Dubel S J, Starr T V, Hell J, Ahlijanian M K, Enyeart J J, Catterall W A, Snutch T P
Biotechnology Laboratory, University of British Columbia, Vancouver, Canada.
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.
在脊椎动物细胞中描述的四种主要类型的钙通道（分别命名为T、L、N和P）中，N型钙通道很独特，因为它们专门存在于神经元中，与神经递质释放的控制相关，并且被ω-芋螺毒素阻断，ω-芋螺毒素是一种从海洋蜗牛地纹芋螺中分离出的神经肽毒素。一组重叠的cDNA克隆被分离出来，发现它们编码一种钙通道α-1亚基，命名为rbB-I。针对rbB-I序列中的一个肽段产生的多克隆抗血清能从标记的大鼠前脑膜中选择性地免疫沉淀高亲和力的125I标记的ω-芋螺毒素结合位点。PCR分析表明，与N型钙通道一样，rbB-I的表达仅限于神经系统和神经源性细胞系。这种脑钙通道可能介导了许多突触处神经递质释放所需的对ω-芋螺毒素敏感的钙内流。
