Aryl hydrocarbon receptor repressor (AHRR)

Aryl hydrocarbon receptor repressor (AHRR) is a transcription factor and repressor protein that regulates cellular responses to environmental chemicals, particularly dioxins. It functions by competing with the aryl hydrocarbon receptor (AHR) for binding to ARNT (aryl hydrocarbon receptor nuclear translocator), inhibiting the activation of AHR target genes and providing a negative feedback loop in AHR signaling. AHRR is ubiquitously expressed in adult tissues but is low in fetal tissues, can act as a tumor suppressor, and its gene encodes a protein with both bHLH and PAS domains. Variants and changes in expression of AHRR have been linked to cancer risk, inflammation, toxicological responses, and potentially endometriosis. There are currently no approved drugs that directly target AHRR, although xenobiotic chemicals such as dioxins interact with the pathway AHRR regulates[1][2][3][4][6].

Other names

AHRRAhR repressorAhRRbHLHe77Class E basic helix-loop-helix protein 77KIAA1234aryl hydrocarbon receptor repressoraryl hydrocarbon hydroxylase regulatordioxin receptor repressor

Competitive inhibition of ARNT binding to AHR (prevents formation of active AHR-ARNT heterodimer, suppresses gene transcription); Transcriptional repression via negative feedback in the AHR signaling pathway