Platelet-activating factor stimulation of p125(FAK) and p130(Cas) tyrosine phosphorylation in brain.
The effect of platelet-activating factor (PAF) on protein tyrosine phosphorylation was studied in rat brain slices. PAF induced a time- and concentration-dependent increase in tyrosine phosphorylation of a doublet of approximately 125 kDa. These proteins were identified by immunoprecipitation as p125(FAK) and p130(Cas), using monoclonal antibodies. This effect was mediated by PAF receptors, as shown by its inhibition by the action of a PAF antagonist. The tyrosine phosphorylation evoked by PAF was dependent, at least in part, on external calcium. The involvement of protein kinase C was demonstrated by the synergistic effect of TPA on PAF-stimulated tyrosine phosphorylation. The finding that PAF stimulates tyrosine phosphorylation of both focal adhesion protein p125(FAK) and p130(Cas) suggests that PAF might modulate the integrin mediated signal transduction in the brain.
Departamento de Bioquímica y Biología Molecular I, Facultad de Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain.
M C
MC
Calcerrada
R E
RE
Catalán
M J
MJ
Pérez-Alvarez
B G
BG
Miguel
A M
AM
Martínez
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D050719:Crk-Associated Substrate Protein; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D066298:In Vitro Techniques; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D010972:Platelet Activating Factor / Q000494:pharmacology*; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins; D051381:Rats; D050717:Retinoblastoma-Like Protein p130; D013268:Stimulation, Chemical
C493843:Bcar1 protein, rat; D015815:Cell Adhesion Molecules; D050719:Crk-Associated Substrate Protein; D010750:Phosphoproteins; D010972:Platelet Activating Factor; D011506:Proteins; D050717:Retinoblastoma-Like Protein p130; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496052:Ptk2 protein, rat