Molecular basis for the substrate specificity of protein kinase B; comparison with MAPKAP kinase‐1 and p70 S6 kinase

FEBS Letters

Barry Caudwell, F.¹  Alessi, Dario R.¹  Andjelkovic, Mirjana²  Hemmings, Brian A.²  Cohen, Philip¹ 

[1] MRC Protein Phosphorylation Unit, Department of Biochemistry, University of Dundee, Dundee DD1 4HN, UK;Friedrich Miescher Institute, PO BOX 2543, CH 4002 Basel, Switzerland

关键词: Protein kinase B;    Akt or RAC kinase;    Insulin;    PI 3-kinase;    Kinase specificity;    Kinase substrate;    S6 kinase;    PKB;    protein kinase B;    PI 3-kinase;    phosphonositide 3-kinase;    MAPKAP-kinase-1;    MAP kinase activated protein kinase-1;    PH;    pleckstrin homology;    HA;    haemagglutinin;    PKA;    cyclic AMP-dependent protein kinase;    PKC;    protein kinase C;   

DOI  :  10.1016/S0014-5793(96)01370-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The substrate specificity of protein kinase-Bα (PKBα, also known as RAC kinase or Akt) was investigated using synthetic peptide substrates related to the sequence surrounding the phosphorylation site on glycogen synthase kinase-3 (GSK3). The minimum sequence motif required for efficient phosphorylation was Arg-Xaa-Arg-Yaa-Zaa-Ser/Thr-Hyd, where Xaa is any amino acid, Yaa and Zaa are small residues other than glycine and Hyd is a bulky hydrophobic residue (Phe, Leu). The most effective substrate, Arg-Pro-Arg-Thr-Ser-Ser-Phe, was phosphorylated with a K _m of 5 μM and V_max of 260 U/mg. PKBα phosphorylated histone H2B (K _m 5 μM, V _max 68 Ulmg) specifically at Ser-36 which also lies in an Arg-Xaa-Arg-Xaa-Xaa-Ser-Hyd motif. The peptide Arg-Pro-Arg-Ala-Ala-Thr-Phe may be a relatively specific substrate for PKBα because, unlike other substrates, it is not phosphorylated by p70 S6 kinase or MAP kinase activated protein (MAPKAP) kinase-1.

【 授权许可】

Unknown