Induction and utilization of an ATM signaling pathway by polyomavirus
Induction and utilization of an ATM signaling pathway by polyomavirus
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DOI：
10.1128/jvi.79.20.13007-13017.2005
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发表时间：
2005-10-01
影响因子：
5.4
通讯作者：
Benjamin, TL
中科院分区：
文献类型：
--
作者：
Dahl, J;You, J;Benjamin, TL
从G1到S的进展是多瘤病毒DNA复制所必需的，并且依赖于大T与视网膜母细胞瘤基因产物pRb的相互作用。这种病毒诱导的复制途径伴随着类似于DNA损伤反应的p53活化（12）。我们试图确定这一途径是否部分依赖于ATM（共济失调毛细血管扩张突变）激酶的激活，以及病毒是否从这一途径中获得超越进入S.我们发现，多瘤病毒感染激活的S-和G（2）-阶段的检查点在原代以及建立小鼠细胞。与未感染的血清刺激的细胞相比，感染的细胞经历延长的S期，并且在裂解性死亡之前没有显示G（2）-> M转变的证据。感染伴随着体外ATM活性和体内ATM-S1981-P水平的增加。将感染的细胞与咖啡因（一种已知的ATM抑制剂）一起孵育，并不能阻止病毒进入S，但与细胞DNA合成相比，降低了病毒的速率。重要的是，咖啡因平均降低病毒DNA的产量3至6倍，感染性病毒的产量高达10倍。在ATM（-/-）P53（-/-）中的病毒产量比在ATM（+/+）P53（-/-）小鼠胚胎成纤维细胞中低10倍，表明ATM在生产性感染中的p53非依赖性作用。用其磷酸化突变体SMC 1（S957 AS 966 A）取代正常SMC 1（染色体结构维持蛋白或粘着蛋白）蛋白（DNA修复途径中的关键ATM底物）也使病毒产量降低了约90%。我们认为多瘤病毒激活并利用DNA修复ATM途径的一个组分来延长S期并帮助其自身复制。
Progression from G, to S is essential for polyomavirus DNA replication and depends on the interaction of large T with the retinoblastoma gene product pRb. This virus-induced replication pathway is accompanied by p53 activation resembling a DNA damage response (12). We sought to determine whether this pathway depends in part on activation of the ATM (ataxia telangiectasia mutated) kinase and whether the virus gains advantages from this pathway beyond that of entry into S. We show that polyomavirus infection activates the S- and G(2)-phase checkpoints in primary as well as established mouse cells. Infected cells undergo a prolonged S phase compared to uninfected serum-stimulated cells and show no evidence of a G(2)-> M transition before lytic death ensues. Infection is accompanied by increases in ATM activity in vitro and in the level of ATM-S1981-P in vivo. The incubation of infected cells with caffeine, a known ATM inhibitor, did not block entry into S but reduced the rate of viral compared to cellular DNA synthesis. Importantly, caffeine lowered the yields of viral DNA an average of 3- to 6-fold and those of infectious virus by as much as 10-fold. Virus yields were 10-fold lower in ATM(-/-) P53(-/-) than in ATM(+/+) P53(-/-) mouse embryo fibroblasts, indicating a p53-independent role of ATM in productive infection. Replacement of the normal SMC1 (structural maintenance of chromosomes, or cohesin) protein, a critical ATM substrate in the DNA repair pathway, with its phosphorylation mutant SMC1(S957AS966A) also lowered virus yields by roughly 90%. We suggest that polyomavirus activates and utilizes a component(s) of an ATM pathway of DNA repair to prolong S phase and aid its own replication.