The lectin wheat germ agglutinin induces rapid protein-tyrosine phosphorylation in human platelets.
In response to wheat germ agglutinin (WGA), platelet aggregation and stimulation of protein-tyrosine phosphorylation were observed in a dose dependent manner. These reactions were completely inhibited by coexistence of N-acetyl-D-glucosamine with WGA. Upon stimulation by this agonist, protein-tyrosine phosphorylation of seven bands with molecular masses of 140-, 130-, 80-, 76-, 53-, 38- and 35-kDa proteins was observed by immunoblot. These protein-tyrosine phosphorylations were divided into three groups by kinetics. Considering the previous report from our laboratory that thrombin and collagen induced tyrosine phosphorylation in 135-, 124- and 76-kDa proteins (Nakamura, S. and Yamamura, H. (1989) J. Biol. Chem. 264, 7089-7091.), there may be another signal transduction pathway in tyrosine phosphorylation of human platelets.
Inazu
T
T
Department of Biochemistry, Fukui Medical School, Japan.
Taniguchi
T
T
Ohta
S
S
Miyabo
S
S
Yamamura
H
H
D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D001798:Blood Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D066298:In Vitro Techniques; D007700:Kinetics; D010766:Phosphorylation; D010974:Platelet Aggregation; D014443:Tyrosine; D014909:Wheat Germ Agglutinins / Q000494:pharmacology*
D001798:Blood Proteins; D014909:Wheat Germ Agglutinins; D014443:Tyrosine