ANG

The ANG gene provides instructions for making a protein called angiogenin. This protein promotes the formation of new blood vessels from pre-existing blood vessels through a process called angiogenesis. In this process, angiogenin helps stimulate the growth and division of endothelial cells, which line the inside surface of blood vessels, to form new blood vessels. Angiogenesis is important for restoring blood flow after an injury. Angiogenin may also be involved in other steps of angiogenesis, such as helping to break down the tissue that surrounds existing blood vessels to allow room for the growth of new blood vessels.

Angiogenin is found in a variety of cells throughout the body and circulates in the bloodstream. When angiogenin attaches (binds) to receptors on the surface of endothelial cells, it triggers a series of reactions that bring angiogenin inside the cell. Once inside endothelial cells, angiogenin moves to the nucleus where it plays a role in regulating protein production. To stimulate the production of proteins, angiogenin triggers the production of ribosomal RNA (rRNA), a chemical cousin of DNA. Ribosomal RNA is required for assembling protein building blocks (amino acids) into functioning proteins. Angiogenin triggers the production of rRNA when there is an increased demand for proteins, such as for the growth and division of endothelial cells. When proteins are not needed, angiogenin breaks down a form of RNA called transfer RNA (tRNA), which, along with rRNA, is needed for assembling amino acids into full-length, functioning proteins.

Research findings suggest that angiogenin also has antimicrobial properties, which means it can help fight infections caused by bacteria and fungi.

amyotrophic lateral sclerosis - increased risk from variations of the ANG gene

Researchers have identified several ANG gene mutations that may increase the risk of developing amyotrophic lateral sclerosis (ALS), a condition characterized by progressive movement problems and muscle wasting. These mutations change single amino acids in the angiogenin protein. The effect of ANG gene mutations is not fully understood. Researchers suggest that most mutations reduce the activity of angiogenin. It is thought that a reduction in angiogenin's ability to promote the production of rRNA and subsequently the production of proteins has a negative effect on cells, which may cause them eventually to die. It is unclear how this cell death impacts the nerve cells that are affected in ALS. Some people with ANG gene mutations who develop ALS also develop a condition called frontotemporal dementia (FTD), which is a progressive brain disorder that affects personality, behavior, and language. Individuals who develop both conditions are diagnosed as having ALS-FTD. It is unknown why some people with ALS develop FTD and others do not.