ATP6V1H encodes subunit H of the vacuolar H+-ATPase (V-ATPase), a multisubunit proton pump essential for intracellular acidification 1. As a component of the V1 catalytic complex, ATP6V1H is required for V-ATPase activity but not assembly, and is critical for maintaining acidic pH in lysosomes, endosomes, and Golgi compartments 2. ATP6V1H serves as a cellular damage sensor by directly binding ATG16L1 within fully assembled V-ATPases to recruit autophagy machinery following proton gradient dissipation, particularly during pathogenic infections and immune activation 3. Transcriptionally, ATP6V1H is regulated by TFEB through CLEAR sequences, linking lysosomal biogenesis to immune responses in tauopathy 1. Clinically, ATP6V1H deficiency causes osteoporosis through multiple mechanisms: elevated MMP9/MMP13 expression impairs bone mineralization 4, reduced TGF-β signaling decreases osteogenic differentiation of bone marrow stromal cells 5, and dysregulated osteoclastic acidification is implicated in bone loss 6. Additionally, ATP6V1H deficiency impairs glucose tolerance by augmenting endoplasmic reticulum stress in pancreatic β-cells, increasing type 2 diabetes susceptibility 7. Long noncoding RNA lnc-TCEA1-3 regulates ATP6V1H expression and osteoclast function, identifying potential therapeutic targets for bone disease 6.