retinoidXreseptori

Retinoid X receptors, often abbreviated as RXRs, are a class of nuclear receptors that play a crucial role in gene regulation. They are members of the steroid hormone receptor superfamily. RXRs are unique in that they can form heterodimers with a variety of other nuclear receptors, including retinoid acid receptors (RARs), vitamin D receptors (VDRs), thyroid hormone receptors (TRs), and peroxisome proliferator-activated receptors (PPARs). These heterodimers bind to specific DNA sequences called response elements, which then modulate the transcription of target genes.

RXRs themselves can also form homodimers and bind to DNA. The ligands for RXRs are not fully understood, but it is believed that 9-cis retinoic acid is a primary endogenous ligand. However, RXRs are known to be activated by a diverse range of molecules, including fatty acids and eicosanoids, when partnered with other nuclear receptors. This promiscuity in ligand binding contributes to their wide-ranging physiological functions.

The physiological roles of RXRs are extensive and impact numerous biological processes. They are involved in cellular differentiation, proliferation, metabolism, and apoptosis. Consequently, RXRs are implicated in development, homeostasis, and disease processes such as cancer, metabolic disorders, and inflammatory conditions. Due to their central role in regulating gene expression, RXRs are considered important therapeutic targets for a variety of diseases.