Format

Send to

Choose Destination
Arch Biochem Biophys. 2010 Sep 1;501(1):116-23. doi: 10.1016/j.abb.2010.03.019. Epub 2010 Mar 31.

NAD(P)H:quinone acceptor oxidoreductase 1 (NQO1), a multifunctional antioxidant enzyme and exceptionally versatile cytoprotector.

Author information

1
Biomedical Research Institute, University of Dundee, Dundee, Scotland, UK.

Abstract

NAD(P)H:quinone acceptor oxidoreductase 1 (NQO1) is a widely-distributed FAD-dependent flavoprotein that promotes obligatory 2-electron reductions of quinones, quinoneimines, nitroaromatics, and azo dyes, at rates that are comparable with NADH or NADPH. These reductions depress quinone levels and thereby minimize opportunities for generation of reactive oxygen intermediates by redox cycling, and for depletion of intracellular thiol pools. NQO1 is a highly-inducible enzyme that is regulated by the Keap1/Nrf2/ARE pathway. Evidence for the importance of the antioxidant functions of NQO1 in combating oxidative stress is provided by demonstrations that induction of NQO1 levels or their depletion (knockout, or knockdown) are associated with decreased and increased susceptibilities to oxidative stress, respectively. Furthermore, benzene genotoxicity is markedly enhanced when NQO1 activity is compromised. Not surprisingly, human polymorphisms that suppress NQO1 activities are associated with increased predisposition to disease. Recent studies have uncovered protective roles for NQO1 that apparently are unrelated to its enzymatic activities. NQO1 binds to and thereby stabilizes the important tumor suppressor p53 against proteasomal degradation. Indeed, NQO1 appears to regulate the degradative fate of other proteins. These findings suggest that NQO1 may exercise a selective "gatekeeping" role in regulating the proteasomal degradation of specific proteins, thereby broadening the cytoprotective role of NQO1 far beyond its highly effective antioxidant functions.

PMID:
20361926
PMCID:
PMC2930038
DOI:
10.1016/j.abb.2010.03.019
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center