title: Biosynthesis of the IFN-gamma binding protein of ectromelia virus, the causative agent of mousepox.
abstract: Ectromelia virus (ECTV), the causative agent of mousepox, expresses an extracellular interferon-gamma binding protein (IFN-gammaBP) with homology to the ligand binding domains of the IFN-gamma high affinity receptor (IFN-gammaR1). Unlike the cellular receptor, the IFN-gammaBP binds IFN-gamma from several species. The IFN-gammaBP is synthesized early after infection, accumulating in the extracellular milieu as dimers composed of two protein species with Mr of 34.6 or 33.0 kDa. Homodimers are covalently linked by an interchain disulphide bond at position 216. The IFN-gammaBP has complex N-linked oligosaccharides at positions 41 and 149 as determined by site-directed mutagenesis and glycosidase treatment. Glycosylation at position 41 is required for secretion from mammalian cells and may play a role in the activity of the IFN-gammaBP. Glycosylation at position 149 is not required for secretion, and the lack of glycosylation at this site does not diminish ligand binding as measured by surface plasmon resonance (SPR) and ELISA.
authors.affiliation: Department of Molecular Microbiology and Immunology, Saint Louis University Health Sciences Center, 1402 South Grand Boulevard, St. Louis, MO 63104, USA.
authors.forename: Hongdong
authors.initials: H
authors.lastname: Bai
authors.forename: R Mark L
authors.initials: RM
authors.lastname: Buller
authors.forename: Nanhai
authors.initials: N
authors.lastname: Chen
authors.forename: Michael
authors.initials: M
authors.lastname: Green
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Nuara
mesh_terms: D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D002460:Cell Line; D002522:Chlorocebus aethiops; D004279:DNA, Viral / Q000235:genetics; D004481:Ectromelia virus / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000472:pathogenicity; D004482:Ectromelia, Infectious / Q000209:etiology; D005814:Genes, Viral; D006031:Glycosylation; D007371:Interferon-gamma / Q000378:metabolism*; D051379:Mice; D016297:Mutagenesis, Site-Directed; D010957:Plasmids / Q000235:genetics; D014415:Tunicamycin / Q000494:pharmacology; D014764:Viral Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics
chemical_list: D002352:Carrier Proteins; D004279:DNA, Viral; D014764:Viral Proteins; D014415:Tunicamycin; D007371:Interferon-gamma