Nicotinamide Adenine Dinucleotide Phosphate Oxidase 5 (NOX5)

NOX5 is distantly related to the gp91-phox subunit of the phagocyte NADPH oxidase with conserved regions crucial for electron transport (NADPH, FAD, and heme binding sites). However, NOX5 has a unique N-terminal extension that contains 3 EF-hand motifs. Banfi et al. (2001) demonstrated 2 NOX5 isoforms of 737 and 719 amino acids, designated NOX5A and NOX5B, respectively. Northern blot analysis demonstrated restricted expression of an approximately 2.7-kb NOX5A transcript in spleen and an approximately 2.9-kb NOX5B transcript in testis. In situ hybridization localized NOX5 in pachytene spermatocytes of testis and in B- and T-lymphocytic-rich areas of spleen and lymph nodes.