V-type proton ATPase subunit C1 (ATP6V1C1)

V-type proton ATPase subunit C1 (ATP6V1C1) is a key component of the vacuolar-type H^(+)-ATPase (V-ATPase) complex, an ATP-dependent proton pump responsible for acidifying a variety of intracellular compartments in eukaryotic cells, including endosomes, lysosomes, and secretory vesicles[2][3][4]. It is encoded by the ATP6V1C1 gene on chromosome 8 and belongs to the V1 domain of V-ATPase, which contains the catalytic ATP-hydrolyzing site and subunits essential for energy transduction. The C1 subunit is directly involved in regulating V-ATPase assembly, controlling the reversible dissociation of the peripheral V1 and membrane-integral V0 sectors—a key mechanism in modulating pump function in response to cellular signals[2]. ATP6V1C1 is ubiquitously expressed but especially critical in osteoclasts, where it supports extracellular acidification necessary for bone resorption[1]. Inhibition or deficiency of ATP6V1C1 impairs proton transport and acidification processes, resulting in disrupted vesicular trafficking, protein degradation, and cellular signaling, and is implicated in pathologies such as impaired bone remodeling, cancer, and neurodegenerative diseases[1][2][3][4]. Drugs such as bafilomycin A1 and concanamycin inhibit V-ATPase by targeting this or closely related subunits, affecting vescicular pH homeostasis and cellular metabolism.

Other names

ATP6CATP6DVATCVma5Vacuolar proton pump subunit C1H(+)-transporting ATPase chain CV-ATPase C subunitV-ATPase subunit C1Vacuolar ATP synthase subunit CEC 3.6.3.14FLJ20057

Inhibition of proton translocation across organelle/plasma membrane (disrupts acidification) Blockade of lysosomal acidification (impairs autophagy, protein degradation)