Na+-coupled neutral amino acid transporter 1 (amino acid transporter A1, N-system amino acid transporter 2, system A amino acid transporter 1, system N amino acid transporter 1, solute carrier family 38 member 1, SLC38A1, ATA1, NAT2, SAT1, SNAT1)
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Function
- Na+-dependent amino acid transporter
- mediates saturable, pH-sensitive & electrogenic cotransport of glutamine & Na+ ions with a stoichiometry of 1:1
- may also transport small zwitterionic & aliphatic amino acids with a lower affinity
- may supply glutamatergic & GABAergic neurons with glutamine which is required for the synthesis of the neurotransmitters glutamate & GABA
- inhibited by K+, choline ions & 2- methylamino-isobutyric acid (MeAIB) (putative)
- inhibited by Li+ & N-methyl-D-glucamine
Structure
- belongs to the amino acid/polyamine transporter 2 family
Compartment
- cell membrane
- restricted to the somatodendritic compartment of neurons
- found in the cellular processes of neurons in the developing brain
Expression
- expressed in cerebral cortex by pyramidal & GABAergic neurons, astrocytes & other non-neuronal cells (at protein level)
- expressed in placenta, heart, lung, skeletal muscle, spleen, stomach & testis
- down-regulated by lipopolysaccharides in glial cells
- down-regulated upon hypoxia