Insulin-like growth factor-I receptor signal transduction: at the interface between physiology and cell biology

The insulin-like growth factor-I receptor (IGF-IR) mediates the biological actions of IGF-I and IGF-II. The IGFs play a critical role in promoting dev elopment, stimulating growth and organogenesis via mitogenic, antiapoptotic and chemotactic activity. Recent research has focused on the events that o ccur intracellularly upon receptor activation. Several pathways have been s hown to be important. The insulin-receptor substrate (IRS), SHC, GRB2, CRKI I and CRKL adaptor proteins have all been implicated in transmitting signal s to the nucleus of the cell. This review outlines some of the signalling p athways believed to be important in converting IGF-IR activation into chang es in cell behavior and metabolism. (C) 1998 Published by Elsevier Science inc. All rights reserved.