Amine transporter (PubMed:10375632, PubMed:12606774). Terminates the action of dopamine by its high affinity sodium-dependent reuptake into presynaptic terminals (By similarity). Regulator of light-dependent retinal hyaloid vessel regression, downstream of OPN5 signaling (PubMed:30936473). Homooligomer; disulfide-linked (By similarity). Interacts with PRKCABP and TGFB1I1 (PubMed:12177201). Interacts (via N-terminus) with SYNGR3 (via N-terminus) (PubMed:19357284). Interacts with SLC18A2 (PubMed:19357284). Interacts with TOR1A (ATP-bound); TOR1A regulates SLC6A3 subcellular location. Interacts with alpha-synuclein/SNCA (By similarity). Interacts with SEPTIN4 (PubMed:17296554). Localizes to neurite tips in neuronal cells (By similarity). Colocalizes with SEPTIN4 at axon terminals, especially at the varicosities (PubMed:17296554). Found in the substantia nigra and ventral tegmental dopamine neurons, in fibers of the medial forebrain bundle ascending into the striatum, and within dense fiber networks and varicosities in the dorsal and ventral striatum (at protein level) (PubMed:19357284, PubMed:17296554). Lower expression in the cortex (at protein level) (PubMed:19357284). Absent from the corpus callosum (PubMed:19357284). Expressed throughout the retina at postnatal day 8 (PubMed:30936473). This protein is the target of psychomotor stimulants such as amphetamines and cocaine. Belongs to the sodium:neurotransmitter symporter (SNF) (TC 2.A.22) family. SLC6A3 subfamily.