Molecular mechanisms of kinetochore capture by spindle microtubules
Molecular mechanisms of kinetochore capture by spindle microtubules
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DOI：
10.1038/nature03483
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发表时间：
2005-04-21
期刊：
影响因子：
64.8
通讯作者：
Tanaka, TU
中科院分区：
文献类型：
--
作者：
Tanaka, K;Mukae, N;Tanaka, TU
对于高保真的染色体分离，动粒必须被纺锤体微管正确捕获，但最初动粒捕获的机制仍然难以捉摸。在这里，我们通过调节着丝粒的活性，在酿酒酵母中可视化了个体着丝粒-微管的相互作用。动点被从纺锤体极点延伸出来的微管捕获，然后沿着它们向极地输送。微管从纺锤体极点延伸需要微管+末端跟踪蛋白和RAN GDP/GTP交换因子。不同的动粒成分用于微管对动粒的捕获，并确保随后的姐妹动粒在纺锤体上双向定位。Kar3是Kinesin-14家族的成员，是促进捕获的动蛋白沿微管运输的调节器之一。在这样的运输过程中，动粒通过促进微管从收缩到生长的转化，确保它们不会从相关的微管上滑落。这种转换是由Stu2从捕获的动点到微管的正端的运输促进的。
For high-fidelity chromosome segregation, kinetochores must be properly captured by spindle microtubules, but the mechanisms underlying initial kinetochore capture have remained elusive. Here we visualized individual kinetochore-microtubule interactions in Saccharomyces cerevisiae by regulating the activity of a centromere. Kinetochores are captured by the side of microtubules extending from spindle poles, and are subsequently transported poleward along them. The microtubule extension from spindle poles requires microtubule plus-end-tracking proteins and the Ran GDP/GTP exchange factor. Distinct kinetochore components are used for kinetochore capture by microtubules and for ensuring subsequent sister kinetochore bi-orientation on the spindle. Kar3, a kinesin-14 family member, is one of the regulators that promote transport of captured kinetochores along microtubules. During such transport, kinetochores ensure that they do not slide off their associated microtubules by facilitating the conversion of microtubule dynamics from shrinkage to growth at the plus ends. This conversion is promoted by the transport of Stu2 from the captured kinetochores to the plus ends of microtubules.