bims-nocaut Biomed News
on Non-canonical autophagy
Issue of 2025–06–15
two papers selected by
Quentin Frenger, University of Strasbourg



  1. Autophagy. 2025 Jun 12.
      The autophagy mediator ATG16L1 forms part of a complex that is essential for MAP1LC3/LC3 lipidation and autophagosome formation in the canonical macroautophagic/autophagic pathway. However, ATG16L1 is also involved in unconventional activities where LC3 becomes lipidated in single-membrane structures unrelated to double-membrane autophagosomes. Such atypical activities usually require the C-terminal domain of the molecule that includes 7 WD40-type repetitions (WD40 domain, WDD). The WDD acts as a docking site for upstream inducers that engage the LC3 lipidation ability of ATG16L1 in alternative membrane compartments. Given that this domain is absent in the yeast Atg16 ortholog, an intriguing idea proposes that it was added to the primitive protein during evolution to perform new physiological roles required by the appearance of multicellularity. Identification of such atypical activities and their physiological implications at the organismal level are important issues that remain to be clarified. In a recent report we describe an unconventional autophagic pathway that restrains the immunogenic potential of apoptosis, a key feature of homeostatic and developmentally regulated cell death in multicellular organisms. This signaling route emanates from apoptotic mitochondria and induces the formation of single-membrane, LC3-positive vesicles through a mechanism that requires the WDD of ATG16L1. The induced vesicles sequester ATP to inhibit the amount of ATP released from apoptotic cells and, consequently, prevent the activation of co-cultured phagocytes. Thus, this is a pathway that contributes to maintain the immunosilent nature of apoptotic cell death.
    Keywords:  ATG16L1; ATP secretion; Apoptosis; BAK; immunogenic cell death; unconventional autophagy
    DOI:  https://doi.org/10.1080/15548627.2025.2519051
  2. Sci Adv. 2025 Jun 13. 11(24): eadu7602
      Influenza A virus (IAV) enters host cells via endocytosis, and fusion of the viral particles (VPs) at endosomes releases the viral ribonucleoproteins (vRNPs) into the cytoplasm. This uncoating step that is vital for IAV infection remains to be fully understood. The aggresome processing machinery (APM) plays a relevant but not essential role in this. Here, we reveal a mechanism in which light chain 3 proteins (LC3s) and pericentrin (PCNT) form an adaptor complex that is required for vRNPs binding to the dynein 1 and IAV uncoating at endosomes. This function of LC3s and PCNT is independent from their established role in autophagy and centrosome assembly, respectively. LC3s or PCNT depletion severely impairs IAV cytoplasm entry and infection, which can be further inhibited by additional silencing of histone deacetylase 6, an APM component. Collectively, our results show that IAV has adopted two redundant strategies to hijack the dynein biomolecular motors and facilitate VP uncoating.
    DOI:  https://doi.org/10.1126/sciadv.adu7602