Insulin receptor substrate (IRS) transduction system: distinct and overlapping signaling potential

Insulin receptor substrate (IRS) proteins play a central role in maintaining basic cellular functions such as growth and metabolism. They act as an interface between multiple growth factor receptors possessing tyrosine kinase activity, such as the insulin receptor, and a complex network of intracellular signalling molecules containing Src homology 2 (SH2) domains. Four members (IRS-1, IRS-2, IRS-3, IRS-4) of this family have been identified which differ in their subcellular distribution and interaction with SH2 domain proteins. In addition, differential IRS tissue- and developmental-specific expression patterns may contribute to specificity in their signaling potential.