Department of Microbiology, Pearson Hall, Miami University, 700 E. High Street, Oxford, OH 45056, United States.
Department of Microbiology, Pearson Hall, Miami University, 700 E. High Street, Oxford, OH 45056, United States; Cell Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, United States.
Virology. 2019 Jan 15;527:47-56. doi: 10.1016/j.virol.2018.11.003. Epub 2018 Nov 16.
Adenovirus (Ad) type 5 (Ad5) E4 deletion mutants including H5dl1007 (E4-) induce a DNA damage response (DDR) that activates the kinase ataxia-telangiectasia mutated (ATM), which can interfere with efficient viral DNA replication. We find that localization of active phosphorylated ATM (pATM) to E4- viral replication centers (VRCs) is important for its inhibitory effect. ATM is necessary for localization of RNF8 and 53BP1 to E4 mutant VRCs, while recruitment of DDR factors Mre11, Mdc1 and γH2AX is ATM-independent, raising the possibility that ATM may affect viral chromatin at VRCs. We assessed E4- and Ad5 chromatin organization by micrococcal nuclease (MN) digestion. A significant fraction of Ad5 DNA is somewhat resistant to MN digestion, whereas E4- DNA is more susceptible. ATM inhibition increases the fraction of E4- DNA that is resistant to MN digestion. Our results address possible mechanisms through which ATM inhibits E4- DNA replication.
腺病毒（Ad）5 型（Ad5）E4 缺失突变体包括 H5dl1007（E4-），可诱导 DNA 损伤反应（DDR），激活共济失调毛细血管扩张突变（ATM）激酶，从而干扰有效的病毒 DNA 复制。我们发现，活性磷酸化 ATM（pATM）定位于 E4-病毒复制中心（VRC）对于其抑制作用很重要。ATM 对于 RNF8 和 53BP1 定位于 E4 突变 VRC 是必需的，而 DDR 因子 Mre11、Mdc1 和 γH2AX 的募集则不依赖于 ATM，这表明 ATM 可能影响 VRC 处的病毒染色质。我们通过微球菌核酸酶（MN）消化评估了 E4-和 Ad5 染色质组织。Ad5 DNA 的相当一部分对 MN 消化具有一定的抗性，而 E4-DNA 则更敏感。ATM 抑制增加了对 MN 消化具有抗性的 E4-DNA 部分。我们的结果解决了 ATM 如何抑制 E4-DNA 复制的可能机制。
