Cyclin B degradation leads to NuMA release from dynein/dynactin and from spindle poles
Cyclin B degradation leads to NuMA release from dynein/dynactin and from spindle poles
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DOI：
10.1038/sj.embor.7400046
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发表时间：
2004-01-01
期刊：
影响因子：
7.7
通讯作者：
Merdes, A
中科院分区：
文献类型：
--
作者：
Gehmlich, K;Haren, L;Merdes, A
蛋白质NuMA定位于有丝分裂纺锤体极，在那里它有助于微管的组织。在这项研究中，我们证明，NuMA失去了稳定的协会与纺锤体极后期发病后。使用爪蟾卵提取物，我们表明，NuMA是在后期去磷酸化，并释放动力蛋白和动力肌动蛋白。在存在不可降解形式的细胞周期蛋白B（Delta90）的情况下，NuMA保持磷酸化并与动力蛋白和动力蛋白结合，并保持定位于稳定的纺锤体极，这些纺锤体极在有丝分裂结束时不能分解。抑制NuMA或动力蛋白允许完成有丝分裂，尽管诱导纺锤体极异常。我们建议，NuMA功能在有丝分裂早期纺锤体极的形成过程中，但后期后从纺锤体释放，使纺锤体拆卸和微管网络的重塑。
The protein NuMA localizes to mitotic spindle poles where it contributes to the organization of microtubules. In this study, we demonstrate that NuMA loses its stable association with the spindle poles after anaphase onset. Using extracts from Xenopus laevis eggs, we show that NuMA is dephosphorylated in anaphase and released from dynein and dynactin. In the presence of a nondegradable form of cyclin B (Delta90), NuMA remains phosphorylated and associated with dynein and dynactin, and remains localized to stable spindle poles that fail to disassemble at the end of mitosis. inhibition of NuMA or dynein allows completion of mitosis, despite inducing spindle pole abnormalities. We propose that NuMA functions early in mitosis during the formation of spindle poles, but is released from the spindle after anaphase, to allow spindle disassembly and remodelling of the microtubule network.