Arp2/3 complex inhibition radically alters lamellipodial actin architecture, suspended cell shape, and the cell spreading process.
Arp2/3 complex inhibition radically alters lamellipodial actin architecture, suspended cell shape, and the cell spreading process.
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DOI：
10.1091/mbc.e14-07-1244
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发表时间：
2015-03-01
影响因子：
3.3
通讯作者：
Shuster CB
中科院分区：
文献类型：
--
作者：
Henson JH;Yeterian M;Weeks RM;Medrano AE;Brown BL;Geist HL;Pais MD;Oldenbourg R;Shuster CB
基于药物的Arp2/3抑制海胆腔母细胞的后果包括板足结构的剧烈变化，悬浮细胞的板足到丝状形状的变化，以及扩散细胞中新的肌动蛋白结构组织。Arp2/3抑制引起的肌动蛋白弧的产生被双胍抑制所阻止。最近的研究通过实验降低肌动蛋白丝成核器和分支前体Arp2/3复合物的活性来研究细胞边缘板足区（LP）的树突状肌动蛋白细胞骨架。在这里，我们通过药物抑制海胆腔母细胞中的Arp2/3复合物来扩展这些研究，这些细胞具有异常宽的LP区域，并相应地显示出夸大的向心流动。通过光镜和电子显微镜，我们证明了通过药物CK666抑制Arp2/3复合物显著改变LP肌动蛋白结构，减缓向心流动，驱动悬浮细胞板状向丝状形状变化，并在细胞扩散过程中诱导新的肌动蛋白结构组织。在体腔细胞中，CK666表型的一个普遍特征是横向肌动蛋白弧线，弧线的产生被双胍抑制剂阻止。我们还证明CK666处理在其他具有宽LP区域的细胞中产生肌动蛋白弧，即鱼角化细胞和果蝇S2细胞。我们假设，通过抑制Arp2/3复合物在体腔细胞中可见的肌动蛋白弧线可能代表了伸长的母丝的夸张表现，而母丝可能作为树突状肌动蛋白网络产生的支架。
The consequences of drug-based Arp2/3 inhibition in sea urchin coelomocytes include dramatic changes in lamellipodial architecture, a lamellipodial-to-filopodial shape change in suspended cells, and a novel actin structural organization in spreading cells. The generation of actin arcs induced by Arp2/3 inhibition is arrested by formin inhibition. Recent studies have investigated the dendritic actin cytoskeleton of the cell edge's lamellipodial (LP) region by experimentally decreasing the activity of the actin filament nucleator and branch former, the Arp2/3 complex. Here we extend these studies via pharmacological inhibition of the Arp2/3 complex in sea urchin coelomocytes, cells that possess an unusually broad LP region and display correspondingly exaggerated centripetal flow. Using light and electron microscopy, we demonstrate that Arp2/3 complex inhibition via the drug CK666 dramatically altered LP actin architecture, slowed centripetal flow, drove a lamellipodial-to-filopodial shape change in suspended cells, and induced a novel actin structural organization during cell spreading. A general feature of the CK666 phenotype in coelomocytes was transverse actin arcs, and arc generation was arrested by a formin inhibitor. We also demonstrate that CK666 treatment produces actin arcs in other cells with broad LP regions, namely fish keratocytes and Drosophila S2 cells. We hypothesize that the actin arcs made visible by Arp2/3 complex inhibition in coelomocytes may represent an exaggerated manifestation of the elongate mother filaments that could possibly serve as the scaffold for the production of the dendritic actin network.