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RNF4, a SUMO-targeted ubiquitin E3 ligase, promotes DNA double-strand break repair
Open accessAbstract
Protein ubiquitylation and sumoylation play key roles in regulating cellular responses to DNA double-strand breaks (DSBs). Here, we show that human RNF4, a small ubiquitin-like modifier (SUMO)-targeted ubiquitin E3 ligase, is recruited to DSBs in a manner requiring its SUMO interaction motifs, the SUMO E3 ligases PIAS1 and PIAS4, and various DSB-responsive proteins. Furthermore, we reveal that RNF4 depletion impairs ubiquitin adduct formation at DSB sites and causes persistent histone H2AX phosphorylation (γH2AX) associated with defective DSB repair, hypersensitivity toward DSB-inducing agents, and delayed recovery from radiation-induced cell cycle arrest. We establish that RNF4 regulates turnover of the DSB-responsive factors MDC1 and replication protein A (RPA) at DNA damage sites and that RNF4-depleted cells fail to effectively replace RPA by the homologous recombination factors BRCA2 and RAD51 on resected DNA. Consistent with previous data showing that RNF4 targets proteins to the proteasome, we show that the proteasome component PSMD4 is recruited to DNA damage sites in a manner requiring its ubiquitin-interacting domains, RNF4 and RNF8. Finally, we establish that PSMD4 binds MDC1 and RPA1 in a DNA damage-induced, RNF4-dependent manner and that PSMD4 depletion cause MDC1 and γH2AX persistence in irradiated cells. RNF4 thus operates as a DSB response factor at the crossroads between the SUMO and ubiquitin systems.
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“RNF4, a SUMO-targeted ubiquitin E3 ligase, is recruited to DSBs by MDC1 and promotes DNA repair and cellular response to DSBs [66, 67].”
From Functional interplay between ATM/ATR-mediated DNA damage response and DNA repair pathways in oxidative stress (2014) · cites this paper as [67]
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Citations
Cites
The DNA-damage response in human biology and disease
Jackson, S. P., & Bartek, J. (2009) · Nature · doi:10.1038/nature08467 · Cited by 6,092
Self-citationThe DNA Damage Response: Making It Safe to Play with Knives
Ciccia, A., & Elledge, S. J. (2010) · Molecular Cell · doi:10.1016/j.molcel.2010.09.019 · Cited by 4,368
ATM and ATR Substrate Analysis Reveals Extensive Protein Networks Responsive to DNA Damage
Matsuoka, S., Ballif, B. A., Smogorzewska, A., McDonald, E. R., Hurov, K. E., Luo, J., Bakalarski, C. E., Zhao, Z., Solimini, N., Lerenthal, Y., et al. (2007) · Science · doi:10.1126/science.1140321 · Cited by 3,075
Sensing DNA Damage Through ATRIP Recognition of RPA-ssDNA Complexes
Zou, L., & Elledge, S. J. (2003) · Science · doi:10.1126/science.1083430 · Cited by 2,693
ATR: an essential regulator of genome integrity
Cimprich, K. A., & Cortez, D. (2008) · Nature Reviews Molecular Cell Biology · doi:10.1038/nrm2450 · Cited by 1,798
53BP1 Inhibits Homologous Recombination in Brca1-Deficient Cells by Blocking Resection of DNA Breaks
Bunting, S. F., Callén, E., Wong, N., Chen, H.-T., Polato, F., Gunn, A., Bothmer, A., Feldhahn, N., Fernandez-Capetillo, O., Cao, L., et al. (2010) · Cell · doi:10.1016/j.cell.2010.03.012 · Cited by 1,671
Hay, R. T. (2005) · Molecular Cell · doi:10.1016/j.molcel.2005.03.012 · Cited by 1,656
Human CtIP promotes DNA end resection
Sartori, A. A., Lukas, C., Coates, J., Mistrik, M., Fu, S., Bartek, J., Baer, R., Lukas, J., & Jackson, S. P. (2007) · Nature · doi:10.1038/nature06337 · Cited by 1,362
Self-citationRNF8 Ubiquitylates Histones at DNA Double-Strand Breaks and Promotes Assembly of Repair Proteins
Mailand, N., Bekker‐Jensen, S., Kildegaard, H. F., Melander, F., Bártek, J., Lukas, C., & Lukas, J. (2007) · Cell · doi:10.1016/j.cell.2007.09.040 · Cited by 1,193
Stucki, M., Clapperton, J. A., Mohammad, D. H., Yaffe, M. B., Smerdon, S. J., & Jackson, S. P. (2005) · Cell · doi:10.1016/j.cell.2005.09.038 · Cited by 1,164
Self-citationDynamics of DNA damage response proteins at DNA breaks: a focus on protein modifications
Polo, S. E., & Jackson, S. P. (2011) · Genes & Development · doi:10.1101/gad.2021311 · Cited by 1,092
Self-citationRNF8 Transduces the DNA-Damage Signal via Histone Ubiquitylation and Checkpoint Protein Assembly
Huen, M. S. Y., Grant, R. A., Manke, I. A., Minn, K. T., Yu, X., Yaffe, M. B., & Chen, J. (2007) · Cell · doi:10.1016/j.cell.2007.09.041 · Cited by 1,068
ATR and ATRIP: Partners in Checkpoint Signaling
Cortez, D., Guntuku, S., Qin, J., & Elledge, S. J. (2001) · Science · doi:10.1126/science.1065521 · Cited by 985
Doil, C., Mailand, N., Bekker‐Jensen, S., Ménard, P., Larsen, D. H., Pepperkok, R., Ellenberg, J., Panier, S., Durocher, D., Bártek, J., et al. (2009) · Cell · doi:10.1016/j.cell.2008.12.041 · Cited by 982
Orchestration of the DNA-Damage Response by the RNF8 Ubiquitin Ligase
Kolas, N. K., Chapman, J. R., Nakada, S., Ylanko, J., Chahwan, R., Sweeney, F. D., Panier, S., Mendez, M., Wildenhain, J., Thomson, T. M., et al. (2007) · Science · doi:10.1126/science.1150034 · Cited by 932
Self-citationRNF4 is a poly-SUMO-specific E3 ubiquitin ligase required for arsenic-induced PML degradation
Tatham, M. H., Geoffroy, M., Shen, L., Plechanovová, A., Hattersley, N., Jaffray, E., Palvimo, J. J., & Hay, R. T. (2008) · Nature Cell Biology · doi:10.1038/ncb1716 · Cited by 837
Nimonkar, A. V., Genschel, J., Kinoshita, E., Polaczek, P., Campbell, J. L., Wyman, C., Modrich, P. L., & Kowalczykowski, S. C. (2011) · Genes & Development · doi:10.1101/gad.2003811 · Cited by 825
The RIDDLE Syndrome Protein Mediates a Ubiquitin-Dependent Signaling Cascade at Sites of DNA Damage
Stewart, G. S., Panier, S., Townsend, K., Al-Hakim, A., Kolas, N. K., Miller, E. S., Nakada, S., Ylanko, J., Olivarius, S., Mendez, M., et al. (2009) · Cell · doi:10.1016/j.cell.2008.12.042 · Cited by 757
Arsenic degrades PML or PML–RARα through a SUMO-triggered RNF4/ubiquitin-mediated pathway
Lallemand-Breitenbach, V., Jeanne, M., Benhenda, S., Nasr, R., Lei, M., Pérès, L., Zhou, J., Zhu, J., Raught, B., & de Thé, H. (2008) · Nature Cell Biology · doi:10.1038/ncb1717 · Cited by 726
Purified human BRCA2 stimulates RAD51-mediated recombination
Jensen, R. B., Carreira, A., & Kowalczykowski, S. C. (2010) · Nature · doi:10.1038/nature09399 · Cited by 715
Spatial organization of the mammalian genome surveillance machinery in response to DNA strand breaks
Bekker‐Jensen, S., Lukas, C., Kitagawa, R., Melander, F., Kastan, M. B., Bártek, J., & Lukas, J. (2006) · The Journal of Cell Biology · doi:10.1083/jcb.200510130 · Cited by 647
DNA helicases Sgs1 and BLM promote DNA double-strand break resectionPreprint
Gravel, S., Chapman, J. R., Magill, C. P., & Jackson, S. P. (2008) · Genes & Development · doi:10.1101/gad.503108 · Cited by 595
Self-citationPrinciples of ubiquitin and SUMO modifications in DNA repair
Bergink, S., & Jentsch, S. (2009) · Nature · doi:10.1038/nature07963 · Cited by 554
Mammalian SUMO E3-ligases PIAS1 and PIAS4 promote responses to DNA double-strand breaks
Galanty, Y., Belotserkovskaya, R., Coates, J., Polo, S. E., Miller, K. M., & Jackson, S. P. (2009) · Nature · doi:10.1038/nature08657 · Cited by 536
Self-citationKu DNA end-binding protein modulates homologous repair of double-strand breaks in mammalian cellsPreprint
Pierce, A. J., Hu, P., Han, M., Ellis, N. A., & Jasin, M. (2001) · Genes & Development · doi:10.1101/gad.946401 · Cited by 514
Wang, B., & Elledge, S. J. (2007) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0710061104 · Cited by 464
Human BRCA2 protein promotes RAD51 filament formation on RPA-covered single-stranded DNA
Liu, J., Doty, T., Gibson, B. A., & Heyer, W. (2010) · Nature Structural & Molecular Biology · doi:10.1038/nsmb.1904 · Cited by 432
DNA resection in eukaryotes: deciding how to fix the break
Huertas, P. (2010) · Nature Structural & Molecular Biology · doi:10.1038/nsmb.1710 · Cited by 424
Mechanisms of double-strand break repair in somatic mammalian cells
Hartlerode, A. J., & Scully, R. (2009) · Biochemical Journal · doi:10.1042/bj20090942 · Cited by 395
The SUMO modification pathway is involved in the BRCA1 response to genotoxic stress
Morris, J. R., Boutell, C., Keppler, M., Densham, R., Weekes, D., Alamshah, A., Butler, L., Galanty, Y., Pangon, L., Kiuchi, T., et al. (2009) · Nature · doi:10.1038/nature08593 · Cited by 375
Self-citationAssembly and function of DNA double-strand break repair foci in mammalian cells
Bekker-Jensen, S., & Mailand, N. (2010) · DNA Repair · doi:10.1016/j.dnarep.2010.09.010 · Cited by 338
SUMO‐targeted ubiquitin ligases in genome stability
Prudden, J., Kaeser-Pebernard, S., Raffa, G. D., Slavin, D. A., Perry, J. J. P., Tainer, J. A., McGowan, C. H., & Boddy, M. N. (2007) · The EMBO Journal · doi:10.1038/sj.emboj.7601838 · Cited by 334
PA200, a nuclear proteasome activator involved in DNA repair
Ustrell, V., Hoffman, L., Pratt, G., & Rechsteiner, M. (2002) · The EMBO Journal · doi:10.1093/emboj/cdf333 · Cited by 325
Human exonuclease 1 and BLM helicase interact to resect DNA and initiate DNA repair
Nimonkar, A. V., Özsoy, A. Z., Genschel, J., Modrich, P. L., & Kowalczykowski, S. C. (2008) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0809380105 · Cited by 322
Characterization of Two Polyubiquitin Binding Sites in the 26 S Protease Subunit 5a
Young, P., Deveraux, Q. L., Beal, R. E., Pickart, C. M., & Rechsteiner, M. (1998) · Journal of Biological Chemistry · doi:10.1074/jbc.273.10.5461 · Cited by 313
Expanded roles of the Fanconi anemia pathway in preserving genomic stabilityPreprint
Kee, Y., & D’Andrea, A. D. (2010) · Genes & Development · doi:10.1101/gad.1955310 · Cited by 311
RAD18 transmits DNA damage signalling to elicit homologous recombination repair
Huang, J., Huen, M. S. Y., Kim, H., Leung, C. C. Y., Glover, J. N. M., Yu, X., & Chen, J. (2009) · Nature Cell Biology · doi:10.1038/ncb1865 · Cited by 308
Sun, H., Leverson, J. D., & Hunter, T. R. (2007) · The EMBO Journal · doi:10.1038/sj.emboj.7601839 · Cited by 299
Chapman, J. R., & Jackson, S. P. (2008) · EMBO Reports · doi:10.1038/embor.2008.103 · Cited by 299
Self-citationChromatin dynamics and the preservation of genetic information
Downs, J. A., Nussenzweig, M. C., & Nussenzweig, A. (2007) · Nature · doi:10.1038/nature05980 · Cited by 296
DNA Repair in Mammalian Cells: DNA double-strand break repair: how to fix a broken relationship
Pardo, B., Gómez-González, B., & Aguilera, A. (2009) · Cellular and Molecular Life Sciences · doi:10.1007/s00018-009-8740-3 · Cited by 280
Stadtmueller, B. M., & Hill, C. P. (2011) · Molecular Cell · doi:10.1016/j.molcel.2010.12.020 · Cited by 279
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Bekker‐Jensen, S., Danielsen, J. M. R., Fugger, K., Gromova, I., Nerstedt, A., Lukas, C., Bártek, J., Lukas, J., & Mailand, N. (2009) · Nature Cell Biology · doi:10.1038/ncb2008 · Cited by 277
Thorslund, T., McIlwraith, M. J., Compton, S. A., Lekomtsev, S., Petronczki, M. P., Griffith, J. D., & West, S. C. (2010) · Nature Structural & Molecular Biology · doi:10.1038/nsmb.1905 · Cited by 262
Xie, A., Hartlerode, A. J., Stucki, M., Odate, S., Puget, N., Kwok, A., Nagaraju, G., Yan, C. T., Alt, F. W., Chen, J., et al. (2007) · Molecular Cell · doi:10.1016/j.molcel.2007.12.005 · Cited by 242
Self-citationThe ubiquitous role of ubiquitin in the DNA damage response
Al-Hakim, A., Escribano‐Diaz, C., Landry, M.-C., O’Donnell, L., Panier, S., Szilard, R. K., & Durocher, D. (2010) · DNA repair · doi:10.1016/j.dnarep.2010.09.011 · Cited by 240
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Holloman, W. K. (2011) · Nature Structural & Molecular Biology · doi:10.1038/nsmb.2096 · Cited by 230
A Critical Role for the Ubiquitin-Conjugating Enzyme Ubc13 in Initiating Homologous Recombination
Zhao, G., Sonoda, E., Barber, L. J., Oka, H., Murakawa, Y., Yamada, K., Ikura, T., Wang, X., Kobayashi, M., Yamamoto, K., et al. (2007) · Molecular Cell · doi:10.1016/j.molcel.2007.01.029 · Cited by 220
Proteasome Function Is Required for DNA Damage Response and Fanconi Anemia Pathway Activation
Jacquemont, C. F., & Taniguchi, T. (2007) · Cancer Research · doi:10.1158/0008-5472.can-07-1015 · Cited by 213
Regulation of DNA Repair through DeSUMOylation and SUMOylation of Replication Protein A Complex
Dou, H., Huang, C., Singh, M. M., Carpenter, P. B., & Yeh, E. T. H. (2010) · Molecular Cell · doi:10.1016/j.molcel.2010.07.021 · Cited by 212
Role of ubiquitin- and Ubl-binding proteins in cell signaling
Kirkin, V., & Đikić, I. (2007) · Current Opinion in Cell Biology · doi:10.1016/j.ceb.2007.02.002 · Cited by 200
Proteasome activator PA28γ regulates p53 by enhancing its MDM2‐mediated degradation
Zhang, Z., & Zhang, R. (2008) · The EMBO Journal · doi:10.1038/emboj.2008.25 · Cited by 151
Burgess, R. C., Rahman, S., Lisby, M., Rothstein, R. J., & Zhao, X. (2007) · Molecular and Cellular Biology · doi:10.1128/mcb.00787-07 · Cited by 135
A New Method for Introducing Double-Strand Breaks into Cellular DNA
Limoli, C. L., & Ward, J. F. (1993) · Radiation Research · doi:10.2307/3578455 · Cited by 128
Inhibitors of the Proteasome Suppress Homologous DNA Recombination in Mammalian Cells
Murakawa, Y., Sonoda, E., Barber, L. J., Zeng, W., Yokomori, K., Kimurâ, H., Niimi, A., Lehmann, A. R., Zhao, G., Hochegger, H., et al. (2007) · Cancer Research · doi:10.1158/0008-5472.can-07-1166 · Cited by 108
Weisshaar, S. R., Keusekotten, K., Krause, A., Horst, C., Springer, H. M., Göttsche, K., Dohmen, R. J., & Praefcke, G. J. K. (2008) · FEBS Letters · doi:10.1016/j.febslet.2008.08.008 · Cited by 105
Role for proteasome activator PA200 and postglutamyl proteasome activity in genomic stability
Blickwedehl, J., Agarwal, M., Seong, C., PANDITA, R. K., Melendy, T., Sung, P., Pandita, T. K., & Bangia, N. (2008) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0803145105 · Cited by 103
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Watanabe, K., Iwabuchi, K., Sun, J., Tsuji, Y., Tani, T., Tokunaga, K., Date, T., HASHIMOTO, M. W., Yamaizumi, M., & Tateishi, S. (2009) · Nucleic Acids Research · doi:10.1093/nar/gkp082 · Cited by 75
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Shi, W., Ma, Z., Willers, H., Akhtar, K., Scott, S. P., Zhang, J., Powell, S. N., & Zhang, J. (2008) · Journal of Biological Chemistry · doi:10.1074/jbc.m801082200 · Cited by 71
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Levy‐Barda, A., Lerenthal, Y., Davis, A. J., Chung, Y. M., Essers, J., Shao, Z., van Vliet, N., Chen, D. J., Hu, M. C. ‐., Kanaar, R., et al. (2011) · Cell Cycle · doi:10.4161/cc.10.24.18642 · Cited by 66
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Häkli, M., Lorick, K. L., Weissman, A. M., Jänne, O. A., & Palvimo, J. J. (2004) · FEBS Letters · doi:10.1016/s0014-5793(04)00070-5 · Cited by 61
RAD18-dependent Recruitment of SNM1A to DNA Repair Complexes by a Ubiquitin-binding Zinc Finger
Yang, K., Moldovan, G., & D’Andrea, A. D. (2010) · Journal of Biological Chemistry · doi:10.1074/jbc.m109.100032 · Cited by 58
Blickwedehl, J., McEvoy, S. M., Wong, I., Kousis, P. C., Clements, J. L., Elliott, R. W., Cresswell, P., Liang, P., & Bangia, N. (2007) · Radiation Research · doi:10.1667/rr0690.1 · Cited by 57
The vital link between the ubiquitin–proteasome pathway and DNA repair: Impact on cancer therapy
Motegi, A., Murakawa, Y., & Takeda, S. (2009) · Cancer Letters · doi:10.1016/j.canlet.2008.12.030 · Cited by 53
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Self-citation
Metadata
- Authors
- Galanty, Y., Belotserkovskaya, R., Coates, J., & Jackson, S. P.
- Affiliations
- University of Cambridge (GB)
- Venue
- Genes & Development
- Publisher
- Cold Spring Harbor Laboratory
- Published
- 2012-06-01
- Volume
- 26
- Issue
- 11
- Pages
- 1179-1195
- ISSN
- 0890-9369 (ISSN-L)
- 1549-5477
- PMC
- PMC3371407
- OpenAlex
- W2113354406
- Cited by
- 314
- References
- 68
- Citations by year
- 2026: 12 · 2025: 12 · 2024: 15 · 2023: 14 · 2022: 20 · 2021: 19 · 2020: 19 · 2019: 16 · 2018: 14 · 2017: 30 · 2016: 37 · 2015: 27 · 2014: 26 · 2013: 37 · 2012: 15
- Type
- posted content
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Genes & Development (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Funders
- Wellcome Trust (092096)
- Cancer Research UK (C6/A11226, 11224, A11224)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › DNA Repair Mechanisms
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Ubiquitin and proteasome pathways
- Health Sciences › Medicine › Radiology, Nuclear Medicine and Imaging › Effects of Radiation Exposure
- Keywords
- RNF4, DNA double-strand break repair, SUMO interaction motif, PIAS1, PIAS4, H2AX phosphorylation, MDC1, replication protein A, BRCA2, RAD51, homologous recombination, proteasome, PSMD4, RNF8, radiation-induced cell cycle arrest, DNA damage response
- MeSH terms
- DNA Repair, DNA, Single-Stranded, Histones, Humans, Nuclear Proteins, Transcription Factors, Trans-Activators, Cell Cycle Proteins, Ubiquitin-Protein Ligases, Cell Line, Tumor, Proteasome Endopeptidase Complex, Adaptor Proteins, Signal Transducing, Rad51 Recombinase, Replication Protein A, DNA Breaks, Double-Stranded
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