COMPLEMENTATION OF ADENOVIRUS VIRUS-ASSOCIATED RNA-I GENE DELETION BY EXPRESSION OF A MUTANT EUKARYOTIC TRANSLATION INITIATION-FACTOR
COMPLEMENTATION OF ADENOVIRUS VIRUS-ASSOCIATED RNA-I GENE DELETION BY EXPRESSION OF A MUTANT EUKARYOTIC TRANSLATION INITIATION-FACTOR
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DOI：
10.1073/pnas.86.23.9163
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发表时间：
1989-12-01
影响因子：
11.1
通讯作者：
KAUFMAN, RJ
中科院分区：
文献类型：
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作者：
DAVIES, MV;FURTADO, M;KAUFMAN, RJ
腺病毒VA RNA（病毒相关RNA）是由聚合酶III转录的小分子RNA，在腺病毒感染后期高效起始mRNA翻译过程中是必需的。VAI RNA可阻止干扰素诱导的蛋白激酶（DAI激酶）被双链RNA（dsRNA）激活。该激酶的激活会导致真核翻译起始因子2的α亚基（eIF - 2α）磷酸化，并与翻译抑制相关。在本研究报告中，我们展示了在表达eIF - 2α的丝氨酸突变为丙氨酸突变体的细胞系中，VAI基因缺失的腺病毒的生长互补情况。这种丝氨酸到丙氨酸的突变体对DAI激酶的磷酸化具有抗性。这些结果直接表明，在裂解性腺病毒感染中VAI RNA的主要功能是抑制DAI激酶对eIF - 2α的磷酸化，并确定eIF - 2α是介导DAI激酶激活效应的靶点。表达突变型eIF - 2α的细胞将能够分离出其他类型病毒的特定宿主范围突变体，这些病毒在抑制DAI激酶的能力方面存在缺陷。
Adenovirus VA RNAs (virus-associated RNAs) are small polymerase III transcripts that are required for efficient initiation of mRNA translation late in adenovirus infection. VAI RNA prevents double-stranded RNA (dsRNA) activation of the interferon-induced protein kinase (DAI kinase). Activation of this kinase results in phosphorylation of the .alpha. subunit of eukaryotic translation initiation factor 2 (eIF-2.alpha.) and correlates with inhibition of translation. In this report we show growth complementation of adenoviruses harboring deletions in the VAI gene in cells lines expressing a serine-to-alanine mutant of eIF-2.alpha.. This serine-to-alanine mutant is resistant to phosphorylation by DAI kinase. These results directly show that the primary function of VAI RNA in the lytic adenovirus infection is the inhibition of eIF-2.alpha. phosphorylation by DAI kinase and identify eIF-2.alpha. as the target that mediates the effects of DAI kinase activation. Cells that express a mutant eIF-2.alpha. will enable the isolation of specific host-range mutants for other types of viruses that are defective in the ability to inhibit DAI kinase.