Proteomic and biochemical analyses reveal a novel mechanism for promoting protein ubiquitination and degradation by UFBP1, a key component of ufmylation
Proteomic and biochemical analyses reveal a novel mechanism for promoting protein ubiquitination and degradation by UFBP1, a key component of ufmylation
复制标题
蛋白质组学和生化分析揭示了 UFBP1（ufmylation 的关键组成部分）促进蛋白质泛素化和降解的新机制
DOI：
10.1021/acs.jproteome.7b00843
复制
发表时间：
2018
影响因子：
4.4
通讯作者：
Guoqiang Xu
中科院分区：
文献类型：
--
作者：
Ying Zhu;Qing Lei;Dan Li;Yang Zhang;Xiaogang Jiang;Zhanhong Hu;Guoqiang Xu
泛素折叠修饰剂 1 (UFM1) 进行的蛋白质翻译后修饰可调节许多生物过程，例如对内质网应激的反应和肿瘤进展的调节。最近的一项研究表明，UFM1 结合和包含 PCI 结构域的蛋白 1 (UFBP1) 是 UFM1 与底物缀合所必需的。然而，UFBP1 的其他生物学功能尚未被探索。在这里，我们使用免疫沉淀和无标记定量蛋白质组学来鉴定哺乳动物细胞系中的 UFBP1 相互作用蛋白。从三个生物重复的 MS 分析中获得了大约 80 种潜在的相互作用蛋白。这些蛋白质的生物信息学分析表明 UFBP1 可能参与蛋白质折叠、稳定性和运输的调节。生化实验发现，UFBP1 表达下调蛋白质水平并降低其几种相互作用蛋白质的稳定性，而 UFBP1 敲低则增加其蛋白质水平。蛋白质合成抑制和蛋白酶体抑制实验表明UFBP1促进其泛素化和降解。使用模型 UFBP1 相互作用蛋白 ANT3 进行的实验表明，UFBP1 增强了 ANT3 与其 E3 连接酶之间的相互作用，从而促进其泛素化和降解。我们的工作阐明了 UFBP1 调节蛋白质泛素化和降解的新分子机制。
Protein post-translational modification by ubiquitin-fold modifier 1, UFM1, regulates many biological processes such as response to endoplasmic reticulum stress and regulation of tumor progression. A recent study has indicated that the UFM1-binding and PCI domain-containing protein 1 (UFBP1) is required for the conjugation of UFM1 to a substrate. However, other biological functions of UFBP1 have not been explored. Here, we use immunoprecipitation and label-free quantitative proteomics to identify UFBP1-interacting proteins in a mammalian cell line. About 80 potential interacting proteins are obtained from MS analyses of three biological replicates. Bioinformatics analyses of these proteins suggest that UFBP1 may participate in the regulation of protein folding, stability, and trafficking. Biochemical experiments discover that UFBP1 expression downregulates the protein level and reduces the stability of several of its interacting proteins, while UFBP1 knockdown increases their protein levels. Protein synthesis inhibition and proteasomal inhibition experiments reveal that UFBP1 promotes their ubiquitination and degradation. Experiments using a model UFBP1-interacting protein ANT3 demonstrate that UFBP1 enhances the interaction between ANT3 and its E3 ligase and thus promotes its ubiquitination and degradation. Our work elucidates a novel molecular mechanism by which UFBP1 regulates protein ubiquitination and degradation.