Insulin receptor tyrosine kinase and insulin action

Abstract

Regulation of cellular metabolism and growth by insulin is the result of a series of events initiated by the interaction of the hormone with its cell surface receptors. The insulin receptor structure has been elucidated through a variety of techniques (Van Obberghen, 1984), and more recently, the aminoacid sequence of the human insulin receptor precursor was unravelled by recombinant DNA technology (Ullrich et al., 1985; Ebina et al., 1985). Despite this progress the molecular mechanism of insulin action is still not entirely comprehended regarding the events following receptor binding and leading to the ultimate cellular responses. However, over the years considerable evidence has been gathered indicating that reversible phosphorylation contributes to the mechanism of insulin action (Denton, 1986). Further, a promising discovery was made by the demonstration that the insulin receptor is an insulin-sensitive protein kinase (Kasuga et al., 1982; Van Obberghen and Kowalski, 1982; Petruzzelli et al., 1982).