The thyrotropin receptor (or TSH receptor) is a receptor (and associated protein) that responds to
thyroid-stimulating hormone (also known as "thyrotropin") and stimulates the production of
thyroxine (T4) and
triiodothyronine (T3). 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. In addition, it has also been found to be expressed in the anterior pituitary gland, hypothalamus and kidneys. Its presence in the anterior pituitary gland may be involved in mediating the paracrine signaling feedback inhibition of thyrotropin along the hypothalamus-pituitary-thyroid axis.
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. TSHR is involved in regulating seasonal reproduction in vertebrates.
See also
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Graves' disease
Graves' disease (german: Morbus Basedow), also known as toxic diffuse goiter, is an autoimmune disease that affects the thyroid. It frequently results in and is the most common cause of hyperthyroidism. It also often results in an enlarged thyr ...
References
Further reading
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External links
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SSFA-GPHR: Sequence Structure Function Analysis of Glycoprotein Hormone ReceptorsGRIS: Glycoprotein-hormone Receptor Information System*
{{Neuropeptide receptors
G protein-coupled receptors
Thyroid