title: The role of proteolytic processing and the stable signal peptide in expression of the Old World arenavirus envelope glycoprotein ectodomain.
abstract: Maturation of the arenavirus GP precursor (GPC) involves proteolytic processing by cellular signal peptidase and the proprotein convertase subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P), yielding a tripartite complex comprised of a stable signal peptide (SSP), the receptor-binding GP1, and the fusion-active transmembrane GP2. Here we investigated the roles of SKI-1/S1P processing and SSP in the biosynthesis of the recombinant GP ectodomains of lymphocytic choriomeningitis virus (LCMV) and Lassa virus (LASV). When expressed in mammalian cells, the LCMV and LASV GP ectodomains underwent processing by SKI-1/S1P, followed by dissociation of GP1 from GP2. The GP2 ectodomain spontaneously formed trimers as revealed by chemical cross-linking. The endogenous SSP, known to be crucial for maturation and transport of full-length arenavirus GPC was dispensable for processing and secretion of the soluble GP ectodomain, suggesting a specific role of SSP in the stable prefusion conformation and transport of full-length GPC.
authors.affiliation: Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011, Switzerland.
authors.forename: Dominique J
authors.initials: DJ
authors.lastname: Burri
authors.forename: Antonella
authors.initials: A
authors.lastname: Pasquato
authors.forename: Joel Ramos
authors.initials: JR
authors.lastname: da Palma
authors.forename: Sebastien
authors.initials: S
authors.lastname: Igonet
authors.forename: Michael B A
authors.initials: MB
authors.lastname: Oldstone
authors.forename: Stefan
authors.initials: S
authors.lastname: Kunz
mesh_terms: D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D006023:Glycoproteins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D007836:Lassa virus / Q000378:metabolism*; D008217:Lymphocytic choriomeningitis virus / Q000378:metabolism*; D043484:Proprotein Convertases / Q000378:metabolism*; D021382:Protein Sorting Signals; D059748:Proteolysis; D012697:Serine Endopeptidases / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; D021382:Protein Sorting Signals; D014759:Viral Envelope Proteins; D043484:Proprotein Convertases; D012697:Serine Endopeptidases; C115575:membrane-bound transcription factor peptidase, site 1