[Cloning and analyzing of members of excitatory amino acid transporter family from neonatal mouse brain].

Excitatory amino acid transporter family (EAAT) contains several structure-related membrane proteins. They are essential for the removal of glutamate released from pre-synaptic terminal to terminate its action of synaptic transduction and maintaining the normal concentration of neurotransmitters in nerve system. To study these proteins in single animal model, we cloned several members of EAAT family, named mGLAST-1, mGLT-1, mEAAC1 and mASCT1, from a neonatal mouse brain cDNA library. The cDNA sequence of mASCT1 was firstly reported in mouse, it is composed of 3787 bp which has an open reading frame (ORF) encoding a protein of 532 amino acid residues. The mASCT1 protein was expressed in Xenopus oocyte and the function was characterized by 3H-Ser uptaking. The homology between human ASCT1 and mouse ASCT1 is 89.3%. The DNA sequence data shows the variance in length and composition exists in the sequence of 5'UTR and 3'UTR of mRNA in the family members of EAAT. This phenomenon may indicate a post-transcription regulation mechanism might exist in the gene expression of mouse EAAT family members.