Biosynthesis of the epidermal growth factor receptor in cultured human cells
| Autor: | Graham Carpenter, A. M. Soderquist, Christa M. Stoscheck |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Receptors
Cell Surface In Vitro Techniques Fucose chemistry.chemical_compound Endoglycosidase H Endocrinology Biosynthesis Epidermal growth factor medicine Humans Trypsin Epidermal growth factor receptor Protein Precursors Receptor Cells Cultured Skin Growth medium biology Epidermal Growth Factor Carcinoma Fibroblasts ErbB Receptors Molecular Weight Kinetics chemistry Biochemistry biology.protein Electrophoresis Polyacrylamide Gel medicine.drug |
| Zdroj: | Endocrinology. 116(2) |
| ISSN: | 0013-7227 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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