Scientific article

A Ca(2+)-activated NADPH oxidase in testis, spleen, and lymph nodes

Published inThe Journal of biological chemistry, vol. 276, no. 40, p. 37594-37601
Publication date2001

Superoxide and its derivatives are increasingly implicated in the regulation of physiological functions from oxygen sensing and blood pressure regulation to lymphocyte activation and sperm-oocyte fusion. Here we describe a novel superoxide-generating NADPH oxidase referred to as NADPH oxidase 5 (NOX5). NOX5 is distantly related to the gp91(phox) subunit of the phagocyte NADPH oxidase with conserved regions crucial for the electron transport (NADPH, FAD and heme binding sites). However, NOX5 has a unique N-terminal extension that contains three EF hand motifs. The mRNA of NOX5 is expressed in pachytene spermatocytes of testis and in B- and T-lymphocyte-rich areas of spleen and lymph nodes. When heterologously expressed, NOX5 was quiescent in unstimulated cells. However, in response to elevations of the cytosolic Ca(2+) concentration it generated large amounts of superoxide. Upon Ca(2+) activation, NOX5 also displayed a second function: it became a proton channel, presumably to compensate charge and pH alterations due to electron export. In summary, we have identified a novel NADPH oxidase that generates superoxide and functions as a H(+) channel in a Ca(2+)-dependent manner. NOX5 is likely to be involved in Ca(2+)-activated, redox-dependent processes of spermatozoa and lymphocytes such as sperm-oocyte fusion, cell proliferation, and cytokine secretion.

  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Calcium/ metabolism/physiology
  • Cytosol/metabolism
  • Electrophysiology
  • Genome
  • Hela Cells
  • Humans
  • In Situ Hybridization
  • Ion Transport
  • Lymph Nodes/ enzymology
  • Male
  • Membrane Proteins/genetics/ metabolism/physiology
  • Molecular Sequence Data
  • NADPH Oxidase/chemistry/genetics/ metabolism/physiology
  • Polymerase Chain Reaction
  • Protons
  • Sequence Homology, Amino Acid
  • Spleen/ enzymology
  • Superoxides/metabolism
  • Testis/ enzymology
Citation (ISO format)
BANFI, Botond et al. A Ca(2+)-activated NADPH oxidase in testis, spleen, and lymph nodes. In: The Journal of biological chemistry, 2001, vol. 276, n° 40, p. 37594–37601. doi: 10.1074/jbc.M103034200
Updates (1)
ISSN of the journal0021-9258

Technical informations

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