Thyrotropin receptor
The thyrotropin receptor is a receptor that responds to thyroid-stimulating hormone and stimulates the production of thyroxine and triiodothyronine. The TSH receptor is a member of the G protein-coupled receptor superfamily of integral membrane proteins and is coupled to the Gs protein.
It is primarily found on the surface of the thyroid epithelial cells, but also found on adipose tissue and fibroblasts. The latter explains the reason of the myxedema finding during Graves disease.Function
Upon binding circulating TSH, a G-protein signal cascade activates adenylyl cyclase and intracellular levels of cAMP rise. cAMP activates all functional aspects of the thyroid cell, including iodine pumping; thyroglobulin synthesis, iodination, endocytosis, and proteolysis; thyroid peroxidase activity; and hormone release.
