The integral membrane protein p22 phox forms a heterodimeric enzyme complex with
NADPH oxidases (Noxs) and is required for their catalytic activity. Nox4, a Nox linked to
cardiovascular disease, angiogenesis, and insulin signaling, is unique in its ability to
produce hydrogen peroxide constitutively. To date, p22 phox constitutes the only identified
regulatory component for Nox4 function. To delineate structural elements in p22 phox
essential for formation and localization of the Nox4-p22 phox complex and its enzymatic …