TAR DNA-binding protein 43 (TDP-43) is a nuclear RNA/DNA binding protein involved in mRNA metabolism. Aberrant mislocalization to the cytoplasm and formation of phosphorylated/aggregated TDP-43 inclusions remains the hallmark pathology in a spectrum of neurodegenerative diseases, including frontotemporal disorders and Alzheimer's disease. Eukaryotic Translation Initiation Factor 5A undergoes a unique post-translation modification of lysine to hypusine (K50), which determines eIF5A binding partners. We used a sodium arsenite-induced cellular stress model to investigate the role of hypusinated eIF5A (eIF5A^HypK50) in governing TDP-43 cytoplasmic mislocalization and accumulation in stress granule. Our proteomics and functional data provide evidence that eIF5A interacts with TDP-43 in a hypusine-dependent manner. Additionally, we showed that following stress TDP-43 interactions with eIF5A^HypK50 were induced both in the cytoplasm and stress granules. Pharmacological reduction of hypusination or mutations of lysine residues within the hypusine loop decreased phosphorylated and insoluble TDP-43 levels. The proteomic and biochemical analysis also identified nuclear pore complex importins KPNA1/2, KPNB1, and RanGTP as interacting partners of eIF5A^HypK50. These findings are the first to provide a novel pathway and potential therapeutic targets that require further investigation in models of TDP-43 proteinopathies.

TAR DNA结合蛋白43（TDP-43）是参与mRNA代谢的核RNA / DNA结合蛋白。在许多神经退行性疾病，包括额颞叶疾病和阿尔茨海默氏病中，异常的细胞定位错误和磷酸化/聚集的TDP-43内含物的形成仍是标志性病理。真核翻译起始因子5A经历了赖氨酸到hysupsine（K50）的独特翻译后修饰，这决定了eIF5A的结合伴侣。我们使用亚砷酸钠诱导的细胞应激模型来研究^神经素化eIF5A（eIF5A ^HypK50）来控制TDP-43细胞质在应激颗粒中的定位错误和积累。我们的蛋白质组学和功能数据提供了eIF5A与TDP-43相互作用的证据，依赖于酪氨酸。此外，我们表明，在细胞质和应激颗粒中均诱导了应激TDP-43与eIF5A ^HypK50的相互作用。药理学上减少了hypusification或hysupsine环内的赖氨酸残基的突变降低了磷酸化和不溶性TDP-43水平。蛋白质组学和生化分析还确定了核孔复合体输入蛋白KPNA1 / 2，KPNB1和RanGTP是eIF5A ^HypK50的相互作用伴侣。这些发现是第一个提供新途径和潜在治疗靶点的研究，需要在TDP-43蛋白病模型中进行进一步研究。