V-ATPase acidification of vacuoles and lysosomes

The vacuolar H+-ATPase (V-ATPase) acidifies the lumen of lysosomes, lytic vacuoles, endosomes and other organelles of the endomembrane system. It is a rotary motor: ATP hydrolysis by the soluble V1 sector (subunits A, B, C, D, E, F, G, H) turns a central rotor that spins the membrane V0 proteolipid ring (c subunits, with a, d and e) past the a subunit, moving protons into the lumen. This module is the eukaryote-wide subunit set, written so that it can be evaluated in any genome.

Eukaryote-wide scope: every subunit family here has members across animals, fungi, Dictyostelium and Arabidopsis in its interpro/panther/<PTHR>/<PTHR>-entries.csv, and each step cites a PAINT node that the human representative descends from. Nodes placed at Eukaryota (taxon:2759): B, C, D, G, H, d and e. The source PAINT rows give no taxon for the A, E, F, a and c-ring nodes; their seed sources are recorded on each node. Read as a satisfiability rule, every subunit except e is expected in any eukaryote, because acidified endolysosomal compartments are universal; e is optional because it is small and its detection in a new genome is uncertain (see the V0 subunit e part). Molecular functions come from the human gene reviews' core functions where there is one (A, G, H, c; B from its contributes-to function) and otherwise from the node's F IBD (C, D, E, a, d); F carries neither and is untyped. The rotary-ATPase activity belongs to the assembled complex; the per-subunit terms record what each review or node asserts and are not a decomposition of that activity. The selectors test for each subunit family, not for the compartment-targeting a-subunit isoforms (a1-a4 in mammals, Vph1/Stv1 in yeast). Not yet modelled: the ER assembly factors (Vma21, Vma12/TMEM199, Vma22/CCDC115), the metazoan accessory subunits ATP6AP1 and ATP6AP2, and the regulators of reversible V1-V0 dissociation (RAVE). synaptic_vesicle_neurotransmitter_loading references this module for its acidification step.