Pivotal role of VASP in Arp2/3 complex-mediated actin nucleation, actin branch-formation, and Listeria monocytogenes motility
Pivotal role of VASP in Arp2/3 complex-mediated actin nucleation, actin branch-formation, and Listeria monocytogenes motility
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DOI：
10.1083/jcb.200106061
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发表时间：
2001-10-01
影响因子：
7.8
通讯作者：
Portnoy, DA
中科院分区：
文献类型：
--
作者：
Skoble, J;Auerbuch, V;Portnoy, DA
单核细胞增生李斯特菌ActA蛋白通过募集和刺激Arp 2/3复合物来介导基于肌动蛋白的运动。在体外，ActA的肌动蛋白单体结合区域对于刺激Arp 2/3依赖的肌动蛋白成核是至关重要的;然而，该区域对于细胞中基于肌动蛋白的运动是不可或缺的。在这里，我们提供的遗传和生化证据表明，血管舒张刺激磷蛋白（VASP）招聘ActA可以绕过缺陷肌动蛋白单体结合。此外，纯化的VASP增强了野生型ActA和Arp 2/3复合物的肌动蛋白成核活性，同时还降低了肌动蛋白分支形成的频率。这些数据表明，ActA刺激Arp 2/3复合物的VASP依赖性和非依赖性的机制，产生不同的群体肌动蛋白丝的彗星尾巴L。单核细胞增多症。VASP促进肌动蛋白丝成核和调节肌动蛋白丝结构的能力突出了VASP在基于肌动蛋白的运动中的核心作用。
The Listeria monocytogenes ActA protein mediates actin-based motility by recruiting and stimulating the Arp2/3 complex. In vitro, the actin monomer-binding region of ActA is critical for stimulating Arp2/3-dependent actin nucleation; however, this region is dispensable for actin-based motility in cells. Here, we provide genetic and biochemical evidence that vasodilator-stimulated phosphoprotein (VASP) recruitment by ActA can bypass defects in actin monomer-binding. Furthermore, purified VASP enhances the actin-nucleating activity of wild-type ActA and the Arp2/3 complex while also reducing the frequency of actin branch formation. These data suggest that ActA stimulates the Arp2/3 complex by both VASP-dependent and -independent mechanisms that generate distinct populations of actin filaments in the comet tails of L. monocytogenes. The ability of VASP to contribute to actin filament nucleation and to regulate actin filament architecture highlights the central role of VASP in actin-based motility.