Dual function of the voltage-dependent Ca2+ channel alpha 2 delta subunit in current stimulation and subunit interaction

Neuron. 1996 Feb;16(2):431-40. doi: 10.1016/s0896-6273(00)80061-6.


Voltage-dependent Ca2+ channels are modulated by complex interactions with the alpha 2 delta subunit. In vitro translation was used to demonstrate a single transmembrane topology of the alpha 2 delta subunit in which all but the transmembrane sequence and 5 carboxy-terminal amino acids are extracellular. The glycosylated extra-cellular domain is required for current stimulation, as shown by coexpression of truncated alpha 2 delta subunits with alpha 1A and beta 4 subunits in Xenopus oocytes and deglycosylation with peptide-N-glycosidase F. However, coexpression of the transmembrane domain-containing delta subunit reduced the stimulatory effects of full-length alpha 2 delta subunits and substitution of a different transmembrane domain resulted in a loss of current stimulation. These results support a model whereby the alpha 2 delta transmembrane domain mediates subunit interactions and the glycosylated extracellular domain enhances current amplitude.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / chemistry
  • Calcium Channels / chemistry
  • Calcium Channels / physiology*
  • Electric Stimulation
  • Electrophysiology
  • Female
  • Glycosylation
  • Models, Molecular
  • Oocytes / metabolism
  • Peptide Fragments / chemistry
  • Peptide Fragments / metabolism
  • Peptide Mapping
  • Rats
  • Xenopus


  • Antibodies
  • Calcium Channels
  • Peptide Fragments