GONADOTROPIN AND THYROTROPIN RECEPTORS

Gonadotrophin and thyrotrophin receptors belong to a subgroup of G-pro tein-coupled receptors. These receptors are characterized by a large e xtracellular domain that is responsible for the binding of the hormone . Soluble receptors, such as some luteinizing hormone receptors, arise from premessenger RNA alternative splicing, or, in the case of thyroi d-stimulating hormone (TSH) receptors, by the cleavage and shedding of the ectodomain. Follicle-stimulating hormone and TSH receptors are re stricted to the basolateral domain of their target cells. These recept ors are also present in endothelial cells of target organ vessels and are involved in hormone transcytosis. Various genetic abnormalities of these receptors have been described.