title: The vaccinia virus A4OR gene product is a nonstructural, type II membrane glycoprotein that is expressed at the cell surface.
abstract: Gene A40R from vaccinia virus (VV) strain Western Reserve has been characterized. The open reading frame (ORF) was predicted to encode a 159 amino acid, 18152 Da protein with amino acid similarity to C-type animal lectins and to the VV A34R protein, a component of extracellular enveloped virus (EEV). Northern blotting and S1 nuclease mapping showed that gene A40R is transcribed early during infection from a position 12 nucleotides upstream of the ORF, producing a transcript of approximately 600 nucleotides. Rabbit anti-sera were raised against bacterial fusion proteins containing parts of the A40R protein. These were used to identify an 18 kDa primary translation product and N- and O-glycosylated forms of 28, 35 and 38 kDa. The A40R proteins were detected early during infection, formed higher molecular mass complexes under non-reducing conditions and were present on the cell surface but absent from virions. The proteins partitioned with integral membrane proteins in Triton X-114. Canine pancreatic microsomal membranes protected in vitro-translated A40R from proteinase K digestion, suggesting the A40R protein has type II membrane topology. A mutant virus with the A40R gene disrupted after amino acid 50, so as to remove the entire lectin-like domain, and a revertant virus were constructed. Disruption of the A40R gene did not affect virus plaque size, in vitro growth rate and titre, EEV formation, or virus virulence in a murine intranasal model.
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK1.
authors.forename: Diane
authors.initials: D
authors.lastname: Wilcock
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK1.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Duncan
authors.affiliation: Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA2.
authors.forename: Paula
authors.initials: P
authors.lastname: Traktman
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK1.
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Zhang
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK1.
authors.forename: Geoffrey L
authors.initials: GL
authors.lastname: Smith
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D002457:Cell Extracts; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism / Q000821:virology; D002522:Chlorocebus aethiops; D004285:Dogs; D005260:Female; D016679:Genome, Viral; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D017830:Octoxynol; D011092:Polyethylene Glycols; D014176:Protein Biosynthesis; D011817:Rabbits; D017421:Sequence Analysis; D014158:Transcription, Genetic; D014616:Vaccinia virus / Q000235:genetics / Q000378:metabolism*; D014709:Vero Cells; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism*; D014771:Virion
chemical_list: C121306:A40R protein, vaccinia virus; D002457:Cell Extracts; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D017361:Viral Nonstructural Proteins; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40