Integrated proteomics identifies p62-dependent selective autophagy of the supramolecular vault complex
Integrated proteomics identifies p62-dependent selective autophagy of the supramolecular vault complex
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DOI：
10.1016/j.devcel.2023.04.015
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发表时间：
2023-07-10
影响因子：
11.8
通讯作者：
Komatsu, Masaaki
中科院分区：
文献类型：
--
作者：
Kurusu, Reo;Fujimoto, Yuki;Komatsu, Masaaki
除了膜细胞器外，自噬还选择性地降解生物分子凝聚体，特别是 p62/SQSTM1 体，以预防包括癌症在内的疾病。关于自噬降解 p62 体的机制的证据越来越多，但对其成分知之甚少。在这里，我们利用人类细胞系建立了一种基于荧光激活颗粒分选的 p62 体纯化方法，并通过质谱法测定了其成分。结合选择性自噬缺陷小鼠组织的质谱分析，我们确定了Vault（一种大型超分子复合物）作为p62体内的货物。从机制上讲，主要穹窿蛋白直接与 NBR1（一种 p62 相互作用蛋白）相互作用，将穹窿招募到 p62 体中以进行有效降解。这个过程被称为穹窿吞噬，调节体内稳态穹窿水平，其损伤可能与非酒精性脂肪性肝炎衍生的肝细胞癌有关。我们的研究提供了一种识别相分离介导的选择性自噬货物的方法，扩大了我们对相分离在蛋白质稳态中作用的理解。
In addition to membranous organelles, autophagy selectively degrades biomolecular condensates, in particular p62/SQSTM1 bodies, to prevent diseases including cancer. Evidence is growing regarding the mechanisms by which autophagy degrades p62 bodies, but little is known about their constituents. Here, we established a fluorescence-activated-particle-sorting-based purification method for p62 bodies using human cell lines and determined their constituents by mass spectrometry. Combined with mass spectrometry of selective-autophagy-defective mouse tissues, we identified vault, a large supramolecular complex, as a cargo within p62 bodies. Mechanistically, major vault protein directly interacts with NBR1, a p62-interacting protein, to recruit vault into p62 bodies for efficient degradation. This process, named vault-phagy, regulates homeostatic vault levels in vivo, and its impairment may be associated with non-alcoholic-steatohepatitisderived hepatocellular carcinoma. Our study provides an approach to identifying phase-separation -mediated selective autophagy cargoes, expanding our understanding of the role of phase separation in proteostasis.