Affinity labeling of the protein kinase associated with the epidermal growth factor receptor in membrane vesicles from A431 cells.

摘要: Epidermal growth factor (EGF), a mitogenic polypeptide hormone, stimulates the phosphorylation of certain endogenous proteins in membrane preparations derived from A431 cells, human tumor cell line. Membrane vesicles prepared cells were reacted with 5'-p-fluorosulfonylbenzoyl adenosine (5'-p-FSO2BzAdo). Reaction 5'-p-FSO2BzAdo results time-dependent inhibition EGF-stimulable protein kinase activity which parallels an increase incorporation into 5'-p-sulfonylbenzoyl-[8-14C]adenosine moiety 5'-p-FSO2Bz[14C]Ado. The primary bands labeled have Mr = 170,000 and 150,000. Labeling these by 5'-p-FSO2Bz[14C]Ado is inhibited incubation adenyl-5'-yl imidodiphosphate, ATP analog. Inactivation N-ethylmaleimide or heating sharply decreased labeling Proteins molecular weights previously been identified as EGF receptor degradation product receptor. These experiments provide chemical evidence that are same protein.