Slc18a2
Function
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 a variety of catecholamines such as dopamine, adrenaline and noradrenaline, histamine, and indolamines such as serotonin (By similarity) (PubMed:10618388). Regulates the transvesicular monoaminergic gradient that determines the quantal size. Mediates somatodendritic dopamine release in hippocampal neurons, likely as part of a regulated secretory pathway that integrates retrograde synaptic signals (By similarity). Acts as a primary transporter for striatal dopamine loading ensuring impulse-dependent release of dopamine at the synaptic cleft (PubMed:9427251). Responsible for histamine and serotonin storage and subsequent corelease from mast cell granules (By similarity) (PubMed:10618388).
Sequence Similarities
Belongs to the major facilitator superfamily. Vesicular transporter family.
Tissue Specificity
Expressed in striata and substantia nigra.
Cellular localization
- Cytoplasmic vesicle
- Secretory vesicle
- Synaptic vesicle membrane
- Multi-pass membrane protein
- Cytoplasmic vesicle
- Secretory vesicle membrane
- Multi-pass membrane protein
- Cell projection
- Axon
- Cell projection
- Dendrite
- Sorted to large dense core granules in neuroendocrine cells, presumably at the level of the trans-Golgi network. In neurons it is predominantly detected in somatodendritic tubulovesicular membranes, a distinct population of secretory vesicles that undergo calcium-dependent exocytosis in axons and dendrites upon depolarization. Localized at synaptic vesicles in axons.
Alternative names
Vmat2, Slc18a2, Synaptic vesicular amine transporter, Monoamine transporter, Solute carrier family 18 member 2, Vesicular amine transporter 2, Vesicular monoamine transporter 2, VAT2