High impact information on rxrbb

• We furthermore identified a retinoic acid response element (RARE) in the sonic hedgehog upstream region which can be bound by retinoic acid receptor (RAR) and retinoid X receptor (RXR) heterodimers in vitro and confers retinoic acid inducibility to the sonic hedgehog promoter in the HeLa cell system [1].
• These results suggest that Xenopus embryos possess a unique response pathway in which liganded RXR can control gene expression [2].
• In limited proteolysis analyses, both RXR and RAR in the heterodimer bound their respective ligands and underwent a conformational change in the presence of a retinoic acid-responsive element [3].
• Retinoid X receptor (RXR) within the RXR-retinoic acid receptor heterodimer binds its ligand and enhances retinoid-dependent gene expression [3].
• Two additional RXR subtypes (delta and epsilon) isolated from zebra fish cDNA libraries are described here; although both subtypes form DNA-binding heterodimers with RARs and TR, neither binds 9-cis RA, and both are transcriptionally inactive on RXR response elements [4].

Biological context of rxrbb

• Thus, the zebrafish genome contains duplicates of each RAR and RXR gene [5].
• All zebrafish RAR and RXR paralogs have overlapping and distinct areas of expression, as might be expected for duplicate genes in the process of diverging in function [5].

Analytical, diagnostic and therapeutic context of rxrbb

• Nevertheless, RXR-selective ligands activated only an RXR responsive reporter but not an RAR responsive reporter introduced by microinjection into the Xenopus embryo, consistent with our failure to detect conversion of an RXR-selective ligand to different derivatives in the embryo [2].

References