The Insulin Receptor (InsR) is a heterodimeric receptor tyrosine kinase with an extracellular alpha-chain, a transmembrane domain and an intracellular beta-chain. InsR is activated upon binding of the peptide hormone insulin, leading to autophosphorylation of tyrosine residues 1146, 1150, and 1151 in the activation loop of the beta-chain. Additional autophosphorylation sites such as tyrosine residues 960, 972, 1316, and 1322 regulate the assembly of signal transduction complexes.
