Cell-sized spherical confinement induces the spontaneous formation of contractile actomyosin rings in vitro
Cell-sized spherical confinement induces the spontaneous formation of contractile actomyosin rings in vitro
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DOI：
10.1038/ncb3142
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发表时间：
2015-04-01
影响因子：
21.3
通讯作者：
Ishiwata, Shin'ichi
中科院分区：
文献类型：
--
作者：
Miyazaki, Makito;Chiba, Masataka;Ishiwata, Shin'ichi
在细胞分裂过程中，许多动物细胞转变成球形，并在赤道组装一个由肌动蛋白丝和肌球蛋白马达组成的收缩环，将细胞体一分为二。虽然肌动球蛋白调节蛋白质的时空控制胞质分裂，细胞形状和肌动球蛋白活性的收缩环组装的直接贡献仍然不清楚。在这里，我们证明了在体外细胞大小的球形液滴内的肌动蛋白聚合诱导自发形成的单个环形肌动蛋白束的存在下，捆绑因子。尽管缺乏空间调节信号，环总是在赤道组装，以最大限度地减少束的弹性能。肌球蛋白促进环形成的动态重塑肌动蛋白网络，并在肌球蛋白的有效浓度的增加触发环收缩。这些结果将有助于我们了解动物细胞如何协调细胞形状和肌动球蛋白活性来指导胞质分裂。
During cell division, many animal cells transform into a spherical shape and assemble a contractile ring composed of actin filaments and myosin motors at the equator to separate the cell body into two. Although actomyosin regulatory proteins are spatio-temporally controlled during cytokinesis, the direct contribution of cell shape and actomyosin activity to the contractile ring assembly remains unclear. Here, we demonstrated in vitro that actin polymerization inside cell-sized spherical droplets induced the spontaneous formation of single ring-shaped actin bundles in the presence of bundling factors. Despite a lack of spatial regulatory signals, the rings always assembled at the equator to minimize the elastic energy of the bundles. Myosin promoted ring formation by the dynamic remodelling of actin networks, and an increase in the effective concentration of myosin triggered ring contraction. These results will help us understand how animal cells coordinate cell shape and actomyosin activities to direct cytokinesis.