Activation of a cellular tyrosine‐specific protein kinase by phosphorylation

FEBS Letters

Swarup, Ghanshyam¹  Subrahmanyam, Gosukonda¹ 

[1]Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India

关键词: Tyrosine kinase;    Enzyme activation;    Rat spleen;    Autophosphorylation;   

DOI  :  10.1016/0014-5793(85)80889-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A tyrosine-specific protein kinase of M _r 56 000 was purified over 200-fold from rat spleen. Incubation of this kinase preparation with ATP and Mg²⁺ results in about 10-fold increase in the protein kinase activity. The activation of the kinase was unaffected in the presence of soyabean trypsin inhibitor. Polyacrylamide gel electrophoresis of the enzyme preparation after phosphorylation with ATP showed one phosphoprotein band of M _r 56 000. During purification of this kinase a large decrease in enzyme activity was observed which could be prevented by adding 10 μM vanadate, as inhibitor of tyrosine-specific protein phosphatases. These results suggest that the activation of the protein kinase by ATP is due to phosphorylation of the enzyme.

【 授权许可】

Unknown