Vesicular monoamine transporter 1 (VMAT1)

Vesicular monoamine transporter 1 (VMAT1), encoded by the SLC18A1 gene, is an integral membrane protein that accumulates monoamines—including serotonin, dopamine, norepinephrine, and epinephrine—into secretory vesicles of neuroendocrine cells and some neurons. VMAT1 operates as an antiporter, coupling the import of one monoamine with the efflux of two protons, driven by the vesicular proton gradient. This function is essential for proper neurotransmission in monoaminergic systems, and genetic variants of SLC18A1 are implicated in neuropsychiatric disease susceptibility, though specific causal mutations have not been robustly linked to monogenic disease. Drugs such as reserpine and tetrabenazine inhibit VMAT1 function—mainly leading to monoamine depletion, and thereby are used or studied in contexts of psychiatric and neuroendocrine disorders. VMAT1 is primarily expressed in peripheral tissues (adrenal medulla, sympathetic ganglia, some neurons of the gastrointestinal tract) and localizes to large dense core vesicles where it regulates neurotransmitter availability for exocytosis. The transporter is a member of the Major Facilitator Superfamily and the Drug:H⁺ Antiporter-1 Family, sharing structural and functional similarities with related monoamine (VMAT2) and acetylcholine (VAChT) transporters.

Other names

Chromaffin granule amine transporterCGATSLC18A1Solute carrier family 18 member 1VAT1

Competitive and non-competitive inhibition of monoamine vesicular uptake, primarily via blocking or allosteric modulation of VMAT1 substrate binding (reserpine is competitive; TBZ, DTBZOH, and ketanserin have non-competitive effects; inhibitory activity is generally weaker than for VMAT2)