1
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Cho T, Hoeg L, Setiaputra D, Durocher D. NFATC2IP is a mediator of SUMO-dependent genome integrity. Genes Dev 2024; 38:233-252. [PMID: 38503515 PMCID: PMC11065178 DOI: 10.1101/gad.350914.123] [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: 07/05/2023] [Accepted: 03/04/2024] [Indexed: 03/21/2024]
Abstract
The post-translational modification of proteins by SUMO is crucial for cellular viability and mammalian development in part due to the contribution of SUMOylation to genome duplication and repair. To investigate the mechanisms underpinning the essential function of SUMO, we undertook a genome-scale CRISPR/Cas9 screen probing the response to SUMOylation inhibition. This effort identified 130 genes whose disruption reduces or enhances the toxicity of TAK-981, a clinical-stage inhibitor of the SUMO E1-activating enzyme. Among the strongest hits, we validated and characterized NFATC2IP, an evolutionarily conserved protein related to the fungal Esc2 and Rad60 proteins that harbors tandem SUMO-like domains. Cells lacking NFATC2IP are viable but are hypersensitive to SUMO E1 inhibition, likely due to the accumulation of mitotic chromosome bridges and micronuclei. NFATC2IP primarily acts in interphase and associates with nascent DNA, suggesting a role in the postreplicative resolution of replication or recombination intermediates. Mechanistically, NFATC2IP interacts with the SMC5/6 complex and UBC9, the SUMO E2, via its first and second SUMO-like domains, respectively. AlphaFold-Multimer modeling suggests that NFATC2IP positions and activates the UBC9-NSMCE2 complex, the SUMO E3 ligase associated with SMC5/SMC6. We conclude that NFATC2IP is a key mediator of SUMO-dependent genomic integrity that collaborates with the SMC5/6 complex.
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Affiliation(s)
- Tiffany Cho
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Lisa Hoeg
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Dheva Setiaputra
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Daniel Durocher
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada;
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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2
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Roy S, Adhikary H, D’Amours D. The SMC5/6 complex: folding chromosomes back into shape when genomes take a break. Nucleic Acids Res 2024; 52:2112-2129. [PMID: 38375830 PMCID: PMC10954462 DOI: 10.1093/nar/gkae103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/28/2024] [Accepted: 02/01/2024] [Indexed: 02/21/2024] Open
Abstract
High-level folding of chromatin is a key determinant of the shape and functional state of chromosomes. During cell division, structural maintenance of chromosome (SMC) complexes such as condensin and cohesin ensure large-scale folding of chromatin into visible chromosomes. In contrast, the SMC5/6 complex plays more local and context-specific roles in the structural organization of interphase chromosomes with important implications for health and disease. Recent advances in single-molecule biophysics and cryo-electron microscopy revealed key insights into the architecture of the SMC5/6 complex and how interactions connecting the complex to chromatin components give rise to its unique repertoire of interphase functions. In this review, we provide an integrative view of the features that differentiates the SMC5/6 complex from other SMC enzymes and how these enable dramatic reorganization of DNA folding in space during DNA repair reactions and other genome transactions. Finally, we explore the mechanistic basis for the dynamic targeting of the SMC5/6 complex to damaged chromatin and its crucial role in human health.
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Affiliation(s)
- Shamayita Roy
- Ottawa Institute of Systems Biology, Department of Cellular and Molecular Medicine, University of Ottawa, Roger Guindon Hall, 451 Smyth Rd, Ottawa, ON K1H 8M5, Canada
| | - Hemanta Adhikary
- Ottawa Institute of Systems Biology, Department of Cellular and Molecular Medicine, University of Ottawa, Roger Guindon Hall, 451 Smyth Rd, Ottawa, ON K1H 8M5, Canada
| | - Damien D’Amours
- Ottawa Institute of Systems Biology, Department of Cellular and Molecular Medicine, University of Ottawa, Roger Guindon Hall, 451 Smyth Rd, Ottawa, ON K1H 8M5, Canada
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3
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Xu MJ, Jordan PW. SMC5/6 Promotes Replication Fork Stability via Negative Regulation of the COP9 Signalosome. Int J Mol Sci 2024; 25:952. [PMID: 38256025 PMCID: PMC10815603 DOI: 10.3390/ijms25020952] [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: 12/04/2023] [Revised: 01/06/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
It is widely accepted that DNA replication fork stalling is a common occurrence during cell proliferation, but there are robust mechanisms to alleviate this and ensure DNA replication is completed prior to chromosome segregation. The SMC5/6 complex has consistently been implicated in the maintenance of replication fork integrity. However, the essential role of the SMC5/6 complex during DNA replication in mammalian cells has not been elucidated. In this study, we investigate the molecular consequences of SMC5/6 loss at the replication fork in mouse embryonic stem cells (mESCs), employing the auxin-inducible degron (AID) system to deplete SMC5 acutely and reversibly in the defined cellular contexts of replication fork stall and restart. In SMC5-depleted cells, we identify a defect in the restart of stalled replication forks, underpinned by excess MRE11-mediated fork resection and a perturbed localization of fork protection factors to the stalled fork. Previously, we demonstrated a physical and functional interaction of SMC5/6 with the COP9 signalosome (CSN), a cullin deneddylase that enzymatically regulates cullin ring ligase (CRL) activity. Employing a combination of DNA fiber techniques, the AID system, small-molecule inhibition assays, and immunofluorescence microscopy analyses, we show that SMC5/6 promotes the localization of fork protection factors to stalled replication forks by negatively modulating the COP9 signalosome (CSN). We propose that the SMC5/6-mediated modulation of the CSN ensures that CRL activity and their roles in DNA replication fork stabilization are maintained to allow for efficient replication fork restart when a replication fork stall is alleviated.
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Affiliation(s)
- Michelle J. Xu
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Philip W. Jordan
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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4
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O’Brien MP, Pryzhkova MV, Lake EMR, Mandino F, Shen X, Karnik R, Atkins A, Xu MJ, Ji W, Konstantino M, Brueckner M, Ment LR, Khokha MK, Jordan PW. SMC5 Plays Independent Roles in Congenital Heart Disease and Neurodevelopmental Disability. Int J Mol Sci 2023; 25:430. [PMID: 38203602 PMCID: PMC10779392 DOI: 10.3390/ijms25010430] [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: 11/30/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
Up to 50% of patients with severe congenital heart disease (CHD) develop life-altering neurodevelopmental disability (NDD). It has been presumed that NDD arises in CHD cases because of hypoxia before, during, or after cardiac surgery. Recent studies detected an enrichment in de novo mutations in CHD and NDD, as well as significant overlap between CHD and NDD candidate genes. However, there is limited evidence demonstrating that genes causing CHD can produce NDD independent of hypoxia. A patient with hypoplastic left heart syndrome and gross motor delay presented with a de novo mutation in SMC5. Modeling mutation of smc5 in Xenopus tropicalis embryos resulted in reduced heart size, decreased brain length, and disrupted pax6 patterning. To evaluate the cardiac development, we induced the conditional knockout (cKO) of Smc5 in mouse cardiomyocytes, which led to the depletion of mature cardiomyocytes and abnormal contractility. To test a role for Smc5 specifically in the brain, we induced cKO in the mouse central nervous system, which resulted in decreased brain volume, and diminished connectivity between areas related to motor function but did not affect vascular or brain ventricular volume. We propose that genetic factors, rather than hypoxia alone, can contribute when NDD and CHD cases occur concurrently.
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Affiliation(s)
- Matthew P. O’Brien
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Marina V. Pryzhkova
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA
- Department of Biochemistry and Molecular Biology, Uniformed Services, University of the Health Sciences, 4301 Jones Bridge Rd, Bethesda, MD 20814, USA
| | - Evelyn M. R. Lake
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Francesca Mandino
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Xilin Shen
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Ruchika Karnik
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Alisa Atkins
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA
| | - Michelle J. Xu
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA
| | - Weizhen Ji
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Monica Konstantino
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Martina Brueckner
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Laura R. Ment
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Mustafa K. Khokha
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Philip W. Jordan
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA
- Department of Biochemistry and Molecular Biology, Uniformed Services, University of the Health Sciences, 4301 Jones Bridge Rd, Bethesda, MD 20814, USA
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5
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Soliman TN, Keifenheim D, Parker PJ, Clarke DJ. Cell cycle responses to Topoisomerase II inhibition: Molecular mechanisms and clinical implications. J Cell Biol 2023; 222:e202209125. [PMID: 37955972 PMCID: PMC10641588 DOI: 10.1083/jcb.202209125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
DNA Topoisomerase IIA (Topo IIA) is an enzyme that alters the topological state of DNA and is essential for the separation of replicated sister chromatids and the integrity of cell division. Topo IIA dysfunction activates cell cycle checkpoints, resulting in arrest in either the G2-phase or metaphase of mitosis, ultimately triggering the abscission checkpoint if non-disjunction persists. These events, which directly or indirectly monitor the activity of Topo IIA, have become of major interest as many cancers have deficiencies in Topoisomerase checkpoints, leading to genome instability. Recent studies into how cells sense Topo IIA dysfunction and respond by regulating cell cycle progression demonstrate that the Topo IIA G2 checkpoint is distinct from the G2-DNA damage checkpoint. Likewise, in mitosis, the metaphase Topo IIA checkpoint is separate from the spindle assembly checkpoint. Here, we integrate mechanistic knowledge of Topo IIA checkpoints with the current understanding of how cells regulate progression through the cell cycle to accomplish faithful genome transmission and discuss the opportunities this offers for therapy.
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Affiliation(s)
- Tanya N. Soliman
- Barts Cancer Institute, Queen Mary University London, London, UK
| | - Daniel Keifenheim
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | | | - Duncan J. Clarke
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
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6
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Peng XP, Zhao X. The multi-functional Smc5/6 complex in genome protection and disease. Nat Struct Mol Biol 2023; 30:724-734. [PMID: 37336994 PMCID: PMC10372777 DOI: 10.1038/s41594-023-01015-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/05/2023] [Indexed: 06/21/2023]
Abstract
Structural maintenance of chromosomes (SMC) complexes are ubiquitous genome regulators with a wide range of functions. Among the three types of SMC complexes in eukaryotes, cohesin and condensin fold the genome into different domains and structures, while Smc5/6 plays direct roles in promoting chromosomal replication and repair and in restraining pathogenic viral extra-chromosomal DNA. The importance of Smc5/6 for growth, genotoxin resistance and host defense across species is highlighted by its involvement in disease prevention in plants and animals. Accelerated progress in recent years, including structural and single-molecule studies, has begun to provide greater insights into the mechanisms underlying Smc5/6 functions. Here we integrate a broad range of recent studies on Smc5/6 to identify emerging features of this unique SMC complex and to explain its diverse cellular functions and roles in disease pathogenesis. We also highlight many key areas requiring further investigation for achieving coherent views of Smc5/6-driven mechanisms.
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Affiliation(s)
- Xiao P Peng
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xiaolan Zhao
- Molecular Biology Program, Sloan Kettering Cancer Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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7
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Regulation of the mitotic chromosome folding machines. Biochem J 2022; 479:2153-2173. [PMID: 36268993 DOI: 10.1042/bcj20210140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 09/30/2022] [Accepted: 10/03/2022] [Indexed: 11/17/2022]
Abstract
Over the last several years enormous progress has been made in identifying the molecular machines, including condensins and topoisomerases that fold mitotic chromosomes. The discovery that condensins generate chromatin loops through loop extrusion has revolutionized, and energized, the field of chromosome folding. To understand how these machines fold chromosomes with the appropriate dimensions, while disentangling sister chromatids, it needs to be determined how they are regulated and deployed. Here, we outline the current understanding of how these machines and factors are regulated through cell cycle dependent expression, chromatin localization, activation and inactivation through post-translational modifications, and through associations with each other, with other factors and with the chromatin template itself. There are still many open questions about how condensins and topoisomerases are regulated but given the pace of progress in the chromosome folding field, it seems likely that many of these will be answered in the years ahead.
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8
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Wu Z, Wang L, Wang X, Sun Y, Li H, Zhang Z, Ren C, Zhang X, Li S, Lu J, Xu L, Yue X, Hong Y, Li Q, Zhu H, Gong Y, Gao C, Hu H, Gao L, Liang X, Ma C. cccDNA Surrogate MC-HBV-Based Screen Identifies Cohesin Complex as a Novel HBV Restriction Factor. Cell Mol Gastroenterol Hepatol 2022; 14:1177-1198. [PMID: 35987451 PMCID: PMC9579331 DOI: 10.1016/j.jcmgh.2022.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 08/10/2022] [Accepted: 08/10/2022] [Indexed: 01/31/2023]
Abstract
BACKGROUND & AIMS Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV), existing as a stable minichromosome in the hepatocyte, is responsible for persistent HBV infection. Maintenance and sustained replication of cccDNA require its interaction with both viral and host proteins. However, the cccDNA-interacting host factors that limit HBV replication remain elusive. METHODS Minicircle HBV (MC-HBV), a recombinant cccDNA, was constructed based on chimeric intron and minicircle DNA technology. By mass spectrometry based on pull-down with biotinylated MC-HBV, the cccDNA-hepatocyte interaction profile was mapped. HBV replication was assessed in different cell models that support cccDNA formation. RESULTS MC-HBV supports persistent HBV replication and mimics the cccDNA minichromosome. The MC-HBV-based screen identified cohesin complex as a cccDNA binding host factor, leading to reduced HBV replication. Mechanistically, with the help of CCCTC-binding factor (CTCF), which has specific binding sites on cccDNA, cohesin loads on cccDNA and reshapes cccDNA confirmation to prevent RNA polymerase II enrichment. Interestingly, HBV X protein transcriptionally reduces structural maintenance of chromosomes complex expression to partially relieve the inhibitory role of the cohesin complex on HBV replication. CONCLUSIONS Our data not only provide a feasible approach to explore cccDNA-binding factors, but also identify cohesin/CTCF complex as a critical host restriction factor for cccDNA-driven HBV replication. These findings provide a novel insight into cccDNA-host interaction and targeted therapeutic intervention for HBV infection.
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Affiliation(s)
- Zhuanchang Wu
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Liyuan Wang
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Xin Wang
- College of Agriculture and Forestry, Linyi University, Linyi, Shandong, China
| | - Yang Sun
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Haoran Li
- College of Agriculture and Forestry, Linyi University, Linyi, Shandong, China
| | - Zhaoying Zhang
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Caiyue Ren
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Xiaohui Zhang
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Genetics, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Shuangjie Li
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Jinghui Lu
- Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Leiqi Xu
- Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Xuetian Yue
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Yue Hong
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong, China
| | - Qiang Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong, China
| | - Haizhen Zhu
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, Hunan, China
| | - Yaoqin Gong
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Genetics, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Chengjiang Gao
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Huili Hu
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Genetics, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Lifen Gao
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Xiaohong Liang
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Chunhong Ma
- Key Laboratory for Experimental Teratology of Ministry of Education and Dept. Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China,Correspondence Address correspondence to: Chunhong Ma, PhD, Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, 44 Wenhua Xi Road, Jinan, Shandong, 250012 China.
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Wang J, Bando M, Shirahige K, Nakato R. Large-scale multi-omics analysis suggests specific roles for intragenic cohesin in transcriptional regulation. Nat Commun 2022; 13:3218. [PMID: 35680859 PMCID: PMC9184728 DOI: 10.1038/s41467-022-30792-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 05/14/2022] [Indexed: 12/19/2022] Open
Abstract
Cohesin, an essential protein complex for chromosome segregation, regulates transcription through a variety of mechanisms. It is not a trivial task to assign diverse cohesin functions. Moreover, the context-specific roles of cohesin-mediated interactions, especially on intragenic regions, have not been thoroughly investigated. Here we perform a comprehensive characterization of cohesin binding sites in several human cell types. We integrate epigenomic, transcriptomic and chromatin interaction data to explore the context-specific functions of intragenic cohesin related to gene activation. We identify a specific subset of cohesin binding sites, decreased intragenic cohesin sites (DICs), which are negatively correlated with transcriptional regulation. A subgroup of DICs is enriched with enhancer markers and RNA polymerase II, while the others are more correlated to chromatin architecture. DICs are observed in various cell types, including cells from patients with cohesinopathy. We also implement machine learning to our data and identified genomic features for isolating DICs from all cohesin sites. These results suggest a previously unidentified function of cohesin on intragenic regions for transcriptional regulation.
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Affiliation(s)
- Jiankang Wang
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
- Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masashige Bando
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | - Katsuhiko Shirahige
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
- Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Ryuichiro Nakato
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan.
- Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
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10
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Sekiba K, Otsuka M, Funato K, Miyakawa Y, Tanaka E, Seimiya T, Yamagami M, Tsutsumi T, Okushin K, Miyakawa K, Ryo A, Koike K. HBx-induced degradation of Smc5/6 complex impairs homologous recombination-mediated repair of damaged DNA. J Hepatol 2022; 76:53-62. [PMID: 34478763 DOI: 10.1016/j.jhep.2021.08.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 07/25/2021] [Accepted: 08/11/2021] [Indexed: 12/30/2022]
Abstract
BACKGROUND & AIMS HBV causes hepatocellular carcinoma (HCC). While it was recently shown that the ability of HBV X protein (HBx) to impair the Smc5/6 (structural maintenance of chromosome 5/6) complex is important for viral transcription, HBx is also a potent driver of HCC. However, the mechanism by which HBx expression induces hepatocarcinogenesis is unclear. METHODS Degradation of the Smc5/6 complex and accumulation of DNA damage were observed in both in vivo and in vitro HBV infection models. Rescue experiments were performed using nitazoxanide (NTZ), which inhibits degradation of the Smc5/6 complex by HBx. RESULTS HBx-triggered degradation of the Smc5/6 complex causes impaired homologous recombination (HR) repair of DNA double-strand breaks (DSBs), leading to cellular transformation. We found that DNA damage accumulated in the liver tissue of HBV-infected humanized chimeric mice, HBx-transgenic mice, and human tissues. HBx suppressed the HR repair of DSBs, including that induced by the CRISPR-Cas9 system, in an Smc5/6-dependent manner, which was rescued by restoring the Smc5/6 complex. NTZ restored HR repair in, and colony formation by, HBx-expressing cells. CONCLUSIONS Degradation of the Smc5/6 complex by HBx increases viral transcription and promotes cellular transformation by impairing HR repair of DSBs. LAY SUMMARY The hepatitis B virus expresses a regulatory protein called HBV X protein (or HBx). This protein degrades the Smc5/6 complex in human hepatocytes, which is essential for viral replication. We found that this process also plays a key role in the accumulation of DNA damage, which contributes to HBx-mediated tumorigenesis.
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Affiliation(s)
- Kazuma Sekiba
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Motoyuki Otsuka
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.
| | - Kazuyoshi Funato
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yu Miyakawa
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Eri Tanaka
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Takahiro Seimiya
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Mari Yamagami
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Takeya Tsutsumi
- Division of Infectious Diseases, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Kazuya Okushin
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; Department of Infection Control and Prevention, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Kei Miyakawa
- Department of Microbiology, Yokohama City University School of Medicine, Kanagawa 236-0004, Japan
| | - Akihide Ryo
- Department of Microbiology, Yokohama City University School of Medicine, Kanagawa 236-0004, Japan
| | - Kazuhiko Koike
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
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11
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Li JN, Wang MY, Chen YT, Kuo YL, Chen PS. Expression of SnoRNA U50A Is Associated with Better Prognosis and Prolonged Mitosis in Breast Cancer. Cancers (Basel) 2021; 13:cancers13246304. [PMID: 34944924 PMCID: PMC8699759 DOI: 10.3390/cancers13246304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/22/2021] [Accepted: 11/26/2021] [Indexed: 11/24/2022] Open
Abstract
Simple Summary SnoRNAs are essential for fundamental cellular processes. However, emerging evidence shows that snoRNAs play regulatory roles during cancer progression. The snoRNA U50A (U50A) is a newly-identified putative tumor suppressor, but its clinical and mechanistic impacts in breast cancer remain elusive. In this study, we quantified the copy number of U50A in breast cancer patient tissues and found that a higher level of U50A expression is correlated with better overall survival in breast cancer patients. By utilizing transcriptomic analysis, we demonstrated that U50A prolongs mitosis and reduces colony-forming ability through downregulating mitosis-related genes. Consistent with these in vitro results, breast cancer tissues expressing higher U50A significantly exhibited accumulated mitotic tumor cells and were associated with reduced tumor size. Altogether, this is the first study showing the clinical, cellular, and regulatory impacts of snoRNA U50A in human breast cancer. Abstract Small nucleolar RNAs (snoRNAs) are small noncoding RNAs generally recognized as housekeeping genes. Genomic analysis has shown that snoRNA U50A (U50A) is a candidate tumor suppressor gene deleted in less than 10% of breast cancer patients. To date, the pathological roles of U50A in cancer, including its clinical significance and its regulatory impact at the molecular level, are not well-defined. Here, we quantified the copy number of U50A in human breast cancer tissues. Our results showed that the U50A expression level is correlated with better prognosis in breast cancer patients. Utilizing RNA-sequencing for transcriptomic analysis, we revealed that U50A downregulates mitosis-related genes leading to arrested cancer cell mitosis and suppressed colony-forming ability. Moreover, in support of the impacts of U50A in prolonging mitosis and inhibiting clonogenic activity, breast cancer tissues with higher U50A expression exhibit accumulated mitotic tumor cells. In conclusion, based on the evidence from U50A-downregulated mitosis-related genes, prolonged mitosis, repressed colony-forming ability, and clinical analyses, we demonstrated molecular insights into the pathological impact of snoRNA U50A in human breast cancer.
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Affiliation(s)
- Jie-Ning Li
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan;
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan;
| | - Ming-Yang Wang
- Department of Surgery, National Taiwan University Hospital, Taipei 100, Taiwan;
| | - Yi-Ting Chen
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan;
- Department of Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Yao-Lung Kuo
- Department of Surgery, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Breast Medical Center, National Cheng Kung University Hospital, Tainan 701, Taiwan
- Correspondence: (Y.-L.K.); or (P.-S.C.); Tel.: +886-6-2353535 (ext. 5224) (Y.-L.K.); +886-6-2353535 (ext. 6233) (P.-S.C.); Fax: +886-6-2368549 (Y.-L.K.); +886-6-2363956 (P.-S.C.)
| | - Pai-Sheng Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan;
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan;
- Correspondence: (Y.-L.K.); or (P.-S.C.); Tel.: +886-6-2353535 (ext. 5224) (Y.-L.K.); +886-6-2353535 (ext. 6233) (P.-S.C.); Fax: +886-6-2368549 (Y.-L.K.); +886-6-2363956 (P.-S.C.)
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12
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Jo M, Kusano Y, Hirota T. Unraveling pathologies underlying chromosomal instability in cancers. Cancer Sci 2021; 112:2975-2983. [PMID: 34032342 PMCID: PMC8353923 DOI: 10.1111/cas.14989] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/16/2021] [Accepted: 05/18/2021] [Indexed: 12/11/2022] Open
Abstract
Aneuploidy is a widespread feature of malignant tumors that arises through persistent chromosome mis‐segregation in mitosis associated with a pathological condition called chromosomal instability, or CIN. Since CIN is known to have a causal relationship with poor prognosis accompanying by multi‐drug resistance, tumor relapse, and metastasis, many research groups have endeavored to understand the mechanisms underlying CIN. In this review, we overview possible etiologies of CIN. The key processes to achieve faithful chromosome segregation include the regulation of sister chromatid cohesion, kinetochore‐microtubule attachment, bipolar spindle formation, spindle‐assembly checkpoint, and the activity of separase. Aberrant chromosome structures during DNA replication might also be a potential cause of CIN. Defective regulation in these processes can lead to chromosome mis‐segregation, manifested by lagging chromosomes, and DNA bridges in anaphase, leading to gross chromosome rearrangements. Investigation into the molecular etiologies of CIN should allow us to explore novel strategies to intervene in CIN to control cancers.
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Affiliation(s)
- Minji Jo
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
| | - Yoshiharu Kusano
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
| | - Toru Hirota
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
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13
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Bradley AI, Marsh NM, Borror HR, Mostoller KE, Gama AI, Gardner RG. Acute ethanol stress induces sumoylation of conserved chromatin structural proteins in Saccharomyces cerevisiae. Mol Biol Cell 2021; 32:1121-1133. [PMID: 33788582 PMCID: PMC8351541 DOI: 10.1091/mbc.e20-11-0715] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Stress is ubiquitous to life and can irreparably damage essential biomolecules and organelles in cells. To survive, organisms must sense and adapt to stressful conditions. One highly conserved adaptive stress response is through the posttranslational modification of proteins by the small ubiquitin-like modifier (SUMO). Here, we examine the effects of acute ethanol stress on protein sumoylation in the budding yeast Saccharomyces cerevisiae. We found that cells exhibit a transient sumoylation response after acute exposure to ≤7.5% vol/vol ethanol. By contrast, the sumoylation response becomes chronic at 10% ethanol exposure. Mass spectrometry analyses identified 18 proteins that are sumoylated after acute ethanol exposure, with 15 known to associate with chromatin. Upon further analysis, we found that the chromatin structural proteins Smc5 and Smc6 undergo ethanol-induced sumoylation that depends on the activity of the E3 SUMO ligase Mms21. Using cell-cycle arrest assays, we observed that Smc5 and Smc6 ethanol-induced sumoylation occurs during G1 and G2/M phases but not S phase. Acute ethanol exposure also resulted in the formation of Rad52 foci at levels comparable to Rad52 foci formation after exposure to the DNA alkylating agent methyl methanesulfonate (MMS). MMS exposure is known to induce the intra-S-phase DNA damage checkpoint via Rad53 phosphorylation, but ethanol exposure did not induce Rad53 phosphorylation. Ethanol abrogated the effect of MMS on Rad53 phosphorylation when added simultaneously. From these studies, we propose that acute ethanol exposure induces a change in chromatin leading to sumoylation of specific chromatin structural proteins.
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Affiliation(s)
- Amanda I Bradley
- Department of Pharmacology, University of Washington, Seattle, WA 98195.,Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195
| | - Nicole M Marsh
- Department of Pharmacology, University of Washington, Seattle, WA 98195
| | - Heather R Borror
- Department of Pharmacology, University of Washington, Seattle, WA 98195
| | | | - Amber I Gama
- Department of Pharmacology, University of Washington, Seattle, WA 98195
| | - Richard G Gardner
- Department of Pharmacology, University of Washington, Seattle, WA 98195.,Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195
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14
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Wang H, Liu X, Li G. Explore a novel function of human condensins in cellular senescence. Cell Biosci 2020; 10:147. [PMID: 33375949 PMCID: PMC7772929 DOI: 10.1186/s13578-020-00512-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 12/06/2020] [Indexed: 11/26/2022] Open
Abstract
There are two kinds of condensins in human cells, known as condensin I and condensin II. The canonical roles of condensins are participated in chromosome dynamics, including chromosome condensation and segregation during cell division. Recently, a novel function of human condensins has been found with increasing evidences that they play important roles in cellular senescence. This paper reviewed the research progress of human condensins involved in different types of cellular senescence, mainly oncogene-induced senescence (OIS) and replicative senescence (RS). The future perspectives of human condensins involved in cellular senescence are also discussed.
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Affiliation(s)
- Hongzhen Wang
- School of Life Sciences, Jilin Normal University, 136000, Siping, People's Republic of China. .,Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Sciences, Jilin University, 130012, Changchun, People's Republic of China.
| | - Xin Liu
- School of Life Sciences, Jilin Normal University, 136000, Siping, People's Republic of China
| | - Guiying Li
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Sciences, Jilin University, 130012, Changchun, People's Republic of China
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15
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Gutierrez-Escribano P, Hormeño S, Madariaga-Marcos J, Solé-Soler R, O'Reilly FJ, Morris K, Aicart-Ramos C, Aramayo R, Montoya A, Kramer H, Rappsilber J, Torres-Rosell J, Moreno-Herrero F, Aragon L. Purified Smc5/6 Complex Exhibits DNA Substrate Recognition and Compaction. Mol Cell 2020; 80:1039-1054.e6. [PMID: 33301732 PMCID: PMC7758880 DOI: 10.1016/j.molcel.2020.11.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 10/12/2020] [Accepted: 11/04/2020] [Indexed: 02/03/2023]
Abstract
Eukaryotic SMC complexes, cohesin, condensin, and Smc5/6, use ATP hydrolysis to power a plethora of functions requiring organization and restructuring of eukaryotic chromosomes in interphase and during mitosis. The Smc5/6 mechanism of action and its activity on DNA are largely unknown. Here we purified the budding yeast Smc5/6 holocomplex and characterized its core biochemical and biophysical activities. Purified Smc5/6 exhibits DNA-dependent ATP hydrolysis and SUMO E3 ligase activity. We show that Smc5/6 binds DNA topologically with affinity for supercoiled and catenated DNA templates. Employing single-molecule assays to analyze the functional and dynamic characteristics of Smc5/6 bound to DNA, we show that Smc5/6 locks DNA plectonemes and can compact DNA in an ATP-dependent manner. These results demonstrate that the Smc5/6 complex recognizes DNA tertiary structures involving juxtaposed helices and might modulate DNA topology by plectoneme stabilization and local compaction.
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Affiliation(s)
| | - Silvia Hormeño
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Julene Madariaga-Marcos
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Roger Solé-Soler
- Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Department of Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
| | - Francis J O'Reilly
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany; Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Kyle Morris
- Microscopy Facility, MRC London Institute of Medical Sciences (LMS), Du Cane Road, London W12 0NN, UK
| | - Clara Aicart-Ramos
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Ricardo Aramayo
- Microscopy Facility, MRC London Institute of Medical Sciences (LMS), Du Cane Road, London W12 0NN, UK
| | - Alex Montoya
- Biological Mass Spectrometry and Proteomics Facility, MRC London Institute of Medical Sciences (LMS), Du Cane Road, London W12 0NN, UK
| | - Holger Kramer
- Biological Mass Spectrometry and Proteomics Facility, MRC London Institute of Medical Sciences (LMS), Du Cane Road, London W12 0NN, UK
| | - Juri Rappsilber
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany; Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Jordi Torres-Rosell
- Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Department of Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
| | - Luis Aragon
- Cell Cycle Group, MRC London Institute of Medical Sciences (LMS), Du Cane Road, London W12 0NN, UK.
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16
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Atkins A, Xu MJ, Li M, Rogers NP, Pryzhkova MV, Jordan PW. SMC5/6 is required for replication fork stability and faithful chromosome segregation during neurogenesis. eLife 2020; 9:e61171. [PMID: 33200984 PMCID: PMC7723410 DOI: 10.7554/elife.61171] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 11/16/2020] [Indexed: 12/21/2022] Open
Abstract
Mutations of SMC5/6 components cause developmental defects, including primary microcephaly. To model neurodevelopmental defects, we engineered a mouse wherein Smc5 is conditionally knocked out (cKO) in the developing neocortex. Smc5 cKO mice exhibited neurodevelopmental defects due to neural progenitor cell (NPC) apoptosis, which led to reduction in cortical layer neurons. Smc5 cKO NPCs formed DNA bridges during mitosis and underwent chromosome missegregation. SMC5/6 depletion triggers a CHEK2-p53 DNA damage response, as concomitant deletion of the Trp53 tumor suppressor or Chek2 DNA damage checkpoint kinase rescued Smc5 cKO neurodevelopmental defects. Further assessment using Smc5 cKO and auxin-inducible degron systems demonstrated that absence of SMC5/6 leads to DNA replication stress at late-replicating regions such as pericentromeric heterochromatin. In summary, SMC5/6 is important for completion of DNA replication prior to entering mitosis, which ensures accurate chromosome segregation. Thus, SMC5/6 functions are critical in highly proliferative stem cells during organism development.
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Affiliation(s)
- Alisa Atkins
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public HealthBaltimoreUnited States
| | - Michelle J Xu
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public HealthBaltimoreUnited States
| | - Maggie Li
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public HealthBaltimoreUnited States
| | - Nathaniel P Rogers
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public HealthBaltimoreUnited States
| | - Marina V Pryzhkova
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public HealthBaltimoreUnited States
| | - Philip W Jordan
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public HealthBaltimoreUnited States
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17
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Pryzhkova MV, Xu MJ, Jordan PW. Adaptation of the AID system for stem cell and transgenic mouse research. Stem Cell Res 2020; 49:102078. [PMID: 33202307 PMCID: PMC7784532 DOI: 10.1016/j.scr.2020.102078] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/22/2020] [Accepted: 10/30/2020] [Indexed: 12/14/2022] Open
Abstract
The auxin-inducible degron (AID) system is becoming a widely used method for rapid and reversible degradation of target proteins. This system has been successfully used to study gene and protein functions in eukaryotic cells and common model organisms, such as nematode and fruit fly. To date, applications of the AID system in mammalian stem cell research are limited. Furthermore, standard mouse models harboring the AID system have not been established. Here we have explored the utility of the H11 safe-harbor locus for integration of the TIR1 transgene, an essential component of auxin-based protein degradation system. We have shown that the H11 locus can support constitutive and conditional TIR1 expression in mouse and human embryonic stem cells, as well as in mice. We demonstrate that the AID system can be successfully employed for rapid degradation of stable proteins in embryonic stem cells, which is crucial for investigation of protein functions in quickly changing environments, such as stem cell proliferation and differentiation. As embryonic stem cells possess unlimited proliferative capacity, differentiation potential, and can mimic organ development, we believe that these research tools will be an applicable resource to a broad scientific audience.
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Affiliation(s)
- Marina V Pryzhkova
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Michelle J Xu
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Philip W Jordan
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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18
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The SMC5/6 Complex Represses the Replicative Program of High-Risk Human Papillomavirus Type 31. Pathogens 2020; 9:pathogens9100786. [PMID: 32992873 PMCID: PMC7599729 DOI: 10.3390/pathogens9100786] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/18/2020] [Accepted: 09/23/2020] [Indexed: 01/04/2023] Open
Abstract
The multi-subunit structural maintenance of chromosomes (SMC) 5/6 complex includes SMC6 and non-SMC element (NSE)3. SMC5/6 is essential for homologous recombination DNA repair and functions as an antiviral factor during hepatitis B (HBV) and herpes simplex-1 (HSV-1) viral infections. Intriguingly, SMC5/6 has been found to associate with high-risk human papillomavirus (HPV) E2 regulatory proteins, but the functions of this interaction and its role during HPV infection remain unclear. Here, we further characterize SMC5/6 interactions with HPV-31 E2 and its role in the HPV life cycle. Co-immunoprecipitation (co-IP) revealed that SMC6 interactions with HPV-31 E2 require the E2 transactivation domain, implying that SMC5/6 interacts with full-length E2. Using chromatin immunoprecipitation, we found that SMC6 is present on HPV-31 episomes at E2 binding sites. The depletion of SMC6 and NSE3 increased viral replication and transcription in keratinocytes maintaining episomal HPV-31, indicating that SMC5/6 restricts the viral replicative program. SMC6 interactions with E2 were reduced in the presence of HPV-31 E1, suggesting that SMC6 and E1 compete for E2 binding. Our findings demonstrate SMC5/6 functions as a repressor of the viral replicative program and this may involve inhibiting the initiation of viral replication.
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19
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Interaction between NSMCE4A and GPS1 links the SMC5/6 complex to the COP9 signalosome. BMC Mol Cell Biol 2020; 21:36. [PMID: 32384871 PMCID: PMC7206739 DOI: 10.1186/s12860-020-00278-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 04/27/2020] [Indexed: 11/21/2022] Open
Abstract
Background The SMC5/6 complex, cohesin and condensin are the three mammalian members of the structural maintenance of chromosomes (SMC) family, large ring-like protein complexes that are essential for genome maintenance. The SMC5/6 complex is the least characterized complex in mammals; however, it is known to be involved in homologous recombination repair (HRR) and chromosome segregation. Results In this study, a yeast two-hybrid screen was used to help elucidate novel interactions of the kleisin subunit of the SMC5/6 complex, NSMCE4A. This approach discovered an interaction between NSMCE4A and GPS1, a COP9 signalosome (CSN) component, and this interaction was further confirmed by co-immunoprecipitation. Additionally, GPS1 and components of SMC5/6 complex colocalize during interphase and mitosis. CSN is a cullin deNEDDylase and is an important factor for HRR. Depletion of GPS1, which has been shown to negatively impact DNA end resection during HRR, caused an increase in SMC5/6 levels at sites of laser-induced DNA damage. Furthermore, inhibition of the dennedylation function of CSN increased SMC5/6 levels at sites of laser-induced DNA damage. Conclusion Taken together, these data demonstrate for the first time that the SMC5/6 and CSN complexes interact and provides evidence that the CSN complex influences SMC5/6 functions during cell cycle progression and response to DNA damage.
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20
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Venegas AB, Natsume T, Kanemaki M, Hickson ID. Inducible Degradation of the Human SMC5/6 Complex Reveals an Essential Role Only during Interphase. Cell Rep 2020; 31:107533. [DOI: 10.1016/j.celrep.2020.107533] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 02/11/2020] [Accepted: 03/27/2020] [Indexed: 12/19/2022] Open
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Abstract
Smc5 and Smc6, together with the kleisin Nse4, form the heart of the enigmatic and poorly understood Smc5/6 complex, which is frequently viewed as a cousin of cohesin and condensin with functions in DNA repair. As novel functions for cohesin and condensin complexes in the organization of long-range chromatin architecture have recently emerged, new unsuspected roles for Smc5/6 have also surfaced. Here, I aim to provide a comprehensive overview of our current knowledge of the Smc5/6 complex, including its long-established function in genome stability, its multiple roles in DNA repair, and its recently discovered connection to the transcription inhibition of hepatitis B virus genomes. In addition, I summarize new research that is beginning to tease out the molecular details of Smc5/6 structure and function, knowledge that will illuminate the nuclear activities of Smc5/6 in the stability and dynamics of eukaryotic genomes.
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Affiliation(s)
- Luis Aragón
- Cell Cycle Group, MRC London Institute of Medical Sciences, Hammersmith Hospital Campus, London W12 0NN, United Kingdom;
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22
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Zelkowski M, Zelkowska K, Conrad U, Hesse S, Lermontova I, Marzec M, Meister A, Houben A, Schubert V. Arabidopsis NSE4 Proteins Act in Somatic Nuclei and Meiosis to Ensure Plant Viability and Fertility. FRONTIERS IN PLANT SCIENCE 2019; 10:774. [PMID: 31281325 PMCID: PMC6596448 DOI: 10.3389/fpls.2019.00774] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/28/2019] [Indexed: 05/02/2023]
Abstract
The SMC 5/6 complex together with cohesin and condensin is a member of the structural maintenance of chromosome (SMC) protein family. In non-plant organisms SMC5/6 is engaged in DNA repair, meiotic synapsis, genome organization and stability. In plants, the function of SMC5/6 is still enigmatic. Therefore, we analyzed the crucial δ-kleisin component NSE4 of the SMC5/6 complex in the model plant Arabidopsis thaliana. Two functional conserved Nse4 paralogs (Nse4A and Nse4B) are present in A. thaliana, which may have evolved via gene subfunctionalization. Due to its high expression level, Nse4A seems to be the more essential gene, whereas Nse4B appears to be involved mainly in seed development. The morphological characterization of A. thaliana T-DNA mutants suggests that the NSE4 proteins are essential for plant growth and fertility. Detailed investigations in wild-type and the mutants based on live cell imaging of transgenic GFP lines, fluorescence in situ hybridization (FISH), immunolabeling and super-resolution microscopy suggest that NSE4A acts in several processes during plant development, such as mitosis, meiosis and chromatin organization of differentiated nuclei, and that NSE4A operates in a cell cycle-dependent manner. Differential response of NSE4A and NSE4B mutants after induced DNA double strand breaks (DSBs) suggests their involvement in DNA repair processes.
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Affiliation(s)
- Mateusz Zelkowski
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | - Katarzyna Zelkowska
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | - Udo Conrad
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | - Susann Hesse
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | - Inna Lermontova
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
- Plant Cytogenomics Research Group, Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Marek Marzec
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
- Department of Genetics, Faculty of Biology and Environmental Protection, University of Silesia, Katowice, Poland
| | - Armin Meister
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
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23
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Deiss K, Lockwood N, Howell M, Segeren HA, Saunders RE, Chakravarty P, Soliman TN, Martini S, Rocha N, Semple R, Zalmas LP, Parker PJ. A genome-wide RNAi screen identifies the SMC5/6 complex as a non-redundant regulator of a Topo2a-dependent G2 arrest. Nucleic Acids Res 2019; 47:2906-2921. [PMID: 30590722 PMCID: PMC6451093 DOI: 10.1093/nar/gky1295] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/12/2018] [Accepted: 12/17/2018] [Indexed: 01/08/2023] Open
Abstract
The Topo2a-dependent arrest is associated with faithful segregation of sister chromatids and has been identified as dysfunctional in numerous tumour cell lines. This genome-protecting pathway is poorly understood and its characterization is of significant interest, potentially offering interventional opportunities in relation to synthetic lethal behaviours in arrest-defective tumours. Using the catalytic Topo2a inhibitor ICRF193, we have performed a genome-wide siRNA screen in arrest-competent, non-transformed cells, to identify genes essential for this arrest mechanism. In addition, we have counter-screened several DNA-damaging agents and demonstrate that the Topo2a-dependent arrest is genetically distinct from DNA damage checkpoints. We identify the components of the SMC5/6 complex, including the activity of the E3 SUMO ligase NSE2, as non-redundant players that control the timing of the Topo2a-dependent arrest in G2. We have independently verified the NSE2 requirement in fibroblasts from patients with germline mutations that cause severely reduced levels of NSE2. Through imaging Topo2a-dependent G2 arrested cells, an increased interaction between Topo2a and NSE2 is observed at PML bodies, which are known SUMOylation hotspots. We demonstrate that Topo2a is SUMOylated in an ICRF193-dependent manner by NSE2 at a novel non-canonical site (K1520) and that K1520 sumoylation is required for chromosome segregation but not the G2 arrest.
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Affiliation(s)
- Katharina Deiss
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Nicola Lockwood
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Michael Howell
- High Throughput Screening, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Hendrika Alida Segeren
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Rebecca E Saunders
- High Throughput Screening, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Probir Chakravarty
- Bioinformatics, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Tanya N Soliman
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Silvia Martini
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Nuno Rocha
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge CB2 0QQ, UK
| | - Robert Semple
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge CB2 0QQ, UK
| | | | - Peter J Parker
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- School of Cancer and Pharmaceutical Sciences King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
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24
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Palecek JJ. SMC5/6: Multifunctional Player in Replication. Genes (Basel) 2018; 10:genes10010007. [PMID: 30583551 PMCID: PMC6356406 DOI: 10.3390/genes10010007] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 12/13/2022] Open
Abstract
The genome replication process is challenged at many levels. Replication must proceed through different problematic sites and obstacles, some of which can pause or even reverse the replication fork (RF). In addition, replication of DNA within chromosomes must deal with their topological constraints and spatial organization. One of the most important factors organizing DNA into higher-order structures are Structural Maintenance of Chromosome (SMC) complexes. In prokaryotes, SMC complexes ensure proper chromosomal partitioning during replication. In eukaryotes, cohesin and SMC5/6 complexes assist in replication. Interestingly, the SMC5/6 complexes seem to be involved in replication in many ways. They stabilize stalled RFs, restrain RF regression, participate in the restart of collapsed RFs, and buffer topological constraints during RF progression. In this (mini) review, I present an overview of these replication-related functions of SMC5/6.
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Affiliation(s)
- Jan J Palecek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic.
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25
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Hwang G, Verver DE, Handel MA, Hamer G, Jordan PW. Depletion of SMC5/6 sensitizes male germ cells to DNA damage. Mol Biol Cell 2018; 29:3003-3016. [PMID: 30281394 PMCID: PMC6333175 DOI: 10.1091/mbc.e18-07-0459] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The structural maintenance of chromosomes complex SMC5/6 is thought to be essential for DNA repair and chromosome segregation during mitosis and meiosis. To determine the requirements of the SMC5/6 complex during mouse spermatogenesis we combined a conditional knockout allele for Smc5, with four germ cell–specific Cre-recombinase transgenes, Ddx4-Cre, Stra8-Cre, Spo11-Cre, and Hspa2-Cre, to mutate Smc5 in spermatogonia, in spermatocytes before meiotic entry, during early meiotic stages, and during midmeiotic stages, respectively. Conditional mutation of Smc5 resulted in destabilization of the SMC5/6 complex. Despite this, we observed only mild defects in spermatogenesis. Mutation of Smc5 mediated by Ddx4-Cre and Stra8-Cre resulted in partial loss of preleptotene spermatocytes; however, spermatogenesis progresses and mice are fertile. Mutation of Smc5 via Spo11-Cre or Hspa2-Cre did not result in detectable defects of spermatogenesis. Upon exposure to gamma irradiation or etoposide treatment, each conditional Smc5 mutant demonstrated an increase in the number of enlarged round spermatids with multiple acrosomes and supernumerary chromosome content. We propose that the SMC5/6 complex is not acutely required for premeiotic DNA replication and meiotic progression during mouse spermatogenesis; however, when germ cells are challenged by exogenous DNA damage, the SMC5/6 complex ensures genome integrity, and thus, fertility.
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Affiliation(s)
- G Hwang
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205
| | - D E Verver
- Reproductive Biology Laboratory, Center for Reproductive Medicine, Academic Medical Center, 1105 AZ Amsterdam, the Netherlands
| | - M A Handel
- The Jackson Laboratory, Bar Harbor, ME 04609
| | - G Hamer
- Reproductive Biology Laboratory, Center for Reproductive Medicine, Academic Medical Center, 1105 AZ Amsterdam, the Netherlands
| | - P W Jordan
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205
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26
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Garcia J, Lizcano F. Kdm4c is Recruited to Mitotic Chromosomes and Is Relevant for Chromosomal Stability, Cell Migration and Invasion of Triple Negative Breast Cancer Cells. BREAST CANCER-BASIC AND CLINICAL RESEARCH 2018; 12:1178223418773075. [PMID: 30083054 PMCID: PMC6073829 DOI: 10.1177/1178223418773075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/04/2018] [Indexed: 01/23/2023]
Abstract
Members of the jumonji-containing lysine demethylase protein family have been associated with cancer development, although their specific roles in the evolution of tumor cells remain unknown. This work examines the effects of lysine demethylase 4C (KDM4C) knockdown on the behavior of a triple-negative breast cancer cell line. KDM4C expression was knocked-down by siRNA and analyzed by Western blot and immunofluorescence. HCC38 cell proliferation was examined by MTT assay, while breast cancer cells’ migration and invasion were tested in Transwell format by chemotaxis. Immunofluorescence assays showed that KDM4C, which is a key protein for modulating histone demethylation and chromosome stability through the distribution of genetic information, is located at the chromosomes during mitosis. Proliferation assays demonstrated that KDM4C is important for cell survival, while Transwell migration and invasion assays indicated that this protein is relevant for cancer progression. These data indicate that KDM4C is relevant for breast cancer progression and highlight its importance as a potential therapeutic target.
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Affiliation(s)
- Jeison Garcia
- Doctorate in Biociences, Center of Biomedical Research Universidad de La Sabana-CIBUS, School of Medicine, Universidad de La Sabana, Chía, Colombia
| | - Fernando Lizcano
- Doctorate in Biociences, Center of Biomedical Research Universidad de La Sabana-CIBUS, School of Medicine, Universidad de La Sabana, Chía, Colombia
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27
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Takahashi M, Hirota T. Dynamics of sister chromatids through the cell cycle: Together and apart. J Cell Biol 2018; 217:1887-1889. [PMID: 29764905 PMCID: PMC5987729 DOI: 10.1083/jcb.201804091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Takahashi and Hirota preview work from Stanyte et al. examining the behavior of sister chromatids and their resolution as the cell cycle progresses. When and how sister chromatid resolution occurs after DNA replication is a fundamental question. Stanyte et al. (2018. J. Cell Biol.https://doi.org/10.1083/jcb.201801157) used CRISPR/Cas9 technology to label and track genomic loci in live cells throughout the cell cycle, shedding light on how replication is linked to mitotic sister chromatid organization.
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Affiliation(s)
- Motoko Takahashi
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Toru Hirota
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan
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28
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DNA replication stress and its impact on chromosome segregation and tumorigenesis. Semin Cancer Biol 2018; 55:61-69. [PMID: 29692334 DOI: 10.1016/j.semcancer.2018.04.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 01/11/2023]
Abstract
Genome instability and cell cycle dysregulation are commonly associated with cancer. DNA replication stress driven by oncogene activation during tumorigenesis is now well established as a source of genome instability. Replication stress generates DNA damage not only during S phase, but also in the subsequent mitosis, where it impacts adversely on chromosome segregation. Some regions of the genome seem particularly sensitive to replication stress-induced instability; most notably, chromosome fragile sites. In this article, we review some of the important issues that have emerged in recent years concerning DNA replication stress and fragile site expression, as well as how chromosome instability is minimized by a family of ring-shaped protein complexes known as SMC proteins. Understanding how replication stress impacts on S phase and mitosis in cancer should provide opportunities for the development of novel and tumour-specific treatments.
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29
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Peng XP, Lim S, Li S, Marjavaara L, Chabes A, Zhao X. Acute Smc5/6 depletion reveals its primary role in rDNA replication by restraining recombination at fork pausing sites. PLoS Genet 2018; 14:e1007129. [PMID: 29360860 PMCID: PMC5779651 DOI: 10.1371/journal.pgen.1007129] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 11/27/2017] [Indexed: 11/18/2022] Open
Abstract
Smc5/6, a member of the conserved SMC family of complexes, is essential for growth in most organisms. Its exact functions in a mitotic cell cycle are controversial, as chronic Smc5/6 loss-of-function alleles produce varying phenotypes. To circumvent this issue, we acutely depleted Smc5/6 in budding yeast and determined the first cell cycle consequences of Smc5/6 removal. We found a striking primary defect in replication of the ribosomal DNA (rDNA) array. Each rDNA repeat contains a programmed replication fork barrier (RFB) established by the Fob1 protein. Fob1 removal improves rDNA replication in Smc5/6 depleted cells, implicating Smc5/6 in the management of programmed fork pausing. A similar improvement is achieved by removing the DNA helicase Mph1 whose recombinogenic activity can be inhibited by Smc5/6 under DNA damage conditions. DNA 2D gel analyses further show that Smc5/6 loss increases recombination structures at RFB regions; moreover, mph1∆ and fob1∆ similarly reduce this accumulation. These findings point to an important mitotic role for Smc5/6 in restraining recombination events when protein barriers in rDNA stall replication forks. As rDNA maintenance influences multiple essential cellular processes, Smc5/6 likely links rDNA stability to overall mitotic growth. Smc5/6 belongs to the SMC (Structural Maintenance of Chromosomes) family of protein complexes, all of which are highly conserved and critical for genome maintenance. To address the roles of Smc5/6 during growth, we rapidly depleted its subunits in yeast and found the main acute effect to be defective ribosomal DNA (rDNA) duplication. The rDNA contains hundreds of sites that can pause replication forks; these must be carefully managed for cells to finish replication. We found that reducing fork pausing improved rDNA replication in cells without Smc5/6. Further analysis suggested that Smc5/6 prevents the DNA helicase Mph1 from turning paused forks into recombination structures, which cannot be processed without Smc5/6. Our findings thus revealed a key role for Smc5/6 in managing endogenous replication fork pausing. As rDNA and its associated nucleolar structure are critical for overall genome maintenance and other cellular processes, rDNA regulation by Smc5/6 would be expected to have multilayered effects on cell physiology and growth.
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Affiliation(s)
- Xiao P. Peng
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
- Tri-Institutional MD-PhD Program of Weill Cornell Medical School, Rockefeller University, and Sloan-Kettering Cancer Center, New York, NY, United States of America
| | - Shelly Lim
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
| | - Shibai Li
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
| | - Lisette Marjavaara
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Andrei Chabes
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Xiaolan Zhao
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
- * E-mail:
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30
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Diaz M, Pecinka A. Scaffolding for Repair: Understanding Molecular Functions of the SMC5/6 Complex. Genes (Basel) 2018; 9:genes9010036. [PMID: 29329249 PMCID: PMC5793187 DOI: 10.3390/genes9010036] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/03/2018] [Accepted: 01/04/2018] [Indexed: 12/17/2022] Open
Abstract
Chromosome organization, dynamics and stability are required for successful passage through cellular generations and transmission of genetic information to offspring. The key components involved are Structural maintenance of chromosomes (SMC) complexes. Cohesin complex ensures proper chromatid alignment, condensin complex chromosome condensation and the SMC5/6 complex is specialized in the maintenance of genome stability. Here we summarize recent knowledge on the composition and molecular functions of SMC5/6 complex. SMC5/6 complex was originally identified based on the sensitivity of its mutants to genotoxic stress but there is increasing number of studies demonstrating its roles in the control of DNA replication, sister chromatid resolution and genomic location-dependent promotion or suppression of homologous recombination. Some of these functions appear to be due to a very dynamic interaction with cohesin or other repair complexes. Studies in Arabidopsis indicate that, besides its canonical function in repair of damaged DNA, the SMC5/6 complex plays important roles in regulating plant development, abiotic stress responses, suppression of autoimmune responses and sexual reproduction.
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Affiliation(s)
- Mariana Diaz
- Institute of Experimental Botany of the Czech Academy of Sciences (IEB), Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, 77900 Olomouc-Holice, Czech Republic.
- Max Planck Institute for Plant Breeding Research (MPIPZ), Carl-von-Linné-Weg 10, 50829 Cologne, Germany.
| | - Ales Pecinka
- Institute of Experimental Botany of the Czech Academy of Sciences (IEB), Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, 77900 Olomouc-Holice, Czech Republic.
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31
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Piskadlo E, Oliveira RA. A Topology-Centric View on Mitotic Chromosome Architecture. Int J Mol Sci 2017; 18:E2751. [PMID: 29258269 PMCID: PMC5751350 DOI: 10.3390/ijms18122751] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 02/04/2023] Open
Abstract
Mitotic chromosomes are long-known structures, but their internal organization and the exact process by which they are assembled are still a great mystery in biology. Topoisomerase II is crucial for various aspects of mitotic chromosome organization. The unique ability of this enzyme to untangle topologically intertwined DNA molecules (catenations) is of utmost importance for the resolution of sister chromatid intertwines. Although still controversial, topoisomerase II has also been proposed to directly contribute to chromosome compaction, possibly by promoting chromosome self-entanglements. These two functions raise a strong directionality issue towards topoisomerase II reactions that are able to disentangle sister DNA molecules (in trans) while compacting the same DNA molecule (in cis). Here, we review the current knowledge on topoisomerase II role specifically during mitosis, and the mechanisms that directly or indirectly regulate its activity to ensure faithful chromosome segregation. In particular, we discuss how the activity or directionality of this enzyme could be regulated by the SMC (structural maintenance of chromosomes) complexes, predominantly cohesin and condensin, throughout mitosis.
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Affiliation(s)
- Ewa Piskadlo
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
| | - Raquel A Oliveira
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
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32
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DNA Oncogenic Virus-Induced Oxidative Stress, Genomic Damage, and Aberrant Epigenetic Alterations. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:3179421. [PMID: 28740569 PMCID: PMC5504953 DOI: 10.1155/2017/3179421] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 05/01/2017] [Accepted: 05/23/2017] [Indexed: 12/18/2022]
Abstract
Approximately 20% of human cancers is attributable to DNA oncogenic viruses such as human papillomavirus (HPV), hepatitis B virus (HBV), and Epstein-Barr virus (EBV). Unrepaired DNA damage is the most common and overlapping feature of these DNA oncogenic viruses and a source of genomic instability and tumour development. Sustained DNA damage results from unceasing production of reactive oxygen species and activation of inflammasome cascades that trigger genomic changes and increased propensity of epigenetic alterations. Accumulation of epigenetic alterations may interfere with genome-wide cellular signalling machineries and promote malignant transformation leading to cancer development. Untangling and understanding the underlying mechanisms that promote these detrimental effects remain the major objectives for ongoing research and hope for effective virus-induced cancer therapy. Here, we review current literature with an emphasis on how DNA damage influences HPV, HVB, and EBV replication and epigenetic alterations that are associated with carcinogenesis.
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33
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Hwang G, Sun F, O'Brien M, Eppig JJ, Handel MA, Jordan PW. SMC5/6 is required for the formation of segregation-competent bivalent chromosomes during meiosis I in mouse oocytes. Development 2017; 144:1648-1660. [PMID: 28302748 PMCID: PMC5450844 DOI: 10.1242/dev.145607] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 03/07/2017] [Indexed: 01/11/2023]
Abstract
SMC complexes include three major classes: cohesin, condensin and SMC5/6. However, the localization pattern and genetic requirements for the SMC5/6 complex during mammalian oogenesis have not previously been examined. In mouse oocytes, the SMC5/6 complex is enriched at the pericentromeric heterochromatin, and also localizes along chromosome arms during meiosis. The infertility phenotypes of females with a Zp3-Cre-driven conditional knockout (cKO) of Smc5 demonstrated that maternally expressed SMC5 protein is essential for early embryogenesis. Interestingly, protein levels of SMC5/6 complex components in oocytes decline as wild-type females age. When SMC5/6 complexes were completely absent in oocytes during meiotic resumption, homologous chromosomes failed to segregate accurately during meiosis I. Despite what appears to be an inability to resolve concatenation between chromosomes during meiosis, localization of topoisomerase IIα to bivalents was not affected; however, localization of condensin along the chromosome axes was perturbed. Taken together, these data demonstrate that the SMC5/6 complex is essential for the formation of segregation-competent bivalents during meiosis I, and findings suggest that age-dependent depletion of the SMC5/6 complex in oocytes could contribute to increased incidence of oocyte aneuploidy and spontaneous abortion in aging females.
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Affiliation(s)
- Grace Hwang
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Fengyun Sun
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | | | - John J Eppig
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | | | - Philip W Jordan
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
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34
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Identifying and Characterizing Interplay between Hepatitis B Virus X Protein and Smc5/6. Viruses 2017; 9:v9040069. [PMID: 28368357 PMCID: PMC5408675 DOI: 10.3390/v9040069] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/27/2017] [Accepted: 03/29/2017] [Indexed: 12/17/2022] Open
Abstract
Hepatitis B X protein (HBx) plays an essential role in the hepatitis B virus (HBV) replication cycle, but the function of HBx has been elusive until recently. It was recently shown that transcription from the HBV genome (covalently-closed circular DNA, cccDNA) is inhibited by the structural maintenance of chromosome 5/6 complex (Smc5/6), and that a key function of HBx is to redirect the DNA-damage binding protein 1 (DDB1) E3 ubiquitin ligase to target this complex for degradation. By doing so, HBx alleviates transcriptional repression by Smc5/6 and stimulates HBV gene expression. In this review, we discuss in detail how the interplay between HBx and Smc5/6 was identified and characterized. We also discuss what is known regarding the repression of cccDNA transcription by Smc5/6, the timing of HBx expression, and the potential role of HBx in promoting hepatocellular carcinoma (HCC).
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35
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Li G, Zou W, Jian L, Qian J, Deng Y, Zhao J. Non-SMC elements 1 and 3 are required for early embryo and seedling development in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:1039-1054. [PMID: 28207059 PMCID: PMC5441860 DOI: 10.1093/jxb/erx016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Early embryo development from the zygote is an essential stage in the formation of the seed, while seedling development is the beginning of the formation of an individual plant. AtNSE1 and AtNSE3 are subunits of the structural maintenance of chromosomes (SMC) 5/6 complex and have been identified as non-SMC elements, but their functions in Arabidopsis growth and development remain as yet unknown. In this study, we found that loss of function of AtNSE1 and AtNSE3 led to severe defects in early embryo development. Partially complemented mutants showed that the development of mutant seedlings was inhibited, that chromosome fragments occurred during anaphase, and that the cell cycle was delayed at G2/M, which led to the occurrence of endoreduplication. Further, a large number of DNA double-strand breaks (DSBs) occurred in the nse1 and nse3 mutants, and the expression of AtNSE1 and AtNSE3 was up-regulated following treatment of the plants with DSB inducer compounds, suggesting that AtNSE1 and AtNSE3 have a role in DNA damage repair. Therefore, we conclude that AtNSE1 and AtNSE3 facilitate DSB repair and contribute to maintaining genome stability and cell division in mitotic cells. Thus, we think that AtNSE1 and AtNSE3 may be crucial factors for maintaining proper early embryonic and post-embryonic development.
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Affiliation(s)
- Gang Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Wenxuan Zou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Liufang Jian
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jie Qian
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yingtian Deng
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
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36
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Niu C, Livingston CM, Li L, Beran RK, Daffis S, Ramakrishnan D, Burdette D, Peiser L, Salas E, Ramos H, Yu M, Cheng G, Strubin M, Delaney IV WE, Fletcher SP. The Smc5/6 Complex Restricts HBV when Localized to ND10 without Inducing an Innate Immune Response and Is Counteracted by the HBV X Protein Shortly after Infection. PLoS One 2017; 12:e0169648. [PMID: 28095508 PMCID: PMC5240991 DOI: 10.1371/journal.pone.0169648] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 12/20/2016] [Indexed: 02/06/2023] Open
Abstract
The structural maintenance of chromosome 5/6 complex (Smc5/6) is a restriction factor that represses hepatitis B virus (HBV) transcription. HBV counters this restriction by expressing HBV X protein (HBx), which targets Smc5/6 for degradation. However, the mechanism by which Smc5/6 suppresses HBV transcription and how HBx is initially expressed is not known. In this study we characterized viral kinetics and the host response during HBV infection of primary human hepatocytes (PHH) to address these unresolved questions. We determined that Smc5/6 localizes with Nuclear Domain 10 (ND10) in PHH. Co-localization has functional implications since depletion of ND10 structural components alters the nuclear distribution of Smc6 and induces HBV gene expression in the absence of HBx. We also found that HBV infection and replication does not induce a prominent global host transcriptional response in PHH, either shortly after infection when Smc5/6 is present, or at later times post-infection when Smc5/6 has been degraded. Notably, HBV and an HBx-negative virus establish high level infection in PHH without inducing expression of interferon-stimulated genes or production of interferons or other cytokines. Our study also revealed that Smc5/6 is degraded in the majority of infected PHH by the time cccDNA transcription could be detected and that HBx RNA is present in cell culture-derived virus preparations as well as HBV patient plasma. Collectively, these data indicate that Smc5/6 is an intrinsic antiviral restriction factor that suppresses HBV transcription when localized to ND10 without inducing a detectable innate immune response. Our data also suggest that HBx protein may be initially expressed by delivery of extracellular HBx RNA into HBV-infected cells.
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Affiliation(s)
- Congrong Niu
- Gilead Sciences, Foster City, California, United States of America
| | | | - Li Li
- Gilead Sciences, Foster City, California, United States of America
| | - Rudolf K. Beran
- Gilead Sciences, Foster City, California, United States of America
| | - Stephane Daffis
- Gilead Sciences, Foster City, California, United States of America
| | | | - Dara Burdette
- Gilead Sciences, Foster City, California, United States of America
| | - Leanne Peiser
- Gilead Sciences, Foster City, California, United States of America
| | - Eduardo Salas
- Gilead Sciences, Foster City, California, United States of America
| | - Hilario Ramos
- Gilead Sciences, Foster City, California, United States of America
| | - Mei Yu
- Gilead Sciences, Foster City, California, United States of America
| | - Guofeng Cheng
- Gilead Sciences, Foster City, California, United States of America
| | - Michel Strubin
- Department of Microbiology and Molecular Medicine, University Medical Center (C.M.U.), Geneva, Switzerland
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37
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Garcia J, Lizcano F. KDM4C Activity Modulates Cell Proliferation and Chromosome Segregation in Triple-Negative Breast Cancer. BREAST CANCER-BASIC AND CLINICAL RESEARCH 2016; 10:169-175. [PMID: 27840577 PMCID: PMC5094578 DOI: 10.4137/bcbcr.s40182] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/14/2016] [Accepted: 08/20/2016] [Indexed: 12/23/2022]
Abstract
The Jumonji-containing domain protein, KDM4C, is a histone demethylase associated with the development of several forms of human cancer. However, its specific function in the viability of tumoral lineages is yet to be determined. This work investigates the importance of KDM4C activity in cell proliferation and chromosome segregation of three triple-negative breast cancer cell lines using a specific demethylase inhibitor. Immunofluorescence assays show that KDM4C is recruited to mitotic chromosomes and that the modulation of its activity increases the number of mitotic segregation errors. However, 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) cell proliferation assays demonstrate that the demethylase activity is required for cell viability. These results suggest that the histone demethylase activity of KDM4C is essential for breast cancer progression given its role in the maintenance of chromosomal stability and cell growth, thus highlighting it as a potential therapeutic target.
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Affiliation(s)
- Jeison Garcia
- Doctorate in Biosciences, Center of Biomedical Research Universidad de La Sabana-CIBUS, School of Medicine, Universidad de La Sabana, Chía, Colombia
| | - Fernando Lizcano
- Doctorate in Biosciences, Center of Biomedical Research Universidad de La Sabana-CIBUS, School of Medicine, Universidad de La Sabana, Chía, Colombia
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Kratz AS, Richter KT, Schlosser YT, Schmitt M, Shumilov A, Delecluse HJ, Hoffmann I. Fbxo28 promotes mitotic progression and regulates topoisomerase IIα-dependent DNA decatenation. Cell Cycle 2016; 15:3419-3431. [PMID: 27754753 DOI: 10.1080/15384101.2016.1246093] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Topoisomerase IIα is an essential enzyme that resolves topological constraints in genomic DNA. It functions in disentangling intertwined chromosomes during anaphase leading to chromosome segregation thus preserving genomic stability. Here we describe a previously unrecognized mechanism regulating topoisomerase IIα activity that is dependent on the F-box protein Fbxo28. We find that Fbxo28, an evolutionarily conserved protein, is required for proper mitotic progression. Interfering with Fbxo28 function leads to a delay in metaphase-to-anaphase progression resulting in mitotic defects as lagging chromosomes, multipolar spindles and multinucleation. Furthermore, we find that Fbxo28 interacts and colocalizes with topoisomerase IIα throughout the cell cycle. Depletion of Fbxo28 results in an increase in topoisomerase IIα-dependent DNA decatenation activity. Interestingly, blocking the interaction between Fbxo28 and topoisomerase IIα also results in multinucleated cells. Our findings suggest that Fbxo28 regulates topoisomerase IIα decatenation activity and plays an important role in maintaining genomic stability.
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Affiliation(s)
- Anne-Sophie Kratz
- a Cell Cycle Control and Carcinogenesis, F045, German Cancer Research Center , Heidelberg , Germany
| | - Kai T Richter
- a Cell Cycle Control and Carcinogenesis, F045, German Cancer Research Center , Heidelberg , Germany
| | - Yvonne T Schlosser
- a Cell Cycle Control and Carcinogenesis, F045, German Cancer Research Center , Heidelberg , Germany
| | - Miriam Schmitt
- a Cell Cycle Control and Carcinogenesis, F045, German Cancer Research Center , Heidelberg , Germany
| | - Anatoliy Shumilov
- b Pathogenesis of Virus Associated Tumors, F100, German Cancer Research Center , Heidelberg , Germany
| | - Henri-Jacques Delecluse
- b Pathogenesis of Virus Associated Tumors, F100, German Cancer Research Center , Heidelberg , Germany
| | - Ingrid Hoffmann
- a Cell Cycle Control and Carcinogenesis, F045, German Cancer Research Center , Heidelberg , Germany
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39
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Gligoris T, Löwe J. Structural Insights into Ring Formation of Cohesin and Related Smc Complexes. Trends Cell Biol 2016; 26:680-693. [PMID: 27134029 PMCID: PMC4989898 DOI: 10.1016/j.tcb.2016.04.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/30/2016] [Accepted: 04/05/2016] [Indexed: 12/14/2022]
Abstract
Cohesin facilitates sister chromatid cohesion through the formation of a large ring structure that encircles DNA. Its function relies on two structural maintenance of chromosomes (Smc) proteins, which are found in almost all organisms tested, from bacteria to humans. In accordance with their ubiquity, Smc complexes, such as cohesin, condensin, Smc5-6, and the dosage compensation complex, affect almost all processes of DNA homeostasis. Although their precise molecular mechanism remains enigmatic, here we provide an overview of the architecture of eukaryotic Smc complexes with a particular focus on cohesin, which has seen the most progress recently. Given the evident conservation of many structural features between Smc complexes, it is expected that architecture and topology will have a significant role when deciphering their precise molecular mechanisms.
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Affiliation(s)
- Thomas Gligoris
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
| | - Jan Löwe
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
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40
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Peng J, Feng W. Incision of damaged DNA in the presence of an impaired Smc5/6 complex imperils genome stability. Nucleic Acids Res 2016; 44:10216-10229. [PMID: 27536003 PMCID: PMC5137426 DOI: 10.1093/nar/gkw720] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 11/14/2022] Open
Abstract
The Smc5/6 complex is implicated in homologous recombination-mediated DNA repair during DNA damage or replication stress. Here, we analysed genome-wide replication dynamics in a hypomorphic budding yeast mutant, smc6-P4. The overall replication dynamics in the smc6 mutant is similar to that in the wild-type cells. However, we captured a difference in the replication profile of an early S phase sample in the mutant, prompting the hypothesis that the mutant incorporates ribonucleotides and/or accumulates single-stranded DNA gaps during replication. We tested if inhibiting the ribonucleotide excision repair pathway would exacerbate the smc6 mutant in response to DNA replication stress. Contrary to our expectation, impairment of ribonucleotide excision repair, as well as virtually all other DNA repair pathways, alleviated smc6 mutant's hypersensitivity to induced replication stress. We propose that nucleotide incision in the absence of a functional Smc5/6 complex has more disastrous outcomes than the damage per se. Our study provides novel perspectives for the role of the Smc5/6 complex during DNA replication.
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Affiliation(s)
- Jie Peng
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
| | - Wenyi Feng
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
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41
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Ohta S, Montaño-Gutierrez LF, de Lima Alves F, Ogawa H, Toramoto I, Sato N, Morrison CG, Takeda S, Hudson DF, Rappsilber J, Earnshaw WC. Proteomics Analysis with a Nano Random Forest Approach Reveals Novel Functional Interactions Regulated by SMC Complexes on Mitotic Chromosomes. Mol Cell Proteomics 2016; 15:2802-18. [PMID: 27231315 PMCID: PMC4974353 DOI: 10.1074/mcp.m116.057885] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 05/04/2016] [Indexed: 12/31/2022] Open
Abstract
Packaging of DNA into condensed chromosomes during mitosis is essential for the faithful segregation of the genome into daughter nuclei. Although the structure and composition of mitotic chromosomes have been studied for over 30 years, these aspects are yet to be fully elucidated. Here, we used stable isotope labeling with amino acids in cell culture to compare the proteomes of mitotic chromosomes isolated from cell lines harboring conditional knockouts of members of the condensin (SMC2, CAP-H, CAP-D3), cohesin (Scc1/Rad21), and SMC5/6 (SMC5) complexes. Our analysis revealed that these complexes associate with chromosomes independently of each other, with the SMC5/6 complex showing no significant dependence on any other chromosomal proteins during mitosis. To identify subtle relationships between chromosomal proteins, we employed a nano Random Forest (nanoRF) approach to detect protein complexes and the relationships between them. Our nanoRF results suggested that as few as 113 of 5058 detected chromosomal proteins are functionally linked to chromosome structure and segregation. Furthermore, nanoRF data revealed 23 proteins that were not previously suspected to have functional interactions with complexes playing important roles in mitosis. Subsequent small-interfering-RNA-based validation and localization tracking by green fluorescent protein-tagging highlighted novel candidates that might play significant roles in mitotic progression.
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Affiliation(s)
- Shinya Ohta
- From the ‡Center for Innovative and Translational Medicine, Medical School, Kochi University Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan; §Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3BF, UK;
| | - Luis F Montaño-Gutierrez
- §Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3BF, UK
| | - Flavia de Lima Alves
- §Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3BF, UK
| | - Hiromi Ogawa
- §Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3BF, UK
| | - Iyo Toramoto
- From the ‡Center for Innovative and Translational Medicine, Medical School, Kochi University Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan
| | - Nobuko Sato
- From the ‡Center for Innovative and Translational Medicine, Medical School, Kochi University Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan
| | - Ciaran G Morrison
- ¶Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Shunichi Takeda
- ‖Department of Radiation Genetics, Kyoto University Graduate School of Medicine, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan
| | - Damien F Hudson
- **Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, Victoria 3052, Australia
| | - Juri Rappsilber
- §Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3BF, UK; ‡‡Chair of Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - William C Earnshaw
- §Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3BF, UK
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Abstract
Heterochromatin is the transcriptionally repressed portion of eukaryotic chromatin that maintains a condensed appearance throughout the cell cycle. At sites of ribosomal DNA (rDNA) heterochromatin, epigenetic states contribute to gene silencing and genome stability, which are required for proper chromosome segregation and a normal life span. Here, we focus on recent advances in the epigenetic regulation of rDNA silencing in Saccharomyces cerevisiae and in mammals, including regulation by several histone modifications and several protein components associated with the inner nuclear membrane within the nucleolus. Finally, we discuss the perturbations of rDNA epigenetic pathways in regulating cellular aging and in causing various types of diseases.
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Pryzhkova MV, Jordan PW. Conditional mutation of Smc5 in mouse embryonic stem cells perturbs condensin localization and mitotic progression. J Cell Sci 2016; 129:1619-34. [PMID: 26919979 PMCID: PMC4852767 DOI: 10.1242/jcs.179036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 02/22/2016] [Indexed: 12/11/2022] Open
Abstract
Correct duplication of stem cell genetic material and its appropriate segregation into daughter cells are requisites for tissue, organ and organism homeostasis. Disruption of stem cell genomic integrity can lead to developmental abnormalities and cancer. Roles of the Smc5/6 structural maintenance of chromosomes complex in pluripotent stem cell genome maintenance have not been investigated, despite its important roles in DNA synthesis, DNA repair and chromosome segregation as evaluated in other model systems. Using mouse embryonic stem cells (mESCs) with a conditional knockout allele of Smc5, we showed that Smc5 protein depletion resulted in destabilization of the Smc5/6 complex, accumulation of cells in G2 phase of the cell cycle and apoptosis. Detailed assessment of mitotic mESCs revealed abnormal condensin distribution and perturbed chromosome segregation, accompanied by irregular spindle morphology, lagging chromosomes and DNA bridges. Mutation of Smc5 resulted in retention of Aurora B kinase and enrichment of condensin on chromosome arms. Furthermore, we observed reduced levels of Polo-like kinase 1 at kinetochores during mitosis. Our study reveals crucial requirements of the Smc5/6 complex during cell cycle progression and for stem cell genome maintenance.
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Affiliation(s)
- Marina V Pryzhkova
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Philip W Jordan
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
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44
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Condensin I and II behaviour in interphase nuclei and cells undergoing premature chromosome condensation. Chromosome Res 2016; 24:243-69. [PMID: 27008552 DOI: 10.1007/s10577-016-9519-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/07/2016] [Indexed: 10/22/2022]
Abstract
Condensin is an integral component of the mitotic chromosome condensation machinery, which ensures orderly segregation of chromosomes during cell division. In metazoans, condensin exists as two complexes, condensin I and II. It is not yet clear what roles these complexes may play outside mitosis, and so we have examined their behaviour both in normal interphase and in premature chromosome condensation (PCC). We find that a small fraction of condensin I is retained in interphase nuclei, and our data suggests that this interphase nuclear condensin I is active in both gene regulation and chromosome condensation. Furthermore, live cell imaging demonstrates condensin II dramatically increases on G1 nuclei following completion of mitosis. Our PCC studies show condensins I and II and topoisomerase II localise to the chromosome axis in G1-PCC and G2/M-PCC, while KIF4 binding is altered. Individually, condensins I and II are dispensable for PCC. However, when both are knocked out, G1-PCC chromatids are less well structured. Our results define new roles for the condensins during interphase and provide new information about the mechanism of PCC.
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45
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Hong Y, Sonneville R, Agostinho A, Meier B, Wang B, Blow JJ, Gartner A. The SMC-5/6 Complex and the HIM-6 (BLM) Helicase Synergistically Promote Meiotic Recombination Intermediate Processing and Chromosome Maturation during Caenorhabditis elegans Meiosis. PLoS Genet 2016; 12:e1005872. [PMID: 27010650 PMCID: PMC4807058 DOI: 10.1371/journal.pgen.1005872] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 01/25/2016] [Indexed: 11/19/2022] Open
Abstract
Meiotic recombination is essential for the repair of programmed double strand breaks (DSBs) to generate crossovers (COs) during meiosis. The efficient processing of meiotic recombination intermediates not only needs various resolvases but also requires proper meiotic chromosome structure. The Smc5/6 complex belongs to the structural maintenance of chromosome (SMC) family and is closely related to cohesin and condensin. Although the Smc5/6 complex has been implicated in the processing of recombination intermediates during meiosis, it is not known how Smc5/6 controls meiotic DSB repair. Here, using Caenorhabditis elegans we show that the SMC-5/6 complex acts synergistically with HIM-6, an ortholog of the human Bloom syndrome helicase (BLM) during meiotic recombination. The concerted action of the SMC-5/6 complex and HIM-6 is important for processing recombination intermediates, CO regulation and bivalent maturation. Careful examination of meiotic chromosomal morphology reveals an accumulation of inter-chromosomal bridges in smc-5; him-6 double mutants, leading to compromised chromosome segregation during meiotic cell divisions. Interestingly, we found that the lethality of smc-5; him-6 can be rescued by loss of the conserved BRCA1 ortholog BRC-1. Furthermore, the combined deletion of smc-5 and him-6 leads to an irregular distribution of condensin and to chromosome decondensation defects reminiscent of condensin depletion. Lethality conferred by condensin depletion can also be rescued by BRC-1 depletion. Our results suggest that SMC-5/6 and HIM-6 can synergistically regulate recombination intermediate metabolism and suppress ectopic recombination by controlling chromosome architecture during meiosis.
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Affiliation(s)
- Ye Hong
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - Remi Sonneville
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - Ana Agostinho
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - Bettina Meier
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - Bin Wang
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - J. Julian Blow
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - Anton Gartner
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
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46
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Zabrady K, Adamus M, Vondrova L, Liao C, Skoupilova H, Novakova M, Jurcisinova L, Alt A, Oliver AW, Lehmann AR, Palecek JJ. Chromatin association of the SMC5/6 complex is dependent on binding of its NSE3 subunit to DNA. Nucleic Acids Res 2016; 44:1064-79. [PMID: 26446992 PMCID: PMC4756808 DOI: 10.1093/nar/gkv1021] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 09/23/2015] [Accepted: 09/26/2015] [Indexed: 11/13/2022] Open
Abstract
SMC5/6 is a highly conserved protein complex related to cohesin and condensin, which are the key components of higher-order chromatin structures. The SMC5/6 complex is essential for proliferation in yeast and is involved in replication fork stability and processing. However, the precise mechanism of action of SMC5/6 is not known. Here we present evidence that the NSE1/NSE3/NSE4 sub-complex of SMC5/6 binds to double-stranded DNA without any preference for DNA-replication/recombination intermediates. Mutations of key basic residues within the NSE1/NSE3/NSE4 DNA-binding surface reduce binding to DNA in vitro. Their introduction into the Schizosaccharomyces pombe genome results in cell death or hypersensitivity to DNA damaging agents. Chromatin immunoprecipitation analysis of the hypomorphic nse3 DNA-binding mutant shows a reduced association of fission yeast SMC5/6 with chromatin. Based on our results, we propose a model for loading of the SMC5/6 complex onto the chromatin.
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Affiliation(s)
- Katerina Zabrady
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, Brno, 62500, Czech Republic Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, Brno, 61137, Czech Republic
| | - Marek Adamus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, Brno, 62500, Czech Republic
| | - Lucie Vondrova
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, Brno, 62500, Czech Republic Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, Brno, 61137, Czech Republic
| | - Chunyan Liao
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, United Kingdom
| | - Hana Skoupilova
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, Brno, 61137, Czech Republic
| | - Marketa Novakova
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, Brno, 61137, Czech Republic
| | - Lenka Jurcisinova
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, Brno, 62500, Czech Republic Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, Brno, 61137, Czech Republic
| | - Aaron Alt
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, United Kingdom
| | - Antony W Oliver
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, United Kingdom
| | - Alan R Lehmann
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, United Kingdom
| | - Jan J Palecek
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, Brno, 62500, Czech Republic Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, Brno, 61137, Czech Republic
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47
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Palecek JJ, Gruber S. Kite Proteins: a Superfamily of SMC/Kleisin Partners Conserved Across Bacteria, Archaea, and Eukaryotes. Structure 2015; 23:2183-2190. [DOI: 10.1016/j.str.2015.10.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/23/2015] [Accepted: 10/01/2015] [Indexed: 10/22/2022]
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48
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Jacome A, Gutierrez-Martinez P, Schiavoni F, Tenaglia E, Martinez P, Rodríguez-Acebes S, Lecona E, Murga M, Méndez J, Blasco MA, Fernandez-Capetillo O. NSMCE2 suppresses cancer and aging in mice independently of its SUMO ligase activity. EMBO J 2015; 34:2604-19. [PMID: 26443207 DOI: 10.15252/embj.201591829] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 09/01/2015] [Indexed: 01/16/2023] Open
Abstract
The SMC5/6 complex is the least understood of SMC complexes. In yeast, smc5/6 mutants phenocopy mutations in sgs1, the BLM ortholog that is deficient in Bloom's syndrome (BS). We here show that NSMCE2 (Mms21, in Saccharomyces cerevisiae), an essential SUMO ligase of the SMC5/6 complex, suppresses cancer and aging in mice. Surprisingly, a mutation that compromises NSMCE2-dependent SUMOylation does not have a detectable impact on murine lifespan. In contrast, NSMCE2 deletion in adult mice leads to pathologies resembling those found in patients of BS. Moreover, and whereas NSMCE2 deletion does not have a detectable impact on DNA replication, NSMCE2-deficient cells also present the cellular hallmarks of BS such as increased recombination rates and an accumulation of micronuclei. Despite the similarities, NSMCE2 and BLM foci do not colocalize and concomitant deletion of Blm and Nsmce2 in B lymphocytes further increases recombination rates and is synthetic lethal due to severe chromosome mis-segregation. Our work reveals that SUMO- and BLM-independent activities of NSMCE2 limit recombination and facilitate segregation; functions of the SMC5/6 complex that are necessary to prevent cancer and aging in mice.
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Affiliation(s)
- Ariana Jacome
- Genomic Instability Group, Spanish National Cancer Research Centre, Madrid, Spain
| | | | - Federica Schiavoni
- Genomic Instability Group, Spanish National Cancer Research Centre, Madrid, Spain
| | - Enrico Tenaglia
- Genomic Instability Group, Spanish National Cancer Research Centre, Madrid, Spain
| | - Paula Martinez
- Telomeres and Telomerase Group, Spanish National Cancer Research Centre, Madrid, Spain
| | | | - Emilio Lecona
- Genomic Instability Group, Spanish National Cancer Research Centre, Madrid, Spain
| | - Matilde Murga
- Genomic Instability Group, Spanish National Cancer Research Centre, Madrid, Spain
| | - Juan Méndez
- DNA Replication Group, Spanish National Cancer Research Centre, Madrid, Spain
| | - Maria A Blasco
- Telomeres and Telomerase Group, Spanish National Cancer Research Centre, Madrid, Spain
| | - Oscar Fernandez-Capetillo
- Genomic Instability Group, Spanish National Cancer Research Centre, Madrid, Spain Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
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49
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The Smc5/6 Complex Is an ATP-Dependent Intermolecular DNA Linker. Cell Rep 2015; 12:1471-82. [PMID: 26299966 DOI: 10.1016/j.celrep.2015.07.048] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 06/30/2015] [Accepted: 07/23/2015] [Indexed: 12/13/2022] Open
Abstract
The structural maintenance of chromosome (SMC) protein complexes cohesin and condensin and the Smc5/6 complex (Smc5/6) are crucial for chromosome dynamics and stability. All contain essential ATPase domains, and cohesin and condensin interact with chromosomes through topological entrapment of DNA. However, how Smc5/6 binds DNA and chromosomes has remained largely unknown. Here, we show that purified Smc5/6 binds DNA through a mechanism that requires ATP hydrolysis by the complex and circular DNA to be established. This also promotes topoisomerase 2-dependent catenation of plasmids, suggesting that Smc5/6 interconnects two DNA molecules using ATP-regulated topological entrapment of DNA, similar to cohesin. We also show that a complex containing an Smc6 mutant that is defective in ATP binding fails to interact with DNA and chromosomes and leads to cell death with concomitant accumulation of DNA damage when overexpressed. Taken together, these results indicate that Smc5/6 executes its cellular functions through ATP-regulated intermolecular DNA linking.
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50
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Roy MA, Dhanaraman T, D'Amours D. The Smc5-Smc6 heterodimer associates with DNA through several independent binding domains. Sci Rep 2015; 5:9797. [PMID: 25984708 PMCID: PMC4434891 DOI: 10.1038/srep09797] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 03/20/2015] [Indexed: 12/12/2022] Open
Abstract
The Smc5-6 complex is required for the maintenance of genome integrity through its
functions in DNA repair and chromosome biogenesis. However, the specific mode of
action of Smc5 and Smc6 in these processes remains largely unknown. We previously
showed that individual components of the Smc5-Smc6 complex bind strongly to DNA as
monomers, despite the absence of a canonical DNA-binding domain (DBD) in these
proteins. How heterodimerization of Smc5-6 affects its binding to DNA, and which
parts of the SMC molecules confer DNA-binding activity is not known at present. To
address this knowledge gap, we characterized the functional domains of the Smc5-6
heterodimer and identify two DBDs in each SMC molecule. The first DBD is located
within the SMC hinge region and its adjacent coiled-coil arms, while the second is
found in the conserved ATPase head domain. These DBDs can independently recapitulate
the substrate preference of the full-length Smc5 and Smc6 proteins. We also show
that heterodimerization of full-length proteins specifically increases the affinity
of the resulting complex for double-stranded DNA substrates. Collectively, our
findings provide critical insights into the structural requirements for effective
binding of the Smc5-6 complex to DNA repair substrates in vitro and in live
cells.
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Affiliation(s)
- Marc-André Roy
- Institute for Research in Immunology and Cancer, and Département de Pathologie et biologie cellulaire, Université de Montréal P.O. Box 6128, Succursale Centre-Ville Montréal, QC, H3C 3J7, Canada
| | - Thillaivillalan Dhanaraman
- Institute for Research in Immunology and Cancer, and Département de Pathologie et biologie cellulaire, Université de Montréal P.O. Box 6128, Succursale Centre-Ville Montréal, QC, H3C 3J7, Canada
| | - Damien D'Amours
- Institute for Research in Immunology and Cancer, and Département de Pathologie et biologie cellulaire, Université de Montréal P.O. Box 6128, Succursale Centre-Ville Montréal, QC, H3C 3J7, Canada
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