Mediates transport of gamma-aminobutyric acid (GABA) together with sodium and chloride and is responsible for the reuptake of GABA from the synapse (PubMed:15234345, PubMed:16150932, PubMed:8420981, PubMed:30270321). The translocation of GABA, however, may also occur in the reverse direction leading to the release of GABA (By similarity). The direction and magnitude of GABA transport is a consequence of the prevailing thermodynamic conditions, determined by membrane potential and the intracellular and extracellular concentrations of Na(+), Cl(-) and GABA (By similarity). Can also mediate sodium- and chloride-dependent transport of hypotaurine but to a much lower extent as compared to GABA (PubMed:30270321). 4-aminobutanoate(out) + chloride(out) + 2 Na(+)(out) = 4-aminobutanoate(in) + chloride(in) + 2 Na(+)(in) chloride(out) + hypotaurine(out) + 2 Na(+)(out) = chloride(in) + hypotaurine(in) + 2 Na(+)(in) Inhibited by N-[4,4-Diphenyl-3-butenyl]-nipecotic acid (SKF-89976-A), L-2,4-diamino-n-butyric acid, guvacine and nipecotic acid. Interacts (via PDZ domain-binding motif) with PALS1; interaction increases SLC6A1-mediated GABA uptake. Localized at the presynaptic terminals of interneurons. Brain. Expressed in the dentate gyrus of hippocampus, striatum and cerebellum (at protein level). This protein is the target of psychomotor stimulants such as amphetamines or cocaine. Belongs to the sodium:neurotransmitter symporter (SNF) (TC 2.A.22) family. SLC6A1 subfamily.