Vacuolar-type H+-ATPase V0 domain (V0 domain)

The Vacuolar-type H+-ATPase (V-ATPase) V0 domain is the membrane-embedded sector of a multi-subunit enzyme that functions as an ATP-driven proton pump [3, 10]. It is responsible for the translocation of protons across biological membranes, a process essential for acidifying intracellular organelles such as lysosomes, endosomes, and the Golgi apparatus [1, 11]. This acidification is critical for various cellular processes, including protein degradation, receptor recycling, and nutrient sensing via the mTORC1 pathway [4, 11]. In specialized cells like osteoclasts, the V0 domain is targeted to the plasma membrane to facilitate bone resorption, while in cancer cells, its overexpression promotes an acidic microenvironment that favors invasion, metastasis, and drug resistance [8, 16]. The V0 domain also plays a non-canonical role in membrane fusion by interacting with SNARE proteins [5]. Pharmacological inhibitors, such as bafilomycin A1 and archazolid, target the V0 c-subunit ring to block proton transport, making the V0 domain a significant therapeutic target for osteoporosis, viral infections, and oncology [8, 13]. However, the ubiquitous nature of V-ATPases presents challenges for achieving tissue-specific inhibition and avoiding systemic toxicity [9].

Other names

V0 sectorV-ATPase V0 domainVacuolar proton-translocating ATPase V0 domainV-type H+-ATPase V0 membrane domain

Inhibition of proton translocation by binding to the proteolipid c-subunit ring of the V0 domain, which prevents the rotation of the V0 sector relative to the V1 sector and disrupts the ATP-driven proton pumping mechanism [10, 13, 15].