This entry represents the trans-membrane domain (TMD) found in insulin receptor proteins. The TMD of the insulin receptor is within the beta-subunit and contains 23 amino acids. Mutations in the TMD were shown to have effects on receptor biosynthetic processing and kinase activation. Substitution of the entire TMD of the insulin receptor (IR) resulted in constitutive kinase activation in vitro, while replacing the TMD with that of glycophorin A inhibited insulin action. Structural studies show that TMD contains a helix and a kink when it is purified in dodecylphosphocholine (DPC) micelles. The residues 942-948 preceding the TMD have a propensity to be a short helix and may interact with membrane [1].

1: Solution structure of the transmembrane domain of the insulin receptor in detergent micelles. Li Q, Wong YL, Kang C; Biochim Biophys Acta. 2014;1838:1313-1321. PMID:24440425