Agonist-induced ADP-ribosylation of a cytosolic protein in human platelets.
alpha-Thrombin and phorbol 12,13-dibutyrate stimulated the mono(ADP-ribosyl)ation of a 42-kDa cytosolic protein of human platelets. This effect was mediated by protein kinase C activation and was inhibited by protein kinase C inhibitor staurosporine. It also was prevented by prostacyclin, which is known to inhibit the phospholipase C-induced formation of 1,2-diacylglycerol, which is one of the endogenous activators of protein kinase C. On sodium dodecyl sulfate/polyacrylamide gel electrophoresis, the 42-kDa protein that is ADP-ribosylated by alpha-thrombin was clearly distinct from the alpha subunits of membrane-bound inhibitory and stimulatory guanine nucleotide-binding regulatory proteins, respectively Gi alpha and Gs alpha; the 47-kDa protein that is phophorylated by protein kinase C in platelets; and the 39-kDa protein that has been shown to be endogenously ADP-ribosylated by agents that release nitric oxide. This information shows that agonist-induced activation of protein kinase leads to the ADP-ribosylation of a specific protein. This covalent modification might have a functional role in platelet activation.
Brüne
B
B
Division of Cell Biology, Burroughs Wellcome Company, Research Triangle Park, NC 27709.
Molina y Vedia
L
L
Lapetina
E G
EG
D000246:Adenosine Diphosphate Ribose / Q000097:blood; D000470:Alkaloids / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D001798:Blood Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002463:Cell Membrane Permeability; D002772:Cholera Toxin / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008970:Molecular Weight; D009243:NAD / Q000097:blood*; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology*; D019311:Staurosporine; D013917:Thrombin / Q000494:pharmacology*
D000470:Alkaloids; D001798:Blood Proteins; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D015240:Phorbol 12,13-Dibutyrate; D002772:Cholera Toxin; D013917:Thrombin; D019311:Staurosporine