The V-ATPase/ATG16L1 axis is controlled by the V1H subunit

Mol Cell. 2024 Aug 8;84(15):2966-2983.e9. doi: 10.1016/j.molcel.2024.07.003. Epub 2024 Jul 31.

Abstract

Defects in organellar acidification indicate compromised or infected compartments. Recruitment of the autophagy-related ATG16L1 complex to pathologically neutralized organelles targets ubiquitin-like ATG8 molecules to perturbed membranes. How this process is coupled to proton gradient disruption is unclear. Here, we reveal that the V1H subunit of the vacuolar ATPase (V-ATPase) proton pump binds directly to ATG16L1. The V1H/ATG16L1 interaction only occurs within fully assembled V-ATPases, allowing ATG16L1 recruitment to be coupled to increased V-ATPase assembly following organelle neutralization. Cells lacking V1H fail to target ATG8s during influenza infection or after activation of the immune receptor stimulator of interferon genes (STING). We identify a loop within V1H that mediates ATG16L1 binding. A neuronal V1H isoform lacks this loop and is associated with attenuated ATG8 targeting in response to ionophores in primary murine and human iPSC-derived neurons. Thus, V1H controls ATG16L1 recruitment following proton gradient dissipation, suggesting that the V-ATPase acts as a cell-intrinsic damage sensor.

Keywords: ATG16L1; ATP6V1H; CASM; STING; V-ATPase; VAIL; autophagy; influenza; non-canonical autophagy; vacuolar ATPase.

MeSH terms

  • Animals
  • Autophagy
  • Autophagy-Related Protein 8 Family / genetics
  • Autophagy-Related Protein 8 Family / metabolism
  • Autophagy-Related Proteins* / genetics
  • Autophagy-Related Proteins* / metabolism
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • HEK293 Cells
  • Humans
  • Induced Pluripotent Stem Cells / metabolism
  • Influenza, Human / genetics
  • Influenza, Human / metabolism
  • Influenza, Human / virology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neurons / metabolism
  • Protein Binding
  • Signal Transduction
  • Vacuolar Proton-Translocating ATPases* / genetics
  • Vacuolar Proton-Translocating ATPases* / metabolism

Substances

  • Vacuolar Proton-Translocating ATPases
  • Autophagy-Related Proteins
  • ATG16L1 protein, human
  • Atg16l1 protein, mouse
  • Autophagy-Related Protein 8 Family
  • Carrier Proteins