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Oram MK, Baxley RM, Simon EM, Lin K, Chang YC, Wang L, Myers CL, Bielinsky AK. RNF4 prevents genomic instability caused by chronic DNA under-replication. DNA Repair (Amst) 2024; 135:103646. [PMID: 38340377 PMCID: PMC10948022 DOI: 10.1016/j.dnarep.2024.103646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/26/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
Eukaryotic genome stability is maintained by a complex and diverse set of molecular processes. One class of enzymes that promotes proper DNA repair, replication and cell cycle progression comprises small ubiquitin-like modifier (SUMO)-targeted E3 ligases, or STUbLs. Previously, we reported a role for the budding yeast STUbL synthetically lethal with sgs1 (Slx) 5/8 in preventing G2/M-phase arrest in a minichromosome maintenance protein 10 (Mcm10)-deficient model of replication stress. Here, we extend these studies to human cells, examining the requirement for the human STUbL RING finger protein 4 (RNF4) in MCM10 mutant cancer cells. We find that MCM10 and RNF4 independently promote origin firing but regulate DNA synthesis epistatically and, unlike in yeast, the negative genetic interaction between RNF4 and MCM10 causes cells to accumulate in G1-phase. When MCM10 is deficient, RNF4 prevents excessive DNA under-replication at hard-to-replicate regions that results in large DNA copy number alterations and severely reduced viability. Overall, our findings highlight that STUbLs participate in species-specific mechanisms to maintain genome stability, and that human RNF4 is required for origin activation in the presence of chronic replication stress.
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Affiliation(s)
- Marissa K Oram
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ryan M Baxley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Emily M Simon
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kevin Lin
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Department of Computer Science & Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ya-Chu Chang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Liangjun Wang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Chad L Myers
- Department of Computer Science & Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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2
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Lin K, Chang YC, Billmann M, Ward HN, Le K, Hassan AZ, Bhojoo U, Chan K, Costanzo M, Moffat J, Boone C, Bielinsky AK, Myers CL. A scalable platform for efficient CRISPR-Cas9 chemical-genetic screens of DNA damage-inducing compounds. Sci Rep 2024; 14:2508. [PMID: 38291084 PMCID: PMC10828508 DOI: 10.1038/s41598-024-51735-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 01/09/2024] [Indexed: 02/01/2024] Open
Abstract
Current approaches to define chemical-genetic interactions (CGIs) in human cell lines are resource-intensive. We designed a scalable chemical-genetic screening platform by generating a DNA damage response (DDR)-focused custom sgRNA library targeting 1011 genes with 3033 sgRNAs. We performed five proof-of-principle compound screens and found that the compounds' known modes-of-action (MoA) were enriched among the compounds' CGIs. These scalable screens recapitulated expected CGIs at a comparable signal-to-noise ratio (SNR) relative to genome-wide screens. Furthermore, time-resolved CGIs, captured by sequencing screens at various time points, suggested an unexpected, late interstrand-crosslinking (ICL) repair pathway response to camptothecin-induced DNA damage. Our approach can facilitate screening compounds at scale with 20-fold fewer resources than commonly used genome-wide libraries and produce biologically informative CGI profiles.
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Affiliation(s)
- Kevin Lin
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, Minneapolis, MN, USA
- Bioinformatics and Computational Biology Graduate Program, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Ya-Chu Chang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Maximilian Billmann
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, Minneapolis, MN, USA
- Institute of Human Genetics, University of Bonn, School of Medicine and University Hospital Bonn, Bonn, Germany
| | - Henry N Ward
- Bioinformatics and Computational Biology Graduate Program, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Khoi Le
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Arshia Z Hassan
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Urvi Bhojoo
- Donnelly Centre, University of Toronto, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Katherine Chan
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Michael Costanzo
- Donnelly Centre, University of Toronto, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Jason Moffat
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Institute for Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Charles Boone
- Donnelly Centre, University of Toronto, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota-Twin Cities, Minneapolis, MN, USA.
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA.
| | - Chad L Myers
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, Minneapolis, MN, USA.
- Bioinformatics and Computational Biology Graduate Program, University of Minnesota-Twin Cities, Minneapolis, MN, USA.
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3
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Schmit MM, Baxley RM, Wang L, Hinderlie P, Kaufman M, Simon E, Raju A, Miller JS, Bielinsky AK. A critical threshold of MCM10 is required to maintain genome stability during differentiation of induced pluripotent stem cells into natural killer cells. Open Biol 2024; 14:230407. [PMID: 38262603 PMCID: PMC10805602 DOI: 10.1098/rsob.230407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 11/23/2023] [Indexed: 01/25/2024] Open
Abstract
Natural killer (NK) cell deficiency (NKD) is a rare disease in which NK cell function is reduced, leaving affected individuals susceptible to repeated viral infections and cancer. Recently, a patient with NKD was identified carrying compound heterozygous variants of MCM10 (minichromosome maintenance protein 10), an essential gene required for DNA replication, that caused a significant decrease in the amount of functional MCM10. NKD in this patient presented as loss of functionally mature late-stage NK cells. To understand how MCM10 deficiency affects NK cell development, we generated MCM10 heterozygous (MCM10+/-) induced pluripotent stem cell (iPSC) lines. Analyses of these cell lines demonstrated that MCM10 was haploinsufficient, similar to results in other human cell lines. Reduced levels of MCM10 in mutant iPSCs was associated with impaired clonogenic survival and increased genomic instability, including micronuclei formation and telomere erosion. The severity of these phenotypes correlated with the extent of MCM10 depletion. Significantly, MCM10+/- iPSCs displayed defects in NK cell differentiation, exhibiting reduced yields of hematopoietic stem cells (HSCs). Although MCM10+/- HSCs were able to give rise to lymphoid progenitors, these did not generate mature NK cells. The lack of mature NK cells coincided with telomere erosion, suggesting that NKD caused by these MCM10 variants arose from the accumulation of genomic instability including degradation of chromosome ends.
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Affiliation(s)
- Megan M. Schmit
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Ryan M. Baxley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Liangjun Wang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Peter Hinderlie
- Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, USA
| | - Marissa Kaufman
- Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, USA
| | - Emily Simon
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Anjali Raju
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Jeffrey S. Miller
- Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
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4
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Leung W, Baxley RM, Traband E, Chang YC, Rogers CB, Wang L, Durrett W, Bromley KS, Fiedorowicz L, Thakar T, Tella A, Sobeck A, Hendrickson EA, Moldovan GL, Shima N, Bielinsky AK. FANCD2-dependent mitotic DNA synthesis relies on PCNA K164 ubiquitination. Cell Rep 2023; 42:113523. [PMID: 38060446 PMCID: PMC10842461 DOI: 10.1016/j.celrep.2023.113523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/09/2023] [Accepted: 11/15/2023] [Indexed: 12/30/2023] Open
Abstract
Ubiquitination of proliferating cell nuclear antigen (PCNA) at lysine 164 (K164) activates DNA damage tolerance pathways. Currently, we lack a comprehensive understanding of how PCNA K164 ubiquitination promotes genome stability. To evaluate this, we generated stable cell lines expressing PCNAK164R from the endogenous PCNA locus. Our data reveal that the inability to ubiquitinate K164 causes perturbations in global DNA replication. Persistent replication stress generates under-replicated regions and is exacerbated by the DNA polymerase inhibitor aphidicolin. We show that these phenotypes are due, in part, to impaired Fanconi anemia group D2 protein (FANCD2)-dependent mitotic DNA synthesis (MiDAS) in PCNAK164R cells. FANCD2 mono-ubiquitination is significantly reduced in PCNAK164R mutants, leading to reduced chromatin association and foci formation, both prerequisites for FANCD2-dependent MiDAS. Furthermore, K164 ubiquitination coordinates direct PCNA/FANCD2 colocalization in mitotic nuclei. Here, we show that PCNA K164 ubiquitination maintains human genome stability by promoting FANCD2-dependent MiDAS to prevent the accumulation of under-replicated DNA.
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Affiliation(s)
- Wendy Leung
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ryan M Baxley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Emma Traband
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ya-Chu Chang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Colette B Rogers
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Liangjun Wang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Wesley Durrett
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kendall S Bromley
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Lidia Fiedorowicz
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Tanay Thakar
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Anika Tella
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alexandra Sobeck
- Institute for Human Genetics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Eric A Hendrickson
- Department of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Naoko Shima
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA.
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5
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Chang YC, Lin K, Baxley RM, Durrett W, Wang L, Stojkova O, Billmann M, Ward H, Myers CL, Bielinsky AK. RNF4 and USP7 cooperate in ubiquitin-regulated steps of DNA replication. Open Biol 2023; 13:230068. [PMID: 37607592 PMCID: PMC10444366 DOI: 10.1098/rsob.230068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 07/27/2023] [Indexed: 08/24/2023] Open
Abstract
DNA replication requires precise regulation achieved through post-translational modifications, including ubiquitination and SUMOylation. These modifications are linked by the SUMO-targeted E3 ubiquitin ligases (STUbLs). Ring finger protein 4 (RNF4), one of only two mammalian STUbLs, participates in double-strand break repair and resolving DNA-protein cross-links. However, its role in DNA replication has been poorly understood. Using CRISPR/Cas9 genetic screens, we discovered an unexpected dependency of RNF4 mutants on ubiquitin specific peptidase 7 (USP7) for survival in TP53-null retinal pigment epithelial cells. TP53-/-/RNF4-/-/USP7-/- triple knockout (TKO) cells displayed defects in DNA replication that cause genomic instability. These defects were exacerbated by the proteasome inhibitor bortezomib, which limited the nuclear ubiquitin pool. A shortage of free ubiquitin suppressed the ataxia telangiectasia and Rad3-related (ATR)-mediated checkpoint response, leading to increased cell death. In conclusion, RNF4 and USP7 work cooperatively to sustain a functional level of nuclear ubiquitin to maintain the integrity of the genome.
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Affiliation(s)
- Ya-Chu Chang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kevin Lin
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ryan M. Baxley
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Wesley Durrett
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Liangjun Wang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Olivera Stojkova
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Maximilian Billmann
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Henry Ward
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Chad L. Myers
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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6
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Rogers CB, Kram RE, Lin K, Myers CL, Sobeck A, Hendrickson EA, Bielinsky AK. Fanconi anemia-associated chromosomal radial formation is dependent on POLθ-mediated alternative end joining. Cell Rep 2023; 42:112428. [PMID: 37086407 DOI: 10.1016/j.celrep.2023.112428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 01/25/2023] [Accepted: 04/07/2023] [Indexed: 04/23/2023] Open
Abstract
Activation of the Fanconi anemia (FA) pathway after treatment with mitomycin C (MMC) is essential for preventing chromosome translocations termed "radials." When replication forks stall at MMC-induced interstrand crosslinks (ICLs), the FA pathway is activated to orchestrate ICL unhooking and repair of the DNA break intermediates. However, in FA-deficient cells, how ICL-associated breaks are resolved in a manner that leads to radials is unclear. Here, we demonstrate that MMC-induced radials are dependent on DNA polymerase theta (POLθ)-mediated alternative end joining (A-EJ). Specifically, we show that radials observed in FANCD2-/- cells are dependent on POLθ and DNA ligase III and occur independently of classical non-homologous end joining. Furthermore, treatment of FANCD2-/- cells with POLθ inhibitors abolishes radials and leads to the accumulation of breaks co-localizing with common fragile sites. Uniformly, these observations implicate A-EJ in radial formation and provide mechanistic insights into the treatment of FA pathway-deficient cancers with POLθ inhibitors.
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Affiliation(s)
- Colette B Rogers
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Rachel E Kram
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kevin Lin
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Chad L Myers
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alexandra Sobeck
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Eric A Hendrickson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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7
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Grange LJ, Reynolds JJ, Ullah F, Isidor B, Shearer RF, Latypova X, Baxley RM, Oliver AW, Ganesh A, Cooke SL, Jhujh SS, McNee GS, Hollingworth R, Higgs MR, Natsume T, Khan T, Martos-Moreno GÁ, Chupp S, Mathew CG, Parry D, Simpson MA, Nahavandi N, Yüksel Z, Drasdo M, Kron A, Vogt P, Jonasson A, Seth SA, Gonzaga-Jauregui C, Brigatti KW, Stegmann APA, Kanemaki M, Josifova D, Uchiyama Y, Oh Y, Morimoto A, Osaka H, Ammous Z, Argente J, Matsumoto N, Stumpel CTRM, Taylor AMR, Jackson AP, Bielinsky AK, Mailand N, Le Caignec C, Davis EE, Stewart GS. Pathogenic variants in SLF2 and SMC5 cause segmented chromosomes and mosaic variegated hyperploidy. Nat Commun 2022; 13:6664. [PMID: 36333305 PMCID: PMC9636423 DOI: 10.1038/s41467-022-34349-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
Embryonic development is dictated by tight regulation of DNA replication, cell division and differentiation. Mutations in DNA repair and replication genes disrupt this equilibrium, giving rise to neurodevelopmental disease characterized by microcephaly, short stature and chromosomal breakage. Here, we identify biallelic variants in two components of the RAD18-SLF1/2-SMC5/6 genome stability pathway, SLF2 and SMC5, in 11 patients with microcephaly, short stature, cardiac abnormalities and anemia. Patient-derived cells exhibit a unique chromosomal instability phenotype consisting of segmented and dicentric chromosomes with mosaic variegated hyperploidy. To signify the importance of these segmented chromosomes, we have named this disorder Atelís (meaning - incomplete) Syndrome. Analysis of Atelís Syndrome cells reveals elevated levels of replication stress, partly due to a reduced ability to replicate through G-quadruplex DNA structures, and also loss of sister chromatid cohesion. Together, these data strengthen the functional link between SLF2 and the SMC5/6 complex, highlighting a distinct role for this pathway in maintaining genome stability.
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Affiliation(s)
- Laura J Grange
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - John J Reynolds
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Farid Ullah
- Advanced Center for Genetic and Translational Medicine (ACT-GeM), Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Chicago, IL, USA
- National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Bertrand Isidor
- Service de Génétique Médicale, CHU Nantes, Nantes Cedex 1, France
| | - Robert F Shearer
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Xenia Latypova
- Service de Génétique Médicale, CHU Nantes, Nantes Cedex 1, France
| | - Ryan M Baxley
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Antony W Oliver
- Genome Damage and Stability Centre, Science Park Road, University of Sussex, Falmer, Brighton, UK
| | - Anil Ganesh
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Sophie L Cooke
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Satpal S Jhujh
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Gavin S McNee
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Robert Hollingworth
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Martin R Higgs
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Toyoaki Natsume
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Mishima, Shizuoka, Japan
| | - Tahir Khan
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA
| | - Gabriel Á Martos-Moreno
- Hospital Infantil Universitario Niño Jesús, CIBER de fisiopatología de la obesidad y nutrición (CIBEROBN), Instituto de Salud Carlos III, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Christopher G Mathew
- Sydney Brenner Institute for Molecular Bioscience, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - David Parry
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, The University of Edinburgh, Edinburgh, Scotland
| | - Michael A Simpson
- Department of Medical and Molecular Genetics, Faculty of Life Science and Medicine, Guy's Hospital, King's College London, London, UK
| | - Nahid Nahavandi
- Bioscientia Institute for Medical Diagnostics, Human Genetics, Ingelheim, Germany
| | - Zafer Yüksel
- Bioscientia Institute for Medical Diagnostics, Human Genetics, Ingelheim, Germany
| | - Mojgan Drasdo
- Bioscientia Institute for Medical Diagnostics, Human Genetics, Ingelheim, Germany
| | - Anja Kron
- Bioscientia Institute for Medical Diagnostics, Human Genetics, Ingelheim, Germany
| | - Petra Vogt
- Bioscientia Institute for Medical Diagnostics, Human Genetics, Ingelheim, Germany
| | - Annemarie Jonasson
- Bioscientia Institute for Medical Diagnostics, Human Genetics, Ingelheim, Germany
| | | | - Claudia Gonzaga-Jauregui
- Regeneron Genetics Center, Regeneron Pharmaceuticals Inc., Tarrytown, NY, USA
- International Laboratory for Human Genome Research, Universidad Nacional Autónoma de México, Querétaro, México
| | | | - Alexander P A Stegmann
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Masato Kanemaki
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka, Japan
| | | | - Yuri Uchiyama
- Department of Rare Disease Genomics, Yokohama City University Hospital, Yokohama, Japan
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yukiko Oh
- Department of Paediatrics, Jichi Medical University School of Medicine, Tochigi, Japan
| | - Akira Morimoto
- Department of Paediatrics, Jichi Medical University School of Medicine, Tochigi, Japan
| | - Hitoshi Osaka
- Department of Paediatrics, Jichi Medical University School of Medicine, Tochigi, Japan
| | | | - Jesús Argente
- Hospital Infantil Universitario Niño Jesús, CIBER de fisiopatología de la obesidad y nutrición (CIBEROBN), Instituto de Salud Carlos III, Universidad Autónoma de Madrid, Madrid, Spain
- IMDEA Alimentación/IMDEA Food, Madrid, Spain
| | - Naomichi Matsumoto
- Department of Rare Disease Genomics, Yokohama City University Hospital, Yokohama, Japan
| | - Constance T R M Stumpel
- Department of Clinical Genetics and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Alexander M R Taylor
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Andrew P Jackson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, The University of Edinburgh, Edinburgh, Scotland
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Niels Mailand
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cedric Le Caignec
- Centre Hospitalier Universitaire Toulouse, Service de Génétique Médicale and ToNIC, Toulouse NeuroImaging Center, Inserm, UPS, Université de Toulouse, Toulouse, France.
| | - Erica E Davis
- Advanced Center for Genetic and Translational Medicine (ACT-GeM), Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Chicago, IL, USA.
- Department of Pediatrics; Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
| | - Grant S Stewart
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.
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8
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Kang Z, Fu P, Alcivar AL, Fu H, Redon C, Foo TK, Zuo Y, Ye C, Baxley R, Madireddy A, Buisson R, Bielinsky AK, Zou L, Shen Z, Aladjem MI, Xia B. BRCA2 associates with MCM10 to suppress PRIMPOL-mediated repriming and single-stranded gap formation after DNA damage. Nat Commun 2021; 12:5966. [PMID: 34645815 PMCID: PMC8514439 DOI: 10.1038/s41467-021-26227-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 09/23/2021] [Indexed: 11/28/2022] Open
Abstract
The BRCA2 tumor suppressor protects genome integrity by promoting homologous recombination-based repair of DNA breaks, stability of stalled DNA replication forks and DNA damage-induced cell cycle checkpoints. BRCA2 deficient cells display the radio-resistant DNA synthesis (RDS) phenotype, however the mechanism has remained elusive. Here we show that cells without BRCA2 are unable to sufficiently restrain DNA replication fork progression after DNA damage, and the underrestrained fork progression is due primarily to Primase-Polymerase (PRIMPOL)-mediated repriming of DNA synthesis downstream of lesions, leaving behind single-stranded DNA gaps. Moreover, we find that BRCA2 associates with the essential DNA replication factor MCM10 and this association suppresses PRIMPOL-mediated repriming and ssDNA gap formation, while having no impact on the stability of stalled replication forks. Our findings establish an important function for BRCA2, provide insights into replication fork control during the DNA damage response, and may have implications in tumor suppression and therapy response. Tumor suppressor BRCA2 is known to stabilize and restart stalled DNA replication forks. Here the authors show that BRCA2 is recruited to the replication fork through its interaction with MCM10 and inhibits Primase-Polymerase-mediated repriming, lesion bypass and single strand DNA gap formation after DNA damage.
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Affiliation(s)
- Zhihua Kang
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
| | - Pan Fu
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.,Department of Clinical Microbiology Laboratory, Children's Hospital of Fudan University, Shanghai, China
| | - Allen L Alcivar
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.,Bristol-Myers Squibb Company, Bloomsbury, NJ, 08804, USA
| | - Haiqing Fu
- Developmental Therapeutics Group, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Christophe Redon
- Developmental Therapeutics Group, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Tzeh Keong Foo
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
| | - Yamei Zuo
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
| | - Caiyong Ye
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.,School of Radiation Medicine and Protection, Soochow University, Suzhou, China
| | - Ryan Baxley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Advaitha Madireddy
- Department of Pediatric Hematology/Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
| | - Remi Buisson
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Boston, MA, USA.,Department of Biological Chemistry, University of California Irvine, Irvine, CA, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Boston, MA, USA
| | - Zhiyuan Shen
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
| | - Mirit I Aladjem
- Developmental Therapeutics Group, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Bing Xia
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.
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9
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Chang YC, Oram MK, Bielinsky AK. SUMO-Targeted Ubiquitin Ligases and Their Functions in Maintaining Genome Stability. Int J Mol Sci 2021; 22:ijms22105391. [PMID: 34065507 PMCID: PMC8161396 DOI: 10.3390/ijms22105391] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/14/2021] [Accepted: 05/16/2021] [Indexed: 02/06/2023] Open
Abstract
Small ubiquitin-like modifier (SUMO)-targeted E3 ubiquitin ligases (STUbLs) are specialized enzymes that recognize SUMOylated proteins and attach ubiquitin to them. They therefore connect the cellular SUMOylation and ubiquitination circuits. STUbLs participate in diverse molecular processes that span cell cycle regulated events, including DNA repair, replication, mitosis, and transcription. They operate during unperturbed conditions and in response to challenges, such as genotoxic stress. These E3 ubiquitin ligases modify their target substrates by catalyzing ubiquitin chains that form different linkages, resulting in proteolytic or non-proteolytic outcomes. Often, STUbLs function in compartmentalized environments, such as the nuclear envelope or kinetochore, and actively aid in nuclear relocalization of damaged DNA and stalled replication forks to promote DNA repair or fork restart. Furthermore, STUbLs reside in the same vicinity as SUMO proteases and deubiquitinases (DUBs), providing spatiotemporal control of their targets. In this review, we focus on the molecular mechanisms by which STUbLs help to maintain genome stability across different species.
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10
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Baxley RM, Leung W, Schmit MM, Matson JP, Yin L, Oram MK, Wang L, Taylor J, Hedberg J, Rogers CB, Harvey AJ, Basu D, Taylor JC, Pagnamenta AT, Dreau H, Craft J, Ormondroyd E, Watkins H, Hendrickson EA, Mace EM, Orange JS, Aihara H, Stewart GS, Blair E, Cook JG, Bielinsky AK. Bi-allelic MCM10 variants associated with immune dysfunction and cardiomyopathy cause telomere shortening. Nat Commun 2021; 12:1626. [PMID: 33712616 PMCID: PMC7955084 DOI: 10.1038/s41467-021-21878-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 02/11/2021] [Indexed: 12/22/2022] Open
Abstract
Minichromosome maintenance protein 10 (MCM10) is essential for eukaryotic DNA replication. Here, we describe compound heterozygous MCM10 variants in patients with distinctive, but overlapping, clinical phenotypes: natural killer (NK) cell deficiency (NKD) and restrictive cardiomyopathy (RCM) with hypoplasia of the spleen and thymus. To understand the mechanism of MCM10-associated disease, we modeled these variants in human cell lines. MCM10 deficiency causes chronic replication stress that reduces cell viability due to increased genomic instability and telomere erosion. Our data suggest that loss of MCM10 function constrains telomerase activity by accumulating abnormal replication fork structures enriched with single-stranded DNA. Terminally-arrested replication forks in MCM10-deficient cells require endonucleolytic processing by MUS81, as MCM10:MUS81 double mutants display decreased viability and accelerated telomere shortening. We propose that these bi-allelic variants in MCM10 predispose specific cardiac and immune cell lineages to prematurely arrest during differentiation, causing the clinical phenotypes observed in both NKD and RCM patients.
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Affiliation(s)
- Ryan M Baxley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Wendy Leung
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Megan M Schmit
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jacob Peter Matson
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Lulu Yin
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Marissa K Oram
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Liangjun Wang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - John Taylor
- Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Jack Hedberg
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Colette B Rogers
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Adam J Harvey
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Debashree Basu
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jenny C Taylor
- Wellcome Centre Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
- Oxford NIHR Biomedical Research Centre, Oxford, OX3 7BN, UK
| | - Alistair T Pagnamenta
- Wellcome Centre Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
- Oxford NIHR Biomedical Research Centre, Oxford, OX3 7BN, UK
| | - Helene Dreau
- Department of Haematology, University of Oxford, Oxford, OX3 7BN, UK
| | - Jude Craft
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Elizabeth Ormondroyd
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Hugh Watkins
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Eric A Hendrickson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Emily M Mace
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Jordan S Orange
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Grant S Stewart
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Edward Blair
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Jeanette Gowen Cook
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA.
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11
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Schmit M, Bielinsky AK. Congenital Diseases of DNA Replication: Clinical Phenotypes and Molecular Mechanisms. Int J Mol Sci 2021; 22:E911. [PMID: 33477564 PMCID: PMC7831139 DOI: 10.3390/ijms22020911] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/19/2022] Open
Abstract
Deoxyribonucleic acid (DNA) replication can be divided into three major steps: initiation, elongation and termination. Each time a human cell divides, these steps must be reiteratively carried out. Disruption of DNA replication can lead to genomic instability, with the accumulation of point mutations or larger chromosomal anomalies such as rearrangements. While cancer is the most common class of disease associated with genomic instability, several congenital diseases with dysfunctional DNA replication give rise to similar DNA alterations. In this review, we discuss all congenital diseases that arise from pathogenic variants in essential replication genes across the spectrum of aberrant replisome assembly, origin activation and DNA synthesis. For each of these conditions, we describe their clinical phenotypes as well as molecular studies aimed at determining the functional mechanisms of disease, including the assessment of genomic stability. By comparing and contrasting these diseases, we hope to illuminate how the disruption of DNA replication at distinct steps affects human health in a surprisingly cell-type-specific manner.
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Affiliation(s)
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA;
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12
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Stroik S, Kurtz K, Lin K, Karachenets S, Myers CL, Bielinsky AK, Hendrickson EA. EXO1 resection at G-quadruplex structures facilitates resolution and replication. Nucleic Acids Res 2020; 48:4960-4975. [PMID: 32232411 PMCID: PMC7229832 DOI: 10.1093/nar/gkaa199] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 02/08/2020] [Accepted: 03/16/2020] [Indexed: 01/25/2023] Open
Abstract
G-quadruplexes represent unique roadblocks to DNA replication, which tends to stall at these secondary structures. Although G-quadruplexes can be found throughout the genome, telomeres, due to their G-richness, are particularly predisposed to forming these structures and thus represent difficult-to-replicate regions. Here, we demonstrate that exonuclease 1 (EXO1) plays a key role in the resolution of, and replication through, telomeric G-quadruplexes. When replication forks encounter G-quadruplexes, EXO1 resects the nascent DNA proximal to these structures to facilitate fork progression and faithful replication. In the absence of EXO1, forks accumulate at stabilized G-quadruplexes and ultimately collapse. These collapsed forks are preferentially repaired via error-prone end joining as depletion of EXO1 diverts repair away from error-free homology-dependent repair. Such aberrant repair leads to increased genomic instability, which is exacerbated at chromosome termini in the form of dysfunction and telomere loss.
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Affiliation(s)
- Susanna Stroik
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel, Hill, NC 27514, USA
| | - Kevin Kurtz
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Kevin Lin
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Sergey Karachenets
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Chad L Myers
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Eric A Hendrickson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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13
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Thakar T, Leung W, Nicolae CM, Clements KE, Shen B, Bielinsky AK, Moldovan GL. Ubiquitinated-PCNA protects replication forks from DNA2-mediated degradation by regulating Okazaki fragment maturation and chromatin assembly. Nat Commun 2020; 11:2147. [PMID: 32358495 PMCID: PMC7195461 DOI: 10.1038/s41467-020-16096-w] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 04/14/2020] [Indexed: 12/11/2022] Open
Abstract
Upon genotoxic stress, PCNA ubiquitination allows for replication of damaged DNA by recruiting lesion-bypass DNA polymerases. However, PCNA is also ubiquitinated during normal S-phase progression. By employing 293T and RPE1 cells deficient in PCNA ubiquitination, generated through CRISPR/Cas9 gene editing, here, we show that this modification promotes cellular proliferation and suppression of genomic instability under normal growth conditions. Loss of PCNA-ubiquitination results in DNA2-dependent but MRE11-independent nucleolytic degradation of nascent DNA at stalled replication forks. This degradation is linked to defective gap-filling in the wake of the replication fork and incomplete Okazaki fragment maturation, which interferes with efficient PCNA unloading by ATAD5 and subsequent nucleosome deposition by CAF-1. Moreover, concomitant loss of PCNA-ubiquitination and the BRCA pathway results in increased nascent DNA degradation and PARP inhibitor sensitivity. In conclusion, we show that by ensuring efficient Okazaki fragment maturation, PCNA-ubiquitination protects fork integrity and promotes the resistance of BRCA-deficient cells to PARP-inhibitors.
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Affiliation(s)
- Tanay Thakar
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Wendy Leung
- Department of Biochemistry, Molecular Biology and Biophysics, College of Biological Sciences, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Claudia M Nicolae
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Kristen E Clements
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Binghui Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, Duarte, CA, 91010, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, College of Biological Sciences, University of Minnesota, Minneapolis, MN, 55455, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
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14
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Paulson CN, John K, Baxley RM, Kurniawan F, Orellana K, Francis R, Sobeck A, Eichman BF, Chazin WJ, Aihara H, Georg GI, Hawkinson JE, Bielinsky AK. The anti-parasitic agent suramin and several of its analogues are inhibitors of the DNA binding protein Mcm10. Open Biol 2019; 9:190117. [PMID: 31409229 PMCID: PMC6731595 DOI: 10.1098/rsob.190117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Minichromosome maintenance protein 10 (Mcm10) is essential for DNA unwinding by the replisome during S phase. It is emerging as a promising anti-cancer target as MCM10 expression correlates with tumour progression and poor clinical outcomes. Here we used a competition-based fluorescence polarization (FP) high-throughput screening (HTS) strategy to identify compounds that inhibit Mcm10 from binding to DNA. Of the five active compounds identified, only the anti-parasitic agent suramin exhibited a dose-dependent decrease in replication products in an in vitro replication assay. Structure–activity relationship evaluation identified several suramin analogues that inhibited ssDNA binding by the human Mcm10 internal domain and full-length Xenopus Mcm10, including analogues that are selective for Mcm10 over human RPA. Binding of suramin analogues to Mcm10 was confirmed by surface plasmon resonance (SPR). SPR and FP affinity determinations were highly correlated, with a similar rank between affinity and potency for killing colon cancer cells. Suramin analogue NF157 had the highest human Mcm10 binding affinity (FP Ki 170 nM, SPR KD 460 nM) and cell activity (IC50 38 µM). Suramin and its analogues are the first identified inhibitors of Mcm10 and probably block DNA binding by mimicking the DNA sugar phosphate backbone due to their extended, polysulfated anionic structures.
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Affiliation(s)
- Carolyn N Paulson
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery & Development, College of Pharmacy, University of Minnesota, Minneapolis, MN 55414, USA
| | - Kristen John
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery & Development, College of Pharmacy, University of Minnesota, Minneapolis, MN 55414, USA
| | - Ryan M Baxley
- Department of Biochemistry, Molecular Biology and Biophysics, College of Biological Sciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Fredy Kurniawan
- Department of Biochemistry, Molecular Biology and Biophysics, College of Biological Sciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kayo Orellana
- Department of Biochemistry, Molecular Biology and Biophysics, College of Biological Sciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Rawle Francis
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery & Development, College of Pharmacy, University of Minnesota, Minneapolis, MN 55414, USA
| | - Alexandra Sobeck
- Department of Biochemistry, Molecular Biology and Biophysics, College of Biological Sciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Brandt F Eichman
- Departments of Biological Sciences and Biochemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Walter J Chazin
- Departments of Biochemistry and Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology and Biophysics, College of Biological Sciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Gunda I Georg
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery & Development, College of Pharmacy, University of Minnesota, Minneapolis, MN 55414, USA
| | - Jon E Hawkinson
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery & Development, College of Pharmacy, University of Minnesota, Minneapolis, MN 55414, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, College of Biological Sciences, University of Minnesota, Minneapolis, MN 55455, USA
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15
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Becker JR, Gallo D, Leung W, Croissant T, Thu YM, Nguyen HD, Starr TK, Brown GW, Bielinsky AK. Flap endonuclease overexpression drives genome instability and DNA damage hypersensitivity in a PCNA-dependent manner. Nucleic Acids Res 2019; 46:5634-5650. [PMID: 29741650 PMCID: PMC6009675 DOI: 10.1093/nar/gky313] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 04/16/2018] [Indexed: 12/31/2022] Open
Abstract
Overexpression of the flap endonuclease FEN1 has been observed in a variety of cancer types and is a marker for poor prognosis. To better understand the cellular consequences of FEN1 overexpression we utilized a model of its Saccharomyces cerevisiae homolog, RAD27. In this system, we discovered that flap endonuclease overexpression impedes replication fork progression and leads to an accumulation of cells in mid-S phase. This was accompanied by increased phosphorylation of the checkpoint kinase Rad53 and histone H2A-S129. RAD27 overexpressing cells were hypersensitive to treatment with DNA damaging agents, and defective in ubiquitinating the replication clamp proliferating cell nuclear antigen (PCNA) at lysine 164. These effects were reversed when the interaction between overexpressed Rad27 and PCNA was ablated, suggesting that the observed phenotypes were linked to problems in DNA replication. RAD27 overexpressing cells also exhibited an unexpected dependence on the SUMO ligases SIZ1 and MMS21 for viability. Importantly, we found that overexpression of FEN1 in human cells also led to phosphorylation of CHK1, CHK2, RPA32 and histone H2AX, all markers of genome instability. Our data indicate that flap endonuclease overexpression is a driver of genome instability in yeast and human cells that impairs DNA replication in a manner dependent on its interaction with PCNA.
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Affiliation(s)
- Jordan R Becker
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - David Gallo
- Department of Biochemistry and Donnelly Centre, University of Toronto, Toronto, ON M5S 3E2, Canada
| | - Wendy Leung
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Taylor Croissant
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yee Mon Thu
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Hai Dang Nguyen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Timothy K Starr
- Department of Obstetrics, Gynecology, and Women's Health, University of Minnesota, Minneapolis, MN 55455, USA
| | - Grant W Brown
- Department of Biochemistry and Donnelly Centre, University of Toronto, Toronto, ON M5S 3E2, Canada
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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16
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Matson JP, Dumitru R, Coryell P, Baxley RM, Chen W, Twaroski K, Webber BR, Tolar J, Bielinsky AK, Purvis JE, Cook JG. Correction: Rapid DNA replication origin licensing protects stem cell pluripotency. eLife 2019; 8:49040. [PMID: 31166167 PMCID: PMC6550866 DOI: 10.7554/elife.49040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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17
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Leung W, Baxley RM, Moldovan GL, Bielinsky AK. Mechanisms of DNA Damage Tolerance: Post-Translational Regulation of PCNA. Genes (Basel) 2018; 10:genes10010010. [PMID: 30586904 PMCID: PMC6356670 DOI: 10.3390/genes10010010] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022] Open
Abstract
DNA damage is a constant source of stress challenging genomic integrity. To ensure faithful duplication of our genomes, mechanisms have evolved to deal with damage encountered during replication. One such mechanism is referred to as DNA damage tolerance (DDT). DDT allows for replication to continue in the presence of a DNA lesion by promoting damage bypass. Two major DDT pathways exist: error-prone translesion synthesis (TLS) and error-free template switching (TS). TLS recruits low-fidelity DNA polymerases to directly replicate across the damaged template, whereas TS uses the nascent sister chromatid as a template for bypass. Both pathways must be tightly controlled to prevent the accumulation of mutations that can occur from the dysregulation of DDT proteins. A key regulator of error-prone versus error-free DDT is the replication clamp, proliferating cell nuclear antigen (PCNA). Post-translational modifications (PTMs) of PCNA, mainly by ubiquitin and SUMO (small ubiquitin-like modifier), play a critical role in DDT. In this review, we will discuss the different types of PTMs of PCNA and how they regulate DDT in response to replication stress. We will also cover the roles of PCNA PTMs in lagging strand synthesis, meiotic recombination, as well as somatic hypermutation and class switch recombination.
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Affiliation(s)
- Wendy Leung
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Ryan M Baxley
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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18
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Kurniawan F, Shi K, Kurahashi K, Bielinsky AK, Aihara H. Crystal Structure of Entamoeba histolytica Cdc45 Suggests a Conformational Switch that May Regulate DNA Replication. iScience 2018; 3:102-109. [PMID: 29901028 PMCID: PMC5994768 DOI: 10.1016/j.isci.2018.04.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2022] Open
Abstract
Cdc45 plays a critical role at the core of the eukaryotic DNA replisome, serving as an essential scaffolding component of the replicative helicase holoenzyme Cdc45-MCM-GINS (CMG) complex. A 1.66-Å-resolution crystal structure of the full-length Cdc45 protein from Entamoeba histolytica shows a protein fold similar to that observed previously for human Cdc45 in its active conformation, featuring the overall disk-like monomer shape and intimate contacts between the N- and C-terminal DHH domains. However, the E. histolytica Cdc45 structure shows several unique features, including a distinct orientation of the C-terminal DHHA1 domain, concomitant disordering of the adjacent protruding α-helical segment implicated in DNA polymerase ε interactions, and a unique conformation of the GINS/Mcm5-binding loop. These structural observations collectively suggest the possibility that Cdc45 can sample multiple conformations corresponding to different functional states. We propose that such conformational switch of Cdc45 may allow regulation of protein-protein interactions important in DNA replication.
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Affiliation(s)
- Fredy Kurniawan
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ke Shi
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kayo Kurahashi
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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Matson JP, Dumitru R, Coryell P, Baxley RM, Chen W, Twaroski K, Webber BR, Tolar J, Bielinsky AK, Purvis JE, Cook JG. Rapid DNA replication origin licensing protects stem cell pluripotency. eLife 2017; 6:30473. [PMID: 29148972 PMCID: PMC5720591 DOI: 10.7554/elife.30473] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 11/16/2017] [Indexed: 11/24/2022] Open
Abstract
Complete and robust human genome duplication requires loading minichromosome maintenance (MCM) helicase complexes at many DNA replication origins, an essential process termed origin licensing. Licensing is restricted to G1 phase of the cell cycle, but G1 length varies widely among cell types. Using quantitative single-cell analyses, we found that pluripotent stem cells with naturally short G1 phases load MCM much faster than their isogenic differentiated counterparts with long G1 phases. During the earliest stages of differentiation toward all lineages, MCM loading slows concurrently with G1 lengthening, revealing developmental control of MCM loading. In contrast, ectopic Cyclin E overproduction uncouples short G1 from fast MCM loading. Rapid licensing in stem cells is caused by accumulation of the MCM loading protein, Cdt1. Prematurely slowing MCM loading in pluripotent cells not only lengthens G1 but also accelerates differentiation. Thus, rapid origin licensing is an intrinsic characteristic of stem cells that contributes to pluripotency maintenance. From red blood cells to nerve cells, animals’ bodies contain many different types of specialized cells. These all begin as stem cells, which have the potential to divide and make more stem cells or to specialize. All dividing cells must first unwind their DNA so that it can be copied. To achieve this, cells load DNA-unwinding enzymes called helicases onto their DNA during the part of the cell cycle known as G1 phase. Cells must load enough helicase enzymes to ensure that their DNA is copied completely and in time. Stem cells divide faster than their specialized descendants, and have a much shorter G1 phase too. Yet these cells still manage to load enough helicases to copy their DNA. Little is known about how the amount, rate and timing of helicase loading varies between cells that divide at different speeds. Now Matson et al. have measured how quickly helicase enzymes are loaded onto DNA in individual human cells, including stem cells and specialized or “differentiated” cells. Stem cells loaded helicases rapidly to make up for the short time they spent in G1 phase, while differentiated cells loaded the enzymes more slowly. Measuring how the loading rate changed when stem cells were triggered to specialize showed that helicase loading slowed as the G1 phase got longer. Matson et al. found that the levels of key proteins required for helicase loading correlated with the rates of loading. Altering the levels of the proteins changed how quickly the enzymes were loaded and how the cells behaved – for example, slowing down the loading of helicases made the stem cells specialize quicker. These findings show that the processes of cell differentiation and DNA replication are closely linked. This study and future ones will help scientists understand what is happening during early animal development, when specialization first takes place, as well as what has gone wrong in cancer cells, which also divide quickly. A better understanding of this process also helps in regenerative medicine – where one of the challenges is to make enough specialized cells to transplant into a patient with tissue damage without those cells becoming cancerous.
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Affiliation(s)
- Jacob Peter Matson
- Department of Biochemistry and Biophysics, The University of North Carolina, Chapel Hill, United States
| | - Raluca Dumitru
- Human Pluripotent Stem Cell Core Facility, The University of North Carolina, Chapel Hill, United States
| | - Philip Coryell
- Department of Genetics, The University of North Carolina, Chapel Hill, United States
| | - Ryan M Baxley
- Department of Biochemistry, Molecular Biology, and Biophysics, The University of Minnesota, Minneapolis, United States
| | - Weili Chen
- Stem Cell Institute, University of Minnesota, Minnesota, United States
| | - Kirk Twaroski
- Stem Cell Institute, University of Minnesota, Minnesota, United States
| | - Beau R Webber
- Stem Cell Institute, University of Minnesota, Minnesota, United States
| | - Jakub Tolar
- Stem Cell Institute, University of Minnesota, Minnesota, United States
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, The University of Minnesota, Minneapolis, United States
| | - Jeremy E Purvis
- Department of Genetics, The University of North Carolina, Chapel Hill, United States.,Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, United States
| | - Jeanette Gowen Cook
- Department of Biochemistry and Biophysics, The University of North Carolina, Chapel Hill, United States.,Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, United States
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Bielinsky AK, Leung W. Not just for coding: a new role for histone tails in replication enzyme activation. FEBS J 2017; 283:4244-4246. [PMID: 27921370 DOI: 10.1111/febs.13958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The processing of Okazaki fragments when they are assembled into nucleosomes has received little attention. In this issue of The FEBS Journal, Seo and colleagues show that binding to histone tails stimulates the enzymatic activity of flap endonuclease 1 (Rad27). Histone tails are structurally similar to the C terminus of Rad27 and can thus mimic its autostimulatory function. This study highlights an active regulatory role for nucleosomes on DNA metabolism.
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Affiliation(s)
- Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Wendy Leung
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
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Abstract
Minichromosome maintenance protein (Mcm) 10 is a part of the eukaryotic replication machinery and highly conserved throughout evolution. As a multivalent DNA scaffold, Mcm10 coordinates the action of proteins that are indispensable for lagging strand synthesis, such as the replication clamp, proliferating cell nuclear antigen (PCNA). The binding between Mcm10 and PCNA serves an essential function during DNA elongation and is mediated by the ubiquitination of Mcm10. Here we map lysine 372 as the primary attachment site for ubiquitin on S. cerevisiae Mcm10. Moreover, we identify five additional lysines that can be ubiquitinated. Mutation of lysine 372 to arginine ablates ubiquitination of overexpressed protein and causes sensitivity to the replication inhibitor hydroxyurea in cells that are S-phase checkpoint compromised. Together, these findings reveal the high selectivity of the ubiquitination machinery that targets Mcm10 and that ubiquitination has a role in suppressing replication stress. S. cerevisiae Mcm10 is ubiquitinated at lysine 372. Alternative ubiquitination sites exist at five specific lysine residues. The mcm10-K372R mutation synergizes with a 9-1-1 checkpoint deficiency.
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Affiliation(s)
- Tianji Zhang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, 55455, United States of America
| | - Brandy L Fultz
- Department of Natural Sciences, College of Science and Health Professions, Northeastern State University, 3100 East New Orleans Street, Broken Arrow, OK 74014
| | - Sapna Das-Bradoo
- Department of Natural Sciences, College of Science and Health Professions, Northeastern State University, 3100 East New Orleans Street, Broken Arrow, OK 74014
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, 55455, United States of America
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Affiliation(s)
- Anja-Katrin Bielinsky
- a Department of Biochemistry , Molecular Biology, and Biophysics, University of Minnesota , Minneapolis , MN , USA
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Bielinsky AK. Penetrating enemy territory: Soluble PCNA-peptides stress out MYCN-overexpressing neuroblastomas. EBioMedicine 2016; 2:1844-5. [PMID: 26844252 PMCID: PMC4703722 DOI: 10.1016/j.ebiom.2015.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States
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Becker JR, Pons C, Nguyen HD, Costanzo M, Boone C, Myers CL, Bielinsky AK. Genetic Interactions Implicating Postreplicative Repair in Okazaki Fragment Processing. PLoS Genet 2015; 11:e1005659. [PMID: 26545110 PMCID: PMC4636136 DOI: 10.1371/journal.pgen.1005659] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/19/2015] [Indexed: 01/28/2023] Open
Abstract
Ubiquitination of the replication clamp proliferating cell nuclear antigen (PCNA) at the conserved residue lysine (K)164 triggers postreplicative repair (PRR) to fill single-stranded gaps that result from stalled DNA polymerases. However, it has remained elusive as to whether cells engage PRR in response to replication defects that do not directly impair DNA synthesis. To experimentally address this question, we performed synthetic genetic array (SGA) analysis with a ubiquitination-deficient K164 to arginine (K164R) mutant of PCNA against a library of S. cerevisiae temperature-sensitive alleles. The SGA signature of the K164R allele showed a striking correlation with profiles of mutants deficient in various aspects of lagging strand replication, including rad27Δ and elg1Δ. Rad27 is the primary flap endonuclease that processes 5' flaps generated during lagging strand replication, whereas Elg1 has been implicated in unloading PCNA from chromatin. We observed chronic ubiquitination of PCNA at K164 in both rad27Δ and elg1Δ mutants. Notably, only rad27Δ cells exhibited a decline in cell viability upon elimination of PRR pathways, whereas elg1Δ mutants were not affected. We further provide evidence that K164 ubiquitination suppresses replication stress resulting from defective flap processing during Okazaki fragment maturation. Accordingly, ablation of PCNA ubiquitination increased S phase checkpoint activation, indicated by hyperphosphorylation of the Rad53 kinase. Furthermore, we demonstrate that alternative flap processing by overexpression of catalytically active exonuclease 1 eliminates PCNA ubiquitination. This suggests a model in which unprocessed flaps may directly participate in PRR signaling. Our findings demonstrate that PCNA ubiquitination at K164 in response to replication stress is not limited to DNA synthesis defects but extends to DNA processing during lagging strand replication.
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Affiliation(s)
- Jordan R. Becker
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Carles Pons
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Hai Dang Nguyen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Michael Costanzo
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Charles Boone
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Chad L. Myers
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
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Avdulov S, Herrera J, Smith K, Peterson M, Gomez-Garcia JR, Beadnell TC, Schwertfeger KL, Benyumov AO, Manivel JC, Li S, Bielinsky AK, Yee D, Bitterman PB, Polunovsky VA. eIF4E threshold levels differ in governing normal and neoplastic expansion of mammary stem and luminal progenitor cells. Cancer Res 2014; 75:687-97. [PMID: 25524901 DOI: 10.1158/0008-5472.can-14-2571] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Translation initiation factor eIF4E mediates normal cell proliferation, yet induces tumorigenesis when overexpressed. The mechanisms by which eIF4E directs such distinct biologic outputs remain unknown. We found that mouse mammary morphogenesis during pregnancy and lactation is accompanied by increased cap-binding capability of eIF4E and activation of the eIF4E-dependent translational apparatus, but only subtle oscillations in eIF4E abundance. Using a transgenic mouse model engineered so that lactogenic hormones stimulate a sustained increase in eIF4E abundance in stem/progenitor cells of lactogenic mammary epithelium during successive pregnancy/lactation cycles, eIF4E overexpression increased self-renewal, triggered DNA replication stress, and induced formation of premalignant and malignant lesions. Using complementary in vivo and ex vivo approaches, we found that increasing eIF4E levels rescued cells harboring oncogenic c-Myc or H-RasV12 from DNA replication stress and oncogene-induced replication catastrophe. Our findings indicate that distinct threshold levels of eIF4E govern its biologic output in lactating mammary glands and that eIF4E overexpression in the context of stem/progenitor cell population expansion can initiate malignant transformation by enabling cells to evade DNA damage checkpoints activated by oncogenic stimuli. Maintaining eIF4E levels below its proneoplastic threshold is an important anticancer defense in normal cells, with important implications for understanding pregnancy-associated breast cancer.
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Affiliation(s)
- Svetlana Avdulov
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Jeremy Herrera
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Karen Smith
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Mark Peterson
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | | | - Thomas C Beadnell
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota
| | - Kathryn L Schwertfeger
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota. Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Alexey O Benyumov
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - J Carlos Manivel
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota
| | - Shunan Li
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Anja-Katrin Bielinsky
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota. Departament of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Douglas Yee
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota. Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Peter B Bitterman
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota. Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota.
| | - Vitaly A Polunovsky
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota. Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota.
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Alver RC, Zhang T, Josephrajan A, Fultz BL, Hendrix CJ, Das-Bradoo S, Bielinsky AK. The N-terminus of Mcm10 is important for interaction with the 9-1-1 clamp and in resistance to DNA damage. Nucleic Acids Res 2014; 42:8389-404. [PMID: 24972833 PMCID: PMC4117747 DOI: 10.1093/nar/gku479] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Accurate replication of the genome requires the evolutionarily conserved minichromosome maintenance protein, Mcm10. Although the details of the precise role of Mcm10 in DNA replication are still debated, it interacts with the Mcm2-7 core helicase, the lagging strand polymerase, DNA polymerase-α and the replication clamp, proliferating cell nuclear antigen. Loss of these interactions caused by the depletion of Mcm10 leads to chromosome breakage and cell cycle checkpoint activation. However, whether Mcm10 has an active role in DNA damage prevention is unknown. Here, we present data that establish a novel role of the N-terminus of Mcm10 in resisting DNA damage. We show that Mcm10 interacts with the Mec3 subunit of the 9-1-1 clamp in response to replication stress evoked by UV irradiation or nucleotide shortage. We map the interaction domain with Mec3 within the N-terminal region of Mcm10 and demonstrate that its truncation causes UV light sensitivity. This sensitivity is not further enhanced by a deletion of MEC3, arguing that MCM10 and MEC3 operate in the same pathway. Since Rad53 phosphorylation in response to UV light appears to be normal in N-terminally truncated mcm10 mutants, we propose that Mcm10 may have a role in replication fork restart or DNA repair.
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Affiliation(s)
- Robert C Alver
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Tianji Zhang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ajeetha Josephrajan
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Brandy L Fultz
- Department of Natural Sciences, Northeastern State University, 3100 East New Orleans Street, Broken Arrow, OK 74012, USA
| | - Chance J Hendrix
- Department of Natural Sciences, Northeastern State University, 3100 East New Orleans Street, Broken Arrow, OK 74012, USA
| | - Sapna Das-Bradoo
- Department of Natural Sciences, Northeastern State University, 3100 East New Orleans Street, Broken Arrow, OK 74012, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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Becker JR, Nguyen HD, Wang X, Bielinsky AK. Mcm10 deficiency causes defective-replisome-induced mutagenesis and a dependency on error-free postreplicative repair. Cell Cycle 2014; 13:1737-48. [PMID: 24674891 DOI: 10.4161/cc.28652] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Mcm10 is a multifunctional replication factor with reported roles in origin activation, polymerase loading, and replication fork progression. The literature supporting these variable roles is controversial, and it has been debated whether Mcm10 has an active role in elongation. Here, we provide evidence that the mcm10-1 allele confers alterations in DNA synthesis that lead to defective-replisome-induced mutagenesis (DRIM). Specifically, we observed that mcm10-1 cells exhibited elevated levels of PCNA ubiquitination and activation of the translesion polymerase, pol-ζ. Whereas translesion synthesis had no measurable impact on viability, mcm10-1 mutants also engaged in error-free postreplicative repair (PRR), and this pathway promoted survival at semi-permissive conditions. Replication gaps in mcm10-1 were likely caused by elongation defects, as dbf4-1 mutants, which are compromised for origin activation did not display any hallmarks of replication stress. Furthermore, we demonstrate that deficiencies in priming, induced by a pol1-1 mutation, also resulted in DRIM, but not in error-free PRR. Similar to mcm10-1 mutants, DRIM did not rescue the replication defect in pol1-1 cells. Thus, it appears that DRIM is not proficient to fill replication gaps in pol1-1 and mcm10-1 mutants. Moreover, the ability to correctly prime nascent DNA may be a crucial prerequisite to initiate error-free PRR.
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Affiliation(s)
- Jordan R Becker
- Department of Biochemistry, Molecular Biology, and Biophysics; University of Minnesota; Minneapolis, MN USA
| | - Hai Dang Nguyen
- Department of Biochemistry, Molecular Biology, and Biophysics; University of Minnesota; Minneapolis, MN USA
| | - Xiaohan Wang
- Department of Biochemistry, Molecular Biology, and Biophysics; University of Minnesota; Minneapolis, MN USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics; University of Minnesota; Minneapolis, MN USA
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Abstract
Minichromsome maintenance protein 10 (Mcm10) is an essential replication factor that is required for the activation of the Cdc45:Mcm2-7:GINS helicase. Mcm10's ability to bind both ds and ssDNA appears vital for this function. In addition, Mcm10 interacts with multiple players at the replication fork, including DNA polymerase-α and proliferating cell nuclear antigen with which it cooperates during DNA elongation. Mcm10 lacks enzymatic function, but instead provides the replication apparatus with an oligomeric scaffold that likely acts in the coordination of DNA unwinding and DNA synthesis. Not surprisingly, loss of Mcm10 engages checkpoint, DNA repair and SUMO-dependent rescue pathways that collectively counteract replication stress and chromosome breakage. Here, we review Mcm10's structure and function and explain how it contributes to the maintenance of genome integrity.
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Affiliation(s)
- Yee Mon Thu
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States.
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Ragland RL, Patel S, Rivard RS, Smith K, Peters AA, Bielinsky AK, Brown EJ. RNF4 and PLK1 are required for replication fork collapse in ATR-deficient cells. Genes Dev 2013; 27:2259-73. [PMID: 24142876 PMCID: PMC3814646 DOI: 10.1101/gad.223180.113] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 09/12/2013] [Indexed: 11/25/2022]
Abstract
The ATR-CHK1 axis stabilizes stalled replication forks and prevents their collapse into DNA double-strand breaks (DSBs). Here, we show that fork collapse in Atr-deleted cells is mediated through the combined effects the sumo targeted E3-ubiquitin ligase RNF4 and activation of the AURKA-PLK1 pathway. As indicated previously, Atr-deleted cells exhibited a decreased ability to restart DNA replication following fork stalling in comparison with control cells. However, suppression of RNF4, AURKA, or PLK1 returned the reinitiation of replication in Atr-deleted cells to near wild-type levels. In RNF4-depleted cells, this rescue directly correlated with the persistence of sumoylation of chromatin-bound factors. Notably, RNF4 repression substantially suppressed the accumulation of DSBs in ATR-deficient cells, and this decrease in breaks was enhanced by concomitant inhibition of PLK1. DSBs resulting from ATR inhibition were also observed to be dependent on the endonuclease scaffold protein SLX4, suggesting that RNF4 and PLK1 either help activate the SLX4 complex or make DNA replication fork structures accessible for subsequent SLX4-dependent cleavage. Thus, replication fork collapse following ATR inhibition is a multistep process that disrupts replisome function and permits cleavage of the replication fork.
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Affiliation(s)
- Ryan L. Ragland
- Abramson Family Cancer Research Institute, Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Sima Patel
- Abramson Family Cancer Research Institute, Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Rebecca S. Rivard
- Abramson Family Cancer Research Institute, Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Kevin Smith
- Abramson Family Cancer Research Institute, Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Ashley A. Peters
- Abramson Family Cancer Research Institute, Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Eric J. Brown
- Abramson Family Cancer Research Institute, Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Nguyen HD, Becker J, Thu YM, Costanzo M, Koch EN, Smith S, Myung K, Myers CL, Boone C, Bielinsky AK. Unligated Okazaki Fragments Induce PCNA Ubiquitination and a Requirement for Rad59-Dependent Replication Fork Progression. PLoS One 2013; 8:e66379. [PMID: 23824283 PMCID: PMC3688925 DOI: 10.1371/journal.pone.0066379] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Accepted: 05/07/2013] [Indexed: 11/28/2022] Open
Abstract
Deficiency in DNA ligase I, encoded by CDC9 in budding yeast, leads to the accumulation of unligated Okazaki fragments and triggers PCNA ubiquitination at a non-canonical lysine residue. This signal is crucial to activate the S phase checkpoint, which promotes cell cycle delay. We report here that a pol30-K107 mutation alleviated cell cycle delay in cdc9 mutants, consistent with the idea that the modification of PCNA at K107 affects the rate of DNA synthesis at replication forks. To determine whether PCNA ubiquitination occurred in response to nicks or was triggered by the lack of PCNA-DNA ligase interaction, we complemented cdc9 cells with either wild-type DNA ligase I or a mutant form, which fails to interact with PCNA. Both enzymes reversed PCNA ubiquitination, arguing that the modification is likely an integral part of a novel nick-sensory mechanism and not due to non-specific secondary mutations that could have occurred spontaneously in cdc9 mutants. To further understand how cells cope with the accumulation of nicks during DNA replication, we utilized cdc9-1 in a genome-wide synthetic lethality screen, which identified RAD59 as a strong negative interactor. In comparison to cdc9 single mutants, cdc9 rad59Δ double mutants did not alter PCNA ubiquitination but enhanced phosphorylation of the mediator of the replication checkpoint, Mrc1. Since Mrc1 resides at the replication fork and is phosphorylated in response to fork stalling, these results indicate that Rad59 alleviates nick-induced replication fork slowdown. Thus, we propose that Rad59 promotes fork progression when Okazaki fragment processing is compromised and counteracts PCNA-K107 mediated cell cycle arrest.
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Affiliation(s)
- Hai Dang Nguyen
- University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics, Minneapolis, Minnesota, United States of America
| | - Jordan Becker
- University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics, Minneapolis, Minnesota, United States of America
| | - Yee Mon Thu
- University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics, Minneapolis, Minnesota, United States of America
| | - Michael Costanzo
- Banting and Best Department of Medical Research, The Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth N. Koch
- University of Minnesota, Department of Computer Science and Engineering, Minneapolis, Minnesota, United States of America
| | - Stephanie Smith
- Genome Instability Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kyungjae Myung
- Genome Instability Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Chad L. Myers
- University of Minnesota, Department of Computer Science and Engineering, Minneapolis, Minnesota, United States of America
| | - Charles Boone
- Banting and Best Department of Medical Research, The Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Anja-Katrin Bielinsky
- University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics, Minneapolis, Minnesota, United States of America
- * E-mail:
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Thu YM, Bielinsky AK. Enigmatic roles of Mcm10 in DNA replication. Trends Biochem Sci 2013; 38:184-94. [PMID: 23332289 DOI: 10.1016/j.tibs.2012.12.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 11/30/2012] [Accepted: 12/07/2012] [Indexed: 12/31/2022]
Abstract
Minichromosome maintenance protein 10 (Mcm10) is required for DNA replication in all eukaryotes. Although the exact contribution of Mcm10 to genome replication remains heavily debated, early reports suggested that it promotes DNA unwinding and origin firing. These ideas have been solidified by recent studies that propose a role for Mcm10 in helicase activation. Whereas the molecular underpinnings of this activation step have yet to be revealed, structural data on Mcm10 provide further insight into a possible mechanism of action. The essential role in DNA replication initiation is not mutually exclusive with additional functions that Mcm10 may have as part of the elongation machinery. Here, we review the recent findings regarding the role of Mcm10 in DNA replication and discuss existing controversies.
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Affiliation(s)
- Yee Mon Thu
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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33
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Abstract
In this issue, a study by Groehler and Lannigan (2010. J. Cell Biol. doi:10.1083/jcb.201002124) sheds light on the regulation of proliferating cell nuclear antigen (PCNA) turnover and how it is counteracted by the small chromatin-bound kinase ERK8 (extracellular signal-regulated kinase 8). Importantly, inactivation of ERK8 results in genome instability and is associated with cell transformation.
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Affiliation(s)
- Hai Dang Nguyen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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34
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Abstract
Okazaki fragment processing is an integral part of DNA replication. For a long time, we assumed that the maturation of these small RNA-primed DNA fragments did not necessarily have to occur during S phase, but could be postponed to late in S phase after the bulk of DNA synthesis had been completed. This view was primarily based on the arrest phenotype of temperature-sensitive DNA ligase I mutants in yeast, which accumulated with an almost fully duplicated set of chromosomes. However, many temperature-sensitive alleles can be leaky and the re-evaluation of DNA ligase I-deficient cells has offered new and unexpected insights into how cells keep track of lagging strand synthesis. It turns out that if Okazaki fragment joining goes awry, cells have their own alarm system in the form of ubiquitin that is conjugated to the replication clamp PCNA. Although this modification results in mono- and poly-ubiquitination of PCNA, it is genetically distinct from the known post-replicative repair mark at lysine 164. In this Extra View, we discuss the possibility that eukaryotic cells utilize different enzymatic pathways and ubiquitin attachment sites on PCNA to alert the replication machinery to the accumulation of single-stranded gaps or nicks behind the fork.
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Affiliation(s)
- Sapna Das-Bradoo
- University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics, Minneapolis, MN, USA
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35
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Abstract
In this issue of Molecular Cell, Fachinetti et al. provide the first comprehensive map of replication termination sites (TERs) in Saccharomyces cerevisiae (Fachinetti et al., 2010). Strikingly, the majority of TERs are occupied by topoisomerase 2, which shields these regions against genomic instability.
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Affiliation(s)
- Robert C Alver
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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Haworth J, Alver RC, Anderson M, Bielinsky AK. Ubc4 and Not4 regulate steady-state levels of DNA polymerase-α to promote efficient and accurate DNA replication. Mol Biol Cell 2010; 21:3205-19. [PMID: 20660159 PMCID: PMC2938386 DOI: 10.1091/mbc.e09-06-0452] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
DNA polymerase-alpha (pol-alpha) is essential for eukaryotic replication but lacks proofreading activity. Its turnover is regulated by the E2 Ubc4 and the E3 Not4, which are known transcriptional regulators. This pathway likely prevents accumulation of the potential mutator pol-alpha to promote genome stability. The accurate duplication of chromosomal DNA is required to maintain genomic integrity. However, from an evolutionary point of view, a low mutation rate during DNA replication is desirable. One way to strike the right balance between accuracy and limited mutagenesis is to use a DNA polymerase that lacks proofreading activity but contributes to DNA replication in a very restricted manner. DNA polymerase-α fits this purpose exactly, but little is known about its regulation at the replication fork. Minichromosome maintenance protein (Mcm) 10 regulates the stability of the catalytic subunit of pol-α in budding yeast and human cells. Cdc17, the catalytic subunit of pol-α in yeast, is rapidly degraded after depletion of Mcm10. Here we show that Ubc4 and Not4 are required for Cdc17 destabilization. Disruption of Cdc17 turnover resulted in sensitivity to hydroxyurea, suggesting that this pathway is important for DNA replication. Furthermore, overexpression of Cdc17 in ubc4 and not4 mutants caused slow growth and synthetic dosage lethality, respectively. Our data suggest that Cdc17 levels are very tightly regulated through the opposing forces of Ubc4 and Not4 (destabilization) and Mcm10 (stabilization). We conclude that regular turnover of Cdc17 via Ubc4 and Not4 is required for proper cell proliferation.
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Affiliation(s)
- Justin Haworth
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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37
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Abstract
Duplication of eukaryotic chromosomes begins from multiple sites called origins of replication, with DNA synthesis proceeding bidirectionally away from the origin. There is little detailed information available pertaining to whether replication initiates at specific sites or anywhere within a given origin. The development of replication initiation point (RIP) mapping has made it possible to map start sites for DNA synthesis at the nucleotide level. The key step in RIP mapping is the purification of nascent DNA, which is initiated by small RNA primers. For the removal of broken DNA fragments, we utilize lambda-exonuclease, which digests DNA, but leaves nascent strands intact as long as they have the RNA primer still attached. RIP mapping is a sensitive technique and has been successfully applied to single copy loci in both budding and fission yeast, archaebacteria, and human cells. Studies in yeast have shown that the binding site for the initiator, the origin recognition complex (ORC), lies immediately adjacent to the replication start point, which suggests that ORC directs the initiation machinery to a distinct site. Here, we present a detailed step-by-step protocol for RIP mapping of replication origins in budding yeast.
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Affiliation(s)
- Sapna Das-Bradoo
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
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38
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39
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Warren EM, Vaithiyalingam S, Haworth J, Greer B, Bielinsky AK, Chazin WJ, Eichman BF. Structural basis for DNA binding by replication initiator Mcm10. Structure 2009; 16:1892-901. [PMID: 19081065 DOI: 10.1016/j.str.2008.10.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 10/03/2008] [Accepted: 10/08/2008] [Indexed: 10/21/2022]
Abstract
Mcm10 is an essential eukaryotic DNA replication protein required for assembly and progression of the replication fork. The highly conserved internal domain (Mcm10-ID) has been shown to physically interact with single-stranded (ss) DNA, DNA polymerase alpha, and proliferating cell nuclear antigen (PCNA). The crystal structure of Xenopus laevis Mcm10-ID presented here reveals a DNA binding architecture composed of an oligonucleotide/oligosaccharide-fold followed in tandem by a variant and highly basic zinc finger. NMR chemical shift perturbation and mutational studies of DNA binding activity in vitro reveal how Mcm10 uses this unique surface to engage ssDNA. Corresponding mutations in Saccharomyces cerevisiae result in increased sensitivity to replication stress, demonstrating the functional importance of DNA binding by this region of Mcm10 to replication. In addition, mapping Mcm10 mutations known to disrupt PCNA, polymerase alpha, and DNA interactions onto the crystal structure provides insight into how Mcm10 might coordinate protein and DNA binding within the replisome.
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Affiliation(s)
- Eric M Warren
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
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40
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Raveendranathan M, Bielinsky AK. Analyzing origin activation patterns by copy number change experiments. Methods Mol Biol 2009; 521:279-294. [PMID: 19563112 DOI: 10.1007/978-1-60327-815-7_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Advances in microarray technology have enabled the analysis of replication dynamics on a genome-wide scale, providing deeper insight to the factors that regulate DNA replication. Studies using high-density microarrays have led to the genome-wide identification of replication origins in the budding yeast, Saccharomyces cerevisiae, and enabled the analysis of the global temporal pattern of origin activation under various conditions. We have developed a replication origin array that contains the approximately 430 potential origins in the yeast genome. By detecting the copy number change that occurs as cells progress from G1 to S phase on these arrays, we have produced origin activation patterns in wild-type cells similar to those obtained from previous studies that used whole-genome arrays. We have also applied this method to study S phase checkpoint mutants, providing insight into the genome-wide regulation of replication origin activation by S phase checkpoint kinases in the presence of replication stress. The main procedures of this technique involve arresting yeast cells in G1 and S phase, isolating and labeling genomic DNA with fluorescent dyes, and cohybridizing the DNA samples to replication origin arrays to yield copy number change data.
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41
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Abstract
In Saccharomyces cerevisiae, minichromosome maintenance protein (Mcm) 10 interacts with DNA polymerase (pol)-alpha and functions as a nuclear chaperone for the catalytic subunit, which is rapidly degraded in the absence of Mcm10. We report here that the interaction between Mcm10 and pol-alpha is conserved in human cells. We used a small interfering RNA-based approach to deplete Mcm10 in HeLa cells, and we observed that the catalytic subunit of pol-alpha, p180, was degraded with similar kinetics as Mcm10, whereas the regulatory pol-alpha subunit, p68, remained unaffected. Simultaneous loss of Mcm10 and p180 inhibited S phase entry and led to an accumulation of already replicating cells in late S/G2 as a result of DNA damage, which triggered apoptosis in a subpopulation of cells. These phenotypes differed considerably from analogous studies in Drosophila embryo cells that did not exhibit a similar arrest. To further dissect the roles of Mcm10 and p180 in human cells, we depleted p180 alone and observed a significant delay in S phase entry and fork progression but little effect on cell viability. These results argue that cells can tolerate low levels of p180 as long as Mcm10 is present to "recycle" it. Thus, human Mcm10 regulates both replication initiation and elongation and maintains genome integrity.
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Affiliation(s)
- Sharbani Chattopadhyay
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
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43
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Abstract
In the quest to define autonomously replicating sequences (ARSs) in eukaryotic cells, an ARS consensus sequence (ACS) has emerged for budding yeast. This ACS is recognized by the replication initiator, the origin recognition complex (ORC). However, not every match to the ACS constitutes a replication origin. Here, we investigated the requirements for ORC binding to origins that carry multiple, redundant ACSs, such as ARS603. Previous studies raised the possibility that these ACSs function as individual ORC binding sites. Detailed mutational analysis of the two ACSs in ARS603 revealed that they function in concert and give rise to an initiation pattern compatible with a single bipartite ORC binding site. Consistent with this notion, deletion of one base pair between the ACS matches abolished ORC binding at ARS603. Importantly, loss of ORC binding in vitro correlated with the loss of ARS activity in vivo. Our results argue that replication origins in yeast are in general comprised of bipartite ORC binding sites that cannot function in random alignment but must conform to a configuration that permits ORC binding. These requirements help to explain why only a limited number of ACS matches in the yeast genome qualify as ORC binding sites.
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Affiliation(s)
| | - Anja-Katrin Bielinsky
- To whom correspondence should be addressed. Tel: +1 612 624 2469; Fax: +1 612 625 2163;
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44
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Abstract
The minichromosome maintenance protein 10 (Mcm10) is an evolutionarily conserved factor that is essential for replication initiation and elongation. Mcm10 is part of the eukaryotic replication fork and interacts with a variety of proteins, including the Mcm2-7 helicase and DNA polymerase alpha/primase complexes. A motif search revealed a match to the proliferating cell nuclear antigen (PCNA)-interacting protein (PIP) box in Mcm10. Here, we demonstrate a direct interaction between Mcm10 and PCNA that is alleviated by mutations in conserved residues of the PIP box. Interestingly, only the diubiquitinated form of Mcm10 binds to PCNA. Diubiquitination of Mcm10 is cell cycle regulated; it first appears in late G(1) and persists throughout S phase. During this time, diubiquitinated Mcm10 is associated with chromatin, suggesting a direct role in DNA replication. Surprisingly, a Y245A substitution in the PIP box of Mcm10 that inhibits the interaction with PCNA abolishes cell proliferation. This severe-growth phenotype, which has not been observed for analogous mutations in other PCNA-interacting proteins, is rescued by a compensatory mutation in PCNA that restores interaction with Mcm10-Y245A. Taken together, our results suggest that diubiquitinated Mcm10 interacts with PCNA to facilitate an essential step in DNA elongation.
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Affiliation(s)
- Sapna Das-Bradoo
- University of Minnesota, Biochemistry, Molecular Biology and Biophysics, 321 Church Street SE, 6-155 Jackson Hall, Minneapolis, MN 55455, USA
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45
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Raveendranathan M, Chattopadhyay S, Bolon YT, Haworth J, Clarke DJ, Bielinsky AK. Genome-wide replication profiles of S-phase checkpoint mutants reveal fragile sites in yeast. EMBO J 2006; 25:3627-39. [PMID: 16888628 PMCID: PMC1538557 DOI: 10.1038/sj.emboj.7601251] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Accepted: 06/30/2006] [Indexed: 12/14/2022] Open
Abstract
The S-phase checkpoint kinases Mec1 and Rad53 in the budding yeast, Saccharomyces cerevisiae, are activated in response to replication stress that induces replication fork arrest. In the absence of a functional S-phase checkpoint, stalled replication forks collapse and give rise to chromosome breakage. In an attempt to better understand replication dynamics in S-phase checkpoint mutants, we developed a replication origin array for budding yeast that contains 424 of 432 previously identified potential origin regions. As expected, mec1-1 and rad53-1 mutants failed to inhibit late origin activation. Surprisingly however, 17 early-firing regions were not replicated efficiently in these mutants. This was not due to a lack of initiation, but rather to problems during elongation, as replication forks arrested in close proximity to these origins, resulting in the accumulation of small replication intermediates and eventual replication fork collapse. Importantly, these regions were not only prone to chromosome breakage in the presence of exogenous stress but also in its absence, similar to fragile sites in the human genome.
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Affiliation(s)
| | - Sharbani Chattopadhyay
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Yung-Tsi Bolon
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Justin Haworth
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Duncan J Clarke
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA. Tel.: +1 612 624 2469; Fax: +1 612 625 2163; E-mail:
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46
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Ricke RM, Bielinsky AK. A conserved Hsp10-like domain in Mcm10 is required to stabilize the catalytic subunit of DNA polymerase-alpha in budding yeast. J Biol Chem 2006; 281:18414-25. [PMID: 16675460 DOI: 10.1074/jbc.m513551200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mcm10 is a conserved eukaryotic DNA replication factor that is required for S phase progression. Recently, Mcm10 has been shown to interact physically with the DNA polymerase-alpha (pol-alpha).primase complex. We show now that Mcm10 is in a complex with pol-alpha throughout the cell cycle. In temperature-sensitive mcm10-1 mutants, depletion of Mcm10 results in degradation of the catalytic subunit of pol-alpha, Cdc17/Pol1, regardless of whether cells are in G(1), S, or G(2) phase. Importantly, Cdc17 protein levels can be restored upon overexpression of exogenous Mcm10 in mcm10-1 mutants that are grown at the nonpermissive temperature. Moreover, overexpressed Cdc17 that is normally subject to rapid degradation is stabilized by Mcm10 co-overexpression but not by co-overexpression of the B-subunit of pol-alpha, Pol12. These results are consistent with Mcm10 having a role as a nuclear chaperone for Cdc17. Mutational analysis indicates that a conserved heat-shock protein 10 (Hsp10)-like domain in Mcm10 is required to prevent the degradation of Cdc17. Substitution of a single residue in the Hsp10-like domain of endogenous Mcm10 results in a dramatic reduction of steady-state Cdc17 levels. The high degree of evolutionary conservation of this domain implies that stabilizing Cdc17 may be a conserved function of Mcm10.
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Affiliation(s)
- Robin M Ricke
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
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47
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Bielinsky AK, Raveendranathan M. Encircled: large-scale purification of replication origins from Mammalian chromosomes. Mol Cell 2006; 21:735-6. [PMID: 16543143 DOI: 10.1016/j.molcel.2006.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A novel cloning strategy for sequences comprising mammalian replication origins, described by Mesner et al. (2006) in a recent issue of Molecular Cell, utilizes an origin trapping assay in which replication bubbles are selectively retained in agarose due to their circular nature.
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Affiliation(s)
- Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, 55455, USA
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48
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Ricke R, Bielinsky AK. Easy detection of chromatin binding proteins by the Histone Association Assay. Biol Proced Online 2005; 7:60-9. [PMID: 16136225 PMCID: PMC1190380 DOI: 10.1251/bpo106] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Revised: 04/08/2005] [Accepted: 04/14/2005] [Indexed: 01/01/2023] Open
Abstract
The Histone Association Assay provides an easy approach for detecting proteins that bind chromatin in vivo. This technique is based on a chromatin immunoprecipitation protocol using histone H3-specific antibodies to precipitate bulk chromatin from crosslinked whole cell extracts. Proteins that co-precipitate with chromatin are subsequently detected by conventional SDS-PAGE and Western blot analysis. Unlike techniques that separate chromatin and non-chromatin interacting proteins by centrifugation, this method can be used to delineate whether a protein is chromatin associated regardless of its innate solubility. Moreover, the relative amount of protein bound to DNA can be ascertained under quantitative conditions. Therefore, this technique may be utilized for analyzing the chromatin association of proteins involved in diverse cellular processes.
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Affiliation(s)
- Robin Ricke
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota. Minneapolis, MN 55455. USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota. Minneapolis, MN 55455. USA
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Ricke RM, Bielinsky AK. Mcm10 regulates the stability and chromatin association of DNA polymerase-alpha. Mol Cell 2004; 16:173-85. [PMID: 15494305 DOI: 10.1016/j.molcel.2004.09.017] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Revised: 08/02/2004] [Accepted: 08/17/2004] [Indexed: 10/26/2022]
Abstract
Mcm10 is a conserved eukaryotic DNA replication factor whose function has remained elusive. We report here that Mcm10 binding to replication origins in budding yeast is cell cycle regulated and dependent on the putative helicase, Mcm2-7. Mcm10 is also an essential component of the replication fork. A fraction of Mcm10 binds to DNA, as shown by histone association assays that allow for the study of chromatin binding in vivo. However, Mcm10 is also required to maintain steady-state levels of DNA polymerase-alpha (polalpha). In temperature-sensitive mcm10-td mutants, depletion of Mcm10 during S phase results in degradation of the catalytic subunit of polalpha, without affecting other fork components such as Cdc45. We propose that Mcm10 stabilizes polalpha and recruits the complex to replication origins. During elongation, Mcm10 is required for the presence of polalpha at replication forks and may coordinate DNA synthesis with DNA unwinding by the Mcm2-7 complex.
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Affiliation(s)
- Robin M Ricke
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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50
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Bielinsky AK. Replication origins: why do we need so many? Cell Cycle 2003; 2:307-9. [PMID: 12851480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] Open
Abstract
During the G1 phase of the cell cycle, replication origins are prepared to fire, a process that is referred to as origin licensing. It was often pondered what a cell's fate would be if not all of its replication origins were licensed and subsequently activated during S phase. One obvious prediction was that S phase would simply be prolonged. As it turns out, however, the consequences are much more complex. A short G1 phase enforced by premature entry into S phase, or other events that negatively affect origin licensing, will ultimately compromise the cell's ability to complete DNA replication before entering mitosis. As a result, the cell becomes genomically unstable when it attempts to repair unreplicated DNA during anaphase. Thus, the density of active replication origins in the chromosomes of eukaryotic cells determines S phase dynamics and chromosome stability during mitosis.
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Affiliation(s)
- Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Molecular and Cellular Biology Building, Room 6-106, 420 Washington Ave SE, Minneapolis, Minnesota 55455, USA.
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