MOLECULAR-CLONING OF 2 GLUTAMATE TRANSPORTER SUBTYPES FROM MOUSE-BRAIN

The physiological action of glutamate is terminated by diffusional processes with its subsequent removal by high-affinity transport systems localized to glial and/or neuronal elements. Several cDNAs encoding glutamate transporters have been isolated from mammalian tissues. Here, we screened a cDNA library derived from mouse cerebellum and isolated the two glutamate transporters, termed MGLT1 and MEAAC1. The MGLT1 and MEAAC1 cDNAs encode proteins of 572 and 523 amino acids, respectively. MGLT1 has 93.9% amino acid sequence identity with the rat GLT1 and MEAAC1 has 89.3% identity with the rabbit EAAC1. MEAAC1 mRNA was expressed in brain, lung, kidney and skeletal muscle, whereas expression of MGLT1 was restricted to brain.