Journal article
UV damage in DNA promotes nucleosome unwrapping
The Journal of biological chemistry, Vol.285(34), pp.26295-26303
08/20/2010
Handle:
https://hdl.handle.net/2376/100524
PMCID: PMC2924050
PMID: 20562439
Abstract
The association of DNA with histones in chromatin impedes DNA repair enzymes from accessing DNA lesions. Nucleosomes exist in a dynamic equilibrium in which portions of the DNA molecule spontaneously unwrap, transiently exposing buried DNA sites. Thus, nucleosome dynamics in certain regions of chromatin may provide the exposure time and space needed for efficient repair of buried DNA lesions. We have used FRET and restriction enzyme accessibility to study nucleosome dynamics following DNA damage by UV radiation. We find that FRET efficiency is reduced in a dose-dependent manner, showing that the presence of UV photoproducts enhances spontaneous unwrapping of DNA from histones. Furthermore, this UV-induced shift in unwrapping dynamics is associated with increased restriction enzyme accessibility of histone-bound DNA after UV treatment. Surprisingly, the increased unwrapping dynamics is even observed in nucleosome core particles containing a single UV lesion at a specific site. These results highlight the potential for increased "intrinsic exposure" of nucleosome-associated DNA lesions in chromatin to repair proteins.
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Details
- Title
- UV damage in DNA promotes nucleosome unwrapping
- Creators
- Ming-Rui Duan - Biochemistry and Biophysics, School of Molecular Biosciences, Washington State University, Pullman, Washington 99164-7520, USAMichael J Smerdon
- Publication Details
- The Journal of biological chemistry, Vol.285(34), pp.26295-26303
- Academic Unit
- Molecular Biosciences, School of
- Publisher
- United States
- Grant note
- R01 ES004106 / NIEHS NIH HHS ES004106 / NIEHS NIH HHS
- Identifiers
- 99900546526801842
- Language
- English
- Resource Type
- Journal article