Nucleoporin NUP153 guards genome integrity by promoting nuclear import of 53BP1

Moudrý, Pavel; Lukas, Claudia; Macůrek, Libor; Neumann, Beate; Jk, Heriche; Pepperkok, Rainer; Ellenberg, Jan; Hodný, Zdeněk; Lukáš, Jiří; Bártek, Jiří

doi:10.1038/cdd.2011.150

Cited by 71 publications

(64 citation statements)

References 45 publications

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“…Several studies reported the screening of genes in regulating the recruitment of 53BP1 to DNA damage sites (38)(39)(40). Depletion of UbcH7 was reported to increase the size of 53BP1 foci (30), similar to our observation.…”

Section: Discussionsupporting

confidence: 81%

UbcH7 regulates 53BP1 stability and DSB repair

Han¹,

Zhang²,

Chung³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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DNA double-strand break (DSB) repair is not only key to genome stability but is also an important anticancer target. Through an shRNA library-based screening, we identified ubiquitin-conjugating enzyme H7 (UbcH7, also known as Ube2L3), a ubiquitin E2 enzyme, as a critical player in DSB repair. UbcH7 regulates both the steady-state and replicative stress-induced ubiquitination and proteasome-dependent degradation of the tumor suppressor p53-binding protein 1 (53BP1). Phosphorylation of 53BP1 at the N terminus is involved in the replicative stress-induced 53BP1 degradation. Depletion of UbcH7 stabilizes 53BP1, leading to inhibition of DSB end resection. Therefore, UbcH7-depleted cells display increased nonhomologous end-joining and reduced homologous recombination for DSB repair. Accordingly, UbcH7-depleted cells are sensitive to DNA damage likely because they mainly used the errorprone nonhomologous end-joining pathway to repair DSBs. Our studies reveal a novel layer of regulation of the DSB repair choice and propose an innovative approach to enhance the effect of radiotherapy or chemotherapy through stabilizing 53BP1.DNA damage response | UbcH7 | 53BP1 | protein degradation | DSB repair P rompt response to double-strand breaks (DSBs) caused by, for example, ionization radiation (IR), requires sequential and coordinated assembly of DNA damage response (DDR) proteins at damage sites (1). Recent research findings reveal key roles of the tumor suppressor p53-binding protein 1 (53BP1) and BRCA1 in the decision making of DSB repair. 53BP1, together with Rif1, suppress BRCA1-dependent homologous recombination (HR), thereby promoting nonhomologous end-joining (NHEJ) in G1 phase (2-6). Conversely, BRCA1 antagonizes 53BP1/Rif1, favoring HR in S and G2 phases (7,8). In the absence of BRCA1 or with enhanced retention of 53BP1 at DSB sites, cells primarily use the error-prone NHEJ to repair DSBs throughout the cell cycle, which leads to gene rearrangement, cell death, and increased sensitivity to anticancer therapies (9-11). Consistently, BRCA1-null mice are early embryonic lethal (12, 13) and codepletion of TP53BP1 rescued the lethality phenotype of BRCA1-null mice (12)(13)(14).Low expression level of 53BP1 was found to be associated with poor clinical outcome in triple negative breast cancer patients with BRCA1 mutation (12, 15), as well as resistance to genotoxins and poly(ADP-ribose) polymerase inhibitors (12,16,17). This finding is probably because loss of 53BP1 restored HR and promoted cell survival (12-14). Reduced expression of 53BP1 was also observed in tumors from the brain (18), lymph node (19), and pancreas (20). These data indicate that loss of 53BP1 might be a common mechanism for advanced tumors to evade from radiotherapy or chemotherapy. However, molecular mechanisms controlling the protein level of 53BP1 remain less well understood.Here we show that UbcH7, an E2 enzyme involved in the ubiquitin (Ub) pathway, controls the protein stability of 53BP1, thereby determining the DSB repair choice. Loss of UbcH7 sta...

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Section: Discussionsupporting

confidence: 81%

UbcH7 regulates 53BP1 stability and DSB repair

Han¹,

Zhang²,

Chung³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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“…Indeed, previous work showed that depletion of NUP153 leads to import impairment of selective proteins. 16 Moreover, while we were conducting this study, Moudry et al 17 confirmed the mislocalization of 53BP1 in NUP153 depleted cells and showed the requirement of NUP153 for 53BP1 nuclear import.…”

Section: Resultssupporting

confidence: 64%

The nucleoporin 153, a novel factor in double-strand break repair and DNA damage response

et al. 2012

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DNA repair is essential in maintaining genome integrity and defects in different steps of the process have been linked to cancer and aging. It is a long lasting question how DNA repair is spatially and temporarily organized in the highly compartmentalized nucleus and whether the diverse nuclear compartments regulate differently the efficiency of repair. Increasing evidence suggest the involvement of nuclear pore complexes in repair of double-strand breaks (DSBs) in yeast. Here, we show that the human nucleoporin 153 (NUP153) has a role in repair of DSBs and in the activation of DNA damage checkpoints. We explore the mechanism of action of NUP153 and we propose its potential as a novel therapeutic target in cancers.Oncogene ( Keywords: DNA repair; nuclear pore; 53BP1 INTRODUCTION DNA double-strand breaks (DSBs) are particularly dangerous as their inefficient or inaccurate repair can result in mutations and chromosomal translocations that may induce cancer. 1 DSBs can be repaired by one of two major pathways: homology-based repair (homologous recombination (HR)) using the intact chromatid as a template present in proximity in S and G2 phases of the cell cycle, or direct joining across the break site (non-homologous end joining (NHEJ)). 2 The coordination between cell cycle progression and DSB repair (DSBR) is regulated by the DNA damage response (DDR) signalling pathway, which activates the cell cycle checkpoints in the presence of DNA breaks. 3 This pathway is initiated by the recruitment of the MRN (MRE11 --RAD50 --NBS1) sensor complex to sites of damage. The recruitment of MRN subsequently activates the ATM kinase, which associates with DSBs and phosphorylates the histone variant H2AX (g-H2AX). 2 MDC1 can then bind to gH2AX and recruit new MRN and ATM proteins, leading to spreading of the repair machinery along the chromosome. MDC1 also recruits ubiquitin ligases, such as RNF8 and RNF168, which facilitate the recruitment of the downstream factors 53BP1 and BRCA1. 2 When the DNA is resected to singlestranded DNA, it is recognized by replication protein A, which results in the recruitment of ATR. 2 Both the ATM and the ATR dependent branches of the pathway lead to the activation of the checkpoint kinases, CHK1 and CHK2, which stall damaged cells in their cell cycle until the lesions are resolved. 3 DNA repair, like all DNA-dependent processes, occur in the highly compartmentalized nucleus. Most nuclear events do not occur ubiquitously, but are limited to defined sites. 2 Several studies in yeast have shown that dedicated DNA repair centres exist as preferential sites of repair. 2,4 Furthermore, persistent DSBs in yeast migrate from their internal nuclear positions to the nuclear periphery, where they associate with nuclear pores. 5,6 This sequestration to the nuclear periphery was shown to require

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“…In this context, it has been shown that Nup153 mediates the nuclear import of the DNA repair mediator 53BP1 (also known as TP53BP1), regulating the nonhomologous end joining (NHEJ) pathway of DNA double-strand break (DSB) repair (Cobb et al, 2016;Lemaitre et al, 2012;Moudry et al, 2011). Nup50 appears to be required for the nuclear import of XRCC1, which plays roles in single-strand break and base excision repair (Kirby et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Localisation of Nup153 and SENP1 to nuclear pore complexes is required for 53BP1-mediated DNA double-strand break repair

Duhéron

Nilles

Pecenko

et al. 2017

Journal of Cell Science

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The nuclear basket of nuclear pore complexes (NPCs) is composed of three nucleoporins: Nup153, Nup50 and Tpr. Nup153 has a role in DNA double-strand break (DSB) repair by promoting nuclear import of 53BP1 (also known as TP53BP1), a mediator of the DNA damage response. Here, we provide evidence that loss of Nup153 compromises 53BP1 sumoylation, a prerequisite for efficient accumulation of 53BP1 at DSBs. Depletion of Nup153 resulted in reduced SUMO1 modification of 53BP1 and the displacement of the SUMO protease SENP1 from NPCs. Artificial tethering of SENP1 to NPCs restored non-homologous end joining (NHEJ) in the absence of Nup153 and re-established 53BP1 sumoylation. Furthermore, Nup50 and Tpr, the two other nuclear basket nucleoporins, also contribute to proper DSB repair, in a manner distinct from Nup153. Similar to the role of Nup153, Tpr is implicated in NHEJ and homologous recombination (HR), whereas loss of Nup50 only affects NHEJ. Despite the requirement of all three nucleoporins for accurate NHEJ, only Nup153 is needed for proper nuclear import of 53BP1 and SENP1-dependent sumoylation of 53BP1. Our data support the role of Nup153 as an important regulator of 53BP1 activity and efficient NHEJ.

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Nucleoporin NUP153 guards genome integrity by promoting nuclear import of 53BP1

Cited by 71 publications

References 45 publications

UbcH7 regulates 53BP1 stability and DSB repair

UbcH7 regulates 53BP1 stability and DSB repair

The nucleoporin 153, a novel factor in double-strand break repair and DNA damage response

Localisation of Nup153 and SENP1 to nuclear pore complexes is required for 53BP1-mediated DNA double-strand break repair

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