Molecular Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Molecular Machines and Signaling, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
Molecular Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
Mol Cell. 2020 Dec 3;80(5):764-778.e7. doi: 10.1016/j.molcel.2020.10.030. Epub 2020 Nov 17.
Autophagy eliminates cytoplasmic content selected by autophagy receptors, which link cargo to the membrane-bound autophagosomal ubiquitin-like protein Atg8/LC3. Here, we report a selective autophagy pathway for protein condensates formed by endocytic proteins in yeast. In this pathway, the endocytic protein Ede1 functions as a selective autophagy receptor. Distinct domains within Ede1 bind Atg8 and mediate phase separation into condensates. Both properties are necessary for an Ede1-dependent autophagy pathway for endocytic proteins, which differs from regular endocytosis and does not involve other known selective autophagy receptors but requires the core autophagy machinery. Cryo-electron tomography of Ede1-containing condensates, at the plasma membrane and in autophagic bodies, shows a phase-separated compartment at the beginning and end of the Ede1-mediated selective autophagy route. Our data suggest a model for autophagic degradation of macromolecular protein complexes by the action of intrinsic autophagy receptors.
自噬消除了由自噬受体连接的细胞质内容物,这些受体将货物连接到膜结合的自噬体泛素样蛋白 Atg8/LC3 上。在这里,我们报告了酵母中由内吞蛋白形成的蛋白质凝聚物的选择性自噬途径。在这个途径中,内吞蛋白 Ede1 作为选择性自噬受体发挥作用。Ede1 内的不同结构域与 Atg8 结合,并介导相分离成凝聚物。这两个特性对于依赖 Ede1 的内吞蛋白的自噬途径都是必需的,该途径与常规内吞作用不同,不涉及其他已知的选择性自噬受体,但需要核心自噬机制。在质膜和自噬体中包含 Ede1 的凝聚物的冷冻电子断层扫描显示,在 Ede1 介导的选择性自噬途径的开始和结束时存在相分离的隔室。我们的数据表明了一种通过内在自噬受体的作用来降解大分子蛋白质复合物的自噬降解模型。