The insulin receptor is a member of the largely expanding family of plasma membrane receptors. In general, ligand binding induces receptor dimerization leading to activation and tyrosine phosphorylation of the cytoplasmic catalytic domain of the receptor. Activation of receptor tyrosine kinases leads to several cellular responses like proliferation, differentiation and survival. The insulin receptor family distinguishes from the other receptor tyrosine kinases in that it also mediates a metabolic response like stimulation of glucose uptake and glycogen synthesis. In this review the general principles of signaling by receptor tyrosine kinases are discussed. Besides, we point out the signaling pathways used by the insulin receptor itself.
Biomedical Reviews 1996; 5: 5-30.