Dopamine transporter
| Dopamine transporter | ||
|---|---|---|
| Mass / length primary structure | 620 amino acids | |
| Identifier | ||
| Gene name (s) | SLC6A3 | |
| External IDs | ||
| Occurrence | ||
| Parent taxon | Bilateria | |
The dopamine transporter ( DAT ) is a protein found in the cell membrane that enables the hormone and neurotransmitter dopamine to be transported into the cell . As a transport protein , which belongs to the family of sodium neurotransmitter symporters , it removes released dopamine from the synaptic gap . This stops the effects of dopamine.
An inhibition of the dopamine transporter or even a reversal of their transport direction is partly responsible for the effect of some psychostimulants such as methylphenidate , cocaine and methamphetamine . Some antidepressants act on the dopamine transporter, e.g. B. Bupropion .
The transport equation is:
- Dopamine (outside) + Na + (outside) dopamine (inside) + Na + (inside)
The cell-inward transport of dopamine is driven as a secondary active process by the sodium-potassium-ATPase .
Occurrence
Dopamine transporters are found where neurons presynaptically release dopamine. This includes e.g. B. the substantia nigra and the area tegmentalis ventralis . But the DAT is also expressed in peripheral organs and in peripheral nerve cells.
genetics
The human dopamine transporter is formed by a as SLC6A3 designated gene on chromosome 5 in the gene locus encoding p15.3. The gene contains 15 different exons . Different polymorphisms in the gene are associated with some clinical pictures, e.g. B. Depression.
biochemistry
structure
The dopamine transporter is a transmembrane protein that, like other proteins from the sodium neurotransmitter symporter family , is assumed to have a structure consisting of twelve helices spanning the cell membrane . This structural feature could previously be detected with the help of crystal structure analysis for related bacterial transporters, such as lactose permease , the glycerol-3-phosphate transporter and the leucine transporter .
function
The dopamine transporter is responsible for the transport of dopamine from the extracellular space into the intracellular space. In the nervous system , the transporter takes over dopamine again from the synaptic gap to stop the dopamine effect.
Individual evidence
- ↑ TCDB : 2.A.22
- ↑ Abramson J, Smirnova I, Kasho V, Verner G, Kaback HR , Iwata S: Structure and mechanism of the lactose permease of Escherichia coli . In: Science . 301, No. 5633, August 2003, pp. 610-5. doi : 10.1126 / science.1088196 . PMID 12893935 .
- ↑ Huang Y, Lemieux MJ, Song J, Auer M, Wang DN: Structure and mechanism of the glycerol-3-phosphate transporter from Escherichia coli . In: Science . 301, No. 5633, August 2003, pp. 616-20. doi : 10.1126 / science.1087619 . PMID 12893936 .
- ↑ Zhou Z, Zhen J, Karpowich NK, et al. : LeuT-desipramine structure reveals how antidepressants block neurotransmitter reuptake . In: Science . 317, No. 5843, September 2007, pp. 1390-1393. doi : 10.1126 / science.1147614 . PMID 17690258 .