Aryl hydrocarbon receptor (AhR)

The Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor belonging to the bHLH/PAS superfamily. It plays a crucial role in sensing environmental chemicals (xenobiotics) and endogenous metabolites, regulating gene expression in response. Upon ligand binding, AhR translocates to the nucleus, dimerizes with ARNT, and binds to XRE/DRE sequences, modulating the transcription of target genes involved in xenobiotic metabolism, immune function, development, and other processes. Dysregulation of AhR is implicated in various diseases, including immunotoxicity, cancer, and developmental abnormalities.

Other names

AHRahrahRdioxin receptor

Ligand binding to AhR induces a conformational change, leading to dissociation from chaperone proteins (Hsp90, XAP2/AIP/ARA9, p23), translocation to the nucleus, dimerization with ARNT, binding to XRE/DRE sequences on DNA, and regulation of target gene transcription (e.g., CYP1A1, CYP1B1).