Abstract
NAD(P)H:quinone oxidoreductase 1 (NQO1) is a flavoenzyme that catalyzes two-electron reductive metabolism and detoxification of quinones and their derivatives leading to protection of cells against redox cycling and oxidative stress. To examine the in vivo role of NQO1, a NQO1-null mouse was produced using targeted gene disruption. Mice lacking NQO1 gene expression showed no detectable phenotype and were indistinguishable from wild-type mice. However, NQO1-null mice exhibited increased toxicity when administered menadione compared with wild-type mice. These results establish a role for NQO1 in protection against quinone toxicity. The NQO1-null mice are a model for NQO1 deficiency in humans and can be used to determine the role of this enzyme in sensitivity to toxicity and carcinogenesis.
Highlights
NAD(P)H:quinone oxidoreductase 1 (NQO1) is a flavoenzyme that catalyzes two-electron reductive metabolism and detoxification of quinones and their derivatives leading to protection of cells against redox cycling and oxidative stress
Several lines of evidence indicate that modification of the NQO1 gene by replacing exon 6 with the neo-cassette resulted in a null mutation
NQO1 mRNA and protein were not detected in NQO1Ϫ/Ϫ mice
Summary
Isolation and Characterization of Mouse NQO1 Gene—A full-length rat NQO1 cDNA was used to screen a 129SVJ mouse genomic library from Stratagene (La Jolla, CA) by procedures described previously [19]. The plasmid pUC19-mNQO1 gene (SalI-SalI) was digested with BamHI to remove 2.0 kb of the mouse NQO1 gene containing a portion of intron 5, exon 6, and a small portion of the 3Ј-flanking region. The 7.0 kb of the SalI-SalI fragment from the NQO1 gene containing 2.0 kb of the neo-cassette instead of exon 6 of the mNQO1 gene was isolated and subcloned at the SalI site of the pMC1tk-pA plasmid to generate the targeting vector pPNT-mouse NQO1 gene (Fig. 1). The DNAs from wild-type (NQO1ϩ/ϩ), heterozygous (NQO1ϩ/Ϫ), and NQO1Ϫ/Ϫ mice were digested with BamHI, run on agarose gel, blotted, and hybridized with 1.1 kb of human NQO1 cDNA (complete coding region) and the 2.0-kb neo-cassette probes.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
