The lectin wheat germ agglutinin stimulates a protein-tyrosine kinase activity of p72syk in porcine splenocytes.
We previously reported a molecular cloning of porcine gene syk encoding a non-receptor type 72-kDa protein-tyrosine kinase and a generation of anti-CPTK40 antibodies which could immunoprecipitate the activity of p72syk (Taniguchi et al. (1991) J. Biol. Chem. 266, 15790-15796). In this study, we have demonstrated that wheat germ agglutinin caused an increase in the autophosphorylation activity of p72syk which preceded an increase of protein-tyrosine phosphorylation observed at the same time in porcine splenocyte. The increase of p72syk activity was dose dependent and was inhibited by the coexistence of N-acetyl-D-glucosamine. Upon stimulation by the combination of 4 beta-phorbol 12-myristate 13-acetate and ionophore A23187, we could not detect the increase of activity of p72syk suggesting that the activation of p72syk was independent of protein kinase C and calcium ions.
Yamada
T
T
Department of Biochemistry, Fukui Medical School, Japan.
Taniguchi
T
T
Nagai
K
K
Saitoh
H
H
Yamamura
H
H
D000117:Acetylglucosamine / Q000494:pharmacology; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D008214:Lymphocytes / Q000187:drug effects / Q000201:enzymology*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D013154:Spleen / Q000187:drug effects / Q000201:enzymology*; D013552:Swine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014909:Wheat Germ Agglutinins
D014909:Wheat Germ Agglutinins; D000001:Calcimycin; D011505:Protein-Tyrosine Kinases; D013755:Tetradecanoylphorbol Acetate; D000117:Acetylglucosamine