Sodium-dependent, high-affinity amino acid transporter that mediates the uptake of L-glutamate and also L-aspartate and D-aspartate. Functions as a symporter that transports one amino acid molecule together with two or three Na(+) ions and one proton, in parallel with the counter-transport of one K(+) ion . Acts primarily as an inhibitory glutamate-gated chloride channel being a major inhibitory presynaptic receptor at mammalian rod bipolar cell axon terminals. Glutamate binding gates a large Cl(-) conductance that mediates inhibition, affecting visual processing in the retina (By similarity).
Subcellular locations: Photoreceptor inner segment membrane, Synaptic cell membrane
Located in both cone and rod photoreceptor terminals and in axon terminals of rod bipolar cells.
Expressed primarily in retina. Detectable in liver, heart, muscle and brain.