Thyroid Hormone Receptor

Thyroid hormone receptor is a member of the nuclear receptor superfamily that shuttles between the cytosol and nucleus. Thyroid hormone receptors are ligand-dependent transcription factors that mediate the biological activities of thyroid hormone (T3). Thyroid hormone receptors are encoded by two genes, one for TRα and another for TRβ, which encode the major isoforms of TR, including TRα1, TRα2, TRβ1, and TRβ2. The thyroid hormone receptors mediate the pleiotropic activities of the thyroid hormone (T3) in growth, development, and differentiation and in maintaining metabolic homeostasis.

Thyroid hormone receptors are zinc finger transcription factors in the erbA superfamily that bind DNA at specific response element sequences (thyroid hormone response elements, TREs) and activate gene expression in response to thyroid hormone (T3). Thyroid hormone receptors have been shown to bind DNA as monomers, homodimers, or heterodimers with another erbA superfamily member, the retinoid X receptor (RXR).