The insulin receptor (INSR) is a heterodimeric protein complex that has an intracellular subunit, which is disulfide-linked to a transmembrane segment. The insulin ligand binds to the INSR and initiates molecular signaling pathways that promote glucose uptake in cells and glycogen synthesis. Insulin binding to INSR induces phosphorylation of intra-cellular tyrosine kinase domains and recruitment of multiple SH2 and SH3 domain-containing intracellular proteins that serve as signaling intermediates for pleiotropic effects of insulin. Type 1 diabetes is an autoimmune condition of the endocrine pancreas that results in destruction of insulin secreting cells and a progressive loss in insulin-sensitive glucose uptake by cells.
