Thyroid hormone receptor

The thyroid hormone receptor is a type of nuclear receptor that is activated by binding thyroid hormone.

Function
Amongst the most important functions of thyroid hormone receptors are regulation of metabolism and heart rate. In addition, they play critical roles in the development of organisms.

Isoforms
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)

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