Structure and Function of Insulin Receptors

  1. Ora M Rosen
  1. Program in Molecular Biology, Memorial Sloan-Kettering Cancer Center and Cornell University Graduate School of Medical Sciences New York, New York
  1. Address correspondence and reprint requests to Ora M. Rosen, 1275 York Avenue, Box 97, New York, NY 10021.

Abstract

The actions of insulin are mediated by an integral plasma membrane protein, the insulin receptor. The processed receptor is a tetramer composed of two α-subunits that bind insulin and two β-subunits that traverse the plasma membrane and are, in their cytosolic domains, protein tyrosine kinases. The insulin proreceptor cDNA has been cloned and its complete amino acid sequence deduced. The availability of cDNA permitted an analysis of both the role of protein tyrosine kinase activity in insulin action and the autophosphorylation sites that regulate kinase activity. The human cDNA probe has also been used to identify a putative Drosophila insulin receptor. This work is reviewed, and approaches that may be used to identify physiological substrates for the receptor kinase are suggested.

  • Received June 20, 1989.
  • Revision received July 12, 1989.
  • Accepted July 12, 1989.
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