Lingueglia E, Champigny G, Lazdunski M, Barbry P
Institut de Pharmacologie Moléculaire et Cellulaire, Sophia Antipolis, Valbonne, France.
Nature. 1995 Dec 14;378(6558):730-3. doi: 10.1038/378730a0.
The peptide Phe-Met-Arg-Phe-NH2 (FMRFamide) and structurally related peptides are present both in invertebrate and vertebrate nervous systems. Although they constitute a major class of invertebrate peptide neurotransmitters, the molecular structure of their receptors has not yet been identified. In neurons of the snail Helix aspersa, as well as in Aplysia bursting and motor neurons, FMRFamide induces a fast excitatory depolarizing response due to direct activation of an amiloride-sensitive Na+ channel. We have now isolated a complementary DNA from Helix nervous tissue; when expressed in Xenopus oocytes, it encodes an FMRFamide-activated Na+ channel (FaNaCh) that can be blocked by amiloride. The corresponding protein shares a very low sequence identity with the previously cloned epithelial Na+ channel subunits and Caenorhabditis elegans degenerins, but it displays the same overall structural organization. To our knowledge, this is the first characterization of a peptide-gated ionotropic receptor.
肽Phe-Met-Arg-Phe-NH2（FMRF酰胺）及结构相关肽存在于无脊椎动物和脊椎动物的神经系统中。尽管它们构成了无脊椎动物肽类神经递质的主要类别，但其受体的分子结构尚未确定。在蜗牛Helix aspersa的神经元以及海兔的爆发神经元和运动神经元中，FMRF酰胺由于直接激活了氨氯地平敏感的Na+通道而诱导快速兴奋性去极化反应。我们现已从Helix神经组织中分离出一个互补DNA；当在非洲爪蟾卵母细胞中表达时，它编码一种可被氨氯地平阻断的FMRF酰胺激活的Na+通道（FaNaCh）。相应的蛋白质与先前克隆的上皮Na+通道亚基和秀丽隐杆线虫退化蛋白的序列同一性非常低，但它具有相同的整体结构组织。据我们所知，这是对肽门控离子型受体的首次表征。
