KLHL3 : kelch like family member 3
Description
The KLHL3 (kelch like family member 3) is a protein-coding gene located on chromosome 5.
The KLHL3 gene provides instructions for making a protein that plays a role in the cell machinery that breaks down (degrades) unwanted proteins, called the ubiquitin-proteasome system. The KLHL3 protein is one 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. The KLHL3 protein identifies the target of the E3 ubiquitin ligase complex and attaches the complex to it. Complexes containing the KLHL3 protein tag proteins called WNK1 and WNK4 with ubiquitin. The WNK1 and WNK4 proteins are involved in controlling blood pressure in the body. By regulating the amount of these proteins available, KLHL3 plays a role in blood pressure control.
KLHL3 is a substrate-specific adapter of a BCR (BTB-CUL3-RBX1) E3 ubiquitin ligase complex that acts as a regulator of ion transport in the distal nephron. The BCR(KLHL3) complex mediates ubiquitination and degradation of WNK1 and WNK4, two activators of Na-Cl cotransporter SLC12A3/NCC in distal convoluted tubule cells of kidney, thereby regulating NaCl reabsorption. The BCR(KLHL3) complex also mediates ubiquitination and degradation of WNK3. Additionally, the BCR(KLHL3) complex mediates ubiquitination of CLDN8, a tight-junction protein required for paracellular chloride transport in the kidney, leading to its degradation.
KLHL3 is also known as PHA2D.
