Retinoid X receptor, beta Adenovirus (Ad-RXRb)

Retinoids are metabolites of vitamin A (retinol) that represent an important group of signaling molecules during vertebrate development and tissue differentiation. Retinoic acid receptors (RARs) include RAR-alpha, RAR-beta and RAR-gamma, each of which has a high affinity for all transretinoic acids. Members of the retinoid X receptor (RXR) family, RXR-alpha, RXR-beta1, RXR-beta2 and RXR-gamma, are activated by 9-cis-retinoic acid, a stereo- and photoisomer of all transretinoic acids that is expressed in vivo in both liver and kidney and may represent a widely used hormone. The RAR-related orphan nuclear receptors (ROR) bind DNA as monomers and include ROR-alpha, ROR-beta and ROR-gamma. DAX-1 binds to retinoic acid response elements to mediate transcription. FXR (activated by farnesol and related metabolites) binds RXR to form a heterodimer, which subsequently binds IR-1 elements.