King Stephen J, Brown Christa L, Maier Kerstin C, Quintyne Nicholas J, Schroer Trina A
Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
Mol Biol Cell. 2003 Dec;14(12):5089-97. doi: 10.1091/mbc.e03-01-0025. Epub 2003 Oct 17.
Cytoplasmic dynein and dynactin are megadalton-sized multisubunit molecules that function together as a cytoskeletal motor. In the present study, we explore the mechanism of dynein-dynactin binding in vitro and then extend our findings to an in vivo context. Solution binding assays were used to define binding domains in the dynein intermediate chain (IC) and dynactin p150Glued subunit. Transient overexpression of a series of fragments of the dynein IC was used to determine the importance of this subunit for dynein function in mammalian tissue culture cells. Our results suggest that a functional dynein-dynactin interaction is required for proper microtubule organization and for the transport and localization of centrosomal components and endomembrane compartments. The dynein IC fragments have different effects on endomembrane localization, suggesting that different endomembranes may bind dynein via distinct mechanisms.
胞质动力蛋白和动力蛋白激活蛋白是兆道尔顿大小的多亚基分子，它们作为细胞骨架马达共同发挥作用。在本研究中，我们在体外探索动力蛋白 - 动力蛋白激活蛋白的结合机制，然后将我们的发现扩展到体内环境。溶液结合试验用于确定动力蛋白中间链（IC）和动力蛋白激活蛋白p150Glued亚基中的结合结构域。通过瞬时过表达动力蛋白IC的一系列片段来确定该亚基对哺乳动物组织培养细胞中动力蛋白功能的重要性。我们的结果表明，功能性动力蛋白 - 动力蛋白激活蛋白相互作用对于正确的微管组织以及中心体成分和内膜区室的运输和定位是必需的。动力蛋白IC片段对内膜定位有不同影响，表明不同的内膜可能通过不同机制结合动力蛋白。
