Serotonin transporter and Vesicular monoamine transporter 2 (SERT / VMAT2)

The serotonin transporter (SERT) and the vesicular serotonin release machinery, primarily the vesicular monoamine transporter 2 (VMAT2), are the two central proteins governing the lifecycle of serotonin (5-HT) in the nervous system. SERT, encoded by the SLC6A4 gene, is a plasma membrane transporter that terminates serotonergic signaling by resequestering 5-HT from the synaptic cleft into the presynaptic neuron (UniProt P31645). Once inside the cytoplasm, VMAT2 (encoded by SLC18A2) packages 5-HT into synaptic vesicles using a proton gradient, preparing it for subsequent exocytotic release (UniProt Q05940). This coordinated transport system is essential for maintaining serotonin homeostasis and is a major focal point for pharmacological intervention in psychiatry and neurology. Selective Serotonin Reuptake Inhibitors (SSRIs) target SERT to treat depression and anxiety by prolonging 5-HT activity in the synapse (StatPearls NBK532223). VMAT2 inhibitors, such as valbenazine, are utilized to manage hyperkinetic movement disorders like tardive dyskinesia by reducing the available pool of monoamines for release (StatPearls NBK546654). Additionally, certain psychoactive substances like MDMA act on both SERT and VMAT2 to induce a rapid, non-exocytotic release of serotonin, which can lead to profound psychological effects and risks such as serotonin syndrome (PubMed PMC4351501).

Other names

SLC6A4SLC18A25-HTT5-HT transporterVesicular monoamine transporter 2VMAT2SERTVesicular serotonin release machinery

Inhibition of the plasma membrane serotonin transporter (SERT) to block reuptake and inhibition of the vesicular monoamine transporter 2 (VMAT2) to deplete vesicular stores or induce reverse transport.