Protein Domain : IPR002981

Type:  Family Name:  Sodium:neurotransmitter symporter, GABA, GAT-2
Description:  Neurotransmitter transport systems are integral to the release, re-uptake and recycling of neurotransmitters at synapses. High affinity transport proteins found in the plasma membrane of presynaptic nerve terminals and glial cells are responsible for the removal from the extracellular space of released-transmitters, thereby terminating their actions []. Plasma membrane neurotransmitter transporters fall into two structurally and mechanistically distinct families. The majority of the transporters constitute an extensive family of homologous proteins that derive energy from the co-transport of Na+and Cl-, in order to transport neurotransmitter molecules into the cell against their concentration gradient. The family has a common structure of 12 presumed transmembrane helices and includes carriers for gamma-aminobutyric acid (GABA), noradrenaline/adrenaline, dopamine, serotonin, proline, glycine, choline, betaine and taurine. They are structurally distinct from the second more-restricted family of plasma membrane transporters, which are responsible for excitatory amino acid transport. The latter couple glutamate and aspartate uptake to the cotransport of Na+and the counter-transport of K+, with no apparent dependence on Cl-[]. In addition, both of these transporter families are distinct from the vesicular neurotransmitter transporters [, ].Sequence analysis of the Na+/Cl-neurotransmitter superfamily reveals that it can be divided into four subfamilies, these being transporters for monoamines, the amino acids proline and glycine, GABA, and a group of orphan transporters [].GABA is the major inhibitory transmitter in the mammalian brain, and is widely distributed throughout the nervous system. Molecular cloningstudies have resulted in the cloning of three Na+and Cl--coupled GABA transporters (known as GAT-1, GAT-2, GAT-3) and a betaine/GABA transporter(BGT-1). Each transporter shows varying affinities for GABA, different substrate and blocker pharmacologies, and different tissue localisation [].GAT-2 protein expression has been studied with immunocytochemistry. High levels of expression were detected in: the leptomeninges, choroid plexus,and ependyma, with lower levels in the cortical parenchyma. GAT-2-positive neuronal elements included perikarya, dendrites and axon terminals.Non-neuronal elements expressing GAT-2 included cells forming the pia and arachnoid mater, astrocytic processes, ependymal cells and epithelial cellsof the choroid plexuses. This widespread cellular expression of GAT-2 suggests that it may have several functional roles in the overall regulationof GABA levels in the brain []. Short Name:  Na/ntran_symport_GABA_GAT2

0 Child Features

0 Contains

1 Cross References

Identifier
PR01196

0 Found In

4 GO Annotations

GO Term Gene Name
GO:0005332 IPR002981
GO:0006836 IPR002981
GO:0005887 IPR002981
GO:0016020 IPR002981

4 Ontology Annotations

GO Term Gene Name
GO:0005332 IPR002981
GO:0006836 IPR002981
GO:0005887 IPR002981
GO:0016020 IPR002981

1 Parent Features

DB identifier Type Name
IPR000175 Family Sodium:neurotransmitter symporter

0 Proteins

7 Publications

First Author Title Year Journal Volume Pages PubMed ID
            15336049
            8811182
            8103691
            7823024
            9779464
            8774941
            10379832