The V-ATPase/ATG16L1 axis is controlled by the V1H subunit
Lewis Timimi, Antoni G. Wrobel, George N. Chiduza, Sarah Maslen, Antonio Torres-Méndez, Beatriz Montaner, Colin Davis, Taylor F. Minckley, Katriona L. Hole, Andrea Serio, Michael J. Devine, Mark Skehel, John L. Rubinstein, Anne Schreiber, Rupert Beale
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 V 1 H subunit of the vacuolar ATPase (V-ATPase) proton pump binds directly to ATG16L1. The V 1 H/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 V 1 H fail to target ATG8s during influenza infection or after activation of the immune receptor stimulator of interferon genes (STING). We identify a loop within V 1 H that mediates ATG16L1 binding. A neuronal V 1 H isoform lacks this loop and is associated with attenuated ATG8 targeting in response to ionophores in primary murine and human iPSC-derived neurons. Thus, V 1 H controls ATG16L1 recruitment following proton gradient dissipation, suggesting that the V-ATPase acts as a cell-intrinsic damage sensor.