Endothelin stimulates tyrosine phosphorylation of p125FAK and p130Cas in rat cerebral cortex.
Stimulation of rat cerebral cortex with endothelin-1 (ET-1) caused an increase in the tyrosine phosphorylation of several proteins. Two of these phosphoproteins were identified by the immunoprecipitation assays as being the focal adhesion kinase p125FAK and crk-associated substrate p130Cas. This effect was time- and dose-dependent, with an EC50 value of 3.9 x 10(-8) M. In addition, the cerebral cortex ET receptor subtype involved in this action was determined by using BQ-123 and BQ-788, which are ET(A) and ET(B) receptor antagonists respectively. Our results indicate that the ET-1 effect on protein tyrosine phosphorylation occurred through ET(B) receptors. The requirement for extracellular Ca2+ on ET-1 action was also studied. ET-1-stimulated tyrosine phosphorylation of both p125FAK and p130Cas was abolished in the absence of external Ca2+ or in the presence of nimodipine, a Ca2+ channel-blocker. These results suggest that the ET-1-stimulated protein tyrosine phosphorylation was secondary to Ca2+ influx through the dihydropyridine Ca2+-channel. In slices where protein kinase C was inhibited, ET-1-stimulated tyrosine phosphorylation of both proteins was reduced. These results indicate that ET-1 modulates the tyrosine phosphorylation of specific proteins, which may be involved in adhesion processes in the brain.
Departamento de Bioquímica y Biología Molecular I, Facultad de Químicas, Universidad Complutense de Madrid, Spain.
M J
MJ
Pérez
M C
MC
Calcerrada
R E
RE
Catalán
A M
AM
Martínez
D000818:Animals; D002118:Calcium / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D050719:Crk-Associated Substrate Protein; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1 / Q000494:pharmacology*; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D008297:Male; D009842:Oligopeptides / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D010880:Piperidines / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins; D051381:Rats; D017208:Rats, Wistar; D050717:Retinoblastoma-Like Protein p130; D014443:Tyrosine / Q000378:metabolism*
C493843:Bcar1 protein, rat; D015815:Cell Adhesion Molecules; D050719:Crk-Associated Substrate Protein; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D009842:Oligopeptides; D010456:Peptides, Cyclic; D010750:Phosphoproteins; D010880:Piperidines; D011506:Proteins; D050717:Retinoblastoma-Like Protein p130; D014443:Tyrosine; C086539:BQ 788; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496052:Ptk2 protein, rat; C072247:cyclo(Trp-Asp-Pro-Val-Leu); D002118:Calcium