Subtype-specific translocation of the delta subtype of protein kinase C and its activation by tyrosine phosphorylation induced by ceramide in HeLa cells.
We investigated the functional roles of ceramide, an intracellular lipid mediator, in cell signaling pathways by monitoring the intracellular movement of protein kinase C (PKC) subtypes fused to green fluorescent protein (GFP) in HeLa living cells. C(2)-ceramide but not C(2)-dihydroceramide induced translocation of delta PKC-GFP to the Golgi complex, while alpha PKC- and zeta PKC-GFP did not respond to ceramide. The Golgi-associated delta PKC-GFP induced by ceramide was further translocated to the plasma membrane by phorbol ester treatment. Ceramide itself accumulated to the Golgi complex where delta PKC was translocated by ceramide. Gamma interferon also induced the delta PKC-specific translocation from the cytoplasm to the Golgi complex via the activation of Janus kinase and Mg(2+)-dependent neutral sphingomyelinase. Photobleaching studies showed that ceramide does not evoke tight binding of delta PKC-GFP to the Golgi complex but induces the continuous association and dissociation of delta PKC with the Golgi complex. Ceramide inhibited the kinase activity of delta PKC-GFP in the presence of phosphatidylserine and diolein in vitro, while the kinase activity of delta PKC-GFP immunoprecipitated from ceramide-treated cells was increased. The immunoprecipitated delta PKC-GFP was tyrosine phosphorylated after ceramide treatment. Tyrosine kinase inhibitor abolished the ceramide-induced activation and tyrosine phosphorylation of delta PKC-GFP. These results suggested that gamma interferon stimulation followed by ceramide generation through Mg(2+)-dependent sphingomyelinase induced delta PKC-specific translocation to the Golgi complex and that translocation results in delta PKC activation through tyrosine phosphorylation of the enzyme.
Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Nada-ku, Kobe 657-8501, Japan.
T
T
Kajimoto
S
S
Ohmori
Y
Y
Shirai
N
N
Sakai
N
N
Saito
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D016466:CHO Cells; D002458:Cell Fractionation; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002518:Ceramides / Q000378:metabolism* / Q000494:pharmacology; D006224:Cricetinae; D004075:Diglycerides / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006056:Golgi Apparatus / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D007371:Interferon-gamma / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism*; D008164:Luminescent Proteins / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D010703:Phorbol Esters / Q000494:pharmacology; D010718:Phosphatidylserines / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D011493:Protein Kinase C / Q000378:metabolism*; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D013997:Time Factors; D014443:Tyrosine / Q000378:metabolism*; D000099221:Protein Kinase C zeta
D000970:Antineoplastic Agents; D002518:Ceramides; D004075:Diglycerides; D004791:Enzyme Inhibitors; D049452:Green Fluorescent Proteins; D007371:Interferon-gamma; D007527:Isoenzymes; D008164:Luminescent Proteins; D008274:Magnesium; D010703:Phorbol Esters; D010718:Phosphatidylserines; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; D011993:Recombinant Fusion Proteins; D013108:Sphingomyelin Phosphodiesterase; D013110:Sphingosine; D014443:Tyrosine; D000099221:Protein Kinase C zeta; C064769:N-acetylsphingosine; C109343:dihydroceramide; C496628:PRKCA protein, human; C497258:PRKCD protein, human; C013965:diolein