Zinc regulates the dopamine transporter in a membrane potential and chloride dependent manner

Neuropharmacology. 2009 Feb;56(2):531-40. doi: 10.1016/j.neuropharm.2008.10.009. Epub 2008 Oct 26.


The dopamine transporter (DAT), a membrane protein specifically expressed by dopaminergic neurons and mediating the action of psychostimulants and dopaminergic neurotoxins, is regulated by Zn(2+) which directly interacts with the protein. Herein, we report a host-cell-specific direction of the Zn(2+) effect on wild type DAT. Whereas low mumolar Zn(2+) decreased dopamine uptake by DAT expressing HEK293 cells, it stimulated uptake by DAT expressing SK-N-MC cells. Inhibition or stimulation was lost in a DAT construct without the binding site for Zn(2+). Also reverse transport was differentially affected by Zn(2+), dependent on whether the DAT was expressed in HEK293 or SK-N-MC cells. Pre-treatment of DAT expressing cells with phorbol-12-myristate-13-acetate, an activator of protein kinase C, attenuated the inhibitory effect of Zn(2+) on uptake in HEK293 cells and increased the stimulatory effect in SK-N-MC cells. Patch-clamp experiments under non-voltage-clamped conditions revealed a significantly higher membrane potential of HEK293 than SK-N-MC cells and a reduced membrane potential after phorbol ester treatment. Lowering chloride in the uptake buffer switched the stimulatory effect of Zn(2+) in SK-N-MC cells to an inhibitory, whereas high potassium depolarization of HEK293 cells switched the inhibitory effect of Zn(2+) to a stimulatory one. This study represents the first evidence that DAT regulation by Zn(2+) is profoundly modulated by the membrane potential and chloride.

MeSH terms

  • Amphetamine / pharmacology
  • Animals
  • Binding, Competitive / drug effects
  • Cell Line
  • Chlorides / metabolism*
  • Cocaine / analogs & derivatives
  • Cocaine / pharmacology
  • Dopamine Plasma Membrane Transport Proteins / genetics
  • Dopamine Plasma Membrane Transport Proteins / metabolism*
  • Dopamine Uptake Inhibitors / pharmacology
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / genetics
  • Histidine / genetics
  • Humans
  • Lysine / genetics
  • Male
  • Membrane Potentials / drug effects*
  • Membrane Potentials / genetics
  • Norepinephrine / metabolism
  • Norepinephrine Plasma Membrane Transport Proteins / genetics
  • Patch-Clamp Techniques
  • Protein Binding / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Tetradecanoylphorbol Acetate / analogs & derivatives
  • Tetradecanoylphorbol Acetate / pharmacology
  • Trace Elements / pharmacology*
  • Transfection
  • Zinc Sulfate / pharmacology*


  • Chlorides
  • Dopamine Plasma Membrane Transport Proteins
  • Dopamine Uptake Inhibitors
  • Norepinephrine Plasma Membrane Transport Proteins
  • Trace Elements
  • Histidine
  • (1R-(exo,exo))-3-(4-fluorophenyl)-8-methyl-8- azabicyclo(3.2.1)octane-2-carboxylic acid, methyl ester
  • 4-O-methyl-12-O-tetradecanoylphorbol 13-acetate
  • Zinc Sulfate
  • Amphetamine
  • Cocaine
  • Lysine
  • Tetradecanoylphorbol Acetate
  • Norepinephrine