ATP gene family

Genes in the ATP gene family provide instructions for making transporter proteins called ATPases. The ATP gene family is made up of a variety of ATPases, which is why it is frequently called the ATPase superfamily. ATPases carry many types of molecules, such as fats, sugars, protein building blocks (amino acids), charged atoms or molecules (ions), and drugs, across cell membranes. In most cases, the transporters move the molecules into specific cell compartments so they can be processed, or out of the cell so they can be used elsewhere or excreted from the body. If the molecules are not transported properly, they may be unavailable where they are needed for body functions. The molecules can also build up over time and damage the cells.

ATPases are made in many tissues of the body, where they use energy from a molecule called ATP to move substances across the cell membranes. They are grouped together because they all have common regions (domains) that bind to ATP. Most ATPases break down ATP to provide energy for molecule transport.

The ATPase gene family is called a superfamily because all the members have related structures or functions. Within this superfamily are four subfamilies that are distinguished by their location within the cell and how they transport molecules. The P-type of ATPases transport ions such as calcium, potassium, sodium, copper, and hydrogen into and out of the cell. The movement of these ions into and out of cells controls many functions such as muscle movement and protein production. The F-types are located on the membranes of the energy-producing centers within cells (mitochondria), and instead of breaking down ATP to transport molecules, these ATPases make ATP. Because the F-type ATPases produce ATP, they are called ATP synthases. The V-types are located on the membranes of compartments in the cell that digest and recycle materials (lysosomes), where they transport hydrogen ions. Through this action, these ATPases play a role in moving proteins between cells, releasing chemical messengers (neurotransmitters), and a variety of other cell functions. The ATP-binding cassette (ABC) types are located on the cell membrane and transport a variety of molecules, fats, sugars, and proteins into and out of the cell. These substances are needed for proper cell functioning.

Most of the genes in this family are designated by the letters ATP and an additional number and a letter indicating the subgroup to which they belong. The subgroup designation is based on their structure and similarity to other transporters in the gene family. They also receive a number to designate the specific gene within the subgroup. For example, ATP2A2 is gene 2 in the 2A subgroup of ATPases. Some proteins in this superfamily are named according to their subfamily grouping, for example ABCD1.