The ATR Signaling Pathway Is Disabled during Infection with the Parvovirus Minute Virus of Mice
The ATR Signaling Pathway Is Disabled during Infection with the Parvovirus Minute Virus of Mice
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DOI：
10.1128/jvi.01412-14
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发表时间：
2014-09-01
影响因子：
5.4
通讯作者：
Pintel, David J.
中科院分区：
文献类型：
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作者：
Adeyemi, Richard O.;Pintel, David J.
ATR激酶在应对复制胁迫时维持基因组完整性方面具有重要功能。ATR通过其相互作用伙伴ATRIP被招募到DNA损伤位点的RPA包裹的单链DNA上，ATRIP与RPA的大亚基结合。ATR活化通常会导致Chk1激酶在其他底物中的活化。我们在这里表明，在小鼠单链细小病毒（MVM）复制过程中，ATR及其相关蛋白ATRIP与许多其他DNA修复蛋白一起被招募到病毒核复制室（自主细小病毒相关复制[APAR]体）。然而，Chk1在MVM感染期间没有被激活，即使携带结合RPA的病毒基因组在APAR体中积累，而RPA通常是ATR激活的有效触发器。在MVM感染时未能激活Chk1可能是由于我们观察到Rad9无法与MVM APAR小体的染色质结合。此外，在感染早期，在病毒诱导的DNA损伤反应（DDR）开始之前，羟基脲（HU）停止MVM基因组的复制，导致Chk1以病毒剂量依赖的方式磷酸化。然而，在病毒完全复制建立后，MVM感染阻止了Chk1对HU和各种其他药物治疗的激活。最后，在MVM感染后，无法检测到ATR磷酸化，尽管病毒感染诱导RPA32在丝氨酸33 （ATR相关的磷酸化位点）上磷酸化，但这种磷酸化事件不能通过ATR耗尽或抑制来阻止。总之，我们的研究结果表明，MVM感染使ATR信号通路失活。感染后，细小病毒MVM激活细胞DNA损伤反应，控制病毒诱导的细胞周期阻滞，这是有效的病毒复制所必需的。ATM和ATR是协调DNA损伤对不同DNA损伤刺激反应的主要细胞激酶。尽管在细小病毒感染期间已经发现了大量的ATM激活，但对ATR途径的参与研究较少。在MVM感染期间，即使携带结合细胞单链结合蛋白RPA（通常是ATR激活的有效触发因子）的病毒基因组在病毒复制中心积累，ATR的主要下游靶点Chk1也没有被检测到磷酸化。ATR磷酸化也无法检测到。此外，在病毒完全复制建立后，MVM感染阻止了Chk1对羟基脲和各种其他药物治疗的激活。我们的研究结果表明，MVM感染使这一重要的细胞信号通路失效。
The ATR kinase has essential functions in maintenance of genome integrity in response to replication stress. ATR is recruited to RPA-coated single-stranded DNA at DNA damage sites via its interacting partner, ATRIP, which binds to the large subunit of RPA. ATR activation typically leads to activation of the Chk1 kinase among other substrates. We show here that, together with a number of other DNA repair proteins, both ATR and its associated protein, ATRIP, were recruited to viral nuclear replication compartments (autonomous parvovirus-associated replication [APAR] bodies) during replication of the single-stranded parvovirus minute virus of mice (MVM). Chk1, however, was not activated during MVM infection even though viral genomes bearing bound RPA, normally a potent trigger of ATR activation, accumulate in APAR bodies. Failure to activate Chk1 in response to MVM infection was likely due to our observation that Rad9 failed to associate with chromatin at MVM APAR bodies. Additionally, early in infection, prior to the onset of the virus-induced DNA damage response (DDR), stalling of the replication of MVM genomes with hydroxyurea (HU) resulted in Chk1 phosphorylation in a virus dose-dependent manner. However, upon establishment of full viral replication, MVM infection prevented activation of Chk1 in response to HU and various other drug treatments. Finally, ATR phosphorylation became undetectable upon MVM infection, and although virus infection induced RPA32 phosphorylation on serine 33, an ATR-associated phosphorylation site, this phosphorylation event could not be prevented by ATR depletion or inhibition. Together our results suggest that MVM infection disables the ATR signaling pathway.IMPORTANCEUpon infection, the parvovirus MVM activates a cellular DNA damage response that governs virus-induced cell cycle arrest and is required for efficient virus replication. ATM and ATR are major cellular kinases that coordinate the DNA damage response to diverse DNA damage stimuli. Although a significant amount has been discovered about ATM activation during parvovirus infection, involvement of the ATR pathway has been less studied. During MVM infection, Chk1, a major downstream target of ATR, is not detectably phosphorylated even though viral genomes bearing the bound cellular single-strand binding protein RPA, normally a potent trigger of ATR activation, accumulate in viral replication centers. ATR phosphorylation also became undetectable. In addition, upon establishment of full viral replication, MVM infection prevented activation of Chk1 in response to hydroxyurea and various other drug treatments. Our results suggest that MVM infection disables this important cellular signaling pathway.