Motility determinants in WASP family proteins
Motility determinants in WASP family proteins
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DOI：
10.1091/mbc.e02-05-0294
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发表时间：
2002-11-01
影响因子：
3.3
通讯作者：
Welch, MD
中科院分区：
文献类型：
--
作者：
Yarar, D;D'Alessio, JA;Welch, MD
响应于上游信号，Wiskott-Aldrich综合征蛋白（WASP）家族中的蛋白质通过Arp 2/3复合物调节肌动蛋白成核。尽管深入研究了WASP家族蛋白在成核中的功能，但尚未了解它们独特的结构组织如何有助于肌动蛋白的运动。在此，我们分析了WASP和Scar 1截断衍生物的活动，通过使用基于珠的运动性测定。WASP足以指导运动的最小区域是C-末端WCA片段，而Scar 1的相应区域不足。此外，WASP和Scar 1的富含脯氨酸的区域和WASP的Ena/VASP同源1（EVH 1）结构域独立地增强运动率。这些地区的运动的贡献不能占其直接影响肌动蛋白成核与Arp 2/3复合物，这表明他们刺激运动招募额外的因素。我们已经确定profilin作为这样一个因素。WASP和Scar 1包被的珠运动率显着降低的轮廓蛋白和VASP的耗尽，可以更有效地拯救VASP和野生型轮廓蛋白的组合比VASP和突变体轮廓蛋白，不能结合富含脯氨酸的序列。此外，WASP WCA珠的运动性不受VASP和profilin的耗尽或添加的影响。我们的研究结果表明，招聘的因素，包括profilin，由富含脯氨酸的地区WASP和Scar 1和EVH 1域的WASP刺激细胞肌动蛋白为基础的运动。
In response to upstream signals, proteins in the Wiskott-Aldrich Syndrome protein (WASP) family regulate actin nucleation via the Arp2/3 complex. Despite intensive study of the function of WASP family proteins in nucleation, it is not yet understood how their distinct structural organization contributes to actin-based motility. Herein, we analyzed the activities of WASP and Scar1 truncation derivatives by using a bead-based motility assay. The minimal region of WASP sufficient to direct movement was the C-terminal WCA fragment, whereas the corresponding region of Scar1 was insufficient. In addition, the proline-rich regions of WASP and Scar1 and the Ena/VASP homology 1 (EVH1) domain of WASP independently enhanced motility rates. The contributions of these regions to motility could not be accounted for by their direct effects on actin nucleation with the Arp2/3 complex, suggesting that they stimulate motility by recruiting additional factors. We have identified profilin as one such factor. WASP- and Scar1-coated bead motility rates were significantly reduced by depletion of profilin and VASP and could be more efficiently rescued by a combination of VASP and wild-type profilin than by VASP and a mutant profilin that cannot bind proline-rich sequences. Moreover, motility of WASP WCA beads was not affected by the depletion or addback of VASP and profilin. Our results suggest that recruitment of factors, including profilin, by the proline-rich regions of WASP and Scar1 and the EVH1 domain of WASP stimulates cellular actin-based motility.