Inhibition of the omega-conotoxin-sensitive calcium current by distinct G proteins

Neuron. 1992 Apr;8(4):799-809. doi: 10.1016/0896-6273(92)90100-r.


Leu-enkephalin (Leu-Enk), norepinephrine (NE), somatostatin (SS), and bradykinin (BK) decrease the voltage-dependent calcium current in NG108-15 cells. Here we have investigated whether distinct G proteins, or a G protein common to all of the pathways, mediates this inhibition. We found that pertussis toxin (PTX) reduced all of these transmitter actions, except that of BK. To examine which of the PTX-sensitive pathways is transduced by GoA, we constructed an NG108-15 cell line that stably expresses a mutant, PTX-resistant alpha subunit of GoA. After treatment with PTX, the mutant GoA alpha rescued the Leu-Enk and NE pathways but not the SS pathway. At least three different G proteins can transduce receptor-mediated inhibition of calcium currents in nerve cells. The effects of these G proteins appear to converge on the omega-conotoxin GVIA-sensitive calcium current.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Bradykinin / pharmacology
  • Calcium Channels / physiology*
  • Cell Line
  • Cloning, Molecular
  • DNA / genetics
  • Enkephalin, Leucine / pharmacology
  • GTP-Binding Proteins / genetics
  • GTP-Binding Proteins / physiology*
  • Gene Expression
  • In Vitro Techniques
  • Ion Channel Gating / drug effects*
  • Membrane Potentials
  • Mutagenesis, Site-Directed
  • Norepinephrine / pharmacology
  • Peptides, Cyclic / pharmacology*
  • Pertussis Toxin
  • RNA, Messenger / genetics
  • Rats
  • Somatostatin / pharmacology
  • Virulence Factors, Bordetella / pharmacology
  • omega-Conotoxin GVIA


  • Calcium Channels
  • Peptides, Cyclic
  • RNA, Messenger
  • Virulence Factors, Bordetella
  • Somatostatin
  • Enkephalin, Leucine
  • DNA
  • omega-Conotoxin GVIA
  • Pertussis Toxin
  • GTP-Binding Proteins
  • Bradykinin
  • Norepinephrine