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Updated: Aug 3, 2026

Application of Laser Micro-irradiation for Examination of Single and Double Strand Break Repair in Mammalian Cells
Published on: September 5, 2017
Effect of damage type on stimulation of human excision nuclease by SWI/SNF chromatin remodeling factor
1Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA.
Abstract:
To investigate the repair of different types of DNA lesions in chromatin, we prepared mononucleosomes containing an acetylaminofluorene-guanine adduct (AAF-G), a (6-4) photoproduct, or a cyclobutane pyrimidine dimer (CPD) and measured the repair of these lesions by reconstituted 6-factor human excision nuclease. We find that incorporation into nucleosomes inhibits the repair of CPD more severely than repair of the AAF-G adduct and the (6-4) photoproduct. Equally important, we find that SWI/SNF stimulates the removal of AAF-G and (6-4) photoproduct but not of CPD from nucleosomal DNA. These results shed new light on the low rate of repair of CPDs in human cells in vivo.
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