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Sartsanga C, Phengchat R, Wako T, Fukui K, Ohmido N. Localization and quantitative distribution of a chromatin structural protein Topoisomerase II on plant chromosome using HVTEM and UHVTEM. Micron 2024; 179:103596. [PMID: 38359615 DOI: 10.1016/j.micron.2024.103596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 01/29/2024] [Accepted: 01/29/2024] [Indexed: 02/17/2024]
Abstract
Topoisomerase II (TopoII) is an essential structural protein of the metaphase chromosome. It maintains the axial compaction of chromosomes during metaphase. It is localized at the axial region of chromosomes and accumulates at the centromeric region in metaphase chromosomes. However, little is known about TopoII localization and distribution in plant chromosomes, except for several publications. We used high voltage transmission electron microscopy (HVTEM) and ultra-high voltage transmission electron microscopy (UHVTEM) in conjunction with immunogold labeling and visualization techniques to detect TopoII and investigate its localization, alignment, and density on the barley chromosome at 1.4 nm scale. We found that HVTEM and UHVTEM combined with immunogold labeling is suitable for the detection of structural proteins, including a single molecule of TopoII. This is because the average size of the gold particles for TopoII visualization after silver enhancement is 8.9 ± 3.9 nm, which is well detected. We found that 31,005 TopoII molecules are distributed along the barley chromosomes in an unspecific pattern at the chromosome arms and accumulate specifically at the nucleolus organizer regions (NORs) and centromeric region. The TopoII density were 1.32-fold, 1.58-fold, and 1.36-fold at the terminal region, at the NORs, and the centromeric region, respectively. The findings of TopoII localization in this study support the multiple reported functions of TopoII in the barley metaphase chromosome.
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Affiliation(s)
- Channarong Sartsanga
- Graduate School of Human Development and Environment, Kobe University, Tsurukabuto 3-11, Nada-ku, 657-8501, Kobe, Japan
| | - Rinyaporn Phengchat
- Nanotechnology Research Centre, National Research of Council, 11421 Saskatchewan Drive, T6G 2M9 Edmonton, Alberta, Canada
| | - Toshiyuki Wako
- Institute of Crop Sciences, National Agriculture and Food Research Organization, 2-1-1 Kannondai, Tsukuba, Ibaraki 305-8518, Japan
| | - Kiichi Fukui
- Graduate School of Pharmaceutical Sciences, Osaka University, Yamadaoka 1-6, Suita, Osaka 565-0871, Japan
| | - Nobuko Ohmido
- Graduate School of Human Development and Environment, Kobe University, Tsurukabuto 3-11, Nada-ku, 657-8501, Kobe, Japan.
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2
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Carmo C, Coelho J, Silva RD, Tavares A, Boavida A, Gaetani P, Guilgur LG, Martinho RG, Oliveira RA. A dual-function SNF2 protein drives chromatid resolution and nascent transcripts removal in mitosis. EMBO Rep 2023; 24:e56463. [PMID: 37462213 PMCID: PMC10481674 DOI: 10.15252/embr.202256463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 06/28/2023] [Accepted: 07/03/2023] [Indexed: 09/07/2023] Open
Abstract
Mitotic chromatin is largely assumed incompatible with transcription due to changes in the transcription machinery and chromosome architecture. However, the mechanisms of mitotic transcriptional inactivation and their interplay with chromosome assembly remain largely unknown. By monitoring ongoing transcription in Drosophila early embryos, we reveal that eviction of nascent mRNAs from mitotic chromatin occurs after substantial chromosome compaction and is not promoted by condensin I. Instead, we show that the timely removal of transcripts from mitotic chromatin is driven by the SNF2 helicase-like protein Lodestar (Lds), identified here as a modulator of sister chromatid cohesion defects. In addition to the eviction of nascent transcripts, we uncover that Lds cooperates with Topoisomerase 2 to ensure efficient sister chromatid resolution and mitotic fidelity. We conclude that the removal of nascent transcripts upon mitotic entry is not a passive consequence of cell cycle progression and/or chromosome compaction but occurs via dedicated mechanisms with functional parallelisms to sister chromatid resolution.
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Affiliation(s)
| | - João Coelho
- Instituto Gulbenkian de CiênciaOeirasPortugal
| | - Rui D Silva
- Algarve Biomedical Center Research Institute (ABC‐RI) and Faculty of Medicine and Biomedical Sciences (FMCB)Universidade do AlgarveFaroPortugal
| | | | - Ana Boavida
- Instituto Gulbenkian de CiênciaOeirasPortugal
- Present address:
Istituto di Biochimica e Biologia Cellulare, Consiglio Nazionale delle RicercheNaplesItaly
| | | | | | - Rui Gonçalo Martinho
- Algarve Biomedical Center Research Institute (ABC‐RI) and Faculty of Medicine and Biomedical Sciences (FMCB)Universidade do AlgarveFaroPortugal
- Department of Medical Sciences (DCM) and Institute for Biomedicine (iBiMED)Universidade de AveiroAveiroPortugal
| | - Raquel A Oliveira
- Instituto Gulbenkian de CiênciaOeirasPortugal
- Católica Biomedical Research Centre, Católica Medical SchoolUniversidade Católica PortuguesaLisbonPortugal
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3
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Sundararajan S, Park H, Kawano S, Johansson M, Lama B, Saito-Fujita T, Saitoh N, Arnaoutov A, Dasso M, Wang Z, Keifenheim D, Clarke DJ, Azuma Y. Methylated histones on mitotic chromosomes promote topoisomerase IIα function for high fidelity chromosome segregation. iScience 2023; 26:106743. [PMID: 37197327 PMCID: PMC10183659 DOI: 10.1016/j.isci.2023.106743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/31/2022] [Accepted: 04/21/2023] [Indexed: 05/19/2023] Open
Abstract
DNA Topoisomerase IIα (TopoIIα) decatenates sister chromatids, allowing their segregation in mitosis. Without the TopoIIα Strand Passage Reaction (SPR), chromosome bridges and ultra-fine DNA bridges (UFBs) arise in anaphase. The TopoIIα C-terminal domain is dispensable for the SPR in vitro but essential for mitotic functions in vivo. Here, we present evidence that the Chromatin Tether (ChT) within the CTD interacts with specific methylated nucleosomes and is crucial for high-fidelity chromosome segregation. Mutation of individual αChT residues disrupts αChT-nucleosome interaction, induces loss of segregation fidelity and reduces association of TopoIIα with chromosomes. Specific methyltransferase inhibitors reducing histone H3 or H4 methylation decreased TopoIIα at centromeres and increased segregation errors. Methyltransferase inhibition did not further increase aberrant anaphases in the ChT mutants, indicating a functional connection. The evidence reveals novel cellular regulation whereby TopoIIα specifically interacts with methylated nucleosomes via the αChT to ensure high-fidelity chromosome segregation.
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Affiliation(s)
- Sanjana Sundararajan
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA
| | - Hyewon Park
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA
| | - Shinji Kawano
- Department of Biochemistry, Faculty of Science, Okayama University of Science, Okayama 700-0081, Japan
| | - Marnie Johansson
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Bunu Lama
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA
| | - Tomoko Saito-Fujita
- Division of Cancer Biology, The Cancer Institute of Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan
| | - Noriko Saitoh
- Division of Cancer Biology, The Cancer Institute of Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan
| | - Alexei Arnaoutov
- Division of Molecular and Cellular Biology, National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4480, USA
| | - Mary Dasso
- Division of Molecular and Cellular Biology, National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4480, USA
| | - Zhengqiang Wang
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
| | - Daniel Keifenheim
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Duncan J. Clarke
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yoshiaki Azuma
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA
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4
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Morotomi-Yano K, Hiromoto Y, Higaki T, Yano KI. Disease-associated H58Y mutation affects the nuclear dynamics of human DNA topoisomerase IIβ. Sci Rep 2022; 12:20627. [PMID: 36450898 PMCID: PMC9712534 DOI: 10.1038/s41598-022-24883-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 11/22/2022] [Indexed: 12/12/2022] Open
Abstract
DNA topoisomerase II (TOP2) is an enzyme that resolves DNA topological problems and plays critical roles in various nuclear processes. Recently, a heterozygous H58Y substitution in the ATPase domain of human TOP2B was identified from patients with autism spectrum disorder, but its biological significance remains unclear. In this study, we analyzed the nuclear dynamics of TOP2B with H58Y (TOP2B H58Y). Although wild-type TOP2B was highly mobile in the nucleus of a living cell, the nuclear mobility of TOP2B H58Y was markedly reduced, suggesting that the impact of H58Y manifests as low protein mobility. We found that TOP2B H58Y is insensitive to ICRF-187, a TOP2 inhibitor that halts TOP2 as a closed clamp on DNA. When the ATPase activity of TOP2B was compromised, the nuclear mobility of TOP2B H58Y was restored to wild-type levels, indicating the contribution of the ATPase activity to the low nuclear mobility. Analysis of genome-edited cells harboring TOP2B H58Y showed that TOP2B H58Y retains sensitivity to the TOP2 poison etoposide, implying that TOP2B H58Y can undergo at least a part of its catalytic reactions. Collectively, TOP2 H58Y represents a unique example of the relationship between a disease-associated mutation and perturbed protein dynamics.
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Affiliation(s)
- Keiko Morotomi-Yano
- grid.274841.c0000 0001 0660 6749Institute of Industrial Nanomaterials, Kumamoto University, Kumamoto, Japan
| | - Yukiko Hiromoto
- grid.274841.c0000 0001 0660 6749Faculty of Science, Kumamoto University, Kumamoto, Japan
| | - Takumi Higaki
- grid.274841.c0000 0001 0660 6749Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, Japan ,grid.274841.c0000 0001 0660 6749International Research Organization for Advanced Science and Technology, Kumamoto University, Kumamoto, Japan
| | - Ken-ichi Yano
- grid.274841.c0000 0001 0660 6749Institute of Industrial Nanomaterials, Kumamoto University, Kumamoto, Japan ,grid.274841.c0000 0001 0660 6749Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, Japan
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5
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Jeong J, Lee JH, Carcamo CC, Parker MW, Berger JM. DNA-Stimulated Liquid-Liquid phase separation by eukaryotic topoisomerase ii modulates catalytic function. eLife 2022; 11:e81786. [PMID: 36342377 PMCID: PMC9674351 DOI: 10.7554/elife.81786] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 11/06/2022] [Indexed: 11/09/2022] Open
Abstract
Type II topoisomerases modulate chromosome supercoiling, condensation, and catenation by moving one double-stranded DNA segment through a transient break in a second duplex. How DNA strands are chosen and selectively passed to yield appropriate topological outcomes - for example, decatenation vs. catenation - is poorly understood. Here, we show that at physiological enzyme concentrations, eukaryotic type IIA topoisomerases (topo IIs) readily coalesce into condensed bodies. DNA stimulates condensation and fluidizes these assemblies to impart liquid-like behavior. Condensation induces both budding yeast and human topo IIs to switch from DNA unlinking to active DNA catenation, and depends on an unstructured C-terminal region, the loss of which leads to high levels of knotting and reduced catenation. Our findings establish that local protein concentration and phase separation can regulate how topo II creates or dissolves DNA links, behaviors that can account for the varied roles of the enzyme in supporting transcription, replication, and chromosome compaction.
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Affiliation(s)
- Joshua Jeong
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Joyce H Lee
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Claudia C Carcamo
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Matthew W Parker
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
| | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of MedicineBaltimoreUnited States
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6
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Regulation of the mitotic chromosome folding machines. Biochem J 2022; 479:2153-2173. [PMID: 36268993 DOI: 10.1042/bcj20210140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 09/30/2022] [Accepted: 10/03/2022] [Indexed: 11/17/2022]
Abstract
Over the last several years enormous progress has been made in identifying the molecular machines, including condensins and topoisomerases that fold mitotic chromosomes. The discovery that condensins generate chromatin loops through loop extrusion has revolutionized, and energized, the field of chromosome folding. To understand how these machines fold chromosomes with the appropriate dimensions, while disentangling sister chromatids, it needs to be determined how they are regulated and deployed. Here, we outline the current understanding of how these machines and factors are regulated through cell cycle dependent expression, chromatin localization, activation and inactivation through post-translational modifications, and through associations with each other, with other factors and with the chromatin template itself. There are still many open questions about how condensins and topoisomerases are regulated but given the pace of progress in the chromosome folding field, it seems likely that many of these will be answered in the years ahead.
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7
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Greil C, Engelhardt M, Wäsch R. The Role of the APC/C and Its Coactivators Cdh1 and Cdc20 in Cancer Development and Therapy. Front Genet 2022; 13:941565. [PMID: 35832196 PMCID: PMC9273091 DOI: 10.3389/fgene.2022.941565] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/08/2022] [Indexed: 12/03/2022] Open
Abstract
To sustain genomic stability by correct DNA replication and mitosis, cell cycle progression is tightly controlled by the cyclic activity of cyclin-dependent kinases, their binding to cyclins in the respective phase and the regulation of cyclin levels by ubiquitin-dependent proteolysis. The spindle assembly checkpoint plays an important role at the metaphase-anaphase transition to ensure a correct separation of sister chromatids before cytokinesis and to initiate mitotic exit, as an incorrect chromosome distribution may lead to genetically unstable cells and tumorigenesis. The ubiquitin ligase anaphase-promoting complex or cyclosome (APC/C) is essential for these processes by mediating the proteasomal destruction of cyclins and other important cell cycle regulators. To this end, it interacts with the two regulatory subunits Cdh1 and Cdc20. Both play a role in tumorigenesis with Cdh1 being a tumor suppressor and Cdc20 an oncogene. In this review, we summarize the current knowledge about the APC/C-regulators Cdh1 and Cdc20 in tumorigenesis and potential targeted therapeutic approaches.
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8
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Zheng J, Wu Z, Qiu Y, Wang X, Jiang X. An integrative multi-omics analysis based on liquid–liquid phase separation delineates distinct subtypes of lower-grade glioma and identifies a prognostic signature. J Transl Med 2022; 20:55. [PMID: 35093128 PMCID: PMC8800244 DOI: 10.1186/s12967-022-03266-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/17/2022] [Indexed: 12/11/2022] Open
Abstract
Abstract
Background
Emerging evidences have indicated that the aberrant liquid–liquid phase separation (LLPS) leads to the dysfunction of biomolecular condensates, thereby contributing to the tumorigenesis and progression. Nevertheless, it remains unclear whether or how the LLPS of specific molecules affects the prognosis and tumor immune microenvironment (TIME) of patients with lower-grade glioma (LGG).
Methods
We integrated the transcriptome information of 3585 LLPS-related genes to comprehensively evaluate the LLPS patterns of 423 patients with LGG in The Cancer Genome Atlas (TCGA) cohort. Then, we systematically demonstrated the differences among four LLPS subtypes based on multi-omics analyses. In addition, we constructed the LLPS-related prognostic risk score (LPRS) for individualized integrative assessment.
Results
Based on the expression profiles of 85 scaffolds, 355 regulators, and 3145 clients in LGG, we identified four LLPS subtypes, namely LS1, LS2, LS3 and LS4.
We confirmed that there were significant differences in prognosis, clinicopathological features, cancer hallmarks, genomic alterations, TIME patterns and immunotherapeutic responses among four LLPS subtypes. In addition, a prognostic signature called LPRS was constructed for individualized integrative assessment. LPRS exhibited a robust predictive capacity for prognosis of LGG patients in multiple cohorts. Moreover, LPRS was found to be correlated with clinicopathological features, cancer hallmarks, genomic alterations and TIME patterns of LGG patients. The predictive power of LPRS in response to immune checkpoint inhibitor (ICI) therapy was also prominent.
Conclusions
This study provided a novel classification of LGG patients based on LLPS. The constructed LPRS might facilitate individualized prognosis prediction and better immunotherapy options for LGG patients.
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9
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Live Fluorescence Imaging of Chromosome Segregation in Cultured Cells. Methods Mol Biol 2022; 2415:61-86. [PMID: 34972946 PMCID: PMC10092068 DOI: 10.1007/978-1-0716-1904-9_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Live-cell fluorescence microscopy is an effective tool for characterizing aberrant mitotic phenotypes resulting from exposure to chemical inhibitors and after RNA interference-mediated or CRISPR knockout-mediated depletion of protein targets. Live imaging of cultured cells during mitotic progression presents challenges in maintaining optimal health of cells while achieving the temporal and spatial resolution to accomplish the goals of the study. Herein are strategies to monitor and analyze mammalian cell mitosis utilizing either a wide field or a light sheet, inverted, fluorescence microscope.
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10
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Morovicz AP, Mazloumi Gavgani F, Jacobsen RG, Skuseth Slinning M, Turcu DC, Lewis AE. Phosphoinositide 3-kinase signalling in the nucleolus. Adv Biol Regul 2021; 83:100843. [PMID: 34920983 DOI: 10.1016/j.jbior.2021.100843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 11/20/2021] [Indexed: 12/26/2022]
Abstract
The phosphoinositide 3-kinase (PI3K) signalling pathway plays key roles in many cellular processes and is altered in many diseases. The function and mode of action of the pathway have mostly been elucidated in the cytoplasm. However, many of the components of the PI3K pathway are also present in the nucleus at specific sub-nuclear sites including nuclear speckles, nuclear lipid islets and the nucleolus. Nucleoli are membrane-less subnuclear structures where ribosome biogenesis occurs. Processes leading to ribosome biogenesis are tightly regulated to maintain protein translation capacity of cells. This review focuses on nucleolar PI3K signalling and how it regulates rRNA synthesis, as well as on the identification of downstream phosphatidylinositol (3,4,5)trisphosphate effector proteins.
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Affiliation(s)
| | | | - Rhîan G Jacobsen
- Department of Biological Sciences, University of Bergen, 5008, Bergen, Norway
| | | | - Diana C Turcu
- Department of Biological Sciences, University of Bergen, 5008, Bergen, Norway
| | - Aurélia E Lewis
- Department of Biological Sciences, University of Bergen, 5008, Bergen, Norway.
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11
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Nucleolar translocation of human DNA topoisomerase II by ATP depletion and its disruption by the RNA polymerase I inhibitor BMH-21. Sci Rep 2021; 11:21533. [PMID: 34728715 PMCID: PMC8563764 DOI: 10.1038/s41598-021-00958-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022] Open
Abstract
DNA topoisomerase II (TOP2) is a nuclear protein that resolves DNA topological problems and plays critical roles in multiple nuclear processes. Human cells have two TOP2 proteins, TOP2A and TOP2B, that are localized in both the nucleoplasm and nucleolus. Previously, ATP depletion was shown to augment the nucleolar localization of TOP2B, but the molecular details of subnuclear distributions, particularly of TOP2A, remained to be fully elucidated in relation to the status of cellular ATP. Here, we analyzed the nuclear dynamics of human TOP2A and TOP2B in ATP-depleted cells. Both proteins rapidly translocated from the nucleoplasm to the nucleolus in response to ATP depletion. FRAP analysis demonstrated that they were highly mobile in the nucleoplasm and nucleolus. The nucleolar retention of both proteins was sensitive to the RNA polymerase I inhibitor BMH-21, and the TOP2 proteins in the nucleolus were immediately dispersed into the nucleoplasm by BMH-21. Under ATP-depleted conditions, the TOP2 poison etoposide was less effective, indicating the therapeutic relevance of TOP2 subnuclear distributions. These results give novel insights into the subnuclear dynamics of TOP2 in relation to cellular ATP levels and also provide discussions about its possible mechanisms and biological significance.
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12
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Paulson JR, Hudson DF, Cisneros-Soberanis F, Earnshaw WC. Mitotic chromosomes. Semin Cell Dev Biol 2021; 117:7-29. [PMID: 33836947 PMCID: PMC8406421 DOI: 10.1016/j.semcdb.2021.03.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 01/25/2023]
Abstract
Our understanding of the structure and function of mitotic chromosomes has come a long way since these iconic objects were first recognized more than 140 years ago, though many details remain to be elucidated. In this chapter, we start with the early history of chromosome studies and then describe the path that led to our current understanding of the formation and structure of mitotic chromosomes. We also discuss some of the remaining questions. It is now well established that each mitotic chromatid consists of a central organizing region containing a so-called "chromosome scaffold" from which loops of DNA project radially. Only a few key non-histone proteins and protein complexes are required to form the chromosome: topoisomerase IIα, cohesin, condensin I and condensin II, and the chromokinesin KIF4A. These proteins are concentrated along the axis of the chromatid. Condensins I and II are primarily responsible for shaping the chromosome and the scaffold, and they produce the loops of DNA by an ATP-dependent process known as loop extrusion. Modelling of Hi-C data suggests that condensin II adopts a spiral staircase arrangement with an extruded loop extending out from each step in a roughly helical pattern. Condensin I then forms loops nested within these larger condensin II loops, thereby giving rise to the final compaction of the mitotic chromosome in a process that requires Topo IIα.
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Affiliation(s)
- James R Paulson
- Department of Chemistry, University of Wisconsin Oshkosh, 800 Algoma Boulevard, Oshkosh, WI 54901, USA.
| | - Damien F Hudson
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, VIC 3052, Australia
| | - Fernanda Cisneros-Soberanis
- Wellcome Trust Centre for Cell Biology, ICB, University of Edinburgh, Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, ICB, University of Edinburgh, Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK.
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13
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Chu L, Liang Z, Mukhina M, Fisher J, Vincenten N, Zhang Z, Hutchinson J, Zickler D, Kleckner N. The 3D Topography of Mitotic Chromosomes. Mol Cell 2020; 79:902-916.e6. [PMID: 32768407 DOI: 10.1016/j.molcel.2020.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/16/2020] [Accepted: 07/06/2020] [Indexed: 01/08/2023]
Abstract
A long-standing conundrum is how mitotic chromosomes can compact, as required for clean separation to daughter cells, while maintaining close parallel alignment of sister chromatids. Pursuit of this question, by high resolution 3D fluorescence imaging of living and fixed mammalian cells, has led to three discoveries. First, we show that the structural axes of separated sister chromatids are linked by evenly spaced "mini-axis" bridges. Second, when chromosomes first emerge as discrete units, at prophase, they are organized as co-oriented sister linear loop arrays emanating from a conjoined axis. We show that this same basic organization persists throughout mitosis, without helical coiling. Third, from prophase onward, chromosomes are deformed into sequential arrays of half-helical segments of alternating handedness (perversions), accompanied by correlated kinks. These arrays fluctuate dynamically over <15 s timescales. Together these discoveries redefine the foundation for thinking about the evolution of mitotic chromosomes as they prepare for anaphase segregation.
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Affiliation(s)
- Lingluo Chu
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Zhangyi Liang
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Maria Mukhina
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Jay Fisher
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA; Redbud Labs, Research Triangle, NC 27709, USA
| | - Nadine Vincenten
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Zheng Zhang
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA; CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - John Hutchinson
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Denise Zickler
- University Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif sur Yvette, France
| | - Nancy Kleckner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
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14
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Topoisomerase IIα is essential for maintenance of mitotic chromosome structure. Proc Natl Acad Sci U S A 2020; 117:12131-12142. [PMID: 32414923 DOI: 10.1073/pnas.2001760117] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Topoisomerase IIα (TOP2A) is a core component of mitotic chromosomes and important for establishing mitotic chromosome condensation. The primary roles of TOP2A in mitosis have been difficult to decipher due to its multiple functions across the cell cycle. To more precisely understand the role of TOP2A in mitosis, we used the auxin-inducible degron (AID) system to rapidly degrade the protein at different stages of the human cell cycle. Removal of TOP2A prior to mitosis does not affect prophase timing or the initiation of chromosome condensation. Instead, it prevents chromatin condensation in prometaphase, extends the length of prometaphase, and ultimately causes cells to exit mitosis without chromosome segregation occurring. Surprisingly, we find that removal of TOP2A from cells arrested in prometaphase or metaphase cause dramatic loss of compacted mitotic chromosome structure and conclude that TOP2A is crucial for maintenance of mitotic chromosomes. Treatments with drugs used to poison/inhibit TOP2A function, such as etoposide and ICRF-193, do not phenocopy the effects on chromosome structure of TOP2A degradation by AID. Our data point to a role for TOP2A as a structural chromosome maintenance enzyme locking in condensation states once sufficient compaction is achieved.
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15
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Zhang M, Liang C, Chen Q, Yan H, Xu J, Zhao H, Yuan X, Liu J, Lin S, Lu W, Wang F. Histone H2A phosphorylation recruits topoisomerase IIα to centromeres to safeguard genomic stability. EMBO J 2020; 39:e101863. [PMID: 31769059 PMCID: PMC6996575 DOI: 10.15252/embj.2019101863] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 09/23/2019] [Accepted: 10/29/2019] [Indexed: 01/03/2023] Open
Abstract
Chromosome segregation in mitosis requires the removal of catenation between sister chromatids. Timely decatenation of sister DNAs at mitotic centromeres by topoisomerase IIα (TOP2A) is crucial to maintain genomic stability. The chromatin factors that recruit TOP2A to centromeres during mitosis remain unknown. Here, we show that histone H2A Thr-120 phosphorylation (H2ApT120), a modification generated by the mitotic kinase Bub1, is necessary and sufficient for the centromeric localization of TOP2A. Phosphorylation at residue-120 enhances histone H2A binding to TOP2A in vitro. The C-gate and the extreme C-terminal region are important for H2ApT120-dependent localization of TOP2A at centromeres. Preventing H2ApT120-mediated accumulation of TOP2A at mitotic centromeres interferes with sister chromatid disjunction, as evidenced by increased frequency of anaphase ultra-fine bridges (UFBs) that contain catenated DNA. Tethering TOP2A to centromeres bypasses the requirement for H2ApT120 in suppressing anaphase UFBs. These results demonstrate that H2ApT120 acts as a landmark that recruits TOP2A to mitotic centromeres to decatenate sister DNAs. Our study reveals a fundamental role for histone phosphorylation in resolving centromere DNA entanglements and safeguarding genomic stability during mitosis.
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Affiliation(s)
- Miao Zhang
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Cai Liang
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Qinfu Chen
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Haiyan Yan
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Junfen Xu
- Department of Gynecologic OncologyWomen's HospitalZhejiang University School of MedicineHangzhouZhejiangChina
| | - Hongxia Zhao
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Xueying Yuan
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Jingbo Liu
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Shixian Lin
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Weiguo Lu
- Department of Gynecologic OncologyWomen's HospitalZhejiang University School of MedicineHangzhouZhejiangChina
- Women's Reproductive Health Key Research Laboratory of Zhejiang ProvinceWomen's HospitalZhejiang University School of MedicineHangzhouZhejiangChina
| | - Fangwei Wang
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
- Department of Gynecologic OncologyWomen's HospitalZhejiang University School of MedicineHangzhouZhejiangChina
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16
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Antoniou-Kourounioti M, Mimmack ML, Porter ACG, Farr CJ. The Impact of the C-Terminal Region on the Interaction of Topoisomerase II Alpha with Mitotic Chromatin. Int J Mol Sci 2019; 20:ijms20051238. [PMID: 30871006 PMCID: PMC6429393 DOI: 10.3390/ijms20051238] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 03/04/2019] [Accepted: 03/08/2019] [Indexed: 02/06/2023] Open
Abstract
Type II topoisomerase enzymes are essential for resolving DNA topology problems arising through various aspects of DNA metabolism. In vertebrates two isoforms are present, one of which (TOP2A) accumulates on chromatin during mitosis. Moreover, TOP2A targets the mitotic centromere during prophase, persisting there until anaphase onset. It is the catalytically-dispensable C-terminal domain of TOP2 that is crucial in determining this isoform-specific behaviour. In this study we show that, in addition to the recently identified chromatin tether domain, several other features of the alpha-C-Terminal Domain (CTD). influence the mitotic localisation of TOP2A. Lysine 1240 is a major SUMOylation target in cycling human cells and the efficiency of this modification appears to be influenced by T1244 and S1247 phosphorylation. Replacement of K1240 by arginine results in fewer cells displaying centromeric TOP2A accumulation during prometaphase-metaphase. The same phenotype is displayed by cells expressing TOP2A in which either of the mitotic phosphorylation sites S1213 or S1247 has been substituted by alanine. Conversely, constitutive modification of TOP2A by fusion to SUMO2 exerts the opposite effect. FRAP analysis of protein mobility indicates that post-translational modification of TOP2A can influence the enzyme's residence time on mitotic chromatin, as well as its subcellular localisation.
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Affiliation(s)
- Melissa Antoniou-Kourounioti
- Department of Genetics, University of Cambridge, Downing St, Cambridge CB2 3EH, UK.
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
| | - Michael L Mimmack
- Department of Genetics, University of Cambridge, Downing St, Cambridge CB2 3EH, UK.
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK.
| | - Andrew C G Porter
- Centre for Haematology, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Rd, London W12 0NN, UK.
| | - Christine J Farr
- Department of Genetics, University of Cambridge, Downing St, Cambridge CB2 3EH, UK.
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17
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Morotomi-Yano K, Saito S, Adachi N, Yano KI. Dynamic behavior of DNA topoisomerase IIβ in response to DNA double-strand breaks. Sci Rep 2018; 8:10344. [PMID: 29985428 PMCID: PMC6037730 DOI: 10.1038/s41598-018-28690-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 06/27/2018] [Indexed: 12/11/2022] Open
Abstract
DNA topoisomerase II (Topo II) is crucial for resolving topological problems of DNA and plays important roles in various cellular processes, such as replication, transcription, and chromosome segregation. Although DNA topology problems may also occur during DNA repair, the possible involvement of Topo II in this process remains to be fully investigated. Here, we show the dynamic behavior of human Topo IIβ in response to DNA double-strand breaks (DSBs), which is the most harmful form of DNA damage. Live cell imaging coupled with site-directed DSB induction by laser microirradiation demonstrated rapid recruitment of EGFP-tagged Topo IIβ to the DSB site. Detergent extraction followed by immunofluorescence showed the tight association of endogenous Topo IIβ with DSB sites. Photobleaching analysis revealed that Topo IIβ is highly mobile in the nucleus. The Topo II catalytic inhibitors ICRF-187 and ICRF-193 reduced the Topo IIβ mobility and thereby prevented Topo IIβ recruitment to DSBs. Furthermore, Topo IIβ knockout cells exhibited increased sensitivity to bleomycin and decreased DSB repair mediated by homologous recombination (HR), implicating the role of Topo IIβ in HR-mediated DSB repair. Taken together, these results highlight a novel aspect of Topo IIβ functions in the cellular response to DSBs.
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Affiliation(s)
- Keiko Morotomi-Yano
- Department of Bioelectrics, Institute of Pulsed Power Science, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Shinta Saito
- Department of Life and Environmental System Science, Graduate School of Nanobioscience, Yokohama City University, Yokohama, 236-0027, Japan
| | - Noritaka Adachi
- Department of Life and Environmental System Science, Graduate School of Nanobioscience, Yokohama City University, Yokohama, 236-0027, Japan.,Advanced Medical Research Center, Yokohama City University, Yokohama, 236-0004, Japan
| | - Ken-Ichi Yano
- Department of Bioelectrics, Institute of Pulsed Power Science, Kumamoto University, Kumamoto, 860-8555, Japan.
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18
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Mills WE, Spence JM, Fukagawa T, Farr CJ. Site-Specific Cleavage by Topoisomerase 2: A Mark of the Core Centromere. Int J Mol Sci 2018; 19:E534. [PMID: 29439406 PMCID: PMC5855756 DOI: 10.3390/ijms19020534] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/06/2018] [Accepted: 02/07/2018] [Indexed: 12/12/2022] Open
Abstract
In addition to its roles in transcription and replication, topoisomerase 2 (topo 2) is crucial in shaping mitotic chromosomes and in ensuring the orderly separation of sister chromatids. As well as its recruitment throughout the length of the mitotic chromosome, topo 2 accumulates at the primary constriction. Here, following cohesin release, the enzymatic activity of topo 2 acts to remove residual sister catenations. Intriguingly, topo 2 does not bind and cleave all sites in the genome equally; one preferred site of cleavage is within the core centromere. Discrete topo 2-centromeric cleavage sites have been identified in α-satellite DNA arrays of active human centromeres and in the centromere regions of some protozoans. In this study, we show that topo 2 cleavage sites are also a feature of the centromere in Schizosaccharomyces pombe, the metazoan Drosophila melanogaster and in another vertebrate species, Gallus gallus (chicken). In vertebrates, we show that this site-specific cleavage is diminished by depletion of CENP-I, an essential constitutive centromere protein. The presence, within the core centromere of a wide range of eukaryotes, of precise sites hypersensitive to topo 2 cleavage suggests that these mark a fundamental and conserved aspect of this functional domain, such as a non-canonical secondary structure.
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Affiliation(s)
- Walter E Mills
- Department of Genetics, University of Cambridge, Downing St, Cambridge CB2 3EH, UK.
| | - Jennifer M Spence
- Department of Genetics, University of Cambridge, Downing St, Cambridge CB2 3EH, UK.
| | - Tatsuo Fukagawa
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan.
| | - Christine J Farr
- Department of Genetics, University of Cambridge, Downing St, Cambridge CB2 3EH, UK.
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19
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Ilicheva N, Podgornaya O, Bogolyubov D, Pochukalina G. The karyosphere capsule in Rana temporaria oocytes contains structural and DNA-binding proteins. Nucleus 2018; 9:516-529. [PMID: 30272509 PMCID: PMC6244735 DOI: 10.1080/19491034.2018.1530935] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/21/2018] [Accepted: 09/26/2018] [Indexed: 12/14/2022] Open
Abstract
During the last stages of oogenesis, oocyte chromosomes condense and come close together, forming the so-called karyosphere. Karyosphere formation is accompanied by an essential decrease in transcriptional activity. In the grass frog Rana temporaria, the karyosphere is surrounded by an extrachromosomal capsule that separates the chromosomes from the rest of the nucleoplasm. The karyosphere capsule (KC) of R. temporaria has been investigated in detail at the ultrastructural level, but its protein composition remained largely unknown. We demonstrate here that nuclear actin, especially F-actin, as well as lamins A/C and B are the most abundant proteins of the KC. Key proteins of nuclear pore complexes, such as Nup93 and Nup35, are also detectable in the KC. New antibodies recognizing the telomere-binding protein TRF2 allowed us to localize TRF2 in nuclear speckles. We also found that the R. temporaria KC contains some proteins involved in chromatin remodeling, including topoisomerase II and ATRX. Thus, we believe that KC isolates the chromosomes from the rest of the nucleoplasm during the final period of oocyte growth (late diplotene) and represents a specialized oocyte nuclear compartment to store a variety of factors involved in nuclear metabolism that can be used in future early development. Abbreviations: BrUTP: 5-bromouridine 5'-triphosphate; CytD: cytochalasin D; IGCs: interchromatin granule clasters; IgG: immunoglobulin G; KC: karyosphere capsule; Mw: molecular weight; NE: nuclear envelope; PBS: phosphate buffered saline; SDS-PAGE: sodium dodecyl sulfate polyacrylamide gel electrophoresis; Topo II: topoisomerase II.
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Affiliation(s)
- Nadya Ilicheva
- Laboratory of Cell Morphology, Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia
| | - Olga Podgornaya
- Laboratory of Cell Morphology, Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia
- Department of Cytology and Histology, Faculty of Biology, Saint Petersburg State University, St. Petersburg, Russia
- Laboratory of Biomedical Cell Technology, School of Biomedicine, Far Eastern Federal University, Vladivostok, Russia
| | - Dmitry Bogolyubov
- Laboratory of Cell Morphology, Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia
| | - Galina Pochukalina
- Laboratory of Cell Morphology, Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia
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20
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Hindriksen S, Lens SMA, Hadders MA. The Ins and Outs of Aurora B Inner Centromere Localization. Front Cell Dev Biol 2017; 5:112. [PMID: 29312936 PMCID: PMC5743930 DOI: 10.3389/fcell.2017.00112] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/04/2017] [Indexed: 01/12/2023] Open
Abstract
Error-free chromosome segregation is essential for the maintenance of genomic integrity during cell division. Aurora B, the enzymatic subunit of the Chromosomal Passenger Complex (CPC), plays a crucial role in this process. In early mitosis Aurora B localizes predominantly to the inner centromere, a specialized region of chromatin that lies at the crossroads between the inter-kinetochore and inter-sister chromatid axes. Two evolutionarily conserved histone kinases, Haspin and Bub1, control the positioning of the CPC at the inner centromere and this location is thought to be crucial for the CPC to function. However, recent studies sketch a subtler picture, in which not all functions of the CPC require strict confinement to the inner centromere. In this review we discuss the molecular pathways that direct Aurora B to the inner centromere and deliberate if and why this specific localization is important for Aurora B function.
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Affiliation(s)
- Sanne Hindriksen
- Oncode Institute, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Susanne M A Lens
- Oncode Institute, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Michael A Hadders
- Oncode Institute, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
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21
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Piskadlo E, Oliveira RA. A Topology-Centric View on Mitotic Chromosome Architecture. Int J Mol Sci 2017; 18:E2751. [PMID: 29258269 PMCID: PMC5751350 DOI: 10.3390/ijms18122751] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 02/04/2023] Open
Abstract
Mitotic chromosomes are long-known structures, but their internal organization and the exact process by which they are assembled are still a great mystery in biology. Topoisomerase II is crucial for various aspects of mitotic chromosome organization. The unique ability of this enzyme to untangle topologically intertwined DNA molecules (catenations) is of utmost importance for the resolution of sister chromatid intertwines. Although still controversial, topoisomerase II has also been proposed to directly contribute to chromosome compaction, possibly by promoting chromosome self-entanglements. These two functions raise a strong directionality issue towards topoisomerase II reactions that are able to disentangle sister DNA molecules (in trans) while compacting the same DNA molecule (in cis). Here, we review the current knowledge on topoisomerase II role specifically during mitosis, and the mechanisms that directly or indirectly regulate its activity to ensure faithful chromosome segregation. In particular, we discuss how the activity or directionality of this enzyme could be regulated by the SMC (structural maintenance of chromosomes) complexes, predominantly cohesin and condensin, throughout mitosis.
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Affiliation(s)
- Ewa Piskadlo
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
| | - Raquel A Oliveira
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
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22
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Clarke DJ, Azuma Y. Non-Catalytic Roles of the Topoisomerase IIα C-Terminal Domain. Int J Mol Sci 2017; 18:ijms18112438. [PMID: 29149026 PMCID: PMC5713405 DOI: 10.3390/ijms18112438] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/10/2017] [Accepted: 11/14/2017] [Indexed: 12/26/2022] Open
Abstract
DNA Topoisomerase IIα (Topo IIα) is a ubiquitous enzyme in eukaryotes that performs the strand passage reaction where a double helix of DNA is passed through a second double helix. This unique reaction is critical for numerous cellular processes. However, the enzyme also possesses a C-terminal domain (CTD) that is largely dispensable for the strand passage reaction but is nevertheless important for the fidelity of cell division. Recent studies have expanded our understanding of the roles of the Topo IIα CTD, in particular in mitotic mechanisms where the CTD is modified by Small Ubiquitin-like Modifier (SUMO), which in turn provides binding sites for key regulators of mitosis.
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Affiliation(s)
- Duncan J Clarke
- Department of Genetics, Cell Biology & Development, University of Minnesota, 420 Washington Ave SE, Minneapolis, MN 55455, USA.
| | - Yoshiaki Azuma
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA.
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23
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Festuccia N, Gonzalez I, Owens N, Navarro P. Mitotic bookmarking in development and stem cells. Development 2017; 144:3633-3645. [DOI: 10.1242/dev.146522] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The changes imposed on the nucleus, chromatin and its regulators during mitosis lead to the dismantlement of most gene regulatory processes. However, an increasing number of transcriptional regulators are being identified as capable of binding their genomic targets during mitosis. These so-called ‘mitotic bookmarking factors’ encompass transcription factors and chromatin modifiers that are believed to convey gene regulatory information from mother to daughter cells. In this Primer, we review mitotic bookmarking processes in development and stem cells and discuss the interest and potential importance of this concept with regard to epigenetic regulation and cell fate transitions involving cellular proliferation.
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Affiliation(s)
- Nicola Festuccia
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Inma Gonzalez
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Nick Owens
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Pablo Navarro
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
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24
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Wu KZL, Wang GN, Fitzgerald J, Quachthithu H, Rainey MD, Cattaneo A, Bachi A, Santocanale C. DDK dependent regulation of TOP2A at centromeres revealed by a chemical genetics approach. Nucleic Acids Res 2016; 44:8786-8798. [PMID: 27407105 PMCID: PMC5062981 DOI: 10.1093/nar/gkw626] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 07/02/2016] [Indexed: 11/14/2022] Open
Abstract
In eukaryotic cells the CDC7/DBF4 kinase, also known as DBF4-dependent kinase (DDK), is required for the firing of DNA replication origins. CDC7 is also involved in replication stress responses and its depletion sensitises cells to drugs that affect fork progression, including Topoisomerase 2 poisons. Although CDC7 is an important regulator of cell division, relatively few substrates and bona-fide CDC7 phosphorylation sites have been identified to date in human cells. In this study, we have generated an active recombinant CDC7/DBF4 kinase that can utilize bulky ATP analogues. By performing in vitro kinase assays using benzyl-thio-ATP, we have identified TOP2A as a primary CDC7 substrate in nuclear extracts, and serine 1213 and serine 1525 as in vitro phosphorylation sites. We show that CDC7/DBF4 and TOP2A interact in cells, that this interaction mainly occurs early in S-phase, and that it is compromised after treatment with CDC7 inhibitors. We further provide evidence that human DBF4 localises at centromeres, to which TOP2A is progressively recruited during S-phase. Importantly, we found that CDC7/DBF4 down-regulation, as well S1213A/S1525A TOP2A mutations can advance the timing of centromeric TOP2A recruitment in S-phase. Our results indicate that TOP2A is a novel DDK target and have important implications for centromere biology.
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Affiliation(s)
- Kevin Z L Wu
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Guan-Nan Wang
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Jennifer Fitzgerald
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Huong Quachthithu
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Michael D Rainey
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Angela Cattaneo
- IFOM-FIRC Institute of Molecular Oncology, Milan 20139, Italy
| | - Angela Bachi
- IFOM-FIRC Institute of Molecular Oncology, Milan 20139, Italy
| | - Corrado Santocanale
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Ireland
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25
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Pochukalina GN, Ilicheva NV, Podgornaya OI, Voronin AP. Nucleolus-like body of mouse oocytes contains lamin A and B and TRF2 but not actin and topo II. Mol Cytogenet 2016; 9:50. [PMID: 27347007 PMCID: PMC4921027 DOI: 10.1186/s13039-016-0259-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 06/18/2016] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND During the final stages of oocyte development, all chromosomes join in a limited nuclear volume for the final formation of a single complex chromatin structure - the karyosphere. In the majority of mammalian species, the chromosomes surround a round protein/fibrillar body known as the central body, or nucleolus-like body (NLB). Nothing seems to unite the inner portion of the karyosphere with the nucleolus except position at its remnants. Nevertheless, in this study we will use term NLB as the conventional one for karyosphere with the central body. At the morphological level, NLBs consist of tightly-packed fibres of 6-10 nm. The biochemical structure of this dense, compact NLB fibre centre remains uncertain. RESULTS The aim of this study was to determine which proteins represent the NLB components at final stages of karyosphere formation in mouse oogenesis. To determine this, three antibodies (ABs) have been examined against different actin epitopes. Examination of both ABs against the actin N-end provided similar results: spots inside the nucleus. Double staining with AB against SC35 and actin revealed the colocalization of these proteins in IGCs (interchromatin granule clusters/nuclear speckles/SC35 domains). In contrast, examination of polyclonal AB against peptide at the C-end reveals a different result: actin is localized exclusively in connection with the chromatin. Surprisingly, no forms of actin or topoisomerase II are present as components of the NLB. It was discovered that: (1) lamin B is an NLB component from the beginning of NLB formation, and a major portion of it resides in the NLB at the end of oocyte development; (2) lamin A undergoes rapid movement into the NLB, and a majority of it remains in the NLB; (3) the telomere-binding protein TRF2 resides in the IGCs/nuclear speckles until the end of oocyte development, when significant part of it transfers to the NLB. CONCLUSIONS NLBs do not contain actin or topo II. Lamin B is involved from the beginning of NLB formation. Both Lamin A and TRF2 exhibit rapid movement to the NLB at the end of oogenesis. This dynamic distribution of proteins may reflect the NLB's role in future chromatin organization post-fertilisation.
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Affiliation(s)
| | - Nadya V. Ilicheva
- />Institute of Cytology, Russian Academy of Sciences, St Petersburg, 194064 Russia
| | - Olga I. Podgornaya
- />Institute of Cytology, Russian Academy of Sciences, St Petersburg, 194064 Russia
- />Saint Petersburg State University, St Petersburg, 199034 Russia
- />Far Eastern Federal University, Vladivostok, 690950 Russia
| | - Alexey P. Voronin
- />Institute of Cytology, Russian Academy of Sciences, St Petersburg, 194064 Russia
- />Saint Petersburg State University, St Petersburg, 199034 Russia
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26
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Daban JR. Stacked thin layers of metaphase chromatin explain the geometry of chromosome rearrangements and banding. Sci Rep 2015; 5:14891. [PMID: 26446309 PMCID: PMC4597206 DOI: 10.1038/srep14891] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 08/21/2015] [Indexed: 01/02/2023] Open
Abstract
The three-dimensional organization of tightly condensed chromatin within metaphase chromosomes has been one of the most challenging problems in structural biology since the discovery of the nucleosome. This study shows that chromosome images obtained from typical banded karyotypes and from different multicolour cytogenetic analyses can be used to gain information about the internal structure of chromosomes. Chromatin bands and the connection surfaces in sister chromatid exchanges and in cancer translocations are planar and orthogonal to the chromosome axis. Chromosome stretching produces band splitting and even the thinnest bands are orthogonal and well defined, indicating that short stretches of DNA can occupy completely the chromosome cross-section. These observations impose strong physical constraints on models that attempt to explain chromatin folding in chromosomes. The thin-plate model, which consists of many stacked layers of planar chromatin perpendicular to the chromosome axis, is compatible with the observed orientation of bands, with the existence of thin bands, and with band splitting; it is also compatible with the orthogonal orientation and planar geometry of the connection surfaces in chromosome rearrangements. The results obtained provide a consistent interpretation of the chromosome structural properties that are used in clinical cytogenetics for the diagnosis of hereditary diseases and cancers.
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Affiliation(s)
- Joan-Ramon Daban
- Departament de Bioquímica i Biologia Molecular, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193-Bellaterra, Spain
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27
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Liang Z, Zickler D, Prentiss M, Chang FS, Witz G, Maeshima K, Kleckner N. Chromosomes Progress to Metaphase in Multiple Discrete Steps via Global Compaction/Expansion Cycles. Cell 2015; 161:1124-1137. [PMID: 26000485 PMCID: PMC4448932 DOI: 10.1016/j.cell.2015.04.030] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Revised: 03/20/2015] [Accepted: 04/09/2015] [Indexed: 01/29/2023]
Abstract
Mammalian mitotic chromosome morphogenesis was analyzed by 4D live-cell and snapshot deconvolution fluorescence imaging. Prophase chromosomes, whose organization was previously unknown, are revealed to comprise co-oriented sister linear loop arrays displayed along a single, peripheral, regularly kinked topoisomerase II/cohesin/condensin II axis. Thereafter, rather than smooth, progressive compaction as generally envisioned, progression to metaphase is a discontinuous process involving chromosome expansion as well as compaction. At late prophase, dependent on topoisomerase II and with concomitant cohesin release, chromosomes expand, axes split and straighten, and chromatin loops transit to a radial disposition around now-central axes. Finally, chromosomes globally compact, giving the metaphase state. These patterns are consistent with the hypothesis that the molecular events of chromosome morphogenesis are governed by accumulation and release of chromosome stress, created by chromatin compaction and expansion. Chromosome state could evolve analogously throughout the cell cycle.
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Affiliation(s)
- Zhangyi Liang
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Denise Zickler
- Institut de Génétique and Microbiologie, Université Paris-sud, 91405 Orsay Cedex, France
| | - Mara Prentiss
- Deparment of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Frederick S Chang
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Guillaume Witz
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Kazuhiro Maeshima
- National Institute of Genetics and Graduate University for Advanced Studies (Sokendai), Mishima, Shizuoka 411-8540, Japan
| | - Nancy Kleckner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
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28
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Abstract
How eukaryotic genomes are packaged into compact cylindrical chromosomes in preparation for cell divisions has remained one of the major unsolved questions of cell biology. Novel approaches to study the topology of DNA helices inside the nuclei of intact cells, paired with computational modeling and precise biomechanical measurements of isolated chromosomes, have advanced our understanding of mitotic chromosome architecture. In this Review Essay, we discuss - in light of these recent insights - the role of chromatin architecture and the functions and possible mechanisms of SMC protein complexes and other molecular machines in the formation of mitotic chromosomes. Based on the information available, we propose a stepwise model of mitotic chromosome condensation that envisions the sequential generation of intra-chromosomal linkages by condensin complexes in the context of cohesin-mediated inter-chromosomal linkages, assisted by topoisomerase II. The described scenario results in rod-shaped metaphase chromosomes ready for their segregation to the cell poles.
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Affiliation(s)
- Marc Kschonsak
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
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29
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Magalska A, Schellhaus A, Moreno-Andrés D, Zanini F, Schooley A, Sachdev R, Schwarz H, Madlung J, Antonin W. RuvB-like ATPases Function in Chromatin Decondensation at the End of Mitosis. Dev Cell 2014; 31:305-318. [DOI: 10.1016/j.devcel.2014.09.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/22/2014] [Accepted: 09/03/2014] [Indexed: 10/24/2022]
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30
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Mengoli V, Bucciarelli E, Lattao R, Piergentili R, Gatti M, Bonaccorsi S. The analysis of mutant alleles of different strength reveals multiple functions of topoisomerase 2 in regulation of Drosophila chromosome structure. PLoS Genet 2014; 10:e1004739. [PMID: 25340516 PMCID: PMC4207652 DOI: 10.1371/journal.pgen.1004739] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 09/08/2014] [Indexed: 12/14/2022] Open
Abstract
Topoisomerase II is a major component of mitotic chromosomes but its role in the assembly and structural maintenance of chromosomes is rather controversial, as different chromosomal phenotypes have been observed in various organisms and in different studies on the same organism. In contrast to vertebrates that harbor two partially redundant Topo II isoforms, Drosophila and yeasts have a single Topo II enzyme. In addition, fly chromosomes, unlike those of yeast, are morphologically comparable to vertebrate chromosomes. Thus, Drosophila is a highly suitable system to address the role of Topo II in the assembly and structural maintenance of chromosomes. Here we show that modulation of Top2 function in living flies by means of mutant alleles of different strength and in vivo RNAi results in multiple cytological phenotypes. In weak Top2 mutants, meiotic chromosomes of males exhibit strong morphological abnormalities and dramatic segregation defects, while mitotic chromosomes of larval brain cells are not affected. In mutants of moderate strength, mitotic chromosome organization is normal, but anaphases display frequent chromatin bridges that result in chromosome breaks and rearrangements involving specific regions of the Y chromosome and 3L heterochromatin. Severe Top2 depletion resulted in many aneuploid and polyploid mitotic metaphases with poorly condensed heterochromatin and broken chromosomes. Finally, in the almost complete absence of Top2, mitosis in larval brains was virtually suppressed and in the rare mitotic figures observed chromosome morphology was disrupted. These results indicate that different residual levels of Top2 in mutant cells can result in different chromosomal phenotypes, and that the effect of a strong Top2 depletion can mask the effects of milder Top2 reductions. Thus, our results suggest that the previously observed discrepancies in the chromosomal phenotypes elicited by Topo II downregulation in vertebrates might depend on slight differences in Topo II concentration and/or activity.
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Affiliation(s)
- Valentina Mengoli
- Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari (IBPM) del CNR, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza, Università di Roma, Roma, Italy
| | - Elisabetta Bucciarelli
- Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari (IBPM) del CNR, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza, Università di Roma, Roma, Italy
| | - Ramona Lattao
- Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari (IBPM) del CNR, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza, Università di Roma, Roma, Italy
| | - Roberto Piergentili
- Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari (IBPM) del CNR, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza, Università di Roma, Roma, Italy
| | - Maurizio Gatti
- Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari (IBPM) del CNR, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza, Università di Roma, Roma, Italy
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russia
| | - Silvia Bonaccorsi
- Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari (IBPM) del CNR, Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza, Università di Roma, Roma, Italy
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31
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Eguren M, Álvarez-Fernández M, García F, López-Contreras AJ, Fujimitsu K, Yaguchi H, Luque-García JL, Fernández-Capetillo O, Muñoz J, Yamano H, Malumbres M. A synthetic lethal interaction between APC/C and topoisomerase poisons uncovered by proteomic screens. Cell Rep 2014; 6:670-83. [PMID: 24508461 DOI: 10.1016/j.celrep.2014.01.017] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 12/30/2013] [Accepted: 01/14/2014] [Indexed: 11/24/2022] Open
Abstract
The Anaphase-promoting complex/cyclosome (APC/C) cofactor Cdh1 modulates cell proliferation by targeting multiple cell-cycle regulators for ubiquitin-dependent degradation. Lack of Cdh1 results in structural and numerical chromosome aberrations, a hallmark of genomic instability. By using a proteomic approach in Cdh1-null cells and mouse tissues, we have identified kinesin Eg5 and topoisomerase 2α as Cdh1 targets involved in the maintenance of genomic stability. These proteins are ubiquitinated and degraded through specific KEN and D boxes in a Cdh1-dependent manner. Whereas Cdh1-null cells display partial resistance to Eg5 inhibitors such as monastrol, lack of Cdh1 results in a dramatic sensitivity to Top2α poisons as a consequence of increased levels of trapped Top2α-DNA complexes. Chemical inhibition of the APC/C in cancer cells results in increased sensitivity to Top2α poisons. This work identifies in vivo targets of the mammalian APC/C-Cdh1 complex and reveals synthetic lethal interactions of relevance in anticancer treatments.
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Affiliation(s)
- Manuel Eguren
- Cell Division and Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain
| | - Mónica Álvarez-Fernández
- Cell Division and Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain
| | - Fernando García
- Proteomics Unit, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain
| | | | - Kazuyuki Fujimitsu
- Cell Cycle Control Group, University College London Cancer Institute, London WC1E 6BT, UK
| | - Hiroko Yaguchi
- Cell Cycle Control Group, University College London Cancer Institute, London WC1E 6BT, UK
| | - José Luis Luque-García
- Department of Analytical Chemistry, Complutense University of Madrid, Madrid 28015, Spain
| | | | - Javier Muñoz
- Proteomics Unit, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain
| | - Hiroyuki Yamano
- Cell Cycle Control Group, University College London Cancer Institute, London WC1E 6BT, UK
| | - Marcos Malumbres
- Cell Division and Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain.
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32
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Farr CJ, Antoniou-Kourounioti M, Mimmack ML, Volkov A, Porter ACG. The α isoform of topoisomerase II is required for hypercompaction of mitotic chromosomes in human cells. Nucleic Acids Res 2014; 42:4414-26. [PMID: 24476913 PMCID: PMC3985649 DOI: 10.1093/nar/gku076] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
As proliferating cells transit from interphase into M-phase, chromatin undergoes extensive reorganization, and topoisomerase (topo) IIα, the major isoform of this enzyme present in cycling vertebrate cells, plays a key role in this process. In this study, a human cell line conditional null mutant for topo IIα and a derivative expressing an auxin-inducible degron (AID)-tagged version of the protein have been used to distinguish real mitotic chromosome functions of topo IIα from its more general role in DNA metabolism and to investigate whether topo IIβ makes any contribution to mitotic chromosome formation. We show that topo IIβ does contribute, with endogenous levels being sufficient for the initial stages of axial shortening. However, a significant effect of topo IIα depletion, seen with or without the co-depletion of topo IIβ, is the failure of chromosomes to hypercompact when delayed in M-phase. This requires much higher levels of topo II protein and is impaired by drugs or mutations that affect enzyme activity. A prolonged delay at the G2/M border results in hyperefficient axial shortening, a process that is topo IIα-dependent. Rapid depletion of topo IIα has allowed us to show that its function during late G2 and M-phase is truly required for shaping mitotic chromosomes.
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Affiliation(s)
- Christine J Farr
- Department of Genetics, University of Cambridge, Downing St, Cambridge CB2 3EH, UK and Centre for Haematology, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Rd, London W12 0NN, UK
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33
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Lane AB, Giménez-Abián JF, Clarke DJ. A novel chromatin tether domain controls topoisomerase IIα dynamics and mitotic chromosome formation. ACTA ACUST UNITED AC 2014; 203:471-86. [PMID: 24217621 PMCID: PMC3824022 DOI: 10.1083/jcb.201303045] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The dynamics of topoisomerase IIα binding to DNA and histones are important for successful mitosis and are regulated by a novel chromatin tether (ChT) domain in topoisomerase IIα. DNA topoisomerase IIα (Topo IIα) is the target of an important class of anticancer drugs, but tumor cells can become resistant by reducing the association of the enzyme with chromosomes. Here we describe a critical mechanism of chromatin recruitment and exchange that relies on a novel chromatin tether (ChT) domain and mediates interaction with histone H3 and DNA. We show that the ChT domain controls the residence time of Topo IIα on chromatin in mitosis and is necessary for the formation of mitotic chromosomes. Our data suggest that the dynamics of Topo IIα on chromosomes are important for successful mitosis and implicate histone tail posttranslational modifications in regulating Topo IIα.
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Affiliation(s)
- Andrew B Lane
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455
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34
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Furniss KL, Tsai HJ, Byl JAW, Lane AB, Vas AC, Hsu WS, Osheroff N, Clarke DJ. Direct monitoring of the strand passage reaction of DNA topoisomerase II triggers checkpoint activation. PLoS Genet 2013; 9:e1003832. [PMID: 24098144 PMCID: PMC3789831 DOI: 10.1371/journal.pgen.1003832] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 08/10/2013] [Indexed: 02/04/2023] Open
Abstract
By necessity, the ancient activity of type II topoisomerases co-evolved with the double-helical structure of DNA, at least in organisms with circular genomes. In humans, the strand passage reaction of DNA topoisomerase II (Topo II) is the target of several major classes of cancer drugs which both poison Topo II and activate cell cycle checkpoint controls. It is important to know the cellular effects of molecules that target Topo II, but the mechanisms of checkpoint activation that respond to Topo II dysfunction are not well understood. Here, we provide evidence that a checkpoint mechanism monitors the strand passage reaction of Topo II. In contrast, cells do not become checkpoint arrested in the presence of the aberrant DNA topologies, such as hyper-catenation, that arise in the absence of Topo II activity. An overall reduction in Topo II activity (i.e. slow strand passage cycles) does not activate the checkpoint, but specific defects in the T-segment transit step of the strand passage reaction do induce a cell cycle delay. Furthermore, the cell cycle delay depends on the divergent and catalytically inert C-terminal region of Topo II, indicating that transmission of a checkpoint signal may occur via the C-terminus. Other, well characterized, mitotic checkpoints detect DNA lesions or monitor unattached kinetochores; these defects arise via failures in a variety of cell processes. In contrast, we have described the first example of a distinct category of checkpoint mechanism that monitors the catalytic cycle of a single specific enzyme in order to determine when chromosome segregation can proceed faithfully.
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Affiliation(s)
- Katherine L. Furniss
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Hung-Ji Tsai
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Jo Ann W. Byl
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Andrew B. Lane
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Amit C. Vas
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Wei-Shan Hsu
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Neil Osheroff
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Duncan J. Clarke
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, Minnesota, United States of America
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35
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Chen SH, Chan NL, Hsieh TS. New mechanistic and functional insights into DNA topoisomerases. Annu Rev Biochem 2013; 82:139-70. [PMID: 23495937 DOI: 10.1146/annurev-biochem-061809-100002] [Citation(s) in RCA: 257] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DNA topoisomerases are nature's tools for resolving the unique problems of DNA entanglement that occur owing to unwinding and rewinding of the DNA helix during replication, transcription, recombination, repair, and chromatin remodeling. These enzymes perform topological transformations by providing a transient DNA break, formed by a covalent adduct with the enzyme, through which strand passage can occur. The active site tyrosine is responsible for initiating two transesterifications to cleave and then religate the DNA backbone. The cleavage reaction intermediate is exploited by cytotoxic agents, which have important applications as antibiotics and anticancer drugs. The reactions mediated by these enzymes can also be regulated by their binding partners; one example is a DNA helicase capable of modulating the directionality of strand passage, enabling important functions like reannealing denatured DNA and resolving recombination intermediates. In this review, we cover recent advances in mechanistic insights into topoisomerases and their various cellular functions.
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Affiliation(s)
- Stefanie Hartman Chen
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.
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36
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Wan J, Subramonian D, Zhang XD. SUMOylation in control of accurate chromosome segregation during mitosis. Curr Protein Pept Sci 2013; 13:467-81. [PMID: 22812528 PMCID: PMC3474960 DOI: 10.2174/138920312802430563] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Revised: 02/26/2012] [Accepted: 06/11/2012] [Indexed: 12/15/2022]
Abstract
Posttranslational protein modification by small ubiquitin-related modifier (SUMO) has emerged as an important regulatory mechanism for chromosome segregation during mitosis. This review focuses on how SUMOylation regulates the centromere and kinetochore activities to achieve accurate chromosome segregation during mitosis. Kinetochores are assembled on the specialized chromatin domains called centromeres and serve as the sites for attaching spindle microtubule to segregate sister chromatids to daughter cells. Many proteins associated with mitotic centromeres and kinetochores have been recently found to be modified by SUMO. Although we are still at the early stage of elucidating how SUMOylation controls chromosome segregation during mitosis, a substantial progress has been achieved over the past decade. Furthermore, a major theme that has emerged from the recent studies of SUMOylation in mitosis is that both SUMO conjugation and deconjugation are critical for kinetochore assembly and disassembly. Lastly, we propose a model that SUMOylation coordinates multiple centromere and kinetochore activities to ensure accurate chromosome segregation.
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Affiliation(s)
- Jun Wan
- Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA
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37
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Vagnarelli P. Chromatin reorganization through mitosis. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2013; 90:179-224. [PMID: 23582205 DOI: 10.1016/b978-0-12-410523-2.00006-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Chromosome condensation is one of the major chromatin-remodeling events that occur during cell division. The changes in chromatin compaction and higher-order structure organization are essential requisites for ensuring a faithful transmission of the replicated genome to daughter cells. Although the observation of mitotic chromosome condensation has fascinated Scientists for a century, we are still far away from understanding how the process works from a molecular point of view. In this chapter, I will analyze our current understanding of chromatin condensation during mitosis with particular attention to the major molecular players that trigger and maintain this particular chromatin conformation. However, within the chromosome, not all regions of the chromatin are organized in the same manner. I will address separately the structure and functions of particular chromatin domains such as the centromere. Finally, the transition of the chromatin through mitosis represents just an interlude for gene expression between two cell cycles. How the transcriptional information that governs cell linage identity is transmitted from mother to daughter represents a big and interesting question. I will present how cells take care of the aspect ensuring that mitotic chromosome condensation and the block of transcription does not wipe out the cell identity.
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Affiliation(s)
- Paola Vagnarelli
- Heinz Wolff Building, Brunel University, Uxbridge, United Kingdom.
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38
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Local nucleosome dynamics facilitate chromatin accessibility in living mammalian cells. Cell Rep 2012; 2:1645-56. [PMID: 23246002 DOI: 10.1016/j.celrep.2012.11.008] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 09/15/2012] [Accepted: 11/09/2012] [Indexed: 12/19/2022] Open
Abstract
Genome information, which is three-dimensionally organized within cells as chromatin, is searched and read by various proteins for diverse cell functions. Although how the protein factors find their targets remains unclear, the dynamic and flexible nature of chromatin is likely crucial. Using a combined approach of fluorescence correlation spectroscopy, single-nucleosome imaging, and Monte Carlo computer simulations, we demonstrate local chromatin dynamics in living mammalian cells. We show that similar to interphase chromatin, dense mitotic chromosomes also have considerable chromatin accessibility. For both interphase and mitotic chromatin, we observed local fluctuation of individual nucleosomes (~50 nm movement/30 ms), which is caused by confined Brownian motion. Inhibition of these local dynamics by crosslinking impaired accessibility in the dense chromatin regions. Our findings show that local nucleosome dynamics drive chromatin accessibility. We propose that this local nucleosome fluctuation is the basis for scanning genome information.
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39
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Samejima K, Samejima I, Vagnarelli P, Ogawa H, Vargiu G, Kelly DA, de Lima Alves F, Kerr A, Green LC, Hudson DF, Ohta S, Cooke CA, Farr CJ, Rappsilber J, Earnshaw WC. Mitotic chromosomes are compacted laterally by KIF4 and condensin and axially by topoisomerase IIα. ACTA ACUST UNITED AC 2012; 199:755-70. [PMID: 23166350 PMCID: PMC3514791 DOI: 10.1083/jcb.201202155] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During the shaping of mitotic chromosomes, KIF4 and condensin work in parallel to promote lateral chromatid compaction and in opposition to topoisomerase IIα, which shortens the chromatid arms. Mitotic chromosome formation involves a relatively minor condensation of the chromatin volume coupled with a dramatic reorganization into the characteristic “X” shape. Here we report results of a detailed morphological analysis, which revealed that chromokinesin KIF4 cooperated in a parallel pathway with condensin complexes to promote the lateral compaction of chromatid arms. In this analysis, KIF4 and condensin were mutually dependent for their dynamic localization on the chromatid axes. Depletion of either caused sister chromatids to expand and compromised the “intrinsic structure” of the chromosomes (defined in an in vitro assay), with loss of condensin showing stronger effects. Simultaneous depletion of KIF4 and condensin caused complete loss of chromosome morphology. In these experiments, topoisomerase IIα contributed to shaping mitotic chromosomes by promoting the shortening of the chromatid axes and apparently acting in opposition to the actions of KIF4 and condensins. These three proteins are major determinants in shaping the characteristic mitotic chromosome morphology.
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Affiliation(s)
- Kumiko Samejima
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, King's Buildings, Edinburgh EH9 3JR, Scotland, UK
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40
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Wang F, Ulyanova NP, Daum JR, Patnaik D, Kateneva AV, Gorbsky GJ, Higgins JM. Haspin inhibitors reveal centromeric functions of Aurora B in chromosome segregation. J Cell Biol 2012; 199:251-68. [PMID: 23071152 PMCID: PMC3471242 DOI: 10.1083/jcb.201205106] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 09/18/2012] [Indexed: 01/14/2023] Open
Abstract
Haspin phosphorylates histone H3 at threonine-3 (H3T3ph), providing a docking site for the Aurora B complex at centromeres. Aurora B functions to correct improper kinetochore-microtubule attachments and alert the spindle checkpoint to the presence of misaligned chromosomes. We show that Haspin inhibitors decreased H3T3ph, resulting in loss of centromeric Aurora B and reduced phosphorylation of centromere and kinetochore Aurora B substrates. Consequently, metaphase chromosome alignment and spindle checkpoint signaling were compromised. These effects were phenocopied by microinjection of anti-H3T3ph antibodies. Retargeting Aurora B to centromeres partially restored checkpoint signaling and Aurora B-dependent phosphorylation at centromeres and kinetochores, bypassing the need for Haspin activity. Haspin inhibitors did not obviously affect phosphorylation of histone H3 at serine-10 (H3S10ph) by Aurora B on chromosome arms but, in Aurora B reactivation assays, recovery of H3S10ph was delayed. Haspin inhibitors did not block Aurora B localization to the spindle midzone in anaphase or Aurora B function in cytokinesis. Thus, Haspin inhibitors reveal centromeric roles of Aurora B in chromosome movement and spindle checkpoint signaling.
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Affiliation(s)
- Fangwei Wang
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Natalia P. Ulyanova
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
| | - John R. Daum
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Debasis Patnaik
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Anna V. Kateneva
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Gary J. Gorbsky
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Jonathan M.G. Higgins
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
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41
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Vagnarelli P. Mitotic chromosome condensation in vertebrates. Exp Cell Res 2012; 318:1435-41. [DOI: 10.1016/j.yexcr.2012.03.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 03/15/2012] [Accepted: 03/15/2012] [Indexed: 01/21/2023]
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42
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A model for chromosome condensation based on the interplay between condensin and topoisomerase II. Trends Genet 2012; 28:110-7. [DOI: 10.1016/j.tig.2011.11.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 11/18/2011] [Accepted: 11/21/2011] [Indexed: 01/15/2023]
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43
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Abstract
Topology is the study of geometric properties that are preserved during bending, twisting and stretching of objects. In the context of the genome, topology is discussed at two interconnected and overlapping levels. The first focuses the DNA double helix itself, and includes alterations such as those triggered by DNA interacting proteins, processes which require the separation of the two DNA strands and DNA knotting. The second level is centered on the higher order organization of DNA into chromosomes, as well as dynamic conformational changes that occur on a chromosomal scale. Here, we refer to the first level as "DNA topology", the second as "chromosome topology". Since their identification, evidences suggesting that the so called structural maintenance of chromosomes (SMC) protein complexes are central to the interplay between DNA and chromosome topology have accumulated. The SMC complexes regulate replication, segregation, repair and transcription, all processes which influence, and are influenced by, DNA and chromosome topology. This review focuses on the details of the relationship between the SMC complexes and topology. It also discusses the possibility that the SMC complexes are united by a capability to sense the geometrical chirality of DNA crossings.
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Affiliation(s)
- Sidney D Carter
- Karolinska Institute, Department of Cell and Molecular Biology, Stockholm, Sweden
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Daban JR. Electron microscopy and atomic force microscopy studies of chromatin and metaphase chromosome structure. Micron 2011; 42:733-50. [PMID: 21703860 DOI: 10.1016/j.micron.2011.05.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 05/01/2011] [Indexed: 11/26/2022]
Abstract
The folding of the chromatin filament and, in particular, the organization of genomic DNA within metaphase chromosomes has attracted the interest of many laboratories during the last five decades. This review discusses our current understanding of chromatin higher-order structure based on results obtained with transmission electron microscopy (TEM), cryo-electron microscopy (cryo-EM), and different atomic force microscopy (AFM) techniques. Chromatin isolated from different cell types in buffers without cations form extended filaments with nucleosomes visible as separated units. In presence of low concentrations of Mg(2+), chromatin filaments are folded into fibers having a diameter of ∼ 30 nm. Highly compact fibers were obtained with isolated chromatin fragments in solutions containing 1-2mM Mg(2+). The high density of these fibers suggested that the successive turns of the chromatin filament are interdigitated. Similar results were obtained with reconstituted nucleosome arrays under the same ionic conditions. This led to the proposal of compact interdigitated solenoid models having a helical pitch of 4-5 nm. These findings, together with the observation of columns of stacked nucleosomes in different liquid crystal phases formed by aggregation of nucleosome core particles at high concentration, and different experimental evidences obtained using other approaches, indicate that face-to-face interactions between nucleosomes are very important for the formation of dense chromatin structures. Chromatin fibers were observed in metaphase chromosome preparations in deionized water and in buffers containing EDTA, but chromosomes in presence of the Mg(2+) concentrations found in metaphase (5-22 mM) are very compact, without visible fibers. Moreover, a recent cryo-electron microscopy analysis of vitreous sections of mitotic cells indicated that chromatin has a disordered organization, which does not support the existence of 30-nm fibers in condensed chromosomes. TEM images of partially denatured chromosomes obtained using different procedures that maintain the ionic conditions of metaphase showed that bulk chromatin in chromosomes is organized forming multilayered plate-like structures. The structure and mechanical properties of these plates were studied using cryo-EM, electron tomography, AFM imaging in aqueous media, and AFM-based nanotribology and force spectroscopy. The results obtained indicated that the chromatin filament forms a flexible two-dimensional network, in which DNA is the main component responsible for the mechanical strength observed in friction force measurements. The discovery of this unexpected structure based on a planar geometry has opened completely new possibilities for the understanding of chromatin folding in metaphase chromosomes. It was proposed that chromatids are formed by many stacked thin chromatin plates oriented perpendicular to the chromatid axis. Different experimental evidences indicated that nucleosomes in the plates are irregularly oriented, and that the successive layers are interdigitated (the apparent layer thickness is 5-6 nm), allowing face-to-face interactions between nucleosomes of adjacent layers. The high density of this structure is in agreement with the high concentration of DNA observed in metaphase chromosomes of different species, and the irregular orientation of nucleosomes within the plates make these results compatible with those obtained with mitotic cell cryo-sections. The multilaminar chromatin structure proposed for chromosomes allows an easy explanation of chromosome banding and of the band splitting observed in stretched chromosomes.
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Affiliation(s)
- Joan-Ramon Daban
- Departament de Bioquímica i Biologia Molecular, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
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Abstract
Proper mitotic chromosome structure is essential for faithful chromosome segregation. Mounting evidence suggests that mitotic chromosome assembly is a progressive, dynamic process that requires topoisomerase II, condensins and cohesin and the activity of several signalling molecules. Current results suggest how these different activities might interact to achieve the familiar form of the mitotic chromosome.
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Affiliation(s)
- Sandra C Moser
- Wellcome Trust Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.
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Ryu H, Furuta M, Kirkpatrick D, Gygi SP, Azuma Y. PIASy-dependent SUMOylation regulates DNA topoisomerase IIalpha activity. J Cell Biol 2010; 191:783-94. [PMID: 21079245 PMCID: PMC2983052 DOI: 10.1083/jcb.201004033] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 10/13/2010] [Indexed: 11/30/2022] Open
Abstract
DNA topoisomerase IIα (TopoIIα) is an essential chromosome-associated enzyme with activity implicated in the resolution of tangled DNA at centromeres before anaphase onset. However, the regulatory mechanism of TopoIIα activity is not understood. Here, we show that PIASy-mediated small ubiquitin-like modifier 2/3 (SUMO2/3) modification of TopoIIα strongly inhibits TopoIIα decatenation activity. Using mass spectrometry and biochemical analysis, we demonstrate that TopoIIα is SUMOylated at lysine 660 (Lys660), a residue located in the DNA gate domain, where both DNA cleavage and religation take place. Remarkably, loss of SUMOylation on Lys660 eliminates SUMOylation-dependent inhibition of TopoIIα, which indicates that Lys660 SUMOylation is critical for PIASy-mediated inhibition of TopoIIα activity. Together, our findings provide evidence for the regulation of TopoIIα activity on mitotic chromosomes by SUMOylation. Therefore, we propose a novel mechanism for regulation of centromeric DNA catenation during mitosis by PIASy-mediated SUMOylation of TopoIIα.
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Affiliation(s)
- Hyunju Ryu
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
| | - Maiko Furuta
- Laboratory of Gene Regulation and Development, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | | | - Steven P. Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Yoshiaki Azuma
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
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Sheval EV, Dudnik OA, Abramchuk SS, Polyakov VY. Perichromosomal layer proteins associate with chromosome scaffold and nuclear matrix throughout the cell cycle. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2009. [DOI: 10.1134/s199074780902010x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lee MT, Bachant J. SUMO modification of DNA topoisomerase II: trying to get a CENse of it all. DNA Repair (Amst) 2009; 8:557-68. [PMID: 19230795 DOI: 10.1016/j.dnarep.2009.01.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
DNA topoisomerase II (topo II) is an essential determinant of chromosome structure and function, acting to resolve topological problems inherent in recombining, transcribing, replicating and segregating DNA. In particular, the unique decatenating activity of topo II is required for sister chromatids to disjoin and separate in mitosis. Topo II exhibits a dynamic localization pattern on mitotic chromosomes, accumulating at centromeres and axial chromosome cores prior to anaphase. In organisms ranging from yeast to humans, a fraction of topo II is targeted for SUMO conjugation in mitotic cells, and here we review our current understanding of the significance of this modification. As we shall see, an emerging consensus is that in metazoans SUMO modification is required for topo II to accumulate at centromeres, and that in the absence of this regulation there is an elevated frequency of chromosome non-disjunction, segregation errors, and aneuploidy. The underlying molecular mechanisms for how SUMO controls topo II are as yet unclear. In closing, however, we will evaluate two possible interpretations: one in which SUMO promotes enzyme turnover, and a second in which SUMO acts as a localization tag for topo II chromosome trafficking.
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Affiliation(s)
- Ming-Ta Lee
- Department of Cell Biology and Neuroscience, University of California, Riverside, Riverside, CA 92521, USA
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Dense chromatin plates in metaphase chromosomes. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 38:503-22. [DOI: 10.1007/s00249-008-0401-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 12/11/2008] [Accepted: 12/19/2008] [Indexed: 10/21/2022]
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Giménez-Abián JF, Clarke DJ. Cytological analysis of chromosome structural defects that result from topoisomerase II dysfunction. Methods Mol Biol 2009; 582:189-207. [PMID: 19763951 DOI: 10.1007/978-1-60761-340-4_15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
For analyzing chromosome structural defects that result from topoisomerase II (topo II) dysfunction, we have adapted classical cell cycle experiments, classical cytological techniques, and the use of a potent topo II inhibitor (ICRF-193). In this chapter, we describe in detail the protocols used and we discuss the rationale for our choice and for the adaptations applied. We clarify in which cell cycle stages each of the different chromosomal aberrations induced by inhibiting topo II take place: lack of chromosome segregation, undercondensation, lack of sister chromatid resolution, and lack of chromosome individualization. We also put these observations into the context of the two topo II-dependent cell cycle checkpoints.
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