Evidence for a Ca2+-independent hydrolysis of phosphatidylinositol 4,5-bisphosphate in neuron-like cell line NG108-15 cells.
The addition of bradykinin to 32Pi-labeled neuroblastoma X glioma hybrid NG108-15 cells caused a substantial loss of radioactivity from phosphatidylinositol 4,5-bisphosphate (PI-4,5-P2). The bradykinin-induced hydrolysis of PI-4,5-P2 was almost equally observed even when extracellular Ca2+ was depleted with EGTA (100 microns). On the other hand, high K+ depolarization of the cells, which allows Ca2+ influx through voltage-dependent Ca2+ channels, failed to induce any significant decrease in the radioactivity of PI-4,5-P2. These data indicate that the bradykinin-stimulated PI-4,5-P2 hydrolysis in NG108-15 cells is independent of extracellular Ca2+ and also that PI-4,5-P2 hydrolysis is not stimulated by an elevation of intracellular Ca2+ concentration.
Yano
K
K
Higashida
H
H
Nozawa
Y
Y
D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D004533:Egtazic Acid / Q000494:pharmacology; D005910:Glioma / Q000378:metabolism*; D006822:Hybrid Cells / Q000378:metabolism*; D006868:Hydrolysis; D007473:Ion Channels / Q000378:metabolism; D009447:Neuroblastoma / Q000378:metabolism*; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D013997:Time Factors
D007473:Ion Channels; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols; D004533:Egtazic Acid; D011188:Potassium; D001920:Bradykinin; D002118:Calcium