ARNT gene

The ARNT gene (ARNT stands for: Aryl Hydrocarbon Receptor Nuclear Translocator) is a protein-coding gene located on chromosome 1q21.3. The ARNT gene encodes the nuclear translocator protein of the aryl hydrocarbon receptor, which forms a complex with the ligand-bound aryl hydrocarbon receptor (AhR) required for receptor function. Three alternatively spliced variants encoding different isoforms have been described for this gene.

Required for the activity of the aryl hydrocarbon receptor. After ligand binding, AHR translocates to the nucleus where it heterodimerizes with ARNT and induces transcription by binding to xenobiotic response elements (XRE). The complex initiates transcription of genes involved in the regulation of a variety of biological processes, including angiogenesis, hematopoiesis, drug and lipid metabolism, cell motility and immunomodulation (probably). The heterodimer binds to the DNA core sequence 5'-TACGTG-3' within the hypoxia response element (HRE) of the promoters of target genes and functions as a transcriptional regulator of the adaptive response to hypoxia.

The encoded protein was also identified as a beta subunit of a heterodimeric transcription factor, hypoxia-inducible factor 1 (HIF1). A t(1;12)(q21;p13) translocation leading to a TEL-ARNT fusion protein is associated with acute myeloblastic leukemia.

1. Haidar R et al. (2021) The role of DNA-binding and ARNT dimerization on the nucleo-cytoplasmic translocation of the aryl hydrocarbon receptor. Sci Rep 11:18194.