Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA)-Institut National de la Recherche Agronomique (INRA), Grenoble, France.
Science. 2012 Jun 8;336(6086):1310-4. doi: 10.1126/science.1221708.
The organization of actin filaments into higher-ordered structures governs eukaryotic cell shape and movement. Global actin network size and architecture are maintained in a dynamic steady state through regulated assembly and disassembly. Here, we used experimentally defined actin structures in vitro to investigate how the activity of myosin motors depends on network architecture. Direct visualization of filaments revealed myosin-induced actin network deformation. During this reorganization, myosins selectively contracted and disassembled antiparallel actin structures, while parallel actin bundles remained unaffected. The local distribution of nucleation sites and the resulting orientation of actin filaments appeared to regulate the scalability of the contraction process. This "orientation selection" mechanism for selective contraction and disassembly suggests how the dynamics of the cellular actin cytoskeleton can be spatially controlled by actomyosin contractility.
肌动蛋白丝形成更高阶结构的组织方式控制着真核细胞的形状和运动。通过调节组装和拆卸，细胞内的全局肌动蛋白网络大小和结构保持在动态平衡状态。在这里，我们使用体外实验定义的肌动蛋白结构来研究肌球蛋白马达的活性如何依赖于网络结构。对肌动蛋白丝的直接可视化揭示了肌球蛋白诱导的肌动蛋白网络变形。在这种重组过程中，肌球蛋白选择性地收缩和解聚了平行的肌动蛋白结构，而平行的肌动蛋白束则不受影响。成核位点的局部分布以及由此产生的肌动蛋白丝的取向似乎调节了收缩过程的可扩展性。这种用于选择性收缩和拆卸的“取向选择”机制表明，细胞肌动蛋白细胞骨架的动力学如何通过肌球蛋白收缩性在空间上得到控制。
