NOX4
Description
The NOX4 (NADPH oxidase 4) is a protein-coding gene located on chromosome 11.
NOX4 is an enzyme encoded by the NOX4 gene in humans and belongs to the NOX family of NADPH oxidases. It is crucial for oxygen sensing, which is essential for homeostasis in all aerobic organisms. NOX4 is similar to the phagocyte-type oxidase responsible for producing large amounts of reactive oxygen species (ROS) in neutrophil granulocytes, contributing to antimicrobial activity. It is proposed to function as an oxygen sensor in the kidney, regulating erythropoietin synthesis in the renal cortex. NOX4 protects the vasculature against inflammatory stress. Nox-dependent ROS modulation by amino endoperoxides can induce apoptosis in cancer cells with high NOX4 expression. Research suggests that NOX4 facilitates beneficial adaptive responses to exercise mediated by ROS. Reduced skeletal muscle NOX4 in aging and obesity contributes to insulin resistance and may promote oxidative stress.
NOX4 primarily catalyzes the reduction of oxygen to hydrogen peroxide (H2O2) but can also, to a lesser extent, reduce oxygen to superoxide. NOX4 might act as an oxygen sensor, regulating the KCNK3/TASK-1 potassium channel and HIF1A activity. It may also regulate the insulin signaling cascade and play a role in apoptosis, bone resorption, and lipolysaccharide-mediated activation of NFKB. NOX4 may produce superoxide in the nucleus and contribute to gene expression regulation upon cell stimulation.
NOX4 is also known as KOX, KOX-1, RENOX.
