Rapid movements of vimentin on microtubule tracks: kinesin-dependent assembly of intermediate filament networks.
Rapid movements of vimentin on microtubule tracks: kinesin-dependent assembly of intermediate filament networks.
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DOI：
10.1083/jcb.143.1.159
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发表时间：
1998-10-05
影响因子：
7.8
通讯作者：
Goldman, R D
中科院分区：
文献类型：
--
作者：
Prahlad, V;Yoon, M;Moir, R D;Vale, R D;Goldman, R D
成纤维细胞中延伸的中间丝（IF）网络的组装和维持需要微管（MT）的完整性。利用绿色荧光蛋白-波形蛋白构建体，并将BHK-21细胞作为模型系统来研究IF-MT相互作用，我们发现了波形蛋白IF细胞骨架组装的新机制。这需要IF前体向细胞质的外周区域快速、不连续和MT依赖性的运动，在那里它们似乎组装成短纤维。这些前体或波形蛋白点以平均0.55 ± 0.24 μm/s的速度移动。波形蛋白点与MT共定位，用诺考达唑处理后，它们的运动性受到抑制。我们的研究进一步暗示了一种传统的驱动蛋白在波形蛋白点的运动中。点共定位与传统的驱动蛋白所示的间接免疫荧光，和IF制剂从铺展细胞富集驱动蛋白。此外，将驱动蛋白抗体显微注射到扩展细胞中可以防止扩展IF网络的组装。这些研究为IF和MT系统之间的相互作用提供了见解。他们还建议传统的驱动蛋白在非膜蛋白货物的分布，和IF组装的局部调节的作用。
The assembly and maintenance of an extended intermediate filament (IF) network in fibroblasts requires microtubule (MT) integrity. Using a green fluorescent protein–vimentin construct, and spreading BHK-21 cells as a model system to study IF–MT interactions, we have discovered a novel mechanism involved in the assembly of the vimentin IF cytoskeleton. This entails the rapid, discontinuous, and MT-dependent movement of IF precursors towards the peripheral regions of the cytoplasm where they appear to assemble into short fibrils. These precursors, or vimentin dots, move at speeds averaging 0.55 ± 0.24 μm/s. The vimentin dots colocalize with MT and their motility is inhibited after treatment with nocodazole. Our studies further implicate a conventional kinesin in the movement of the vimentin dots. The dots colocalize with conventional kinesin as shown by indirect immunofluorescence, and IF preparations from spreading cells are enriched in kinesin. Furthermore, microinjection of kinesin antibodies into spreading cells prevents the assembly of an extended IF network. These studies provide insights into the interactions between the IF and MT systems. They also suggest a role for conventional kinesin in the distribution of non-membranous protein cargo, and the local regulation of IF assembly.