Thyroid hormone receptor

The thyroid hormone receptor is a type of nuclear receptor that is activated by binding thyroid hormone. Among its most important functions are regulation of metabolism and heart rate. In addition, it plays a critical role in the development of organisms.

There are three forms of the thyroid hormone receptor designated alpha-1, beta-1 and beta-2 that are able to bind thyroid hormone. There are two TR-alpha receptor splice variants encoded by the gene and two TR-beta isoform splice variants encoded by the  gene:


 * TR-α1 (widely expressed and especially high expression in cardiac and skeletal muscles)
 * TR-α2 (homologous with viral oncogen c-erb-A, also widely expressed but unable to bind hormone)
 * TR-β1 (predominately expressed in brain, liver and kidney)
 * TR-β2 (expression primarily limited to the hypothalamus and pituitary)

Certain mutations in the thyroid hormone receptor are associated with thyroid hormone resistance.