Myosin II-dependent cortical movement is required for centrosome separation and positioning during mitotic spindle assembly
Myosin II-dependent cortical movement is required for centrosome separation and positioning during mitotic spindle assembly
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DOI：
10.1016/s0092-8674(04)00341-1
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发表时间：
2004-04-30
期刊：
影响因子：
64.5
通讯作者：
McGee, KM
中科院分区：
文献类型：
--
作者：
Rosenblatt, J;Cramer, LP;McGee, KM
一般认为肌球蛋白II在有丝分裂中的作用仅限于胞质分裂。我们提出了令人惊讶的新证据，皮质肌球蛋白II也需要在细胞中的纺锤体组装。药物或RNAi介导的细胞中肌球蛋白II的破坏干扰正常的纺锤体组装和定位。延时电影显示，这些治疗方法阻止了核被膜破裂（NEBD）后重复中心体的分离和定位，从而阻止了微管星状体向染色体两侧的迁移。固定化的皮质运动与四价凝集素产生类似的纺锤体缺陷肌球蛋白II中断，并建议肌球蛋白II的活性是必需的皮质内。结合到细胞表面的乳胶珠以肌球蛋白II依赖的方式向分离星状体的方向移动。我们建议，NEBD后，完成中心体分离和定位周围的染色体依赖于星形微管连接到一个移动的细胞皮质。
The role of myosin II in mitosis is generally thought to be restricted to cytokinesis. We present surprising new evidence that cortical myosin II is also required for spindle assembly in cells. Drug- or RNAi-mediated disruption of myosin II in cells interferes with normal spindle assembly and positioning. Time-lapse movies reveal that these treatments block the separation and positioning of duplicated centrosomes after nuclear envelope breakdown (NEBD), thereby preventing the migration of the microtubule asters to opposite sides of chromosomes. Immobilization of cortical movement with tetravalent lectins produces similar spindle defects to myosin II disruption and suggests that myosin II activity is required within the cortex. Latex beads bound to the cell surface move in a myosin II-dependent manner in the direction of the separating asters. We propose that after NEBD, completion of centrosome separation and positioning around chromosomes depends on astral microtubule connections to a moving cell cortex.