Nox Organizing protein 1 (NoxO1) is a critical regulator of enzyme kinetics of the nonphagocytic NADPH oxidase Nox1, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide []. NoxO1 is involved in targeting activator subunits (such as NoxA1) to Nox1. It is co-localized with Nox1 in the membranes of resting cells and directs the subcellular localization of Nox1 []. NoxO1 contains an N-terminal Phox homology (PX) domain, tandem SH3 domains (N-SH3 and C-SH3), and a C-terminal proline-rich region (PRR).This entry represents the second SH3 domain (or C-SH3) of NoxO1. The tandem SH3 domains of NoxO1 interact with the PRR of p22phox, which also complexes with Nox1 [].
ADPH oxidase 1 (NOX1) is a NADPH oxidase that generates superoxide []. It is involved in several cell functions such as proliferation, vascular contraction, host defence, and cytoskeletal remodelling []. It requires small GTPase Rac, Noxa1 and Noxo1 for its activation []. It can be regulated by betaPix through Rac activation [].
NADPH oxidase activator 1 (NOXA1), also known as p51-nox or p67phox-like factor, functions as an activator of NOX1 and NOX2, members of the Nox family of superoxide-producing NADPH oxidases []. It is homologous to the component p67-phox of the phagocytic oxidase, the prototypical Nox [, ]. NOXA1 and NOXO1 support superoxide generation by NOX1 and are expressed predominantly in colon epithelium with NOX1 []. NOXA1 is also coexpressed with NOX2 in some cells, such as endothelial cells, vascular smooth muscle cells, and hematopoietic stem cells [].
