Activation of Cdc2/cyclin B and inhibition of centrosome amplification in cells depleted of Plk1 by siRNA
Activation of Cdc2/cyclin B and inhibition of centrosome amplification in cells depleted of Plk1 by siRNA
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DOI：
10.1073/pnas.132269599
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发表时间：
2002-06-25
影响因子：
11.1
通讯作者：
Erikson, RL
中科院分区：
文献类型：
--
作者：
Liu, XQ;Erikson, RL
细胞周期的事件，即细胞增殖和分裂的阶段，由多个信号通路促进和控制。在众多参与这些过程的调节酶中，有一种是类似Polo的激酶(PLK)。据报道，Plks参与了多种有丝分裂过程，包括双极纺锤体的形成、CDC25C的激活、肌动蛋白环的形成、中心体的成熟和后期促进复合体的激活。为了进一步研究Plk1在哺乳动物细胞中的功能，我们使用了最近发展起来的小干扰RNA技术来特异性地耗尽培养细胞中的Plk1。我们发现Plk1缺失会导致CDC2蛋白激酶活性升高，从而抑制细胞周期进程。在经Plk1小干扰RNA处理的细胞中，约45%的细胞显示形成哑铃状的DNA组织，这表明姐妹染色单体并未完全分离。约15%的细胞确实完成了后期分裂，但没有完成胞质分裂。最后，Plk1缺失显著减少了羟基脲处理的U2OS细胞的中心体扩增。这些数据提供了直接证据，表明PLK在哺乳动物细胞的多个有丝分裂过程中是必需的，并讨论了它们的意义。
The events of the cell cycle, the stages at which the cell proliferates and divides, are facilitated and controlled by multiple signaling pathways. Among the many regulatory enzymes that contribute to these processes is the polo-like kinase (Plk). Plks have been reported to mediate multiple mitotic processes, including bipolar spindle formation, activation of Cdc25C, actin ring formation, centrosome maturation, and activation of the anaphase-promoting complex. To investigate its functions in mammalian cells further, we used the recently developed small interfering RNA technique specifically to deplete Plk1 in cultured cells. We find that Plk1 depletion results in elevated Cdc2 protein kinase activity and thus attenuates cell-cycle progression. About 45% of cells treated with Plk1 small interfering RNA show the formation of a dumbbell-like DNA organization, suggesting that sister chromatids are not completely separated. About 15% of these cells do complete anaphase but do not complete cytokinesis. Finally, Plk1 depletion significantly reduces centrosome amplification in hydroxyurea-treated U2OS cells. These data provide direct evidence that Plk is required for multiple mitotic processes in mammalian cells and their significance is discussed.