SLC18A1
Function
Isoform 1
Electrogenic antiporter that exchanges one cationic monoamine with two intravesicular protons across the membrane of secretory and synaptic vesicles. Uses the electrochemical proton gradient established by the V-type proton-pump ATPase to accumulate high concentrations of monoamines inside the vesicles prior to their release via exocytosis. Transports catecholamines and indolamines with higher affinity for serotonin (PubMed:16326835, PubMed:23337945, PubMed:8643547). Regulates the transvesicular monoaminergic gradient that determines the quantal size. Mediates presynaptic monoaminergic vesicle transport in the amygdala and prefrontal brain regions related with emotion processing in response to environmental stimuli (PubMed:23337945).
Isoform 2
Unable to uptake serotonin.
Sequence Similarities
Belongs to the major facilitator superfamily. Vesicular transporter family.
Tissue Specificity
Expressed primarily in neuroendocrine tissues. Highly expressed in chromaffin cells of the adrenal medulla (at protein level). Detected in peripheral sympathetic ganglia (at protein level). Found in some paracrine cells in stomach and duodenum (at protein level) (PubMed:8643547). Expressed in substantia nigra (PubMed:23337945).
Isoform 1
Expressed in gastrointestinal tract.
Isoform 2
Expressed in gastrointestinal tract.
Cellular localization
- Cytoplasmic vesicle
- Secretory vesicle membrane
- Multi-pass membrane protein
- Cytoplasmic vesicle
- Secretory vesicle
- Synaptic vesicle membrane
- Multi-pass membrane protein
- Isoform 1
- Cytoplasmic vesicle
- Secretory vesicle membrane
- Multi-pass membrane protein
- Isoform 2
- Endoplasmic reticulum membrane
- Multi-pass membrane protein
Alternative names
VAT1, VMAT1, SLC18A1, Chromaffin granule amine transporter, Solute carrier family 18 member 1, Vesicular amine transporter 1