Epidermal growth factor receptor regulation and function.

The epidermal growth factor (EGF) receptor is a transmembrane, cell-surface glycoprotein that mediates the mitogenic action of a family of ligands, including EGF and transforming growth factor alpha (TGF alpha). Perturbation of this signal transduction pathway by exposure to excess ligand, by overproduction of the normal EGF receptor, or by the presence of specific mutated forms of this receptor can result in dramatic alterations in cellular phenotype, including malignant transformation. Overstimulation of normal cells is avoided by precise control of the synthesis and degradation of EGF receptors. Regulation occurs at multiple levels, including transcriptional control. A number of DNA-binding proteins have now been identified which positively and negatively modulate EGF receptor gene transcription.