AZI23'UTR Is a New SLC6A3 Downregulator Associated with an Epistatic Protection Against Substance Use Disorders

Mol Neurobiol. 2018 Jul;55(7):5611-5622. doi: 10.1007/s12035-017-0781-2. Epub 2017 Oct 5.


Regulated activity of SLC6A3, which encodes the human dopamine transporter (DAT), contributes to diseases such as substance abuse disorders (SUDs); however, the exact transcription mechanism remains poorly understood. Here, we used a common genetic variant of the gene, intron 1 DNP1B sequence, as bait to screen and clone a new transcriptional activity, AZI23'UTR, for SLC6A3. AZI23'UTR is a 3' untranslated region (3'UTR) of the human 5-Azacytidine Induced 2 gene (AZI2) but appeared to be transcribed independently of AZI2. Found to be present in both human cell nuclei and dopamine neurons, this RNA was shown to downregulate promoter activity through a variant-dependent mechanism in vitro. Both reduced RNA density ratio of AZI23'UTR/AZI2 and increased DAT mRNA levels were found in ethanol-naive alcohol-preferring rats. Secondary analysis of dbGaP GWAS datasets (Genome-Wide Association Studies based on the database of Genotypes and Phenotypes) revealed significant interactions between regions upstream of AZI23'UTR and SLC6A3 in SUDs. Jointly, our data suggest that AZI23'UTR confers variant-dependent transcriptional regulation of SLC6A3, a potential risk factor for SUDs.

Keywords: Allele-dependent; Dopamine transporter; Kangaroo layout of genes; Ribonucleic repressor; Transcription factor; lncRNA.

MeSH terms

  • 3' Untranslated Regions / genetics*
  • Adaptor Proteins, Signal Transducing / genetics*
  • Adaptor Proteins, Signal Transducing / metabolism
  • Alleles
  • Cell Line
  • Cell Nucleus / metabolism
  • Dopamine Plasma Membrane Transport Proteins / genetics*
  • Dopamine Plasma Membrane Transport Proteins / metabolism
  • Dopaminergic Neurons / metabolism
  • Down-Regulation / genetics*
  • Epistasis, Genetic*
  • Humans
  • Promoter Regions, Genetic / genetics
  • Substance-Related Disorders / genetics*


  • 3' Untranslated Regions
  • AZI2 protein, human
  • Adaptor Proteins, Signal Transducing
  • Dopamine Plasma Membrane Transport Proteins
  • SLC6A3 protein, human