title: Piscine orthoreovirus (PRV) ơ3 protein binds dsRNA.
abstract: Piscine orthoreovirus (PRV) has a double-stranded, segmented RNA genome and belongs to the family Reoviridae. PRV is associated with heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar L.) and cause intraerythrocytic inclusions. The virus is widespread in both wild and farmed salmonid fish in Europe, North- and South America. In mammalian orthoreovirus (MRV), the outer capsid protein ơ3 has dsRNA binding properties, which serve to inhibit the early innate immune response of the host. Important structural motifs and key amino acid residues are conserved between MRV ơ3 and the homologous PRV protein, and we hypothesized that PRV ơ3 binds dsRNA. Gene regions and amino acid residues predicted to be important for dsRNA binding were determined through bioinformatic analysis and investigated functionally following site-directed mutagenesis and the generation of truncated ơ3 variants. Our results provide evidence that the PRV protein ơ3 binds dsRNA in a sequence independent manner, thus sharing this function with MRV ơ3. Although no specific domain solely responsible for dsRNA binding was determined, the results point to residues within a predominantly basic region to be important for this functional property. We conclude that multiple sites are involved in the dsRNA binding activity of PRV ơ3.
authors.affiliation: Department of Food Safety & Infection Biology, Norwegian University of Life Sciences, Oslo, Norway. Electronic address: oyfi@nmbu.no.
authors.forename: Øystein
authors.initials: Ø
authors.lastname: Wessel
authors.affiliation: Department of Food Safety & Infection Biology, Norwegian University of Life Sciences, Oslo, Norway. Electronic address: ingvild.nyman@nmbu.no.
authors.forename: Ingvild Berg
authors.initials: IB
authors.lastname: Nyman
authors.affiliation: Norwegian Veterinary Institute, Oslo, Norway. Electronic address: turhan.markussen@vetinst.no.
authors.forename: Turhan
authors.initials: T
authors.lastname: Markussen
authors.affiliation: Norwegian Veterinary Institute, Oslo, Norway. Electronic address: maria.dahle@vetinst.no.
authors.forename: Maria Krudtaa
authors.initials: MK
authors.lastname: Dahle
authors.affiliation: Department of Food Safety & Infection Biology, Norwegian University of Life Sciences, Oslo, Norway. Electronic address: espen.rimstad@nmbu.no.
authors.forename: Espen
authors.initials: E
authors.lastname: Rimstad
mesh_terms: D000818:Animals; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D019295:Computational Biology; D004252:DNA Mutational Analysis; D005399:Fishes; D016297:Mutagenesis, Site-Directed; D018165:Orthoreovirus / Q000235:genetics / Q000502:physiology*; D011485:Protein Binding; D012330:RNA, Double-Stranded / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D036022:Capsid Proteins; D012330:RNA, Double-Stranded; D016601:RNA-Binding Proteins
keywords: Atlantic salmon; Piscine orthoreovirus (PRV); dsRNA binding; ơ3 protein