Vacuolar ATPases are proton pumps that are dependent on ATP. They are involved with processes along the plasma membrane. The processes involved are membrane traffic, protein degradation, bone resorption, tumor cell invasion, and pH homeostasis. There has been a better understanding of the structure and mechanism of V-ATPases. Another thing brought to light, are the mechanisms that occur to regulate its activity in cells. This includes the V¬1 and V0 domain assembly and the regulation of the V-ATPases. The final section of the journal focuses on emerging functions which includes its involvement in cancer and cell signaling.
V-ATPases are proton pumps present within …show more content…
Some of these cells include osteoclasts, renal intercalated cells, and epididymal clear cells. Osteoclasts are large multinucleate cells that are involved in bone formation and also the remodeling of bone. Renal intercalated cells participate in acid-base homeostasis. Epididymal clear cells are part of the epididymis. An epididymis is a tube that connects a testicle to a vas deferens in the male reproductive system. Within the epididymis, there are several types of cells that make up the epithelium, some of which are the main, basal, apical, clear, intraepithelial lymphocytes, and intraepithelial macrophages. Clear cells are predominant in the tail region of the epithelium. The ways in which these cells are involved with V-ATPases are as follows. Osteoclasts use plasma membrane V-ATPases to acidify the extracellular space between the bone and cell. This is vital for the resorption of bone. In the kidneys, the protein at the apical membrane of the alpha cells produce acid into the renal tubule; this causes the pH of the cell to …show more content…
These domains are the cytosolic V¬1 and the integral V0. Within the first area (V1), there are eight subunits, A-H; this is mainly responsible for the hydrolysis of ATP. V0 carries out proton transport. This domain includes subunits a, d, e, c, and c’’. In yeast, there is an additional subunit, c’, and in more complex eukaryotes there is an accessory protein known as Ac45. One of the important features of the V-ATPase is that it operates with a rotary mechanism to drive proton transport across the membrane of the cell. This is driven by ATP hydrolysis at the nucleotide binding site (subunit A) thus causing the rotation of the central stalk (subunits D and