Luteolin inhibition of V-ATPase a3-d2 interaction decreases osteoclast resorptive activity.

V-ATPase-mediated acid secretion is required for osteoclast bone resorption. Osteoclasts are enriched in V-ATPase a3 and d2 subunit isoforms, and disruption of either of their genes impairs bone resorption. Using purified fusion proteins of a3 N-terminal domain (NTa3) and full-length d subunits we determined in a solid-phase binding assay that half-maximal binding of d1 or d2 to immobilized NTa3 occurs at 3.