Molecular genetics of the thyrotropin receptor.

Thyroid-stimulating hormone (TSH) receptor has been cloned by a strategy exploiting its belonging to the superfamily of G-protein-coupled receptors. Comparison with the luteinizing hormone and follicle-stimulating hormone receptors shows that the glycoprotein hormone receptors constitute a subfamily of G-protein-coupled receptors with a large extracellular domain probably responsible for hormone binding. The recombinant human TSH receptor stably expressed in cell lines provides the tool to identify the targets of autoimmune reactions leading to Graves' disease and idiopathic myxedema.