Amino acid transporters and uses

Abstract

The present invention relates to novel mammalian amino acid transporter proteins and the genes that encode such proteins. The invention is directed toward the isolation, characterization and pharmacological use of a human amino acid transporter protein termed EAAT4 and genes encoding such a transporter. The invention specifically provides isolated complementary DNA copies of mRNA corresponding to this transporter gene. Also provided are recombinant expression constructs capable of expressing this amino acid transporter gene in cultures of transformed prokaryotic and eukaryotic cells, as well as such cultures of transformed cells that synthesize the human amino acid transporter protein encoded therein. The invention also provides methods for screening in vitro compounds having transport-modulating properties using preparations of transporter proteins from such cultures of cells transformed with recombinant expression constructs.

We claim:  
     
         1 . An antibody or fragment thereof that is immunologically reactive to a human excitatory amino acid transporter that is EAAT4.  
     
     
         2 . The antibody or fragment thereof according to  claim 1 , wherein the antibody is a monoclonal antibody.  
     
     
         3 . The antibody or fragment thereof according to  claim 1 , wherein a human excitatory amino acid transporter has an amino acid sequence identified by Seq. ID No. 2.  
     
     
         4 . A cell line which produces an antibody or fragment thereof that is immunologically reactive to a human excitatory amino acid transporter that is EAAT4.  
     
     
         5 . The cell line according to  claim 4 , wherein the antibody is a monoclonal antibody.  
     
     
         6 . The cell line according to  claim 4 , wherein a human excitatory amino acid transporter has an amino acid sequence identified by Seq. ID No. 2.  
     
     
         7 . An epitope of a human excitatory amino acid transporter that is EAAT4 wherein the epitope is immunologically reactive to the antibody or fragment thereof according to  claim 1 .  
     
     
         8 . The epitope according to  claim 7  wherein a human excitatory amino acid transporter has an amino acid sequence identified by Seq. ID No. 2.