The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that controls the expression of a diverse set of genes. In the absence of ligand, AHR is retained in the cytoplasm. Upon ligand binding AHR translocates to the nucleus where it forms a heterodimer with aryl hydrocarbon receptor nuclear translocator (ARNT) (1). This receptor complex then recognizes AHR-response elements in target genes to regulate their transcription.
