Insulin receptor substrate
An important protein in insulin signalling, Insulin Receptor Substrate, IRS, has at least 4 different isoforms. For many years it was known as pp180 or pp185 as it was just seen as a 180-185 kDa band on a gel, and its function was unknown.
Once the insulin receptor has been activated, the β subunit of the insulin receptor phosphorylates the tyrosine residues on IRS. Once phosphorylated, the IRS becomes a docking protein for proteins that contain SH2 domains. The IRS protein contains phosphotyrosine binding (PTB) and PH PH_domain. IRS binds to the PI3K arm of insulin signalling, and the Grb2 arm, as well as other proteins containing SH2 domains including, Syp and Nck.
- ↑ S. Whelan, W. Dias, L Thiruneelakantapillai, M. Lane, G. Hart. (2010) 'Regulation of insulin receptor substrate 1 (IRS-1)/AKT kinase-mediated insulin signaling by O-Linked beta-N-acetylglucosamine in 3T3-L1 adipocytes', J Biol Chem, 285(8):5204-11.