Kawakami A, Kitsukawa T, Takagi S, Fujisawa H
Department of Molecular Biology, School of Science, Nagoya University, Japan.
J Neurobiol. 1996 Jan;29(1):1-17. doi: 10.1002/(SICI)1097-4695(199601)29:1<1::AID-NEU1>3.0.CO;2-F.
Neuropilin (previously A5) is a cell surface glycoprotein that was originally identified in Xenopus tadpole nervous tissues. In Xenopus, neuropilin is expressed on both the presynaptic and postsynaptic elements in the visual and general somatic sensory systems, suggesting a role in neuronal cell recognition. In this study, we identified a mouse homologue of neuropilin and examined its expression in developing mouse nervous tissues. cDNA cloning and sequencing revealed that the primary structure of the mouse neuropilin was highly similar to that of Xenopus and that the extracellular segment of the molecule possessed several motifs that were expected to be involved in cell-cell interaction. Immunohistochemistry and in situ hybridization analyses in mice indicated that the expression of neuropilin was restricted to particular neuron circuits. Neuropilin protein was localized on axons but not on the somata of neurons. The expression of neuropilin persisted through the time when axons were actively growing to form neuronal connections. These observations suggest that neuropilin is involved in growth, fasciculation, and targeting for a particular groups of axons.
神经纤毛蛋白（以前称为A5）是一种细胞表面糖蛋白，最初在非洲爪蟾蝌蚪的神经组织中被鉴定出来。在非洲爪蟾中，神经纤毛蛋白在视觉和一般躯体感觉系统的突触前和突触后元件上均有表达，这表明它在神经元细胞识别中发挥作用。在本研究中，我们鉴定出了神经纤毛蛋白的小鼠同源物，并检测了其在发育中的小鼠神经组织中的表达。cDNA克隆和测序显示，小鼠神经纤毛蛋白的一级结构与非洲爪蟾的高度相似，并且该分子的细胞外区域具有几个预期参与细胞间相互作用的基序。对小鼠的免疫组织化学和原位杂交分析表明，神经纤毛蛋白的表达局限于特定的神经元回路。神经纤毛蛋白定位于轴突而非神经元的胞体上。在轴突积极生长以形成神经元连接的时期，神经纤毛蛋白的表达持续存在。这些观察结果表明，神经纤毛蛋白参与特定轴突群体的生长、成束和靶向。
