Force-induced adsorption and anisotropic growth of focal adhesions
Force-induced adsorption and anisotropic growth of focal adhesions
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DOI：
10.1529/biophysj.105.074377
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发表时间：
2006-05-01
影响因子：
3.4
通讯作者：
Safran, SA
中科院分区：
文献类型：
--
作者：
Besser, A;Safran, SA
局灶性粘连是将肌动蛋白应力纤维连接到细胞外基质的微米大小的蛋白质聚集体，细胞外基质是组织细胞周围的大分子网络。由于肌动蛋白-肌球蛋白的收缩性，肌动蛋白纤维处于张力下。最近的测量表明，随着肌动蛋白力的增加，这些粘连的大小和力的方向都会增加。这是相反的凝聚域的表面吸附的分子，其中的动力学是各向同性的增长。我们预测这些力敏感的，各向异性的动力学局灶性粘连的蛋白质从细胞质的吸附到粘附位点的模型。我们的理论耦合的机械力和弹性的吸附动力学通过力诱导的构象变化的分子大小的mechanosensors位于粘着斑。我们预测的速度的前面和后面的粘附力的函数。此外，我们的研究结果表明，粘附力的前后相对运动是不对称的，在不同的力的范围内，粘附力可以沿着力的方向收缩或增长。
Focal adhesions are micrometer-sized protein aggregates that connect actin stress fibers to the extracellular matrix, a network of macromolecules surrounding tissue cells. The actin fibers are under tension due to actin-myosin contractility. Recent measurements have shown that as the actin force is increased, these adhesions grow in size and in the direction of the force. This is in contrast to the growth of condensed domains of surface-adsorbed molecules in which the dynamics are isotropic. We predict these force-sensitive, anisotropic dynamics of focal adhesions from a model for the adsorption of proteins from the cytoplasm to the adhesion site. Our theory couples the mechanical forces and elasticity to the adsorption dynamics via force-induced conformational changes of molecular-sized mechanosensors located in the focal adhesion. We predict the velocity of both the front and back of the adhesion as a function of the applied force. In addition, our results show that the relative motion of the front and back of the adhesion is asymmetric and in different ranges of forces, the adhesion can either shrink or grow in the direction of the force.