Fig. 2

The AHR genomic pathway. Inactive AHR forms a protein complex with two HSP90, XAP2, p23, and SRC in the cytoplasm. Once engaged with exogenous or endogenous ligands, the AHR sheds XAP2 and Src and translocates to the nucleus. In the nucleus, the AHR binds with the ARNT and forms an active heterodimer, which modulates the expression of target genes by binding to xenobiotic responsive elements (XRE, 5ʹ-CGCGTG-3ʹ), thus recruiting coactivators including NCoA-2 and p/CIP and transactivating a variety of genres including the hydroxylases CYP1A1, CYP1B1, AHRR, and IDO