using fibroblastic cells depleted of protein kinase c by chronic treatment with the tumor promoter tetradecanoyl phorbol acetate ( tpa ) , we now show that protein kinase c is required for the tyrosine phosphorylation of the 42-kd protein , even when epidermal growth factor ( egf ) , whose receptor is a tyrosine-specific protein kinase , provides the initial stimulus .
C1519726
tyrosine phosphorylation
C0033681
tyrosine-specific