The Ca2+-activated polyphosphoinositide phosphodiesterase of human and rabbit neutrophil membranes.
Addition of Ca2+ to a plasma-membrane fraction derived from human or rabbit neutrophils led to the specific breakdown of polyphosphoinositides. The degradation products were identified as diacylglycerol and inositol bis- and tris-phosphate, thus demonstrating the presence of a Ca2+-activated phospholipase C. The newly generated diacylglycerol resembled the polyphosphoinositides in its fatty acid composition, and in the presence of MgATP2- it was converted into phosphatidate. These results therefore demonstrate the presence in neutrophil plasma membranes not only of polyphosphoinositide phosphodiesterase but also of diacylglycerol kinase.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D019852:Diacylglycerol Kinase; D005227:Fatty Acids / Q000032:analysis; D006801:Humans; D006868:Hydrolysis; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology*; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols / Q000378:metabolism; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D010770:Phosphotransferases / Q000378:metabolism; D011817:Rabbits
D005227:Fatty Acids; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; D010770:Phosphotransferases; D019852:Diacylglycerol Kinase; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D002118:Calcium