Bradykinin-induced generation of inositol 1,4,5-trisphosphate in fibroblasts and neuroblastoma cells: effect of pertussis toxin, extracellular calcium, and down-regulation of protein kinase C.
The net content of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] was measured in bradykinin (BK)-stimulated NIH3T3 fibroblasts and neuroblastoma-glioma hybrid cells (NG108-15). BK-mediated production of Ins(1,4,5)P3 was not affected by replacing the medium with Ca2+-free medium, but addition of EGTA (1mM) to Ca2+-free medium markedly prevented production of Ins(1,4,5)P3. Although pertussis toxin (PT) treatment caused ADP-ribosylation in both NIH3T3 cells and NG108-15 cells, the BK-induced Ins(1,4,5)P3 formation was considerably reduced in the former cells but not in the latter cells, suggesting that PT-sensitive and PT-insensitive GTP-binding proteins are involved in phosphoinositide phospholipase C (PI-PLC) activation in fibroblasts and neuroblastoma cells, respectively. In NG108-15 cells down-regulated in protein kinase C (PKC) by long-term exposure to phorbol 12-myristate 13-acetate (PMA), BK-stimulated Ins(1,4,5)P3 accumulation was significantly enhanced compared to control cells.
Fu
T
T
Department of Biochemistry, Gifu University School of Medicine, Japan.
Okano
Y
Y
Nozawa
Y
Y
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D004789:Enzyme Activation; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism; D005910:Glioma / Q000378:metabolism; D006822:Hybrid Cells; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000096:biosynthesis*; D009447:Neuroblastoma / Q000378:metabolism*; D037342:Pertussis Toxin; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D013403:Sugar Phosphates / Q000096:biosynthesis*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D007295:Inositol Phosphates; D013403:Sugar Phosphates; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D015544:Inositol 1,4,5-Trisphosphate; D037342:Pertussis Toxin; D011493:Protein Kinase C; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D019204:GTP-Binding Proteins; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D013755:Tetradecanoylphorbol Acetate; D001920:Bradykinin; D002118:Calcium