Asymmetric CLASP-dependent nucleation of noncentrosomal microtubules at the trans-Golgi network
Asymmetric CLASP-dependent nucleation of noncentrosomal microtubules at the trans-Golgi network
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DOI：
10.1016/j.devcel.2007.04.002
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发表时间：
2007-06-01
影响因子：
11.8
通讯作者：
Kaverina, Irina
中科院分区：
文献类型：
--
作者：
Efimov, Andrey;Kharitonov, Alexey;Kaverina, Irina
微管阵列的适当组织对于细胞内运输和细胞运动是必不可少的。一般认为，脊椎动物体细胞中的大多数（如果不是全部）微管是由中心体形成的。在这里，我们证明了大量的微管在未经处理的人类细胞起源于高尔基体在一个中心体独立的方式。中心体和高尔基体发出的微管都需要γ-微管蛋白来成核。此外，在高尔基体形成微管需要CLASP，选择性地包被非中心体微管种子的微管结合蛋白。我们发现，CLASP被招募到高尔基体周围的反式高尔基体网络（TGN）的TGN蛋白GCC 185。与放射状中心体阵列形成鲜明对比的是，在运动细胞中，在外周高尔基体室成核的微管优先朝向前缘。我们建议，高尔基体发出的微管有助于在极化细胞中的不对称微管网络，并支持不同的过程，包括后高尔基体运输到细胞前。
Proper organization of microtubule arrays is essential for intracellular trafficking and cell motility. It is generally assumed that most if not all microtubules in vertebrate somatic cells are formed by the centrosome. Here we demonstrate that a large number of microtubules in untreated human cells originate from the Golgi apparatus in a centrosome-independent manner. Both centrosomal and Golgi-emanating microtubules need gamma-tubulin for nucleation. Additionally, formation of microtubules at the Golgi requires CLASPs, microtubule-binding proteins that selectively coat noncentrosomal microtubule seeds. We show that CLASPs are recruited to the trans-Golgi network (TGN) at the Golgi periphery by the TGN protein GCC185. In sharp contrast to radial centrosomal arrays, microtubules nucleated at the peripheral Golgi compartment are preferentially oriented toward the leading edge in motile cells. We propose that Golgi-emanating microtubules contribute to the asymmetric microtubule networks in polarized cells and support diverse processes including post-Golgi transport to the cell front.