Cloning and characterization of the 3'-untranslated region of the human excitatory amino acid transporter 2 transcript.

The 3'-untranslated region (UTR) of the human excitatory amino acid transporter 2 (EAAT2) transcript was cloned and characterized. The full-length EAAT2 cDNA of 11 692 bp was found to contain 283 bp of 5' UTR, a 1725-bp open reading frame and an unusually long 3'-UTR of 9684 bp. The 3'-UTR of EAAT2 cDNA was well conserved among mammals, and human, macaque, rat and mouse cDNA had nearly identical 3' ends. The human EAAT2 transcripts were detected in brain, spinal cord, liver, adrenal gland, placenta and pancreas by northern hybridization, and many ESTs homologous to the human EAAT2 cDNA were found in numerous tissues. To investigate the role of human EAAT2 3'-UTR in gene expression, we constructed luciferase expression vectors containing 3'-UTR fragments spanning the entire length of the region. The individual fragments varied in their effects on reporter gene expression in human astrocytes by a factor of eight to ten suggesting a complex role of the 3'-UTR in post-transcriptional regulation of EAAT2 gene expression.