Polo-like kinase 1 (Plk1) is a mitotic serine/threonine kinase implicated in spindle formation and cytokinesis in mammalian cells. Here, purified Plk1 was found to bind to reconstituted microtubules in vitro. Further, Plk1 was found to co-localize with interphase microtubules in MCF-7 cells and to co-immunoprecipitate with polymerized tubulin. The binding of Plk1 to interphase microtubules appeared to increase with an increase in the level of tubulin acetylation in MCF-7 cells. Interestingly, Plk1 inhibitor III, an inhibitor of Plk1 kinase activity, treatment increased the association of Plk1 with the interphase microtubules in MCF-7 cells. Therefore, the effect of inhibition of Plk1 kinase activity on the dynamic instability of microtubules was determined by time-lapse imaging in MCF-7 cells. Plk1 inhibitor III dampened the dynamic instability of microtubules. For example, Plk1 inhibitor III (3 μM) reduced the rate and extent of the growing phase by 28 and 48%, respectively, and inhibited the dynamicity of microtubules by 53% as compared to the microtubules in control MCF-7 cells. Plk1 inhibitor III treatment also increased the level of acetylated microtubules, indicating that it stabilizes microtubules. The findings indicated that Plk1 interacts with microtubules and Plk1 may have a role in the regulation of microtubule dynamics.

中文翻译：

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马球样激酶1的抑制抑制MCF-7细胞中的微管动力学。

Polo样激酶1（Plk1）是一种有丝分裂的丝氨酸/苏氨酸激酶，与哺乳动物细胞的纺锤体形成和胞质分裂有关。在这里，发现纯化的Plk1在体外与重组微管结合。此外，发现Plk1与MCF-7细胞中的相间微管共定位，并与聚合的微管蛋白共免疫沉淀。Plk1与相间微管的结合似乎随着MCF-7细胞微管蛋白乙酰化水平的增加而增加。有趣的是，Plk1抑制剂III，一种Plk1激酶活性的抑制剂，治疗增加了Plk1与MCF-7细胞中相间微管的结合。因此，通过MCF-7细胞中的延时成像确定了抑制Plk1激酶活性对微管动态不稳定性的影响。Plk1抑制剂III减轻了微管的动态不稳定性。例如，与对照MCF-7细胞中的微管相比，Plk1抑制剂III（3μM）分别将生长期的速率和程度降低了28％和48％，并将微管的动态性抑制了53％。Plk1抑制剂III的治疗也增加了乙酰化微管的水平，表明它可以稳定微管。这些发现表明Plk1与微管相互作用，并且Plk1可能在微管动力学的调节中起作用。Plk1抑制剂III的治疗也增加了乙酰化微管的水平，表明它可以稳定微管。这些发现表明Plk1与微管相互作用，并且Plk1可能在微管动力学的调节中起作用。Plk1抑制剂III的治疗也增加了乙酰化微管的水平，表明它可以稳定微管。这些发现表明Plk1与微管相互作用，并且Plk1可能在微管动力学的调节中起作用。