Microtubule release from the centrosome
Microtubule release from the centrosome
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DOI：
10.1073/pnas.94.10.5078
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发表时间：
1997-05-13
影响因子：
11.1
通讯作者：
Borisy, GG
中科院分区：
文献类型：
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作者：
Keating, TJ;Peloquin, JG;Borisy, GG
虽然微管通常被认为起源于中心体，但许多细胞类型都有大量的微管，没有明显的中心体连接，但这些非中心体微管的起源尚不清楚，我们应用体内微管形成的动力学分析来建立它们的起源模式。时间推移荧光显微镜显示，培养上皮细胞中的非中心体微管主要是通过中心体的结构性成核和释放而产生的。释放后，MTS远离中心体，趋于解聚。激光标记实验表明，释放的MTS单独运动，其正端领先，提示它们是由负端定向马达运输的，释放的MTS是动态的；激光标记实验表明，释放的MTS的正端生长、停顿或缩短，而负端稳定或缩短，微管释放可能具有两种细胞功能，释放和运输可以产生在上皮细胞、神经元和其他不对称、分化的细胞中观察到的非中心体MT阵列，释放也通过暴露MT负端而促进聚合物的周转，从而为亚单位的丢失提供额外的位置，非中心体群体可能反映了中心体核形成、释放、稳定的状态和动态感。
Although microtubules (MTs) are generally thought to originate at the centrosome, a number of cell types have significant populations of MTs with no apparent centrosomal connection, The origin of these noncentrosomal MTs has been unclear, We applied kinetic analysis of MT formation in vivo to establish their mode of origin, Time-lapse fluorescence microscopy demonstrated that noncentrosomal MTs in cultured epithelial cells arise primarily by constitutive nucleation at, and release from, the centrosome. After release, MTs moved away from the centrosome and tended to depolymerize. Laser-marking experiments demonstrated that released MTs moved individually with their plus ends leading, suggesting that they were transported by minus end-directed motors, Released MTs were dynamic, The laser marking experiments demonstrated that plus ends of released MTs grew, paused, or shortened while the minus ends were stable or shortened, Microtubule release may serve two kinds of cellular function, Release and transport could generate the noncentrosomal MT arrays observed in epithelial cells, neurons, and other asymmetric, differentiated cells, Release would also contribute to polymer turnover by exposing MT minus ends, thereby providing additional sites for loss of subunits, The noncentrosomal population of MTs may reflect a steady-state of centrosomal nucleation, release, and dynamics.