What is the function of V ATPase?

V-ATPases are proton pumps that function to acidify intracellular compartments in all eukaryotic cells, and to transport protons across the plasma membrane of certain specialized cells.

Where is ATPase found?

* F-ATPases (ATP synthases, F1F0-ATPases), which are found in mitochondria, chloroplasts and bacterial plasma membranes where they are the prime producers of ATP, using the proton gradient generated by oxidative phosphorylation (mitochondria) or photosynthesis (chloroplasts).

What does the V type ATPase in the plant vacuole do?

At the plant vacuole the V-ATPase is responsible for energization of transport of ions and metabolites, and thus the V-ATPase is important as a ‘house-keeping’ and as a stress response enzyme.

What is ATPase mention its parts role and functioning?

The ATP synthase of mitochondria and chloroplasts is an anabolic enzyme that harnesses the energy of a transmembrane proton gradient as an energy source for adding an inorganic phosphate group to a molecule of adenosine diphosphate (ADP) to form a molecule of adenosine triphosphate (ATP).

What is the example of V ATPase?

V-ATPases are also found in the plasma membranes of a wide variety of cells such as intercalated cells of the kidney, osteoclasts (bone resorbing cells), macrophages, neutrophils, sperm, midgut cells of insects, and certain tumor cells.

What is an ATPase activity?

Overview. The term ATPase applies to the activity of any enzyme’s ability to decompose ATP, including metabolic enzymes involved in anabolic processes that need energy, as well as enzymes promoting transport across membrane. This process of ATP synthesis is often called oxidative phosphorylation.

What activates ATPase?

The activation mechanism of the enzyme is well known and involves phosphorylation of its penultimate residue, a threonine, by an as yet unidentified protein kinase; phosphorylation in turn leads to the binding of regulatory 14-3-3 protein dimers and to the formation of an activated complex consisting of six H+-ATPases …

What kind of protein is ATPase?

1.1 Overall Architecture. The P-type ATPases are a large family of integral membrane proteins that use the energy of ATP hydrolysis to transport cations and lipids across membranes (Bublitz, Morth, & Nissen, 2011; Palmgren & Nissen, 2011).

Why do vacuoles have low pH?

The extremely low pH is due to the accumulation of H2SO4. In principle, the two proton pumps on the tonoplast can regulate cytosolic pH by pumping massive amounts of protons out of the cytosol into the lumen of the vacuole, although this has been difficult to demonstrate directly (Moriyasu et al. 1984).

What enzyme synthesizes ATP?

ATP synthase is the very last enzyme in oxidative phosphorylation pathway that makes use of electrochemical energy to power ATP synthesis [7, 8, 9, 10]. ATP synthase is one of the most ubiquitous and plentiful protein on the earth, accountable for the reversible catalysis of ATP to ADP and Pi.

How do you test ATPase activity?

Calculate the ATPase activity for each sample by calibrating with the phosphate standard. Phosphate released = (OD650 – Y intercept)/slope. Average the total Pi from duplicates of each sample. Subtract the buffer-only control’s absorbance reading from this number.

Which is an example of the function of V-ATPase?

For example, the proton gradient across the yeast vacuolar membrane generated by V-ATPases drives calcium uptake into the vacuole through an H+ /Ca2+ antiporter system. In synaptic transmission in neuronal cells, V-ATPase acidifies synaptic vesicles. Norepinephrine enters vesicles by V-ATPase.

How are the rotor axles of the V-ATPase linked?

These structures have revealed that the V-ATPase has a 3-stator network, linked by a collar of density formed by the C, H, and a subunits, which, while dividing the V 1 and V o domains, make no interactions with the central rotor axle formed by the F, D, and d subunits.

Which is responsible for proton translocation in the V-ATPase?

The V o domain is responsible for proton translocation. Opposite the F-type ATP synthase, the V o domain is transporting protons against their own concentration gradient. Rotation of the V o domain transports the protons in movement coordinated with the V 1 domain, which is responsible for ATP hydrolysis.

What happens when subunit C is released from the ATPase complex?

The release of subunit C from the ATPase complex results in the dissociation of the V1 and V0 subcomplexes, which is an important mechanism in controlling V-ATPase activity in cells. Essentially, by creating a high electrochemical gradient and low pH, this powers the enzyme to create more ATP.