HTScan^® INS Receptor Kinase Assay Kit #7430

Insulin receptor (INSR) is a membrane receptor tyrosine kinase. The receptor molecule consists of a disulfide linked heterodimer. The α subunit is a 135 kDa extracellular fragment, and the β subunit is a 95 kDa fragment containing an extracellular domain, a single transmembrane domain, and an intracellular tyrosine kinase domain (1). Insulin ligand binding to this receptor results in receptor autophosphorylation and tyrosine kinase activation. INSR catalyzes the tyrosine phosphorylation of molecules such as IRS, Gab1, Shc, and Cbl, which further activate the downstream MAPK, PI3K, and TC10 pathways. This eventually leads to increases in glucose uptake and metabolism as well as cell growth (2,3). INSR has peptide substrate specificity similar to other receptor tyrosine kinase members, preferring acidic residues at the -1 to -4 positions and large hydrophobic amino acids at positions +1 and +3 (4).