CUL3 Gene

The CUL3 gene provides instructions for making a protein called cullin-3. This protein plays a role in the cell machinery that breaks down (degrades) unwanted proteins, called the ubiquitin-proteasome system.

Cullin-3 is a core piece of a complex known as an E3 ubiquitin ligase. E3 ubiquitin ligases function as part of the ubiquitin-proteasome system by tagging damaged and excess proteins with molecules called ubiquitin. Ubiquitin serves as a signal to specialized cell structures known as proteasomes, which attach (bind) to the tagged proteins and degrade them. The ubiquitin-proteasome system acts as the cell's quality control system by disposing of damaged, misshapen, and excess proteins. This system also regulates the level of proteins involved in several critical cell activities such as the timing of cell division and growth.

E3 ubiquitin ligases containing the cullin-3 protein tag proteins called WNK1 and WNK4 with ubiquitin. These proteins are involved in controlling blood pressure in the body. By regulating the amount of WNK1 and WNK4 available, cullin-3 plays a role in blood pressure control.