Serotonin transporter whose primary function in the central nervous system involves the regulation of serotonergic signaling via transport of serotonin molecules from the synaptic cleft back into the pre-synaptic terminal for re-utilization. Plays a key role in mediating regulation of the availability of serotonin to other receptors of serotonergic systems. Terminates the action of serotonin and recycles it in a sodium-dependent manner. Monomer or homooligomer (By similarity). Interacts with TGFB1I1 (PubMed:16803896). Interacts with SEC23A, SEC24C and PATJ. Interacts with NOS1; the interaction may diminish the cell surface localization of SERT in the brain and, correspondingly, reduce serotonin reuptake. Interacts with filamentous actin and STX1A (By similarity). Interacts (via C-terminus) with SCAMP2; the interaction is direct and retains transporter molecules intracellularly (PubMed:16870614). Interacts with ITGAV:ITGB3 (By similarity). Could be part of recycling endosomes (PubMed:16870614). Density of transporter molecules on the plasma membrane is itself regulated by STX1A (By similarity). Density of transporter molecules on the plasma membrane is also regulated by serotonin (PubMed:17506858). Density of transporter molecules seems to be modulated by ITGAV:ITGB3 (By similarity). Expressed in platelets (at protein level). Phosphorylation at Thr-276 increases 5-HT uptake and is required for cGMP-mediated SERT regulation. A polymorphism in the promoter region (5-HTT gene-linked polymorphic region, 5-HTTLPR) is located approximately 1 kb upstream of the transcription initiation site and is composed of 16 repeat elements. The polymorphism consists of a 44-bp insertion or deletion involving repeat elements 6 to 8. The short allele is associated with lower transcriptional efficiency of the promoter compared with the long allele. Over half of the Caucasian population has a short allele. Individuals with one or two copies of the short allele exhibit more depressive symptoms, diagnosable depression and suicidality in relation to stressful life events than individuals homozygous for the long allele. The 5-HTTLPR polymorphism may influence susceptibility to anxiety [MIM:607834]. The polymorphism Val-425 seems to be linked to a susceptibility to obsessive-compulsive disorder (OCD) [MIM:164230]. Genetic variations in SLC6A4 determine the genetic susceptibility to alcoholism [MIM:103780]. 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. SLC6A4 subfamily. Was reported to interact with VIM, however the paper was retracted as some results and conclusions are not reliable. Was reported to interact with RAB4 and to be induced by serotonin, however the paper was retracted as some results and conclusions are not reliable. Serotonin transporter entry Love, love, love... -Issue 123 of November 2010