Protein kinase C inhibition of the epidermal growth factor receptor tyrosine protein kinase activity is independent of the oligomeric state of the receptor.

摘要: Treatment of A431 human epidermoid carcinoma cells with 4-phorbol 12-myristate 13-acetate (PMA) causes an inhibition the high affinity binding epidermal growth factor (EGF) to cell surface receptors and EGF receptor tyrosine protein kinase activity. The hypothesis that PMA controls function by regulating oligomeric state was tested. Dimeric bound 125I-EGF were identified covalent cross-linking analysis using disuccinimidyl suberimidate. in presence 20 nM caused no significant change level labeled cross-linked monomeric dimeric species. Investigation vitro autophosphorylation monomers dimers 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide demonstrated treatment phosphorylation both receptors. We conclude activity is not associated regulation receptor.