1
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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] [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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2
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Campos LV, Van Ravenstein SX, Vontalge EJ, Greer BH, Heintzman DR, Kavlashvili T, McDonald WH, Rose KL, Eichman BF, Dewar JM. RTEL1 and MCM10 overcome topological stress during vertebrate replication termination. Cell Rep 2023; 42:112109. [PMID: 36807139 PMCID: PMC10432576 DOI: 10.1016/j.celrep.2023.112109] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 11/30/2022] [Accepted: 01/30/2023] [Indexed: 02/19/2023] Open
Abstract
Topological stress can cause converging replication forks to stall during termination of vertebrate DNA synthesis. However, replication forks ultimately overcome fork stalling, suggesting that alternative mechanisms of termination exist. Using proteomics in Xenopus egg extracts, we show that the helicase RTEL1 and the replisome protein MCM10 are highly enriched on chromatin during fork convergence and are crucially important for fork convergence under conditions of topological stress. RTEL1 and MCM10 cooperate to promote fork convergence and do not impact topoisomerase activity but do promote fork progression through a replication barrier. Thus, RTEL1 and MCM10 play a general role in promoting progression of stalled forks, including when forks stall during termination. Our data reveal an alternate mechanism of termination involving RTEL1 and MCM10 that can be used to complete DNA synthesis under conditions of topological stress.
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Affiliation(s)
- Lillian V Campos
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | | | - Emma J Vontalge
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Briana H Greer
- Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Darren R Heintzman
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Tamar Kavlashvili
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - W Hayes McDonald
- Department of Biochemistry and Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Kristie Lindsey Rose
- Department of Biochemistry and Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Brandt F Eichman
- Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - James M Dewar
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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3
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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: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [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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4
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Brosh RM, Trakselis MA. Fine-tuning of the replisome: Mcm10 regulates fork progression and regression. Cell Cycle 2019; 18:1047-1055. [PMID: 31014174 DOI: 10.1080/15384101.2019.1609833] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Several decades of research have identified Mcm10 hanging around the replisome making several critical contacts with a number of proteins but with no real disclosed function. Recently, the O'Donnell laboratory has been better able to map the interactions of Mcm10 with a larger Cdc45/GINS/MCM (CMG) unwinding complex placing it at the front of the replication fork. They have shown biochemically that Mcm10 has the impressive ability to strip off single-strand binding protein (RPA) and reanneal complementary DNA strands. This has major implications in controlling DNA unwinding speed as well as responding to various situations where fork reversal is needed. This work opens up a number of additional facets discussed here revolving around accessing the DNA junction for different molecular purposes within a crowded replisome. Abbreviations: alt-NHEJ: Alternative Nonhomologous End-Joining; CC: Coli-Coil motif; CMG: Cdc45/GINS/MCM2-7; CMGM: Cdc45/GINS/Mcm2-7/Mcm10; CPT: Camptothecin; CSB: Cockayne Syndrome Group B protein; CTD: C-Terminal Domain; DSB: Double-Strand Break; DSBR: Double-Strand Break Repair; dsDNA: Double-Stranded DNA; GINS: go-ichi-ni-san, Sld5-Psf1-Psf2-Psf3; HJ Dis: Holliday Junction dissolution; HJ Res: Holliday Junction resolution; HR: Homologous Recombination; ICL: Interstrand Cross-Link; ID: Internal Domain; MCM: Minichromosomal Maintenance; ND: Not Determined; NTD: N-Terminal Domain; PCNA: Proliferating Cell Nuclear Antigen; RPA: Replication Protein A; SA: Strand Annealing; SE: Strand Exchange; SEW: Steric Exclusion and Wrapping; ssDNA: Single-Stranded DNA; TCR: Transcription-Coupled Repair; TOP1: Topoisomerase.
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Affiliation(s)
- Robert M Brosh
- a Laboratory of Molecular Gerontology , National Institute on Aging, National Institutes of Health , Baltimore , MD USA
| | - Michael A Trakselis
- b Department of Chemistry and Biochemistry , Baylor University , Waco , TX , USA
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5
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Mcm10 has potent strand-annealing activity and limits translocase-mediated fork regression. Proc Natl Acad Sci U S A 2018; 116:798-803. [PMID: 30598452 PMCID: PMC6338834 DOI: 10.1073/pnas.1819107116] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Fork regression is a way of circumventing or dealing with DNA lesions and is important to genome integrity. Fork regression is performed by double-strand DNA ATPases that initially cause newly synthesized strands to unpair from the parental strands, followed by pairing of the new strands and reversal of the fork. This study shows that Mcm10, an essential replication factor, efficiently anneals complementary strands and also inhibits fork regression by SMARCAL1. Moreover, the study localizes the Mcm10 DNA-binding domain to the N-terminal domains of the replicative CMG helicase at the forked nexus. Thus, forks that are unimpeded would contain Mcm10 at a strategic position where its DNA-binding and/or annealing function may block fork regression enzymes and thereby protect active forks from becoming reversed. The 11-subunit eukaryotic replicative helicase CMG (Cdc45, Mcm2-7, GINS) tightly binds Mcm10, an essential replication protein in all eukaryotes. Here we show that Mcm10 has a potent strand-annealing activity both alone and in complex with CMG. CMG-Mcm10 unwinds and then reanneals single strands soon after they have been unwound in vitro. Given the DNA damage and replisome instability associated with loss of Mcm10 function, we examined the effect of Mcm10 on fork regression. Fork regression requires the unwinding and pairing of newly synthesized strands, performed by a specialized class of ATP-dependent DNA translocases. We show here that Mcm10 inhibits fork regression by the well-known fork reversal enzyme SMARCAL1. We propose that Mcm10 inhibits the unwinding of nascent strands to prevent fork regression at normal unperturbed replication forks, either by binding the fork junction to form a block to SMARCAL1 or by reannealing unwound nascent strands to their parental template. Analysis of the CMG-Mcm10 complex by cross-linking mass spectrometry reveals Mcm10 interacts with six CMG subunits, with the DNA-binding region of Mcm10 on the N-face of CMG. This position on CMG places Mcm10 at the fork junction, consistent with a role in regulating fork regression.
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6
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Kang S, Kang MS, Ryu E, Myung K. Eukaryotic DNA replication: Orchestrated action of multi-subunit protein complexes. Mutat Res 2018; 809:58-69. [PMID: 28501329 DOI: 10.1016/j.mrfmmm.2017.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/13/2017] [Accepted: 04/30/2017] [Indexed: 06/07/2023]
Abstract
Genome duplication is an essential process to preserve genetic information between generations. The eukaryotic cell cycle is composed of functionally distinct phases: G1, S, G2, and M. One of the key replicative proteins that participate at every stage of DNA replication is the Mcm2-7 complex, a replicative helicase. In the G1 phase, inactive Mcm2-7 complexes are loaded on the replication origins by replication-initiator proteins, ORC and Cdc6. Two kinases, S-CDK and DDK, convert the inactive origin-loaded Mcm2-7 complex to an active helicase, the CMG complex in the S phase. The activated CMG complex begins DNA unwinding and recruits enzymes essential for DNA synthesis to assemble a replisome at the replication fork. After completion of DNA synthesis, the inactive CMG complex on the replicated DNA is removed from chromatin to terminate DNA replication. In this review, we will discuss the structure, function, and regulation of the molecular machines involved in each step of DNA replication.
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Affiliation(s)
- Sukhyun Kang
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea.
| | - Mi-Sun Kang
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea
| | - Eunjin Ryu
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea; School of Life Sciences, Ulsan National Institute for Science and Technology, Ulsan 44919, Republic of Korea
| | - Kyungjae Myung
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea; School of Life Sciences, Ulsan National Institute for Science and Technology, Ulsan 44919, Republic of Korea
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7
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Perez-Arnaiz P, Bruck I, Colbert MK, Kaplan DL. An intact Mcm10 coiled-coil interaction surface is important for origin melting, helicase assembly and the recruitment of Pol-α to Mcm2-7. Nucleic Acids Res 2017; 45:7261-7275. [PMID: 28510759 PMCID: PMC5499591 DOI: 10.1093/nar/gkx438] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 05/03/2017] [Indexed: 11/16/2022] Open
Abstract
Mcm10 is an essential eukaryotic factor required for DNA replication. The replication fork helicase is composed of Cdc45, Mcm2–7 and GINS (CMG). DDK is an S-phase-specific kinase required for replication initiation, and the DNA primase-polymerase in eukaryotes is pol α. Mcm10 forms oligomers in vitro, mediated by the coiled-coil domain at the N-terminal region of the protein. We characterized an Mcm10 mutant at the N-terminal Domain (NTD), Mcm10-4A, defective for self-interaction. We found that the Mcm10-4A mutant was defective for stimulating DDK phosphorylation of Mcm2, binding to eighty-nucleotide ssDNA, and recruiting pol α to Mcm2–7 in vitro. Expression of wild-type levels of mcm10-4A resulted in severe growth and DNA replication defects in budding yeast cells, with diminished DDK phosphorylation of Mcm2. We then expressed the mcm10-4A in mcm5-bob1 mutant cells to bypass the defects mediated by diminished stimulation of DDK phosphorylation of Mcm2. Expression of wild-type levels of mcm10-4A in mcm5-bob1 mutant cells resulted in severe growth and DNA replication defects, along with diminished RPA signal at replication origins. We also detected diminished GINS and pol-α recruitment to the Mcm2–7 complex. We conclude that an intact Mcm10 coiled-coil interaction surface is important for origin melting, helicase assembly, and the recruitment of pol α to Mcm2–7.
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Affiliation(s)
- Patricia Perez-Arnaiz
- Florida State University College of Medicine, Department of Biomedical Sciences, Tallahassee, FL 32306, USA
| | - Irina Bruck
- Florida State University College of Medicine, Department of Biomedical Sciences, Tallahassee, FL 32306, USA
| | - Max K Colbert
- Florida State University College of Medicine, Department of Biomedical Sciences, Tallahassee, FL 32306, USA
| | - Daniel L Kaplan
- Florida State University College of Medicine, Department of Biomedical Sciences, Tallahassee, FL 32306, USA
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8
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Izumi M, Mizuno T, Yanagi KI, Sugimura K, Okumura K, Imamoto N, Abe T, Hanaoka F. The Mcm2-7-interacting domain of human mini-chromosome maintenance 10 (Mcm10) protein is important for stable chromatin association and origin firing. J Biol Chem 2017. [PMID: 28646110 DOI: 10.1074/jbc.m117.779371] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The protein mini-chromosome maintenance 10 (Mcm10) was originally identified as an essential yeast protein in the maintenance of mini-chromosome plasmids. Subsequently, Mcm10 has been shown to be required for both initiation and elongation during chromosomal DNA replication. However, it is not fully understood how the multiple functions of Mcm10 are coordinated or how Mcm10 interacts with other factors at replication forks. Here, we identified and characterized the Mcm2-7-interacting domain in human Mcm10. The interaction with Mcm2-7 required the Mcm10 domain that contained amino acids 530-655, which overlapped with the domain required for the stable retention of Mcm10 on chromatin. Expression of truncated Mcm10 in HeLa cells depleted of endogenous Mcm10 via siRNA revealed that the Mcm10 conserved domain (amino acids 200-482) is essential for DNA replication, whereas both the conserved and the Mcm2-7-binding domains were required for its full activity. Mcm10 depletion reduced the initiation frequency of DNA replication and interfered with chromatin loading of replication protein A, DNA polymerase (Pol) α, and proliferating cell nuclear antigen, whereas the chromatin loading of Cdc45 and Pol ϵ was unaffected. These results suggest that human Mcm10 is bound to chromatin through the interaction with Mcm2-7 and is primarily involved in the initiation of DNA replication after loading of Cdc45 and Pol ϵ.
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Affiliation(s)
- Masako Izumi
- Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan.
| | - Takeshi Mizuno
- Cellular Dynamics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | | | - Kazuto Sugimura
- Department of Life Science, Graduate School of Bioresources, Mie University, Tsu, Mie 514-8507, Japan
| | - Katsuzumi Okumura
- Department of Life Science, Graduate School of Bioresources, Mie University, Tsu, Mie 514-8507, Japan
| | - Naoko Imamoto
- Cellular Dynamics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Tomoko Abe
- Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan
| | - Fumio Hanaoka
- Department of Life Science, Faculty of Science, Gakushuin University, Tokyo 171-8588, Japan; Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba, Ibaraki 305-8577, Japan
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9
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Mcm10: A Dynamic Scaffold at Eukaryotic Replication Forks. Genes (Basel) 2017; 8:genes8020073. [PMID: 28218679 PMCID: PMC5333062 DOI: 10.3390/genes8020073] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/09/2017] [Accepted: 02/09/2017] [Indexed: 12/13/2022] Open
Abstract
To complete the duplication of large genomes efficiently, mechanisms have evolved that coordinate DNA unwinding with DNA synthesis and provide quality control measures prior to cell division. Minichromosome maintenance protein 10 (Mcm10) is a conserved component of the eukaryotic replisome that contributes to this process in multiple ways. Mcm10 promotes the initiation of DNA replication through direct interactions with the cell division cycle 45 (Cdc45)-minichromosome maintenance complex proteins 2-7 (Mcm2-7)-go-ichi-ni-san GINS complex proteins, as well as single- and double-stranded DNA. After origin firing, Mcm10 controls replication fork stability to support elongation, primarily facilitating Okazaki fragment synthesis through recruitment of DNA polymerase-α and proliferating cell nuclear antigen. Based on its multivalent properties, Mcm10 serves as an essential scaffold to promote DNA replication and guard against replication stress. Under pathological conditions, Mcm10 is often dysregulated. Genetic amplification and/or overexpression of MCM10 are common in cancer, and can serve as a strong prognostic marker of poor survival. These findings are compatible with a heightened requirement for Mcm10 in transformed cells to overcome limitations for DNA replication dictated by altered cell cycle control. In this review, we highlight advances in our understanding of when, where and how Mcm10 functions within the replisome to protect against barriers that cause incomplete replication.
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10
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Chadha GS, Gambus A, Gillespie PJ, Blow JJ. Xenopus Mcm10 is a CDK-substrate required for replication fork stability. Cell Cycle 2016; 15:2183-2195. [PMID: 27327991 PMCID: PMC4993430 DOI: 10.1080/15384101.2016.1199305] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 12/17/2022] Open
Abstract
During S phase, following activation of the S phase CDKs and the DBF4-dependent kinases (DDK), double hexamers of Mcm2-7 at licensed replication origins are activated to form the core replicative helicase. Mcm10 is one of several proteins that have been implicated from work in yeasts to play a role in forming a mature replisome during the initiation process. Mcm10 has also been proposed to play a role in promoting replisome stability after initiation has taken place. The role of Mcm10 is particularly unclear in metazoans, where conflicting data has been presented. Here, we investigate the role and regulation of Mcm10 in Xenopus egg extracts. We show that Xenopus Mcm10 is recruited to chromatin late in the process of replication initiation and this requires prior action of DDKs and CDKs. We also provide evidence that Mcm10 is a CDK substrate but does not need to be phosphorylated in order to associate with chromatin. We show that in extracts depleted of more than 99% of Mcm10, the bulk of DNA replication still occurs, suggesting that Mcm10 is not required for the process of replication initiation. However, in extracts depleted of Mcm10, the replication fork elongation rate is reduced. Furthermore, the absence of Mcm10 or its phosphorylation by CDK results in instability of replisome proteins on DNA, which is particularly important under conditions of replication stress.
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Affiliation(s)
- Gaganmeet Singh Chadha
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| | - Agnieszka Gambus
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| | - Peter J Gillespie
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| | - J Julian Blow
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
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11
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Douglas ME, Diffley JFX. Recruitment of Mcm10 to Sites of Replication Initiation Requires Direct Binding to the Minichromosome Maintenance (MCM) Complex. J Biol Chem 2016; 291:5879-5888. [PMID: 26719337 PMCID: PMC4786722 DOI: 10.1074/jbc.m115.707802] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 12/28/2015] [Indexed: 01/11/2023] Open
Abstract
Mcm10 is required for the initiation of eukaryotic DNA replication and contributes in some unknown way to the activation of the Cdc45-MCM-GINS (CMG) helicase. How Mcm10 is localized to sites of replication initiation is unclear, as current models indicate that direct binding to minichromosome maintenance (MCM) plays a role, but the details and functional importance of this interaction have not been determined. Here, we show that purified Mcm10 can bind both DNA-bound double hexamers and soluble single hexamers of MCM. The binding of Mcm10 to MCM requires the Mcm10 C terminus. Moreover, the binding site for Mcm10 on MCM includes the Mcm2 and Mcm6 subunits and overlaps that for the loading factor Cdt1. Whether Mcm10 recruitment to replication origins depends on CMG helicase assembly has been unclear. We show that Mcm10 recruitment occurs via two modes: low affinity recruitment in the absence of CMG assembly ("G1-like") and high affinity recruitment when CMG assembly takes place ("S-phase-like"). Mcm10 that cannot bind directly to MCM is defective in both modes of recruitment and is unable to support DNA replication. These findings indicate that Mcm10 is localized to replication initiation sites by directly binding MCM through the Mcm10 C terminus.
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Affiliation(s)
- Max E Douglas
- From The Francis Crick Institute, Clare Hall Laboratory, South Mimms, Hertfordshire EN6 3LD, United Kingdom
| | - John F X Diffley
- From The Francis Crick Institute, Clare Hall Laboratory, South Mimms, Hertfordshire EN6 3LD, United Kingdom.
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12
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Waugh DS. Crystal structures of MBP fusion proteins. Protein Sci 2016; 25:559-71. [PMID: 26682969 DOI: 10.1002/pro.2863] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 12/16/2015] [Indexed: 02/06/2023]
Abstract
Although chaperone-assisted protein crystallization remains a comparatively rare undertaking, the number of crystal structures of polypeptides fused to maltose-binding protein (MBP) that have been deposited in the Protein Data Bank (PDB) has grown dramatically during the past decade. Altogether, 102 fusion protein structures were detected by Basic Local Alignment Search Tool (BLAST) analysis. Collectively, these structures comprise a range of sizes, space groups, and resolutions that are typical of the PDB as a whole. While most of these MBP fusion proteins were equipped with short inter-domain linkers to increase their rigidity, fusion proteins with long linkers have also been crystallized. In some cases, surface entropy reduction mutations in MBP appear to have facilitated the formation of crystals. A comparison of the structures of fused and unfused proteins, where both are available, reveals that MBP-mediated structural distortions are very rare.
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Affiliation(s)
- David S Waugh
- Protein Engineering Section, Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, P.O. Box B, Frederick, Maryland, 21702-1201
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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] [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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Vo N, Taga A, Inaba Y, Yoshida H, Cotterill S, Yamaguchi M. Drosophila Mcm10 is required for DNA replication and differentiation in the compound eye. PLoS One 2014; 9:e93450. [PMID: 24686397 PMCID: PMC3970972 DOI: 10.1371/journal.pone.0093450] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/03/2014] [Indexed: 11/18/2022] Open
Abstract
Mini chromosome maintenance 10 (Mcm10) is an essential protein, which is conserved from S. cerevisiae to Drosophila and human, and is required for the initiation of DNA replication. Knockdown of Drosophila Mcm10 (dMcm10) by RNA interference in eye imaginal discs induces abnormal eye morphology (rough eye phenotype), and the number of ommatidia is decreased in adult eyes. We also observed a delay in the S phase and M phase in eye discs of dMcm10 knockdown fly lines. These results show important roles for dMcm10 in the progression of S and M phases. Furthermore, genome damage and apoptosis were induced by dMcm10 knockdown in eye imaginal discs. Surprisingly, when we used deadpan-lacZ and klingon-lacZ enhancer trap lines to monitor the photoreceptor cells in eye discs, knockdown of dMcm10 by the GMR-GAL4 driver reduced the signals of R7 photoreceptor cells. These data suggest an involvement of dMcm10 in R7 cell differentiation. This involvement appears to be independent of the apoptosis induced by dMcm10 knockdown. Together, these results suggest that dMcm10 knockdown has an effect on DNA replication and R7 cell differentiation.
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Affiliation(s)
- Nicole Vo
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
- Insect Biomedical Research Center, Kyoto Institute of Technology, Kyoto, Japan
| | - Ayano Taga
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
- Insect Biomedical Research Center, Kyoto Institute of Technology, Kyoto, Japan
| | - Yasuhiro Inaba
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
- Insect Biomedical Research Center, Kyoto Institute of Technology, Kyoto, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
- Insect Biomedical Research Center, Kyoto Institute of Technology, Kyoto, Japan
| | - Sue Cotterill
- Department of Basic Medical Sciences, St Georges University of London, London, United Kingdom
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
- Insect Biomedical Research Center, Kyoto Institute of Technology, Kyoto, Japan
- * E-mail:
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15
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Thu YM, Bielinsky AK. MCM10: one tool for all-Integrity, maintenance and damage control. Semin Cell Dev Biol 2014; 30:121-30. [PMID: 24662891 DOI: 10.1016/j.semcdb.2014.03.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 03/10/2014] [Indexed: 01/16/2023]
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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