Back to Search
Start Over
Genetic manipulation of a transcription-regulating sequence of porcine reproductive and respiratory syndrome virus reveals key nucleotides determining its activity.
- Source :
- Archives of Virology; Aug2014, Vol. 159 Issue 8, p1927-1940, 14p
- Publication Year :
- 2014
-
Abstract
- The factors that determine the transcription-regulating sequence (TRS) activity of porcine reproductive and respiratory syndrome virus (PRRSV) remain largely unclear. In this study, the effect of mutagenesis of conserved C nucleotides at positions 5 and 6 in the leader TRS (TRS-L) and/or canonical body TRS7 (TRS-B) on the synthesis of subgenomic (sg) mRNA and virus infectivity was investigated in the context of a type 2 PRRSV infectious cDNA clone. The results showed that a double C mutation in the leader TRS completely abolished sg mRNAs synthesis and virus infectivity, but a single C mutation did not. A single C or double C mutation in TRS-B or/and TRS-B impaired or abolished the corresponding sg mRNA synthesis. Introduction of identical mutations in the leader and body TRSs partially restored sg mRNA7.1 and/or sg mRNA7.2 transcription, indicating that the base-pairing interaction between sense TRS-L and cTRS-B is a crucial factor influencing sg mRNA synthesis. Analysis of the mRNA leader-body junctions of mutants provided evidence for a mechanism of discontinuous minus-strand transcription. This study also showed that mutational inactivation of TRS-B or TRS-B did not affect the production of infectious progeny virus, and the sg mRNA formed from each of them could express N protein. However, TRS-B plays more important roles than TRS-B in maintaining the growth characteristic of type 2 PRRSV. These results provide more insight into the molecular mechanism of genome expression and subgenomic mRNA transcription of PRRSV. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03048608
- Volume :
- 159
- Issue :
- 8
- Database :
- Complementary Index
- Journal :
- Archives of Virology
- Publication Type :
- Academic Journal
- Accession number :
- 97252880
- Full Text :
- https://doi.org/10.1007/s00705-014-2018-2