D2 dopamine receptors interact directly with N-type calcium channels and regulate channel surface expression levels

Channels (Austin). 2008 Jul-Aug;2(4):269-77. doi: 10.4161/chan.2.4.6402. Epub 2008 Jul 9.


N-type channels are located on dendrites and at pre-synaptic nerve terminals where they play a fundamental role in neurotransmitter release. They are potently regulated by the activation of a number of different types of pertussis toxin (PTX)-sensitive G alpha(i/o) coupled receptors, which results in voltage-dependent inhibition of channel activity via G betagamma subunits. Using heterologous expression in HEK 293T cells, we show via whole cell patch clamp recordings that D2 receptors mediate both G betagamma (i.e., voltage-dependent) and voltage-independent inhibition of channel activity. Furthermore, using co-immunoprecipitation and pull down assays involving the intracellular regions of each protein, we show that D2 receptors and N-type channels form physical signaling complexes. Finally, we use confocal microscopy to demonstrate that D2 receptors regulate N-type channel trafficking to affect the number of calcium channels available at the plasma membrane. Taken together, these data provide evidence for multiple voltage-dependent and voltage-independent mechanisms by which D2 receptor subtypes influence N-type channel activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / chemistry*
  • Calcium Channels, N-Type / chemistry
  • Calcium Channels, N-Type / physiology*
  • Cell Line
  • Cell Membrane / metabolism*
  • Glutathione Transferase / metabolism
  • Humans
  • Microscopy, Confocal
  • Pertussis Toxin / chemistry
  • Protein Binding
  • Protein Structure, Tertiary
  • Rats
  • Receptors, Dopamine D2 / chemistry*
  • Receptors, Dopamine D2 / metabolism
  • Signal Transduction


  • Calcium Channels, N-Type
  • Receptors, Dopamine D2
  • Pertussis Toxin
  • Glutathione Transferase
  • Calcium