The mitotic kinesin-14 Ncd drives directional microtubule-microtubule sliding
The mitotic kinesin-14 Ncd drives directional microtubule-microtubule sliding
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DOI：
10.1038/ncb1877
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发表时间：
2009-06-01
影响因子：
21.3
通讯作者：
Diez, Stefan
中科院分区：
文献类型：
--
作者：
Fink, Gero;Hajdo, Lukasz;Diez, Stefan
在有丝分裂和减数分裂期间，双极纺锤体通过微管滑动以及微管生长和收缩促进染色体分离（1）。驱动蛋白-14是参与的马达之一，在缺乏驱动蛋白-5的情况下引起纺锤体塌陷（参考文献2，3），参与纺锤体组装（4）并调节纺锤体长度（5）。然而，这些活动的分子机制尚不清楚。在这里，我们报告说，果蝇驱动蛋白-14（Ncd）单独导致滑动的反平行微管，但锁在一起（即静态交联）那些是平行的。使用单分子成像，我们表明Ncd以尾部依赖性方式沿着微管扩散，并在滑动微管之间切换其方向。我们的研究结果表明，驱动蛋白-14导致滑动和扩展的反平行微管阵列的动态相互作用，通过电机域的一侧和尾部域的其他。这一机制解释了驱动蛋白14在纺锤体组织中的作用。
During mitosis and meiosis, the bipolar spindle facilitates chromosome segregation through microtubule sliding as well as microtubule growth and shrinkage(1). Kinesin-14, one of the motors involved, causes spindle collapse in the absence of kinesin-5 (refs 2, 3), participates in spindle assembly(4) and modulates spindle length(5). However, the molecular mechanisms underlying these activities are not known. Here, we report that Drosophila melanogaster kinesin-14 (Ncd) alone causes sliding of anti-parallel microtubules but locks together (that is, statically crosslinks) those that are parallel. Using single molecule imaging we show that Ncd diffuses along microtubules in a tail-dependent manner and switches its orientation between sliding microtubules. Our results show that kinesin-14 causes sliding and expansion of an anti-parallel microtubule array by dynamic interactions through the motor domain on the one side and the tail domain on the other. This mechanism accounts for the roles of kinesin-14 in spindle organization.