2026-08-31 東京科学大学
図1. Atg23によるAtg9小胞の保護と脱保護
＜関連情報＞
- https://www.isct.ac.jp/ja/news/zlsqztq43a2m
- https://link.springer.com/article/10.1038/s44318-026-00867-0
Atg23は、オートファゴソーム形成部位への輸送中にAtg9小胞の異常な融合を防ぐ Atg23 prevents aberrant fusion of Atg9 vesicles during delivery to autophagosome formation sites
Takumi Kimura,Takayuki Shima,Tetsuya Kotani & Hitoshi Nakatogawa
The EMBO Journal Published:20 July 2026
DOI:https://doi.org/10.1038/s44318-026-00867-0
Abstract
Autophagosome biogenesis depends on the accurate delivery of membrane lipids to the pre-autophagosomal structure. Golgi/endosome-derived Atg9 vesicles provide the membrane seed for this process, but how they are trafficked through the cytoplasm while avoiding inappropriate fusion remains unclear. Here we show that in Saccharomyces cerevisiae, the soluble Atg9-interacting protein Atg23 remains associated with Atg9 vesicles after their biogenesis. This association shields Atg9 vesicles from aberrant SNARE-dependent fusion as they diffuse through the cytoplasm en route to the autophagosome formation site. We further show that upon vesicle arrival at the site, Atg9 phosphorylation by the autophagy initiation kinase Atg1 releases Atg23, facilitating recruitment of the downstream factor Atg2, a lipid transfer protein for membrane expansion. Together, these findings reveal an Atg1-dependent phosphorylation switch that regulates Atg9 vesicle dynamics during autophagosome biogenesis.
