Journal article
Modulation of Translation Initiation Efficiency in Classical Swine Fever Virus
Modulation of translation initiation efficiency on classical swine fever virus (CSFV) RNA can be achieved by targeted mutations within the internal ribosome entry site (IRES). In this study, cDNAs corresponding to the wild type (wt) or mutant forms of the IRES of CSFV strain Paderborn were amplified and inserted into dicistronic reporter plasmids encoding Fluc and Rluc under the control of a T7 promoter.
The mutations were within domains II, IIId1 and IIIf of the IRES. The plasmids were transfected into BHK cells infected with the recombinant vaccinia virus, vTF7-3, which expresses the T7 RNA polymerase. IRES mutants with different levels of IRES activity were identified and then introduced by homologous recombination into bacterial artificial chromosomes (BACs), containing CSFV Paderborn cDNA downstream of a T7 promoter.
From the wt and mutant BACs, full-length CSFV RNA transcripts were produced in vitro and electroporated into porcine PK15 cells. Rescued mutant viruses were obtained from RNAs that contained mutations within domain IIIf which retained more than 75% of wt translation efficiency. Sequencing of cDNA generated from these rescued viruses verified the maintenance of the introduced changes within the IRES.
The growth characteristics of each rescued mutant virus were compared to that of the wt virus. It was shown that viable mutant viruses with reduced translation initiation efficiency can be designed and generated and that viruses containing mutations within domain IIIf of the IRES have reduced growth in cell culture compared to the wt virus.
Language: | English |
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Publisher: | American Society for Microbiology |
Year: | 2012 |
Pages: | 8681-8692 |
ISSN: | 10985514 , 0022538x and 10706321 |
Types: | Journal article |
DOI: | 10.1128/JVI.00346-12 |
ORCIDs: | Rasmussen, Thomas Bruun and Belsham, Graham |
Animals Cell Line Classical Swine Fever Virus Cricetinae DNA, Complementary DNA, Viral Gene Expression Regulation, Viral Genes, Reporter Genetic Vectors Genome Replication and Regulation of Viral Gene Expression Mutation Peptide Chain Initiation, Translational Plasmids RNA, Viral Swine