Protein Kinase C Regulates Mitochondrial Motility

Functions of mitochondria depend on their intracellular localization, which often coincides with regions of the highest ATP consumption. Transport of mitochondria along microtubules and actin microfilaments and their anchoring by cytoskeletal structures are regulated by exogenous and endogenous factors. Changes in mitochondrial motility induced by protein kinase C activity modulators were studied using video microscopy of live fibroblasts expressing a GFP-tagged mitochondrial marker. Intracellular activation of protein kinase C by 12-O-tetradecanoylphorbol-13-acetate (TPA) significantly enhances mitochondrial mobility, whereas the protein kinase C inhibitor bis-indolylmaleimide fully suppresses it. The activating effect of TPA on mitochondrial movement is not due to rearrangements in the actin cytoskeleton, since it persists in cells treated with latrunculin B disrupting F-actin. No effect of TPA on mitochondrial mobility is observed in MFT-16 cells devoid of intermediate vimentin filaments. The data obtained suggest that protein kinase C regulates the interactions of mitochondria with intermediate filaments.