Active gels: dynamics of patterning and self-organization
Active gels: dynamics of patterning and self-organization
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DOI：
10.1088/1478-3975/3/4/004
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发表时间：
2006-12-01
期刊：
影响因子：
2
通讯作者：
Bernheim-Groswasser, A.
中科院分区：
文献类型：
--
作者：
Backouche, F.;Haviv, L.;Bernheim-Groswasser, A.
肌动蛋白细胞骨架是一种活性凝胶，在细胞运动和分裂过程中不断重塑。肌球蛋白II分子马达参与这种主动重塑过程，因此控制细胞骨架结构的动态自组织。由于体内系统的复杂性，很难研究肌球蛋白II在决定细胞骨架结构的重组过程中的作用。在这里，我们使用一个体外模型系统，表明肌球蛋白II积极重组肌动蛋白成各种介观模式，但只有在捆绑蛋白的存在下。我们发现，重组过程的性质是复杂的，表现出的模式和动力学现象，而不是预测当前的理论模型，并没有观察到相应的被动系统（不包括电机）。该系统根据马达和捆绑蛋白质的浓度产生活跃的网络、星形甚至环。此外，马达产生图案的形成，但在临界浓度以上，它们也可以分解它们，甚至完全阻止肌动蛋白丝的聚合和成束。这些结果可能表明，调整的组装和拆卸的细胞骨架结构，可以通过调整局部肌球蛋白II浓度/活性。
The actin cytoskeleton is an active gel which constantly remodels during cellular processes such as motility and division. Myosin II molecular motors are involved in this active remodeling process and therefore control the dynamic self-organization of cytoskeletal structures. Due to the complexity of in vivo systems, it is hard to investigate the role of myosin II in the reorganization process which determines the resulting cytoskeletal structures. Here we use an in vitro model system to show that myosin II actively reorganizes actin into a variety of mesoscopic patterns, but only in the presence of bundling proteins. We find that the nature of the reorganization process is complex, exhibiting patterns and dynamical phenomena not predicted by current theoretical models and not observed in corresponding passive systems (excluding motors). This system generates active networks, asters and even rings depending on motor and bundling protein concentrations. Furthermore, the motors generate the formation of the patterns, but above a critical concentration they can also disassemble them and even totally prevent the polymerization and bundling of actin filaments. These results may suggest that tuning the assembly and disassembly of cytoskeletal structures can be obtained by tuning the local myosin II concentration/activity.