Biosynthesis of the epidermal growth factor receptor in human epidermoid carcinoma-derived A431 cells.
Cell-Line, Electrophoresis-Polyacrylamide-Gel, Human, Molecular-Weight, Peptide-Fragments: an, Receptors-Endogenous-Substances: bi, SUPPORT-U-S-GOVT-P-H-S, Trypsin: me
J Biol Chem 1984 Jun 25;259(12):7902-8
Using human-specific antibody reagents, we have examined the biosynthesis of the epidermal growth factor receptor in human epidermoid carcinoma-derived A431 cells. Four Mr species (Mr = 70,000, 95,000, 135,000, and 145,000) are detected when cells are subjected to a brief pulse of L-[35S]methionine; an Mr = 165,000 species is detected after 45-60 min of exposure of cells to radiolabel. In pulse-chase experiments, the four lower Mr species appear to bear a precursor relation to the Mr = 165,000 protein. The molecule acquires N-linked oligosaccharide cotranslationally, and two of the species (Mr = 95,000 and 145,000) are susceptible to digestion with endo-beta-N-acetylglucosaminidase H. The Mr = 145,000 and Mr = 165,000 proteins, which become labeled with 125I-epidermal growth factor after treatment of intact cells with a bifunctional cross-linking reagent, are phosphorylated at serine and threonine on identical tryptic peptides.
Biosynthesis of the epidermal growth factor receptor in human epidermoid carcinoma-derived A431 cells. J Biol Chem 1984 Jun 25;259(12):7902-8