The arylhydrocarbon receptor repressor (AhRR): structure, expression, and function.
The arylhydrocarbon receptor (AhR) pathway is known to be critical for cellular events, especially for those evoked by several environmental chemicals such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Whereas the function of the AhR in TCDD toxicity is well analyzed, the importance of the recently cloned AhRR in the TCDD-stimulated AhR signaling cascade is still unclear. In mammalian tissues, the AhRR gene seems to be ubiquitously expressed and its expression is altered by various AhR ligands. Basal and induced AhRR mRNA levels were found to be highly cell-, tissue- and species-specific. An inhibitory activity of the AhRR on AhR signaling was proposed from overexpression studies. However, there are not sufficient data showing such functional activity of the AhRR in vivo. This short overview summarizes the present knowledge about the AhRR and should stimulate research in the AhRR field to elucidate its physiological function and its toxicological importance in dioxin toxicity.
Haarmann-Stemmann
Thomas
T
Arbeitsgruppe Toxikologie, Institut für umweltmedizinische Forschung (IUF) an der Heinrich-Heine-Universität Düsseldorf gGmbH, Auf'm Hennekamp 50, D-40225 Düsseldorf, Germany. haarmann@uni-dusseldorf.de
Abel
Josef
J
D000818:Animals; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D006801:Humans; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology; D011110:Polymorphism, Genetic / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018336:Receptors, Aryl Hydrocarbon / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D012097:Repressor Proteins / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects
D000072317:Polychlorinated Dibenzodioxins; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; D012097:Repressor Proteins