What is the Aryl Hydrocarbon Receptor?
The Aryl Hydrocarbon Receptor (AhR) is a ligand-activated transcription factor protein that belongs to the basic helix-loop-helix (bHLH) Per-Arnt-Sim (PAS) family of transcription factors. It was originally characterized as the dioxin or polycyclic aromatic hydrocarbon receptor due to the role it plays in detoxifying a variety of environmental pollutants. That was until extensive research identified several groups of endogenous ligands and AhR’s function in biological development and homeostasis was discovered. This intracellular receptor is widely expressed in human tissues and has diverse physiological roles, including the regulation of immune system development, cell proliferation, and differentiation.