title: Modulation of mitochondrial metabolic function by phorbol 12-myristate 13-acetate through increased mitochondrial translocation of protein kinase Calpha in C2C12 myocytes.
abstract: Protein kinase C (PKC) agonists including phorbol 12-myristate 13-acetate (PMA) not only induce the redistribution of cytosolic PKC to various subcellular compartments but also activate the kinase domain of the protein. In the present study we have investigated the nature of mitochondrial PKC pool and its effects on mitochondrial function in cells treated with PMA. Treatment of C2C12 myoblasts, C6 glioma and COS7 cells with PMA resulted in a dramatic redistribution of intracellular PKCalpha pool, with large fraction of the protein pool sequestered in the mitochondrial compartment. We also observed mitochondrial PKCdelta accumulation in a cell restricted manner. The intramitochondrial localization was ascertained by using a combination of protection against protease treatment of isolated mitochondria and immunofluorescence microscopy. PMA-induced mitochondrial localization of PKCalpha was accompanied by increased mitochondrial PKC activity, altered cell morphology, disruption of mitochondrial membrane potential, decreased complex I and pyruvate dehydrogenase activities, and increased mitochondrial ROS production. All of these changes could be retarded by treatment with PKC inhibitors. These results show a direct role for PMA-mediated PKCalpha translocation to mitochondria in inducing mitochondrial toxicity.
authors.affiliation: Laboratories of Biochemistry, Department of Animal Biology and The Mari Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Gopa
authors.initials: G
authors.lastname: Biswas
authors.forename: Subbuswamy K
authors.initials: SK
authors.lastname: Prabu
authors.forename: Narayan G
authors.initials: NG
authors.lastname: Avadhani
mesh_terms: D000818:Animals; D019556:COS Cells; D002227:Carbazoles / Q000494:pharmacology; D002245:Carbon Dioxide / Q000378:metabolism; D002250:Carbon Radioisotopes; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D004791:Enzyme Inhibitors / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D032342:Muscle Cells / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010703:Phorbol Esters / Q000494:pharmacology*; D051571:Protein Kinase C-alpha / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D011768:Pyruvate Dehydrogenase Complex / Q000037:antagonists & inhibitors / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D002227:Carbazoles; D002250:Carbon Radioisotopes; D004791:Enzyme Inhibitors; D007211:Indoles; D008301:Maleimides; D010703:Phorbol Esters; D011768:Pyruvate Dehydrogenase Complex; D017382:Reactive Oxygen Species; D011993:Recombinant Fusion Proteins; C081021:Go 6976; D002245:Carbon Dioxide; D049452:Green Fluorescent Proteins; C008874:phorbol-12,13-diacetate; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; C070515:bisindolylmaleimide I