Inhibition of Aurora A in response to DNA damage
Inhibition of Aurora A in response to DNA damage
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DOI：
10.1038/sj.onc.1209056
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发表时间：
2006-01-01
期刊：
影响因子：
8
通讯作者：
Ferrari, S
中科院分区：
文献类型：
--
作者：
Krystyniak, A;Garcia-Echeverria, C;Ferrari, S
有丝分裂激酶是感知基因毒性损伤和影响细胞周期机制的途径的最终目标。在这里，我们提供了 Aurora A (AurA) 在 DNA 双链断裂产生时受到抑制的证据。我们证明 AurA 不是 CDK1 的下游，并且 DNA 损伤对 AurA 和 CDK1 的抑制是独立发生的。使用 Chk2（一种选择性 Chk1 抑制剂）功能缺陷的细胞系和 Chk1 的 siRNA，我们发现 DNA 损伤信号通过 Chk1 依赖性途径传递至 AurA。关于AurA抑制的分子机制，我们发现点突变Ser342 > Ala使得AurA能够抵抗DNA损伤的抑制。通过两种不同的方法，我们检查了 DNA 损伤细胞中 AurA 活性重建的影响：（i）野生型和 Ser342 > Ala 突变体的瞬时表达，但不是激酶死亡，AurA 导致绕过 DNA 损伤阻断； (ii)在诱导DNA损伤导致有丝分裂进入后，将高活性wt-AurA直接转导至G2停滞细胞中。我们发现 AurA 进入有丝分裂的机制是 CDK1 的重新激活，从而表明 AurA 在 CDK1 上游发挥着关键作用。提出了一个模型，描述 AurA 在有丝分裂开始和 DNA 损伤时可能发挥的作用。
Mitotic kinases are the ultimate target of pathways sensing genotoxic damage and impinging on the cell cycle machinery. Here, we provide evidence that Aurora A (AurA) was inhibited upon generation of double-strand breaks in DNA. We demonstrate that AurA was not downstream of CDK1 and that inhibition of AurA and CDK1 by DNA damage occurred independently. Using a cell line functionally deficient in Chk2, a selective Chk1 inhibitor and siRNA to Chk1, we show that DNA-damage signals were delivered to AurA through a Chk1-dependent pathway. With regard to the molecular mechanism of AurA inhibition, we found that the point mutation Ser342 > Ala rendered AurA resistant to inhibition by DNA damage. By means of two distinct approaches we examined the impact of reconstitution of AurA activity in DNA-damaged cells: (i) transient expression of wild-type and Ser342 > Ala mutant, but not kinase-dead, AurA led to bypass of the DNA damage block; (ii) direct transduction of highly active wt-AurA into G2 arrested cells precisely after induction of DNA damage resulted in mitotic entry. We show that the mechanism through which AurA allowed entry into mitosis was reactivation of CDK1, thus indicating that AurA plays a key role upstream of CDK1. A model depicting the possible role of AurA at the onset of mitosis and upon DNA damage is presented.