Targeting of a multicomponent transcription apparatus into assembling vaccinia virus particles requires RAP94, an RNA polymerase-associated protein.
When expression of the vaccinia virus gene encoding RAP94 (a protein that is associated with the viral multisubunit RNA polymerase and confers transcriptional specificity for early promoters) was repressed, the infectious virus yield was reduced by more than 99%. Nevertheless, intermediate- and late-stage viral gene expression and formation of ultrastructurally mature, membrane-enveloped virions occurred under the nonpermissive conditions. The RAP94-deficient particles contained the viral genome, structural proteins, early transcription factor, and certain enzymes but, unlike normal virions, had low or undetectable amounts of the viral RNA polymerase, capping enzyme/termination factor, poly(A) polymerase, DNA-dependent ATPase, RNA helicase, and topoisomerase. The presence of these viral enzymes in the cytoplasm indicated that RAP94 is required for targeting a complex of functionally related proteins involved in the biosynthesis of mRNA.
Zhang
Y
Y
Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
Ahn
B Y
BY
Moss
B
B
D001483:Base Sequence; D003593:Cytoplasm / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases; D006367:HeLa Cells; D006801:Humans; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics; D014158:Transcription, Genetic; D014616:Vaccinia virus / Q000254:growth & development* / Q000472:pathogenicity / Q000648:ultrastructure; D014764:Viral Proteins / Q000096:biosynthesis; D014771:Virion / Q000254:growth & development / Q000648:ultrastructure
C085819:RAP94 protein, Vaccinia virus; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases