Regulation of Nox and Duox enzymatic activity and expression.
In recent years, it has become clear that reactive oxygen species (ROS, which include superoxide, hydrogen peroxide, and other metabolites) are produced in biological systems. Rather than being simply a by-product of aerobic metabolism, it is now recognized that specific enzymes--the Nox (NADPH oxidase) and Duox (Dual oxidase) enzymes--seem to have the sole function of generating ROS in a carefully regulated manner, and key roles in signal transduction, immune function, hormone biosynthesis, and other normal biological functions are being uncovered. The prototypical Nox is the respiratory burst oxidase or phagocyte oxidase, which generates large amounts of superoxide and other reactive species in the phagosomes of neutrophils and macrophages, playing a central role in innate immunity by killing microbes. This enzyme system has been extensively studied over the past two decades, and provides a basis for comparison with the more recently described Nox and Duox enzymes, which generate ROS in a variety of cells and tissues. This review first considers the structure and regulation of the respiratory burst oxidase, and then reviews recent studies relating to the regulation of the activity of the novel Nox/Duox enzymes. The regulation of Nox and Duox expression in tissues and by specific stimuli is also considered here. An accompanying review considers biological and pathological roles of the Nox family of enzymes.
Lambeth
J David
JD
Department of Pathology and Laboratory Medicine, 148 Whitehead Biomedical Research Building, Emory University, 615 Michael Street, Atlanta, GA 30322, USA. noxdoc@mac.com
Kawahara
Tsukasa
T
Diebold
Becky
B
D000818:Animals; D000074623:Dual Oxidases; D005420:Flavoproteins / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D000074624:NADPH Oxidase 1; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D000074664:NADPH Oxidase 5; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D010586:Phagocytes / Q000502:physiology*; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000502:physiology; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000378:metabolism
D005420:Flavoproteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010750:Phosphoproteins; D021122:Protein Subunits; C079789:neutrophil cytosol factor 67K; D000074623:Dual Oxidases; C056558:CYBB protein, human; D000074624:NADPH Oxidase 1; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D000074664:NADPH Oxidase 5; D019255:NADPH Oxidases; C402799:NOX1 protein, human; C431571:NOX5 protein, human; C422943:Nox4 protein, mouse; C431513:DUOX1 protein, human; C060505:neutrophil cytosolic factor 1; C022709:superoxide-forming enzyme