bims-nocaut Biomed News
on Non-canonical autophagy
Issue of 2026–08–16
two papers selected by
Quentin Frenger, University of Strasbourg
  1. An expanding role for ATG8s and ATG8 E3-like ligases in maintaining membrane integrity.
  2. Mechanism of Autophagic Extracellular Vesicles Revealed.
  1. Autophagy. 2026 Aug 13. 1-11
    An expanding role for ATG8s and ATG8 E3-like ligases in maintaining membrane integrity.
    Dale P Corkery, Yao-Wen Wu.
      Endolysosomal membranes are frequently damaged by pathogenic stress associated with aging, infection, and neurodegeneration, and failure to repair such damage leads to inflammation and cell death. Recent advances identify membrane ATG8 conjugation (atg8ylation) as a key process that links damage detection to coordinated lysosomal repair, removal, and regeneration. Beyond its canonical role in macroautophagy, membrane atg8ylation also occurs on preexisting, non-autophagosomal single membranes through Conjugation of ATG8s to Single Membranes (CASM), positioning this pathway as a rapid response to membrane stress. Two E3-like ligase complexes, ATG16L1-ATG5-ATG12 and TECPR1-ATG5-ATG12, act as complementary sensors of lysosomal injury by detecting distinct physicochemical cues, including proton gradient collapse and lipid scrambling. These ligases convert damage signals into spatially restricted membrane atg8ylation, generating a membrane-associated platform that coordinates multiple downstream pathways. These include ESCRT-dependent membrane repair, ER-lysosome lipid transfer, membrane tubulation, and stress granule formation. When repair fails, membrane atg8ylation regulates lysophagy and activates lysosomal biogenesis and regeneration to restore lysosomal homeostasis. These emerging findings define membrane atg8ylation as a central organizer of membrane quality control rather than a pathway merely confined to macroautophagy. In this review, we summarize the current understanding of how membrane atg8ylation detects lysosomal damage and how this pathway coordinates other lysosomal quality control mechanisms to maintain lysosomal integrity.
    Keywords:  CASM; Lysosome; lysosomal membrane integrity; membrane atg8ylation; noncanonical autophagy
    DOI:  https://doi.org/10.1080/15548627.2026.2704442
  2. Traffic. 2026 Sep;27(3): e70045
    Mechanism of Autophagic Extracellular Vesicles Revealed.
    Constantinos Demetriades, Thierry Galli.
      Recent work by Mao and colleagues identifies a distinct class of small extracellular vesicles, termed autophagic extracellular vesicles (AEVs), generated from amphisomes upon autophagy induction. In this commentary, we discuss how this study provides important mechanistic insight into the coupling between autophagy and secretion. AEVs are molecularly and functionally distinct from canonical exosomes, being enriched in autophagy-related components such as LC3 and p62, and dependent on core ATG machinery for their biogenesis. Notably, their secretion is enhanced by autophagy induction and contributes to intercellular communication, particularly in the context of viral infection. These findings position amphisomes as critical sorting hubs that direct cargo toward either degradation or secretion, thereby integrating autophagic and endolysosomal pathways. We further highlight how these results intersect with prior evidence implicating SNARE-dependent mechanisms, including VAMP7 and stress-responsive regulators such as GRASP55, in unconventional secretion. Finally, we discuss key unresolved questions, particularly the mechanisms underlying the generation of small intraluminal vesicles within amphisomes and the role of ESCRT machinery in this process. Overall, the identification of AEVs adds a new layer of complexity to extracellular vesicle biology and opens new avenues for understanding how autophagy contributes to intercellular signaling in health and disease.
    DOI:  https://doi.org/10.1111/tra.70045
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