Limits of filopodium stability
Limits of filopodium stability
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DOI：
10.1103/physrevlett.100.258102
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发表时间：
2008-06-27
影响因子：
8.6
通讯作者：
Fletcher, Daniel A.
中科院分区：
文献类型：
--
作者：
Pronk, Sander;Geissler, Phillip L.;Fletcher, Daniel A.
丝状伪足是由细胞骨架丝支撑的长的指状膜管。它们的形状是由它们内部的肌动蛋白丝束的刚度以及膜的表面张力和弯曲刚度之间的相互作用决定的。虽然人们可能会期望欧拉屈曲不稳定性，以限制丝状伪足的长度，我们表明，通过简单的精力充沛的考虑，这是在一般情况下，不是这样的。通过进一步分析膜管内细丝的静力学，并通过计算机模拟捕获膜和细丝的波动，我们显示在何种条件下，任意长度的丝状伪足是稳定的。我们讨论了几个已经观察到这种稳定性的体外实验。此外，我们预测，在长，稳定的丝状伪足的细丝采取螺旋形状。
Filopodia are long, fingerlike membrane tubes supported by cytoskeletal filaments. Their shape is determined by the stiffness of the actin filament bundles found inside them and by the interplay between the surface tension and bending rigidity of the membrane. Although one might expect the Euler buckling instability to limit the length of filopodia, we show through simple energetic considerations that this is in general not the case. By further analyzing the statics of filaments inside membrane tubes, and through computer simulations that capture membrane and filament fluctuations, we show under which conditions filopodia of arbitrary lengths are stable. We discuss several in vitro experiments where this kind of stability has already been observed. Furthermore, we predict that the filaments in long, stable filopodia adopt a helical shape.