Structural Memory in the Contractile Ring Makes the Duration of Cytokinesis Independent of Cell Size
Structural Memory in the Contractile Ring Makes the Duration of Cytokinesis Independent of Cell Size
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DOI：
10.1016/j.cell.2009.03.021
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发表时间：
2009-05-29
期刊：
影响因子：
64.5
通讯作者：
Oegema, Karen
中科院分区：
文献类型：
--
作者：
Carvalho, Ana;Desai, Arshad;Oegema, Karen
胞质分裂是通过皮质收缩环的收缩完成的。结果表明，在C.在线虫中，环收缩发生在两个阶段-以恒定速率的初始阶段，随后是第二阶段，在第二阶段期间收缩速率与环周长成比例地降低。胞质分裂在相同的时间内完成，尽管在连续的分裂过程中细胞大小减少，由于初始环大小和恒定的收缩率之间严格成比例。在闭合过程中，环中的肌球蛋白马达与周长成比例地减少，而不翻转。我们提出了一个“收缩单元”模型来解释环如何保持其初始大小的结构记忆，因为它拆卸。收缩的可扩展性可以促进有丝分裂事件和胞质分裂的协调，当细胞大小，因此由环穿过的距离，在胚胎发生期间和在其他情况下变化。
Cytokinesis is accomplished by constriction of a cortical contractile ring. We show that during the early embryonic divisions in C. elegans, ring constriction occurs in two phases-an initial phase at a constant rate followed by a second phase during which the constriction rate decreases in proportion to ring perimeter. Cytokinesis completes in the same amount of time, despite the reduction in cell size during successive divisions, due to a strict proportionality between initial ring size and the constant constriction rate. During closure, the myosin motor in the ring decreases in proportion to perimeter without turning over. We propose a "contractile unit'' model to explain how the ring retains a structural memory of its initial size as it disassembles. The scalability of constriction may facilitate coordination of mitotic events and cytokinesis when cell size, and hence the distance traversed by the ring, varies during embryogenesis and in other contexts.