Inhibition of PI-kinase in rat liver membranes by F-.
In a number of membrane preparations GTP or its non-hydrolysable analogues stimulate the breakdown of PIP2 generating the second messengers, inositol triphosphate and diacylglycerol. The G-protein which couples the PIP2-specific phospholipase C with the receptors can also be activated by F-. However, the level of PIP2 is dependent upon the activity of a number of enzymes in the PI-pathway. Besides stimulating the breakdown of PIP2, we report that in rat liver membranes F- also decreases the labelling of the polyphosphoinositides through inhibition of the PI-kinase.
Biffen
M
M
Department of Biochemistry, University of Cambridge, U.K.
Martin
B R
BR
D019870:1-Phosphatidylinositol 4-Kinase; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D005459:Fluorides / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols / Q000378:metabolism*; D010770:Phosphotransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051381:Rats
D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; D019870:1-Phosphatidylinositol 4-Kinase; D019204:GTP-Binding Proteins; D005459:Fluorides