Profiling local translatomes and RNA binding proteins of somatosensory neurons reveals specializations of individual axons [RIP-seq]

Individual neurons have one or more axons that often extend long distances and traverse multiple microenvironments, yet it is not known how the composition of individual axons is established or locally modulated to enable neuronal plasticity. Here, we use spatial translatomics to identify local axonal translatomes in anatomically and functionally specialized neurons in the dorsal root ganglia (DRG). DRG neurons extend long central and peripheral axons in separate directions and through distinct microenvironments to enable somatosensation. Using Translating Ribosome Affinity Purification and RNA sequencing, we generated a comprehensive resource of mRNAs preferentially translated within each axon. Locally translated proteins include pain receptors, ion channels, and translational machinery, which establish distinct electrophysiologic properties and regenerative capacities for each axon. Furthermore, we identify RNA-binding proteins associated with sorting and transporting functionally related mRNAs. These findings provide resources for addressing how axonal translation shapes the spatial organization of neurons and enables subcellular neuroplasticity.单个神经元拥有一条或多条轴突，这些轴突通常会长距离延伸并穿越多种微环境，但目前尚不清楚单个轴突的组成是如何确立并被局部调控，以实现神经元可塑性的。在此研究中，我们采用空间翻译组学（spatial translatomics）技术，对背根神经节（dorsal root ganglia, DRG）内具备解剖学与功能特异性的神经元的局部轴突翻译组进行了鉴定。背根神经节神经元会向不同方向延伸长距离的中枢和外周轴突，并穿越不同的微环境，以实现躯体感觉功能。我们借助翻译核糖体亲和纯化（translating ribosome affinity purification, TRAP）与RNA测序技术，构建了各轴突内优先翻译的mRNA的综合数据集。局部翻译的蛋白质包括疼痛受体、离子通道以及翻译相关机器，这些蛋白可为各轴突确立独特的电生理特性与再生能力。此外，我们还鉴定出了与功能相关mRNA的分选及转运过程相关的RNA结合蛋白。本研究成果为解析轴突翻译如何塑造神经元的空间组织并实现亚细胞水平的神经可塑性提供了重要研究资源。