UBA gene family

Genes in the UBA gene family provide instructions for making proteins called ubiquitin-like modifier activating enzymes. The enzymes, also called E1s, turn on (activate) ubiquitin-like proteins. Ubiquitin-like proteins attach (bind) to other proteins and can affect these proteins’ activity, interactions with other proteins, and locations within the cell. The activation of ubiquitin-like proteins influences a wide range of body processes, from immune system responses to prenatal development.

The E1 enzymes activate ubiquitin-like proteins in a process called the conjugation cascade. The conjugation cascade begins when an E1 binds to a ubiquitin-like protein, causing it to become active. In subsequent steps, the activated protein is passed between many enzymes until it reaches its target protein and can carry out its specific function. Different E1s activate different ubiquitin-like proteins.

A particular UBA gene, UBA1, activates the protein ubiquitin. Ubiquitin attaches to proteins that need to be broken down (degraded). Cellular structures called proteasomes recognize and degrade proteins tagged with ubiquitin. The ubiquitin-proteasome system acts as the cell's quality control system by disposing of damaged, misshapen, and excess proteins. Protein degradation is a normal process that removes damaged or unnecessary proteins and helps maintain the normal functions of cells. This system also regulates the level of proteins involved in several critical cell activities such as the timing of cell division and growth. The activation of ubiquitin initiates the ubiquitin-proteasome system.

A few diseases have been found to be caused by mutations in UBA genes. One example is X-linked spinal muscular atrophy, a condition that affects the control of muscle movement, which is caused by mutations in the UBA1 gene.