proton-transporting V-type ATPase complex

Definition

Target type: cellularcomponent

A proton-transporting two-sector ATPase complex that couples ATP hydrolysis to the transport of protons across a concentration gradient. The resulting transmembrane electrochemical potential of H+ is used to drive a variety of (i) secondary active transport systems via H+-dependent symporters and antiporters and (ii) channel-mediated transport systems. The complex comprises a membrane sector (V0) that carries out proton transport and a cytoplasmic compartment sector (V1) that catalyzes ATP hydrolysis. V-type ATPases are found in the membranes of organelles such as vacuoles, endosomes, and lysosomes, and in the plasma membrane. [GOC:mah, ISBN:0716743663, PMID:16449553]

The proton-transporting V-type ATPase complex is a multi-subunit enzyme that is responsible for acidifying intracellular compartments in eukaryotes. This complex is found in a variety of organelles, including lysosomes, endosomes, vacuoles, and Golgi. The complex is composed of two main domains: the V1 domain, which is responsible for ATP hydrolysis, and the V0 domain, which is responsible for proton translocation.

The V1 domain is located in the cytoplasm and consists of eight subunits: A, B, C, D, E, F, G, and H. The A and B subunits are catalytic subunits that bind ATP and hydrolyze it to ADP and inorganic phosphate. The C, D, E, and F subunits are regulatory subunits that are involved in controlling the activity of the complex. The G and H subunits are involved in the assembly and stability of the V1 domain.

The V0 domain is embedded in the membrane and consists of five subunits: a, b, c, d, and e. The a subunit is a transmembrane protein that forms the proton channel. The b and c subunits are also transmembrane proteins and are involved in the assembly and stability of the V0 domain. The d and e subunits are peripheral membrane proteins that are associated with the a subunit.

The proton-transporting V-type ATPase complex works by using the energy released from ATP hydrolysis to pump protons from the cytoplasm into the lumen of the organelle. This proton gradient is then used to drive a variety of cellular processes, including the transport of nutrients, the activation of enzymes, and the maintenance of pH homeostasis.

The cellular component of the V-type ATPase complex is highly complex and is composed of multiple subunits that interact with each other in a specific way. The subunits of the V-type ATPase complex are encoded by a number of different genes, and mutations in these genes can lead to a variety of human diseases.

For example, mutations in the ATP6V1A gene, which encodes the A subunit of the V1 domain, have been linked to a number of human diseases, including osteopetrosis, a bone disease characterized by increased bone density. Mutations in the ATP6V0A2 gene, which encodes the a subunit of the V0 domain, have been linked to deafness and kidney disease.'
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Proteins (1)

Compounds (1)