in the presence of extracellular calcium , vasopressin stimulates the phosphorylation of a 45,000-dalton protein and to a lesser degree of a 20,000-dalton protein following a pattern observed with thrombin and 12-o-tetradecanoylphorbol-13-acetate , a phorbol ester .
C0039654
12-o-tetradecanoylphorbol-13-acetate
C0031586
phorbol ester