Thyroid hormone receptors bind to DNA as a heterodimer with

Thyroid hormone receptors most commonly bind to DNA as a heterodimer with Retinoid X receptor (RXR). Mechanism of action of Thyroid Receptors: Thyroid hormone acts by binding to a specific Nuclear Thyroid Receptor (TR) Nuclear Thyroid Receptor (TR) in-turn forms a heterodimer with Retinoid X receptor (RXR) another nuclear receptor Thyroid receptors function primarily by Heterodimerization with Retinoid X receptor (RXR) The TR/RXR Heterodimer then binds to DNA at specific sequences called Thyroid Hormone Response Elements Note that: Thyroid receptors (TR) may bind to DNA as monomers, homodimers, and heterodimers, but TR binding to DNA is greatly enhanced in response to thyroid hormones when the receptor is in the form of this heterodimer. Retinoid X receptor (RXR) stays silent and does not bind its natural liagands when it is complexed with Thyroid Receptors (The TR/RXR heterodimer doesnot bind to 9-cis retinoic acid, the usual ligand for RXR) Ref: Ganong 24th edition pgno: 348