[The TSH receptor gene and the pathogenesis of Graves' disease].

The molecular cloning of the thyrotropin (TSH) receptor cDNA has led to advances in understanding the structure and function of the molecule and the pathogenesis of autoimmune thyroid disease. The recombinant TSH receptors expressed on mammalian cells are now available for TSAb and TBIAb assays. TBI assay in this system is much more sensitive than the conventional method. The binding sites for TSH and TSAb/TBIAb have been studied with epitope library, synthetic peptides, anti-peptide sera and mutagenesis. Some of these data, however, are confusing and undefined. The binding sites for TSH and TSAb/TBIAb are very likely to span the entire region of the extracellular domain of the TSH receptor with discontinuous contact points, and seem to be different from each other on N-terminal half, but similar on C-terminal half, of the extracellular domain of the receptor. However, the determination of the precise amino acids involved may be very difficult without monoclonal anti-TSH receptor antibodies.