The schedule of destruction of three mitotic cyclins can dictate the timing of events during exit from mitosis
The schedule of destruction of three mitotic cyclins can dictate the timing of events during exit from mitosis
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DOI：
10.1016/s0960-9822(01)00204-4
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发表时间：
2001-05-01
期刊：
影响因子：
9.2
通讯作者：
O'Farrell, PH
中科院分区：
文献类型：
--
作者：
Parry, DH;O'Farrell, PH
背景：有丝分裂周期蛋白的降解是有丝分裂退出的标志，诱导果蝇的三种有丝分裂周期蛋白，周期蛋白a， B和B3的稳定版本，以不同的表型阻止有丝分裂。我们测试了最近的一个建议，即破坏不同的细胞周期蛋白引导有丝分裂的进程。结果：实时成像显示阻滞表型不同，因为每个稳定周期蛋白对特定有丝分裂事件的影响不同。稳定周期蛋白延长或阻断染色体分离，导致中期停滞。稳定的周期蛋白B允许过渡到后期，但后期A染色体的运动减慢，后期B纺锤体伸长没有发生，单向分离的染色体开始在纺锤极之间振荡。稳定的细胞周期蛋白B3阻止正常的纺锤体成熟，并阻止主要的有丝分裂退出事件，如染色体去浓缩，但仍然允许染色体分离，后期B和形成细胞动力学沟，从而分裂纺锤体。结论：我们得出的结论是，不同的有丝分裂周期蛋白的降解是有丝分裂特定步骤所必需的：周期蛋白A的降解促进了染色体分离，周期蛋白B的破坏是后期B和细胞质分裂以及单价染色体运动方向稳定所必需的，周期蛋白B3的降解是正确的纺锤体重组和间期核恢复所必需的。我们认为细胞周期蛋白A、细胞周期蛋白B和细胞周期蛋白B3的降解时间表有助于有丝分裂事件的时间协调。
Background: Degradation of the mitotic cyclins is a hallmark of the exit from mitosis, Induction of stable versions of each of the three mitotic cyclins of Drosophila, cyclins A, B, and B3, arrests mitosis with different phenotypes. We tested a recent proposal that the destruction of the different cyclins guides progress through mitosis.Results: Real-time imaging revealed that arrest phenotypes differ because each stable cyclin affects specific mitotic events differently. Stable cyclin A prolonged or blocked chromosome disjunction, leading to metaphase arrest. Stable cyclin B allowed the transition to anaphase, but anaphase A chromosome movements were slowed, anaphase B spindle elongation did not occur, and the monooriented disjoined chromosomes began to oscillate between the spindle poles. Stable cyclin B3 prevented normal spindle maturation and blocked major mitotic exit events such as chromosome decondensation but nonetheless allowed chromosome disjunction, anaphase B, and formation of a cytokinetic furrow, which split the spindle.Conclusions: We conclude that degradation of distinct mitotic cyclins is required to transit specific steps of mitosis: cyclin A degradation facilitates chromosome disjunction, cyclin B destruction is required for anaphase B and cytokinesis and for directional stability of univalent chromosome movements, and cyclin B3 degradation is required for proper spindle reorganization and restoration of the interphase nucleus. We suggest that the schedule of degradation of cyclin A, cyclin B, and then cyclin B3 contributes to the temporal coordination of mitotic events.