Microtubule-dependent transport and dynamics of vimentin intermediate filaments.
Microtubule-dependent transport and dynamics of vimentin intermediate filaments.
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DOI：
10.1091/mbc.e14-09-1398
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发表时间：
2015-05-01
影响因子：
3.3
通讯作者：
Gelfand VI
中科院分区：
文献类型：
--
作者：
Hookway C;Ding L;Davidson MW;Rappoport JZ;Danuser G;Gelfand VI
波形蛋白中间体被认为是非常稳定的结构，实际上是非常动态的。纤维在细胞内沿沿着微管被积极运输。此外，长丝通过强力切断和再退火进行不断的重排，但从未完全分解和重新组装。我们研究了波形蛋白中间丝动力学的两个方面-丝的运输和亚基交换。我们观察运输的长丝在细胞的周边使用活细胞结构照明显微镜。我们研究了丝运输其他地方的细胞使用光转换波形蛋白探针和全内反射显微镜。我们发现，细丝迅速运输沿着线性轨道在顺行和逆行方向。细丝运输依赖于微管，但独立于微管聚合和/或与正末端结合蛋白APC的相互作用。我们还研究了光转换后的长期成像的丝亚基交换。我们发现，即使在光转换后分裂的细胞中，转换后的波形蛋白仍保持在沿着细丝长度的小簇中，而不是在整个网络中均匀地重新分布。这些数据表明，波形蛋白丝不分解成单独的亚基，他们重组切断和再退火。总之，这些结果表明，波形蛋白细丝是非常动态的，它们的运输是网络维护所必需的。
Vimentin intermediate filaments-structures that were considered extremely stable-are in fact very dynamic. Filaments are actively transported throughout the cell along microtubules. In addition, filaments undergo constant rearrangement by robust severing and reannealing but never completely disassemble and reassemble. We studied two aspects of vimentin intermediate filament dynamics—transport of filaments and subunit exchange. We observed transport of long filaments in the periphery of cells using live-cell structured illumination microscopy. We studied filament transport elsewhere in cells using a photoconvertible-vimentin probe and total internal reflection microscopy. We found that filaments were rapidly transported along linear tracks in both anterograde and retrograde directions. Filament transport was microtubule dependent but independent of microtubule polymerization and/or an interaction with the plus end–binding protein APC. We also studied subunit exchange in filaments by long-term imaging after photoconversion. We found that converted vimentin remained in small clusters along the length of filaments rather than redistributing uniformly throughout the network, even in cells that divided after photoconversion. These data show that vimentin filaments do not depolymerize into individual subunits; they recompose by severing and reannealing. Together these results show that vimentin filaments are very dynamic and that their transport is required for network maintenance.