The benzdiimidazole NAB2 rescues α-synuclein-associated trafficking defects associated with early onset Parkinson′s disease in a Nedd4-dependent manner. Despite identification of E3 ubiquitin ligase Nedd4 as a putative target of NAB2, its molecular mechanism of action has not been elucidated. As such, the effect of NAB2 on Nedd4 activity and specificity was interrogated through biochemical, biophysical, and proteomic analyses. NAB2 was found to bind Nedd4 (K_D^app = 42 nM), but this binding is side chain mediated and does not alter its conformation or ubiquitination kinetics in vitro. Nedd4 co-localizes with trafficking organelles, and NAB2 exposure did not alter its co-localization. Ubiquitin-enrichment coupled proteomics revealed that NAB2 stimulates ubiquitination of trafficking and transport associated proteins, most likely through modulating the substrate specificity of Nedd4, providing a putative protein network involved in the NAB2 mechanism.

中文翻译：

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小分子通过Nedd4泛素信号级联反应诱导帕金森氏相关运输变化的特征

苯并二咪唑NAB2以依赖Nedd4的方式挽救与帕金森氏病早期发作有关的α-突触核蛋白相关的运输缺陷。尽管将E3泛素连接酶Nedd4鉴定为NAB2的假定靶标，但其分子作用机理尚未阐明。这样，通过生化，生物物理和蛋白质组学分析来询问NAB2对Nedd4活性和特异性的影响。发现NAB2绑定Nedd4（K _D ^app＝ 42nM），但是该结合是侧链介导的，并且在体外不改变其构象或泛素化动力学。Nedd4与贩运细胞器共定位，而NAB2暴露并未改变其共定位。泛素富集偶联的蛋白质组学研究表明，NAB2刺激运输和运输相关蛋白的泛素化，最有可能通过调节Nedd4的底物特异性，从而提供一个参与NAB2机制的推定蛋白网络。