N-linked oligosaccharide processing is not necessary for glycoprotein secretion in plants

✍ Scribed by Patrice Lerouge; Anne-Catherine Fitchette-Lainé; Aïcha Chekkafi; Véronique Avidgor; Loïc Faye

• Book ID: 104463609
• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 820 KB
• Volume: 10
• Category: Article
• ISSN: 0960-7412
• DOI: 10.1046/j.1365-313x.1996.10040713.x

✦ Synopsis

The role of N‐glycans in the secretion of glycoproteins by suspension‐cultured sycamore cells was studied. The transport of glycoproteins to the extracellular compartment was investigated in the presence of a glycan‐processing inhibitor, castanospermine. Castanospermine has been selected because it inhibits homogeneously glycan maturation in sycamore cells and leads to the accumulation of a single immature N‐glycan. The structure of this glycan has been identified as Glc~3~Man~7~GlcNAc~2~ by labeling experiments, affinity chromatography on concanavalin A‐Sepharose and proton NMR. In contrast with previous results showing that N‐glycosylation is a pre‐requisite for secretion of N‐linked glycoproteins, this secretion is not affected by the presence of castanospermine. As a consequence, the presence of this unprocessed glycan is sufficient for an efficient secretion of glycoproteins in the extracellular compartment of suspension‐cultured sycamore cells.