PROTEIN-KINASE-C DELTA-SUBSPECIES AND EPSILON-SUBSPECIES IN RAT CENTRAL NERVOUS-TISSUE - DIFFERENTIAL DISTRIBUTION AND PHORBOL ESTER-INDUCED REDISTRIBUTION IN SYNAPTOSOMES

Distribution of the delta- and epsilon-subspecies of protein kinase C (PKC) in rat central nervous tissues was semiquantitated by an immunob lot analysis. The epsilon-subspecies, which is expressed predominantly in the brain, was abundant in hippocampus and cerebral cortex among r at brain areas, whereas the delta-subspecies, which is expressed ubiqu itously in many tissues, showed no significant difference among tissue areas tested. Unlike other subspecies, the delta-subspecies was prima rily associated with particulate fractions. Subcellular fractionation analysis revealed that both the epsilon- and delta-subspecies were enr iched in the synaptosomal P-2 fraction. Treatment with 12-O-tetradecan oyl-phorbol 13-acetate (TPA) induced translocation of the epsilon-subs pecies from cytosolic fraction to membrane fraction. In contrast, upon treatment with TPA, the delta-subspecies normally bound to membrane f raction was released into cytosol.