Sequence and chromosomal assignment of a human novel cDNA: similarity to gamma-aminobutyric acid transporter.
Gamma-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the mammalian brain. Although initially thought to be confined to the central nervous system, GABAergic activity has also been described in other tissues throughout the body. In the present study, we report the cloning and localization of human GABA transporter cDNA and document its expression in various human tissues. A human liver cDNA library was initially screened by a 32P-labeled murine brain GABA transporter 3 (GAT-3) cDNA probe, and full-length cDNA was cloned by employing Marathon-Ready human kidney cDNA. The human GABA transporter cDNA encoded a 569 amino acid hydrophobic protein with 12 transmembrane domains (TMs). Search of published sequences revealed high homology with rat GAT-2, murine GAT-3 cDNA, human solute carrier family 6 member 13 (SLC6A13), and a human peripheral betaine/GABA transporter. Northern blot analyses demonstrated that the human GABA transporter is expressed strongly in the kidney and to a lesser extent in the liver and brain. The sequence was well matched with human chromosome 12p13.3, suggesting the human GABA transporter contains 14 exons. The above findings confirm the existence of and further characterize a specific GABA transporter in human tissues.
Gong
Y
Y
Department of Medicine, University of Manitoba, Winnipeg, Canada.
Zhang
M
M
Cui
L
L
Minuk
G Y
GY
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002875:Chromosomes / Q000187:drug effects / Q000648:ultrastructure*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D050485:GABA Plasma Membrane Transport Proteins; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology; D015723:Gene Library; D006801:Humans; D008099:Liver / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D027361:Organic Anion Transporters; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014018:Tissue Distribution
D002352:Carrier Proteins; D018076:DNA, Complementary; D050485:GABA Plasma Membrane Transport Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D027361:Organic Anion Transporters; C493416:SLC6A11 protein, human; C493418:SLC6A13 protein, human