AHR
AHR (aryl hydrocarbon receptor, also known as bHLHe76) is a ligand-activated basic helix-loop-helix transcription factor that senses compounds from the environment, diet, microbiome and cellular metabolism. It regulates xenobiotic-metabolising enzymes and contributes to development, immunity and cancer biology. Browse Assay Genie's current range of AHR research reagents below, or read on for the biology behind the target.
AHR is a ligand-activated transcription factor that lets cells adapt to changing conditions by sensing compounds from the environment, diet, microbiome and cellular metabolism. Before ligand binding, the protein is sequestered in the cytoplasm. On binding a ligand it translocates into the nucleus, where it heterodimerises with ARNT and induces transcription by binding to xenobiotic response elements (XRE), also described as dioxin response elements (DRE) in target gene promoters.
Xenobiotics can act as AHR ligands. On xenobiotic binding, AHR activates the expression of multiple phase I and II xenobiotic-metabolising enzyme genes, such as CYP1A1, and mediates the biochemical and toxic effects of halogenated aromatic hydrocarbons. Natural ligands derived from plants, microbiota and endogenous metabolism are also potent AHR agonists, and tryptophan (Trp) derivatives form an important class of endogenous ligands. Through these inputs AHR regulates angiogenesis, haematopoiesis, drug and lipid metabolism, cell motility and immune modulation.
AHR has been linked to tumour immunity: indoles and kynurenic acid produced by Trp catabolism activate AHR, promoting AHR-driven cancer cell motility and suppressing adaptive immunity. It also regulates the circadian clock by inhibiting basal and circadian expression of PER1, repressing CLOCK-BMAL1-mediated activation of that gene. The AHR gene belongs to the basic helix-loop-helix and PAS domain-containing protein groups, and the mouse and rat orthologs are both named Ahr.
AHR drives expression of phase I and II xenobiotic-metabolising enzyme genes such as CYP1A1 and mediates the effects of halogenated aromatic hydrocarbons.
Trp-derived indoles and kynurenic acid activate AHR, promoting cancer cell motility and suppressing adaptive immunity.
AHR senses environmental, dietary and microbial signals and has important roles in development, immunity and immune modulation.
AHR inhibits basal and circadian PER1 expression by repressing CLOCK-BMAL1-mediated transcriptional activation.
AHR is a ligand-activated transcription factor. After ligand binding it moves from the cytoplasm to the nucleus, pairs with ARNT and binds xenobiotic response elements to switch on target genes, including xenobiotic-metabolising enzymes such as CYP1A1. It also influences angiogenesis, haematopoiesis, lipid metabolism and immune modulation.
The HGNC-approved name is aryl hydrocarbon receptor, and the symbol is AHR. The alias bHLHe76 reflects its membership of the basic helix-loop-helix family. HGNC also places it in the PAS domain-containing group. No previous names are recorded for the gene.
Orthologs exist in mouse and rat, both named Ahr. AHR mediates the toxic effects of halogenated aromatic hydrocarbons and acts as a negative regulator of anti-tumour immunity when activated by Trp-derived indoles and kynurenic acid. Check the datasheet of any product for its validated reactivity.
Related aryl hydrocarbon receptor pathway targets with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P35869; product specifications from Assay Genie datasheets.