bims-nocaut Biomed News
on Non-canonical autophagy
Issue of 2026–09–20
three papers selected by
Quentin Frenger, University of Strasbourg



  1. Nat Cell Biol. 2026 Sep 15.
      Lysosomal membrane integrity is essential for preserving cellular homeostasis in response to different stressors. Upon lysosomal membrane permeabilization, cells activate several mechanisms for lysosomal membrane repair, including ESCRT proteins, phosphatidylinositol 4-phosphate (PI4P)-dependent lipid transfer from the endoplasmic reticulum (ER) and conjugation of ATG8 family proteins to single membranes (CASM). The interplay between these pathways and the regulation of the lipid transfer machinery remain incompletely understood. Here we show that phosphatidylinositol 3-phosphate (PI3P)-containing ER domains play a major role in lysosomal membrane repair. PI3P is formed on lysosome-proximal ER domains by the phosphatidylinositol 3-kinase PIK3C3/VPS34 in response to membrane damage, and inhibition or depletion of PIK3C3 inhibits lysosome repair. Mechanistically, the ATPase DFCP1/ZFYVE1 accumulates on lysosome-proximal ER domains by its PI3P binding, triggered by Ca2+ efflux from lysosomes and requiring the ULK1 kinase complex and ER proteins of the VAP family. Downstream of CASM, PI4P, ESCRTs and PI3P, DFCP1 promotes focal accumulation of the lipid channel VPS13C on ER domains proximal to damaged lysosomes to promote their repair. The function and dynamics of DFCP1 depend on its ability to bind and hydrolyse ATP, and absence of DFCP1 compromises cellular resistance to vacuolar damage induced by Listeria monocytogenes. We conclude that DFCP1 mediates concentration of the ER-associated lipid transport machinery at damaged lysosomes to promote their sealing in response to Ca2+ flux and PIK3C3 activation.
    DOI:  https://doi.org/10.1038/s41556-026-02062-z
  2. Autophagy Rep. 2026 ;5(1): 2728537
      The cGAS-STING pathway detects cytosolic dsDNA to initiate innate immune responses, serving as a critical surveillance system against infection and cellular stress. Autophagy is an evolutionarily conserved catabolic process that maintains homeostasis by degrading cytoplasmic components. Although these two systems operate through distinct mechanisms, recent studies have uncovered a complex bidirectional regulatory network that intimately links them. On the one hand, STING has an evolutionarily conserved capacity to induce TBK1-independent noncanonical autophagy, and recent studies further link this activity to TFEB-dependent lysosome biogenesis, expanding its functional repertoire beyond classical interferon induction. On the other hand, autophagy restricts cGAS-STING signaling by clearing cytosolic DNA and selectively degrading pathway components, thereby preventing excessive inflammation. Furthermore, mitophagy curtails the release of mitochondrial DNA, a potent cGAS agonist, and recent studies further implicate lysosomes as active signaling platforms associated with mtDNA release, LRRK2 activation, and STING-dependent NF-κB responses. In this review, we discuss recent advances in understanding how the cGAS-STING pathway and autophagy mutually regulate each other at the cellular level, focusing on the molecular mechanisms of this interplay, both canonical and noncanonical, and highlighting how their crosstalk shapes cellular homeostasis and stress adaptation.
    Keywords:  cGAS-STING pathway; innate immunity; lysosome; mitophagy; mtDNA; non-canonical autophagy
    DOI:  https://doi.org/10.1080/27694127.2026.2728537
  3. Nat Commun. 2026 Aug 13. pii: 9750. [Epub ahead of print]17(1):
      Megakaryocytes (MKs) are polyploid cells that maintain bone marrow homeostasis by secreting cytokines, including transforming growth factor β1 (TGFβ1). During neoplastic transformation, MKs accumulate in the bone marrow, promoting fibrotic remodeling that leads to myelofibrosis. However, the therapeutic potential of targeting MK cytokine secretion remains poorly understood. Because unconventional secretion of TGFβ1 and interleukin 1β (IL1β) via secretory autophagy occurs in other cell types, we investigated whether MKs may utilize the same mechanism. Disrupting secretory autophagy, or inhibiting the small GTPase RhoA or its downstream effector Rho-associated kinase (ROCK), markedly reduced TGFβ1 and IL1β secretion in vitro. Conditional deletion of the autophagy gene Atg5 in the hematopoietic system limited megakaryocytosis and aberrant cytokine secretion in an MPLW515L-driven transplant model, while MK-specific deletion of Rhoa protected mice from fibrosis. Ultimately, ROCK inhibition, alone or combined with a JAK2 inhibitor, also attenuated disease hallmarks, identifying the RhoA-secretory autophagy axis as a promising therapeutic target in myelofibrosis.
    DOI:  https://doi.org/10.1038/s41467-026-76615-z