Protein kinase C ? and ? mediate positive inotropy in adult ventricular myocytes

To examine cardiac contractile regulation and protein kinase C (PKC) translocation in parallel, the delta and epsilon isoforms of PKC were fused to green fluorescent protein (GFP) and expressed in adult rat ventricular myocytes maintained in short term culture. PKC-delta-GFP and PKC-epsilon-GFP were predominantly cytosolic until phorbol dibutyrate (PDBu) was introduced. PKC-delta-GFP redistributed preferentially to perinuclear structures that...