RIF1 in DNA Break Repair Pathway Choice
2013; Elsevier BV; Volume: 49; Issue: 5 Linguagem: Inglês
10.1016/j.molcel.2013.02.019
ISSN1097-4164
Autores Tópico(s)Acute Lymphoblastic Leukemia research
ResumoNew findings on the RIF1 protein by four research groups, including Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar and Escribano-Díaz et al., 2013Escribano-Díaz C. Orthwein A. Fradet-Turcotte A. Xing M. Young J.T.F. Tkáč J. Cook M.A. Rosebrock A.P. Munro M. Canny M.D. et al.Mol. Cell. 2013; 49 (this issue): 872-883Abstract Full Text Full Text PDF PubMed Scopus (628) Google Scholar in this issue, provide insights into DNA double-strand break repair pathway choice in mammalian cells. New findings on the RIF1 protein by four research groups, including Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar and Escribano-Díaz et al., 2013Escribano-Díaz C. Orthwein A. Fradet-Turcotte A. Xing M. Young J.T.F. Tkáč J. Cook M.A. Rosebrock A.P. Munro M. Canny M.D. et al.Mol. Cell. 2013; 49 (this issue): 872-883Abstract Full Text Full Text PDF PubMed Scopus (628) Google Scholar in this issue, provide insights into DNA double-strand break repair pathway choice in mammalian cells. DNA double-strand breaks (DSBs) are highly genotoxic as they can easily lead to chromosome deletions or translocations. DSBs are eliminated by either nonhomologous end joining (NHEJ), which involves the religation of DNA ends, or homologous recombination (HR), wherein a homologous sequence, usually the sister chromatid, guides repair. How cells select which pathway to use has remained a topic of intense investigation. Now, papers by the Durocher and Boulton groups in this issue of Molecular Cell, along with two papers from the de Lange and Nussenzweig groups recently published in Science, have shed light on this matter. These studies collectively implicate RIF1, originally identified as a regulator of telomere length in S. cerevisiae, as a key player in DSB repair pathway choice in mammals (Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar; Di Virgilio et al., 2013Di Virgilio M. Callen E. Yamane A. Zhang W. Jankovic M. Gitlin A.D. Feldhahn N. Resch W. Oliveira T.Y. Chait B.T. et al.Science. 2013; 339: 711-715Crossref PubMed Scopus (310) Google Scholar; Escribano-Díaz et al., 2013Escribano-Díaz C. Orthwein A. Fradet-Turcotte A. Xing M. Young J.T.F. Tkáč J. Cook M.A. Rosebrock A.P. Munro M. Canny M.D. et al.Mol. Cell. 2013; 49 (this issue): 872-883Abstract Full Text Full Text PDF PubMed Scopus (628) Google Scholar; Zimmermann et al., 2013Zimmermann M. Lottersberger F. Buonomo S.B. Sfeir A. de Lange T. Science. 2013; 339: 700-704Crossref PubMed Scopus (452) Google Scholar). HR begins with the nucleolytic resection of the 5′ strands of the break ends to generate single-stranded 3′ overhangs. This step commits repair to HR and is an important target for regulation. In G1 cells, when the sister chromatid is unavailable, resection is suppressed and only NHEJ is possible. In S phase, DSB end resection becomes activated to permit repair by HR. The cyclin-dependent kinase (CDK) activates DNA resection in S/G2 by phosphorylating CtIP (Sartori et al., 2007Sartori A.A. Lukas C. Coates J. Mistrik M. Fu S. Bartek J. Baer R. Lukas J. Jackson S.P. Nature. 2007; 450: 509-514Crossref PubMed Scopus (991) Google Scholar), whereas 53BP1 prevents it in G1 (Bothmer et al., 2010Bothmer A. Robbiani D.F. Feldhahn N. Gazumyan A. Nussenzweig A. Nussenzweig M.C. J. Exp. Med. 2010; 207: 855-865Crossref PubMed Scopus (217) Google Scholar). The BRCA1 protein promotes removal of 53BP1 in S phase to allow resection (Bunting et al., 2010Bunting S.F. Callén E. Wong N. Chen H.T. Polato F. Gunn A. Bothmer A. Feldhahn N. Fernandez-Capetillo O. Cao L. et al.Cell. 2010; 141: 243-254Abstract Full Text Full Text PDF PubMed Scopus (1168) Google Scholar). Thus, cells lacking BRCA1 fail to downregulate NHEJ in S phase, and chromosomal abnormalities arise from the inappropriate joining of replication-associated DSBs. In mice, 53BP1 deletion reverses the BRCA1 phenotypes, confirming that the role of BRCA1 is to remove 53BP1 and facilitate the transition from NHEJ to HR (Bouwman et al., 2010Bouwman P. Aly A. Escandell J.M. Pieterse M. Bartkova J. van der Gulden H. Hiddingh S. Thanasoula M. Kulkarni A. Yang Q. et al.Nat. Struct. Mol. Biol. 2010; 17: 688-695Crossref PubMed Scopus (720) Google Scholar; Bunting et al., 2010Bunting S.F. Callén E. Wong N. Chen H.T. Polato F. Gunn A. Bothmer A. Feldhahn N. Fernandez-Capetillo O. Cao L. et al.Cell. 2010; 141: 243-254Abstract Full Text Full Text PDF PubMed Scopus (1168) Google Scholar; Cao et al., 2009Cao L. Xu X. Bunting S.F. Liu J. Wang R.H. Cao L.L. Wu J.J. Peng T.N. Chen J. Nussenzweig A. et al.Mol. Cell. 2009; 35: 534-541Abstract Full Text Full Text PDF PubMed Scopus (225) Google Scholar). 53BP1 is phosphorylated by the ATM kinase upon DNA damage and accumulates at DSBs via an interaction with K20-methylated histone H4. The ATM phosphorylation sites on 53BP1 are required for resection attenuation but not for 53BP1 localization to DNA damage. These observations have suggested that 53BP1 recruits an effector molecule via a phospho-dependent interaction. Now the four research groups have independently identified RIF1 as the missing effector of 53BP1. Di Virgilio et al., 2013Di Virgilio M. Callen E. Yamane A. Zhang W. Jankovic M. Gitlin A.D. Feldhahn N. Resch W. Oliveira T.Y. Chait B.T. et al.Science. 2013; 339: 711-715Crossref PubMed Scopus (310) Google Scholar employed an affinity capture method to identify RIF1 as a P-53BP1 interactor. Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar, Escribano-Díaz et al., 2013Escribano-Díaz C. Orthwein A. Fradet-Turcotte A. Xing M. Young J.T.F. Tkáč J. Cook M.A. Rosebrock A.P. Munro M. Canny M.D. et al.Mol. Cell. 2013; 49 (this issue): 872-883Abstract Full Text Full Text PDF PubMed Scopus (628) Google Scholar, and Zimmermann et al., 2013Zimmermann M. Lottersberger F. Buonomo S.B. Sfeir A. de Lange T. Science. 2013; 339: 700-704Crossref PubMed Scopus (452) Google Scholar all used a candidate approach, noting that RIF1 is the only known factor that requires 53BP1 for recruitment to DSBs. All four studies confirm that RIF1 recruitment needs the ATM phosphorylation sites on 53BP1. The new studies show that, like 53BP1, RIF1 is required for NHEJ and class switch recombination (CSR), the process by which B cells change the type of antibody they produce via programmed DSB formation and rejoining by NHEJ (Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar; Di Virgilio et al., 2013Di Virgilio M. Callen E. Yamane A. Zhang W. Jankovic M. Gitlin A.D. Feldhahn N. Resch W. Oliveira T.Y. Chait B.T. et al.Science. 2013; 339: 711-715Crossref PubMed Scopus (310) Google Scholar; Escribano-Díaz et al., 2013Escribano-Díaz C. Orthwein A. Fradet-Turcotte A. Xing M. Young J.T.F. Tkáč J. Cook M.A. Rosebrock A.P. Munro M. Canny M.D. et al.Mol. Cell. 2013; 49 (this issue): 872-883Abstract Full Text Full Text PDF PubMed Scopus (628) Google Scholar). Both proteins are also involved in the fusion of uncapped telomeres via NHEJ (Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar; Zimmermann et al., 2013Zimmermann M. Lottersberger F. Buonomo S.B. Sfeir A. de Lange T. Science. 2013; 339: 700-704Crossref PubMed Scopus (452) Google Scholar). Importantly, 53BP1 and RIF1 are epistatic with respect to the repair of IR-induced DNA damage and CSR, indicating that they function together. 53BP1 and RIF1 dissociate from IR-induced foci as cells enter S phase, and their removal requires BRCA1 and CtIP (Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar; Escribano-Díaz et al., 2013Escribano-Díaz C. Orthwein A. Fradet-Turcotte A. Xing M. Young J.T.F. Tkáč J. Cook M.A. Rosebrock A.P. Munro M. Canny M.D. et al.Mol. Cell. 2013; 49 (this issue): 872-883Abstract Full Text Full Text PDF PubMed Scopus (628) Google Scholar). Upon treatment with a PARP inhibitor, BRCA1-deficient cells undergo chromosomal rearrangements as expected from inappropriate NHEJ of replication-associated DSBs. These are significantly reduced by 53BP1 or RIF1 depletion (Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar; Zimmermann et al., 2013Zimmermann M. Lottersberger F. Buonomo S.B. Sfeir A. de Lange T. Science. 2013; 339: 700-704Crossref PubMed Scopus (452) Google Scholar). Thus, BRCA1 likely prevents aberrant NHEJ events via 53BP1-RIF1 removal from DSBs. Importantly, CtIP phosphorylation site mutants fail to promote RIF1 removal, tying the previously characterized CDK-CtIP regulatory circuit to RIF1 (Escribano-Díaz et al., 2013Escribano-Díaz C. Orthwein A. Fradet-Turcotte A. Xing M. Young J.T.F. Tkáč J. Cook M.A. Rosebrock A.P. Munro M. Canny M.D. et al.Mol. Cell. 2013; 49 (this issue): 872-883Abstract Full Text Full Text PDF PubMed Scopus (628) Google Scholar; Sartori et al., 2007Sartori A.A. Lukas C. Coates J. Mistrik M. Fu S. Bartek J. Baer R. Lukas J. Jackson S.P. Nature. 2007; 450: 509-514Crossref PubMed Scopus (991) Google Scholar). Durocher and colleagues have also examined the nuclear dynamics of the aforementioned proteins. BRCA1 is present in cycling G1 cells, and loss of 53BP1 or RIF1 leads to ectopic BRCA1 foci. Consistent with this, RIF1 ablation is accompanied by an increase in resection at IR-induced DSBs and during CSR events (Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar; Di Virgilio et al., 2013Di Virgilio M. Callen E. Yamane A. Zhang W. Jankovic M. Gitlin A.D. Feldhahn N. Resch W. Oliveira T.Y. Chait B.T. et al.Science. 2013; 339: 711-715Crossref PubMed Scopus (310) Google Scholar). Depletion of 53BP1 or RIF1 restores resection in the BRCA1 mutant but fails to do so in CtIP-deficient cells (Escribano-Díaz et al., 2013Escribano-Díaz C. Orthwein A. Fradet-Turcotte A. Xing M. Young J.T.F. Tkáč J. Cook M.A. Rosebrock A.P. Munro M. Canny M.D. et al.Mol. Cell. 2013; 49 (this issue): 872-883Abstract Full Text Full Text PDF PubMed Scopus (628) Google Scholar). It thus seems likely that CtIP has another role in resection beyond RIF1 removal, e.g., via stimulation of the MRE11 nuclease activity that is known to be required for efficient resection. Boulton and colleagues have generated and characterized RIF1−/− mice (Chapman et al., 2013Chapman J.R. Barral P. Vannier J.-B. Borel V. Steger M. Tomas-Loba A. Sartori A.A. Adams I.R. Batista F.D. Boulton S.J. Mol. Cell. 2013; 49 (this issue): 858-871Abstract Full Text Full Text PDF PubMed Scopus (452) Google Scholar). These mice develop normally and have no lymphocyte development defects, indicating that V(D)J recombination is unaffected. They are deficient in CSR, however. Why might CSR ends, but not V(D)J ends, be susceptible to inappropriate resection in the absence of RIF1? This may be explained by redundant mechanisms of end protection. Indeed, the NHEJ factor XLF has been shown to act redundantly with 53BP1 to protect V(D)J ends from resection (Oksenych et al., 2012Oksenych V. Alt F.W. Kumar V. Schwer B. Wesemann D.R. Hansen E. Patel H. Su A. Guo C. Proc. Natl. Acad. Sci. USA. 2012; 109: 2455-2460Crossref PubMed Scopus (60) Google Scholar). The structure of the DSB ends may play a role, too. Coding ends during V(D)J recombination are made by the RAG1/RAG2 recombinase and exist as a hairpin that may be resistant to resection. In addition, RAG1/RAG2 has affinity to these ends and may block resection. CSR ends, on the other hand, are formed after DNA is nicked multiply in close proximity by AID. Together, the four new papers provide a significant advance in our understanding of DNA end resection regulation and DSB repair pathway choice. The prevailing model has been that CtIP phosphorylation affects resection primarily via activation of the MRE11 nuclease activity (Sartori et al., 2007Sartori A.A. Lukas C. Coates J. Mistrik M. Fu S. Bartek J. Baer R. Lukas J. Jackson S.P. Nature. 2007; 450: 509-514Crossref PubMed Scopus (991) Google Scholar). Now, RIF1 removal in concert with BRCA1 can be added as another major event triggered by CtIP phosphorylation. In a unified model, phosphorylated CtIP likely displaces 53BP1-RIF1 while recruiting the MRE11-RAD50-NBS1 (MRN) complex (Figure 1). The identification of a cell-cycle-dependent CtIP-BRCA1-MRN ensemble suggests that these events occur simultaneously (Chen et al., 2008Chen L. Nievera C.J. Lee A.Y. Wu X. J. Biol. Chem. 2008; 283: 7713-7720Crossref PubMed Scopus (321) Google Scholar). Future studies will be needed to address the mechanism by which this complex evicts 53BP1-RIF1 from DSBs. A Cell Cycle-Dependent Regulatory Circuit Composed of 53BP1-RIF1 and BRCA1-CtIP Controls DNA Repair Pathway ChoiceEscribano-Díaz et al.Molecular CellJanuary 17, 2013In BriefDNA double-strand break (DSB) repair pathway choice is governed by the opposing activities of 53BP1 and BRCA1. 53BP1 stimulates nonhomologous end joining (NHEJ), whereas BRCA1 promotes end resection and homologous recombination (HR). Here we show that 53BP1 is an inhibitor of BRCA1 accumulation at DSB sites, specifically in the G1 phase of the cell cycle. ATM-dependent phosphorylation of 53BP1 physically recruits RIF1 to DSB sites, and we identify RIF1 as the critical effector of 53BP1 during DSB repair. Full-Text PDF Open ArchiveRIF1 Is Essential for 53BP1-Dependent Nonhomologous End Joining and Suppression of DNA Double-Strand Break ResectionChapman et al.Molecular CellJanuary 17, 2013In BriefThe appropriate execution of DNA double-strand break (DSB) repair is critical for genome stability and tumor avoidance. 53BP1 and BRCA1 directly influence DSB repair pathway choice by regulating 5′ end resection, but how this is achieved remains uncertain. Here we report that Rif1−/− mice are severely compromised for 53BP1-dependent class switch recombination (CSR) and fusion of dysfunctional telomeres. The inappropriate accumulation of RIF1 at DSBs in S phase is antagonized by BRCA1, and deletion of Rif1 suppresses toxic nonhomologous end joining (NHEJ) induced by PARP inhibition in Brca1-deficient cells. Full-Text PDF Open Access
Referência(s)