Epidermal fucosylation of cell surface glycoprotein.

When Ulex europeus agglutinin I (UEA) conjugated with fluorescein isothiocyanate is applied to tissue sections from the cutaneous epidermis of the newborn rat, the lectin binds to the surfaces of cells in the layer immediately above the basal layer but not to the cells in the basal layer itself. The latter cells bind the isolectin I-B4, from Griffonia simplicifolia (GS I-B4). The addition of a fucosyl residue to the oligosaccharide of the glycoprotein found on the surface of the basal cell can account for the change in lectin-binding specificity which occurs as the basal cell moves toward the cutaneous surface and becomes a spinous cell. The epidermis of the newborn rat has the necessary transferase to convert a glycoprotein with binding-specificity for GS I-B4 to binding specificity for UEA by adding a fucosyl residue from GDP-L-fucose.