The role of proteolytic processing and the stable signal peptide in expression of the Old World arenavirus envelope glycoprotein ectodomain

► We investigated the biosynthesis of recombinant ectodomains of arenavirus glycoproteins (GPs). ► The arenavirus ectodomains underwent processing, followed by dissociation of GP1 from GP2. ► The GP2 ectodomain spontaneously formed post-fusion trimers. ► The SSP was dispensable for processing and secretion of the GP ectodomain.