Chromatin remodeling facilitates DNA incision in UV-damaged nucleosomes.
The DNA repair machinery must locate and repair DNA damage all over the genome. As nucleosomes inhibit DNA repair in vitro, it has been suggested that chromatin remodeling might be required for efficient repair in vivo. To investigate a possible contribution of nucleosome dynamics and chromatin remodeling to the repair of UV-photoproducts in nucleosomes, we examined the effect of a chromatin remodeling complex on the repair of UV-lesions by Micrococcus luteus UV endonuclease (ML-UV endo) and T4-endonuclease V (T4-endoV) in reconstituted mononucleosomes positioned at one end of a 175-bp long DNA fragment. Repair by ML-UV endo and T4-endoV was inefficient in mononucleosomes compared with naked DNA. However, the human nucleosome remodeling complex, hSWI/SNF, promoted more homogeneous repair by ML-UV endo and T4-endo V in reconstituted nucleosomes. This result suggests that recognition of DNA damage could be facilitated by a fluid state of the chromatin resulting from chromatin remodeling activities.
Lee
Kyungeun
K
Department of Life Sciences, College of Natural Sciences, University of Ulsan, Ulsan 680-749, Korea.
Kim
Deok Ryong
DR
Ahn
Byungchan
B
D000818:Animals; D002645:Chickens; D042002:Chromatin Assembly and Disassembly; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D004249:DNA Damage; D004260:DNA Repair; D004706:Endodeoxyribonucleases / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D009707:Nucleosomes / Q000378:metabolism / Q000528:radiation effects*; D012341:RNA, Ribosomal, 5S / Q000378:metabolism / Q000528:radiation effects; D014157:Transcription Factors / Q000378:metabolism; D014466:Ultraviolet Rays; D014982:Xenopus laevis
D002868:Chromosomal Proteins, Non-Histone; D046911:Macromolecular Substances; D009707:Nucleosomes; D012341:RNA, Ribosomal, 5S; C445179:SWI-SNF-B chromatin-remodeling complex; D014157:Transcription Factors; D004706:Endodeoxyribonucleases; C044931:gamma endonuclease, Micrococcus luteus