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Down‐modulation of EGF receptors in cells transformed by the src oncogene
Author(s) -
Wasilenko William J.,
Shawver Laura K.,
Weber Michael J.
Publication year - 1987
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041310318
Subject(s) - epidermal growth factor , receptor , proto oncogene tyrosine protein kinase src , microbiology and biotechnology , biology , cell surface receptor , oncogene , transforming growth factor , intracellular , cell culture , growth factor , growth factor receptor , cell , signal transduction , cell cycle , biochemistry , genetics
The effects of src oncogene expression on epidermal growth factor (EGF) receptors have been investigated in mouse 3T3 and rat‐1 fibroblasts. Transformation of both cell types with src resulted in marked reductions in cellular EGF receptor levels, as assayed by either 125 I‐EGF binding or immunoprecipitation of receptor protein from radiolabeled cell lysates. In contrast to cells transformed by other types of retroviral oncogenes, the loss of EGF receptors in the src ‐transformed cells did not appear to be due to secreted transforming growth factor‐α (TGF‐α), since such factors were undetectable in culture fluids from the src ‐transformed cells. By several criteria of transformation, an EGF‐receptorless cell line infected with src was shown to be transformed, suggesting that EGF receptors themselves are not obligatory to the src transformation process. We suggest that pp60 src down‐modulates EGF receptors by an intracellular mechanism and that the loss of the receptors is symptomatic of more general effects of pp60 src on the machinery of growth regulation.