Involvement of PKC-alpha in PMA-induced facilitation of exocytosis and vesicle fusion in PC12 cells

Abstract

Phorbol-12-myristate-13-acetate, a stable analog of the important signaling membrane lipid diacylglycerol (DAG), is known to potentiate exocytosis and modulate vesicle fusion kinetics in neurons and endocrine cells. The exact mechanisms underlying the actions of PMA, however, is often not clear, largely

because of the diversity of the DAG/PMA receptors involved in the exocytotic process, which include, most notably, various isoforms of protein kinase C (PKC). In this study, the roles of PKCa in PMA-mediated regulation of exocytosis were investigated by over-expressing wild-type PKCa (wt-PKCa) or

dominant negative PKCa (dn-PKCa). Amperometric measurements based on carbon fiber microelectrodes

demonstrated that PKCa has a key role in the PMA-mediated facilitation of exocytosis and vesicle fusion in neuroendocrine PC12 cells.