ANKH : ANKH inorganic pyrophosphate transport regulator
Description
The ANKH (ANKH inorganic pyrophosphate transport regulator) is a protein-coding gene located on chromosome 5.
The ANKH gene provides instructions for making a protein that is involved in skeletal development. The ANKH protein plays a role in the development and function of cells that build bones (osteoblasts) and cells that break down bone (osteoclasts). Osteoclasts are involved in bone remodeling, a normal process in which old bone is removed and new bone is created to replace it. In addition, the ANKH protein transports a molecule called pyrophosphate out of cells to the intricate network of proteins that forms in the spaces between cells (extracellular matrix). This extracellular pyrophosphate helps regulate bone formation by preventing mineralization, the process by which minerals such as calcium and phosphorus are deposited in tissues. The ANKH protein may have other, unknown functions.
ANKH protein transports adenosine triphosphate (ATP) and potentially other nucleoside triphosphates (NTPs) from the cell's interior (cytosol) to the space outside cells (extracellular space). It primarily regulates their levels in the peripheral tissues, playing a less significant role in the entire body. ANKH prevents abnormal bone formation in the wrong places (ectopic mineralization) by managing the levels of inorganic pyrophosphate (PPi), an inhibitor of calcium and phosphate deposition. PPi is formed outside of cells from NTPs by the ENPP1 enzyme. ANKH also helps control the release of molecules used in energy production (TCA cycle intermediates) like citrate, succinate, and malate from cells. Citrate, particularly found in bone tissue, is crucial for bone-forming cells (mesenchymal stem cells) to become specialized, for the strength and stability of the bone's mineral structure (hydroxyapatite), and for overall bone strength. The exact mechanism of how ANKH moves these substances across cell membranes is not fully understood.
ANKH is also known as ANK, CCAL2, CMDJ, CPPDD, HANK, MANK, SLC62A1.
