First published online December 20, 2006
Journal of Cell Science 120, 102e (2007)
© The Company of Biologists Limited
Speckles mark the spot for DNA repair
Metabolites and environmental agents continuously damage DNA; so, to avoid genomic instability, cells have DNA repair pathways that deal with different types of DNA lesion. Base excision repair (BER), for example, removes 8-oxoguanine and other modified bases produced by oxidative stress. Pablo Radicella and colleagues now reveal that UVA irradiation induces the relocalization of the first two enzymes in this pathway - the DNA glycolase hOGG1, which recognizes 8-oxoguanine, and the abasic endonuclease APE1 - to nuclear speckles, organelles involved in transcription and mRNA splicing (see p. 23). The authors show that the UVA-induced relocalization of hOGG1, which is homogeneously distributed in the nucleoplasm of untreated cells, does not depend on its recognition of 8-oxoguanine. Instead, they report, reactive oxygen species (ROS) induced by UVA irradiation provide the signal. Given that nuclear speckles are associated with the opening up of chromatin, the authors propose that these organelles might play a direct role in BER by helping components of the pathway to access damaged DNA.
Related articles in JCS:
- UVA irradiation induces relocalisation of the DNA repair protein hOGG1 to nuclear speckles
- Anna Campalans, Rachel Amouroux, Anne Bravard, Bernd Epe, and J. Pablo Radicella
JCS 2007 120: 23-32.
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