V-type proton ATPase 116 kDa subunit a3 (TCIRG1)

V-type proton ATPase 116 kDa subunit a3 (TCIRG1) is an essential membrane protein acting as the a3 subunit within the larger vacuolar H+-ATPase (V-ATPase) complex. V-ATPases are responsible for pumping protons across intracellular and extracellular membranes, regulating pH and acidifying vesicular compartments. The a3 subunit is particularly critical in osteoclasts, where it creates an acidic environment necessary for bone matrix dissolution and normal bone remodeling. TCIRG1’s variant TIRC7, arising by alternative splicing, plays a distinct role as a regulator in T cells, mediating immune response and cell apoptosis via interaction with HLA-DRα2. Mutations in TCIRG1 are directly linked to severe infantile osteopetrosis and have been implicated in immune dysregulation. Due to its central roles, the target is of interest in bone resorption disorders and potentially in immune-related therapeutic strategies.

Other names

T cell immune regulator 1ATPase H+ transporting V0 subunit a3a3Atp6iATP6N1CATP6V0A3OC-116OC116TIRC7

Inhibition of proton transport—blocking acidification in vesicles or extracellular spaces, leading to failure of bone resorption or altered cellular homeostasis