PHORBOL ESTER-INDUCED CHANGES IN RAT HIPPOCAMPAL GLYCOPROTEIN FUCOSYLATION

Studies on glycoprotein fucosylation were carried out using hippocampal slices from rat brain. These slices were incubated in the presence of the protein kinase C (PKC) activating phorbol ester, 4-beta-phorbol-12,13-dibutyrate (PDBu), or an inactive isoform, 4-alpha-phorbol-12,13-didecanoate (PDD), respectively, for 7 min followed by a 60 min pulse of [H-3]fucose. PDBu caused an increase in [H-3]fucose incorporation into glycoproteins by 29% as well as an activation of the fucokinase enzyme reaction by 21%. The PDBu-induced stimulation of [H-3]fucose insertion into hippocampal glycoproteins was abolished by the PKC inhibitors, staurosporine and H7. The importance of a PKC-regulated glycoprotein fucosylation in mechanisms underlying changes in neuronal plasticity is discussed.