Structure of the human dopamine transporter in complex with cocaine.

The dopamine transporter (DAT) is crucial for regulating dopamine signalling and is the prime mediator for the rewarding and addictive effects of cocaine. As part of the neurotransmitter sodium symporter family, DAT uses the Na gradient across cell membranes to transport dopamine against its chemical gradient. The transport mechanism involves both intra- and extracellular gates that control substrate access to a central site.

The dopamine transporter antiports potassium to increase the uptake of dopamine.

The dopamine transporter facilitates dopamine reuptake from the extracellular space to terminate neurotransmission. The transporter belongs to the neurotransmitter:sodium symporter family, which includes transporters for serotonin, norepinephrine, and GABA that utilize the Na gradient to drive the uptake of substrate. Decades ago, it was shown that the serotonin transporter also antiports K, but investigations of K-coupled transport in other neurotransmitter:sodium symporters have been inconclusive.