Regulation of a liver plasma membrane phosphoinositide phosphodiesterase by guanine nucleotides and calcium

FEBS Letters

Exton, John H.¹  Prpic, Veronica¹  Jiang, Hang¹  Uhing, Ronald J.¹ 

[1] Laboratories for the Studies of Metabolic Disorders, Howard Hughes Medical Institute and the Department of Physiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA

关键词: Inositol trisphosphate;    Phosphatidylinositol bisphosphate;    Hormone;    Guanine nucleotide;    Calcium;    IP3;    myo-inositol trisphosphate;    IP2;    myo-inositol bisphosphate;    IP;    myo-inositol phosphate;    PI;    phosphatidylinositol;    PIP;    phosphatidylinositol 4-phosphate;    PIP2;    phosphatidylinositol 4;    5-bisphosphate;    GTPγS;    guanosine 5'-O-(thiotriphosphate);    GMPPNP;    guanyl-5'-yl imidodiphosphate;    GMPPCP;    guanyl-5 '-yl-(β;    γ-methylene)diphosphonate;   

DOI  :  10.1016/0014-5793(85)80394-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Rat liver plasma membranes are enriched in a Ca²⁺-dependent phosphodiesterase active on phosphatidylinositol 4,5-P₂ and phosphatidylinositol 4-P, but not phosphatidylinositol. Inositol-P₃ is the first product of the reaction, but is rapidly degraded. Micromolar concentrations of GTP and its nonhydrolyzable analogues stimulate the reaction, whereas GDP, GMP and other nucleoside triphosphates are inactive. GTP and its analogues decrease the requirement of the reaction for Ca²⁺ and also increase its activity at saturating Ca²⁺. These results support the hypothesis that guanine nucleotides and a guanine nucleotide binding regulatory protein are involved in coupling the receptors for Ca²⁺-mediated agonists to the breakdown of plasma membrane phosphatidylinositol 4,5-P₂.

【 授权许可】

Unknown