Presence of a novel form of phosphatidylinositol 4‐kinase in rat liver

FEBS Letters

Martínez-Arias, Wilma²  Drøbak, Bjørn K.¹  Olsson, Henric²  Jergil, Bengt² 

[1] Department of Cell Biology, John Innes Institute for Plant Science Research, Norwich, UK;Biochemistry, Chemical Centre, University of Lund, PO Box 124, S-221 00 Lund, Sweden

关键词: Signal transduction;    Phosphoinositide;    Phosphatidyl inositol 4-kinase;    Rat liver;    PtdIns;    phosphatidylinositol;    PtdIns4P;    phosphatidylinositol 4-phosphate;    PtdIns(4;    5)P2;    phosphatidylinositol 4;    5-bisphosphate;    PtdCho;    phos-phatidylcholine;    PtdSer;    phosphatidylserine;    GPtdInsP;    glycerophosphoryl-inositolphosphate;    CMC;    critical micelle concentration;   

DOI  :  10.1016/0014-5793(95)00194-E

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown