Rapid assay of binding of tumor-promoting phorbol esters to protein kinase C1.
Protein kinase C is generally accepted to be a receptor protein of tumor-promoting phorbol esters. The binding of [3H]phorbol-12,13-dibutyrate to protein kinase C can be assayed by a rapid filtration procedure using a glass-fiber filter that has been treated with a cationic polymer, polyethylenimine. The phorbol ester specifically binds to the protein kinase only in the presence of phosphatidylserine and calcium. Non-specific binding is less than 10%, at most, of the total binding. The binding is linear with respect to the concentration of protein kinase C, is dependent on the concentrations of phorbol ester and phosphatidylserine in a saturative manner, and is inhibited by diacylglycerol (an endogenous activator of the protein kinase).
Tanaka
Y
Y
Miyake
R
R
Kikkawa
U
U
Nishizuka
Y
Y
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D002118:Calcium / Q000494:pharmacology; D002850:Chromatography, Gel; D004075:Diglycerides / Q000494:pharmacology; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000378:metabolism*; D010718:Phosphatidylserines / Q000494:pharmacology; D011485:Protein Binding; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats
D004075:Diglycerides; D010703:Phorbol Esters; D010718:Phosphatidylserines; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D002118:Calcium