title: Intracellular lectins are involved in quality control of glycoproteins.
abstract: Glycoprotein quality control is categorized into three kinds of reactions; the folding of nascent glycoproteins, ER-associated degradation of misfolded or unassembled glycoproteins, and transport and sorting of correctly folded glycoproteins. In all three processes, N-glycans on the glycoproteins are used as tags that are recognized by intracellular lectins. We analyzed the functions of these intracellular lectins and their sugar-binding specificities. The results clearly showed that the A, B, and C-arms of high mannose-type glycans participate in the folding, transport and sorting, and degradation, respectively, of newly synthesized peptides. After correctly folded glycoproteins are transported to the Golgi apparatus, N-glycans are trimmed into Man3GlcNAc2 and then rebuilt into various complex-type glycans in the Golgi, resulting in the addition of diverse sugar structures that allow glycoproteins to play various roles outside of the cells.
authors: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo.
authors: Kazuo
authors: K
authors: Yamamoto
mesh_terms: D000818:Animals; D006023:Glycoproteins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism*; D037102:Lectins / Q000737:chemistry / Q000378:metabolism*; D017510:Protein Folding; D021381:Protein Transport
chemical_list: D006023:Glycoproteins; D037102:Lectins