Mechanics and dynamics of actin-driven thin membrane protrusions
Mechanics and dynamics of actin-driven thin membrane protrusions
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DOI：
10.1529/biophysj.105.071480
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发表时间：
2006-01-01
影响因子：
3.4
通讯作者：
Sun, SX
中科院分区：
文献类型：
--
作者：
Atilgan, E;Wirtz, D;Sun, SX
运动细胞通过延伸薄的动态突起或丝状伪足来探索它们周围的环境。的成长。伪足由位于细胞膜下的肌动蛋白丝束驱动。我们计算的机械和动力学特性的突起生长过程中明确纳入柔性质膜。我们发现，一个临界数量的细丝需要产生净。叶轴生长没有外部的。弗吕恩斯河叶柄可向内延伸。直到F-肌动蛋白束的屈曲长度。动力学计算表明，热膨胀提高了突起速度。膜的波动;包裹在柔性膜中的丝束生长得更快。伸出速度直接取决于束中长丝的数量和空间布置以及纤维束是否被拉伸。悲伤被束缚在膜上。丝状伪足也通过膜的扭曲相互吸引。空间上接近的丝状伪足会合并形成一个更大的丝状伪足。力-速度关系模拟微操作实验测试我们的预测计算。
Motile cells explore their surrounding milieu by extending thin dynamic protrusions, or filopodia. The growth of. lopodia is driven by actin filament bundles that polymerize underneath the cell membrane. We compute the mechanical and dynamical features of the protrusion growth process by explicitly incorporating the flexible plasma membrane. We find that a critical number of filaments are needed to generate net. lopodial growth. Without external in. fluences, the. lopodium can extend inde. nitely up to the buckling length of the F-actin bundle. Dynamical calculations show that the protrusion speed is enhanced by the thermal. uctuations of the membrane; a filament bundle encased in a flexible membrane grows much faster. The protrusion speed depends directly on the number and spatial arrangement of the filaments in the bundle and whether the. laments are tethered to the membrane. Filopodia also attract each other through distortions of the membrane. Spatially close filopodia will merge to form a larger one. Force-velocity relationships mimicking micromanipulation experiments testing our predictions are computed.