title: Presence of a novel form of phosphatidylinositol 4-kinase in rat liver.
abstract: Rat liver microsomes contain two distinct forms of PtdIns 4-kinase which were resolved by heparin-Sepharose chromatography. One enzyme was identified as the type II PtdIns kinase previously isolated from exocytotic vesicles. The other enzyme, however, was a novel PtdIns 4-kinase isoform with properties differing from any other PtdIns kinase so far characterized. Both kinases were recognized by a monoclonal antibody specific for type II PtdIns 4-kinase, but the novel enzyme was considerably less sensitive to inhibition by adenosine and Ca2+ than type II enzymes, and in addition was specifically inhibited by submillimolar concentrations of dithioerythritol. The presence of a novel PtdIns 4-kinase isoform in rat liver raises the question of whether this enzyme is unique for this organ or whether it has a more widespread distribution but so far has avoided detection.
authors.affiliation: Chemical Centre, University of Lund, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Olsson
authors.forename: W
authors.initials: W
authors.lastname: Martínez-Arias
authors.forename: B K
authors.initials: BK
authors.lastname: Drøbak
authors.forename: B
authors.initials: B
authors.lastname: Jergil
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase; D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D002846:Chromatography, Affinity; D004226:Dithioerythritol / Q000494:pharmacology; D007527:Isoenzymes / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008862:Microsomes, Liver / Q000201:enzymology*; D010718:Phosphatidylserines / Q000494:pharmacology; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000302:isolation & purification* / Q000378:metabolism; D051381:Rats
chemical_list: D000911:Antibodies, Monoclonal; D002413:Cations, Divalent; D007527:Isoenzymes; D010718:Phosphatidylserines; D004226:Dithioerythritol; D017853:Phosphotransferases (Alcohol Group Acceptor); D019870:1-Phosphatidylinositol 4-Kinase; D000241:Adenosine; D002118:Calcium