Proximity Proteomics and Biochemical Analysis Reveal a Noncanonical Function for UFM1-Specific Protease 1 in the p62 Body Formation.
Proximity Proteomics and Biochemical Analysis Reveal a Noncanonical Function for UFM1-Specific Protease 1 in the p62 Body Formation.
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DOI：
10.1021/acs.jproteome.3c00107
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发表时间：
2023-06
影响因子：
4.4
通讯作者：
Xiaohui Wang;Lindong Cao;Honglv Jiang;Liang Zhou;Zhanhong Hu;Guoqiang Xu
中科院分区：
文献类型：
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作者：
Xiaohui Wang;Lindong Cao;Honglv Jiang;Liang Zhou;Zhanhong Hu;Guoqiang Xu
蛋白质聚集体在神经退行性疾病的发展中起着至关重要的作用，而p62是调节蛋白质聚集体形成的关键蛋白之一。最近，已经发现在UFM 1-缀合系统中的几种关键酶包括UFM 1-活化酶UBA 5、UFM 1-缀合酶UFC 1、UFM 1-蛋白连接酶UFL 1和UFM 1-特异性蛋白酶UfSP 2的缺失诱导p62积累以在胞质溶胶中形成p62体。然而，目前尚不清楚UfSP 1是否参与p62小体的形成，以及该过程是否需要其酶活性。在这里，邻近标记技术和定量蛋白质组学鉴定SQSTM 1/p62作为UfSP 1相互作用蛋白。免疫共沉淀显示p62确实与UfSP 1相互作用，免疫荧光实验揭示UfSP 1与p62共定位并促进p62介导的蛋白质聚集体的形成。机制研究揭示UfSP 1与p62的泛素相关结构域结合，促进p62与泛素化蛋白之间的相互作用，从而增加p62体的形成。有趣的是，我们进一步证明了催化活性和非活性UfSP 1通过相同的机制促进p62小体的形成。总之，这项工作发现，UfSP 1表现出非典型的功能，独立于其蛋白酶活性的p62体的形成。
Protein aggregates play crucial roles in the development of neurodegenerative diseases and p62 is one of the key proteins regulating the formation of protein aggregates. Recently, it has been discovered that depletion of several key enzymes including UFM1-activating enzyme UBA5, UFM1-conjugating enzyme UFC1, UFM1-protein ligase UFL1, and UFM1-specific protease UfSP2 in the UFM1-conjugation system induces p62 accumulation to form p62 bodies in the cytosol. However, it is unknown whether UfSP1 participates in the formation of p62 bodies and whether its enzymatic activity is required for this process. Here, the proximity labeling technique and quantitative proteomics identify SQSTM1/p62 as a UfSP1-interacting protein. Coimmunoprecipitation reveals that p62 indeed interacts with UfSP1 and the immunofluorescence experiment discloses that UfSP1 colocalizes with p62 and promotes the formation of p62-mediated protein aggregates. Mechanistic studies unveil that UfSP1 binds to the ubiquitin-associated domain of p62 and promotes the interaction between p62 and ubiquitinated proteins, thereby increasing the formation of p62 bodies. Interestingly, we further demonstrate that both the catalytic active and inactive UfSP1 promote the formation of p62 bodies through the same mechanism. Taken together, this work discovers that UfSP1 exhibits a noncanonical function independent of its protease activity in the p62 body formation.