Reconstitution of amoeboid motility in vitro identifies a motor-independent mechanism for cell body retraction.
Reconstitution of amoeboid motility in vitro identifies a motor-independent mechanism for cell body retraction.
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DOI：
10.1016/j.cub.2011.08.047
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发表时间：
2011-10-25
期刊：
影响因子：
9.2
通讯作者：
Roberts, Thomas M.
中科院分区：
文献类型：
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作者：
Shimabukuro, Katsuya;Noda, Naoki;Stewart, Murray;Roberts, Thomas M.
真核细胞的爬行运动需要前缘突出与细胞体缩回的协调。突出是由沿着前缘的肌动蛋白聚合驱动的。回缩机制不太清楚；肌球蛋白收缩性可能与某些细胞有关，但在其他细胞中则不是必需的。在蛔虫精子中，突出和缩回由主要精子蛋白（MSP）运动系统而不是传统的肌动蛋白装置提供动力。这些细胞缺乏运动蛋白，因此非常适合探索不依赖于运动的收缩机制。我们在 MSP 细丝网状结构（称为纤维）中同时重建了突出和收缩，这些网状结构在质膜衍生的囊泡后面组装。收缩是由纤维后部完整长丝的解聚引发的。幸存的细丝重新组织以维持其堆积密度。通过将更少的长丝填充到更小的体积中，解聚网络会收缩，从而产生足够的力来移动附着的负载。因此，这项工作为线虫精子重建的 MSP 运动系统中与运动无关的回缩提供了直接证据。这种机制也适用于基于肌动蛋白的细胞，并且可以解释细胞即使在肌球蛋白活性受到损害时也会爬行的报道。
Crawling movement in eukaryotic cells requires coordination of leading edge protrusion with cell body retraction. Protrusion is driven by actin polymerization along the leading edge. The mechanism of retraction is less clear; myosin contractility may be involved in some cells but is not essential in others. In Ascaris sperm, protrusion and retraction are powered by the major sperm protein (MSP) motility system instead of the conventional actin apparatus. These cells lack motor proteins and so are well-suited to explore motor-independent mechanisms of retraction. We reconstituted protrusion and retraction simultaneously in MSP filament meshworks, called fibers, that assemble behind plasma membrane-derived vesicles. Retraction is triggered by depolymerization of complete filaments in the rear of the fiber. The surviving filaments reorganize to maintain their packing density. By packing fewer filaments into a smaller volume the depolymerizing network shrinks and thereby generates sufficient force to move an attached load. Thus, this work provides direct evidence for motor-independent retraction in the reconstituted MSP motility system of nematode sperm. This mechanism could also apply to actin-based cells and may explain reports of cells that crawl even when their myosin activity is compromised.
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影响因子：
3.3
作者：
Katoh, K;Hammar, K;Oldenbourg, R
通讯作者：
Oldenbourg, R
影响因子：
9.2
作者：
Cameron, LA;Svitkina, TM;Borisy, GG
通讯作者：
Borisy, GG
影响因子：
64.8
作者：
Oldenbourg, R
通讯作者：
Oldenbourg, R
影响因子：
56.9
作者：
KNECHT, DA;LOOMIS, WF
通讯作者：
LOOMIS, WF
DOI：
10.1038/nrm2786
发表时间：
2009-11
期刊：
Nature reviews. Molecular cell biology
影响因子：
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作者：
通讯作者：
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