title: Influence of NS5A protein of classical swine fever virus (CSFV) on CSFV internal ribosome entry site-dependent translation.
abstract: An internal ribosome entry site (IRES) present in the 5' untranslated region (UTR) promotes translation of classical swine fever virus (CSFV) genomes. Using an in vitro system with monocistronic reporter RNA containing the CSFV 5'UTR, this study found that CSFV NS5A decreased CSFV IRES-mediated translation in a dose-dependent manner. Deletion analysis showed that the region responsible for repressing CSFV IRES activity might cover aa 390-414, located in the C-terminal half of CSFV NS5A. Triple and single alanine-scanning mutagenesis revealed that the inhibitory effect on CSFV IRES-directed translation mapped to the K399, T401, E406 and L413 residues of NS5A. These important amino acids were also found to be present in the NS5A proteins of bovine viral diarrhea virus (BVDV)-1, BVDV-2, border disease virus and hepatitis C virus, indicating that NS5A may play an important role in the switch from translation to replication in these viruses.
authors.affiliation: College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China.
authors.forename: Ming
authors.initials: M
authors.lastname: Xiao
authors.affiliation: College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China.
authors.forename: Yujing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China.
authors.forename: Zailing
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China.
authors.forename: Jialin
authors.initials: J
authors.lastname: Yu
authors.affiliation: College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China.
authors.forename: Lingzhu
authors.initials: L
authors.lastname: Wan
authors.affiliation: College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D006692:Classical Swine Fever Virus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D008969:Molecular Sequence Data; D009154:Mutation; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000378:metabolism* / Q000821:virology; D013552:Swine; D014162:Transfection; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: C096041:NS5 protein, flavivirus; D017361:Viral Nonstructural Proteins