Hormonal regulation of protein tyrosine kinase activity

Abstract

The ability to phosphorylate tyrosine residues in proteins is recognized to be an intrinsic property of receptors for insulin and epidermal growth factor (EGF) as well as several other growth factors. Recent elucidation of the amino acid sequences of the human insulin receptor and the human EGF receptor by recombinant DNA techniques has demonstrated significant homology with the intracellular and extracellular domains. This information, and results from the recent construction of a chimeric receptor molecule from the cloned human EGF receptor and insulin receptor cDNAs, are providing clues to the molecular mechanisms involved in the regulation of protein tyrosine kinase activity. That may turn out to have significance for therapy of certain cancers. In this review J. Ramachandran and Axel Ullrich discuss the structural and functional relationships of both the EGF and the insulin receptors.