title: The S4 genome segment of baboon reovirus is bicistronic and encodes a novel fusion-associated small transmembrane protein.
abstract: We demonstrate that the S4 genome segment of baboon reovirus (BRV) contains two sequential partially overlapping open reading frames (ORFs), both of which are functional in vitro and in virus-infected cells. The 15-kDa gene product (p15) of the 5"-proximal ORF induces efficient cell-cell fusion when expressed by itself in transfected cells, suggesting that p15 is the only viral protein required for induction of syncytium formation by BRV. The p15 protein is a small, hydrophobic, basic, integral membrane protein, properties shared with the p10 fusion-associated small transmembrane (FAST) proteins encoded by avian reovirus and Nelson Bay reovirus. As with p10, the BRV p15 protein is also a nonstructural protein and, therefore, is not involved in virus entry. Sequence analysis indicates that p15 shares no significant sequence similarity with the p10 FAST proteins and contains a unique repertoire and arrangement of sequence-predicted structural and functional motifs. These motifs include a functional N-terminal myristylation consensus sequence, an N-proximal proline-rich motif, two potential transmembrane domains, and an intervening polybasic region. The unique structural properties of p15 suggest that this protein is a novel member of the new family of FAST proteins.
authors.affiliation: Department of Microbiology and Immunology, Tupper Medical Building, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada.
authors.forename: Sandra
authors.initials: S
authors.lastname: Dawe
authors.forename: Roy
authors.initials: R
authors.lastname: Duncan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002522:Chlorocebus aethiops; D016679:Genome, Viral; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D008992:Monkey Diseases / Q000821:virology; D016366:Open Reading Frames / Q000235:genetics; D018165:Orthoreovirus / Q000235:genetics* / Q000378:metabolism; D010215:Papio; D014176:Protein Biosynthesis; D012088:Reoviridae Infections / Q000662:veterinary / Q000821:virology; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic; D014162:Transfection; D014709:Vero Cells; D014760:Viral Fusion Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D014760:Viral Fusion Proteins