Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
J Virol. 2014 Feb;88(3):1473-83. doi: 10.1128/JVI.02321-13. Epub 2013 Nov 6.
The host eIF4F translation initiation complex plays a critical role the translation of capped mRNAs. Although human cytomegalovirus (HCMV) infection increases the abundance and activity of the host eIF4F complex, the requirement for eIF4F components in HCMV replication and mRNA translation has not been directly tested. In this study, we found that decreasing the abundance or activity of eIF4F from the start of infection inhibits HCMV replication. However, as infection progresses, viral mRNA translation and replication becomes increasingly resistant to eIF4F inhibition. During the late stage of infection the association of representative immediate-early, early, and late mRNAs with polysomes was not affected by eIF4F disruption. In contrast, eIF4F inhibition decreased the translation of representative host eIF4F-dependent mRNAs during the late stage of infection. A global analysis of the translation efficiency of HCMV mRNAs during the late stage of infection found that eIF4F disruption had a minimal impact on the association of HCMV mRNAs with polysomes but significantly diminished the translation efficiency of eIF4F-dependent host transcripts. Together, our data show that the translation of host eIF4F-dependent mRNAs remains dependent on eIF4F activity during HCMV infection. However, during the late stage of infection the translation efficiency of viral mRNAs does not correlate with the abundance or activity of the host eIF4F complex.
宿主 eIF4F 翻译起始复合物在翻译 capped mRNA 中起着关键作用。尽管人类巨细胞病毒(HCMV)感染会增加宿主 eIF4F 复合物的丰度和活性,但 eIF4F 成分在 HCMV 复制和 mRNA 翻译中的作用尚未直接测试。在这项研究中,我们发现从感染开始时降低 eIF4F 的丰度或活性会抑制 HCMV 复制。然而,随着感染的进展,病毒 mRNA 的翻译和复制对 eIF4F 抑制的抵抗力越来越强。在感染的晚期,代表性的即刻早期、早期和晚期 mRNA 与多核糖体的结合不受 eIF4F 破坏的影响。相比之下,eIF4F 抑制会降低感染晚期代表性宿主 eIF4F 依赖性 mRNA 的翻译。对 HCMV 晚期感染时 mRNA 翻译效率的全面分析发现,eIF4F 破坏对 HCMV mRNA 与多核糖体的结合几乎没有影响,但显著降低了宿主转录物的翻译效率。总之,我们的数据表明,在 HCMV 感染期间,宿主 eIF4F 依赖性 mRNA 的翻译仍然依赖于 eIF4F 活性。然而,在感染的晚期,病毒 mRNA 的翻译效率与宿主 eIF4F 复合物的丰度或活性无关。