AHR

aryl hydrocarbon receptor

2 disorders 2 no genetic record 7p21.1 gene with protein product

HGNC:348 Monarch NCBI Gene 196 ENSG00000106546 UniProt P35869 OMIM 600253

Aliases: bHLHe76.

Normal function · from ai-gene-review (P35869, commit 79fe13b38970) · AI-generated, not KB evidence

AHR encodes the aryl hydrocarbon receptor, a ligand-activated bHLH-PAS transcription factor that senses xenobiotic, dietary, microbiome-derived, and endogenous metabolites. In unstimulated cells AHR is mainly cytoplasmic in a chaperone-associated receptor complex; ligand binding promotes nuclear accumulation, heterodimerization with ARNT, binding to AHR/xenobiotic response elements, and regulation of RNA polymerase II target genes. AHR controls detoxification and xenobiotic-response programs such as CYP1A1 induction and also has context-dependent roles in immune regulation, intestinal epithelial responses, tumor immune escape, circadian cross-talk, development, and retinal biology.

Primary function. AHR is a ligand-activated intracellular receptor/transcription factor. Ligand binding to cytoplasmic AHR promotes nuclear accumulation, ARNT heterodimerization, binding to AHR response elements, and regulation of xenobiotic/endogenous-ligand response genes.

molecular function: nuclear receptor activity · directly involved in: regulation of transcription by RNA polymerase II; xenobiotic metabolic process; response to xenobiotic stimulus · locations: cytoplasm; nucleus · in complex: aryl hydrocarbon receptor complex

Activated AHR heterodimerizes with ARNT to form the nuclear DNA-binding transcription-factor complex. This heterodimeric state is required for efficient AHR response element binding and target-gene activation. Crystal structures of ligand-bound AHR:ARNT:DNA complexes show an unconventional assembly with intimate PAS-B to PAS-B association between AHR and ARNT, with the AHR PAS-B domain serving as the principal ligand-binding pocket.

molecular function: protein heterodimerization activity · directly involved in: positive regulation of transcription by RNA polymerase II · locations: nucleoplasm · in complex: nuclear aryl hydrocarbon receptor complex

Inactive AHR is maintained in a cytosolic chaperone-associated receptor complex. HSP90/p23/XAP2 interactions support ligand-binding conformation, cytoplasmic retention, and ligand-dependent nuclear import.

molecular function: Hsp90 protein binding · directly involved in: response to xenobiotic stimulus · locations: cytoplasm · in complex: cytosolic aryl hydrocarbon receptor complex

In the knowledge base · computed from kb/ at build time

Disorders

Relationship is the entry's genetic[].relationship_type. untyped means the entry has a genetic record for the gene but does not type it; its free-text association is shown instead.

Disorder	Relationship	Where the gene appears
AIP-related pituitary adenoma predisposition	no genetic record	mechanism: Altered ligand-dependent growth hormone secretion; Dysregulated AHR target-gene transcriptional response; Reduced AIP-AHR co-chaperone binding function
Alcohol-Associated Liver Disease	no genetic record	discussion: (unnamed)

Identity from HGNC (snapshot 2026-10-01). Page layers are described in the gene pages documentation.