Two activators of microtubule-based vesicle transport.
Two activators of microtubule-based vesicle transport.
复制标题
两个基于微管的囊泡运输的激活剂。
DOI：
10.1083/jcb.115.5.1309
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发表时间：
1991-12
影响因子：
7.8
通讯作者：
Sheetz, M P
中科院分区：
文献类型：
--
作者：
Schroer, T A;Sheetz, M P
通过核苷酸依赖性微管亲和力纯化的细胞质动力蛋白具有显著的负末端定向囊泡运动活性，其随着每个进一步的纯化步骤而降低。高度纯化的动力蛋白使膜囊泡结合在微管上但不移动。我们利用这些观察结果，开发一种测定的因素，结合动力蛋白，将允许负端定向囊泡运动。在纯化的每个步骤中，将非动力蛋白级分与动力蛋白重组并测定囊泡运动性。用此方法鉴定了两个活性组分。一种称为Activator I，通过速度沉降与20S动力蛋白共纯化，但可以通过离子交换色谱法与其分离。激活剂I只增加动力蛋白驱动的囊泡运动的频率。激活剂II，沉积在9S，增加了囊泡运输的频率和速度，也支持加端运动。我们的研究结果表明，动力蛋白为基础的运动控制在多个水平，并提供了两个监管因素的初步表征。
Cytoplasmic dynein purified by nucleotide dependent microtubule affinity has significant minus end-directed vesicle motor activity that decreases with each further purification step. Highly purified dynein causes membrane vesicles to bind but not move on microtubules. We exploited these observations to develop an assay for factors that, in combination with dynein, would permit minus end-directed vesicle motility. At each step of the purification, non-dynein fractions were recombined with dynein and assayed for vesicle motility. Two activating fractions were identified by this method. One, called Activator I, copurified with 20S dynein by velocity sedimentation but could be separated from it by ion exchange chromatography. Activator I increased only the frequency of dynein-driven vesicle movements. Activator II, sedimenting at 9S, increased both the frequency and velocity of vesicle transport and also supported plus end movements. Our results suggest that dynein-based motility is controlled at multiple levels and provide a preliminary characterization of two regulatory factors.