Cytoplasmic terminus of vacuolar type proton pump accessory subunit Ac45 is required for proper interaction with V(0) domain subunits and efficient osteoclastic bone resorption.

ABSTRACT: Solubilization of mineralized bone by osteoclasts is largely dependent on the acidification of the extracellular resorption lacuna driven by the vacuolar (H+)-ATPases (V-ATPases) polarized within the ruffled border membranes. V-ATPases consist of two functionally and structurally distinct domains, V(1) and V(0). The peripheral cytoplasmically oriented V(1) domain drives ATP hydrolysis, which necessitates the translocation of protons across the integral membrane bound V(0) domain. Here, we demonstrate that an accessory subunit, Ac45, interacts with the V(0) domain and contributes to the vacuolar type proton pump-mediated function in osteoclasts. Consistent with its role in intracellular acidification, Ac45 was found to be localized to the ruffled border region of polarized resorbing osteocl

SUBMITTER: Feng H 

PROVIDER: S-EPMC2442344 | biostudies-literature | 2008 May

REPOSITORIES: biostudies-literature