The major form of protein tyrosine kinase in the dog prostate is expressed by a 50 kDa polypeptide

FEBS Letters

Chapdelaine, Alcide¹  Chevalier, Simone¹  Durocher, Yves¹  Nguyen, Linh T.¹ 

[1] Departments of Biochemistry and of Medicine, University of Montreal and Maisonneuve-Rosemont Research Center, Montréal, Canada

关键词: Canine prostate;    Tyrosine phosphorylation;    Autophosphorylation;    Renaturation;    PTK;    protein tyrosine kinase;    SDS;    sodium dodecyl sulfate;    PAGE;    polyacrylamide gel electrophoresis;    polyGT;    polymer of sodium glutamate and tyrosine;    pY;    phosphotyrosine;    pS;    phosphoserine;    pT;    phosphothreonine;    QMA;    quaternary methyl amine;    C18;    octadodecyl;    2D;    two-dimensional;   

DOI  :  10.1016/0014-5793(92)80382-Q

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have already reported that the protein tyrosine kinase (PTK) activity in the dog prostate is distributed in cytosolic (75%) and particulate (Triton X-100-solubilized) fractions and that upon gel filtration, both PTKs migrate as entities of M _r 44 000 [(1991) Biochem. Cell. Biol. 69, 146–153]. Herein we demonstrate by immunoprecipitation with anti-phosphotyrosine antibodies that the soluble PTK has the ability to undergo self-phosphorylation. In addition, the polypeptide responsible for that enzymatic activity has been identified by 2 approaches; (1) a two-dimensional electrophoresis, in which the first dimension performed in non-denaturing conditions allowed the localization of the native enzyme, while the second dimension (SDS-PAGE) permitted the analysis of alkali-resistant phosphoproteins corresponding to the activity; (2) protein renaturation after SDS-PAGE followed by in situ phosphorylation (with [γ-³²P]ATP) of polyGT electrophoresed together with the enzyme preparation; the exclusive presence of the radiolabeled phosphotyrosine in the renatured protein confirmed its enzymatic nature. Using these methods, the major form of PTK in the dog prostate was shown to be expressed by a 50 kDa polypeptide which possesses autophosphorylation sites and which is present in the cytosol as an active monomer.

【 授权许可】

Unknown