Phospholipase D is activated and phosphorylated by casein kinase-II in human U87 astroglioma cells.
Elevated expression of protein casein kinase II (CKII) stimulated basal phospholipase D (PLD) activity as well as PMA-induced PLD activation in human U87 astroglioma cells. Moreover, CKII-selective inhibitor, emodin and apigenin suppressed PMA-induced PLD activation in a dose-dependent manner as well as basal PLD activity, suggesting the involvement of CKII in the activation of both PLD1 and PLD2. CKII was associated with PLD1 and PLD2 in co-transfection experiments. Furthermore, CKII induced serine/threonine phosphorylation of PLD2 in vivo, and the multiple regions of PLD2 were phosphorylated by CKII in vitro kinase assay using glutathione S-transferase-PLD2 fusion protein fragments. Elevated expression of CKII or PLD increased cell proliferation but pretreatment of cells with 1-butanol suppressed CKII-induced cell proliferation. These results suggest that CKII is involved in proliferation of U87 cells at least in part, through stimulation of PLD activity.
Ahn
Bong-Hyun
BH
Cardiovascular Branch National Heart, Lung and Blood Institute (NHLBI), NIH Bldg 10/CRC 5-3288, 10 Center Drive, Bethesda, MD 20892, USA.
Min
Gyesik
G
Bae
Yoe-Sik
YS
Bae
Young-Seuk
YS
Min
Do Sik
DS
D020001:1-Butanol / Q000494:pharmacology; D001254:Astrocytoma / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology; D015153:Blotting, Western; D047390:Casein Kinase II / Q000032:analysis / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011233:Precipitin Tests; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D004791:Enzyme Inhibitors; D011993:Recombinant Fusion Proteins; D020001:1-Butanol; D005982:Glutathione Transferase; D047390:Casein Kinase II; D010739:Phospholipase D; D013755:Tetradecanoylphorbol Acetate