Reconstitution of actin-based motility of Listeria and Shigella using pure proteins
Reconstitution of actin-based motility of Listeria and Shigella using pure proteins
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DOI：
10.1038/44183
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发表时间：
1999-10-07
期刊：
影响因子：
64.8
通讯作者：
Carlier, MF
中科院分区：
文献类型：
--
作者：
Loisel, TP;Boujemaa, R;Carlier, MF
肌动蛋白聚合对于细胞运动是必不可少的，并且被认为产生负责细胞突起的力。Arp 2/3复合物是刺激肌动蛋白在前沿组装以响应信号传导所必需的（1-6）。细菌李斯特菌和志贺氏菌绕过信号通路并利用Arp 2/3复合物来诱导肌动蛋白组装并在活细胞中推动自己（7-10）。然而，Arp 2/3复合物本身不足以促进运动。在这里，我们已经使用纯组分的肌动蛋白细胞骨架，以重建持续运动的李斯特菌和志贺氏菌在体外。基于肌动蛋白的推进由与肌动蛋白聚合相关的ATP水解释放的自由能驱动，并且不需要肌球蛋白。除了肌动蛋白和活化的Arp 2/3复合物之外，肌动蛋白解聚因子（ADF或cofilin）和加帽蛋白也是运动所需的，因为它们维持高稳态水平的G-肌动蛋白，其控制肌动蛋白丝在细菌表面的单向生长速率。当profilin，alpha-actinin和VASP（李斯特菌）也包括在内时，运动更有效。这些结果对我们理解肌动蛋白为基础的细胞运动的机制具有重要意义。
Actin polymerization is essential for cell locomotion and is thought to generate the force responsible for cellular protrusions. The Arp2/3 complex is required to stimulate actin assembly at the leading edge in response to signalling(1-6). The bacteria Listeria and Shigella bypass the signalling pathway and harness the Arp2/3 complex to induce actin assembly and to propel themselves in living cells(7-10). However, the Arp2/3 complex alone is insufficient to promote movement. Here we have used pure components of the actin cytoskeleton to reconstitute sustained movement in Listeria and Shigella in vitro. Actin-based propulsion is driven by the free energy released by ATP hydrolysis linked to actin polymerization, and does not require myosin. In addition to actin and activated Arp2/3 complex, actin depolymerizing factor (ADF, or cofilin) and capping protein are also required for motility as they maintain a high steady-state level of G-actin, which controls the rate of unidirectional growth of actin filaments at the surface of the bacterium. The movement is more effective when profilin, alpha-actinin and VASP (for Listeria) are also included. These results have implications for our understanding of the mechanism of actin-based motility in cells.