A quantitative regional expression profile of EAAT2 known and novel splice variants reopens the question of aberrant EAAT2 splicing in disease

• Published in: Neurochemistry international 2007, Vol.50 (1), p.271-280
• Main Authors: Lauriat, Tara L., Richler, Esther, McInnes, L. Alison
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions; Alternative Splicing; Animals; Base Sequence; Biological and medical sciences; Blotting, Northern; Brain - metabolism; DNA Primers; EAAT2; Excitatory Amino Acid Transporter 2 - genetics; Excitatory Amino Acid Transporter 2 - metabolism; Fundamental and applied biological sciences. Psychology; Gene expression; GLT1; Humans; Male; Quantitative RT-PCR; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; Vertebrates: nervous system and sense organs
• ISSN: 0197-0186; 1872-9754
• DOI: 10.1016/j.neuint.2006.08.014

The glutamate transporter 1 (GLT1) in rodents, or EAAT2 in humans, is alternatively spliced in a complex manner including the use of multiple 5′ and 3′ untranslated regions and several coding variants. We used quantitative RT-PCR to profile these splice variants in human and rat brain. We also used RT-PCR and Northern blotting to demonstrate that a novel isoform of GLT1b has an ∼11 kb 3′ UTR extending through intron 9, exon 10 and approximately 5 kb into the 3′ untranslated region of GLT1. However, our most important finding concerns an aberrant transcript lacking exon 9, which contains a motif permitting translocation from the endoplasmic reticulum. This variant had previously been associated with amyotrophic lateral sclerosis until several groups reported high levels in normal brain tissue. In contrast, our data shows that this aberrant transcript is present at 0.1–0.2% of the major EAAT2 isoforms.