Vasopressin stimulated a 40% decrease in [32P]phosphatidylinositol 4,5-bisphosphate and a 15% decrease in [32P]phosphatidylinositol within 30 s of addition to hepatocytes prelabeled for 60 min with 32P. In hepatocytes prelabeled with [3H]inositol for 60 min, vasopressin produced 20% breakdown of phosphatidylinositol and 33% breakdown of phosphatidylinositol 4,5-bisphosphate within 30 s. There w...

Aminoglycoside interactions with various phospholipids were measured in three model systems and compared with the ototoxicities of the drugs: (a) competition for [14C]neomycin binding; (b) competition for 45Ca2+ binding; and (c) effect on surface pressure of monomolecular lipid films. The efficacies of the antibiotics in displacing neomycin from phosphatidylserine, phosphatidylinositol or phosp...

CDP-diacylglycerol synthase, phosphatidylinositol synthase, and phosphatidylinositol kinase activities were associated with post-Golgi apparatus secretory vesicles destined for the plasma membrane of Saccharomyces cerevisiae. These results suggest that the plasma membrane is capable of synthesizing both CDP-diacylglycerol and phosphatidylinositol as well as phosphorylating phosphatidylinositol.

The effects of growth phase and carbon source on membrane-associated phosphatidylinositol kinase in cell extracts of Saccharomyces cerevisiae were examined. Phosphatidylinositol kinase activity increased 2- and 2.5-fold in glucose- and glycerol-grown cells, respectively, in the stationary phase as compared with the exponential phase of growth. The increase in phosphatidylinositol kinase activit...