MINUS-END-DIRECTED MOTION OF KINESIN-COATED MICROSPHERES DRIVEN BY MICROTUBULE DEPOLYMERIZATION
MINUS-END-DIRECTED MOTION OF KINESIN-COATED MICROSPHERES DRIVEN BY MICROTUBULE DEPOLYMERIZATION
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DOI：
10.1038/373161a0
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发表时间：
1995-01-12
期刊：
影响因子：
64.8
通讯作者：
MCINTOSH, JR
中科院分区：
文献类型：
--
作者：
LOMBILLO, VA;STEWART, RJ;MCINTOSH, JR
长期以来，人们一直认为微管 (MT) 长度的动态变化有助于细胞内运动 (1)。微管蛋白的聚合 (2) 和解聚 (3-5) 均已被证明在体外起作用，但移动物体（例如染色体）的生化复杂性使将 MT 动力学与运动耦合的蛋白质的识别变得复杂。对从裂解的四膜虫表膜中生长并附着在其上的 MT 进行的研究表明，体外染色体的拆卸依赖性运动可以通过针对驱动蛋白运动结构域的抗体来抑制 (6)。为了研究可以在拆卸依赖性运动中发挥作用的蛋白质，我们改进了这种运动测定，用蛋白质包被的乳胶微球代替染色体。我们在这里报告了几种酶（包括驱动蛋白）在分解 Mts 时支持乳胶微球体外运动的能力（图 1a）。驱动蛋白运动活性的极性可以通过 MT 分解来逆转，并且运动和 MT 末端之间的相互作用可以减慢或加快微管蛋白解聚的速度。
DYNAMIC changes in microtubule (MT) length have long been thought to contribute to intracellular motility(1). Both the polymerization(2) and depolymerization(3-5) of tubulin have been shown to do work in vitro, but the biochemical complexity of objects moved, such as chromosomes, has complicated the identification of proteins that couple MT dynamics with motility. Work with MTs grown from and tethered to pellicles of lysed Tetrahymena has shown that disassembly-dependent movement of chromosomes in vitro can be inhibited with antibodies against the motor domain of kinesin(6). To study proteins that can function in disassembly-dependent motion, we have refined this motility assay, replacing chromosomes with protein-coated latex microspheres. We report here the ability of several enzymes, including kinesin, to support in vitro motility of latex microspheres on disassembling Mts (Fig. 1a). The polarity of kinesin's motor activity can be reversed by MT disassembly and interactions between a motor and a MT end can either slow or speed the rate of tubulin depolymerization.