1
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Huq E, Lin C, Quail PH. Light signaling in plants-a selective history. PLANT PHYSIOLOGY 2024; 195:213-231. [PMID: 38431282 PMCID: PMC11060691 DOI: 10.1093/plphys/kiae110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/15/2023] [Accepted: 02/16/2024] [Indexed: 03/05/2024]
Abstract
In addition to providing the radiant energy that drives photosynthesis, sunlight carries signals that enable plants to grow, develop and adapt optimally to the prevailing environment. Here we trace the path of research that has led to our current understanding of the cellular and molecular mechanisms underlying the plant's capacity to perceive and transduce these signals into appropriate growth and developmental responses. Because a fully comprehensive review was not possible, we have restricted our coverage to the phytochrome and cryptochrome classes of photosensory receptors, while recognizing that the phototropin and UV classes also contribute importantly to the full scope of light-signal monitoring by the plant.
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Affiliation(s)
- Enamul Huq
- Department of Molecular Biosciences and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Chentao Lin
- Basic Forestry and Plant Proteomics Research Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Peter H Quail
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Plant Gene Expression Center, Agricultural Research Service, US Department of Agriculture, Albany, CA 94710, USA
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2
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Abstract
Many cellular processes require large-scale rearrangements of chromatin structure. Structural maintenance of chromosomes (SMC) protein complexes are molecular machines that can provide structure to chromatin. These complexes can connect DNA elements in cis, walk along DNA, build and processively enlarge DNA loops and connect DNA molecules in trans to hold together the sister chromatids. These DNA-shaping abilities place SMC complexes at the heart of many DNA-based processes, including chromosome segregation in mitosis, transcription control and DNA replication, repair and recombination. In this Review, we discuss the latest insights into how SMC complexes such as cohesin, condensin and the SMC5-SMC6 complex shape DNA to direct these fundamental chromosomal processes. We also consider how SMC complexes, by building chromatin loops, can counteract the natural tendency of alike chromatin regions to cluster. SMC complexes thus control nuclear organization by participating in a molecular tug of war that determines the architecture of our genome.
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Affiliation(s)
- Claire Hoencamp
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Benjamin D Rowland
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
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3
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Guo T, Liu M, Chen L, Liu Y, Li L, Li Y, Cao X, Mao Z, Wang W, Yang HQ. Photoexcited cryptochromes interact with ADA2b and SMC5 to promote the repair of DNA double-strand breaks in Arabidopsis. NATURE PLANTS 2023; 9:1280-1290. [PMID: 37488265 DOI: 10.1038/s41477-023-01461-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/20/2023] [Indexed: 07/26/2023]
Abstract
Cryptochromes (CRYs) act as blue-light photoreceptors that regulate development and circadian rhythms in plants and animals and as navigating magnetoreceptors in migratory birds. DNA double-strand breaks (DSBs) are the most serious type of DNA damage and threaten genome stability in all organisms. Although CRYs have been shown to respond to DNA damage, whether and how they participate in DSB repair is not well understood. Here we report that Arabidopsis CRYs promote the repair of DSBs through direct interactions with ADA2b and SMC5 in a blue-light-dependent manner to enhance their interaction. Mutations in CRYs and in ADA2b lead to similar enhanced DNA damage accumulation. In response to DNA damage, CRYs are localized at DSBs, and the recruitment of SMC5 to DSBs is dependent on CRYs. These results suggest that CRY-enhanced ADA2b-SMC5 interaction promotes ADA2b-mediated recruitment of SMC5 to DSBs, leading to DSB repair.
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Affiliation(s)
- Tongtong Guo
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Minqing Liu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Li Chen
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Yao Liu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Ling Li
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Yupeng Li
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Xiaoli Cao
- School of Life Sciences, Fudan University, Shanghai, China
| | - Zhilei Mao
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Wenxiu Wang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Hong-Quan Yang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China.
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4
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Pradhan B, Kanno T, Umeda Igarashi M, Loke MS, Baaske MD, Wong JSK, Jeppsson K, Björkegren C, Kim E. The Smc5/6 complex is a DNA loop-extruding motor. Nature 2023; 616:843-848. [PMID: 37076626 PMCID: PMC10132971 DOI: 10.1038/s41586-023-05963-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 03/16/2023] [Indexed: 04/21/2023]
Abstract
Structural maintenance of chromosomes (SMC) protein complexes are essential for the spatial organization of chromosomes1. Whereas cohesin and condensin organize chromosomes by extrusion of DNA loops, the molecular functions of the third eukaryotic SMC complex, Smc5/6, remain largely unknown2. Using single-molecule imaging, we show that Smc5/6 forms DNA loops by extrusion. Upon ATP hydrolysis, Smc5/6 reels DNA symmetrically into loops at a force-dependent rate of one kilobase pair per second. Smc5/6 extrudes loops in the form of dimers, whereas monomeric Smc5/6 unidirectionally translocates along DNA. We also find that the subunits Nse5 and Nse6 (Nse5/6) act as negative regulators of loop extrusion. Nse5/6 inhibits loop-extrusion initiation by hindering Smc5/6 dimerization but has no influence on ongoing loop extrusion. Our findings reveal functions of Smc5/6 at the molecular level and establish DNA loop extrusion as a conserved mechanism among eukaryotic SMC complexes.
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Affiliation(s)
| | - Takaharu Kanno
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Miki Umeda Igarashi
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Mun Siong Loke
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | | | | | - Kristian Jeppsson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Camilla Björkegren
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden.
| | - Eugene Kim
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
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5
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Stabilization of DNA fork junctions by Smc5/6 complexes revealed by single-molecule imaging. Cell Rep 2022; 41:111778. [PMID: 36476856 PMCID: PMC9756111 DOI: 10.1016/j.celrep.2022.111778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 09/15/2022] [Accepted: 11/11/2022] [Indexed: 12/12/2022] Open
Abstract
SMC complexes play key roles in genome maintenance, where they ensure efficient genome replication and segregation. The SMC complex Smc5/6 is a crucial player in DNA replication and repair, yet many molecular features that determine its roles are unclear. Here, we use single-molecule microscopy to investigate Smc5/6's interaction with DNA. We find that Smc5/6 forms oligomers that dynamically redistribute on dsDNA by 1D diffusion and statically bind to ssDNA. Using combined force manipulation and single-molecule microscopy, we generate ssDNA-dsDNA junctions that mimic structures present in DNA repair intermediates or replication forks. We show that Smc5/6 accumulates at these junction sites, stabilizes the fork, and promotes the retention of RPA. Our observations provide a model for the complex's enrichment at sites of replication stress and DNA lesions from where it coordinates the recruitment and activation of downstream repair proteins.
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6
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Smc5/6 silences episomal transcription by a three-step function. Nat Struct Mol Biol 2022; 29:922-931. [PMID: 36097294 DOI: 10.1038/s41594-022-00829-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 07/29/2022] [Indexed: 11/08/2022]
Abstract
In addition to its role in chromosome maintenance, the six-membered Smc5/6 complex functions as a restriction factor that binds to and transcriptionally silences viral and other episomal DNA. However, the underlying mechanism is unknown. Here, we show that transcriptional silencing by the human Smc5/6 complex is a three-step process. The first step is entrapment of the episomal DNA by a mechanism dependent on Smc5/6 ATPase activity and a function of its Nse4a subunit for which the Nse4b paralog cannot substitute. The second step results in Smc5/6 recruitment to promyelocytic leukemia nuclear bodies by SLF2 (the human ortholog of Nse6). The third step promotes silencing through a mechanism requiring Nse2 but not its SUMO ligase activity. By contrast, the related cohesin and condensin complexes fail to bind to or silence episomal DNA, indicating a property unique to Smc5/6.
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7
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Hepatitis B virus-associated hepatocellular carcinoma with Smc5/6 complex deficiency is susceptible to PARP inhibitors. Biochem Biophys Res Commun 2022; 607:89-95. [DOI: 10.1016/j.bbrc.2022.03.137] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 03/25/2022] [Indexed: 12/11/2022]
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8
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Phipps J, Dubrana K. DNA Repair in Space and Time: Safeguarding the Genome with the Cohesin Complex. Genes (Basel) 2022; 13:198. [PMID: 35205243 PMCID: PMC8872453 DOI: 10.3390/genes13020198] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/20/2022] [Accepted: 01/20/2022] [Indexed: 12/04/2022] Open
Abstract
DNA double-strand breaks (DSBs) are a deleterious form of DNA damage, which must be robustly addressed to ensure genome stability. Defective repair can result in chromosome loss, point mutations, loss of heterozygosity or chromosomal rearrangements, which could lead to oncogenesis or cell death. We explore the requirements for the successful repair of DNA DSBs by non-homologous end joining and homology-directed repair (HDR) mechanisms in relation to genome folding and dynamics. On the occurrence of a DSB, local and global chromatin composition and dynamics, as well as 3D genome organization and break localization within the nuclear space, influence how repair proceeds. The cohesin complex is increasingly implicated as a key regulator of the genome, influencing chromatin composition and dynamics, and crucially genome organization through folding chromosomes by an active loop extrusion mechanism, and maintaining sister chromatid cohesion. Here, we consider how this complex is now emerging as a key player in the DNA damage response, influencing repair pathway choice and efficiency.
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Affiliation(s)
| | - Karine Dubrana
- UMR Stabilité Génétique Cellules Souches et Radiations, INSERM, iRCM/IBFJ CEA, Université de Paris and Université Paris-Saclay, F-92265 Fontenay-aux-Roses, France;
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9
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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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10
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3D Genome Organization: Causes and Consequences for DNA Damage and Repair. Genes (Basel) 2021; 13:genes13010007. [PMID: 35052348 PMCID: PMC8775012 DOI: 10.3390/genes13010007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/16/2021] [Accepted: 12/18/2021] [Indexed: 01/02/2023] Open
Abstract
The inability to repair damaged DNA severely compromises the integrity of any organism. In eukaryotes, the DNA damage response (DDR) operates within chromatin, a tightly organized DNA–histone complex in a non-random manner within the nucleus. Chromatin thus orchestrates various cellular processes, including repair. Here, we examine the chromatin landscape before, during, and after the DNA damage, focusing on double strand breaks (DSBs). We study how chromatin is modified during the repair process, not only around the damaged region (in cis), but also genome-wide (in trans). Recent evidence has highlighted a complex landscape in which different chromatin parameters (stiffness, compaction, loops) are transiently modified, defining “codes” for each specific stage of the DDR. We illustrate a novel aspect of DDR where chromatin modifications contribute to the movement of DSB-damaged chromatin, as well as undamaged chromatin, ensuring the mobilization of DSBs, their clustering, and their repair processes.
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11
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Smc5/6, an atypical SMC complex with two RING-type subunits. Biochem Soc Trans 2021; 48:2159-2171. [PMID: 32964921 DOI: 10.1042/bst20200389] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 01/06/2023]
Abstract
The Smc5/6 complex plays essential roles in chromosome segregation and repair, by promoting disjunction of sister chromatids. The core of the complex is constituted by an heterodimer of Structural Maintenance of Chromosomes (SMC) proteins that use ATP hydrolysis to dynamically associate with and organize chromosomes. In addition, the Smc5/6 complex contains six non-SMC subunits. Remarkably, and differently to other SMC complexes, the Nse1 and Nse2 subunits contain RING-type domains typically found in E3 ligases, pointing to the capacity to regulate other proteins and complexes through ubiquitin-like modifiers. Nse2 codes for a C-terminal SP-RING domain with SUMO ligase activity, assisting Smc5/6 functions in chromosome segregation through sumoylation of several chromosome-associated proteins. Nse1 codes for a C-terminal NH-RING domain and, although it has been proposed to have ubiquitin ligase activity, no Smc5/6-dependent ubiquitylation target has been described to date. Here, we review the function of the two RING domains of the Smc5/6 complex in the broader context of SMC complexes as global chromosome organizers of the genome.
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12
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Wang XF, Yang SA, Gong S, Chang CH, Portilla JM, Chatterjee D, Irianto J, Bao H, Huang YC, Deng WM. Polyploid mitosis and depolyploidization promote chromosomal instability and tumor progression in a Notch-induced tumor model. Dev Cell 2021; 56:1976-1988.e4. [PMID: 34146466 DOI: 10.1016/j.devcel.2021.05.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 03/18/2021] [Accepted: 05/27/2021] [Indexed: 02/07/2023]
Abstract
Ploidy variation is a cancer hallmark and is frequently associated with poor prognosis in high-grade cancers. Using a Drosophila solid-tumor model where oncogenic Notch drives tumorigenesis in a transition-zone microenvironment in the salivary gland imaginal ring, we find that the tumor-initiating cells normally undergo endoreplication to become polyploid. Upregulation of Notch signaling, however, induces these polyploid transition-zone cells to re-enter mitosis and undergo tumorigenesis. Growth and progression of the transition-zone tumor are fueled by a combination of polyploid mitosis, endoreplication, and depolyploidization. Both polyploid mitosis and depolyploidization are error prone, resulting in chromosomal copy-number variation and polyaneuploidy. Comparative RNA-seq and epistasis analysis reveal that the DNA-damage response genes, also active during meiosis, are upregulated in these tumors and are required for the ploidy-reduction division. Together, these findings suggest that polyploidy and associated cell-cycle variants are critical for increased tumor-cell heterogeneity and genome instability during cancer progression.
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Affiliation(s)
- Xian-Feng Wang
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Sheng-An Yang
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Shangyu Gong
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Chih-Hsuan Chang
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Juan Martin Portilla
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Deeptiman Chatterjee
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Jerome Irianto
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Hongcun Bao
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Yi-Chun Huang
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Wu-Min Deng
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA; Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA.
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13
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Parts L, Batté A, Lopes M, Yuen MW, Laver M, San Luis BJ, Yue JX, Pons C, Eray E, Aloy P, Liti G, van Leeuwen J. Natural variants suppress mutations in hundreds of essential genes. Mol Syst Biol 2021; 17:e10138. [PMID: 34042294 PMCID: PMC8156963 DOI: 10.15252/msb.202010138] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 01/04/2023] Open
Abstract
The consequence of a mutation can be influenced by the context in which it operates. For example, loss of gene function may be tolerated in one genetic background, and lethal in another. The extent to which mutant phenotypes are malleable, the architecture of modifiers and the identities of causal genes remain largely unknown. Here, we measure the fitness effects of ~ 1,100 temperature‐sensitive alleles of yeast essential genes in the context of variation from ten different natural genetic backgrounds and map the modifiers for 19 combinations. Altogether, fitness defects for 149 of the 580 tested genes (26%) could be suppressed by genetic variation in at least one yeast strain. Suppression was generally driven by gain‐of‐function of a single, strong modifier gene, and involved both genes encoding complex or pathway partners suppressing specific temperature‐sensitive alleles, as well as general modifiers altering the effect of many alleles. The emerging frequency of suppression and range of possible mechanisms suggest that a substantial fraction of monogenic diseases could be managed by modulating other gene products.
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Affiliation(s)
- Leopold Parts
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada.,Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK.,Department of Computer Science, University of Tartu, Tartu, Estonia
| | - Amandine Batté
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Maykel Lopes
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Michael W Yuen
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Meredith Laver
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Bryan-Joseph San Luis
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Jia-Xing Yue
- University of Côte d'Azur, CNRS, INSERM, IRCAN, Nice, France
| | - Carles Pons
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute for Science and Technology, Barcelona, Spain
| | - Elise Eray
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Patrick Aloy
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute for Science and Technology, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Gianni Liti
- University of Côte d'Azur, CNRS, INSERM, IRCAN, Nice, France
| | - Jolanda van Leeuwen
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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14
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Unique Features of Hepatitis B Virus-Related Hepatocellular Carcinoma in Pathogenesis and Clinical Significance. Cancers (Basel) 2021; 13:cancers13102454. [PMID: 34070067 PMCID: PMC8158142 DOI: 10.3390/cancers13102454] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/12/2021] [Accepted: 05/14/2021] [Indexed: 02/07/2023] Open
Abstract
Simple Summary Hepatitis B virus (HBV) infection is the major risk factor for hepatocellular carcinoma (HCC). Understanding the unique features for HBV-induced HCC can shed new light on the unmet needs in its early diagnosis and effective therapy. During decades of chronic hepatitis B, hepatocytes undergoing repeated damage and regeneration accumulate genetic changes predisposing to HCC development. In addition to traditional mutations in viral and cellular oncogenes, HBV integration into the cell chromosomes is an alternative genetic change contributing to hepatocarcinogenesis. A striking male dominance in HBV-related HCC further highlights an interaction between androgen sex hormone and viral factors, which contributes to the gender difference via stimulating viral replication and activation of oncogenes preferentially in male patients. Meanwhile, a novel circulating tumor biomarker generated by HBV integration shows great potential for the early diagnosis of HCC. These unique HBV-induced hepatocarcinogenic mechanisms provide new insights for the future development of superior diagnosis and treatment strategies. Abstract Hepatitis B virus (HBV) infection is one of the important risk factors for hepatocellular carcinoma (HCC) worldwide, accounting for around 50% of cases. Chronic hepatitis B infection generates an inflammatory microenvironment, in which hepatocytes undergoing repeated cycles of damage and regeneration accumulate genetic mutations predisposing them to cancer. A striking male dominance in HBV-related HCC highlights the influence of sex hormones which interact with viral factors to influence carcinogenesis. HBV is also considered an oncogenic virus since its X and surface mutant proteins showed tumorigenic activity in mouse models. The other unique mechanism is the insertional mutagenesis by integration of HBV genome into hepatocyte chromosomes to activate oncogenes. HCC survival largely depends on tumor stages at diagnosis and effective treatment. However, early diagnosis by the conventional protein biomarkers achieves limited success. A new biomarker, the circulating virus–host chimera DNA from HBV integration sites in HCC, provides a liquid biopsy approach for monitoring the tumor load in the majority of HBV–HCC patients. To maximize the efficacy of new immunotherapies or molecular target therapies, it requires better classification of HCC based on the tumor microenvironment and specific carcinogenic pathways. An in-depth study may benefit both the diagnosis and treatment of HBV-related HCC.
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15
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Etheridge TJ, Villahermosa D, Campillo-Funollet E, Herbert AD, Irmisch A, Watson AT, Dang HQ, Osborne MA, Oliver AW, Carr AM, Murray JM. Live-cell single-molecule tracking highlights requirements for stable Smc5/6 chromatin association in vivo. eLife 2021; 10:e68579. [PMID: 33860765 PMCID: PMC8075580 DOI: 10.7554/elife.68579] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 04/15/2021] [Indexed: 12/17/2022] Open
Abstract
The essential Smc5/6 complex is required in response to replication stress and is best known for ensuring the fidelity of homologous recombination. Using single-molecule tracking in live fission yeast to investigate Smc5/6 chromatin association, we show that Smc5/6 is chromatin associated in unchallenged cells and this depends on the non-SMC protein Nse6. We define a minimum of two Nse6-dependent sub-pathways, one of which requires the BRCT-domain protein Brc1. Using defined mutants in genes encoding the core Smc5/6 complex subunits, we show that the Nse3 double-stranded DNA binding activity and the arginine fingers of the two Smc5/6 ATPase binding sites are critical for chromatin association. Interestingly, disrupting the single-stranded DNA (ssDNA) binding activity at the hinge region does not prevent chromatin association but leads to elevated levels of gross chromosomal rearrangements during replication restart. This is consistent with a downstream function for ssDNA binding in regulating homologous recombination.
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Affiliation(s)
- Thomas J Etheridge
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Desiree Villahermosa
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Eduard Campillo-Funollet
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Alex David Herbert
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Anja Irmisch
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Adam T Watson
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Hung Q Dang
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Mark A Osborne
- Chemistry Department, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Antony W Oliver
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Antony M Carr
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Johanne M Murray
- Genome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
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16
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Gong W, Song X, Xie C, Zhou Y, Zhu Z, Xu C, Peng Y. Landscape of meiotic crossovers in Hericium erinaceus. Microbiol Res 2021; 245:126692. [PMID: 33453565 DOI: 10.1016/j.micres.2020.126692] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/10/2020] [Accepted: 12/30/2020] [Indexed: 10/22/2022]
Abstract
Meiotic crossover shows marked interspecific and intraspecific variation, and knowledge about the molecular mechanism of crossover variation remains limited. Herein, we described the genome-wide scanning of crossover in one mushroom-forming fungus Hericium erinaceus. Utilizing the whole-genome single-nucleotide polymorphism (SNP) data-sets of a 127 F1 haploid progeny, we localized a total of 1316 crossover events and found that they were more likely to occur in the genic than intergenic regions. More than 30 % of the crossovers were concentrated in 59 crossover hotspots that were preferentially located close to chromosome ends. We then examined the genomic features around crossover hotspots. Results showed that the crossover hotspots were associated with increased gene density and guanine-cytosine (GC) content. An 8-bp GC-rich motif (GCGTCAGC) was found to be significantly enriched in these hotspots. The presence of mating-type loci affected the crossover at local scale rather than the overall crossover number. In order to dissect the genetic mechanisms shaping crossover variation, we then conducted quantitative trait locus (QTL) mapping for the total crossovers (TCO) and the crossover events that solely occurred within hotspots (HCO). Genome-wide QTL scanning identified four TCO-QTLs and two HCO-QTLs, which all located within or next to the crossover-hotspots. Crossover variations were shaped by multiple small-effect loci, with individual QTL contributing 6.9 %-11.7 % of variation. A few recombination pathway genes, including Spo11, Msh5, and Smc5 were found to be co-localized with the mapped crossover QTLs. Taken together, findings of this study offer insights into the crossover distribution and genetic factors conferring crossover variation in H. erinaceus, and advance our understandings for meiotic recombination in mushroom-forming fungi.
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Affiliation(s)
- Wenbing Gong
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Xiaoya Song
- Lishui Academy of Agricultural and Forestry Sciences, Lishui 323000, PR China
| | - Chunliang Xie
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Yingjun Zhou
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Zuohua Zhu
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Chao Xu
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Yuande Peng
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China.
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17
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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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18
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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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19
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Rossi F, Helbling‐Leclerc A, Kawasumi R, Jegadesan NK, Xu X, Devulder P, Abe T, Takata M, Xu D, Rosselli F, Branzei D. SMC5/6 acts jointly with Fanconi anemia factors to support DNA repair and genome stability. EMBO Rep 2020; 21:e48222. [PMID: 31867888 PMCID: PMC7001510 DOI: 10.15252/embr.201948222] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 11/19/2019] [Accepted: 11/21/2019] [Indexed: 12/21/2022] Open
Abstract
SMC5/6 function in genome integrity remains elusive. Here, we show that SMC5 dysfunction in avian DT40 B cells causes mitotic delay and hypersensitivity toward DNA intra- and inter-strand crosslinkers (ICLs), with smc5 mutants being epistatic to FANCC and FANCM mutations affecting the Fanconi anemia (FA) pathway. Mutations in the checkpoint clamp loader RAD17 and the DNA helicase DDX11, acting in an FA-like pathway, do not aggravate the damage sensitivity caused by SMC5 dysfunction in DT40 cells. SMC5/6 knockdown in HeLa cells causes MMC sensitivity, increases nuclear bridges, micronuclei, and mitotic catastrophes in a manner similar and non-additive to FANCD2 knockdown. In both DT40 and HeLa systems, SMC5/6 deficiency does not affect FANCD2 ubiquitylation and, unlike FANCD2 depletion, RAD51 focus formation. SMC5/6 components further physically interact with FANCD2-I in human cells. Altogether, our data suggest that SMC5/6 functions jointly with the FA pathway to support genome integrity and DNA repair and may be implicated in FA or FA-related human disorders.
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Affiliation(s)
| | - Anne Helbling‐Leclerc
- UMR8200 CNRSEquipe Labellisée La Ligue Contre le CancerUniversité Paris SudGustave RoussyVillejuif CedexFrance
| | | | | | - Xinlin Xu
- School of Life SciencesPeking UniversityBeijingChina
| | - Pierre Devulder
- UMR8200 CNRSEquipe Labellisée La Ligue Contre le CancerUniversité Paris SudGustave RoussyVillejuif CedexFrance
| | - Takuya Abe
- The FIRC Institute of Molecular OncologyIFOMMilanItaly
- Present address:
Department of ChemistryGraduate School of ScienceTokyo Metropolitan UniversityHachioji‐shiTokyoJapan
| | - Minoru Takata
- Laboratory of DNA Damage SignalingRadiation Biology CenterGraduate School of BiostudiesKyoto UniversityKyotoJapan
| | - Dongyi Xu
- School of Life SciencesPeking UniversityBeijingChina
| | - Filippo Rosselli
- UMR8200 CNRSEquipe Labellisée La Ligue Contre le CancerUniversité Paris SudGustave RoussyVillejuif CedexFrance
| | - Dana Branzei
- The FIRC Institute of Molecular OncologyIFOMMilanItaly
- Istituto di Genetica MolecolareConsiglio Nazionale delle Ricerche (IGM‐CNR)PaviaItaly
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20
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Gaillard H, Santos-Pereira JM, Aguilera A. The Nup84 complex coordinates the DNA damage response to warrant genome integrity. Nucleic Acids Res 2019; 47:4054-4067. [PMID: 30715474 PMCID: PMC6486642 DOI: 10.1093/nar/gkz066] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 01/24/2019] [Accepted: 01/25/2019] [Indexed: 02/07/2023] Open
Abstract
DNA lesions interfere with cellular processes such as transcription and replication and need to be adequately resolved to warrant genome integrity. Beyond their primary role in molecule transport, nuclear pore complexes (NPCs) function in other processes such as transcription, nuclear organization and DNA double strand break (DSB) repair. Here we found that the removal of UV-induced DNA lesions by nucleotide excision repair (NER) is compromised in the absence of the Nup84 nuclear pore component. Importantly, nup84Δ cells show an exacerbated sensitivity to UV in early S phase and delayed replication fork progression, suggesting that unrepaired spontaneous DNA lesions persist during S phase. In addition, nup84Δ cells are defective in the repair of replication-born DSBs by sister chromatid recombination (SCR) and rely on post-replicative repair functions for normal proliferation, indicating dysfunctions in the cellular pathways that enable replication on damaged DNA templates. Altogether, our data reveal a central role of the NPC in the DNA damage response to facilitate replication progression through damaged DNA templates by promoting efficient NER and SCR and preventing chromosomal rearrangements.
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Affiliation(s)
- Hélène Gaillard
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - José M Santos-Pereira
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
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21
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Ortega P, Gómez-González B, Aguilera A. Rpd3L and Hda1 histone deacetylases facilitate repair of broken forks by promoting sister chromatid cohesion. Nat Commun 2019; 10:5178. [PMID: 31729385 PMCID: PMC6858524 DOI: 10.1038/s41467-019-13210-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/22/2019] [Indexed: 12/13/2022] Open
Abstract
Genome stability involves accurate replication and DNA repair. Broken replication forks, such as those encountering a nick, lead to double strand breaks (DSBs), which are preferentially repaired by sister-chromatid recombination (SCR). To decipher the role of chromatin in eukaryotic DSB repair, here we analyze a collection of yeast chromatin-modifying mutants using a previously developed system for the molecular analysis of repair of replication-born DSBs by SCR based on a mini-HO site. We confirm the candidates through FLP-based systems based on a mutated version of the FLP flipase that causes nicks on either the leading or lagging DNA strands. We demonstrate that Rpd3L and Hda1 histone deacetylase (HDAC) complexes contribute to the repair of replication-born DSBs by facilitating cohesin loading, with no effect on other types of homology-dependent repair, thus preventing genome instability. We conclude that histone deacetylation favors general sister chromatid cohesion as a necessary step in SCR.
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Affiliation(s)
- Pedro Ortega
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Belén Gómez-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain.
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain.
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22
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Winczura A, Appanah R, Tatham MH, Hay RT, De Piccoli G. The S phase checkpoint promotes the Smc5/6 complex dependent SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε. PLoS Genet 2019; 15:e1008427. [PMID: 31765407 PMCID: PMC6876773 DOI: 10.1371/journal.pgen.1008427] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 09/16/2019] [Indexed: 12/31/2022] Open
Abstract
Replication fork stalling and accumulation of single-stranded DNA trigger the S phase checkpoint, a signalling cascade that, in budding yeast, leads to the activation of the Rad53 kinase. Rad53 is essential in maintaining cell viability, but its targets of regulation are still partially unknown. Here we show that Rad53 drives the hyper-SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε, principally following replication forks stalling induced by nucleotide depletion. Pol2 is the main target of SUMOylation within the replisome and its modification requires the SUMO-ligase Mms21, a subunit of the Smc5/6 complex. Moreover, the Smc5/6 complex co-purifies with Pol ε, independently of other replisome components. Finally, we map Pol2 SUMOylation to a single site within the N-terminal catalytic domain and identify a SUMO-interacting motif at the C-terminus of Pol2. These data suggest that the S phase checkpoint regulate Pol ε during replication stress through Pol2 SUMOylation and SUMO-binding ability.
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Affiliation(s)
- Alicja Winczura
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Rowin Appanah
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Michael H. Tatham
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, United Kingdom
| | - Ronald T. Hay
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, United Kingdom
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23
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Essential Saccharomyces cerevisiae genome instability suppressing genes identify potential human tumor suppressors. Proc Natl Acad Sci U S A 2019; 116:17377-17382. [PMID: 31409704 DOI: 10.1073/pnas.1906921116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Gross Chromosomal Rearrangements (GCRs) play an important role in human diseases, including cancer. Although most of the nonessential Genome Instability Suppressing (GIS) genes in Saccharomyces cerevisiae are known, the essential genes in which mutations can cause increased GCR rates are not well understood. Here 2 S. cerevisiae GCR assays were used to screen a targeted collection of temperature-sensitive mutants to identify mutations that caused increased GCR rates. This identified 94 essential GIS (eGIS) genes in which mutations cause increased GCR rates and 38 candidate eGIS genes that encode eGIS1 protein-interacting or family member proteins. Analysis of TCGA data using the human genes predicted to encode the proteins and protein complexes implicated by the S. cerevisiae eGIS genes revealed a significant enrichment of mutations affecting predicted human eGIS genes in 10 of the 16 cancers analyzed.
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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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25
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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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26
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Pond KW, de Renty C, Yagle MK, Ellis NA. Rescue of collapsed replication forks is dependent on NSMCE2 to prevent mitotic DNA damage. PLoS Genet 2019; 15:e1007942. [PMID: 30735491 PMCID: PMC6383951 DOI: 10.1371/journal.pgen.1007942] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 02/21/2019] [Accepted: 01/07/2019] [Indexed: 12/12/2022] Open
Abstract
NSMCE2 is an E3 SUMO ligase and a subunit of the SMC5/6 complex that associates with the replication fork and protects against genomic instability. Here, we study the fate of collapsed replication forks generated by prolonged hydroxyurea treatment in human NSMCE2-deficient cells. Double strand breaks accumulate during rescue by converging forks in normal cells but not in NSMCE2-deficient cells. Un-rescued forks persist into mitosis, leading to increased mitotic DNA damage. Excess RAD51 accumulates and persists at collapsed forks in NSMCE2-deficient cells, possibly due to lack of BLM recruitment to stalled forks. Despite failure of BLM to accumulate at stalled forks, NSMCE2-deficient cells exhibit lower levels of hydroxyurea-induced sister chromatid exchange. In cells deficient in both NSMCE2 and BLM, hydroxyurea-induced double strand breaks and sister chromatid exchange resembled levels found in NSCME2-deficient cells. We conclude that the rescue of collapsed forks by converging forks is dependent on NSMCE2. DNA damage encountered by the replication fork causes fork stalling and is a major source of mutations when not adequately repaired. Fork stalling can lead to fork collapse, that is, a state of the fork in which normal DNA synthesis cannot be resumed at the site of stalling. Collapsed forks must be rescued by replication forks initiated nearby, but little is known about the rescue mechanism by which an active fork merges with a collapsed fork. We used an inhibitor of DNA replication to generate collapsed replication forks and then studied genetic control of collapsed-fork rescue. We found that NSMCE2, which is a gene product that is known to regulate repair responses to replication stress, is required for cells to effectively rescue collapsed replication forks in order to complete DNA synthesis. DNA double strand breaks that are associated with normal collapsed-fork rescue do not accumulate in cells that are deficient for NSMCE2, suggesting that DNA breakage is part of the rescue and repair mechanism. Failure to rescue collapsed forks leads to DNA damage in mitosis and DNA damage in the following cell cycle. Our work highlights a unique role for NSMCE2 in rescue of collapsed replication forks.
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Affiliation(s)
- Kelvin W. Pond
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, United States of America
| | - Christelle de Renty
- University of Arizona Cancer Center, University of Arizona, Tucson, Arizona, United States of America
| | - Mary K. Yagle
- University of Arizona Cancer Center, University of Arizona, Tucson, Arizona, United States of America
| | - Nathan A. Ellis
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, United States of America
- University of Arizona Cancer Center, University of Arizona, Tucson, Arizona, United States of America
- * E-mail:
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27
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Klein HL, Bačinskaja G, Che J, Cheblal A, Elango R, Epshtein A, Fitzgerald DM, Gómez-González B, Khan SR, Kumar S, Leland BA, Marie L, Mei Q, Miné-Hattab J, Piotrowska A, Polleys EJ, Putnam CD, Radchenko EA, Saada AA, Sakofsky CJ, Shim EY, Stracy M, Xia J, Yan Z, Yin Y, Aguilera A, Argueso JL, Freudenreich CH, Gasser SM, Gordenin DA, Haber JE, Ira G, Jinks-Robertson S, King MC, Kolodner RD, Kuzminov A, Lambert SA, Lee SE, Miller KM, Mirkin SM, Petes TD, Rosenberg SM, Rothstein R, Symington LS, Zawadzki P, Kim N, Lisby M, Malkova A. Guidelines for DNA recombination and repair studies: Cellular assays of DNA repair pathways. MICROBIAL CELL 2019; 6:1-64. [PMID: 30652105 PMCID: PMC6334234 DOI: 10.15698/mic2019.01.664] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Understanding the plasticity of genomes has been greatly aided by assays for recombination, repair and mutagenesis. These assays have been developed in microbial systems that provide the advantages of genetic and molecular reporters that can readily be manipulated. Cellular assays comprise genetic, molecular, and cytological reporters. The assays are powerful tools but each comes with its particular advantages and limitations. Here the most commonly used assays are reviewed, discussed, and presented as the guidelines for future studies.
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Affiliation(s)
- Hannah L Klein
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Giedrė Bačinskaja
- Department of Biology, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Jun Che
- Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, USA
| | - Anais Cheblal
- Friedrich Miescher Institute for Biomedical Research (FMI), 4058 Basel, Switzerland
| | - Rajula Elango
- Department of Biology, University of Iowa, Iowa City, IA, USA
| | - Anastasiya Epshtein
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Devon M Fitzgerald
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Belén Gómez-González
- Centro Andaluz de BIología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, Seville, Spain
| | - Sharik R Khan
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Sandeep Kumar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | | | - Léa Marie
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA
| | - Qian Mei
- Systems, Synthetic and Physical Biology Graduate Program, Rice University, Houston, TX, USA
| | - Judith Miné-Hattab
- Institut Curie, PSL Research University, CNRS, UMR3664, F-75005 Paris, France.,Sorbonne Université, Institut Curie, CNRS, UMR3664, F-75005 Paris, France
| | - Alicja Piotrowska
- NanoBioMedical Centre, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland
| | | | - Christopher D Putnam
- Ludwig Institute for Cancer Research, University of California School of Medicine, San Diego, La Jolla, CA, USA.,Department of Medicine, University of California School of Medicine, San Diego, La Jolla, CA, USA
| | | | - Anissia Ait Saada
- Institut Curie, PSL Research University, CNRS, UMR3348 F-91405, Orsay, France.,University Paris Sud, Paris-Saclay University, CNRS, UMR3348, F-91405, Orsay, France
| | - Cynthia J Sakofsky
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Durham, NC, USA
| | - Eun Yong Shim
- Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, USA
| | - Mathew Stracy
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Jun Xia
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Zhenxin Yan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Yi Yin
- Department of Molecular Genetics and Microbiology and University Program in Genetics and Genomics, Duke University Medical Center, Durham, NC USA
| | - Andrés Aguilera
- Centro Andaluz de BIología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, Seville, Spain
| | - Juan Lucas Argueso
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - Catherine H Freudenreich
- Department of Biology, Tufts University, Medford, MA USA.,Program in Genetics, Tufts University, Boston, MA, USA
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research (FMI), 4058 Basel, Switzerland
| | - Dmitry A Gordenin
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Durham, NC, USA
| | - James E Haber
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center Brandeis University, Waltham, MA, USA
| | - Grzegorz Ira
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Sue Jinks-Robertson
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC USA
| | | | - Richard D Kolodner
- Ludwig Institute for Cancer Research, University of California School of Medicine, San Diego, La Jolla, CA, USA.,Department of Cellular and Molecular Medicine, University of California School of Medicine, San Diego, La Jolla, CA, USA.,Moores-UCSD Cancer Center, University of California School of Medicine, San Diego, La Jolla, CA, USA.,Institute of Genomic Medicine, University of California School of Medicine, San Diego, La Jolla, CA, USA
| | - Andrei Kuzminov
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Sarah Ae Lambert
- Institut Curie, PSL Research University, CNRS, UMR3348 F-91405, Orsay, France.,University Paris Sud, Paris-Saclay University, CNRS, UMR3348, F-91405, Orsay, France
| | - Sang Eun Lee
- Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, USA
| | - Kyle M Miller
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | | | - Thomas D Petes
- Department of Molecular Genetics and Microbiology and University Program in Genetics and Genomics, Duke University Medical Center, Durham, NC USA
| | - Susan M Rosenberg
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.,Systems, Synthetic and Physical Biology Graduate Program, Rice University, Houston, TX, USA
| | - Rodney Rothstein
- Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY, USA
| | - Lorraine S Symington
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA
| | - Pawel Zawadzki
- NanoBioMedical Centre, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland
| | - Nayun Kim
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Michael Lisby
- Department of Biology, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Anna Malkova
- Department of Biology, University of Iowa, Iowa City, IA, USA
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28
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Abstract
The structural maintenance of chromosomes (SMC) complex, SMC5/6, is important for genome maintenance in all model eukaryotes. To date, the most extensive studies have focused on the roles of Smc5/6 in lower eukaryotes, such as yeast and fly. In the handful of studies that have used mammalian cells, siRNA was used by most to knockdown SMC5/6 components. RNAi methods have been very important for scientific progression, but they are hindered by incomplete silencing of protein expression and off-target effects. This chapter outlines the use of a conditional knockout approach in mouse embryonic fibroblasts to study the function of the SMC5/6 complex. These cell lines provide an alternative method to study the function and properties of the SMC5/6 complex in mammals.
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Affiliation(s)
- Himaja Gaddipati
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Marina V Pryzhkova
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Philip W Jordan
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
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29
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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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30
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The SMC5/6 Complex Interacts with the Papillomavirus E2 Protein and Influences Maintenance of Viral Episomal DNA. J Virol 2018; 92:JVI.00356-18. [PMID: 29848583 DOI: 10.1128/jvi.00356-18] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/21/2018] [Indexed: 12/31/2022] Open
Abstract
The papillomavirus E2 protein executes numerous essential functions related to viral transcription, replication of viral DNA, and viral genome maintenance. Because E2 lacks enzymatic activity, many of these functions are mediated by interactions with host cellular proteins. Unbiased proteomics approaches have successfully identified a number of E2-host protein interactions. We have extended such studies and have identified and validated the cellular proteins structural maintenance of chromosome 5 (SMC5) and SMC6 as interactors of the viral E2 protein. These two proteins make up the core components of the SMC5/6 complex. The SMC5/6 complex is a member of the conserved structural maintenance of chromosomes (SMC) family of proteins, which are essential for genome maintenance. We have examined the role of SMC5/6 in various E2 functions. Our data suggest that SMC6 is not required for E2-mediated transcriptional activation, E1/E2-mediated transient replication, or differentiation-dependent amplification of viral DNA. Our data, however, suggest a role for SMC5/6 in viral genome maintenance.IMPORTANCE The high-risk human papillomaviruses (HPVs) are the etiological cause of cervical cancer and the most common sexually transmitted infection. While the majority of infections may be asymptomatic or cause only benign lesions, persistent infection with the oncogenic high-risk HPV types may lead to serious diseases, such as cervical cancer, anogenital carcinoma, or head and neck oropharyngeal squamous cell carcinoma. The identification of virus-host protein interactions provides insights into the mechanisms of viral DNA persistence, viral genome replication, and cellular transformation. Elucidating the mechanism of early events in the virus replication cycle as well as of integration of viral DNA into host chromatin may present novel antiviral strategies and targets for counteracting persistent infection. The E2 protein is an important viral regulatory protein whose functions are mediated through interactions with host cell proteins. Here we explore the interaction of E2 with SMC5/6 and the functional consequences.
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31
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Varejão N, Ibars E, Lascorz J, Colomina N, Torres-Rosell J, Reverter D. DNA activates the Nse2/Mms21 SUMO E3 ligase in the Smc5/6 complex. EMBO J 2018; 37:embj.201798306. [PMID: 29769404 DOI: 10.15252/embj.201798306] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 04/11/2018] [Accepted: 04/20/2018] [Indexed: 11/09/2022] Open
Abstract
Modification of chromosomal proteins by conjugation to SUMO is a key step to cope with DNA damage and to maintain the integrity of the genome. The recruitment of SUMO E3 ligases to chromatin may represent one layer of control on protein sumoylation. However, we currently do not understand how cells upregulate the activity of E3 ligases on chromatin. Here we show that the Nse2 SUMO E3 in the Smc5/6 complex, a critical player during recombinational DNA repair, is directly stimulated by binding to DNA Activation of sumoylation requires the electrostatic interaction between DNA and a positively charged patch in the ARM domain of Smc5, which acts as a DNA sensor that subsequently promotes a stimulatory activation of the E3 activity in Nse2. Specific disruption of the interaction between the ARM of Smc5 and DNA sensitizes cells to DNA damage, indicating that this mechanism contributes to DNA repair. These results reveal a mechanism to enhance a SUMO E3 ligase activity by direct DNA binding and to restrict sumoylation in the vicinity of those Smc5/6-Nse2 molecules engaged on DNA.
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Affiliation(s)
- Nathalia Varejão
- Institut de Biotecnologia i de Biomedicina (IBB), Department of de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Eva Ibars
- Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Department of Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
| | - Jara Lascorz
- Institut de Biotecnologia i de Biomedicina (IBB), Department of de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Neus Colomina
- Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Department of Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
| | - Jordi Torres-Rosell
- Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Department of Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
| | - David Reverter
- Institut de Biotecnologia i de Biomedicina (IBB), Department of de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
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32
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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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33
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Negative regulator of E2F transcription factors links cell cycle checkpoint and DNA damage repair. Proc Natl Acad Sci U S A 2018; 115:E3837-E3845. [PMID: 29610335 DOI: 10.1073/pnas.1720094115] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
DNA damage poses a serious threat to genome integrity and greatly affects growth and development. To maintain genome stability, all organisms have evolved elaborate DNA damage response mechanisms including activation of cell cycle checkpoints and DNA repair. Here, we show that the DNA repair protein SNI1, a subunit of the evolutionally conserved SMC5/6 complex, directly links these two processes in Arabidopsis SNI1 binds to the activation domains of E2F transcription factors, the key regulators of cell cycle progression, and represses their transcriptional activities. In turn, E2Fs activate the expression of SNI1, suggesting that E2Fs and SNI1 form a negative feedback loop. Genetically, overexpression of SNI1 suppresses the phenotypes of E2F-overexpressing plants, and loss of E2F function fully suppresses the sni1 mutant, indicating that SNI1 is necessary and sufficient to inhibit E2Fs. Altogether, our study revealed that SNI1 is a negative regulator of E2Fs and plays dual roles in DNA damage responses by linking cell cycle checkpoint and DNA repair.
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34
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SUMO E3 ligase Mms21 prevents spontaneous DNA damage induced genome rearrangements. PLoS Genet 2018; 14:e1007250. [PMID: 29505562 PMCID: PMC5860785 DOI: 10.1371/journal.pgen.1007250] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/20/2018] [Accepted: 02/12/2018] [Indexed: 12/01/2022] Open
Abstract
Mms21, a subunit of the Smc5/6 complex, possesses an E3 ligase activity for the Small Ubiquitin-like MOdifier (SUMO). Here we show that the mms21-CH mutation, which inactivates Mms21 ligase activity, causes increased accumulation of gross chromosomal rearrangements (GCRs) selected in the dGCR assay. These dGCRs are formed by non-allelic homologous recombination between divergent DNA sequences mediated by Rad52-, Rrm3- and Pol32-dependent break-induced replication. Combining mms21-CH with sgs1Δ caused a synergistic increase in GCRs rates, indicating the distinct roles of Mms21 and Sgs1 in suppressing GCRs. The mms21-CH mutation also caused increased rates of accumulating uGCRs mediated by breakpoints in unique sequences as revealed by whole genome sequencing. Consistent with the accumulation of endogenous DNA lesions, mms21-CH mutants accumulate increased levels of spontaneous Rad52 and Ddc2 foci and had a hyper-activated DNA damage checkpoint. Together, these findings support that Mms21 prevents the accumulation of spontaneous DNA lesions that cause diverse GCRs. Chromosomal rearrangement is a hallmark of cancer. Saccharomyces cerevisiae Mms21 is an E3 ligase for Small Ubiquitin like MOdifer (SUMO), which has been shown to have a major role in preventing chromosomal rearrangement. Despite extensive studies about the function of Mms21 in regulating the repair of exogenously induced DNA damage, how Mms21, and its human ortholog NSMCE2, prevents spontaneous chromosomal rearrangement in unperturbed cells has been unknown. In this study, we provided genetic evidences supporting a novel role of Mms21 in preventing the accumulation of spontaneous DNA breaks, which are likely caused by defective DNA replication, without appreciably affecting how they are repaired. Our findings highlight the central role of faithful DNA replication in preventing spontaneous chromosomal rearrangement, and further suggest that the study of the role of Mms21 dependent sumoylation in DNA replication could yield important insights into how the SUMO pathway prevents chromosomal rearrangement in human disease.
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35
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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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36
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Lafuente-Barquero J, Luke-Glaser S, Graf M, Silva S, Gómez-González B, Lockhart A, Lisby M, Aguilera A, Luke B. The Smc5/6 complex regulates the yeast Mph1 helicase at RNA-DNA hybrid-mediated DNA damage. PLoS Genet 2017; 13:e1007136. [PMID: 29281624 PMCID: PMC5760084 DOI: 10.1371/journal.pgen.1007136] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 01/09/2018] [Accepted: 11/28/2017] [Indexed: 01/08/2023] Open
Abstract
RNA-DNA hybrids are naturally occurring obstacles that must be overcome by the DNA replication machinery. In the absence of RNase H enzymes, RNA-DNA hybrids accumulate, resulting in replication stress, DNA damage and compromised genomic integrity. We demonstrate that Mph1, the yeast homolog of Fanconi anemia protein M (FANCM), is required for cell viability in the absence of RNase H enzymes. The integrity of the Mph1 helicase domain is crucial to prevent the accumulation of RNA-DNA hybrids and RNA-DNA hybrid-dependent DNA damage, as determined by Rad52 foci. Mph1 forms foci when RNA-DNA hybrids accumulate, e.g. in RNase H or THO-complex mutants and at short telomeres. Mph1, however is a double-edged sword, whose action at hybrids must be regulated by the Smc5/6 complex. This is underlined by the observation that simultaneous inactivation of RNase H2 and Smc5/6 results in Mph1-dependent synthetic lethality, which is likely due to an accumulation of toxic recombination intermediates. The data presented here support a model, where Mph1’s helicase activity plays a crucial role in responding to persistent RNA-DNA hybrids. DNA damage can either occur exogenously through DNA damaging agents such as UV light and exposure to chemotherapeutics, or endogenously via metabolic, cellular processes. The RNA product of transcription, for example, can engage in the formation of RNA-DNA hybrids. Such RNA-DNA hybrids can impede replication fork progression and cause genomic instability, a hallmark of cancer. The misregulation of RNA-DNA hybrids has also been implicated in several neurological disorders. Recently, it has become evident that RNA-DNA hybrids may also have beneficial roles and therefore, these structures have to be tightly controlled. We found that Mph1 (mutator phenotype 1), the budding yeast homolog of Fanconi Anemia protein M, counteracts the accumulation of RNA-DNA hybrids. The inactivation of MPH1 results in a severe growth defect when combined with mutations in the well-characterized RNase H enzymes, that degrade the RNA moiety of an RNA-DNA hybrid. Based on the data presented here, we propose a model, where Mph1 itself has to be kept in check by the SMC (structural maintenance of chromosome) 5/6 complex at replication forks stalled by RNA-DNA hybrids. Mph1 acts as a double-edged sword, as both its deletion and the inability to control its helicase activity cause DNA damage and growth arrest when RNA-DNA hybrids accumulate.
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Affiliation(s)
- Juan Lafuente-Barquero
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Avda. Americo Vespucio 24, Seville, Spain
| | - Sarah Luke-Glaser
- Institute of Molecular Biology (IMB), Mainz, Germany
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Marco Graf
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Sonia Silva
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Avda. Americo Vespucio 24, Seville, Spain
- Department of Biology, University of Copenhagen, Ole Maaloeesvej 5, Copenhagen N, Denmark
| | - Belén Gómez-González
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Avda. Americo Vespucio 24, Seville, Spain
| | | | - Michael Lisby
- Department of Biology, University of Copenhagen, Ole Maaloeesvej 5, Copenhagen N, Denmark
| | - Andrés Aguilera
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Avda. Americo Vespucio 24, Seville, Spain
- * E-mail: (BL); (AA)
| | - Brian Luke
- Institute of Molecular Biology (IMB), Mainz, Germany
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
- Institute of Neurobiology and Developmental Biology, JGU Mainz, Mainz, Germany
- * E-mail: (BL); (AA)
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37
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Eeftens J, Dekker C. Catching DNA with hoops—biophysical approaches to clarify the mechanism of SMC proteins. Nat Struct Mol Biol 2017; 24:1012-1020. [DOI: 10.1038/nsmb.3507] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/18/2017] [Indexed: 12/11/2022]
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38
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Wani S, Maharshi N, Kothiwal D, Mahendrawada L, Kalaivani R, Laloraya S. Interaction of the Saccharomyces cerevisiae RING-domain protein Nse1 with Nse3 and the Smc5/6 complex is required for chromosome replication and stability. Curr Genet 2017; 64:599-617. [DOI: 10.1007/s00294-017-0776-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 10/27/2017] [Accepted: 10/31/2017] [Indexed: 12/17/2022]
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39
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Pathways and Mechanisms that Prevent Genome Instability in Saccharomyces cerevisiae. Genetics 2017; 206:1187-1225. [PMID: 28684602 PMCID: PMC5500125 DOI: 10.1534/genetics.112.145805] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 04/26/2017] [Indexed: 12/13/2022] Open
Abstract
Genome rearrangements result in mutations that underlie many human diseases, and ongoing genome instability likely contributes to the development of many cancers. The tools for studying genome instability in mammalian cells are limited, whereas model organisms such as Saccharomyces cerevisiae are more amenable to these studies. Here, we discuss the many genetic assays developed to measure the rate of occurrence of Gross Chromosomal Rearrangements (called GCRs) in S. cerevisiae. These genetic assays have been used to identify many types of GCRs, including translocations, interstitial deletions, and broken chromosomes healed by de novo telomere addition, and have identified genes that act in the suppression and formation of GCRs. Insights from these studies have contributed to the understanding of pathways and mechanisms that suppress genome instability and how these pathways cooperate with each other. Integrated models for the formation and suppression of GCRs are discussed.
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Zheng Y, Jongejan A, Mulder CL, Mastenbroek S, Repping S, Wang Y, Li J, Hamer G. Trivial role for NSMCE2 during in vitro proliferation and differentiation of male germline stem cells. Reproduction 2017; 154:181-195. [DOI: 10.1530/rep-17-0173] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/26/2017] [Accepted: 06/02/2017] [Indexed: 12/12/2022]
Abstract
Spermatogenesis, starting with spermatogonial differentiation, is characterized by ongoing and dramatic alterations in composition and function of chromatin. Failure to maintain proper chromatin dynamics during spermatogenesis may lead to mutations, chromosomal aberrations or aneuploidies. When transmitted to the offspring, these can cause infertility or congenital malformations. The structural maintenance of chromosomes (SMC) 5/6 protein complex has recently been described to function in chromatin modeling and genomic integrity maintenance during spermatogonial differentiation and meiosis. Among the subunits of the SMC5/6 complex, non-SMC element 2 (NSMCE2) is an important small ubiquitin-related modifier (SUMO) ligase. NSMCE2 has been reported to be essential for mouse development, prevention of cancer and aging in adult mice and topological stress relief in human somatic cells. By using in vitro cultured primary mouse spermatogonial stem cells (SSCs), referred to as male germline stem (GS) cells, we investigated the function of NSMCE2 during spermatogonial proliferation and differentiation. We first optimized a protocol to generate genetically modified GS cell lines using CRISPR-Cas9 and generated an Nsmce2−/− GS cell line. Using this Nsmce2−/− GS cell line, we found that NSMCE2 was dispensable for proliferation, differentiation and topological stress relief in mouse GS cells. Moreover, RNA sequencing analysis demonstrated that the transcriptome was only minimally affected by the absence of NSMCE2. Only differential expression of Sgsm1 appeared highly significant, but with SGSM1 protein levels being unaffected without NSMCE2. Hence, despite the essential roles of NSMCE2 in somatic cells, chromatin integrity maintenance seems differentially regulated in the germline.
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Muñoz-Galván S, García-Rubio M, Ortega P, Ruiz JF, Jimeno S, Pardo B, Gómez-González B, Aguilera A. A new role for Rrm3 in repair of replication-born DNA breakage by sister chromatid recombination. PLoS Genet 2017; 13:e1006781. [PMID: 28475600 PMCID: PMC5438189 DOI: 10.1371/journal.pgen.1006781] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/19/2017] [Accepted: 04/26/2017] [Indexed: 11/19/2022] Open
Abstract
Replication forks stall at different DNA obstacles such as those originated by transcription. Fork stalling can lead to DNA double-strand breaks (DSBs) that will be preferentially repaired by homologous recombination when the sister chromatid is available. The Rrm3 helicase is a replisome component that promotes replication upon fork stalling, accumulates at highly transcribed regions and prevents not only transcription-induced replication fork stalling but also transcription-associated hyper-recombination. This led us to explore the possible role of Rrm3 in the repair of DSBs when originating at the passage of the replication fork. Using a mini-HO system that induces mainly single-stranded DNA breaks, we show that rrm3Δ cells are defective in DSB repair. The defect is clearly seen in sister chromatid recombination, the major repair pathway of replication-born DSBs. Our results indicate that Rrm3 recruitment to replication-born DSBs is crucial for viability, uncovering a new role for Rrm3 in the repair of broken replication forks. DNA replication needs to be precise to ensure cell survival and to avoid genetic instability. Different DNA obstacles, such as those originated by transcription, frequently hamper replication fork progression leading to fork stalling or even fork breakage. This requires the homologous recombination machinery to repair the damage. Here, we uncovered a role for yeast Rrm3, a replisome component known to promote replication upon fork stalling, in the repair of replication-born double strand breaks. In particular, rrm3Δ cells show a defect in the recombination with the sister chromatid, the preferred template for the maintenance of genome integrity. Our results support the possibility that the known accumulation of Rrm3 at sites of active transcription reflects an active role of Rrm3 in the repair of broken forks.
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Affiliation(s)
- Sandra Muñoz-Galván
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - María García-Rubio
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Pedro Ortega
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Jose F. Ruiz
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Sonia Jimeno
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Benjamin Pardo
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Belén Gómez-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
- * E-mail: (AA); (BGG)
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
- * E-mail: (AA); (BGG)
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Bermúdez-López M, Villoria MT, Esteras M, Jarmuz A, Torres-Rosell J, Clemente-Blanco A, Aragon L. Sgs1's roles in DNA end resection, HJ dissolution, and crossover suppression require a two-step SUMO regulation dependent on Smc5/6. Genes Dev 2017; 30:1339-56. [PMID: 27298337 PMCID: PMC4911932 DOI: 10.1101/gad.278275.116] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/09/2016] [Indexed: 01/10/2023]
Abstract
In this study, Bermudez-Lopez et al. investigated the molecular regulation of the RecQ helicase (Bloom/Sgs1), which plays critical roles during DNA repair by homologous recombination. The authors provide new insights into the regulation of recruitment and activation of Sgs1 at damaged sites by showing that the Sgs1 is recruited and activated at sites of DNA damage by the Smc5/6 complex through SUMOylation. The RecQ helicase Sgs1 plays critical roles during DNA repair by homologous recombination, from end resection to Holliday junction (HJ) dissolution. Sgs1 has both pro- and anti-recombinogenic roles, and therefore its activity must be tightly regulated. However, the controls involved in recruitment and activation of Sgs1 at damaged sites are unknown. Here we show a two-step role for Smc5/6 in recruiting and activating Sgs1 through SUMOylation. First, auto-SUMOylation of Smc5/6 subunits leads to recruitment of Sgs1 as part of the STR (Sgs1–Top3–Rmi1) complex, mediated by two SUMO-interacting motifs (SIMs) on Sgs1 that specifically recognize SUMOylated Smc5/6. Second, Smc5/6-dependent SUMOylation of Sgs1 and Top3 is required for the efficient function of STR. Sgs1 mutants impaired in recognition of SUMOylated Smc5/6 (sgs1-SIMΔ) or SUMO-dead alleles (sgs1-KR) exhibit unprocessed HJs at damaged replication forks, increased crossover frequencies during double-strand break repair, and severe impairment in DNA end resection. Smc5/6 is a key regulator of Sgs1's recombination functions.
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Affiliation(s)
- Marcelino Bermúdez-López
- Cell Cycle Group, MRC Clinical Sciences Centre, Imperial College, London W12 0NN, United Kingdom; Deptartment of Ciències Mèdiques Bàsiques, Institut de Recerca Biomèdica de Lleida, Universitat de Lleida, 25198 Lleida, Spain
| | - María Teresa Villoria
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, 37007 Salamanca, Spain
| | - Miguel Esteras
- Cell Cycle Group, MRC Clinical Sciences Centre, Imperial College, London W12 0NN, United Kingdom
| | - Adam Jarmuz
- Cell Cycle Group, MRC Clinical Sciences Centre, Imperial College, London W12 0NN, United Kingdom
| | - Jordi Torres-Rosell
- Deptartment of Ciències Mèdiques Bàsiques, Institut de Recerca Biomèdica de Lleida, Universitat de Lleida, 25198 Lleida, Spain
| | - Andres Clemente-Blanco
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, 37007 Salamanca, Spain
| | - Luis Aragon
- Cell Cycle Group, MRC Clinical Sciences Centre, Imperial College, London W12 0NN, United Kingdom
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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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Rai R, Laloraya S. Genetic evidence for functional interaction of Smc5/6 complex and Top1 with spatial frequency of replication origins required for maintenance of chromosome stability. Curr Genet 2017; 63:765-776. [PMID: 28204881 DOI: 10.1007/s00294-017-0680-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 01/22/2017] [Accepted: 01/24/2017] [Indexed: 12/27/2022]
Abstract
Replication of linear chromosomes is facilitated by firing of multiple replication origins that ensures timely duplication of the entire chromosome. The Smc5/6 complex is thought to play an important role in replication by its involvement in the restart of collapsed replication forks. Here, we present genetic evidence for functional interaction between replication origin distribution and two subunits of the Smc5/6 complex, Smc6 and Mms21, as well as Top1. An artificial chromosome that has a long arm having low origin density (5ori∆YAC) is relatively unstable compared to the YAC having normal origin distribution in wild-type cells, but is partially stabilized in smc6-56 and top1∆ mutants. While a SUMO-ligase-deficient mutant of Mms21 does not affect stability of the 5ori∆YAC by itself, in combination with top1∆, the 5ori∆YAC is destabilized as evidenced by increased chromosome loss frequency in the mms21∆sl top1∆ double mutant. Likewise, the smc6-56 top1∆ double mutant also exhibits enhanced destabilization of the 5ori∆YAC compared to either single mutant. Such an increase in chromosome loss is not observed for a similar YAC that retains the original replication origins and normal origin distribution on the long arm, in either double mutant having the mms21∆sl or smc6-56 mutations in combination with top1∆. Our findings reveal a requirement for the Smc5/6 complex, including Mms21/Nse2 mediated sumoylation, and topoisomerase-1 (Top1), for maintaining stability of a chromosome having low origin density and suggest a functional cooperation between the Smc5/6 complex and Top1 in maintenance of topologically challenged chromosomes prone to replication fork collapse or accumulation of torsional stress.
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Affiliation(s)
- Ragini Rai
- Department of Biochemistry, Indian Institute of Science, C. V. Raman Avenue, Bangalore, Karnataka, 560012, India
| | - Shikha Laloraya
- Department of Biochemistry, Indian Institute of Science, C. V. Raman Avenue, Bangalore, Karnataka, 560012, India.
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Alt A, Dang HQ, Wells OS, Polo LM, Smith MA, McGregor GA, Welte T, Lehmann AR, Pearl LH, Murray JM, Oliver AW. Specialized interfaces of Smc5/6 control hinge stability and DNA association. Nat Commun 2017; 8:14011. [PMID: 28134253 PMCID: PMC5290277 DOI: 10.1038/ncomms14011] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/21/2016] [Indexed: 01/09/2023] Open
Abstract
The Structural Maintenance of Chromosomes (SMC) complexes: cohesin, condensin and Smc5/6 are involved in the organization of higher-order chromosome structure-which is essential for accurate chromosome duplication and segregation. Each complex is scaffolded by a specific SMC protein dimer (heterodimer in eukaryotes) held together via their hinge domains. Here we show that the Smc5/6-hinge, like those of cohesin and condensin, also forms a toroidal structure but with distinctive subunit interfaces absent from the other SMC complexes; an unusual 'molecular latch' and a functional 'hub'. Defined mutations in these interfaces cause severe phenotypic effects with sensitivity to DNA-damaging agents in fission yeast and reduced viability in human cells. We show that the Smc5/6-hinge complex binds preferentially to ssDNA and that this interaction is affected by both 'latch' and 'hub' mutations, suggesting a key role for these unique features in controlling DNA association by the Smc5/6 complex.
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Affiliation(s)
- Aaron Alt
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, BN1 9RQ, UK
| | - Hung Q. Dang
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Owen S. Wells
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Luis M. Polo
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, BN1 9RQ, UK
| | - Matt A. Smith
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Grant A. McGregor
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Thomas Welte
- Dynamic Biosensors GmbH, Lochhamer Strasse, D-81252 Martinsreid/Planegg, Germany
| | - Alan R. Lehmann
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Laurence H. Pearl
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, BN1 9RQ, UK
| | - Johanne M. Murray
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Antony W. Oliver
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, BN1 9RQ, UK
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Interplay between Top1 and Mms21/Nse2 mediated sumoylation in stable maintenance of long chromosomes. Curr Genet 2016; 63:627-645. [PMID: 27872982 DOI: 10.1007/s00294-016-0665-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/06/2016] [Accepted: 11/14/2016] [Indexed: 01/16/2023]
Abstract
Genetic information in cells is encrypted in DNA molecules forming chromosomes of varying sizes. Accurate replication and partitioning of chromosomes in the crowded cellular milieu is a complex process involving duplication, folding and movement. Longer chromosomes may be more susceptible to mis-segregation or DNA damage and there may exist specialized physiological mechanisms preventing this. Here, we present genetic evidence for such a mechanism which depends on Mms21/Nse2 mediated sumoylation and topoisomerase-1 (Top1) for maintaining stability of longer chromosomes. While mutations inactivating Top1 or the SUMO ligase activity of Mms21 (mms21sl) individually destabilized yeast artificial chromosomes (YACs) to a modest extent, the mms21sl top1 double mutant exhibited a synthetic-sick phenotype, and showed preferential destabilization of the longer chromosome relative to shorter chromosomes. In contrast, an smc6-56 top1 mutant defective in Smc6, another subunit of the Smc5/6 complex, of which Mms21 is a component, did not show such a preferential enhancement in frequency of loss of the longer YAC, indicating that this defect may be specific to the deficiency in SUMO ligase activity of Mms21 in the mms21sl top1 mutants. In addition, mms21sl top1 double mutants harboring a longer fusion derivative of natural yeast chromosomes IV and XII displayed reduced viability, consistent with enhanced chromosome instability, relative to single mutants or the double mutant having the natural (shorter) non-fused chromosomes. Our findings reveal a functional interplay between Mms21 and Top1 in maintenance of longer chromosomes, and suggest that lack of sumoylation of Mms21 targets coupled with Top1 deficiency is a crucial requirement for accurate inheritance of longer chromosomes.
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Verver DE, Zheng Y, Speijer D, Hoebe R, Dekker HL, Repping S, Stap J, Hamer G. Non-SMC Element 2 (NSMCE2) of the SMC5/6 Complex Helps to Resolve Topological Stress. Int J Mol Sci 2016; 17:ijms17111782. [PMID: 27792189 PMCID: PMC5133783 DOI: 10.3390/ijms17111782] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 09/14/2016] [Accepted: 10/20/2016] [Indexed: 01/05/2023] Open
Abstract
The structural maintenance of chromosomes (SMC) protein complexes shape and regulate the structure and dynamics of chromatin, thereby controlling many chromosome-based processes such as cell cycle progression, differentiation, gene transcription and DNA repair. The SMC5/6 complex is previously described to promote DNA double-strand breaks (DSBs) repair by sister chromatid recombination, and found to be essential for resolving recombination intermediates during meiotic recombination. Moreover, in budding yeast, SMC5/6 provides structural organization and topological stress relief during replication in mitotically dividing cells. Despite the essential nature of the SMC5/6 complex, the versatile mechanisms by which SMC5/6 functions and its molecular regulation in mammalian cells remain poorly understood. By using a human osteosarcoma cell line (U2OS), we show that after the CRISPR-Cas9-mediated removal of the SMC5/6 subunit NSMCE2, treatment with the topoisomerase II inhibitor etoposide triggered an increased sensitivity in cells lacking NSMCE2. In contrast, NSMCE2 appeared not essential for a proper DNA damage response or cell survival after DSB induction by ionizing irradiation (IR). Interestingly, by way of immunoprecipitations (IPs) and mass spectrometry, we found that the SMC5/6 complex physically interacts with the DNA topoisomerase II α (TOP2A). We therefore propose that the SMC5/6 complex functions in resolving TOP2A-mediated DSB-repair intermediates generated during replication.
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Affiliation(s)
- Dideke E Verver
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
| | - Yi Zheng
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
| | - Dave Speijer
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
| | - Ron Hoebe
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
| | - Henk L Dekker
- Mass Spectrometry of Biomacromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE Amsterdam, The Netherlands.
| | - Sjoerd Repping
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
| | - Jan Stap
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
| | - Geert Hamer
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
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Bermúdez-López M, Aragon L. Smc5/6 complex regulates Sgs1 recombination functions. Curr Genet 2016; 63:381-388. [PMID: 27664093 PMCID: PMC5422486 DOI: 10.1007/s00294-016-0648-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 09/02/2016] [Accepted: 09/03/2016] [Indexed: 11/07/2022]
Abstract
The family of RecQ helicases is evolutionary conserved from bacteria to humans and play key roles in genome stability. The budding yeast RecQ helicase Sgs1 has been implicated in several key processes during the repair of DNA damage by homologous recombination as part of the STR complex (Sgs1-Top3-Rmi1). Limited information on how is Sgs1 recruited and regulated at sites of damage is available. Recently, we and others have uncover a direct link between the Smc5/6 complex and Sgs1. Most roles of Sgs1 during recombination, including DNA end resection, Holiday junction dissolution, and crossover suppression, are regulated through Mms21-dependent SUMOylation. Smc5/6 first acts as a recruiting platform for STR and then SUMOylates STR components to regulate their function. Importantly, the assembly of STR is totally independent of Smc5/6. Here, we provide a brief overview of STR regulation by Smc5/6.
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Affiliation(s)
| | - Luis Aragon
- Cell Cycle Group, MRC Clinical Sciences Centre, Imperial College, London, W12 0NN, UK.
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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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50
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Abstract
SMC (structural maintenance of chromosomes) complexes - which include condensin, cohesin and the SMC5-SMC6 complex - are major components of chromosomes in all living organisms, from bacteria to humans. These ring-shaped protein machines, which are powered by ATP hydrolysis, topologically encircle DNA. With their ability to hold more than one strand of DNA together, SMC complexes control a plethora of chromosomal activities. Notable among these are chromosome condensation and sister chromatid cohesion. Moreover, SMC complexes have an important role in DNA repair. Recent mechanistic insight into the function and regulation of these universal chromosomal machines enables us to propose molecular models of chromosome structure, dynamics and function, illuminating one of the fundamental entities in biology.
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