Biochem/physiol Actions

Retinoid X receptor (RXR) serves as a promiscuous heterodimerization partner for many nuclear receptors through the identity box, a 40-amino acid subregion within the ligand binding domain (LBD). RXR partners include thyroid hormone receptors (TRs), retinoic acid receptors (RARs), peroxisome proliferator-activated receptor, several constitutive active orphan nuclear receptors (e.g. nuclear growth factor I-B), oxysterol receptors, and constitutive androstane receptors. RXRs also form homodimers to mediate the effects of 9-cis-retinoic acid (9-cRA). Depending on these protein-protein interactions, RXR-containing complexes have distinct ligand-dependent and constitutive functions. The LBD is functionally complex and mediates ligand binding, receptor homo- and heterodimerization, repression of transcription in the absence of ligand, and ligand-dependent activation of transcription. Hormone binding to the structurally conserved LBD of the RXR triggers a conformational change that principally affects the conserved C-terminal transactivation helix H12 involved in transcriptional activation. Coactivators directly recruited by liganded receptors include members of the steroid receptor coactivator/p160 family such as SRC-1, transcriptional intermediary factor 2/glucocorticoid receptor interacting protein 1, and RAC3/activator of thyroid and retinoic acid receptors/amplified in breast cancer 1.

Physical form

Clear and colorless frozen liquid solution

Preparation Note

Use a manual defrost freezer and avoid repeated freeze-thaw cycles. While working, please keep sample on ice.