Stathmin and microtubules regulate mitotic entry in HeLa cells by controlling activation of both Aurora kinase A and Plk1.
Stathmin and microtubules regulate mitotic entry in HeLa cells by controlling activation of both Aurora kinase A and Plk1.
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Stathmin 和微管通过控制 Aurora 激酶 A 和 Plk1 的激活来调节 HeLa 细胞的有丝分裂进入。
DOI：
10.1091/mbc.e13-02-0108
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发表时间：
2013
影响因子：
3.3
通讯作者：
Cassimeris,Lynne
中科院分区：
文献类型：
--
作者：
Silva,VictoriaC;Cassimeris,Lynne
耗尽stathmin，微管（MT）去稳定剂，延迟有丝分裂进入HeLa细胞的104小时。Stathmin耗竭降低了CDC 25及其上游激活剂Aurora A和Plk 1的活性。Aurora A和Plk 1的化学抑制足以延迟有丝分裂进入4小时，而单独抑制任一激酶不会导致延迟。Aurora A和Plk 1可能在stathmin的下游受到调节，因为stathmin敲低和Aurora A和Plk 1抑制的组合不是累加的，并且再次延迟有丝分裂进入4小时。Aurora A定位于中心体需要MT，而stathmin缺失使其定位超出γ-微管蛋白，表明Aurora A激活的MT依赖性调节。Plk 1被抑制过量stathmin，检测在体外试验和细胞过表达stathmin青色荧光蛋白。在stathmin缺失的细胞中，Plk 1向中心体的募集被延迟，独立于MT。已经表明，用诺考达唑解聚MT消除了stathmin耗竭诱导的细胞周期延迟;在这项研究中，用诺考达唑解聚使Plk 1活性恢复到接近正常水平，表明MT也有助于Plk 1活化。这些数据表明，stathmin调节有丝分裂进入，部分通过MT，控制定位和激活的极光A和Plk 1。
Depletion of stathmin, a microtubule (MT) destabilizer, delays mitotic entry by ∼4 h in HeLa cells. Stathmin depletion reduced the activity of CDC25 and its upstream activators, Aurora A and Plk1. Chemical inhibition of both Aurora A and Plk1 was sufficient to delay mitotic entry by 4 h, while inhibiting either kinase alone did not cause a delay. Aurora A and Plk1 are likely regulated downstream of stathmin, because the combination of stathmin knockdown and inhibition of Aurora A and Plk1 was not additive and again delayed mitotic entry by 4 h. Aurora A localization to the centrosome required MTs, while stathmin depletion spread its localization beyond that of γ-tubulin, indicating an MT-dependent regulation of Aurora A activation. Plk1 was inhibited by excess stathmin, detected in in vitro assays and cells overexpressing stathmin–cyan fluorescent protein. Recruitment of Plk1 to the centrosome was delayed in stathmin-depleted cells, independent of MTs. It has been shown that depolymerizing MTs with nocodazole abrogates the stathmin-depletion induced cell cycle delay; in this study, depolymerization with nocodazole restored Plk1 activity to near normal levels, demonstrating that MTs also contribute to Plk1 activation. These data demonstrate that stathmin regulates mitotic entry, partially via MTs, to control localization and activation of both Aurora A and Plk1.