title: Turnover Rate of NS3 Proteins Modulates Bluetongue Virus Replication Kinetics in a Host-Specific Manner.
abstract: Bluetongue virus (BTV) is an arbovirus transmitted to livestock by midges of the Culicoides family and is the etiological agent of a hemorrhagic disease in sheep and other ruminants. In mammalian cells, BTV particles are released primarily by virus-induced cell lysis, while in insect cells they bud from the plasma membrane and establish a persistent infection. BTV possesses a ten-segmented double-stranded RNA genome, and NS3 proteins are encoded by segment 10 (Seg-10). The viral nonstructural protein 3 (NS3) plays a key role in mediating BTV egress as well as in impeding the in vitro synthesis of type I interferon in mammalian cells. In this study, we asked whether genetically distant NS3 proteins can alter BTV-host interactions. Using a reverse genetics approach, we showed that, depending on the NS3 considered, BTV replication kinetics varied in mammals but not in insects. In particular, one of the NS3 proteins analyzed harbored a proline at position 24 that leads to its rapid intracellular decay in ovine but not in Culicoides cells and to the attenuation of BTV virulence in a mouse model of disease. Overall, our data reveal that the genetic variability of Seg-10/NS3 differentially modulates BTV replication kinetics in a host-specific manner and highlight the role of the host-specific variation in NS3 protein turnover rate.
  
  
  OBJECTIVE
  BTV is the causative agent of a severe disease transmitted between ruminants by biting midges of Culicoides species. NS3, encoded by Seg-10 of the BTV genome, fulfills key roles in BTV infection. As Seg-10 sequences from various BTV strains display genetic variability, we assessed the impact of different Seg-10 and NS3 proteins on BTV infection and host interactions. In this study, we revealed that various Seg-10/NS3 proteins alter BTV replication kinetics in mammals but not in insects. Notably, we found that NS3 protein turnover may vary in ovine but not in Culicoides cells due to a single amino acid residue that, most likely, leads to rapid and host-dependent protein degradation. Overall, this study highlights that genetically distant BTV Seg-10/NS3 influence BTV biological properties in a host-specific manner and increases our understanding of how NS3 proteins contribute to the outcome of BTV infection.
authors.affiliation: UMR754, Université Claude Bernard Lyon 1, Institut National de la Recherche Agronomique, Ecole Pratique des Hautes Etudes, SFR BioSciences Gerland, Lyon, France.
authors.forename: Najate
authors.initials: N
authors.lastname: Ftaich
authors.affiliation: UMR754, Université Claude Bernard Lyon 1, Institut National de la Recherche Agronomique, Ecole Pratique des Hautes Etudes, SFR BioSciences Gerland, Lyon, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Ciancia
authors.affiliation: UMR1161 Virology, Université Paris-Est, Laboratory for Animal Health, Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail, Institut National de la Recherche Agronomique, Ecole Nationale Vétérinaire d'Alfort, LabEx IBEID, Maisons-Alfort, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Viarouge
authors.affiliation: MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom.
authors.forename: Gerald
authors.initials: G
authors.lastname: Barry
authors.affiliation: MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom.
authors.forename: Maxime
authors.initials: M
authors.lastname: Ratinier
authors.affiliation: Department of Virology, Central Veterinary Institute of Wageningen UR (CVI), Wageningen, The Netherlands Department of Biochemistry, Centre for Human Metabonomics, North-West University, South Africa.
authors.forename: Piet A
authors.initials: PA
authors.lastname: van Rijn
authors.affiliation: UMR1161 Virology, Université Paris-Est, Laboratory for Animal Health, Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail, Institut National de la Recherche Agronomique, Ecole Nationale Vétérinaire d'Alfort, LabEx IBEID, Maisons-Alfort, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Breard
authors.affiliation: UMR1161 Virology, Université Paris-Est, Laboratory for Animal Health, Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail, Institut National de la Recherche Agronomique, Ecole Nationale Vétérinaire d'Alfort, LabEx IBEID, Maisons-Alfort, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Vitour
authors.affiliation: UMR1161 Virology, Université Paris-Est, Laboratory for Animal Health, Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail, Institut National de la Recherche Agronomique, Ecole Nationale Vétérinaire d'Alfort, LabEx IBEID, Maisons-Alfort, France.
authors.forename: Stephan
authors.initials: S
authors.lastname: Zientara
authors.affiliation: MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom.
authors.forename: Massimo
authors.initials: M
authors.lastname: Palmarini
authors.affiliation: UMR754, Université Claude Bernard Lyon 1, Institut National de la Recherche Agronomique, Ecole Pratique des Hautes Etudes, SFR BioSciences Gerland, Lyon, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Terzian
authors.affiliation: UMR754, Université Claude Bernard Lyon 1, Institut National de la Recherche Agronomique, Ecole Pratique des Hautes Etudes, SFR BioSciences Gerland, Lyon, France frederick.arnaud@univ-lyon1.fr.
authors.forename: Frédérick
authors.initials: F
authors.lastname: Arnaud
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000378:metabolism / Q000473:pathology / Q000821:virology; D001820:Bluetongue virus / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002461:Cell Line, Transformed; D002519:Ceratopogonidae; D002831:Choroid Plexus / Q000378:metabolism / Q000473:pathology / Q000821:virology; D003412:Cricetulus; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology / Q000821:virology*; D015967:Gene Expression Regulation, Viral; D016679:Genome, Viral; D058507:Host Specificity; D051379:Mice; D008969:Molecular Sequence Data; D061251:Primary Cell Culture; D055550:Protein Stability; D059748:Proteolysis; D059386:Reverse Genetics; D012756:Sheep; D015398:Signal Transduction; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D057074:Virus Release / Q000235:genetics; D014779:Virus Replication / Q000235:genetics*
chemical_list: C075080:S10 protein, Bluetongue virus; D017361:Viral Nonstructural Proteins