Function of N-glycosylation in plants

• Published in: Plant science (Limerick) 2018-09, Vol.274, p.70-79
• Main Authors: Nagashima, Yukihiro, von Schaewen, Antje, Koiwa, Hisashi
• Format: Article
• Language: English
• Subjects: Arabidopsis thaliana; Cellulose biosynthesis; Complex N-glycan; Protein N-glycosylation; Secretory pathway
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2018.05.007

•N-linked complex glycans of plant glycoproteins have unique structures containing core α1,3-fucose and β1,2-xylose residues.•Some receptor-like kinases are under regulation of the ER quality control pathway.•Salt tolerance that involves coordinated cellulose biosynthesis activities at the plasma membrane is specifically affected by loss of complex N-glycan maturation. Protein N-glycosylation is one of the major post-translational modifications in eukaryotic cells. In lower unicellular eukaryotes, the known functions of N-glycans are predominantly in protein folding and quality control within the lumen of the endoplasmic reticulum (ER). In multicellular organisms, complex N-glycans are important for developmental programs and immune responses. However, little is known about the functions of complex N-glycans in plants. Formed in the Golgi apparatus, plant complex N-glycans have structures distinct from their animal counterparts due to a set of glycosyltransferases unique to plants. Severe basal underglycosylation in the ER lumen induces misfolding of newly synthesized proteins, which elicits the unfolded protein response (UPR) and ER protein quality control (ERQC) pathways. The former promotes higher capacity of proper protein folding and the latter degradation of misfolded proteins to clear the ER. Although our knowledge on plant complex N-glycan functions is limited, genetic studies revealed the importance of complex N-glycans in cellulose biosynthesis and growth under stress.