TRP2: A candidate transduction channel for mammalian pheromone sensory signaling
TRP2: A candidate transduction channel for mammalian pheromone sensory signaling
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DOI：
10.1073/pnas.96.10.5791
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发表时间：
1999-05-11
影响因子：
11.1
通讯作者：
Dulac, C
中科院分区：
文献类型：
--
作者：
Liman, ER;Corey, DP;Dulac, C
陆生脊椎动物的犁鼻器 (VNO) 在信息素检测中起着关键作用，信息素是动物释放的化学物质，可在同种动物中引发刻板的性行为和攻击行为。VNO 中的感觉转导似乎与脊椎动物的嗅觉和视觉系统中的感觉转导无关：VNO 的假定信息素受体在进化上独立于气味受体，并且与脊椎动物的视觉和视觉系统相反。嗅觉转导、犁鼻转导不太可能由环核苷酸门控通道介导。我们假设 VNO 中的感觉转导可能涉及瞬时受体电位 (TRP) 家族的离子通道，该家族的成员在果蝇和秀丽隐杆线虫中介导不依赖环核苷酸的感觉反应，并在哺乳动物中发挥未知的功能。我们从大鼠 VNO 中分离出 cDNA (rTRP2)，编码 885 个氨基酸的蛋白质，该蛋白质与脊椎动物和无脊椎动物 TRP 通道的距离相同（10-30% 氨基酸同一性）。 rTRP2 mRNA 专门在 VNO 神经元中表达，并且该蛋白高度定位于 VNO 感觉微绒毛，即信息素感觉转导的拟议位点。感觉微绒毛中不存在 Ca2+ 储存，这表明，与拟议的哺乳动物 TRP 通道激活机制相反，但根据果蝇光转导中 TRP 功能的分析，TRP2 的门控独立于内部 Ca2+ 储存的消耗。因此，TRP2 可能参与犁鼻感觉转导，这可能与果蝇眼睛中光诱导的信号传导有更多的相似之处。
The vomeronasal organ (VNO) of terrestrial vertebrates plays a key role in the detection of pheromones, chemicals released by animals that elicit stereotyped sexual and aggressive behaviors among conspecifics, Sensory transduction in the VNO appears unrelated to that in the vertebrate olfactory and visual systems: the putative pheromone receptors of the VNO are evolutionarily independent from the odorant receptors and, in contrast to vertebrate visual and olfactory transduction, vomeronasal transduction is unlikely to be mediated by cyclic-nucleotide-gated channels. We hypothesized that sensory transduction in the VNO might instead involve an ion channel of the transient receptor potential (TRP) family, members of which mediate cyclic-nucleotide-independent sensory responses in Drosophila melanogaster and Caenorhabditis elegans and play unknown functions in mammals. We have isolated a cDNA (rTRP2) from rat VNO encoding a protein of 885 amino acids that is equally distant from vertebrate and invertebrate TRP channels (10-30% amino acid identity). rTRP2 mRNA is exclusively expressed in VNO neurons, and the protein is highly localized to VNO sensory microvilli, the proposed site of pheromone sensory transduction, The absence of Ca2+ stores in sensory microvilli suggests that, in contrast to a proposed mechanism of activation of mammalian TRP channels, but in accord with analysis of TRP function in Drosophila phototransduction, the gating of TRP2 is independent from the depletion of internal Ca2+ stores. Thus, TRP2 is likely to participate in vomeronasal sensory transduction, which may share additional similarities with light-induced signaling in the Drosophila eye.