GABA transporter 1 transcriptional starting site exhibiting tissue specific difference

JIN Xiao Ping^*, Fang HUANG^*, Na YANG, Bu Feng LU, Jian FEI ^**, Li He GUO^**

Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China

GABA transporter 1(GAT1) takes important roles in multiple physiological processes through the uptake and release of GABA, but the regulation of GAT1 gene expression in different tissues is rarely known. To address the question, first, 5' Rapid amplification of cDNA end (RACE) was used to determine GAT1 transcriptional starting sites in neonatal mouse cerebral cortex and intestine, adult mouse brain and adult rat testis. The products of 5'RACE were confirmed by DNA sequencing. We found that the transcript of GAT1 in neonatal mouse cerebral cortex and adult mouse brain starts at the same site (inside of exon 1), while in mouse intestine, GAT1 starts transcription in intron 1, and in rat testis, the transcript of GAT1 has an additional untranslation exon to the 5' direction.

Key words:GABA transporter 1(GAT1), transcriptional starting site, 5' RACE, tissue specific difference, DNA sequencing.