Human Spy1 promotes survival of mammalian cells following DNA damage.
Human Spy1 promotes survival of mammalian cells following DNA damage.
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DOI：
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发表时间：
2003-07
期刊：
影响因子：
11.2
通讯作者：
E. Barnes;L. Porter;J. Lenormand;R. Dellinger;D. Donoghue
中科院分区：
文献类型：
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作者：
E. Barnes;L. Porter;J. Lenormand;R. Dellinger;D. Donoghue
Speedy (Spy1) 是一种新型细胞周期调节因子，可结合并激活 cdk2，最初被鉴定为粟酒裂殖酵母 Rad1 缺陷的抑制因子。在这里，我们证明，在细胞对喜树碱、顺铂和羟基脲等基因毒性剂诱导的 DNA 损伤做出反应时，人 Spy1 的过度表达可增强哺乳动物细胞的活力。克隆存活试验和彗星试验也表明 Spy1 表达可增强 DNA 损伤后细胞的存活率。与 Spy1 在 DNA 损伤反应中发挥作用一致，内源性 Spy1 蛋白水平在喜树碱、顺铂或羟基脲诱导的 DNA 损伤中上调。我们发现 Spy1 可以在 DNA 损伤反应期间激活 cdk2，并且 cdk2 的显性失活形式的表达会覆盖受损细胞中 Spy1 的功能。最后，使用小干扰 RNA 消除内源性 Spy1 表达会导致细胞对 DNA 损伤过度敏感。总之，这些结果表明人类 Spy1 介导保护哺乳动物细胞免受 DNA 损伤。
Speedy (Spy1) is a novel cell cycle regulator that binds and activates cdk2, and was originally identified as a suppressor of Rad1 deficiency in Schizosaccharomyces pombe. Here we demonstrate that overexpression of human Spy1 enhances mammalian cell viability during cellular responses to DNA damage induced by genotoxic agents such as camptothecin, cisplatin, and hydroxyurea. Clonogenic survival assays and comet assays also show that Spy1 expression enhances cell survival after DNA damage. Consistent with Spy1 having a role in the DNA damage response, endogenous Spy1 protein levels are up-regulated in response to DNA damage induced by camptothecin, cisplatin, or hydroxyurea. We found that Spy1 can activate cdk2 during the DNA damage response and that expression of a dominant-negative form of cdk2 overrides Spy1 function in damaged cells. Lastly, ablation of endogenous Spy1 expression using small interference RNA results in hypersensitization of cells to DNA damage. Together, these results demonstrate that human Spy1 mediates protection of mammalian cells against DNA damage.