The role of filament-packing dynamics in powering amoeboid cell motility
The role of filament-packing dynamics in powering amoeboid cell motility
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DOI：
10.1073/pnas.0708416105
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发表时间：
2008-04-08
影响因子：
11.1
通讯作者：
Roberts, Thomas M.
中科院分区：
文献类型：
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作者：
Miao, Long;Vanderlinde, Orion;Roberts, Thomas M.
虽然已经提出了几种模型来解释细胞骨架聚合如何驱动细胞运动的突起，但确切的机制仍然存在争议。在这里，我们表明，除了直接施加在膜上的力，通过生长细丝，拉长细丝包的方式也有助于通过产生细胞骨架凝胶的膨胀而突出。断层扫描显示，长丝包装在主要的精子蛋白（MSP）为基础的线虫精子运动机制类似于观察到的刚性杆。最大棒填充密度随着棒的延长而显著降低。因此，当细丝伸长时，细胞骨架凝胶膨胀以适应它们较不密集的堆积。这种体积膨胀与聚合作用相结合以驱动突起。与这一假设相一致，产生较短细丝的工程改造MSP突变体显示出较高的顺应性堆积密度和较慢的运动。
Although several models have been proposed to account for how cytoskeleton polymerization drives protrusion in cell motility, the precise mechanism remains controversial. Here, we show that, in addition to force exerted directly against the membrane by growing filaments, the way elongating filaments pack also contributes to protrusion by generating an expansion of the cytoskeleton gel. Tomography shows that filament packing in the major sperm protein (MSP)-based nematode sperm-motility machinery resembles that observed with rigid rods. Maximum rod-packing density decreases dramatically as the rods lengthen. Therefore, as filaments elongate, the cytoskeleton gel expands to accommodate their packing less densely. This volume expansion combines with polymerization to drive protrusion. Consistent with this hypothesis, an engineered MSP mutant that generates shorter filaments shows higher filament-packing density and slower movement.