| 1. |
- Marteijn, JA, et al.
(författare)
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Nucleotide excision repair-induced H2A ubiquitination is dependent on MDC1 and RNF8 and reveals a universal DNA damage response
- 2009
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Ingår i: The Journal of cell biology. - : Rockefeller University Press. - 1540-8140 .- 0021-9525. ; 186:6, s. 835-847
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Tidskriftsartikel (refereegranskat)abstract
- Chromatin modifications are an important component of the of DNA damage response (DDR) network that safeguard genomic integrity. Recently, we demonstrated nucleotide excision repair (NER)–dependent histone H2A ubiquitination at sites of ultraviolet (UV)-induced DNA damage. In this study, we show a sustained H2A ubiquitination at damaged DNA, which requires dynamic ubiquitination by Ubc13 and RNF8. Depletion of these enzymes causes UV hypersensitivity without affecting NER, which is indicative of a function for Ubc13 and RNF8 in the downstream UV–DDR. RNF8 is targeted to damaged DNA through an interaction with the double-strand break (DSB)–DDR scaffold protein MDC1, establishing a novel function for MDC1. RNF8 is recruited to sites of UV damage in a cell cycle–independent fashion that requires NER-generated, single-stranded repair intermediates and ataxia telangiectasia–mutated and Rad3-related protein. Our results reveal a conserved pathway of DNA damage–induced H2A ubiquitination for both DSBs and UV lesions, including the recruitment of 53BP1 and Brca1. Although both lesions are processed by independent repair pathways and trigger signaling responses by distinct kinases, they eventually generate the same epigenetic mark, possibly functioning in DNA damage signal amplification.
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| 2. |
- Pines, A, et al.
(författare)
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PARP1 promotes nucleotide excision repair through DDB2 stabilization and recruitment of ALC1
- 2012
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Ingår i: The Journal of cell biology. - : Rockefeller University Press. - 1540-8140 .- 0021-9525. ; 199:2, s. 235-249
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Tidskriftsartikel (refereegranskat)abstract
- The WD40-repeat protein DDB2 is essential for efficient recognition and subsequent removal of ultraviolet (UV)-induced DNA lesions by nucleotide excision repair (NER). However, how DDB2 promotes NER in chromatin is poorly understood. Here, we identify poly(ADP-ribose) polymerase 1 (PARP1) as a novel DDB2-associated factor. We demonstrate that DDB2 facilitated poly(ADP-ribosyl)ation of UV-damaged chromatin through the activity of PARP1, resulting in the recruitment of the chromatin-remodeling enzyme ALC1. Depletion of ALC1 rendered cells sensitive to UV and impaired repair of UV-induced DNA lesions. Additionally, DDB2 itself was targeted by poly(ADP-ribosyl)ation, resulting in increased protein stability and a prolonged chromatin retention time. Our in vitro and in vivo data support a model in which poly(ADP-ribosyl)ation of DDB2 suppresses DDB2 ubiquitylation and outline a molecular mechanism for PARP1-mediated regulation of NER through DDB2 stabilization and recruitment of the chromatin remodeler ALC1.
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