The actin capping protein in Aspergillus nidulans enhances dynein function without significantly affecting Arp1 filament assembly.
The actin capping protein in Aspergillus nidulans enhances dynein function without significantly affecting Arp1 filament assembly.
复制标题
构巢曲霉中的肌动蛋白加帽蛋白可增强动力蛋白功能，但不会显着影响 Arp1 丝组装。
DOI：
10.1038/s41598-018-29818-4
复制
发表时间：
2018
影响因子：
4.6
通讯作者：
Xiang,Xin
中科院分区：
文献类型：
--
作者：
Zhang,Jun;Qiu,Rongde;Xiang,Xin
负端定向的微管运动细胞质动力蛋白需要动力蛋白复合物来实现体内功能。脊椎动物动力肌动蛋白复合物的骨架是Arp 1（肌动蛋白相关蛋白1）微丝，其倒刺末端与异二聚体肌动蛋白帽蛋白结合。然而，目前还不清楚加帽蛋白是否是低等真核生物中的dynactin组分，特别是因为它似乎不是芽殖酵母dynactin复合物的组分。在这里，我们的生化数据表明，帽蛋白是一个组成部分的dynactin复杂的丝状真菌Aspergillusnidulans。此外，编码帽蛋白α（capA）的基因的缺失导致核分布和早期内体转运（两个动力蛋白介导的过程）的缺陷。然而，这两个过程中的缺陷都没有动力蛋白重链突变体或动力蛋白的p25突变体所表现出的缺陷严重。此外，加帽蛋白的缺失不会显著影响动力蛋白Arp 1细丝的组装或动力蛋白-动力蛋白-HookC-HookA（HookinA.nidulans）复合物的形成。这些结果表明，真菌帽蛋白是不重要的Arp 1丝组装，但它的存在是需要增强动力蛋白功能在体内。
The minus-end-directed microtubule motor cytoplasmic dynein requires the dynactin complex forin vivofunctions. The backbone of the vertebrate dynactin complex is the Arp1 (actin-related protein 1) mini-filament whose barbed end binds to the heterodimeric actin capping protein. However, it is unclear whether the capping protein is a dynactin component in lower eukaryotic organisms, especially because it does not appear to be a component of the budding yeast dynactin complex. Here our biochemical data show that the capping protein is a component of the dynactin complex in the filamentous fungusAspergillus nidulans. Moreover, deletion of the gene encoding capping protein alpha (capA) results in a defect in both nuclear distribution and early-endosome transport, two dynein-mediated processes. However, the defect in either process is less severe than that exhibited by a dynein heavy chain mutant or the ∆p25 mutant of dynactin. In addition, loss of capping protein does not significantly affect the assembly of the dynactin Arp1 filament or the formation of the dynein-dynactin-∆C-HookA (Hook inA.nidulans) complex. These results suggest that fungal capping protein is not important for Arp1 filament assembly but its presence is required for enhancing dynein functionin vivo.