Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary.
Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary.
FEBS Lett. 2014 Jan 31;588(3):408-13. doi: 10.1016/j.febslet.2013.12.012. Epub 2013 Dec 24.
The Atg2-Atg18 complex acts in parallel to Atg8 and regulates Atg9 recycling from phagophore assembly site (PAS) during autophagy in yeast. Here we show that in Drosophila, both Atg9 and Atg18 are required for Atg8a puncta formation, unlike Atg2. Selective autophagic degradation of ubiquitinated proteins is mediated by Ref(2)P/p62. The transmembrane protein Atg9 accumulates on refractory to Sigma P (Ref(2)P) aggregates in Atg7, Atg8a and Atg2 mutants. No accumulation of Atg9 is seen on Ref(2)P in cells lacking Atg18 or Vps34 lipid kinase function, while the Atg1 complex subunit FIP200 is recruited. The simultaneous interaction of Atg18 with both Atg9 and Ref(2)P raises the possibility that Atg18 may facilitate selective degradation of ubiquitinated protein aggregates by autophagy.
Atg2-Atg18 复合物与 Atg8 平行作用，调节酵母自噬过程中噬泡组装位点（PAS）处的 Atg9 循环。在这里，我们发现果蝇中，Atg9 和 Atg18 都需要 Atg8a 点状形成，而 Atg2 不需要。泛素化蛋白的选择性自噬降解是由 Ref(2)P/p62 介导的。跨膜蛋白 Atg9 在 Atg7、Atg8a 和 Atg2 突变体中积累在 Sigma P (Ref(2)P) 聚集体上。在缺乏 Atg18 或 Vps34 脂质激酶功能的细胞中，看不到 Atg9 在 Ref(2)P 上的积累，而 Atg1 复合物亚基 FIP200 被招募。Atg18 与 Atg9 和 Ref(2)P 的同时相互作用提出了 Atg18 可能通过自噬促进泛素化蛋白聚集体的选择性降解的可能性。
