5' SEQUENCE OF VESICULAR STOMATITIS-VIRUS N-GENE CONFERS SELECTIVE TRANSLATION OF MESSENGER-RNA

The infection of cells by vesicular stomatitis virus results in the rapid inhibition of host-cell protein synthesis, but not of viral protein synthesis. To determine if this translational selectivity might be conferred by the viral mRNA, we constructed a plasmid (pUCLNβ-4) containing the 5′ end of the viral nucleocapsid (N)-gene, including the ribosome binding site, fused in frame with the gene encoding β-galactosidase, and compared it to a control plasmid (pMC1924) containing the cellular rabbit beta-globin gene 5′ end fused with the β-galactosidase encoding gene. Both plasmids contained identical promoter and 3′ nontranslated regions and expressed similar levels of β-galactosidase in the indicator cell line 293. In cells transfected with either plasmid, viral infection resulted in a ∼70% decrease in protein synthesis by five hours. The level of β-galactosidase from cells transfected with pMC1924 also decreased concomitantly with the decrease in total protein synthesis. However, the level of β-galactosidase from cells transfected with pUCLNβ-4 was not affected by viral infection. Our data suggest that sequences in the 5′ end of the viral mRNA allow for the selective translation of the viral message in the presence of an inhibited translational machinery. © 1992.