title: A sequence of basic residues in the porcine circovirus type 2 capsid protein is crucial for its co-expression and co-localization with the replication protein.
abstract: Porcine circovirus type 2 (PCV2) encodes two major proteins: the replication protein (Rep) and the capsid protein (Cap). Cap displays a conserved stretch of basic residues situated on the inside of the capsid, whose role is so far unknown. We used a reverse-genetics approach to investigate its function and found that mutations in these amino acids hindered Cap mRNA translation and hampered Cap/Rep co-localization, yielding unfit viruses. Intriguingly, co-transfection with a WT PCV2 of a different genotype partially rescued mutant Cap expression, showing the importance of this basic pattern for efficient translation of Cap mRNA into protein. Our results show that Cap and Rep are expressed independently of each other, and that this amino acid sequence of Cap is vital for virus propagation. This study provides a method for studying unfit PCV2 virions and offers new insights into the intracellular modus vivendi of PCV2.
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.|Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Maduan Street 427, Harbin 150001, PR China.
authors.forename: Liping
authors.initials: L
authors.lastname: Huang
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
authors.forename: Nicolaas
authors.initials: N
authors.lastname: Van Renne
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Maduan Street 427, Harbin 150001, PR China.
authors.forename: Changming
authors.initials: C
authors.lastname: Liu
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Nauwynck
mesh_terms: D000818:Animals; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D017925:Circovirus / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D005838:Genotype; D009154:Mutation; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D013552:Swine; D014779:Virus Replication / Q000502:physiology
chemical_list: D036022:Capsid Proteins; D004279:DNA, Viral; D012333:RNA, Messenger; D012367:RNA, Viral