Isoform-specific redistribution of protein kinase C in living cells.

We have used confocal laser scanning microscopy to determine the dynamics of distribution of activated protein kinase C (PKC) in living Madin Darby canine kidney (MDCK) cells. Using fluorescently tagged phorbol myristate acetate (PMA) as a probe for PKC we have demonstrated its distribution in association with the cell periphery and with the nucleus. Dual labeling experiments using PKC alpha and PKC beta II specific antisera indicate that activated PKC alpha is found in association with the periphery whereas activated PKC beta II is translocated to the nucleus. We have demonstrated increased activity of PKC in nuclear fractions isolated from cells treated with PMA and other PKC activators. These data indicate that upon activation individual isoforms of PKC translocate to different subcellular locations where they are likely to mediate different actions.