Molecular cloning of the alpha-1 subunit of an omega-conotoxin-sensitive calcium channel

Proc Natl Acad Sci U S A. 1992 Jun 1;89(11):5058-62. doi: 10.1073/pnas.89.11.5058.


Of the four major types of Ca channel described in vertebrate cells (designated T, L, N, and P), N-type Ca channels are unique in that they are found specifically in neurons, have been correlated with control of neurotransmitter release, and are blocked by omega-conotoxin, a neuropeptide toxin isolated from the marine snail Conus geographus. A set of overlapping cDNA clones were isolated and found to encode a Ca channel alpha-1 subunit, designated rbB-I. Polyclonal antiserum generated against a peptide from the rbB-I sequence selectively immunoprecipitates high-affinity 125I-labeled omega-conotoxin-binding sites from labeled rat forebrain membranes. PCR analysis shows that, like N-type Ca channels, expression of rbB-I is limited to the nervous system and neuronally derived cell lines. This brain Ca channel may mediate the omega-conotoxin-sensitive Ca influx required for neurotransmitter release at many synapses.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brain / physiology
  • Calcium Channels / genetics*
  • Calcium Channels / immunology
  • Cloning, Molecular
  • DNA / genetics
  • Gene Expression
  • Molecular Sequence Data
  • Nerve Tissue Proteins / genetics
  • Peptides, Cyclic / pharmacology
  • Precipitin Tests
  • RNA, Messenger / genetics
  • Rats
  • Tissue Distribution
  • Transcription, Genetic
  • omega-Conotoxins*


  • Calcium Channels
  • Nerve Tissue Proteins
  • Peptides, Cyclic
  • RNA, Messenger
  • omega-Conotoxins
  • Conus magus toxin
  • DNA

Associated data

  • GENBANK/M92905