocking antibodies to either xNdc80 or xNuf2 into XTC cells caused premature exit from mitosis without detectable chromosome congression or anaphase movements. Injected cells did not arrest in response to microtubule drugs, showing that the complex is required for the spindle checkpoint. Kinetochores assembled in Xenopus extracts after immunodepletion of the complex did not contain xRod, xZw10, xP150 glued (Dynactin), xMad1, xMad2, xBub1, and xBub3, demonstrating that the xNdc80 complex is required for functional kinetochore assembly. In contrast, function-blocking antibodies did not affect the localization of other kinetochore proteins when added to extracts containing previously assembled kinetochores. These extracts with intact kinetochores were deficient in checkpoint signaling, suggesting that the Ndc80 complex participates in the spindle checkpoint. We also demonstrate that the spindle checkpoint can arrest budding yeast cells lacking Ndc80 or Nuf2, whereas yeast lacking both proteins fail to arrest in mitosis. Systematic deletion of yeast kinetochore genes suggests that the Ndc80 complex has a unique role in spindle checkpoint signaling. We propose that the Ndc80 complex has conserved roles in kinetochore assembly, chromosome congression, and spindle checkpoint signaling.