Abstract
Baculovirus expression systems (BES) are widely used for recombinant protein production in lepidopteran cells or larvae. It is known that insect cells have a glycosylation pathway similar to that of mammalian cells. Thus, BES are possible to be used to produce recombinant proteins with higher eukaryotic modifications. In insect cells, the N-glycosylation pathway has been well-researched. However, the O-glycosylation pathway is poorly understood. In this study, we expressed a partial recombinant HsPRG4 (rPRG4) as a reporter for O-glycosylation and investigated whether BES in silkworm could produce the proteins with mucin-like clustered O-glycans. Analysis by SDS-PAGE and glycosidase digestion indicated that rPRG4 had Core 1 and Core 2 O-glycan chains. These results suggested that BES could produce the protein containing mucin-type O-glycosylation in Bombyx mori.