Structure, biosynthesis, and function of asparagine-linked glycans on plant glycoproteins

In plants, glycoproteins with asparagine-linked glycans (oligosaccharides) are found in vacuoles, in the extracellular space or matrix, and associated with the endo-membrane system (endoplasmic reticulum, Golgi apparatus, plasma membrane, tonoplast). These glycans are of the high-mannose type, with a structure identical to that found in other organisms (mammals, yeast), or of the complex type with a β1–2 linked xylosyl residue not found in mammalian complex glycans. Asparagine-linked glycans play multiple roles by modifying the physicochemical properties of the polypeptides to which they are attached.