Complementation of adenovirus virus-associated RNA I gene deletion by expression of a mutant eukaryotic translation initiation factor.
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 initiation. In this report we show growth complementation of adenoviruses harboring deletions in the VAI gene in cell 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.
Davies
M V
MV
Genetics Institute, Cambridge, MA 02140-2387.
Furtado
M
M
Hershey
J W
JW
Thimmappaya
B
B
Kaufman
R J
RJ
D000260:Adenoviruses, Human / Q000235:genetics*; D002460:Cell Line; D002872:Chromosome Deletion; D015852:Eukaryotic Initiation Factor-2 / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D005814:Genes, Viral; D005816:Genetic Complementation Test; D006801:Humans; D007700:Kinetics; D009154:Mutation; D010766:Phosphorylation; D010957:Plasmids; D011494:Protein Kinases / Q000378:metabolism*; D012367:RNA, Viral / Q000235:genetics*; D019892:eIF-2 Kinase
D015852:Eukaryotic Initiation Factor-2; D012367:RNA, Viral; C052835:adenovirus associated RNA; D011494:Protein Kinases; D019892:eIF-2 Kinase