Summary
Evidence has suggested that the subgenomic RNA of the carlavirus potato virus S is an efficient message for the coat protein, even though evidence suggests it is uncapped at its 5′ terminus. We have investigated the effect of the upstream region of the coat protein gene of potato virus S on the level of reporter gene expression in vitro. The region of 101 nucleotides upstream of the coat protein, designated VTE (viral translational enhancer) was found to increase levels of translation in comparison to a synthetic leader when linked to the β-glucuronidase (GUS) reporter gene in vitro in rabbit reticulocyte and wheat germ lysate. VTE was also able to increase translation of the reporter gene luciferase (LUC) in vitro above the levels obtained for both a synthetic leader and a leader obtained from a plant gene isolated fromArabidopsis thaliana. The level of enhancement was evident with both capped and uncapped transcripts. When the VTE sequence was deleted to 20 nucleotides of the upstream region, thus removing the nucleotide block homologous among carlaviruses, the ability to enhance levels of translation was removed. In vitro translation studies indicated that the translational enhancement activity of VTE was at least partially cap independent. Translation of VTE linked to reporter genes in the presence of cap analogue was relatively unaffected whereas synthetic leader and a plant leader constructs were both more sensitive. In vitro competition analysis revealed that when short RNA transcripts representing the 101 nucleotides of VTE were added in trans to functional VTE leader LUC constructs there was a marked decrease in the level of translation when compared with a synthetic leader added in trans. These results suggest that the upstream region of the coat protein ORF of potato virus S promotes translation in a cap-independent manner that may involve the binding of proteins and/or ribosomes to the 101 nucleotides of the VTE sequence.
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References
Carrington JC, Freed DD (1990) Cap-independent enhancement of translation by a plant potyvirus 5′ nontranslated region. J Virol 64: 1590–1597
Foster GD (1991) Molecular variation between ordinary and Andean strains of potato virus S. Res Virol 142: 413–416
Foster GD (1992) The structure and expression of the genome of carlaviruses. Res Virol 143: 103–112
Foster GD, Mills PR (1990) Evidence for the role of subgenomic RNAs in the production of potato virus S coat protein during in vitro translation. J Gen Virol 71: 1247–1249
Foster GD, Mills PR (1990) Evidence for the role of subgenomic RNA species in the production of Helenium virus S coat protein during in vitro translation. Virus Res 17: 61–70
Foster GD, Mills PR (1990) Investigation of the 5′ terminal structures of genomic and subgenomic RNAs of potato virus S. Virus Genes 4: 359–366
Foster GD, Millar AW, Meehan BM, Mills PR (1990) Nucleotide sequence of the 3′-terminal region of Helenium virus S RNA. J Gen Virol 71: 1877–1880
Foster GD, Mills, PR (1991) Cell free translation of American hop latent virus. Virus Genes 5: 327–334
Foster GD, Mills PR (1991) Evidence for subgenomic RNAs in leaves infected with an Andean strain of potato virus S. Acta Virol 35: 260–267
Foster GD, Mills PR (1991) Occurrence of chloroplast ribosome binding recognition sites within conserved elements of the RNA genomes of carlaviruses. FEBS Lett 280: 341–343
Foster GD, Mills PR (1992) The 3′-nucleotide sequence of an ordinary strain of potato virus S. Virus Genes 6: 213–220
Furuichi Y, LaFiandra A, Shatkin AJ (1977) 5′-terminal structure and mRNA stability. Nature 266: 235–239
Kozak M (1983) Comparison of initiation of protein sysnthesis in prokaryotes, eukaryotes and organelles. Microbiol Rev 47: 1–45
Laemmli UK (1970) Clevage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227: 680–685
Meehan BM, Mills PR (1991) Cell-free translation of carnation latent virus RNA and analysis of virus specific dsRNA. Virus Genes 5: 175–181
Meehan BM, Mills PR (1991) Nucleotide sequence of the 3′-terminal region of carnation latent virus. Intervirology 32: 262–267
Memelink J, Van Der Vlugt CIM, Linthorst HJM, Derks AFLM, Asjes CJ, Bol JF (1990) Homologires between the genomes of a carlavirus (lily symptomless virus) and a potexvirus (lily virus X) from lily plants. J Gen Virol 71: 917–924
Morozov SYu, Kanyuka KV, Levay KE, Zavriev SK (1990) The putative RNA replicase of potato virus M: obvious sequence similarity with those of potex- and tymoviruses. Virology 179: 911–914
Pelletier J, Sonenberg N (1988) Internal iniation of translation of eukaryotic mRNA directed by a sequence derived from poliovirus RNA. Nature 334: 320–325
Rhoads RE (1988) Cap recognition and the entry of mRNA into the protein synthesis initiation cycle. Trends Biochem Sci 13: 52–56
Roberts MR, Foster GD, Blundell RP, Robinson SW, Kumar A, Draper J, Scott RJ (1993) An anther specific gene ofArabidopsis thaliana andBrassica napus is expressed in both gametophytic and sporophytic cell types during microspore development. Plant J 3: 111–121
Rupasov VV, Morozov SYu, Kanyuka KV, Zavriev SK (1989) Partial nucleotide sepuence of potato virus M RNA shows similarities to potexviruses in gene arrangement and the encoded amino acid sequences. J Gen Virol 70: 1861–1869
Sanger F, Nicklen S, Coulson AR (1977) DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci USA 74: 5463–5467
Travantzis SM (1991) Coat protein and protease activity as in vitro translation products of potato carlavirus M RNA. Arch Virol 120: 241–52
Zavriev SK, Kanyuka KV, Levay KE (1991) The genome organisation of potato virus M. J Gen Virol 72: 9–14
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Turner, R., Bate, N., Twell, D. et al. Analysis of a translational enhancer upstream from the coat protein open reading frame of potato virus S. Archives of Virology 134, 321–333 (1994). https://doi.org/10.1007/BF01310570
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DOI: https://doi.org/10.1007/BF01310570