Phosphorylation of JAK2 in thrombin‐stimulated human platelets

FEBS Letters

Watson, Steve P.¹  Rodríguez-Liñares, Belén¹ 

[1] Department of Pharmacology, Mansfield Road, Oxford, OX1 3QT, UK

关键词: JAK2;    Tyrosine kinase;    Human platelet;    Tyrosine phosphorylation;    BAPTA-AM;    1;    2-bis(2-aminophenoxy)ethane-N;    N;    N′;    N′-tetraacetic acetoxymethylester;    DG;    diacylglycerol;    PKC;    protein kinase C;    IP3;    inosotol 1;    4;    5-trisphosphate;    PDBu;    phorbol dibutyrate;    TBS-T;    Tris buffered saline-Tween;    SDS-PAGE;    sodium dodecyl sulphate-polyacrylamide gel electrophoresis;    BSA;    bovine serum albumin;    PMSF;    phenylmethanesulphonyl diflouride;   

DOI  :  10.1016/0014-5793(94)00983-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We show the presence of the tyrosine kinase JAK2 in human platelets and demonstrate that it undergoes phosphorylation on tyrosine residues on challenge with the G protein receptor stimulus, thrombin, or the tyrosine phosphatase inhibitor, peroxovanadate. Thrombin-induced phosphorylation of JAK2 is inhibited by two structurally distinct inhibitors of tyrosine kinases, staurosporine and the tyrphostin ST271. The protein kinase C (PKC) inhibitor, Ro 31-8220, and intracellular Ca²⁺ chelator, BAPTA-AM, also inhibit thrombin-induced phosphorylation of JAK2, while the phorbol ester, phorbol dibutyrate (PDBu), and Ca²⁺ ionophore, A23187, induce tyrosine phosphorylation of JAK2. These results suggest that tyrosine phosphorylation of JAK2 stimulated by thrombin may be mediated downstream of phosphoinositide metabolism.

【 授权许可】

Unknown