Dynactin is required for microtubule anchoring at centrosomes.
Dynactin is required for microtubule anchoring at centrosomes.
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DOI：
10.1083/jcb.147.2.321
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发表时间：
1999-10-18
影响因子：
7.8
通讯作者：
Schroer, T A
中科院分区：
文献类型：
--
作者：
Quintyne, N J;Gill, S R;Eckley, D M;Crego, C L;Compton, D A;Schroer, T A
多蛋白复合物动力蛋白激活蛋白（dynactin）是细胞质动力蛋白马达的一个组成部分，在体外和体内基于动力蛋白的运动中是必需的。在活细胞中，动力蛋白 - 动力蛋白激活蛋白相互作用受到干扰会严重阻碍有丝分裂纺锤体的组装，并且在减数分裂或有丝分裂细胞提取物中抑制或去除动力蛋白或动力蛋白激活蛋白会阻止微管聚集成纺锤体。在间期细胞中，动力蛋白 - 动力蛋白激活蛋白复合物受到干扰与内质网到高尔基体的运输受阻以及高尔基体和内体 - 溶酶体系统的重组相关，但此前对微管组织的影响尚未明确。为了探究这个问题，我们在培养的成纤维细胞中过表达了多种动力蛋白激活蛋白亚基。与动力蛋白结合有关的亚基对微管组织和中心体完整性都有影响。微管被重组成无聚焦的阵列。中心粒周围成分γ微管蛋白和动力蛋白激活蛋白从中心体丢失，但中心粒周蛋白的定位仍然存在。从中心体的微管成核过程相对正常，但此后不久微管就变得紊乱。一些（但不是所有）动力蛋白激活蛋白亚基的过表达也会影响内膜定位。这些数据表明，动力蛋白和动力蛋白激活蛋白在成纤维细胞的中心体微管组织中起重要作用，并为动力蛋白激活蛋白 - 货物相互作用提供了新的见解。
The multiprotein complex, dynactin, is an integral part of the cytoplasmic dynein motor and is required for dynein-based motility in vitro and in vivo. In living cells, perturbation of the dynein–dynactin interaction profoundly blocks mitotic spindle assembly, and inhibition or depletion of dynein or dynactin from meiotic or mitotic cell extracts prevents microtubules from focusing into spindles. In interphase cells, perturbation of the dynein–dynactin complex is correlated with an inhibition of ER-to-Golgi movement and reorganization of the Golgi apparatus and the endosome–lysosome system, but the effects on microtubule organization have not previously been defined. To explore this question, we overexpressed a variety of dynactin subunits in cultured fibroblasts. Subunits implicated in dynein binding have effects on both microtubule organization and centrosome integrity. Microtubules are reorganized into unfocused arrays. The pericentriolar components, γ tubulin and dynactin, are lost from centrosomes, but pericentrin localization persists. Microtubule nucleation from centrosomes proceeds relatively normally, but microtubules become disorganized soon thereafter. Overexpression of some, but not all, dynactin subunits also affects endomembrane localization. These data indicate that dynein and dynactin play important roles in microtubule organization at centrosomes in fibroblastic cells and provide new insights into dynactin–cargo interactions.