Regulation of cardiac insulin receptor function by guanosine nucleotides

FEBS Letters

Russ, Martina¹  Reinauer, Hans¹  Eckel, Jürgen¹ 

[1] Laboratory of Molecular Cardiology, Diabetes Research Institute, 4000 Düsseldorf 1, Germany

关键词: Isolated cardiac myocyte;    Insulin receptor;    Guanosine nucleotide binding protein;    Tyrosine kinase;    GTP-γ-S;    guanosine 5'-O-(3-thiotriphosphate);    GDP-β-S;    guanosine 5'-O-(2-thiodiphosphate);    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;    HEPES;    4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid;    WGA;    wheat germ agglutinin;    AMP-PNP;    adenyl-5'-yl imidodiphosphate;   

DOI  :  10.1016/0014-5793(93)81518-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The present study examined the effect of GTP-γ-S on the function of insulin receptors partially purified from adult rat cardiomyocytes by WGA chromatography. GTP-γ-S increased receptor autophosphorylation about two times and fully mimicked the stimulatory action of insulin on poly(Glu:Tyr) phosphorylation with no additional effect of the hormone. The effect of GTP-γ-S was specific, dose-dependent, and due to an increase in the V _max of the kinase. In the presence of ATP or AMP-PNP, insulin significantly enhanced the binding of [⁵S]GTP-γ-S to the partially purified insulin receptor. The findings suggest coupling of the insulin receptor to a G-protein which may be involved in the regulation of tyrosine kinase activity.

【 授权许可】

Unknown