Yeast actin patches are networks of branched actin filaments.
Yeast actin patches are networks of branched actin filaments.
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DOI：
10.1083/jcb.200404159
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发表时间：
2004-08-30
期刊：
影响因子：
--
通讯作者：
Bridgman PC
中科院分区：
文献类型：
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作者：
Young ME;Cooper JA;Bridgman PC
皮质肌动蛋白斑块是出芽和裂殖酵母中最突出的肌动蛋白结构。补丁可以快速组装、移动和拆卸。我们通过研究补片内的肌动蛋白丝超微结构来研究补片肌动蛋白组装和运动的机制。肌动蛋白斑块从酿酒酵母中部分纯化，并通过负染色电子显微镜 (EM) 检查。为了识别 EM 中的斑块，我们将 GFP 标记斑块的荧光和 EM 图像相关联。斑块包含肌动蛋白丝网络，具有 Arp2/3 复合体的分支特征。平均一块斑块包含 85 根细丝。平均细丝长度仅为 50 nm（20 个肌动蛋白亚基），细丝与分支之比为 3:1。缺乏 Sac6/fimbrin 的斑块不稳定，而缺乏加帽蛋白的斑块则相对正常。我们的结果与 Arp2/3 复合物介导的肌动蛋白聚合驱动酵母肌动蛋白贴片组装和运动一致，如树突成核模型的变体所描述的。
Cortical actin patches are the most prominent actin structure in budding and fission yeast. Patches assemble, move, and disassemble rapidly. We investigated the mechanisms underlying patch actin assembly and motility by studying actin filament ultrastructure within a patch. Actin patches were partially purified from Saccharomyces cerevisiae and examined by negative-stain electron microscopy (EM). To identify patches in the EM, we correlated fluorescence and EM images of GFP-labeled patches. Patches contained a network of actin filaments with branches characteristic of Arp2/3 complex. An average patch contained 85 filaments. The average filament was only 50-nm (20 actin subunits) long, and the filament to branch ratio was 3:1. Patches lacking Sac6/fimbrin were unstable, and patches lacking capping protein were relatively normal. Our results are consistent with Arp2/3 complex-mediated actin polymerization driving yeast actin patch assembly and motility, as described by a variation of the dendritic nucleation model.