title: Recombinant bovine respiratory syncytial virus with deletions of the G or SH genes: G and F proteins bind heparin.
abstract: Bovine respiratory syncytial virus (BRSV) encodes three transmembrane envelope glycoproteins, namely the small hydrophobic (SH) protein, the attachment glycoprotein (G) and the fusion glycoprotein (F). The BRSV reverse genetics system has been used to generate viable recombinant BRSV lacking either the G gene or the SH gene or both genes. The deletion mutants were fully competent for multicycle growth in cell culture, proving that, of the BRSV glycoprotein genes, the SH and G genes are non-essential. Virus morphogenesis was not impaired by either of the deletions. The deletion mutants were used to study the role of the F glycoprotein and the contributions of SH and G with respect to virus attachment. Attachment mediated by the F protein alone could be blocked by soluble heparin, but not by chondroitin sulphate. Heparin affinity chromatography revealed that both the BRSV G and F glycoproteins have heparin-binding activity, with the affinity of the F glycoprotein being significantly lower than that of G. Therefore, the roles of the BRSV glycoproteins in virus attachment and receptor binding have to be reconsidered.
authors.affiliation: Institute of Molecular Biology, Friedrich-Loeffler-Institutes, Federal Research Centre for Virus Diseases of Animals, Boddenblick 5a, D-17498 Insel Riems, Germany1.
authors.forename: Axel
authors.initials: A
authors.lastname: Karger
authors.affiliation: Institute of Molecular Biology, Friedrich-Loeffler-Institutes, Federal Research Centre for Virus Diseases of Animals, Boddenblick 5a, D-17498 Insel Riems, Germany1.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Schmidt
authors.affiliation: Institute of Molecular Biology, Friedrich-Loeffler-Institutes, Federal Research Centre for Virus Diseases of Animals, Boddenblick 5a, D-17498 Insel Riems, Germany1.
authors.forename: Ursula J
authors.initials: UJ
authors.lastname: Buchholz
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D002417:Cattle; D018929:Cell Culture Techniques; D002460:Cell Line; D006224:Cricetinae; D017353:Gene Deletion; D015870:Gene Expression; D006493:Heparin / Q000378:metabolism*; D016296:Mutagenesis; D009500:Neutralization Tests; D011817:Rabbits; D011995:Recombination, Genetic; D018112:Respiratory Syncytial Virus, Bovine / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D014158:Transcription, Genetic; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D014760:Viral Fusion Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
chemical_list: D000914:Antibodies, Viral; C066028:G protein, Bovine respiratory syncytial virus; D014759:Viral Envelope Proteins; D014760:Viral Fusion Proteins; D014764:Viral Proteins; D006493:Heparin