Overlapping glycosylation sequon influences the glycosylation pattern of a chimeric protein expressed in tomato leaf and callus

Overlapping glycosylation sequon (OGS) is composed of two overlapping N-glycosylation sequons and has been found in certain glycoproteins with pharmaceutical value. With a growing interest to produce pharmaceutical glycoproteins in plants, it is important to establish the glycosylation pattern of OGS-containing proteins expressed in varying plant tissues. Here, a chimeric OGS (NNST)-containing gene and its mutated forms (NNAT and NASNAT) were expressed in callus-derived tomato plantlets. Tissue extracts from the recombinant leaf and callus were used in immunoblotting and glycoprotein detection. We found that the glycosylation patterns of the NNST-containing chimeric protein differ from that of NNAT- and NASNAT-containing proteins.

► OGS motif in recombinant proteins is accessible.
► Glycosylation pattern of an OGS-containing protein differs between tomato tissues.
► Presence or absence of an OGS motif in plant-expressed glycoproteins is important.