Functional coordination of three mitotic motors in Drosophila embryos
Functional coordination of three mitotic motors in Drosophila embryos
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DOI：
10.1091/mbc.11.1.241
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发表时间：
2000-01-01
影响因子：
3.3
通讯作者：
Scholey, JM
中科院分区：
文献类型：
--
作者：
Sharp, DJ;Brown, HM;Scholey, JM
已经确定，多个基于微管的马达有助于有丝分裂纺锤体的形成和功能，但这些马达的活动如何相互关联仍不清楚。在这里，我们可视化纺锤体的形成在活的果蝇胚胎表明，纺锤体极运动是由三个有丝分裂马达，细胞质动力蛋白，KLP 61 F，和NCD产生的力的时间协调平衡。具体来说，我们的研究结果表明，动力蛋白的行为，以移动两极分开整个有丝分裂，这种活动是由KLP 61 F后，开窗的核膜，一个类似的过程核膜破裂，发生在开始的前中期。相反，我们发现，NCD产生的力量，拉两极之间的间期和中期，拮抗动力蛋白和KLP 61 F的活动，并作为一个刹车主轴组装。然而，在后期，Ncd似乎对纺锤体极运动没有影响，这表明其活性在此时下调，从而使动力蛋白和KLP 61 F在后期B期间驱动纺锤体伸长。
It is well established that multiple microtubule-based motors contribute to the formation and function of the mitotic spindle, but how the activities of these motors interrelate remains unclear. Here we visualize spindle formation in living Drosophila embryos to show that spindle pole movements are directed by a temporally coordinated balance of forces generated by three mitotic motors, cytoplasmic dynein, KLP61F, and Ncd. Specifically, our findings suggest that dynein acts to move the poles apart throughout mitosis and that this activity is augmented by KLP61F after the fenestration of the nuclear envelope, a process analogous to nuclear envelope breakdown, which occurs at the onset of prometaphase. Conversely, we find that Ncd generates forces that pull the poles together between interphase and metaphase, antagonizing the activity of both dynein and KLP61F and serving as a brake for spindle assembly. During anaphase, however, Ncd appears to have no effect on spindle pole movements, suggesting that its activity is downregulated at this time, allowing dynein and KLP61F to drive spindle elongation during anaphase B.