Rodionov V I, Borisy G G
Laboratory of Molecular Biology, University of Wisconsin, Madison, WI 53706, USA.
Science. 1997 Jan 10;275(5297):215-8. doi: 10.1126/science.275.5297.215.
In vivo, cytoplasmic microtubules are nucleated and anchored by their minus ends at the centrosome and are believed to turn over by a mechanism termed dynamic instability: depolymerization and repolymerization at their plus ends. In cytoplasmic fragments of fish melanophores, microtubules were shown to detach from their nucleation site and depolymerize from their minus ends. Free microtubules moved toward the periphery by treadmilling-growth at one end and shortening from the opposite end. Frequent release from nucleation sites may be a general property of centrosomes and permit a minus-end mechanism of microtubule turnover and treadmilling.
在体内，细胞质微管由其负端在中心体处成核并锚定，据信通过一种称为动态不稳定性的机制进行周转：其正端的解聚和重新聚合。在鱼类黑素细胞的细胞质片段中，微管显示从其成核位点脱离并从其负端解聚。游离微管通过踏车运动向周边移动，一端生长而另一端缩短。频繁从成核位点释放可能是中心体的一个普遍特性，并允许微管周转和踏车运动的负端机制。
