Modulation of Epidermal Growth Factor Receptors on 3T3 Cells by Platelet-Derived Growth Factor

Abstract
Platelet-derived growth factor does not compete with epidermal growth factor (EGF) for binding to EGF receptors on the murine 3T3 cell surface, but it modulates EGF receptors in two ways: (i) it induces a transient down regulation of EGF receptors and (ii) it inhibits EGF-induced down regulation of EGF receptors. These data suggest a common cellular internalization mechanism for the receptors for both hormones.