Molecular cloning of the alpha-1 subunit of an omega-conotoxin-sensitive calcium channel.
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.
Dubel
S J
SJ
Biotechnology Laboratory, University of British Columbia, Vancouver, Canada.
Starr
T V
TV
Hell
J
J
Ahlijanian
M K
MK
Enyeart
J J
JJ
Catterall
W A
WA
Snutch
T P
TP
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000502:physiology; D015220:Calcium Channels / Q000235:genetics* / Q000276:immunology; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics; D010456:Peptides, Cyclic / Q000494:pharmacology; D011233:Precipitin Tests; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D014018:Tissue Distribution; D014158:Transcription, Genetic; D020960:omega-Conotoxins
D015220:Calcium Channels; D009419:Nerve Tissue Proteins; D010456:Peptides, Cyclic; D012333:RNA, Messenger; D020960:omega-Conotoxins; C053423:Conus magus toxin; D004247:DNA