EGF stimulates the processing and export of a secreted form of EGF receptor

Human A431 cells express a 100 kDa EGF-receptor homolog that contains only the external domain. The kinetics of its maturation and export are slow and comparable to those of the transmembrane receptor. Here we demonstrate that exogenously added EGF stimulates post-translational processing and export of this receptor through a pathway that is insensitive to inhibitors of protein synthesis. The results suggest that EGF may influence one or more of the rate determining steps that control receptor export from endoplasmic reticulum. This may constitute one of the pathways by which EGF regulates the expression of its receptor.