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Filograna A, De Tito S, Monte ML, Oliva R, Bruzzese F, Roca MS, Zannetti A, Greco A, Spano D, Ayala I, Liberti A, Petraccone L, Dathan N, Catara G, Schembri L, Colanzi A, Budillon A, Beccari AR, Del Vecchio P, Luini A, Corda D, Valente C. Identification and characterization of a new potent inhibitor targeting CtBP1/BARS in melanoma cells. J Exp Clin Cancer Res 2024; 43:137. [PMID: 38711119 PMCID: PMC11071220 DOI: 10.1186/s13046-024-03044-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 04/10/2024] [Indexed: 05/08/2024] Open
Abstract
BACKGROUND The C-terminal-binding protein 1/brefeldin A ADP-ribosylation substrate (CtBP1/BARS) acts both as an oncogenic transcriptional co-repressor and as a fission inducing protein required for membrane trafficking and Golgi complex partitioning during mitosis, hence for mitotic entry. CtBP1/BARS overexpression, in multiple cancers, has pro-tumorigenic functions regulating gene networks associated with "cancer hallmarks" and malignant behavior including: increased cell survival, proliferation, migration/invasion, epithelial-mesenchymal transition (EMT). Structurally, CtBP1/BARS belongs to the hydroxyacid-dehydrogenase family and possesses a NAD(H)-binding Rossmann fold, which, depending on ligands bound, controls the oligomerization of CtBP1/BARS and, in turn, its cellular functions. Here, we proposed to target the CtBP1/BARS Rossmann fold with small molecules as selective inhibitors of mitotic entry and pro-tumoral transcriptional activities. METHODS Structured-based screening of drug databases at different development stages was applied to discover novel ligands targeting the Rossmann fold. Among these identified ligands, N-(3,4-dichlorophenyl)-4-{[(4-nitrophenyl)carbamoyl]amino}benzenesulfonamide, called Comp.11, was selected for further analysis. Fluorescence spectroscopy, isothermal calorimetry, computational modelling and site-directed mutagenesis were employed to define the binding of Comp.11 to the Rossmann fold. Effects of Comp.11 on the oligomerization state, protein partners binding and pro-tumoral activities were evaluated by size-exclusion chromatography, pull-down, membrane transport and mitotic entry assays, Flow cytometry, quantitative real-time PCR, motility/invasion, and colony assays in A375MM and B16F10 melanoma cell lines. Effects of Comp.11 on tumor growth in vivo were analyzed in mouse tumor model. RESULTS We identify Comp.11 as a new, potent and selective inhibitor of CtBP1/BARS (but not CtBP2). Comp.11 directly binds to the CtBP1/BARS Rossmann fold affecting the oligomerization state of the protein (unlike other known CtBPs inhibitors), which, in turn, hinders interactions with relevant partners, resulting in the inhibition of both CtBP1/BARS cellular functions: i) membrane fission, with block of mitotic entry and cellular secretion; and ii) transcriptional pro-tumoral effects with significantly hampered proliferation, EMT, migration/invasion, and colony-forming capabilities. The combination of these effects impairs melanoma tumor growth in mouse models. CONCLUSIONS: This study identifies a potent and selective inhibitor of CtBP1/BARS active in cellular and melanoma animal models revealing new opportunities to study the role of CtBP1/BARS in tumor biology and to develop novel melanoma treatments.
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Affiliation(s)
- Angela Filograna
- Institute of Experimental Endocrinology and Oncology "G. Salvatore"(IEOS), National Research Council (CNR), 80131, Naples, Italy
| | - Stefano De Tito
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK. The Study Has Been Previously Performed at IEOS-CNR, Naples, Italy
| | - Matteo Lo Monte
- Institute of Experimental Endocrinology and Oncology "G. Salvatore"(IEOS), National Research Council (CNR), 80131, Naples, Italy
| | - Rosario Oliva
- Department of Chemical Sciences, University of Naples Federico II, 80126, Naples, Italy
| | - Francesca Bruzzese
- Animal Facility Unit, Istituto Nazionale Tumori-IRCCS-Fondazione G. Pascale, 80131, Naples, Italy
| | - Maria Serena Roca
- Experimental Pharmacology Unit, Istituto Nazionale Tumori-IRCCS-Fondazione G. Pascale, Naples, 80131, Italy
| | - Antonella Zannetti
- Institute of Biostructures and Bioimaging (IBB), National Research Council (CNR), Naples, 80145, Italy
| | - Adelaide Greco
- Interdepartmental Service Center of Veterinary Radiology, University of Naples Federico II, 80137, Naples, Italy
| | - Daniela Spano
- Institute of Experimental Endocrinology and Oncology "G. Salvatore"(IEOS), National Research Council (CNR), 80131, Naples, Italy
| | - Inmaculada Ayala
- Institute of Experimental Endocrinology and Oncology "G. Salvatore"(IEOS), National Research Council (CNR), 80131, Naples, Italy
| | - Assunta Liberti
- National Research Council (CNR), Piazzale Aldo Moro, 700185, Rome, Italy
- Biology and Evolution of Marine Organisms (BEOM), Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Luigi Petraccone
- Department of Chemical Sciences, University of Naples Federico II, 80126, Naples, Italy
| | - Nina Dathan
- Institute of Experimental Endocrinology and Oncology "G. Salvatore"(IEOS), National Research Council (CNR), 80131, Naples, Italy
| | - Giuliana Catara
- Institute of Biochemistry and Cell Biology, National Research Council (CNR), 80131, Naples, Italy
| | - Laura Schembri
- National Research Council (CNR), Piazzale Aldo Moro, 700185, Rome, Italy
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy
| | - Antonino Colanzi
- Institute of Experimental Endocrinology and Oncology "G. Salvatore"(IEOS), National Research Council (CNR), 80131, Naples, Italy
| | - Alfredo Budillon
- Scientific Directorate, Istituto Nazionale Tumori-IRCCS-Fondazione G. Pascale, 80131, Naples, Italy
| | | | - Pompea Del Vecchio
- Department of Chemical Sciences, University of Naples Federico II, 80126, Naples, Italy
| | - Alberto Luini
- Institute of Experimental Endocrinology and Oncology "G. Salvatore"(IEOS), National Research Council (CNR), 80131, Naples, Italy
| | - Daniela Corda
- Institute of Experimental Endocrinology and Oncology "G. Salvatore"(IEOS), National Research Council (CNR), 80131, Naples, Italy.
| | - Carmen Valente
- Institute of Experimental Endocrinology and Oncology "G. Salvatore"(IEOS), National Research Council (CNR), 80131, Naples, Italy.
- Present address: Dompé Farmaceutici S.P.A, L'Aquila, Italy.
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2
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Wu-Baer F, Wong M, Tschoe L, Lin CS, Jiang W, Zha S, Baer R. ATM/ATR Phosphorylation of CtIP on Its Conserved Sae2-like Domain Is Required for Genotoxin-Induced DNA Resection but Dispensable for Animal Development. Cells 2023; 12:2762. [PMID: 38067190 PMCID: PMC10706839 DOI: 10.3390/cells12232762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/09/2023] [Accepted: 12/01/2023] [Indexed: 12/18/2023] Open
Abstract
Homology-directed repair (HDR) of double-strand DNA breaks (DSBs) is dependent on enzymatic resection of DNA ends by the Mre11/Rad50/Nbs1 complex. DNA resection is triggered by the CtIP/Sae2 protein, which allosterically promotes Mre11-mediated endonuclease DNA cleavage at a position internal to the DSB. Although the mechanics of resection, including the initial endonucleolytic step, are largely conserved in eucaryotes, CtIP and its functional counterpart in Saccharomyces cerevisiae (Sae2) share only a modest stretch of amino acid homology. Nonetheless, this stretch contains two highly conserved phosphorylation sites for cyclin-dependent kinases (T843 in mouse) and the damage-induced ATM/ATR kinases (T855 in mouse), both of which are required for DNA resection. To explore the function of ATM/ATR phosphorylation at Ctip-T855, we generated and analyzed mice expressing the Ctip-T855A mutant. Surprisingly, unlike Ctip-null mice and Ctip-T843A-expressing mice, both of which undergo embryonic lethality, homozygous CtipT855A/T855A mice develop normally. Nonetheless, they are hypersensitive to ionizing radiation, and CtipT855A/T855A mouse embryo fibroblasts from these mice display marked defects in DNA resection, chromosomal stability, and HDR-mediated repair of DSBs. Thus, although ATM/ATR phosphorylation of CtIP-T855 is not required for normal animal development, it enhances CtIP-mediated DNA resection in response to acute stress, such as genotoxin exposure.
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Affiliation(s)
- Foon Wu-Baer
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
| | - Madeline Wong
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
| | - Lydia Tschoe
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
| | - Chyuan-Sheng Lin
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wenxia Jiang
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Shan Zha
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Richard Baer
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
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3
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Bai W, Zhao B, Gu M, Dong J. Alternative end-joining in BCR gene rearrangements and translocations. Acta Biochim Biophys Sin (Shanghai) 2022; 54:782-795. [PMID: 35593472 PMCID: PMC9828324 DOI: 10.3724/abbs.2022051] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Programmed DNA double-strand breaks (DSBs) occur during antigen receptor gene recombination, namely V(D)J recombination in developing B lymphocytes and class switch recombination (CSR) in mature B cells. Repair of these DSBs by classical end-joining (c-NHEJ) enables the generation of diverse BCR repertoires for efficient humoral immunity. Deletion of or mutation in c-NHEJ genes in mice and humans confer various degrees of primary immune deficiency and predisposition to lymphoid malignancies that often harbor oncogenic chromosomal translocations. In the absence of c-NHEJ, alternative end-joining (A-EJ) catalyzes robust CSR and to a much lesser extent, V(D)J recombination, but the mechanisms of A-EJ are only poorly defined. In this review, we introduce recent advances in the understanding of A-EJ in the context of V(D)J recombination and CSR with emphases on DSB end processing, DNA polymerases and ligases, and discuss the implications of A-EJ to lymphoid development and chromosomal translocations.
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Affiliation(s)
- Wanyu Bai
- Department of ImmunologyZhongshan School of MedicineSun Yat-sen UniversityGuangzhou510080China,Key Laboratory of Tropical Disease Control (Sun Yat-sen University)Ministry of EducationGuangzhou510080China
| | - Bo Zhao
- Department of ImmunologyZhongshan School of MedicineSun Yat-sen UniversityGuangzhou510080China,Key Laboratory of Tropical Disease Control (Sun Yat-sen University)Ministry of EducationGuangzhou510080China
| | - Mingyu Gu
- Department of ImmunologyZhongshan School of MedicineSun Yat-sen UniversityGuangzhou510080China,Key Laboratory of Tropical Disease Control (Sun Yat-sen University)Ministry of EducationGuangzhou510080China
| | - Junchao Dong
- Department of ImmunologyZhongshan School of MedicineSun Yat-sen UniversityGuangzhou510080China,Key Laboratory of Tropical Disease Control (Sun Yat-sen University)Ministry of EducationGuangzhou510080China,Correspondence address. Tel: +86-20-87330571; E-mail:
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4
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Lin X, Jiang W, Rudolph J, Lee BJ, Luger K, Zha S. PARP inhibitors trap PARP2 and alter the mode of recruitment of PARP2 at DNA damage sites. Nucleic Acids Res 2022; 50:3958-3973. [PMID: 35349716 PMCID: PMC9023293 DOI: 10.1093/nar/gkac188] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/24/2022] [Accepted: 03/23/2022] [Indexed: 12/11/2022] Open
Abstract
Dual-inhibitors of PARP1 and PARP2 are promising anti-cancer drugs. In addition to blocking PARP1&2 enzymatic activity, PARP inhibitors also extend the lifetime of DNA damage-induced PARP1&2 foci, termed trapping. Trapping is important for the therapeutic effects of PARP inhibitors. Using live-cell imaging, we found that PARP inhibitors cause persistent PARP2 foci by switching the mode of PARP2 recruitment from a predominantly PARP1- and PAR-dependent rapid exchange to a WGR domain-mediated stalling of PARP2 on DNA. Specifically, PARP1-deletion markedly reduces but does not abolish PARP2 foci. The residual PARP2 foci in PARP1-deficient cells are DNA-dependent and abrogated by the R140A mutation in the WGR domain. Yet, PARP2-R140A forms normal foci in PARP1-proficient cells. In PARP1-deficient cells, PARP inhibitors - niraparib, talazoparib, and, to a lesser extent, olaparib - enhance PARP2 foci by preventing PARP2 exchange. This trapping of PARP2 is independent of auto-PARylation and is abolished by the R140A mutation in the WGR domain and the H415A mutation in the catalytic domain. Taken together, we found that PARP inhibitors trap PARP2 by physically stalling PARP2 on DNA via the WGR-DNA interaction while suppressing the PARP1- and PAR-dependent rapid exchange of PARP2.
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Affiliation(s)
- Xiaohui Lin
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY10032, USA
| | - Wenxia Jiang
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY10032, USA
| | - Johannes Rudolph
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO80309, USA
| | - Brian J Lee
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY10032, USA
| | - Karolin Luger
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO80309, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO80309, USA
| | - Shan Zha
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY10032, USA
- Department of Pathology and Cell Biology, Herbert Irvine Comprehensive Cancer Center, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY10032, USA
- Division of Pediatric Hematology, Oncology and Stem Cell Transplantation, Department of Pediatrics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY10032, USA
- Department of Immunology and Microbiology, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY10032, USA
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5
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Sun X, Bai J, Xu J, Xi X, Gu M, Zhu C, Xue H, Chen C, Dong J. Multiple DSB Resection Activities Redundantly Promote Alternative End Joining-Mediated Class Switch Recombination. Front Cell Dev Biol 2021; 9:767624. [PMID: 34926456 PMCID: PMC8671047 DOI: 10.3389/fcell.2021.767624] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/25/2021] [Indexed: 01/13/2023] Open
Abstract
Alternative end joining (A-EJ) catalyzes substantial level of antibody class switch recombination (CSR) in B cells deficient for classical non-homologous end joining, featuring increased switch (S) region DSB resection and junctional microhomology (MH). While resection has been suggested to initiate A-EJ in model DSB repair systems using engineered endonucleases, the contribution of resection factors to A-EJ-mediated CSR remains unclear. In this study, we systematically dissected the requirement for individual DSB resection factors in A-EJ-mediated class switching with a cell-based assay system and high-throughput sequencing. We show that while CtIP and Mre11 both are mildly required for CSR in WT cells, they play more critical roles in mediating A-EJ CSR, which depend on the exonuclease activity of Mre11. While DNA2 and the helicase/HRDC domain of BLM are required for A-EJ by mediating long S region DSB resection, in contrast, Exo1's resection-related function does not play any obvious roles for class switching in either c-NHEJ or A-EJ cells, or mediated in an AID-independent manner by joining of Cas9 breaks. Furthermore, ATM and its kinase activity functions at least in part independent of CtIP/Mre11 to mediate A-EJ switching in Lig4-deficient cells. In stark contrast to Lig4 deficiency, 53BP1-deficient cells do not depend on ATM/Mre11/CtIP for residual joining. We discuss the roles for each resection factor in A-EJ-mediated CSR and suggest that the extent of requirements for resection is context dependent.
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Affiliation(s)
- Xikui Sun
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Jingning Bai
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Jiejie Xu
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Xiaoli Xi
- Department of Gastroenterology, the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Mingyu Gu
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Chengming Zhu
- Research Center of the Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Hongman Xue
- Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-Sen University, Shenzhen, China
| | - Chun Chen
- Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-Sen University, Shenzhen, China
| | - Junchao Dong
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China.,Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-Sen University, Shenzhen, China
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6
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Wang XS, Menolfi D, Wu-Baer F, Fangazio M, Meyer SN, Shao Z, Wang Y, Zhu Y, Lee BJ, Estes VM, Cupo OM, Gautier J, Pasqualucci L, Dalla-Favera R, Baer R, Zha S. DNA damage-induced phosphorylation of CtIP at a conserved ATM/ATR site T855 promotes lymphomagenesis in mice. Proc Natl Acad Sci U S A 2021; 118:e2105440118. [PMID: 34521752 PMCID: PMC8463888 DOI: 10.1073/pnas.2105440118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2021] [Indexed: 12/28/2022] Open
Abstract
CtIP is a DNA end resection factor widely implicated in alternative end-joining (A-EJ)-mediated translocations in cell-based reporter systems. To address the physiological role of CtIP, an essential gene, in translocation-mediated lymphomagenesis, we introduced the T855A mutation at murine CtIP to nonhomologous end-joining and Tp53 double-deficient mice that routinely succumbed to lymphomas carrying A-EJ-mediated IgH-Myc translocations. T855 of CtIP is phosphorylated by ATM or ATR kinases upon DNA damage to promote end resection. Here, we reported that the T855A mutation of CtIP compromised the neonatal development of Xrcc4-/-Tp53-/- mice and the IgH-Myc translocation-driven lymphomagenesis in DNA-PKcs-/-Tp53-/- mice. Mechanistically, the T855A mutation limits DNA end resection length without affecting hairpin opening, translocation frequency, or fork stability. Meanwhile, after radiation, CtIP-T855A mutant cells showed a consistent decreased Chk1 phosphorylation and defects in the G2/M cell cycle checkpoint. Consistent with the role of T855A mutation in lymphomagenesis beyond translocation, the CtIP-T855A mutation also delays splenomegaly in λ-Myc mice. Collectively, our study revealed a role of CtIP-T855 phosphorylation in lymphomagenesis beyond A-EJ-mediated chromosomal translocation.
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Affiliation(s)
- Xiaobin S Wang
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
- Graduate Program of Pathobiology and Molecular Medicine, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Demis Menolfi
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Foon Wu-Baer
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Marco Fangazio
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Stefanie N Meyer
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Zhengping Shao
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Yunyue Wang
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Yimeng Zhu
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Brian J Lee
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Verna M Estes
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Olivia M Cupo
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
| | - Jean Gautier
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
- Department of Genetics and Development, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Laura Pasqualucci
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
- Department of Pathology and Cell Biology, Herbert Irving Comprehensive Cancer Center, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Riccardo Dalla-Favera
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
- Department of Genetics and Development, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
- Department of Pathology and Cell Biology, Herbert Irving Comprehensive Cancer Center, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
- Department of Immunology and Microbiology, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Richard Baer
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032
- Department of Pathology and Cell Biology, Herbert Irving Comprehensive Cancer Center, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Shan Zha
- Institute for Cancer Genetics, Vagelos College for Physicians and Surgeons, Columbia University, New York City, NY 10032;
- Department of Pathology and Cell Biology, Herbert Irving Comprehensive Cancer Center, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
- Department of Immunology and Microbiology, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
- Division of Pediatric Hematology, Oncology and Stem Cell Transplantation, Department of Pediatrics, Vagelos College for Physicians and Surgeons, Columbia University, New York, NY 10032
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7
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Milanovic M, Shao Z, Estes VM, Wang XS, Menolfi D, Lin X, Lee BJ, Xu J, Cupo OM, Wang D, Zha S. FATC Domain Deletion Compromises ATM Protein Stability, Blocks Lymphocyte Development, and Promotes Lymphomagenesis. THE JOURNAL OF IMMUNOLOGY 2021; 206:1228-1239. [PMID: 33536256 DOI: 10.4049/jimmunol.2000967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 01/04/2021] [Indexed: 12/21/2022]
Abstract
Ataxia-telangiectasia mutated (ATM) kinase is a master regulator of the DNA damage response, and loss of ATM leads to primary immunodeficiency and greatly increased risk for lymphoid malignancies. The FATC domain is conserved in phosphatidylinositol-3-kinase-related protein kinases (PIKKs). Truncation mutation in the FATC domain (R3047X) selectively compromised reactive oxygen species-induced ATM activation in cell-free assays. In this article, we show that in mouse models, knock-in ATM-R3057X mutation (Atm RX , corresponding to R3047X in human ATM) severely compromises ATM protein stability and causes T cell developmental defects, B cell Ig class-switch recombination defects, and infertility resembling ATM-null. The residual ATM-R3057X protein retains minimal yet functional measurable DNA damage-induced checkpoint activation and significantly delays lymphomagenesis in Atm RX/RX mice compared with Atm -/- . Together, these results support a physiological role of the FATC domain in ATM protein stability and show that the presence of minimal residual ATM-R3057X protein can prevent growth retardation and delay tumorigenesis without restoring lymphocyte development and fertility.
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Affiliation(s)
- Maja Milanovic
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Zhengping Shao
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Verna M Estes
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Xiaobin S Wang
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Demis Menolfi
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Xiaohui Lin
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Brian J Lee
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Jun Xu
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - Olivia M Cupo
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Dong Wang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - Shan Zha
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032; .,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032.,Division of Pediatric Oncology, Hematology and Stem Cell Transplantation, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032; and.,Department of Immunology and Microbiology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
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8
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Milanovic M, Sprinzen L, Menolfi D, Lee JH, Yamamoto K, Li Y, Lee BJ, Xu J, Estes VM, Wang D, Mckinnon PJ, Paull TT, Zha S. The Cancer-Associated ATM R3008H Mutation Reveals the Link between ATM Activation and Its Exchange. Cancer Res 2021; 81:426-437. [PMID: 33239428 PMCID: PMC8137556 DOI: 10.1158/0008-5472.can-20-2447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/14/2020] [Accepted: 11/18/2020] [Indexed: 11/16/2022]
Abstract
ATM kinase is a tumor suppressor and a master regulator of the DNA damage response. Most cancer-associated alterations to ATM are missense mutations at the PI3-kinase regulatory domain (PRD) or the kinase domain. Expression of kinase-dead (KD) ATM protein solely accelerates lymphomagenesis beyond ATM loss. To understand how PRD suppresses lymphomagenesis, we introduced the cancer-associated PRD mutation R3008H (R3016 in mouse) into mice. R3008H abrogated DNA damage- and oxidative stress-induced activation of ATM without consistently affecting ATM protein stability and recruitment. In contrast to the early embryonic lethality of AtmKD/KD mice, AtmR3016H (AtmR/R ) mice were viable, immunodeficient, and displayed spontaneous craniofacial abnormalities and delayed lymphomagenesis compared with Atm-/- controls. Mechanistically, R3008H rescued the tardy exchange of ATM-KD at DNA damage foci, indicating that PRD coordinates ATM activation with its exchange at DNA-breaks. Taken together, our results reveal a unique tumorigenesis profile for PRD mutations that is distinct from null or KD mutations. SIGNIFICANT: This study functionally characterizes the most common ATM missense mutation R3008H in cancer and identifies a unique role of PI3-kinase regulatory domain in ATM activation.
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Affiliation(s)
- Maja Milanovic
- Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York City, New York
| | - Lisa Sprinzen
- Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York City, New York
- Department of Pathology and Cell Biology, Pathobiology and Human Disease Graduate Program, Vagelos College for Physicians and Surgeons, Columbia University, New York, New York
| | - Demis Menolfi
- Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York City, New York
| | - Ji-Hoon Lee
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas
| | - Kenta Yamamoto
- Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York City, New York
- Department of Pathology and Cell Biology, Pathobiology and Human Disease Graduate Program, Vagelos College for Physicians and Surgeons, Columbia University, New York, New York
| | - Yang Li
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Brian J Lee
- Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York City, New York
| | - Jun Xu
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California
| | - Verna M Estes
- Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York City, New York
| | - Dong Wang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California
| | - Peter J Mckinnon
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Tanya T Paull
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas
| | - Shan Zha
- Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York City, New York.
- Division of Pediatric Oncology, Hematology and Stem Cell Transplantation, Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York City, New York
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9
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Saha T, Sundaravinayagam D, Di Virgilio M. Charting a DNA Repair Roadmap for Immunoglobulin Class Switch Recombination. Trends Biochem Sci 2020; 46:184-199. [PMID: 33250286 DOI: 10.1016/j.tibs.2020.10.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/08/2020] [Accepted: 10/23/2020] [Indexed: 01/18/2023]
Abstract
Immunoglobulin (Ig) class switch recombination (CSR) is the process occurring in mature B cells that diversifies the effector component of antibody responses. CSR is initiated by the activity of the B cell-specific enzyme activation-induced cytidine deaminase (AID), which leads to the formation of programmed DNA double-strand breaks (DSBs) at the Ig heavy chain (Igh) locus. Mature B cells use a multilayered and complex regulatory framework to ensure that AID-induced DNA breaks are channeled into productive repair reactions leading to CSR, and to avoid aberrant repair events causing lymphomagenic chromosomal translocations. Here, we review the DNA repair pathways acting on AID-induced DSBs and their functional interplay, with a particular focus on the latest developments in their molecular composition and mechanistic regulation.
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Affiliation(s)
- Tannishtha Saha
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
| | - Devakumar Sundaravinayagam
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany.
| | - Michela Di Virgilio
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany; Charité-Universitätsmedizin Berlin, Berlin 10117, Germany.
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10
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CtIP-mediated DNA resection is dispensable for IgH class switch recombination by alternative end-joining. Proc Natl Acad Sci U S A 2020; 117:25700-25711. [PMID: 32989150 DOI: 10.1073/pnas.2010972117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
To generate antibodies with different effector functions, B cells undergo Immunoglobulin Heavy Chain (IgH) class switch recombination (CSR). The ligation step of CSR is usually mediated by the classical nonhomologous end-joining (cNHEJ) pathway. In cNHEJ-deficient cells, a remarkable ∼25% of CSR can be achieved by the alternative end-joining (Alt-EJ) pathway that preferentially uses microhomology (MH) at the junctions. While A-EJ-mediated repair of endonuclease-generated breaks requires DNA end resection, we show that CtIP-mediated DNA end resection is dispensable for A-EJ-mediated CSR using cNHEJ-deficient B cells. High-throughput sequencing analyses revealed that loss of ATM/ATR phosphorylation of CtIP at T855 or ATM kinase inhibition suppresses resection without altering the MH pattern of the A-EJ-mediated switch junctions. Moreover, we found that ATM kinase promotes Alt-EJ-mediated CSR by suppressing interchromosomal translocations independent of end resection. Finally, temporal analyses reveal that MHs are enriched in early internal deletions even in cNHEJ-proficient B cells. Thus, we propose that repetitive IgH switch regions represent favored substrates for MH-mediated end-joining contributing to the robustness and resection independence of A-EJ-mediated CSR.
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11
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Reginato G, Cejka P. The MRE11 complex: A versatile toolkit for the repair of broken DNA. DNA Repair (Amst) 2020; 91-92:102869. [PMID: 32480356 DOI: 10.1016/j.dnarep.2020.102869] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 12/13/2022]
Abstract
When DNA breaks, the ends need to be stabilized and processed to facilitate subsequent repair, which can occur by either direct but error-prone end-joining with another broken DNA molecule or a more accurate homology-directed repair by the recombination machinery. At the same time, the presence of broken DNA triggers a signaling cascade that regulates the repair events and cellular progression through the cell cycle. The MRE11 nuclease, together with RAD50 and NBS1 forms a complex termed MRN that participates in all these processes. Although MRE11 was first identified more than 20 years ago, deep insights into its mechanism of action and regulation are much more recent. Here we review how MRE11 functions within MRN, and how the complex is further regulated by CtIP and its phosphorylation in a cell cycle dependent manner. We describe how RAD50, NBS1 and CtIP convert MRE11, exhibiting per se a 3'→5' exonuclease activity, into an ensemble that instead degrades primarily the 5'-terminated strand by endonucleolytic cleavage at DNA break sites to generate 3' overhangs, as required for the initiation of homologous recombination. The unique mechanism of DNA end resection by MRN-CtIP makes it a very flexible toolkit to process DNA breaks with a variety of secondary structures and protein blocks. Such a block can also be the Ku heterodimer, and emerging evidence suggests that MRN-CtIP may often need to remove Ku from DNA ends before initiating homologous recombination. Misregulation of DNA break repair results in mutations and chromosome rearrangements that can drive cancer development. Therefore, a detailed understanding of the underlying processes is highly relevant for human health.
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Affiliation(s)
- Giordano Reginato
- Institute for Research in Biomedicine, Università della Svizzera Italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera Italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland.
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12
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Wang XS, Lee BJ, Zha S. The recent advances in non-homologous end-joining through the lens of lymphocyte development. DNA Repair (Amst) 2020; 94:102874. [PMID: 32623318 DOI: 10.1016/j.dnarep.2020.102874] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/16/2020] [Accepted: 05/24/2020] [Indexed: 12/17/2022]
Abstract
Lymphocyte development requires ordered assembly and subsequent modifications of the antigen receptor genes through V(D)J recombination and Immunoglobulin class switch recombination (CSR), respectively. While the programmed DNA cleavage events are initiated by lymphocyte-specific factors, the resulting DNA double-strand break (DSB) intermediates activate the ATM kinase-mediated DNA damage response (DDR) and rely on the ubiquitously expressed classical non-homologous end-joining (cNHEJ) pathway including the DNA-dependent protein kinase (DNA-PK), and, in the case of CSR, also the alternative end-joining (Alt-EJ) pathway, for repair. Correspondingly, patients and animal models with cNHEJ or DDR defects develop distinct types of immunodeficiency reflecting their specific DNA repair deficiency. The unique end-structure, sequence context, and cell cycle regulation of V(D)J recombination and CSR also provide a valuable platform to study the mechanisms of, and the interplay between, cNHEJ and DDR. Here, we compare and contrast the genetic consequences of DNA repair defects in V(D)J recombination and CSR with a focus on the newly discovered cNHEJ factors and the kinase-dependent structural roles of ATM and DNA-PK in animal models. Throughout, we try to highlight the pending questions and emerging differences that will extend our understanding of cNHEJ and DDR in the context of primary immunodeficiency and lymphoid malignancies.
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Affiliation(s)
- Xiaobin S Wang
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Graduate Program of Pathobiology and Molecular Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Brian J Lee
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Shan Zha
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Immunology and Microbiology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States.
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13
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Yu TY, Garcia VE, Symington LS. CDK and Mec1/Tel1-catalyzed phosphorylation of Sae2 regulate different responses to DNA damage. Nucleic Acids Res 2020; 47:11238-11249. [PMID: 31552432 PMCID: PMC6868371 DOI: 10.1093/nar/gkz814] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 09/09/2019] [Accepted: 09/20/2019] [Indexed: 11/14/2022] Open
Abstract
Sae2 functions in the DNA damage response by controlling Mre11-Rad50-Xrs2 (MRX)-catalyzed end resection, an essential step for homology-dependent repair of double-strand breaks (DSBs), and by attenuating DNA damage checkpoint signaling. Phosphorylation of Sae2 by cyclin-dependent kinase (CDK1/Cdc28) activates the Mre11 endonuclease, while the physiological role of Sae2 phosphorylation by Mec1 and Tel1 checkpoint kinases is not fully understood. Here, we compare the phenotype of sae2 mutants lacking the main CDK (sae2-S267A) or Mec1 and Tel1 phosphorylation sites (sae2-5A) with sae2Δ and Mre11 nuclease defective (mre11-nd) mutants. The phosphorylation-site mutations confer DNA damage sensitivity, but not to the same extent as sae2Δ. The sae2-S267A mutation is epistatic to mre11-nd for camptothecin (CPT) sensitivity and synergizes with sgs1Δ, whereas sae2-5A synergizes with mre11-nd and exhibits epistasis with sgs1Δ. We find that attenuation of checkpoint signaling by Sae2 is mostly independent of Mre11 endonuclease activation but requires Mec1 and Tel1-dependent phosphorylation of Sae2. These results support a model whereby CDK-catalyzed phosphorylation of Sae2 activates resection via Mre11 endonuclease, whereas Sae2 phosphorylation by Mec1 and Tel1 promotes resection by the Dna2-Sgs1 and Exo1 pathways indirectly by dampening the DNA damage response.
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Affiliation(s)
- Tai-Yuan Yu
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Valerie E Garcia
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Lorraine S Symington
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA
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14
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Ceppi I, Howard SM, Kasaciunaite K, Pinto C, Anand R, Seidel R, Cejka P. CtIP promotes the motor activity of DNA2 to accelerate long-range DNA end resection. Proc Natl Acad Sci U S A 2020; 117:8859-8869. [PMID: 32241893 PMCID: PMC7183222 DOI: 10.1073/pnas.2001165117] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
To repair a DNA double-strand break by homologous recombination, 5'-terminated DNA strands must first be resected to reveal 3'-overhangs. This process is initiated by a short-range resection catalyzed by MRE11-RAD50-NBS1 (MRN) stimulated by CtIP, which is followed by a long-range step involving EXO1 or DNA2 nuclease. DNA2 is a bifunctional enzyme that contains both single-stranded DNA (ssDNA)-specific nuclease and motor activities. Upon DNA unwinding by Bloom (BLM) or Werner (WRN) helicase, RPA directs the DNA2 nuclease to degrade the 5'-strand. RPA bound to ssDNA also represents a barrier, explaining the need for the motor activity of DNA2 to displace RPA prior to resection. Using ensemble and single-molecule biochemistry, we show that CtIP also dramatically stimulates the adenosine 5'-triphosphate (ATP) hydrolysis-driven motor activity of DNA2 involved in the long-range resection step. This activation in turn strongly promotes the degradation of RPA-coated ssDNA by DNA2. Accordingly, the stimulatory effect of CtIP is only observed with wild-type DNA2, but not the helicase-deficient variant. Similarly to the function of CtIP to promote MRN, also the DNA2 stimulatory effect is facilitated by CtIP phosphorylation. The domain of CtIP required to promote DNA2 is located in the central region lacking in lower eukaryotes and is fully separable from domains involved in the stimulation of MRN. These results establish how CtIP couples both MRE11-dependent short-range and DNA2-dependent long-range resection and define the involvement of the motor activity of DNA2 in this process. Our data might help explain the less severe resection defects of MRE11 nuclease-deficient cells compared to those lacking CtIP.
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Affiliation(s)
- Ilaria Ceppi
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Bellinzona, 6500, Switzerland
- Institute of Biochemistry, Department of Biology, ETH, Zürich, 8093, Switzerland
| | - Sean M Howard
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Bellinzona, 6500, Switzerland
| | - Kristina Kasaciunaite
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, 04103, Germany
| | - Cosimo Pinto
- Institute of Molecular Cancer Research, University of Zürich, Zürich, 8057, Switzerland
| | - Roopesh Anand
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Bellinzona, 6500, Switzerland
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, 04103, Germany
| | - Petr Cejka
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Bellinzona, 6500, Switzerland;
- Institute of Biochemistry, Department of Biology, ETH, Zürich, 8093, Switzerland
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