HSP70 colocalizes with PLK1 at the centrosome and disturbs spindle dynamics in cells arrested in mitosis by arsenic trioxide
HSP70 colocalizes with PLK1 at the centrosome and disturbs spindle dynamics in cells arrested in mitosis by arsenic trioxide
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DOI：
10.1007/s00204-014-1222-x
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发表时间：
2014-09-01
影响因子：
6.1
通讯作者：
Lee, Te-Chang
中科院分区：
文献类型：
--
作者：
Chen, Yu-Ju;Lai, Kuo-Chu;Lee, Te-Chang
热休克蛋白70（HSP 70）是Polo样激酶1（PLK 1）的底物，可阻止三氧化二砷（ATO）诱导的细胞有丝分裂停滞。在这里，我们报告说，热休克蛋白70参与ATO诱导的纺锤体伸长，干扰有丝分裂进程。我们的研究结果表明，HSP 70和PLK 1共定位在中心体在ATO逮捕的有丝分裂细胞。位于中心体的HSP 70被PLK 1磷酸化，其Ser（631）和Ser（633）被磷酸化。此外，与野生型HSP 70（wt）及其磷酸化模拟突变体（HSP 70（SS 631，633 DD））不同，HSP 70的磷酸化抗性突变体（HSP 70（SS 631，633 AA））未能定位于中心体。ATO诱导的纺锤体延长在过表达HSP 70的细胞（SS 631，633 AA）中被消除。相反，异位表达HSP 70（SS 631，633 DD）的细胞中的有丝分裂纺锤体比表达HSP 70（wt）或HSP 70（SS 631，633 AA）的细胞对诺考达唑诱导的解聚更具抗性。此外，PLK 1的抑制显着降低HSP 70磷酸化，诱导ATO-有丝分裂细胞凋亡的早期发作。两者合计，我们的研究结果表明，PLK 1介导的磷酸化和中心体定位的HSP 70可能会干扰纺锤体动力学和防止凋亡的ATO逮捕有丝分裂细胞。
Heat shock protein 70 (HSP70) has been shown to be a substrate of Polo-like kinase 1 (PLK1), and it prevents cells arrested in mitosis by arsenic trioxide (ATO) from dying. Here, we report that HSP70 participates in ATO-induced spindle elongation, which interferes with mitosis progression. Our results demonstrate that HSP70 and PLK1 colocalize at the centrosome in ATO-arrested mitotic cells. HSP70 located at the centrosome was found to be phosphorylated by PLK1 at Ser(631) and Ser(633). Moreover, unlike wild-type HSP70 (HSP70(wt)) and its phosphomimetic mutant (HSP70(SS631,633DD)), a phosphorylation-resistant mutant of HSP70 (HSP70(SS631,633AA)) failed to localize at the centrosome. ATO-induced spindle elongation was abolished in cells overexpressing HSP70(SS631,633AA). Conversely, mitotic spindles in cells ectopically expressing HSP70(SS631,633DD) were more resistant to nocodazole-induced depolymerization than in those expressing HSP70(wt) or HSP70(SS631,633AA). In addition, inhibition of PLK1 significantly reduced HSP70 phosphorylation and induced early onset of apoptosis in ATO-arrested mitotic cells. Taken together, our results indicate that PLK1-mediated phosphorylation and centrosomal localization of HSP70 may interfere with spindle dynamics and prevent apoptosis of ATO-arrested mitotic cells.