title: Oxidative stress influences positive strand RNA virus genome synthesis and capping.
abstract: Flaviviruses are 5' capped positive-stranded RNA viruses that replicate their genomes within endoplasmic reticulum-derived vesicles. Flaviviruses are well known to induce oxidative stress late in infection but it is unknown if oxidative stress plays a positive role in the viral RNA replication cycle. We therefore examined how oxidation affects flavivirus RNA replication. We found that antioxidant treatment reduced virus production, reduced the viral positive-to-negative strand RNA ratio, and resulted in the accumulation of uncapped positive-sense viral RNAs. Treatment of the NS5 RNA capping enzyme in vitro with oxidizing agents enhanced guanylyltransferase activity, indicating that the guanylyltransferase function of the flavivirus NS5 RNA capping enzyme is activated by oxidative conditions. Antioxidant treatment also reduced alphavirus RNA replication and protein expression while enhancing nsP1 capping activity. These findings suggest that RNA viruses may utilize oxidative stress induced during infection to help temporally control genome RNA capping and genome replication.
authors.affiliation: Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA.
authors.forename: Rebekah C
authors.initials: RC
authors.lastname: Gullberg
authors.affiliation: Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA.
authors.forename: J
authors.initials: J
authors.lastname: Jordan Steel
authors.affiliation: Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA.
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Moon
authors.affiliation: Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA.
authors.forename: Elnaz
authors.initials: E
authors.lastname: Soltani
authors.affiliation: Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA; Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA. Electronic address: Brian.Geiss@colostate.edu.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Geiss
mesh_terms: D000330:Aedes; D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D016679:Genome, Viral / Q000502:physiology*; D006801:Humans; D009713:Nucleotidyltransferases / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D012315:RNA Caps / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012845:Sindbis Virus / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D014902:West Nile virus / Q000235:genetics*
chemical_list: D012315:RNA Caps; D011994:Recombinant Proteins; D014764:Viral Proteins; D009713:Nucleotidyltransferases; C020842:guanylyltransferase
keywords: Flavivirus; Guanylyltransferase; Oxidation; RNA capping