Thromb Haemost 1994; 72(06): 937-941
DOI: 10.1055/s-0038-1648987
Original Article
Schattauer GmbH Stuttgart

Protein-tyrosine Kinase p72 syk Is Activated by Platelet Activating Factor in Platelets

Karim Rezaul
The Department of Biochemistry, Fukui Medicial School, Matsuoka, Fukui, Japan
,
Shigeru Yanagi
The Department of Biochemistry, Fukui Medicial School, Matsuoka, Fukui, Japan
,
Kiyonao Sada
The Department of Biochemistry, Fukui Medicial School, Matsuoka, Fukui, Japan
,
Takanobu Taniguchi
The Department of Biochemistry, Fukui Medicial School, Matsuoka, Fukui, Japan
,
Hirohei Yamamura
1   Biosignal Research Center, Kobe University, Kobe, Japan
› Author Affiliations
Further Information

Publication History

Received 19 April 1994

Accepted after resubmission 30 August 1994

Publication Date:
06 July 2018 (online)

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Summary

It has been demonstrated that activation of platelets by platelet-activating factor (PAF) results in a dramatic increase in tyrosine phosphorylation of several cellular proteins. We report here that p72 syk is a potential candidate for the protein-tyrosine phosphorylation following PAF stimulation in porcine platelets. Immunoprecipitation kinase assay revealed that PAF stimulation resulted in a rapid activation of p72 syk which peaked at 10 s. The level of activation was found to be dose dependent and could be completely inhibited by the PAF receptor antagonist, CV3988. Phosphorylation at the tyrosine residues of p72 syk coincided with activation of yllsyk. Pretreatment of platelets with aspirin and apyrase did not affect PAF induced activation of p72 syk .Furthermore, genistein, a potent protein-tyrosine-kinase inhibitor, diminished PAF-induced p72 syk activation and Ca2+ mobilization as well as platelet aggregation. These results suggest that p72 syk may play a critical role in PAF-induced aggregation, possibly through regulation of Ca2+ mobilization.