Dose-dependent effects of stable cyclin B1 on progression through mitosis in human cells
Dose-dependent effects of stable cyclin B1 on progression through mitosis in human cells
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DOI：
10.1038/sj.emboj.7601163
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发表时间：
2006-06-21
期刊：
影响因子：
11.4
通讯作者：
Geley, Stephan
中科院分区：
文献类型：
--
作者：
Wolf, Frank;Wandke, Cornelia;Geley, Stephan
有丝分裂纺锤体的解体和退出有丝分裂需要Cdk 1的失活。在这里，我们表明，非降解细胞周期蛋白B1的表达导致剂量依赖性有丝分裂阻滞表型。通过监测活细胞中的染色体，我们确定了稳定的细胞周期蛋白B1的显著过度表达需要中期停滞而没有可检测到的姐妹染色单体分离，而中度过度表达则使细胞处于假中期状态，其中分离的姐妹染色单体通过双极“中期样”纺锤体保持在细胞赤道。离开假中期板的染色体被拉回，发现单个动粒被merotelically附着在稳定的细胞周期蛋白B1阻滞细胞的两个纺锤体极上。失活的chromokinesin hKid，通过RNAi或抗体显微注射，防止形成稳定的双极纺锤体和'中期样'的染色体在细胞中表达稳定的cyclinB1的对齐。这些实验表明，cyclinB1是能够保持一个双极纺锤体，即使在姐妹染色单体已成为分离，并建议在这个过程中的重要作用的hKid。表达低水平的不可降解的cyclinB1的细胞进一步有丝分裂，并在末期停止。
The disassembly of the mitotic spindle and exit from mitosis require the inactivation of Cdk1. Here, we show that expression of nondegradable cyclinB1 causes dose-dependent mitotic arrest phenotypes. By monitoring chromosomes in living cells, we determined that pronounced overexpression of stable cyclinB1 entailed metaphase arrest without detectable sister chromatid separation, while moderate overexpression arrested cells in a pseudometaphase state, in which separated sister chromatids were kept at the cellular equator by a bipolar 'metaphase-like' spindle. Chromosomes that left the pseudometaphase plate became pulled back and individual kinetochores were found to be merotelically attached to both spindle poles in stable cyclinB1 arrested cells. Inactivation of the chromokinesin hKid, by RNAi or antibody microinjection, prevented the formation of stable bipolar spindles and the 'metaphase-like' alignment of chromosomes in cells expressing stable cyclinB1. These experiments show that cyclinB1 is able to maintain a bipolar spindle even after sister chromatids had become separated and suggest an important role of hKid in this process. Cells expressing low levels of nondegradable cyclinB1 progressed further in mitosis and arrested in telophase.