Phospho-IR/IGF1R (Tyr1158) Polyclonal Antibody, Alexa Fluor™ 488, Invitrogen™

Insulin and Insulin-like Growth Factor receptors are transmembrane tyrosine kinase receptors that play critical roles in development, cell growth and metabolism. Insulin/Insulin-like growth factor-1 binding to the extracellular domain of IR and IGFR leads to autophosphorylation of the receptor and activation of the intrinsic tyrosine kinase activity, which allows appropriate substrates to be phosphorylated. Phosphorylation sites that are unique to each receptor presumably play a key role in these signaling differences. The catalytic loops within the tyrosine kinase domains contain a three tyrosine motif corresponding to Tyr1158, 1162 and 1163 (for the IR) and Tyr1131, 1135 and 1136 (for the IGF1R). Autophosphorylation of the tyrosine sites within the activation loop proceeds in a processive manner initiating at the second tyrosine (1162 or 1135), followed by phosphorylation at tyrosines 1158 (IGF-1R tyrosine 1131), 1163 (IGF-1R tyrosine 1136), resulting in the full activation of IR and IGF1R.