Regulation of epidermal growth factor receptor expression and activation: a brief review.

The epidermal growth factor receptor, a transmembrane protein tyrosine kinase, plays a crucial role in cellular signalling both in embryonic development and in adult tissues. By phosphorylation of substrate proteins on tyrosine, signals may be transmitted which result in gene expression, ion flux and mitogenesis to name but a few of the pleiotropic effects of receptor activation. The epidermal growth factor receptor is relatively well studied amongst an increasing family of tyrosine kinases and makes a good model system for studying structure-function relationships involved in signal transduction. Here, the structure-function relationships for cellular transformation by the EGF receptor proto-oncogene are reviewed as well as data pertaining to its overexpression in human tumors.