Upon binding to ligands such as dioxins, polycyclic aromatic hydrocarbons (PAHs), and endogenous tryptophan metabolites, AhR translocates to the nucleus where it dimerizes with the AhR nuclear translocator (ARNT). This heterodimer then binds to specific DNA sequences known as xenobiotic response elements (XREs) to regulate gene expression. Some of the well-known target genes include cytochrome P450 enzymes (CYP1A1, CYP1B1), which are involved in xenobiotic metabolism.
