Ah receptor

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Ah receptor

A receptor that is detectable in many tissues and organs which binds various environmental pollutants, including polycyclic aromatic hydrocarbons, hetercyclic amines and polychlorinated aromatic compounds (e.g., dioxins, dibenzofurans and biphenyls), and mediates the well-known carcinogenic effects of these agents. Once bound via a helix-loop-helix motif and activated, the Ah receptor-ligand complex is transported to the nucleus where it binds to specific DNA sequences and variously turns genes on or off.
References in periodicals archive ?
Matsumoto et al., "Modulation of oestrogen receptor signalling by association with the activated dioxin receptor," Nature, vol.
* Many compounds that can dock in a cell's dioxin receptor may prove benign--and at times even therapeutic--new studies indicated (155: 156).
Most people, however, know it by its more ominous name: the dioxin receptor.
They argue that something is a dioxin only if it can turn on a cell's dioxin receptor, also called an aryl hydrocarbon (Ah) receptor.
Immortalized mouse mammary fibroblasts lacking dioxin receptor have impaired tumorigenicity in a subcutaneous mouse xenograft model.
Once that binding occurs, the dioxin receptor complex "sends out mixed signals that alter the expression of a multitude of different hormones or hormone receptors," she says.
Therefore, we measured dioxin-like activity in serum using the dioxin receptor (DR, or AhR)-driven Chemical-Activated LUciferase eXpression (DR-CALUX) in cultured H4IIE cells, as described in detail elsewhere (Koppen et al.
A study now appears to confirm what these scientists had come to suspect: The "dioxin receptor" harbors a split personality.
Only very small amounts of single ortho halobiphenyls can be found in commercial mixtures, and these mixtures are quite ineffective in eliciting effects associated with binding by the dioxin receptor.
Silbergeld, who is also an adjunct scientist to the Environmental Defense Fund, says there is no evidence that the dioxin receptor needs a specific accumulation of TCDD before it binds.