ISOFORM-SPECIFIC REDISTRIBUTION OF PROTEIN-KINASE-C IN LIVING CELLS

We have used confocal laser scanning microscopy to determine the dynam ics of distribution of activated protein kinase C (PKC) in living Madi n Darby canine kidney (MDCK) cells. Using fluorescently tagged phorbol myristate acetate (PMA) as a probe for PKC we have demonstrated its d istribution in association with the cell periphery and with the nucleu s, Dual labeling experiments using PKC alpha and PKC beta II specific antisera indicate that activated PKC alpha is found in association wit h the periphery whereas activated PKC beta II is translocated to the n ucleus. We have demonstrated increased activity of PKC in nuclear frac tions isolated from cells treated with PMA and other PKC activators. T hese data indicate that upon activation individual isoforms of PKC tra nslocate to different subcellular locations where they are likely to m ediate different actions.