Plasma membrane monoamine transporter

Plasma Membrane Monoamine Transporter (PMAT) is a protein that in humans is encoded by the SLC29A4 gene. PMAT is a member of the equilibrative nucleoside transporter (ENT) family, which also includes ENT1, ENT2, and ENT3. PMAT is unique among the ENTs in that it also transports monoamine neurotransmitters.

Function

PMAT functions as a neurotransmitter transporter, responsible for the uptake of monoamines, including serotonin, dopamine, and norepinephrine, into cells. This uptake is essential for the termination of neurotransmitter signals and for the recycling of these neurotransmitters. PMAT is expressed in various tissues, including the brain, heart, and kidney.

Structure

PMAT is a transmembrane protein, meaning it spans the cell membrane. It has 11 transmembrane domains and a large extracellular loop between the third and fourth transmembrane domains. The protein's N-terminus is located on the extracellular side of the membrane, while the C-terminus is on the intracellular side.

Clinical significance

Alterations in PMAT function or expression can have significant clinical implications. For example, reduced PMAT activity can lead to increased extracellular concentrations of monoamines, which can contribute to the development of depression and other neuropsychiatric disorders. Conversely, increased PMAT activity can lead to decreased extracellular monoamine concentrations, potentially contributing to conditions such as Parkinson's disease.

See also

• SLC29A4
• Monoamine neurotransmitter
• Neurotransmitter transporter
• Equilibrative nucleoside transporter