Oligodendrocytes produce low molecular weight glycoproteins containing N-acetyl-D-glucosamine in their Golgi apparatus

Abstract
Lectin histochemistry using the Griffonia simplicifolia II lectin (GSL II) has revealed a novel group of glycoproteins containing terminal N‐acetyl‐D‐glucosamine (GlcNAc) residues in oligodendrocytes. The GlcNAc‐containing glycoproteins were not present in other types of glial cells, but were expressed by some neuronal cell populations. Within oligodendrocytes their localization was confined to the Golgi apparatus, as determined ultrastructurally. Biochemical analyses using tricine/SDS‐polyacrylamide gel electrophoresis and western blotting with GSL II showed the GlcNAc‐containing glycoproteins to be insoluble, with molecular masses ranging from 15 to 30 kDa. Our study provides a first account of insoluble, GlcNAc‐rich 15–30 kDa glycoproteins in oligodendroglia. The findings are discussed in the context of the functional significance of other known oligodendrocyte glycoproteins.