Mechanism of actin network attachment to moving membranes: Barbed end capture by N-WASP WH2 domains
Mechanism of actin network attachment to moving membranes: Barbed end capture by N-WASP WH2 domains
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DOI：
10.1016/j.cell.2006.12.049
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发表时间：
2007-03-09
期刊：
影响因子：
64.5
通讯作者：
Taunton, Jack
中科院分区：
文献类型：
--
作者：
Co, Carl;Wong, Derek T.;Taunton, Jack
肌动蛋白丝网络在膜上施加膨胀力和附着力，从而驱动膜变形和运动。在这里，我们表明，N-WASP WH 2域发挥了前所未有的作用，在囊泡运动的瞬时连接肌动蛋白丝倒钩结束的膜。为了剖析附着机制，我们使用纯化的可溶性蛋白质重建了脂质包被的玻璃珠的推进运动。N-WASP WH 2突变体组装肌动蛋白彗星尾巴并启动运动，但彗星尾巴灾难性地从膜上脱落。当呈现在脂质包被的珠粒的表面上时，WH 2结构域足以维持彗星尾附着。在v-Src转化的成纤维细胞中，N-WASP WH 2突变体在形成圆形podosome阵列方面存在严重缺陷。除了产生附着力，WH 2结构域和倒刺末端之间的相互作用可以局部放大树突状肌动蛋白成核的信号。
Actin filament networks exert protrusive and attachment forces on membranes and thereby drive membrane deformation and movement. Here, we show that N-WASP WH2 domains play a previously unanticipated role in vesicle movement by transiently attaching actin filament barbed ends to the membrane. To dissect the attachment mechanism, we reconstituted the propulsive motility of lipid-coated glass beads, using purified soluble proteins. N-WASP WH2 mutants assembled actin comet tails and initiated movement, but the comet tails catastrophically detached from the membrane. When presented on the surface of a lipid-coated bead, WH2 domains were sufficient to maintain comet tail attachment. In v-Src-transformed fibroblasts, N-WASP WH2 mutants were severely defective in the formation of circular podosome arrays. In addition to creating an attachment force, interactions between WH2 domains and barbed ends may locally amplify signals for dendritic actin nucleation.