Aurora B controls the association of condensin I but not condensin II with mitotic chromosomes
Aurora B controls the association of condensin I but not condensin II with mitotic chromosomes
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DOI：
10.1242/jcs.03425
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发表时间：
2007-04-01
影响因子：
4
通讯作者：
Peters, Jan-Michael
中科院分区：
文献类型：
--
作者：
Lipp, Jesse J.;Hirota, Toru;Peters, Jan-Michael
有丝分裂染色体的装配是由凝聚素复合体控制的。在脊椎动物中，凝聚素I在前中期与染色质结合，赋予染色体刚性并使粘着素复合物从染色体臂释放，而凝聚素II在前期与染色体结合并促进其凝聚。这两种复合体都是后期染色体分离所必需的。尽管凝聚素与染色质的结合对于有丝分裂染色体的组装和分离是重要的，但人们对这一过程是如何控制的知之甚少。在这里，我们表明，有丝分裂激酶极光B调节凝聚素I的协会，但不是凝聚素II与染色质的相互作用。表达GFP标记的凝聚素亚基的细胞的定量延时成像显示，Aurora B是在前中期将凝聚素I有效装载到染色体上和在有丝分裂后期维持染色体上的复合物所必需的。凝聚素I的三个非SMC亚基在体外是Aurora B底物，在体内它们的有丝分裂特异性磷酸化依赖于Aurora B。我们的数据表明，极光B有助于染色体的刚性和分离，通过促进凝聚蛋白I的染色质的结合。我们还讨论了极光B如何可能介导的染色体臂的粘连蛋白的解离。
The assembly of mitotic chromosomes is controlled by condensin complexes. In vertebrates, condensin I binds to chromatin in prometaphase, confers rigidity to chromosomes and enables the release of cohesin complexes from chromosome arms, whereas condensin II associates with chromosomes in prophase and promotes their condensation. Both complexes are essential for chromosome segregation in anaphase. Although the association of condensins with chromatin is important for the assembly and segregation of mitotic chromosomes, it is poorly understood how this process is controlled. Here we show that the mitotic kinase Aurora B regulates the association of condensin I, but not the interaction of condensin II with chromatin. Quantitative time-lapse imaging of cells expressing GFP-tagged condensin subunits revealed that Aurora B is required for efficient loading of condensin I onto chromosomes in prometaphase and for maintenance of the complex on chromosomes in later stages of mitosis. The three non-SMC subunits of condensin I are Aurora B substrates in vitro and their mitosis-specific phosphorylation depends on Aurora B in vivo. Our data indicate that Aurora B contributes to chromosome rigidity and segregation by promoting the binding of condensin I to chromatin. We have also addressed how Aurora B might mediate the dissociation of cohesin from chromosome arms.