title: FcepsilonRI cross-linking activates a type II phosphatidylinositol 4-kinase in RBL 2H3 cells.
abstract: Crosslinking of FcepsilonRI on rat basophilic leukemia (RBL 2H3) cells leads to an increase in Phosphatidylinositol 4-kinase activity. This increase in Ptdlns 4-kinase activity is strongly correlated with its tyrosyl phosphorylation state. Characterization of the enzyme activity in anti phosphotyrosine immunoprecipitates suggests it as a type II Ptdlns 4-kinase. Membrane cholesterol depletion studies showed a reduction in type II Ptdlns 4-kinase activity suggesting that lipid rafts play an important role in activation of the enzyme. The enzyme activity was inhibited by resveratrol. In situ inhibition of type II Ptdlns 4-kinase activity showed a reduction in beta-hexosaminidase release upon FcepsilonRI cross-linking. These studies suggest that a type II Ptdlns 4-kinase is an integral component of FcepsilonRI mediated signal transduction mechanisms.
authors.affiliation: Biotechnology Group, School of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400076, India.
authors.forename: Bojjireddy
authors.initials: B
authors.lastname: Naveen
authors.forename: Bhavani S
authors.initials: BS
authors.lastname: Shankar
authors.forename: Gosukonda
authors.initials: G
authors.lastname: Subrahmanyam
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006969:Hypersensitivity, Immediate / Q000201:enzymology; D008407:Mast Cells / Q000201:enzymology* / Q000276:immunology; D021962:Membrane Microdomains / Q000378:metabolism; D051381:Rats; D017455:Receptors, IgE / Q000276:immunology / Q000378:metabolism*; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology; D047392:beta-Cyclodextrins / Q000494:pharmacology; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D017455:Receptors, IgE; D013267:Stilbenes; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D002784:Cholesterol; D019870:1-Phosphatidylinositol 4-Kinase; D001619:beta-N-Acetylhexosaminidases; D000077185:Resveratrol