Molecular Characterization and Localization of the NAD(P)H Oxidase Components gp91-phox and p22-phox in Endothelial Cells

Bayraktutan, Ulvi; Blayney, Lynda; Shah, Ajay

Abstract

The production of reactive oxygen species (ROS) within endothelial cells may have several effects, including
alterations in the activity of paracrine factors, gene expression, apoptosis, and cellular injury. Recent studies indicate that
a phagocyte-type NAD(P)H oxidase is a major source of endothelial ROS. In contrast to the high-output phagocytic
oxidase, the endothelial enzyme has much lower biochemical activity and a different substrate specificity
(NADH.NADPH). In the present study, we (1) cloned and characterized the cDNA and predicted amino acid structures
of the 2 major subunits of rat coronary microvascular endothelial cell NAD(P)H oxidase, gp91-phox and p22-phox;
(2) undertook a detailed comparison with phagocytic NADPH oxidase sequences; and (3) studied the subcellular
location of these subunits in endothelial cells. Although these studies revealed an overall high degree of homology
(.90%) between the endothelial and phagocytic oxidase subunits, the endothelial gp91-phox sequence has potentially
important differences in a putative NADPH-binding domain and in putative glycosylation sites. In addition, the
subcellular location of the endothelial gp91-phox and p22-phox subunits is significantly different from that reported for
the neutrophil oxidase, in that they are predominantly intracellular and collocated in the vicinity of the endoplasmic
reticulum. This first detailed characterization of gp91-phox and p22-phox structure and location in endothelial cells
provides new data that may account, in part, for the differences in function between the phagocytic and endothelial
NAD(P)H oxidases.

Citation

Bayraktutan, U., Blayney, L., & Shah, A. (2000). Molecular Characterization and Localization of the NAD(P)H Oxidase Components gp91-phox and p22-phox in Endothelial Cells

• Journal Article Type: Article
• Publication Date: Jan 1, 2000
• Deposit Date: Oct 26, 2006
• Publicly Available Date: Aug 22, 2008
• Journal: Arteriosclerosis thrombosis and vascular biology
• Publisher: American Heart Association
• Peer Reviewed: Peer Reviewed
• Volume: 20
• Keywords: endothelium n NADPH oxidase n reactive oxygen species n cDNA
• Public URL: https://nottingham-repository.worktribe.com/output/1023593
• Related Public URLs: http://atvb.ahajournals.org/