Atg9A trafficking through the recycling endosomes is required for autophagosome formation

Kenta Imai, Feike Hao, Naonobu Fujita, Yasuhiro Tsuji, Yukako Oe, Yasuhiro Araki, Maho Hamasaki, Takeshi Noda, Tamotsu Yoshimori

    Research output: Contribution to journalArticlepeer-review

    52 Citations (Scopus)

    Abstract

    Autophagy is an intracellular degradation pathway conserved in eukaryotes. Among core autophagy-related (Atg) proteins, mammalian Atg9A is the sole multi-spanning transmembrane protein, and both of its N- and C-terminal domains are exposed to the cytoplasm. It is known that Atg9A travels through the trans-Golgi network (TGN) and the endosomal system under nutrient-rich conditions, and transiently localizes to the autophagosome upon autophagy induction. However, the significance of Atg9A trafficking for autophagosome formation remains elusive. Here, we identified sorting motifs in the N-terminal cytosolic stretch of Atg9A that interact with the adaptor protein AP-2. Atg9A with mutations in the sorting motifs could not execute autophagy and was abnormally accumulated at the recycling endosomes. The combination of defects in autophagy and Atg9A accumulation in the recycling endosomes was also found upon the knockdown of TRAPPC8, a specific subunit of the TRAPPIII complex. These results show directly that the trafficking of Atg9A through the recycling endosomes is an essential step for autophagosome formation.

    Original languageEnglish
    Pages (from-to)3781-3791
    Number of pages11
    JournalJournal of cell science
    Volume129
    Issue number20
    DOIs
    Publication statusPublished - 2016

    Keywords

    • AP-2
    • Atg9
    • Autophagy
    • Golgi
    • Recycling endosome
    • Sorting motif
    • TRAPP

    ASJC Scopus subject areas

    • Cell Biology

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