Abstract
The aryl hydrocarbon receptor (AhR) is widely distributed in vertebrates and is known to be involved in metabolism of xenobiotics including man-made chemicals, most of which act as a ligand for the receptor, although no endogenous ligand has yet been known. Upon binding a ligand, the receptor is activated to translocate to the nuclei, and during the nuclear translocation process, it is dissociated from the 90 kDa heat shock protein (Hsp90) to form a heterodimer with Arnt (Ah receptor nuclear translocator). The heterodimer complex binds a DNA response element termed xenobiotic responsive element (XRE) localized upstream of the target genes of many drug-metabolizing enzymes including cytochrome P4501A1 and glutathione S-transferase to activate their transcription. Recent cDNA cloning has revealed that the AhR, like Arnt, possesses characteristic structural motifs of basic helix-loop-helix and PAS domains responsible for DNA recognition, heterodimerization, and ligand binding, and functions as a novel receptor-type transcription factor.
Original language | English |
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Pages (from-to) | 1075-1079 |
Number of pages | 5 |
Journal | Journal of biochemistry |
Volume | 122 |
Issue number | 6 |
DOIs | |
Publication status | Published - 1997 Dec |
Externally published | Yes |
Keywords
- Carcinogenesis
- PAS domain
- Transcription factor
- Xenobiotics
- bHLH domain
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology