These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Phosphatidic acid is a specific activator of phosphatidylinositol-4-phosphate kinase.
    Author: Moritz A, De Graan PN, Gispen WH, Wirtz KW.
    Journal: J Biol Chem; 1992 Apr 15; 267(11):7207-10. PubMed ID: 1313792.
    Abstract:
    The lipid dependence of phosphatidylinositol-4-phosphate (PIP) kinase purified from bovine brain membranes was investigated. In the assay used, PIP-Triton X-100 micelles containing the lipid to be tested were presented to the enzyme. Under these conditions, phosphatidic acid (PA) stimulated the enzyme activity in a concentration-dependent manner up to 20-fold when an equal molar ratio of PA to PIP was attained. Stimulation by PA was highly specific; other lipids including lyso-PA and dicetylphosphate had a relatively small effect. The activation by PA was completely suppressed by phosphatidylinositol 4,5-bisphosphate (PIP2). To investigate the effect of PA on PIP kinase activity in natural membranes, endogenous PA was generated in rat brain synaptosomal plasma membranes by incubation with phospholipase D. Subsequent phosphorylation with [gamma-32P]ATP yielded an enhanced labeling of PIP2 but not of PIP in these membranes. These results suggest that PIP kinase activity may be under control of PA levels in membranes. This may have important implications for the regulation of cellular responses by agonist-induced phosphoinositide turnover.
    [Abstract] [Full Text] [Related] [New Search]