Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany.
Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffen Strasse 7, 38124 Braunschweig, Germany.
J Cell Sci. 2020 Apr 9;133(7):jcs239020. doi: 10.1242/jcs.239020.
Efficient migration on adhesive surfaces involves the protrusion of lamellipodial actin networks and their subsequent stabilization by nascent adhesions. The actin-binding protein lamellipodin (Lpd) is thought to play a critical role in lamellipodium protrusion, by delivering Ena/VASP proteins onto the growing plus ends of actin filaments and by interacting with the WAVE regulatory complex, an activator of the Arp2/3 complex, at the leading edge. Using B16-F1 melanoma cell lines, we demonstrate that genetic ablation of Lpd compromises protrusion efficiency and coincident cell migration without altering essential parameters of lamellipodia, including their maximal rate of forward advancement and actin polymerization. We also confirmed lamellipodia and migration phenotypes with CRISPR/Cas9-mediated Lpd knockout Rat2 fibroblasts, excluding cell type-specific effects. Moreover, computer-aided analysis of cell-edge morphodynamics on B16-F1 cell lamellipodia revealed that loss of Lpd correlates with reduced temporal protrusion maintenance as a prerequisite of nascent adhesion formation. We conclude that Lpd optimizes protrusion and nascent adhesion formation by counteracting frequent, chaotic retraction and membrane ruffling.This article has an associated First Person interview with the first author of the paper.
在黏附表面上进行有效的迁移涉及片状伪足肌动蛋白网络的突出及其随后通过新形成的黏附物稳定。肌动蛋白结合蛋白片状蛋白（Lpd）被认为在片状伪足的突出中起着关键作用，通过将 Ena/VASP 蛋白递送到肌动蛋白丝的生长正端，并与 WAVE 调节复合物相互作用，该复合物是 Arp2/3 复合物的激活剂，位于前沿。使用 B16-F1 黑色素瘤细胞系，我们证明 Lpd 的遗传缺失会损害突起效率和伴随的细胞迁移，而不会改变片状伪足的基本参数，包括它们的最大前进速度和肌动蛋白聚合。我们还使用 CRISPR/Cas9 介导的 Lpd 敲除 Rat2 成纤维细胞证实了片状伪足和迁移表型，排除了细胞类型特异性效应。此外，对 B16-F1 细胞片状伪足的细胞边缘形态动力学的计算机辅助分析表明，Lpd 的缺失与减少新形成黏附物形成所需的暂时突起维持相关。我们得出结论，Lpd 通过抵消频繁的、混乱的回缩和细胞膜皱襞来优化突起和新形成的黏附物的形成。本文有一篇与论文第一作者的相关第一人称访谈。
