Inhibition of the Ubiquitin-Proteasome System Prevents Vaccinia Virus DNA Replication and Expression of Intermediate and Late Genes
Inhibition of the Ubiquitin-Proteasome System Prevents Vaccinia Virus DNA Replication and Expression of Intermediate and Late Genes
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DOI：
10.1128/jvi.01986-08
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发表时间：
2009-03-15
影响因子：
5.4
通讯作者：
Moss, Bernard
中科院分区：
文献类型：
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作者：
Satheshkumar, P. S.;Anton, Luis C.;Moss, Bernard
泛素-蛋白酶体系统在细胞内蛋白质的降解中起着重要作用，并调节多种功能。属于几个不同家族的病毒利用或调节该系统以获得其优势。在这里，我们发现蛋白酶体抑制剂MG 132和环氧霉素阻断了牛痘病毒（VACV）复制中的一个后期步骤。当病毒附着后加入蛋白酶体抑制剂时，早期基因表达延长，中期和晚期基因的表达几乎检测不到。通过改变去除和添加MG 132的时间，蛋白酶体抑制剂的不良反应仅集中在感染后2至4小时（病毒DNA合成开始的时间）发生的事件。进一步的分析证实，基因组复制被MG 132和环氧霉素抑制，这将解释对中期和晚期基因表达的影响。转染质粒的病毒诱导的复制也被抑制，表明阻断不在病毒DNA脱壳的步骤。UBEI-41，一种泛素激活酶E1的抑制剂，也阻止了晚期基因表达，支持了泛素-蛋白酶体系统在VACV复制中的作用。无论是泛素的过表达还是添加自噬抑制剂都不能对抗MG 132的抑制作用。进一步研究泛素-蛋白酶体系统在VACV复制中的作用可能为病毒-宿主相互作用提供新的见解，并提出潜在的抗痘病毒药物。
The ubiquitin-proteasome system has a central role in the degradation of intracellular proteins and regulates a variety of functions. Viruses belonging to several different families utilize or modulate the system for their advantage. Here we showed that the proteasome inhibitors MG132 and epoxomicin blocked a postentry step in vaccinia virus (VACV) replication. When proteasome inhibitors were added after virus attachment, early gene expression was prolonged and the expression of intermediate and late genes was almost undetectable. By varying the time of the removal and addition of MG132, the adverse effect of the proteasome inhibitors was narrowly focused on events occurring 2 to 4 h after infection, the time of the onset of viral DNA synthesis. Further analyses confirmed that genome replication was inhibited by both MG132 and epoxomicin, which would account for the effect on intermediate and late gene expression. The virus-induced replication of a transfected plasmid was also inhibited, indicating that the block was not at the step of viral DNA uncoating. UBEI-41, an inhibitor of the ubiquitin-activating enzyme E1, also prevented late gene expression, supporting the role of the ubiquitin-proteasome system in VACV replication. Neither the overexpression of ubiquitin nor the addition of an autophagy inhibitor was able to counter the inhibitory effects of MG132. Further studies of the role of the ubiquitin-proteasome system for VACV replication may provide new insights into virus-host interactions and suggest potential antipoxviral drugs.