MOLECULAR-BIOLOGY OF THE AROMATIC HYDROCARBON (DIOXIN) RECEPTOR

The aromatic hydrocarbon (AH) (dioxin) receptor was discovered almost 20 years ago and achieved notoriety as the front-line site of action o f highly toxic environmental chemicals such as halogenated dioxins and polychlorinated biphenyls. Increasing evidence suggests that the AH r eceptor plays a key role in proliferation and differentiation of cells exposed to dioxins and, perhaps, to endogenous ligands. Recent clonin g of the AH receptor and its indispensable partner, the AH:receptor-nu clear-translocator protein, has opened new opportunities to determine how the AH receptor functions, how it evolved and what its multiple ro les might be in normal physiology as well as in toxicology. This revie w by Allan Okey, David Riddick and Patricia Harper aims to provide a b rief history of AH receptor research and gives a timely summary of wha t is known and what is not known about the structure and function of t his fascinating protein.