Renal acid elimination depends on the combined action of the ammonia (NH₃) transporter Rhcg and proton pumps (H⁺-ATPases). B1 H⁺-ATPase genetic mutation or ablation causes distal renal tubular acidosis (dRTA) with lower ammonium (NH₄⁺) excretion while an incomplete form of dRTA is also found in Rhcg^-/- mice. Here we examined the interaction between Rhcg and H⁺-ATPase in renal acid handling. Metabolic studies revealed higher urinary pH and lower urinary NH₄⁺excretion for both Rhcg^-/- and B1^-/- acid-loaded mice. In vitro, reduced NH₃ transport in microperfused Rhcg^-/- collecting ducts was associated with decreased H⁺ fluxes. Vice versa, pharmacological inhibition of H⁺-ATPases in Rhcg^+/+ resulted in decreased H⁺ transport and reduced NH₃ permeability. Rhcg mRNA level appeared furthermore lower in B1^-/- than ^+/+ mice and we found decrease B2 H⁺-ATPase protein level in Rhcg^-/- compared to ^+/+ . In addition, HEK293 cells overexpressing RhCG showed higher levels of B1 H⁺-ATPase mRNA and elevated H⁺ excretion rates compared to mock transfected cells. Ongoing experiments of RhCG pull-down and shotgun proteomics aim to identify RhCG interacting partners and to test for co-immunoprecipitation of H⁺-ATPase subunits. Thus, Rhcg and H⁺-ATPases may interact, directly or indirectly, to eliminate in parallel NH₃ and H⁺ into urine.