RXRG

RXRG, short for retinoid X receptor gamma, is a member of the nuclear receptor superfamily and acts as a ligand-activated transcription factor. In cells, RXRG forms either homodimers or heterodimers with other nuclear receptors such as RARs (retinoic acid receptors), PPARs (peroxisome proliferator-activated receptors), LXRs (liver X receptors), and VDR (vitamin D receptor). Through these partnerships, RXRG helps regulate the expression of target genes in response to retinoids, especially 9-cis-retinoic acid, and coordinates processes such as development, metabolism, and differentiation.

The RXRG protein exhibits the typical nuclear receptor architecture, including an N-terminal activation domain, a central DNA-binding domain with two zinc finger motifs, a hinge region, and a C-terminal ligand-binding domain. This modular design allows RXRG to bind DNA at retinoid response elements and recruit coactivators or corepressors to modulate transcription.

RXRG is broadly expressed across tissues, with notable levels in adipose tissue, brain, and retina. Its activity influences metabolic pathways, lipid and glucose homeostasis, and developmental signaling. In the retina, RXRG participates in photoreceptor function and maturation, contributing to visual processes and cone pathways.

Clinical relevance is explored in studies of cancer and metabolic diseases, given RXRG’s role as a common partner for several nuclear receptors. Rexinoids, synthetic RXR agonists, target RXRG-containing dimers and are used in certain cancer therapies, such as cutaneous T-cell lymphoma, illustrating the therapeutic potential of RXRG signaling modulation.