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Proc Natl Acad Sci U S A. 2011 Jan 25;108(4):1711-6. doi: 10.1073/pnas.1018359108. Epub 2011 Jan 10.

Extranuclear protection of chromosomal DNA from oxidative stress.

Author information

1
Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium.

Abstract

Eukaryotic organisms evolved under aerobic conditions subjecting nuclear DNA to damage provoked by reactive oxygen species (ROS). Although ROS are thought to be a major cause of DNA damage, little is known about the molecular mechanisms protecting nuclear DNA from oxidative stress. Here we show that protection of nuclear DNA in plants requires a coordinated function of ROS-scavenging pathways residing in the cytosol and peroxisomes, demonstrating that nuclear ROS scavengers such as peroxiredoxin and glutathione are insufficient to safeguard DNA integrity. Both catalase (CAT2) and cytosolic ascorbate peroxidase (APX1) play a key role in protecting the plant genome against photorespiratory-dependent H(2)O(2)-induced DNA damage. In apx1/cat2 double-mutant plants, a DNA damage response is activated, suppressing growth via a WEE1 kinase-dependent cell-cycle checkpoint. This response is correlated with enhanced tolerance to oxidative stress, DNA stress-causing agents, and inhibited programmed cell death.

PMID:
21220338
PMCID:
PMC3029710
DOI:
10.1073/pnas.1018359108
[Indexed for MEDLINE]
Free PMC Article

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