IRS1

IRS1, insulin receptor substrate 1, alias HIRS-1. IRS1 is encoded by the human IRS1 gene, which is located on chromosome 2 in the q36.3 region. IRS1 is a phosphorylated protein involved in insulin and other cytokine signaling with multiple tyrosine residues that can be phosphorylated by insulin receptor tyrosine kinases. Phosphorylated IRS1 is able to bind and activate downstream effectors such as PI3K, thus playing a key role as an intermediary molecule in the insulin signaling system.
IRS1 plays a central role in the maintenance of basic cellular functions, such as growth, survival, and material metabolism, and its family members differ in their tissue distribution, subcellular localization, developmental expression timings, binding to insulin, and interaction with SH2-containing proteins. Mutations in IRS1 have been associated with type II diabetes and susceptibility to insulin resistance.