RAR/RXR

The nuclear retinoic acid receptors (RARs) are transcriptional transregulators, which control the expression of specific gene subsets subsequently to ligand binding and to strictly controlled phosphorylation processes. RARs consist of three subtypes, α (NR1B1), β (NR1B2) and γ (NR1B3), encoded by separate genes. RARs function as ligand-dependent transcriptional regulators, heterodimerized with retinoid X receptors (RXRs), which also consist of three types, α NR2B1, β (NR2B2) and γ (NR2B3). RARs play critical roles in a variety of biological processes, including development, reproduction, immunity, organogenesis and homeostasis, as assessed by vitamin A-deficiency (VAD), pharmacological and genetic studies conducted in the mouse.

Retinoid X receptor (RXR) belongs to a family of ligand-activated transcription factors that regulate many aspects of metazoan life. A class of nuclear receptors requires RXR as heterodimerization partner for their function.