Renin receptor
membrane
Structures of a Complete Human V-ATPase Reveal Mechanisms of Its Assembly.
Vesicular- or vacuolar-type adenosine triphosphatases (V-ATPases) are ATP-driven proton pumps comprised of a cytoplasmic V<sub>1</sub> complex for ATP hydrolysis and a membrane-embedded V<sub>o</sub> complex for proton transfer. They play important roles in acidification of intracellular vesicles, organelles, and the extracellular milieu in eukaryotes. Here, we report cryoelectron microscopy structures of human V-ATPase in three rotational states at up to 2.9-Å resolution. Aided by mass spectrometry, we build all known protein subunits with associated N-linked glycans and identify glycolipids and phospholipids in the V<sub>o</sub> complex. We define ATP6AP1 as a structural hub for V<sub>o</sub> complex assembly because it connects to multiple V<sub>o</sub> subunits and phospholipids in the c-ring. The glycolipids and the glycosylated V<sub>o</sub> subunits form a luminal glycan coat critical for V-ATPase folding, localization, and stability. This study identifies mechanisms of V-ATPase assembly and biogenesis that rely on the integrated roles of ATP6AP1, glycans, and lipids.