Regulation of superoxide-producing NADPH oxidases in nonphagocytic cells.
The membrane-integrated protein gp91phox functions as the catalytic center of the superoxide-producing phagocyte NADPH oxidase. Recent studies have identified homologs of gp91phox in nonphagocytic cells, which constitute the NADPH oxidase (Nox) family. Activation of the Nox oxidases leads to production of reactive oxygen species (ROS), thereby participating in a variety of biological events, such as host defense, hormone biosynthesis, and signal transduction. The activity of the Nox enzymes is regulated by various proteins, including the small GTPase Rac; regulatory mechanisms differ dependent on the type of the Nox proteins. For example, an oxidase activator (p47phox or Noxo1) and an oxidase activator (p67phox or Noxa1) are absolutely required for superoxide production by gp91phox and Nox1, but not by Nox3. Rac, albeit probably dispensable to the Nox3 activity, plays an essential role in activation of gp91phox. Thus, functional reconstitution of Nox systems is crucial for the study of Nox regulation. Here we describe a basic method for the reconstitution of Nox systems by expression of oxidase proteins in transfectable cells.
Medical Institute of Bioregulation, Kyushu University, Fuku-oka, Japan.
Ryu
R
Takeya
Noriko
N
Ueno
Hideki
H
Sumimoto
D000818:Animals; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D000074623:Dual Oxidases; D005420:Flavoproteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D000074624:NADPH Oxidase 1; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000378:metabolism*; D010586:Phagocytes / Q000201:enzymology; D013481:Superoxides / Q000378:metabolism; D014162:Transfection
D005420:Flavoproteins; D008565:Membrane Proteins; D013481:Superoxides; D000074623:Dual Oxidases; D000074624:NADPH Oxidase 1; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C402799:NOX1 protein, human; C498910:NOX4 protein, human; C431570:Nox3 protein, human; C431513:DUOX1 protein, human; C431515:DUOX2 protein, human; C022709:superoxide-forming enzyme