Cloning and characterization of a glutamate transporter cDNA from human brain and pancreas.
L-Glutamate is the major excitatory neurotransmitter in the brain. Sufficient removal from the synaptic cleft after neurotransmission by the L-glutamate transport system is essential to prevent excitotoxicity and neurotoxicity. We isolated mRNA from human brain and pancreatic islet cells and screened for sequences of high homology to a previously characterized rat brain glutamate transporter. An isolated sequence (GLTR) shows a 87.5% and a 92.5% sequence similarity at the nucleotide and amino acid level, respectively, with a rat brain specific L-glutamate transporter but only a 65% homology to the recently cloned human glutamate/aspartate transporter. The human mRNA is differentially expressed in brain and to a lesser degree in pancreas and in fetal liver. The gene encoding for the newly identified cDNA is located on chromosome 5.
Manfras
B J
BJ
Department of Internal Medicine I, School of Medicine, University of Ulm, Germany.
Rudert
W A
WA
Trucco
M
M
Boehm
B O
BO
D000595:Amino Acid Sequence; D027322:Amino Acid Transport System X-AG; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism*; D006023:Glycoproteins / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010179:Pancreas / Q000378:metabolism*; D012313:RNA / Q000302:isolation & purification; D016415:Sequence Alignment
D027322:Amino Acid Transport System X-AG; D018076:DNA, Complementary; D006023:Glycoproteins; D012313:RNA