Niemann-Pick type C2 protein mediating chemical communication in the worker ant
Niemann-Pick type C2 protein mediating chemical communication in the worker ant
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DOI：
10.1073/pnas.1323928111
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发表时间：
2014-03-11
影响因子：
11.1
通讯作者：
Yamazaki, Toshimasa
中科院分区：
文献类型：
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作者：
Ishida, Yuko;Tsuchiya, Wataru;Yamazaki, Toshimasa
蚂蚁是社会性昆虫，分布在世界大部分地区。在其种姓中，工蚁负责蚁群维护所需的各种任务。在它们的化学通讯中，α-螺旋载体蛋白、气味结合蛋白和化学感应蛋白在触角的感器淋巴液中积累，在将疏水性化学信息素转移到化学感应受体中发挥着重要作用。据推测，化学信息素被α-螺旋载体蛋白识别。然而，这些蛋白质的数量不足以与从化学感应受体基因估计的大量化学信息素相互作用。在这里，我们通过从日本工蚁弓背蚁 (CjapNPC2) 的触角中鉴定出尼曼-皮克 C2 型 (NPC2) 蛋白，揭示了这个难题。 CjapNPC2在基本感器的感器腔中积累。 CjapNPC2 的配体结合口袋由灵活的 β 结构组成，使其能够与多种潜在的化学信息素结合。一些化学信息素在工作天线中引起电生理反应。在脊椎动物中，NPC2 充当胆固醇从晚期内体和溶酶体到其他细胞器的重要载体蛋白。然而，蚂蚁进化出了具有可延展配体结合袋的 NPC2，作为基本感器的感器腔中的中等选择性载体蛋白。 CjapNPC2 可能能够向化学感应受体神经元传递各种疏水性化学信息素，并在执行工蚁任务所需的化学通讯中发挥关键作用。
Ants are eusocial insects that are found in most regions of the world. Within its caste, worker ants are responsible for various tasks that are required for colony maintenance. In their chemical communication, alpha-helical carrier proteins, odorant-binding proteins, and chemosensory proteins, which accumulate in the sensillum lymph in the antennae, play essential roles in transferring hydrophobic semiochemicals to chemosensory receptors. It has been hypothesized that semiochemicals are recognized by alpha-helical carrier proteins. The number of these proteins, however, is not sufficient to interact with a large number of semiochemicals estimated from chemosensory receptor genes. Here we shed light on this conundrum by identifying a Niemann-Pick type C2 (NPC2) protein from the antenna of the worker Japanese carpenter ant, Camponotus japonicus (CjapNPC2). CjapNPC2 accumulated in the sensillum cavity in the basiconic sensillum. The ligand-binding pocket of CjapNPC2 was composed of a flexible beta-structure that allowed it to bind to a wide range of potential semiochemicals. Some of the semiochemicals elicited electrophysiolgical responses in the worker antenna. In vertebrates, NPC2 acts as an essential carrier protein for cholesterol from late endosomes and lysosomes to other cellular organelles. However, the ants have evolved an NPC2 with a malleable ligand-binding pocket as a moderately selective carrier protein in the sensillum cavity of the basiconic sensillum. CjapNPC2 might be able to deliver various hydrophobic semiochemicals to chemosensory receptor neurons and plays crucial roles in chemical communication required to perform the worker ant tasks.