V-ATPase engagement in autophagic processes.

The proton pumping activity of V-ATPase is responsible for acidification of the lysosome/vacuole. The low lumenal pH of this organelle stimulates the activity of a battery of resident hydrolases responsible for the degradation of various nonselective and selective cargos delivered by autophagic processes. However, the role of V-ATPase in membrane dynamics required for the uptake of autophagic cargo is far from fully understood. Consideration of the available data leads us to speculate that autophagic processes involving direct membrane-to-membrane contacts between the selected cargo and the vacuolar membrane require functional V-ATPase.