title: Orsay virus utilizes ribosomal frameshifting to express a novel protein that is incorporated into virions.
abstract: Orsay virus is the first identified virus that is capable of naturally infecting Caenorhabditis elegans. Although it is most closely related to nodaviruses, Orsay virus differs from nodaviruses in its genome organization. In particular, the Orsay virus RNA2 segment encodes a putative novel protein of unknown function, termed delta, which is absent from all known nodaviruses. Here we present evidence that Orsay virus utilizes a ribosomal frameshifting strategy to express a novel fusion protein from the viral capsid (alpha) and delta ORFs. Moreover, the fusion protein was detected in purified virus fractions, demonstrating that it is most likely incorporated into Orsay virions. Furthermore, N-terminal sequencing of both the fusion protein and the capsid protein demonstrated that these proteins must be translated from a non-canonical initiation site. While the function of the alpha-delta fusion remains cryptic, these studies provide novel insights into the fundamental properties of this new clade of viruses.
authors: Departments of Molecular Microbiology and Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States.
authors: Hongbing
authors: H
authors: Jiang
authors: Departments of Molecular Microbiology and Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States.
authors: Carl J
authors: CJ
authors: Franz
authors: Departments of Molecular Microbiology and Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States.
authors: Guang
authors: G
authors: Wu
authors: Departments of Molecular Microbiology and Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States.
authors: Hilary
authors: H
authors: Renshaw
authors: Departments of Molecular Microbiology and Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States.
authors: Guoyan
authors: G
authors: Zhao
authors: Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom.
authors: Andrew E
authors: AE
authors: Firth
authors: Departments of Molecular Microbiology and Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States. Electronic address: davewang@borcim.wustl.edu.
authors: David
authors: D
authors: Wang
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D018965:Frameshifting, Ribosomal; D008969:Molecular Sequence Data; D030381:Nodaviridae / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis; D016415:Sequence Alignment; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014771:Virion / Q000235:genetics* / Q000378:metabolism
chemical_list: D036022:Capsid Proteins; D014764:Viral Proteins
keywords: Caenorhabditis elegans; Mass spectrometry; Orsay virus; Ribosomal frameshifting