Biosynthesis of the epidermal growth factor receptor in cultured human cells

Endocrinology. 1985 Feb;116(2):528-35. doi: 10.1210/endo-116-2-528.


A 160,000 mol wt precursor of the epidermal growth factor (EGF) receptor has been identified in human A-431 carcinoma cells and skin fibroblasts. The presence of one discrete precursor band indicates the presence of a slow processing step. We have determined that this slow processing step involves the conversion of high mannose N-linked oligosaccharides on the receptor precursor to primarily complex oligosaccharides on the mature form of the receptor. This is shown by 1) the presence of fucose, a characteristic terminal sugar of complex oligosaccharides, in only the mature receptor and by 2) the susceptibility of the precursor to digestion with endoglycosidase H, which cleaves high mannose N-linked oligosaccharides, but not complex oligosaccharides from glycoproteins. The precursor to mature receptor transition half-time is 1.7 h in A-431 cells. This long transition half-time causes an accumulation of approximately 7.2 X 10(5) precursor molecules per cell (approximately 12% of the total population of EGF receptors). The net quantity of mature EGF receptors, but not of receptor precursors, is reduced when EGF is added to the culture medium of A-431 cells. The presence of EGF in the growth medium also decreases electrophoretic migration (as a result of increased phosphate incorporation) of the mature receptor, but not that of the precursor. The EGF-insensitive state of the precursor is most likely due to its intracellular location.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Carcinoma / metabolism
  • Cells, Cultured
  • Electrophoresis, Polyacrylamide Gel
  • Epidermal Growth Factor / pharmacology
  • ErbB Receptors
  • Fibroblasts / metabolism
  • Humans
  • In Vitro Techniques
  • Kinetics
  • Molecular Weight
  • Protein Precursors / analysis
  • Receptors, Cell Surface / biosynthesis*
  • Skin / metabolism
  • Trypsin / metabolism


  • Protein Precursors
  • Receptors, Cell Surface
  • Epidermal Growth Factor
  • ErbB Receptors
  • Trypsin