Sodium-dependent, high-affinity amino acid transporter that mediates the uptake of L-glutamate and also L-aspartate and D-aspartate (PubMed:7914198, PubMed:7521911, PubMed:8857541, PubMed:26690923, PubMed:21123949, PubMed:33658209). Can also transport L-cysteine (PubMed:21123949). 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 (PubMed:7521911, PubMed:8857541, PubMed:26690923, PubMed:33658209). Mediates Cl(-) flux that is not coupled to amino acid transport; this avoids the accumulation of negative charges due to aspartate and Na(+) symport (PubMed:8857541, PubMed:26690923). Plays an important role in L-glutamate and L-aspartate reabsorption in renal tubuli (PubMed:21123949). Plays a redundant role in the rapid removal of released glutamate from the synaptic cleft, which is essential for terminating the postsynaptic action of glutamate (By similarity). Contributes to glutathione biosynthesis and protection against oxidative stress via its role in L-glutamate and L-cysteine transport (By similarity). Negatively regulated by ARL6IP5 (By similarity). H(+)(out) + K(+)(in) + L-glutamate(out) + 3 Na(+)(out) = H(+)(in) + K(+)(out) + L-glutamate(in) + 3 Na(+)(in) H(+)(out) + K(+)(in) + L-aspartate(out) + 3 Na(+)(out) = H(+)(in) + K(+)(out) + L-aspartate(in) + 3 Na(+)(in) D-aspartate(out) + H(+)(out) + K(+)(in) + 3 Na(+)(out) = D-aspartate(in) + H(+)(in) + K(+)(out) + 3 Na(+)(in) Homotrimer (PubMed:33658209). Interacts with ARL6IP5. Interacts with RTN2 (via N-terminus); the interaction promotes cell surface expression of SLC1A1. Interacts with SORCS2; this interaction is important for normal expression at the cell membrane (By similarity). Expressed in all tissues tested including liver, muscle, testis, ovary, retinoblastoma cell line, neurons and brain (in which there was dense expression in substantia nigra, red nucleus, hippocampus and in cerebral cortical layers). Contains eight transmembrane regions plus two helical hairpins that dip into the membrane. These helical hairpin structures play an important role in the transport process. The first enters the membrane from the cytoplasmic side, the second one from the extracellular side. During the transport cycle, the regions involved in amino acid transport, and especially the helical hairpins, move vertically by about 15-18 Angstroms, alternating between exposure to the aqueous phase and reinsertion in the lipid bilayer. In contrast, the regions involved in trimerization do not move. Glycosylated. The disease is caused by variants affecting the gene represented in this entry. Disease susceptibility is associated with variants affecting the gene represented in this entry. A deletion at the chromosome 9p24.2 locus, including SLC1A1, has been identified in patients with psychotic disorders (PubMed:21982423). This 84 kb deletion is immediately upstream of the SLC1A1 gene in a regulatory region that contains the full native promoter sequence, extends through exon 1 of the SLC1A1 mRNA, co-segregates with disease in an extended 5-generation pedigree and increases disease risk more than 18-fold for family members (PubMed:23341099). Belongs to the dicarboxylate/amino acid:cation symporter (DAACS) (TC 2.A.23) family. SLC1A1 subfamily.