ATP6V0B notes

2026-06-03 PN batch review

Falcon deep research was already present as ATP6V0B-deep-research-falcon.md, so
no fallback provider run was needed. I re-reviewed the existing ATP6V0B YAML in
Proteostasis PN context.

ATP6V0B is the human V-ATPase V0 proteolipid c'' subunit. The primary cloning
paper identifies hATP6F/ATP6V0B as a second human V-ATPase proteolipid and states
that it has five putative transmembrane segments and a conserved Glu98 essential
for H(+)-transporting activity PMID:9653649. The human V-ATPase structure paper
frames V-ATPase as an ATP-driven proton pump with cytoplasmic V1 ATP hydrolysis
and membrane-embedded Vo proton transfer PMID:33065002.

For PN projection, ATP6V0B appears in the Autophagy-Lysosome Pathway under V0
lysosomal v-ATPase proton pump component. The projection already matches GOA for
lysosomal lumen acidification and the broader V-type ATPase V0 domain, and it has
one conservative more-specific candidate: GO:0046610 lysosomal
proton-transporting V-type ATPase, V0 domain [file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_annotations.tsv
"ATP6V0B Autophagy-Lysosome Pathway|Pre-initiation autophagy signaling|mTORC1 pathway,
upstream|Nutrient sensing|V0 lysosomal v-ATPase proton pump component"]. I added
this as a NEW reviewed annotation because it is a component-level refinement,
not a new biological-process claim.

Conservative decisions:

• Accepted the V-ATPase component, proton transport, and organelle acidification
  annotations as core or directly supportive of core function.
• Modified broad monoatomic ion transport to proton transmembrane transport.
• Modified generic proton transmembrane transporter activity to the more
  specific complex-level rotary V-ATPase activity, while describing ATP6V0B as a
  contributor to the complex rather than an independent ATPase.
• Removed generic protein binding annotations from the GLP-1R and HuRI
  interaction screens because they do not describe ATP6V0B mechanism.
• Marked regulation of macroautophagy as over-annotation. ATP6V0B supports
  autophagic flux through lysosomal acidification, but the cited paper does not
  show a specific ATP6V0B regulatory role PMID:22982048.