The α‐isoform of glycogen synthase kinase‐3 from rabbit skeletal muscle is inactivated by p70 S6 kinase or MAP kinase‐activated protein kinase‐1 in vitro

FEBS Letters

Sutherland, Calum¹  Cohen, Philip¹ 

[1] MRC Protein Phosphorylation Unit, Department of Biochemistry, University of Dundee, Dundee DD1 4HN, Tayside, Scotland, UK

关键词: MAP kinase;    Ribosomal S6 kinase;    Glycogen synthase kinase-3;    Growth factor;    Insulin;   

DOI  :  10.1016/0014-5793(94)80112-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The α-isoform of glycogen synthase kinase-3 (GSK3α) was inactivated by 80% towards a synthetic peptide substrate upon incubation with Mg-ATP and either MAP kinase-activated protein (MAPKAP) kinase-1 or p70 S6 kinase. Inactivation by either kinase resulted from the phosphorylation of Ser-21 and was reversed by treatment with protein phosphatase 2A₁. Phosphorylation also decreased GSK3α activity towards glycogen synthase, inhibitor-2 and c-jun. The specificity of GSK3a was similar to GSK3β, but with the synthetic peptide substrate heparin stimulated the dephosphorylated form of GSK3α (6-fold) more than GSK3β(1.8-fold). After phosphorylation, both isoforms were stimulated 15–20-fold by heparin.

【 授权许可】

Unknown