1
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Yellman CM. Saccharomyces cerevisiae deficient in the early anaphase release of Cdc14 can traverse anaphase I without ribosomal DNA disjunction and successfully complete meiosis. Biol Open 2023; 12:bio059853. [PMID: 37530060 PMCID: PMC10621906 DOI: 10.1242/bio.059853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 07/27/2023] [Indexed: 08/03/2023] Open
Abstract
Eukaryotic meiosis is a specialized cell cycle of two nuclear divisions that give rise to haploid gametes. The phosphatase Cdc14 is essential for meiosis in the yeast Saccharomyces cerevisiae. Cdc14 is sequestered in the nucleolus, a nuclear domain containing the ribosomal DNA, by its binding partner Net1, and released in two distinct waves, first in early anaphase I, then in anaphase II. Current models posit that the meiosis I release is required for ribosomal DNA disjunction, disassembly of the anaphase spindle, spindle pole re-duplication and counteraction of cyclin-dependent kinase, all of which are essential events. We examined Cdc14 release in net1-6cdk mutant cells, which lack six key Net1 CDK phosphorylation sites. Cdc14 release in early anaphase I was partially inhibited, and disjunction of the rDNA was fully inhibited. Failure to disjoin the rDNA is lethal in mitosis, and we expected the same to be true for meiosis I. However, the cells reliably completed both meiotic divisions to produce four viable spores. Therefore, segregation of the rDNA into all four meiotic products can be postponed until meiosis II without decreasing the fidelity of chromosome inheritance.
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Affiliation(s)
- Christopher M. Yellman
- Department of Biology, Georgetown University, 301 Regents Hall, 6411 Tondorf Road, Washington, DC 20007, USA
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2
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Sasaki M, Kobayashi T. Regulatory processes that maintain or alter ribosomal DNA stability during the repair of programmed DNA double-strand breaks. Genes Genet Syst 2023; 98:103-119. [PMID: 35922917 DOI: 10.1266/ggs.22-00046] [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] [Indexed: 11/23/2022] Open
Abstract
Organisms have evolved elaborate mechanisms that maintain genome stability. Deficiencies in these mechanisms result in changes to the nucleotide sequence as well as copy number and structural variations in the genome. Genome instability has been implicated in numerous human diseases. However, genomic alterations can also be beneficial as they are an essential part of the evolutionary process. Organisms sometimes program genomic changes that drive genetic and phenotypic diversity. Therefore, genome alterations can have both positive and negative impacts on cellular growth and functions, which underscores the need to control the processes that restrict or induce such changes to the genome. The ribosomal RNA gene (rDNA) is highly abundant in eukaryotic genomes, forming a cluster where numerous rDNA copies are tandemly arrayed. Budding yeast can alter the stability of its rDNA cluster by changing the rDNA copy number within the cluster or by producing extrachromosomal rDNA circles. Here, we review the mechanisms that regulate the stability of the budding yeast rDNA cluster during repair of DNA double-strand breaks that are formed in response to programmed DNA replication fork arrest.
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Affiliation(s)
- Mariko Sasaki
- Laboratory of Genome Regeneration, Institute for Quantitative Biosciences (IQB), The University of Tokyo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo
| | - Takehiko Kobayashi
- Laboratory of Genome Regeneration, Institute for Quantitative Biosciences (IQB), The University of Tokyo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo
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3
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Zhang Y, Pang Y, Zhang K, Song X, Gao J, Zhang S, Deng W. RNA polymerase I subunit RPA43 activates rRNA expression and cell proliferation but inhibits cell migration. Biochim Biophys Acta Gen Subj 2023:130411. [PMID: 37343605 DOI: 10.1016/j.bbagen.2023.130411] [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: 01/30/2023] [Revised: 05/21/2023] [Accepted: 06/13/2023] [Indexed: 06/23/2023]
Abstract
The products synthesized by RNA polymerase I (Pol I) play fundamental roles in several cellular processes, including ribosomal biogenesis, protein synthesis, cell metabolism, and growth. Deregulation of Pol I products can cause various diseases such as ribosomopathies, leukaemia, and solid tumours. However, the detailed mechanism of Pol I-directed transcription remains elusive, and the roles of Pol I subunits in rRNA synthesis and cellular activities still need clarification. In this study, we found that RPA43 expression levels positively correlate with Pol I product accumulation and cell proliferation, indicating that RPA43 activates these processes. Unexpectedly, RPA43 depletion promoted HeLa cell migration, suggesting that RPA43 functions as a negative regulator in cell migration. Mechanistically, RPA43 positively modulates the recruitment of Pol I transcription machinery factors to the rDNA promoter by activating the transcription of the genes encoding Pol I transcription machinery factors. RPA43 inhibits cell migration by dampening the expression of c-JUN and Integrin. Collectively, we found that RPA43 plays opposite roles in cell proliferation and migration except for driving Pol I-dependent transcription. These findings provide novel insights into the regulatory mechanism of Pol I-mediated transcription and cell proliferation and a potential pathway to developing anti-cancer drugs using RPA43 as a target.
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Affiliation(s)
- Yue Zhang
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Yaoyu Pang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7GE, UK
| | - Kewei Zhang
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Xiaoye Song
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Junwei Gao
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Shuting Zhang
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Wensheng Deng
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China.
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4
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Santana-Sosa S, Matos-Perdomo E, Ayra-Plasencia J, Machín F. A Yeast Mitotic Tale for the Nucleus and the Vacuoles to Embrace. Int J Mol Sci 2023; 24:9829. [PMID: 37372977 DOI: 10.3390/ijms24129829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/02/2023] [Accepted: 06/03/2023] [Indexed: 06/29/2023] Open
Abstract
The morphology of the nucleus is roughly spherical in most eukaryotic cells. However, this organelle shape needs to change as the cell travels through narrow intercellular spaces during cell migration and during cell division in organisms that undergo closed mitosis, i.e., without dismantling the nuclear envelope, such as yeast. In addition, the nuclear morphology is often modified under stress and in pathological conditions, being a hallmark of cancer and senescent cells. Thus, understanding nuclear morphological dynamics is of uttermost importance, as pathways and proteins involved in nuclear shaping can be targeted in anticancer, antiaging, and antifungal therapies. Here, we review how and why the nuclear shape changes during mitotic blocks in yeast, introducing novel data that associate these changes with both the nucleolus and the vacuole. Altogether, these findings suggest a close relationship between the nucleolar domain of the nucleus and the autophagic organelle, which we also discuss here. Encouragingly, recent evidence in tumor cell lines has linked aberrant nuclear morphology to defects in lysosomal function.
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Affiliation(s)
- Silvia Santana-Sosa
- Research Unit, University Hospital Ntra Sra de Candelaria, Ctra del Rosario 145, 38010 Santa Cruz de Tenerife, Spain
- Institute of Biomedical Technologies, University of La Laguna, 38200 San Cristóbal de La Laguna, Spain
| | - Emiliano Matos-Perdomo
- Research Unit, University Hospital Ntra Sra de Candelaria, Ctra del Rosario 145, 38010 Santa Cruz de Tenerife, Spain
- Institute of Biomedical Technologies, University of La Laguna, 38200 San Cristóbal de La Laguna, Spain
| | - Jessel Ayra-Plasencia
- Research Unit, University Hospital Ntra Sra de Candelaria, Ctra del Rosario 145, 38010 Santa Cruz de Tenerife, Spain
- Institute of Biomedical Technologies, University of La Laguna, 38200 San Cristóbal de La Laguna, Spain
| | - Félix Machín
- Research Unit, University Hospital Ntra Sra de Candelaria, Ctra del Rosario 145, 38010 Santa Cruz de Tenerife, Spain
- Institute of Biomedical Technologies, University of La Laguna, 38200 San Cristóbal de La Laguna, Spain
- Faculty of Health Sciences, Fernando Pessoa Canarias University, 35450 Santa María de Guía, Spain
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5
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Campos A, Ramos F, Iglesias L, Delgado C, Merino E, Esperilla-Muñoz A, Correa-Bordes J, Clemente-Blanco A. Cdc14 phosphatase counteracts Cdk-dependent Dna2 phosphorylation to inhibit resection during recombinational DNA repair. Nat Commun 2023; 14:2738. [PMID: 37173316 PMCID: PMC10182099 DOI: 10.1038/s41467-023-38417-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 04/28/2023] [Indexed: 05/15/2023] Open
Abstract
Cyclin-dependent kinase (Cdk) stimulates resection of DNA double-strand breaks ends to generate single-stranded DNA (ssDNA) needed for recombinational DNA repair. Here we show in Saccharomyces cerevisiae that lack of the Cdk-counteracting phosphatase Cdc14 produces abnormally extended resected tracts at the DNA break ends, involving the phosphatase in the inhibition of resection. Over-resection in the absence of Cdc14 activity is bypassed when the exonuclease Dna2 is inactivated or when its Cdk consensus sites are mutated, indicating that the phosphatase restrains resection by acting through this nuclease. Accordingly, mitotically activated Cdc14 promotes Dna2 dephosphorylation to exclude it from the DNA lesion. Cdc14-dependent resection inhibition is essential to sustain DNA re-synthesis, thus ensuring the appropriate length, frequency, and distribution of the gene conversion tracts. These results establish a role for Cdc14 in controlling the extent of resection through Dna2 regulation and demonstrate that the accumulation of excessively long ssDNA affects the accurate repair of the broken DNA by homologous recombination.
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Affiliation(s)
- Adrián Campos
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica (IBFG), CSIC-USAL, Salamanca, Spain
| | - Facundo Ramos
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica (IBFG), CSIC-USAL, Salamanca, Spain
| | - Lydia Iglesias
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica (IBFG), CSIC-USAL, Salamanca, Spain
| | - Celia Delgado
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica (IBFG), CSIC-USAL, Salamanca, Spain
| | - Eva Merino
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica (IBFG), CSIC-USAL, Salamanca, Spain
| | | | - Jaime Correa-Bordes
- Departamento de Ciencias Biomédicas, Universidad de Extremadura, Badajoz, Spain
| | - Andrés Clemente-Blanco
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica (IBFG), CSIC-USAL, Salamanca, Spain.
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6
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Regulation of ribosomal RNA gene copy number, transcription and nucleolus organization in eukaryotes. Nat Rev Mol Cell Biol 2023; 24:414-429. [PMID: 36732602 DOI: 10.1038/s41580-022-00573-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2022] [Indexed: 02/04/2023]
Abstract
One of the first biological machineries to be created seems to have been the ribosome. Since then, organisms have dedicated great efforts to optimize this apparatus. The ribosomal RNA (rRNA) contained within ribosomes is crucial for protein synthesis and maintenance of cellular function in all known organisms. In eukaryotic cells, rRNA is produced from ribosomal DNA clusters of tandem rRNA genes, whose organization in the nucleolus, maintenance and transcription are strictly regulated to satisfy the substantial demand for rRNA required for ribosome biogenesis. Recent studies have elucidated mechanisms underlying the integrity of ribosomal DNA and regulation of its transcription, including epigenetic mechanisms and a unique recombination and copy-number control system to stably maintain high rRNA gene copy number. In this Review, we disucss how the crucial maintenance of rRNA gene copy number through control of gene amplification and of rRNA production by RNA polymerase I are orchestrated. We also discuss how liquid-liquid phase separation controls the architecture and function of the nucleolus and the relationship between rRNA production, cell senescence and disease.
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7
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Matos-Perdomo E, Santana-Sosa S, Ayra-Plasencia J, Medina-Suárez S, Machín F. The vacuole shapes the nucleus and the ribosomal DNA loop during mitotic delays. Life Sci Alliance 2022; 5:5/10/e202101161. [PMID: 35961781 PMCID: PMC9375157 DOI: 10.26508/lsa.202101161] [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: 07/15/2021] [Revised: 07/20/2022] [Accepted: 07/20/2022] [Indexed: 11/24/2022] Open
Abstract
Chromosome structuring and condensation is one of the main features of mitosis. Here, Matos-Perdomo et al show how the nuclear envelope reshapes around the vacuole to give rise to the outstanding ribosomal DNA loop in budding yeast. The ribosomal DNA (rDNA) array of Saccharomyces cerevisiae has served as a model to address chromosome organization. In cells arrested before anaphase (mid-M), the rDNA acquires a highly structured chromosomal organization referred to as the rDNA loop, whose length can double the cell diameter. Previous works established that complexes such as condensin and cohesin are essential to attain this structure. Here, we report that the rDNA loop adopts distinct presentations that arise as spatial adaptations to changes in the nuclear morphology triggered during mid-M arrests. Interestingly, the formation of the rDNA loop results in the appearance of a space under the loop (SUL) which is devoid of nuclear components yet colocalizes with the vacuole. We show that the rDNA-associated nuclear envelope (NE) often reshapes into a ladle to accommodate the vacuole in the SUL, with the nucleus becoming bilobed and doughnut-shaped. Finally, we demonstrate that the formation of the rDNA loop and the SUL require TORC1, membrane synthesis and functional vacuoles, yet is independent of nucleus–vacuole junctions and rDNA-NE tethering.
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Affiliation(s)
- Emiliano Matos-Perdomo
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain.,Escuela de Doctorado y Estudios de Postgrado, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Silvia Santana-Sosa
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain.,Escuela de Doctorado y Estudios de Postgrado, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Jessel Ayra-Plasencia
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain.,Escuela de Doctorado y Estudios de Postgrado, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Sara Medina-Suárez
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain.,Escuela de Doctorado y Estudios de Postgrado, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Félix Machín
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain .,Instituto de Tecnologías Biomédicas, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.,Facultad de Ciencias de la Salud, Universidad Fernando Pessoa Canarias, Santa María de Guía, Spain
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8
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Interphase chromosome condensation in nutrient-starved conditions requires Cdc14 and Hmo1, but not condensin, in yeast. Biochem Biophys Res Commun 2022; 611:46-52. [PMID: 35477092 DOI: 10.1016/j.bbrc.2022.04.078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 04/17/2022] [Indexed: 12/21/2022]
Abstract
When asynchronously growing cells suffer from nutrient depletion and inactivation of target of rapamycin complex 1 (TORC1) protein kinase, the rDNA (rRNA gene) region is condensed in budding yeast Saccharomyces cerevisiae, which is executed by condensin and Cdc14 protein phosphatase. However, it is unknown whether these mitotic factors can condense the rDNA region in nutrient-starved interphase cells. Here, we show that condensin is not involved in TORC1 inactivation-induced rDNA condensation in G1 cells. Instead, the high-mobility group protein Hmo1 drove this process. The histone deacetylase Rpd3 and Cdc14, which repress rRNA transcription, were both required for the interphase rDNA condensation. Furthermore, interphase rDNA condensation necessitated CLIP and cohibin that tether rDNA to inner nuclear membranes. Finally, we showed that Hmo1, CLIP, Rpd3, and Cdc14 were required for survival in nutrient-starved G1 cells. Thus, this study disclosed novel features of interphase chromosome condensation.
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9
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Enserink JM, Chymkowitch P. Cell Cycle-Dependent Transcription: The Cyclin Dependent Kinase Cdk1 Is a Direct Regulator of Basal Transcription Machineries. Int J Mol Sci 2022; 23:ijms23031293. [PMID: 35163213 PMCID: PMC8835803 DOI: 10.3390/ijms23031293] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/22/2022] [Accepted: 01/22/2022] [Indexed: 12/21/2022] Open
Abstract
The cyclin-dependent kinase Cdk1 is best known for its function as master regulator of the cell cycle. It phosphorylates several key proteins to control progression through the different phases of the cell cycle. However, studies conducted several decades ago with mammalian cells revealed that Cdk1 also directly regulates the basal transcription machinery, most notably RNA polymerase II. More recent studies in the budding yeast Saccharomyces cerevisiae have revisited this function of Cdk1 and also revealed that Cdk1 directly controls RNA polymerase III activity. These studies have also provided novel insight into the physiological relevance of this process. For instance, cell cycle-stage-dependent activity of these complexes may be important for meeting the increased demand for various proteins involved in housekeeping, metabolism, and protein synthesis. Recent work also indicates that direct regulation of the RNA polymerase II machinery promotes cell cycle entry. Here, we provide an overview of the regulation of basal transcription by Cdk1, and we hypothesize that the original function of the primordial cell-cycle CDK was to regulate RNAPII and that it later evolved into specialized kinases that govern various aspects of the transcription machinery and the cell cycle.
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Affiliation(s)
- Jorrit M. Enserink
- Section for Biochemistry and Molecular Biology, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, 0379 Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0318 Oslo, Norway
- Correspondence: (J.M.E.); (P.C.)
| | - Pierre Chymkowitch
- Section for Biochemistry and Molecular Biology, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
- Department of Microbiology, Oslo University Hospital, 0372 Oslo, Norway
- Correspondence: (J.M.E.); (P.C.)
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10
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Pilsl M, Engel C. Structural Studies of Eukaryotic RNA Polymerase I Using Cryo-Electron Microscopy. Methods Mol Biol 2022; 2533:71-80. [PMID: 35796983 PMCID: PMC9761920 DOI: 10.1007/978-1-0716-2501-9_5] [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] [Indexed: 06/15/2023]
Abstract
Technical advances have pushed the resolution limit of single-particle cryo-electron microscopy (cryo-EM) throughout the past decade and made the technique accessible to a wide range of samples. Among them, multisubunit DNA-dependent RNA polymerases (Pols) are a prominent example. This review aims at briefly summarizing the architecture and structural adaptations of Pol I, highlighting the importance of cryo-electron microscopy in determining the structures of transcription complexes.
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Affiliation(s)
- Michael Pilsl
- Regensburg Center for Biochemistry (RCB), University of Regensburg, Regensburg, Germany
| | - Christoph Engel
- Regensburg Center for Biochemistry (RCB), University of Regensburg, Regensburg, Germany.
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11
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Alonso-Ramos P, Álvarez-Melo D, Strouhalova K, Pascual-Silva C, Garside GB, Arter M, Bermejo T, Grigaitis R, Wettstein R, Fernández-Díaz M, Matos J, Geymonat M, San-Segundo PA, Carballo JA. The Cdc14 Phosphatase Controls Resolution of Recombination Intermediates and Crossover Formation during Meiosis. Int J Mol Sci 2021; 22:ijms22189811. [PMID: 34575966 PMCID: PMC8470964 DOI: 10.3390/ijms22189811] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 12/15/2022] Open
Abstract
Meiotic defects derived from incorrect DNA repair during gametogenesis can lead to mutations, aneuploidies and infertility. The coordinated resolution of meiotic recombination intermediates is required for crossover formation, ultimately necessary for the accurate completion of both rounds of chromosome segregation. Numerous master kinases orchestrate the correct assembly and activity of the repair machinery. Although much less is known, the reversal of phosphorylation events in meiosis must also be key to coordinate the timing and functionality of repair enzymes. Cdc14 is a crucial phosphatase required for the dephosphorylation of multiple CDK1 targets in many eukaryotes. Mutations that inactivate this phosphatase lead to meiotic failure, but until now it was unknown if Cdc14 plays a direct role in meiotic recombination. Here, we show that the elimination of Cdc14 leads to severe defects in the processing and resolution of recombination intermediates, causing a drastic depletion in crossovers when other repair pathways are compromised. We also show that Cdc14 is required for the correct activity and localization of the Holliday Junction resolvase Yen1/GEN1. We reveal that Cdc14 regulates Yen1 activity from meiosis I onwards, and this function is essential for crossover resolution in the absence of other repair pathways. We also demonstrate that Cdc14 and Yen1 are required to safeguard sister chromatid segregation during the second meiotic division, a late action that is independent of the earlier role in crossover formation. Thus, this work uncovers previously undescribed functions of the evolutionary conserved Cdc14 phosphatase in the regulation of meiotic recombination.
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Affiliation(s)
- Paula Alonso-Ramos
- Center for Biological Research Margarita Salas, Department of Cellular and Molecular Biology, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (P.A.-R.); (D.Á.-M.); (K.S.); (C.P.-S.); (T.B.); (M.F.-D.)
| | - David Álvarez-Melo
- Center for Biological Research Margarita Salas, Department of Cellular and Molecular Biology, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (P.A.-R.); (D.Á.-M.); (K.S.); (C.P.-S.); (T.B.); (M.F.-D.)
| | - Katerina Strouhalova
- Center for Biological Research Margarita Salas, Department of Cellular and Molecular Biology, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (P.A.-R.); (D.Á.-M.); (K.S.); (C.P.-S.); (T.B.); (M.F.-D.)
- Department of Cell Biology, Charles University, Viničná 7, 12843 Prague, Czech Republic
| | - Carolina Pascual-Silva
- Center for Biological Research Margarita Salas, Department of Cellular and Molecular Biology, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (P.A.-R.); (D.Á.-M.); (K.S.); (C.P.-S.); (T.B.); (M.F.-D.)
| | - George B. Garside
- Genome Damage and Stability Centre, University of Sussex, Brighton BN1 4DY, UK;
- Leibniz Institute for Age Research/Fritz Lipmann Institute (FLI), Beutenbergstr. 11, D-07745 Jena, Germany
| | - Meret Arter
- Institute of Biochemistry, HPM D6.5-ETH Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland; (M.A.); (R.G.); (R.W.); (J.M.)
- Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Teresa Bermejo
- Center for Biological Research Margarita Salas, Department of Cellular and Molecular Biology, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (P.A.-R.); (D.Á.-M.); (K.S.); (C.P.-S.); (T.B.); (M.F.-D.)
| | - Rokas Grigaitis
- Institute of Biochemistry, HPM D6.5-ETH Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland; (M.A.); (R.G.); (R.W.); (J.M.)
- Max Perutz Labs, University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Rahel Wettstein
- Institute of Biochemistry, HPM D6.5-ETH Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland; (M.A.); (R.G.); (R.W.); (J.M.)
- Max Perutz Labs, University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Marta Fernández-Díaz
- Center for Biological Research Margarita Salas, Department of Cellular and Molecular Biology, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (P.A.-R.); (D.Á.-M.); (K.S.); (C.P.-S.); (T.B.); (M.F.-D.)
| | - Joao Matos
- Institute of Biochemistry, HPM D6.5-ETH Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland; (M.A.); (R.G.); (R.W.); (J.M.)
- Max Perutz Labs, University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Marco Geymonat
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK;
| | - Pedro A. San-Segundo
- Institute of Functional Biology and Genomics (IBFG), Spanish National Research Council (CSIC) and University of Salamanca, 37007 Salamanca, Spain;
| | - Jesús A. Carballo
- Center for Biological Research Margarita Salas, Department of Cellular and Molecular Biology, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (P.A.-R.); (D.Á.-M.); (K.S.); (C.P.-S.); (T.B.); (M.F.-D.)
- Correspondence:
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12
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Delgado-Román I, Muñoz-Centeno MC. Coupling Between Cell Cycle Progression and the Nuclear RNA Polymerases System. Front Mol Biosci 2021; 8:691636. [PMID: 34409067 PMCID: PMC8365833 DOI: 10.3389/fmolb.2021.691636] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
Eukaryotic life is possible due to the multitude of complex and precise phenomena that take place in the cell. Essential processes like gene transcription, mRNA translation, cell growth, and proliferation, or membrane traffic, among many others, are strictly regulated to ensure functional success. Such systems or vital processes do not work and adjusts independently of each other. It is required to ensure coordination among them which requires communication, or crosstalk, between their different elements through the establishment of complex regulatory networks. Distortion of this coordination affects, not only the specific processes involved, but also the whole cell fate. However, the connection between some systems and cell fate, is not yet very well understood and opens lots of interesting questions. In this review, we focus on the coordination between the function of the three nuclear RNA polymerases and cell cycle progression. Although we mainly focus on the model organism Saccharomyces cerevisiae, different aspects and similarities in higher eukaryotes are also addressed. We will first focus on how the different phases of the cell cycle affect the RNA polymerases activity and then how RNA polymerases status impacts on cell cycle. A good example of how RNA polymerases functions impact on cell cycle is the ribosome biogenesis process, which needs the coordinated and balanced production of mRNAs and rRNAs synthesized by the three eukaryotic RNA polymerases. Distortions of this balance generates ribosome biogenesis alterations that can impact cell cycle progression. We also pay attention to those cases where specific cell cycle defects generate in response to repressed synthesis of ribosomal proteins or RNA polymerases assembly defects.
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Affiliation(s)
- Irene Delgado-Román
- Instituto de Biomedicina de Sevilla, Universidad de Sevilla-CSIC-Hospital Universitario V. Del Rocío, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Mari Cruz Muñoz-Centeno
- Instituto de Biomedicina de Sevilla, Universidad de Sevilla-CSIC-Hospital Universitario V. Del Rocío, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
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13
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González-Jiménez A, Campos A, Navarro F, Clemente-Blanco A, Calvo O. Regulation of Eukaryotic RNAPs Activities by Phosphorylation. Front Mol Biosci 2021; 8:681865. [PMID: 34250017 PMCID: PMC8268151 DOI: 10.3389/fmolb.2021.681865] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/07/2021] [Indexed: 01/11/2023] Open
Abstract
Evolutionarily conserved kinases and phosphatases regulate RNA polymerase II (RNAPII) transcript synthesis by modifying the phosphorylation status of the carboxyl-terminal domain (CTD) of Rpb1, the largest subunit of RNAPII. Proper levels of Rpb1-CTD phosphorylation are required for RNA co-transcriptional processing and to coordinate transcription with other nuclear processes, such as chromatin remodeling and histone modification. Whether other RNAPII subunits are phosphorylated and influences their role in gene expression is still an unanswered question. Much less is known about RNAPI and RNAPIII phosphorylation, whose subunits do not contain functional CTDs. However, diverse studies have reported that several RNAPI and RNAPIII subunits are susceptible to phosphorylation. Some of these phosphorylation sites are distributed within subunits common to all three RNAPs whereas others are only shared between RNAPI and RNAPIII. This suggests that the activities of all RNAPs might be finely modulated by phosphorylation events and raises the idea of a tight coordination between the three RNAPs. Supporting this view, the transcription by all RNAPs is regulated by signaling pathways that sense different environmental cues to adapt a global RNA transcriptional response. This review focuses on how the phosphorylation of RNAPs might regulate their function and we comment on the regulation by phosphorylation of some key transcription factors in the case of RNAPI and RNAPIII. Finally, we discuss the existence of possible common mechanisms that could coordinate their activities.
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Affiliation(s)
- Araceli González-Jiménez
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Adrián Campos
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Jaén, Spain.,Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Jaén, Spain
| | - Andrés Clemente-Blanco
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Olga Calvo
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
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14
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Rivosecchi J, Jost D, Vachez L, Gautier FD, Bernard P, Vanoosthuyse V. RNA polymerase backtracking results in the accumulation of fission yeast condensin at active genes. Life Sci Alliance 2021; 4:4/6/e202101046. [PMID: 33771877 PMCID: PMC8046420 DOI: 10.26508/lsa.202101046] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/04/2021] [Accepted: 03/07/2021] [Indexed: 12/23/2022] Open
Abstract
Using both experiments and mathematical modelling, the authors show that RNA polymerase backtracking contributes to the accumulation of condensin in the termination zone of active genes. The mechanisms leading to the accumulation of the SMC complexes condensins around specific transcription units remain unclear. Observations made in bacteria suggested that RNA polymerases (RNAPs) constitute an obstacle to SMC translocation, particularly when RNAP and SMC travel in opposite directions. Here we show in fission yeast that gene termini harbour intrinsic condensin-accumulating features whatever the orientation of transcription, which we attribute to the frequent backtracking of RNAP at gene ends. Consistent with this, to relocate backtracked RNAP2 from gene termini to gene bodies was sufficient to cancel the accumulation of condensin at gene ends and to redistribute it evenly within transcription units, indicating that RNAP backtracking may play a key role in positioning condensin. Formalization of this hypothesis in a mathematical model suggests that the inclusion of a sub-population of RNAP with longer dwell-times is essential to fully recapitulate the distribution profiles of condensin around active genes. Taken together, our data strengthen the idea that dense arrays of proteins tightly bound to DNA alter the distribution of condensin on chromosomes.
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Affiliation(s)
- Julieta Rivosecchi
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5239, Lyon, France
| | - Daniel Jost
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5239, Lyon, France
| | - Laetitia Vachez
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5239, Lyon, France
| | - François Dr Gautier
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5239, Lyon, France
| | - Pascal Bernard
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5239, Lyon, France
| | - Vincent Vanoosthuyse
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 5239, Lyon, France
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15
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Mostofa MG, Morshed S, Mase S, Hosoyamada S, Kobayashi T, Ushimaru T. Cdc14 protein phosphatase and topoisomerase II mediate rDNA dynamics and nucleophagic degradation of nucleolar proteins after TORC1 inactivation. Cell Signal 2020; 79:109884. [PMID: 33321182 DOI: 10.1016/j.cellsig.2020.109884] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/11/2020] [Accepted: 12/11/2020] [Indexed: 10/22/2022]
Abstract
Nutrient starvation and inactivation of target of rapamycin complex 1 (TORC1) protein kinase elicits nucleophagy degrading nucleolar proteins in budding yeast. After TORC1 inactivation, nucleolar proteins are relocated to sites proximal to the nucleus-vacuole junction (NVJ), where micronucleophagy occurs, whereas ribosomal DNA (rDNA encoding rRNA) escapes from the NVJ. Condensin-mediated rDNA condensation promotes the repositioning and nucleophagic degradation of nucleolar proteins. However, the molecular mechanism of TORC1 inactivation-induced chromosome condensation is still unknown. Here, we show that Cdc14 protein phosphatase and topoisomerase II (Topo II), which are engaged in rDNA condensation in mitosis, facilitate rDNA condensation after TORC1 inactivation. rDNA condensation after rapamycin treatment was compromised in cdc14-1 and top2-4 mutants. In addition, the repositioning of rDNA and nucleolar proteins and nucleophagic degradation of nucleolar proteins were impeded in these mutants. Furthermore, Cdc14 and Topo II were required for the survival of quiescent cells in prolonged nutrient-starved conditions. This study reveals that these factors are critical for starvation responses.
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Affiliation(s)
- Md Golam Mostofa
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
| | - Shamsul Morshed
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
| | - Satoru Mase
- Department of Science, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan
| | - Shun Hosoyamada
- Laboratory of Genome Regeneration, Institute of Molecular and Cellular Biosciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Takehiko Kobayashi
- Laboratory of Genome Regeneration, Institute of Molecular and Cellular Biosciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Takashi Ushimaru
- Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan; Department of Science, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka 422-8021, Japan.
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16
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Ólafsson G, Thorpe PH. Polo kinase recruitment via the constitutive centromere-associated network at the kinetochore elevates centromeric RNA. PLoS Genet 2020; 16:e1008990. [PMID: 32810142 PMCID: PMC7455000 DOI: 10.1371/journal.pgen.1008990] [Citation(s) in RCA: 7] [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: 05/06/2020] [Revised: 08/28/2020] [Accepted: 07/13/2020] [Indexed: 12/23/2022] Open
Abstract
The kinetochore, a multi-protein complex assembled on centromeres, is essential to segregate chromosomes during cell division. Deficiencies in kinetochore function can lead to chromosomal instability and aneuploidy-a hallmark of cancer cells. Kinetochore function is controlled by recruitment of regulatory proteins, many of which have been documented, however their function often remains uncharacterized and many are yet to be identified. To identify candidates of kinetochore regulation we used a proteome-wide protein association strategy in budding yeast and detected many proteins that are involved in post-translational modifications such as kinases, phosphatases and histone modifiers. We focused on the Polo-like kinase, Cdc5, and interrogated which cellular components were sensitive to constitutive Cdc5 localization. The kinetochore is particularly sensitive to constitutive Cdc5 kinase activity. Targeting Cdc5 to different kinetochore subcomplexes produced diverse phenotypes, consistent with multiple distinct functions at the kinetochore. We show that targeting Cdc5 to the inner kinetochore, the constitutive centromere-associated network (CCAN), increases the levels of centromeric RNA via an SPT4 dependent mechanism.
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Affiliation(s)
- Guðjón Ólafsson
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
| | - Peter H. Thorpe
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
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17
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Ivanova T, Maier M, Missarova A, Ziegler-Birling C, Dam M, Gomar-Alba M, Carey LB, Mendoza M. Budding yeast complete DNA synthesis after chromosome segregation begins. Nat Commun 2020; 11:2267. [PMID: 32385287 PMCID: PMC7210879 DOI: 10.1038/s41467-020-16100-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 04/14/2020] [Indexed: 01/22/2023] Open
Abstract
To faithfully transmit genetic information, cells must replicate their entire genome before division. This is thought to be ensured by the temporal separation of replication and chromosome segregation. Here we show that in 20–40% of unperturbed yeast cells, DNA synthesis continues during anaphase, late in mitosis. High cyclin-Cdk activity inhibits DNA synthesis in metaphase, and the decrease in cyclin-Cdk activity during mitotic exit allows DNA synthesis to finish at subtelomeric and some difficult-to-replicate regions. DNA synthesis during late mitosis correlates with elevated mutation rates at subtelomeric regions, including copy number variation. Thus, yeast cells temporally overlap DNA synthesis and chromosome segregation during normal growth, possibly allowing cells to maximize population-level growth rate while simultaneously exploring greater genetic space. In the S phase of the cell cycle, the full genome needs to be replicated before cell division occurs. Here, authors show that in budding yeast DNA synthesis is completed after chromosome segregation begins.
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Affiliation(s)
- Tsvetomira Ivanova
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Michael Maier
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | | | | | - Monica Dam
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Mercè Gomar-Alba
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Lucas B Carey
- Universitat Pompeu Fabra (UPF), Barcelona, Spain. .,Center for Quantitative Biology and Peking-Tsinghua Center for the Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
| | - Manuel Mendoza
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain. .,Universitat Pompeu Fabra (UPF), Barcelona, Spain. .,Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France. .,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France. .,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France. .,Université de Strasbourg, Strasbourg, France.
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18
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Abstract
Proper chromosome segregation is critical for the maintenance of genomic information in every cell division, which is required for cell survival. Cells have orchestrated a myriad of control mechanisms to guarantee proper chromosome segregation. Upon stress, cells induce a number of adaptive responses to maximize survival that range from regulation of gene expression to control of cell-cycle progression. We have found here that in response to osmostress, cells also regulate mitosis to ensure proper telomeric and rDNA segregation during adaptation. Osmostress induces a Hog1-dependent delay of cell-cycle progression in early mitosis by phosphorylating Net1, thereby impairing timely nucleolar release and activation of Cdc14, core elements of mitosis regulation. Thus, Hog1 activation prevents segregation defects to maximize survival. Adaptation to environmental changes is crucial for cell fitness. In Saccharomyces cerevisiae, variations in external osmolarity trigger the activation of the stress-activated protein kinase Hog1 (high-osmolarity glycerol 1), which regulates gene expression, metabolism, and cell-cycle progression. The activation of this kinase leads to the regulation of G1, S, and G2 phases of the cell cycle to prevent genome instability and promote cell survival. Here we show that Hog1 delays mitotic exit when cells are stressed during metaphase. Hog1 phosphorylates the nucleolar protein Net1, altering its affinity for the phosphatase Cdc14, whose activity is essential for mitotic exit and completion of the cell cycle. The untimely release of Cdc14 from the nucleolus upon activation of Hog1 is linked to a defect in ribosomal DNA (rDNA) and telomere segregation, and it ultimately delays cell division. A mutant of Net1 that cannot be phosphorylated by Hog1 displays reduced viability upon osmostress. Thus, Hog1 contributes to maximizing cell survival upon stress by regulating mitotic exit.
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19
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The Multiple Roles of the Cdc14 Phosphatase in Cell Cycle Control. Int J Mol Sci 2020; 21:ijms21030709. [PMID: 31973188 PMCID: PMC7038166 DOI: 10.3390/ijms21030709] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 12/20/2022] Open
Abstract
The Cdc14 phosphatase is a key regulator of mitosis in the budding yeast Saccharomyces cerevisiae. Cdc14 was initially described as playing an essential role in the control of cell cycle progression by promoting mitotic exit on the basis of its capacity to counteract the activity of the cyclin-dependent kinase Cdc28/Cdk1. A compiling body of evidence, however, has later demonstrated that this phosphatase plays other multiple roles in the regulation of mitosis at different cell cycle stages. Here, we summarize our current knowledge about the pivotal role of Cdc14 in cell cycle control, with a special focus in the most recently uncovered functions of the phosphatase.
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20
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Cell Cycle and DNA Repair Regulation in the Damage Response: Protein Phosphatases Take Over the Reins. Int J Mol Sci 2020; 21:ijms21020446. [PMID: 31936707 PMCID: PMC7014277 DOI: 10.3390/ijms21020446] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/29/2019] [Accepted: 01/02/2020] [Indexed: 12/14/2022] Open
Abstract
Cells are constantly suffering genotoxic stresses that affect the integrity of our genetic material. Genotoxic insults must be repaired to avoid the loss or inappropriate transmission of the genetic information, a situation that could lead to the appearance of developmental abnormalities and tumorigenesis. To combat this threat, eukaryotic cells have evolved a set of sophisticated molecular mechanisms that are collectively known as the DNA damage response (DDR). This surveillance system controls several aspects of the cellular response, including the detection of lesions, a temporary cell cycle arrest, and the repair of the broken DNA. While the regulation of the DDR by numerous kinases has been well documented over the last decade, the complex roles of protein dephosphorylation have only recently begun to be investigated. Here, we review recent progress in the characterization of DDR-related protein phosphatases during the response to a DNA lesion, focusing mainly on their ability to modulate the DNA damage checkpoint and the repair of the damaged DNA. We also discuss their protein composition and structure, target specificity, and biochemical regulation along the different stages encompassed in the DDR. The compilation of this information will allow us to better comprehend the physiological significance of protein dephosphorylation in the maintenance of genome integrity and cell viability in response to genotoxic stress.
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21
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Dauban L, Kamgoué A, Wang R, Léger-Silvestre I, Beckouët F, Cantaloube S, Gadal O. Quantification of the dynamic behaviour of ribosomal DNA genes and nucleolus during yeast Saccharomyces cerevisiae cell cycle. J Struct Biol 2019; 208:152-164. [PMID: 31449968 DOI: 10.1016/j.jsb.2019.08.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 11/19/2022]
Abstract
Spatial organisation of chromosomes is a determinant of genome stability and is required for proper mitotic segregation. However, visualization of individual chromatids in living cells and quantification of their geometry, remains technically challenging. Here, we used live cell imaging to quantitate the three-dimensional conformation of yeast Saccharomyces cerevisiae ribosomal DNA (rDNA). rDNA is confined within the nucleolus and is composed of about 200 copies representing about 10% of the yeast genome. To fluorescently label rDNA in living cells, we generated a set of nucleolar proteins fused to GFP or made use of a tagged rDNA, in which lacO repetitions were inserted in each repeat unit. We could show that nucleolus is not modified in appearance, shape or size during interphase while rDNA is highly reorganized. Computationally tracing 3D rDNA paths allowed us to quantitatively assess rDNA size, shape and geometry. During interphase, rDNA was progressively reorganized from a zig-zag segmented line of small size (5,5 µm) to a long, homogeneous, line-like structure of 8,7 µm in metaphase. Most importantly, whatever the cell-cycle stage considered, rDNA fibre could be decomposed in subdomains, as previously suggested for 3D chromatin organisation. Finally, we could determine that spatial reorganisation of these subdomains and establishment of rDNA mitotic organisation is under the control of the cohesin complex.
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Affiliation(s)
- Lise Dauban
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Alain Kamgoué
- Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Renjie Wang
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Isabelle Léger-Silvestre
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Frédéric Beckouët
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Sylvain Cantaloube
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France
| | - Olivier Gadal
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France.
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22
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Matos-Perdomo E, Machín F. Nucleolar and Ribosomal DNA Structure under Stress: Yeast Lessons for Aging and Cancer. Cells 2019; 8:cells8080779. [PMID: 31357498 PMCID: PMC6721496 DOI: 10.3390/cells8080779] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/15/2019] [Accepted: 07/24/2019] [Indexed: 02/06/2023] Open
Abstract
Once thought a mere ribosome factory, the nucleolus has been viewed in recent years as an extremely sensitive gauge of diverse cellular stresses. Emerging concepts in nucleolar biology include the nucleolar stress response (NSR), whereby a series of cell insults have a special impact on the nucleolus. These insults include, among others, ultra-violet radiation (UV), nutrient deprivation, hypoxia and thermal stress. While these stresses might influence nucleolar biology directly or indirectly, other perturbances whose origin resides in the nucleolar biology also trigger nucleolar and systemic stress responses. Among the latter, we find mutations in nucleolar and ribosomal proteins, ribosomal RNA (rRNA) processing inhibitors and ribosomal DNA (rDNA) transcription inhibition. The p53 protein also mediates NSR, leading ultimately to cell cycle arrest, apoptosis, senescence or differentiation. Hence, NSR is gaining importance in cancer biology. The nucleolar size and ribosome biogenesis, and how they connect with the Target of Rapamycin (TOR) signalling pathway, are also becoming important in the biology of aging and cancer. Simple model organisms like the budding yeast Saccharomyces cerevisiae, easy to manipulate genetically, are useful in order to study nucleolar and rDNA structure and their relationship with stress. In this review, we summarize the most important findings related to this topic.
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Affiliation(s)
- Emiliano Matos-Perdomo
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
- Escuela de Doctorado y Estudios de Postgrado, Universidad de La Laguna, 38200 Tenerife, Spain
| | - Félix Machín
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain.
- Instituto de Tecnologías Biomédicas, Universidad de La Laguna, 38200 Tenerife, Spain.
- Facultad de Ciencias de la Salud, Universidad Fernando Pessoa Canarias, 35450 Santa María de Guía, Gran Canaria, Spain.
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23
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Yamamoto TG, Ding DQ, Nagahama Y, Chikashige Y, Haraguchi T, Hiraoka Y. Histone H2A insufficiency causes chromosomal segregation defects due to anaphase chromosome bridge formation at rDNA repeats in fission yeast. Sci Rep 2019; 9:7159. [PMID: 31073221 PMCID: PMC6509349 DOI: 10.1038/s41598-019-43633-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 04/28/2019] [Indexed: 11/16/2022] Open
Abstract
The nucleosome, composed of DNA and a histone core, is the basic structural unit of chromatin. The fission yeast Schizosaccharomyces pombe has two genes of histone H2A, hta1+ and hta2+; these genes encode two protein species of histone H2A (H2Aα and H2Aβ, respectively), which differ in three amino acid residues, and only hta2+ is upregulated during meiosis. However, it is unknown whether S. pombe H2Aα and H2Aβ have functional differences. Therefore, in this study, we examined the possible functional differences between H2Aα and H2Aβ during meiosis in S. pombe. We found that deletion of hta2+, but not hta1+, causes defects in chromosome segregation and spore formation during meiosis. Meiotic defects in hta2+ deletion cells were rescued by expressing additional copies of hta1+ or by expressing hta1+ from the hta2 promoter. This indicated that the defects were caused by insufficient amounts of histone H2A, and not by the amino acid residue differences between H2Aα and H2Aβ. Microscopic observation attributed the chromosome segregation defects to anaphase bridge formation in a chromosomal region at the repeats of ribosomal RNA genes (rDNA repeats). These results suggest that histone H2A insufficiency affects the chromatin structures of rDNA repeats, leading to chromosome missegregation in S. pombe.
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Affiliation(s)
- Takaharu G Yamamoto
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe, 651-2492, Japan
| | - Da-Qiao Ding
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe, 651-2492, Japan
| | - Yuki Nagahama
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe, 651-2492, Japan
| | - Yuji Chikashige
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe, 651-2492, Japan
| | - Tokuko Haraguchi
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe, 651-2492, Japan.,Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, 565-0871, Japan
| | - Yasushi Hiraoka
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe, 651-2492, Japan. .,Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, 565-0871, Japan.
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24
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Hannig K, Babl V, Hergert K, Maier A, Pilsl M, Schächner C, Stöckl U, Milkereit P, Tschochner H, Seufert W, Griesenbeck J. The C-terminal region of Net1 is an activator of RNA polymerase I transcription with conserved features from yeast to human. PLoS Genet 2019; 15:e1008006. [PMID: 30802237 PMCID: PMC6415870 DOI: 10.1371/journal.pgen.1008006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 03/13/2019] [Accepted: 02/05/2019] [Indexed: 01/25/2023] Open
Abstract
RNA polymerase I (Pol I) synthesizes ribosomal RNA (rRNA) in all eukaryotes, accounting for the major part of transcriptional activity in proliferating cells. Although basal Pol I transcription factors have been characterized in diverse organisms, the molecular basis of the robust rRNA production in vivo remains largely unknown. In S. cerevisiae, the multifunctional Net1 protein was reported to stimulate Pol I transcription. We found that the Pol I-stimulating function can be attributed to the very C-terminal region (CTR) of Net1. The CTR was required for normal cell growth and Pol I recruitment to rRNA genes in vivo and sufficient to promote Pol I transcription in vitro. Similarity with the acidic tail region of mammalian Pol I transcription factor UBF, which could partly functionally substitute for the CTR, suggests conserved roles for CTR-like domains in Pol I transcription from yeast to human. The production of ribosomes, cellular factories of protein synthesis, is an essential process driving proliferation and cell growth. Ribosome biogenesis is controlled at the level of synthesis of its components, ribosomal proteins and ribosomal RNA. In eukaryotes, RNA polymerase I is dedicated to transcribe the ribosomal RNA. RNA polymerase I has been identified as a potential target for cell proliferation inhibition. Here we describe the C-terminal region of Net1 as an activator of RNA polymerase I transcription in baker’s yeast. In the absence of this activator RNA polymerase I transcription is downregulated and cell proliferation is strongly impaired. Strikingly, this activator might be conserved in human cells, which points to a general mechanism. Our discovery will help to gain a better understanding of the molecular basis of ribosomal RNA synthesis and may have implications in developing strategies to control cellular growth.
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Affiliation(s)
- Katharina Hannig
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
| | - Virginia Babl
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
| | - Kristin Hergert
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
| | - Andreas Maier
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
| | - Michael Pilsl
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
| | - Christopher Schächner
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
| | - Ulrike Stöckl
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
| | - Philipp Milkereit
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
- * E-mail: (PM); (HT); (WS); (JG)
| | - Herbert Tschochner
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
- * E-mail: (PM); (HT); (WS); (JG)
| | - Wolfgang Seufert
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
- * E-mail: (PM); (HT); (WS); (JG)
| | - Joachim Griesenbeck
- Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, Regensburg, Germany
- * E-mail: (PM); (HT); (WS); (JG)
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25
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Resolution of human ribosomal DNA occurs in anaphase, dependent on tankyrase 1, condensin II, and topoisomerase IIα. Genes Dev 2019; 33:276-281. [PMID: 30804226 PMCID: PMC6411013 DOI: 10.1101/gad.321836.118] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/07/2019] [Indexed: 11/25/2022]
Abstract
In this paper by Daniloski et al., the authors investigated the timing and mechanism of the resolution of the ribosomal DNA (rDNA) repeats during chromosome segregation in human cells. They found that resolution of human rDNA occurs in anaphase after the bulk of the genome, dependent on tankyrase 1, condensin II, and topoisomerase II. Formation of individualized sister chromatids is essential for their accurate segregation. In budding yeast, while most of the genome segregates at the metaphase to anaphase transition, resolution of the ribosomal DNA (rDNA) repeats is delayed. The timing and mechanism in human cells is unknown. Here we show that resolution of human rDNA occurs in anaphase after the bulk of the genome, dependent on tankyrase 1, condensin II, and topoisomerase IIα. Defective resolution leads to rDNA bridges, rDNA damage, and aneuploidy of an rDNA-containing acrocentric chromosome. Thus, temporal regulation of rDNA segregation is conserved between yeast and man and is essential for genome integrity.
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26
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Ramos F, Villoria MT, Alonso-Rodríguez E, Clemente-Blanco A. Role of protein phosphatases PP1, PP2A, PP4 and Cdc14 in the DNA damage response. Cell Stress 2019; 3:70-85. [PMID: 31225502 PMCID: PMC6551743 DOI: 10.15698/cst2019.03.178] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Maintenance of genome integrity is fundamental for cellular physiology. Our hereditary information encoded in the DNA is intrinsically susceptible to suffer variations, mostly due to the constant presence of endogenous and environmental genotoxic stresses. Genomic insults must be repaired to avoid loss or inappropriate transmission of the genetic information, a situation that could lead to the appearance of developmental anomalies and tumorigenesis. To safeguard our genome, cells have evolved a series of mechanisms collectively known as the DNA damage response (DDR). This surveillance system regulates multiple features of the cellular response, including the detection of the lesion, a transient cell cycle arrest and the restoration of the broken DNA molecule. While the role of multiple kinases in the DDR has been well documented over the last years, the intricate roles of protein dephosphorylation have only recently begun to be addressed. In this review, we have compiled recent information about the function of protein phosphatases PP1, PP2A, PP4 and Cdc14 in the DDR, focusing mainly on their capacity to regulate the DNA damage checkpoint and the repair mechanism encompassed in the restoration of a DNA lesion.
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Affiliation(s)
- Facundo Ramos
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| | - María Teresa Villoria
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| | - Esmeralda Alonso-Rodríguez
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
| | - Andrés Clemente-Blanco
- Cell Cycle and Genome Stability Group. Institute of Functional Biology and Genomics (IBFG). Spanish National Research Council (CSIC), University of Salamanca (USAL), C/Zacarías González 2, Salamanca 37007, SPAIN
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27
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Transcription initiation factor TBP: old friend new questions. Biochem Soc Trans 2019; 47:411-423. [DOI: 10.1042/bst20180623] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 01/02/2019] [Accepted: 01/04/2019] [Indexed: 12/14/2022]
Abstract
Abstract
In all domains of life, the regulation of transcription by DNA-dependent RNA polymerases (RNAPs) is achieved at the level of initiation to a large extent. Whereas bacterial promoters are recognized by a σ-factor bound to the RNAP, a complex set of transcription factors that recognize specific promoter elements is employed by archaeal and eukaryotic RNAPs. These initiation factors are of particular interest since the regulation of transcription critically relies on initiation rates and thus formation of pre-initiation complexes. The most conserved initiation factor is the TATA-binding protein (TBP), which is of crucial importance for all archaeal-eukaryotic transcription initiation complexes and the only factor required to achieve full rates of initiation in all three eukaryotic and the archaeal transcription systems. Recent structural, biochemical and genome-wide mapping data that focused on the archaeal and specialized RNAP I and III transcription system showed that the involvement and functional importance of TBP is divergent from the canonical role TBP plays in RNAP II transcription. Here, we review the role of TBP in the different transcription systems including a TBP-centric discussion of archaeal and eukaryotic initiation complexes. We furthermore highlight questions concerning the function of TBP that arise from these findings.
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28
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Abstract
The nucleolus is a membraneless organelle of the nucleus and the site of rRNA synthesis, maturation, and assembly into preribosomal particles. The nucleolus, organized around arrays of rRNA genes (rDNA), dissolves during prophase of mitosis in metazoans, when rDNA transcription ceases, and reforms in telophase, when rDNA transcription resumes. No such dissolution and reformation cycle exists in budding yeast, and the precise course of nucleolar segregation remains unclear. By quantitative live-cell imaging, we observed that the yeast nucleolus is reorganized in its protein composition during mitosis. Daughter cells received equal shares of preinitiation factors, which bind the RNA polymerase I promoter and the rDNA binding barrier protein Fob1, but only about one-third of RNA polymerase I and the processing factors Nop56 and Nsr1. The distribution bias was diminished in nonpolar chromosome segregation events observable in dyn1 mutants. Unequal distribution, however, was enhanced by defects in RNA polymerase I, suggesting that rDNA transcription supports nucleolar segregation. Indeed, quantification of pre-rRNA levels indicated ongoing rDNA transcription in yeast mitosis. These data, together with photobleaching experiments to measure nucleolar protein dynamics in anaphase, consolidate a model that explains the differential partitioning of nucleolar components in budding yeast mitosis.
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Affiliation(s)
- Philipp Girke
- Department of Genetics, University of Regensburg, D-93040 Regensburg, Germany
| | - Wolfgang Seufert
- Department of Genetics, University of Regensburg, D-93040 Regensburg, Germany
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29
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Condensin action and compaction. Curr Genet 2018; 65:407-415. [PMID: 30361853 DOI: 10.1007/s00294-018-0899-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 10/18/2018] [Accepted: 10/20/2018] [Indexed: 12/20/2022]
Abstract
Condensin is a multi-subunit protein complex that belongs to the family of structural maintenance of chromosomes (SMC) complexes. Condensins regulate chromosome structure in a wide range of processes including chromosome segregation, gene regulation, DNA repair and recombination. Recent research defined the structural features and molecular activities of condensins, but it is unclear how these activities are connected to the multitude of phenotypes and functions attributed to condensins. In this review, we briefly discuss the different molecular mechanisms by which condensins may regulate global chromosome compaction, organization of topologically associated domains, clustering of specific loci such as tRNA genes, rDNA segregation, and gene regulation.
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30
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Neitzel LR, Broadus MR, Zhang N, Sawyer L, Wallace HA, Merkle JA, Jodoin JN, Sitaram P, Crispi EE, Rork W, Lee LA, Pan D, Gould KL, Page-McCaw A, Lee E. Characterization of a cdc14 null allele in Drosophila melanogaster. Biol Open 2018; 7:bio.035394. [PMID: 29945873 PMCID: PMC6078348 DOI: 10.1242/bio.035394] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cdc14 is an evolutionarily conserved serine/threonine phosphatase. Originally identified in Saccharomyces cerevisiae as a cell cycle regulator, its role in other eukaryotic organisms remains unclear. In Drosophila melanogaster, Cdc14 is encoded by a single gene, thus facilitating its study. We found that Cdc14 expression is highest in the testis of adult flies and that cdc14 null flies are viable. cdc14 null female and male flies do not display altered fertility. cdc14 null males, however, exhibit decreased sperm competitiveness. Previous studies have shown that Cdc14 plays a role in ciliogenesis during zebrafish development. In Drosophila, sensory neurons are ciliated. We found that the Drosophila cdc14 null mutants have defects in chemosensation and mechanosensation as indicated by decreased avoidance of repellant substances and decreased response to touch. In addition, we show that cdc14 null mutants have defects in lipid metabolism and resistance to starvation. These studies highlight the diversity of Cdc14 function in eukaryotes despite its structural conservation. Summary: The Cdc14 phosphatase has been implicated in cell cycle regulation in S. cerevisiae. We show that Drosophila cdc14 mutants are viable, but exhibit defects in sperm competition, chemosensation, and mechanosensation.
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Affiliation(s)
- Leif R Neitzel
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Program in Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Matthew R Broadus
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Nailing Zhang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Leah Sawyer
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Heather A Wallace
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Division of Genetics, Brigham and Women's Hospital, Boston, MA 02115, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Julie A Merkle
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jeanne N Jodoin
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Poojitha Sitaram
- Department of Microbiology, New York University Langone Medical Center, New York, NY 10016, USA
| | - Emily E Crispi
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - William Rork
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Laura A Lee
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Duojia Pan
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Kathleen L Gould
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Andrea Page-McCaw
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA .,Program in Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Ethan Lee
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA .,Program in Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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31
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Engel C, Neyer S, Cramer P. Distinct Mechanisms of Transcription Initiation by RNA Polymerases I and II. Annu Rev Biophys 2018; 47:425-446. [DOI: 10.1146/annurev-biophys-070317-033058] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RNA polymerases I and II (Pol I and Pol II) are the eukaryotic enzymes that catalyze DNA-dependent synthesis of ribosomal RNA and messenger RNA, respectively. Recent work shows that the transcribing forms of both enzymes are similar and the fundamental mechanisms of RNA chain elongation are conserved. However, the mechanisms of transcription initiation and its regulation differ between Pol I and Pol II. Recent structural studies of Pol I complexes with transcription initiation factors provided insights into how the polymerase recognizes its specific promoter DNA, how it may open DNA, and how initiation may be regulated. Comparison with the well-studied Pol II initiation system reveals a distinct architecture of the initiation complex and visualizes promoter- and gene-class-specific aspects of transcription initiation. On the basis of new structural studies, we derive a model of the Pol I transcription cycle and provide a molecular movie of Pol I transcription that can be used for teaching.
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Affiliation(s)
- Christoph Engel
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
- Current affiliation: Institute of Biochemistry, Genetics and Microbiology, University of Regensburg, 93053 Regensburg, Germany
| | - Simon Neyer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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32
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Matos-Perdomo E, Machín F. The ribosomal DNA metaphase loop of Saccharomyces cerevisiae gets condensed upon heat stress in a Cdc14-independent TORC1-dependent manner. Cell Cycle 2018; 17:200-215. [PMID: 29166821 PMCID: PMC5884360 DOI: 10.1080/15384101.2017.1407890] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Chromosome morphology in Saccharomyces cerevisiae is only visible at the microscopic level in the ribosomal DNA array (rDNA). The rDNA has been thus used as a model to characterize condensation and segregation of sister chromatids in mitosis. It has been established that the metaphase structure ("loop") depends, among others, on the condensin complex; whereas its segregation also depends on that complex, the Polo-like kinase Cdc5 and the cell cycle master phosphatase Cdc14. In addition, Cdc14 also drives rDNA hypercondensation in telophase. Remarkably, since all these components are essential for cell survival, their role on rDNA condensation and segregation was established by temperature-sensitive (ts) alleles. Here, we show that the heat stress (HS) used to inactivate ts alleles (25 ºC to 37 ºC shift) causes rDNA loop condensation in metaphase-arrested wild type cells, a result that can also be mimicked by other stresses that inhibit the TORC1 pathway. Because this condensation might challenge previous findings with ts alleles, we have repeated classical experiments of rDNA condensation and segregation, yet using instead auxin-driven degradation alleles (aid alleles). We have undertaken the protein degradation at lower temperatures (25 ºC) and concluded that the classical roles for condensin, Cdc5, Cdc14 and Cdc15 still prevailed. Thus, condensin degradation disrupts rDNA higher organization, Cdc14 and Cdc5 degradation precludes rDNA segregation and Cdc15 degradation still allows rDNA hypercompaction in telophase. Finally, we provide direct genetic evidence that this HS-mediated rDNA condensation is dependent on TORC1 but, unlike the one observed in anaphase, is independent of Cdc14.
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Affiliation(s)
- Emiliano Matos-Perdomo
- a Unidad de Investigación , Hospital Universitario Ntra Sra de Candelaria , Ctra del Rosario 145, 38010 , Santa Cruz de Tenerife , Spain.,b Universidad de La Laguna , Tenerife , Spain
| | - Félix Machín
- a Unidad de Investigación , Hospital Universitario Ntra Sra de Candelaria , Ctra del Rosario 145, 38010 , Santa Cruz de Tenerife , Spain
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33
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Ramos F, Leonard J, Clemente-Blanco A, Aragón L. Cdc14 and Chromosome Condensation: Evaluation of the Recruitment of Condensin to Genomic Regions. Methods Mol Biol 2018; 1505:229-243. [PMID: 27826868 DOI: 10.1007/978-1-4939-6502-1_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Chromosome condensation is an essential morphological event required for successful DNA segregation during mitosis. The high level of genome compaction achieved during this process is attained by the evolutionary conserved condensin complex. Recently, several lines of evidences have demonstrated that the mitotic phosphatase Cdc14 is required to ensure condensin loading onto chromosomes. To date several approaches have been used in order to characterize condensin activity and regulation, however these techniques are time-consuming and require complex equipment. In this chapter we described an easy and reliable protocol to analyze Cdc14-dependent condensin loading onto specific genomic DNA regions by using a chromatin immunoprecipitation (ChIP) technique.
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Affiliation(s)
- Facundo Ramos
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca (USAL), C/ Zacarías González 2, Salamanca, 37007, Spain
| | - Joanne Leonard
- Cell Cycle Group, Medical Research Council, Clinical Sciences Centre, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Andrés Clemente-Blanco
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca (USAL), C/ Zacarías González 2, Salamanca, 37007, Spain
| | - Luis Aragón
- Cell Cycle Group, Medical Research Council, Clinical Sciences Centre, Imperial College London, Du Cane Road, London, W12 0NN, UK.
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34
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Sarlós K, Biebricher A, Petermann EJG, Wuite GJL, Hickson ID. Knotty Problems during Mitosis: Mechanistic Insight into the Processing of Ultrafine DNA Bridges in Anaphase. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2017; 82:187-195. [PMID: 29167280 DOI: 10.1101/sqb.2017.82.033647] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
To survive and proliferate, cells have to faithfully segregate their newly replicated genomic DNA to the two daughter cells. However, the sister chromatids of mitotic chromosomes are frequently interlinked by so-called ultrafine DNA bridges (UFBs) that are visible in the anaphase of mitosis. UFBs can only be detected by the proteins bound to them and not by staining with conventional DNA dyes. These DNA bridges are presumed to represent entangled sister chromatids and hence pose a threat to faithful segregation. A failure to accurately unlink UFB DNA results in chromosome segregation errors and binucleation. This, in turn, compromises genome integrity, which is a hallmark of cancer. UFBs are actively removed during anaphase, and most known UFB-associated proteins are enzymes involved in DNA repair in interphase. However, little is known about the mitotic activities of these enzymes or the exact DNA structures present on UFBs. We focus on the biology of UFBs, with special emphasis on their underlying DNA structure and the decatenation machineries that process UFBs.
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Affiliation(s)
- Kata Sarlós
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Andreas Biebricher
- Department of Physics and Astronomy and LaserLab, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Erwin J G Petermann
- Department of Physics and Astronomy and LaserLab, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Gijs J L Wuite
- Department of Physics and Astronomy and LaserLab, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Ian D Hickson
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
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35
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Abstract
The nucleolus in Saccharomyces cerevisiae is one of the last genomic regions to be condensed in mitosis. A new study shows that this extended nucleolar relaxation state is fundamental for the timely execution of mitotic exit.
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36
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de Los Santos-Velázquez AI, de Oya IG, Manzano-López J, Monje-Casas F. Late rDNA Condensation Ensures Timely Cdc14 Release and Coordination of Mitotic Exit Signaling with Nucleolar Segregation. Curr Biol 2017; 27:3248-3263.e5. [PMID: 29056450 DOI: 10.1016/j.cub.2017.09.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/16/2017] [Accepted: 09/13/2017] [Indexed: 12/28/2022]
Abstract
The nucleolus plays a pivotal role in multiple key cellular processes. An illustrative example is the regulation of mitotic exit in Saccharomyces cerevisiae through the nucleolar sequestration of the Cdc14 phosphatase. The peculiar structure of the nucleolus, however, has also its drawbacks. The repetitive nature of the rDNA gives rise to cohesion-independent linkages whose resolution in budding yeast requires the Cdc14-dependent inhibition of rRNA transcription, which facilitates condensin accessibility to this locus. Thus, the rDNA condenses and segregates later than most other yeast genomic regions. Here, we show that defective function of a small nucleolar ribonucleoprotein particle (snoRNP) assembly factor facilitates condensin accessibility to the rDNA and induces nucleolar hyper-condensation. Interestingly, this increased compaction of the nucleolus interferes with the proper release of Cdc14 from this organelle. This observation provides an explanation for the delayed rDNA condensation in budding yeast, which is necessary to efficiently coordinate timely Cdc14 release and mitotic exit with nucleolar compaction and segregation.
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Affiliation(s)
- Ana Isabel de Los Santos-Velázquez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Spanish National Research Council (CSIC), University of Seville, and University Pablo de Olavide, Avda. Américo Vespucio 24, 41092 Sevilla, Spain
| | - Inés G de Oya
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Spanish National Research Council (CSIC), University of Seville, and University Pablo de Olavide, Avda. Américo Vespucio 24, 41092 Sevilla, Spain
| | - Javier Manzano-López
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Spanish National Research Council (CSIC), University of Seville, and University Pablo de Olavide, Avda. Américo Vespucio 24, 41092 Sevilla, Spain
| | - Fernando Monje-Casas
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Spanish National Research Council (CSIC), University of Seville, and University Pablo de Olavide, Avda. Américo Vespucio 24, 41092 Sevilla, Spain.
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37
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Mathew V, Tam AS, Milbury KL, Hofmann AK, Hughes CS, Morin GB, Loewen CJR, Stirling PC. Selective aggregation of the splicing factor Hsh155 suppresses splicing upon genotoxic stress. J Cell Biol 2017; 216:4027-4040. [PMID: 28978642 PMCID: PMC5716266 DOI: 10.1083/jcb.201612018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 07/17/2017] [Accepted: 08/22/2017] [Indexed: 12/15/2022] Open
Abstract
Upon genotoxic stress, dynamic relocalization events control DNA repair as well as alterations of the transcriptome and proteome, enabling stress recovery. How these events may influence one another is only partly known. Beginning with a cytological screen of genome stability proteins, we find that the splicing factor Hsh155 disassembles from its partners and localizes to both intranuclear and cytoplasmic protein quality control (PQC) aggregates under alkylation stress. Aggregate sequestration of Hsh155 occurs at nuclear and then cytoplasmic sites in a manner that is regulated by molecular chaperones and requires TORC1 activity signaling through the Sfp1 transcription factor. This dynamic behavior is associated with intron retention in ribosomal protein gene transcripts, a decrease in splicing efficiency, and more rapid recovery from stress. Collectively, our analyses suggest a model in which some proteins evicted from chromatin and undergoing transcriptional remodeling during stress are targeted to PQC sites to influence gene expression changes and facilitate stress recovery.
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Affiliation(s)
- Veena Mathew
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada
| | - Annie S Tam
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| | - Karissa L Milbury
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada
| | - Analise K Hofmann
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Christopher S Hughes
- Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, Canada
| | - Gregg B Morin
- Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| | - Christopher J R Loewen
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Peter C Stirling
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada .,Department of Medical Genetics, University of British Columbia, Vancouver, Canada
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38
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Lazar-Stefanita L, Scolari VF, Mercy G, Muller H, Guérin TM, Thierry A, Mozziconacci J, Koszul R. Cohesins and condensins orchestrate the 4D dynamics of yeast chromosomes during the cell cycle. EMBO J 2017; 36:2684-2697. [PMID: 28729434 PMCID: PMC5599795 DOI: 10.15252/embj.201797342] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 06/29/2017] [Accepted: 07/04/2017] [Indexed: 11/09/2022] Open
Abstract
Duplication and segregation of chromosomes involves dynamic reorganization of their internal structure by conserved architectural proteins, including the structural maintenance of chromosomes (SMC) complexes cohesin and condensin. Despite active investigation of the roles of these factors, a genome-wide view of dynamic chromosome architecture at both small and large scale during cell division is still missing. Here, we report the first comprehensive 4D analysis of the higher-order organization of the Saccharomyces cerevisiae genome throughout the cell cycle and investigate the roles of SMC complexes in controlling structural transitions. During replication, cohesion establishment promotes numerous long-range intra-chromosomal contacts and correlates with the individualization of chromosomes, which culminates at metaphase. In anaphase, mitotic chromosomes are abruptly reorganized depending on mechanical forces exerted by the mitotic spindle. Formation of a condensin-dependent loop bridging the centromere cluster with the rDNA loci suggests that condensin-mediated forces may also directly facilitate segregation. This work therefore comprehensively recapitulates cell cycle-dependent chromosome dynamics in a unicellular eukaryote, but also unveils new features of chromosome structural reorganization during highly conserved stages of cell division.
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Affiliation(s)
- Luciana Lazar-Stefanita
- Institut Pasteur, Department Genomes and Genetics, Unité Régulation Spatiale des Génomes, Paris, France
- CNRS, UMR 3525, Paris, France
- Institut Pasteur, CNRS Center of Bioinformatics, Biostatistics and Integrative Biology (C3BI), USR 3756, Paris, France
- Sorbonne Universités, UPMC Université Paris 6, Complexité du Vivant, Paris, France
| | - Vittore F Scolari
- Institut Pasteur, Department Genomes and Genetics, Unité Régulation Spatiale des Génomes, Paris, France
- CNRS, UMR 3525, Paris, France
- Institut Pasteur, CNRS Center of Bioinformatics, Biostatistics and Integrative Biology (C3BI), USR 3756, Paris, France
| | - Guillaume Mercy
- Institut Pasteur, Department Genomes and Genetics, Unité Régulation Spatiale des Génomes, Paris, France
- CNRS, UMR 3525, Paris, France
- Institut Pasteur, CNRS Center of Bioinformatics, Biostatistics and Integrative Biology (C3BI), USR 3756, Paris, France
- Sorbonne Universités, UPMC Université Paris 6, Complexité du Vivant, Paris, France
| | - Héloise Muller
- Institut Pasteur, Department Genomes and Genetics, Unité Régulation Spatiale des Génomes, Paris, France
- CNRS, UMR 3525, Paris, France
- Institut Pasteur, CNRS Center of Bioinformatics, Biostatistics and Integrative Biology (C3BI), USR 3756, Paris, France
| | - Thomas M Guérin
- Laboratoire Télomères et Réparation du Chromosome, CEA, INSERM, UMR 967, IRCM, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Agnès Thierry
- Institut Pasteur, Department Genomes and Genetics, Unité Régulation Spatiale des Génomes, Paris, France
- CNRS, UMR 3525, Paris, France
- Institut Pasteur, CNRS Center of Bioinformatics, Biostatistics and Integrative Biology (C3BI), USR 3756, Paris, France
| | - Julien Mozziconacci
- Sorbonne Universités, Theoretical Physics for Condensed Matter Lab, UPMC Université Paris 06, Paris, France
- CNRS, UMR 7600, Paris, France
| | - Romain Koszul
- Institut Pasteur, Department Genomes and Genetics, Unité Régulation Spatiale des Génomes, Paris, France
- CNRS, UMR 3525, Paris, France
- Institut Pasteur, CNRS Center of Bioinformatics, Biostatistics and Integrative Biology (C3BI), USR 3756, Paris, France
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39
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Schalbetter SA, Goloborodko A, Fudenberg G, Belton JM, Miles C, Yu M, Dekker J, Mirny L, Baxter J. SMC complexes differentially compact mitotic chromosomes according to genomic context. Nat Cell Biol 2017; 19:1071-1080. [PMID: 28825700 PMCID: PMC5640152 DOI: 10.1038/ncb3594] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 07/19/2017] [Indexed: 12/26/2022]
Abstract
Structural maintenance of chromosomes (SMC) protein complexes are key determinants of chromosome conformation. Using Hi-C and polymer modelling, we study how cohesin and condensin, two deeply conserved SMC complexes, organize chromosomes in the budding yeast Saccharomyces cerevisiae. The canonical role of cohesin is to co-align sister chromatids, while condensin generally compacts mitotic chromosomes. We find strikingly different roles for the two complexes in budding yeast mitosis. First, cohesin is responsible for compacting mitotic chromosome arms, independently of sister chromatid cohesion. Polymer simulations demonstrate that this role can be fully accounted for through cis-looping of chromatin. Second, condensin is generally dispensable for compaction along chromosome arms. Instead, it plays a targeted role compacting the rDNA proximal regions and promoting resolution of peri-centromeric regions. Our results argue that the conserved mechanism of SMC complexes is to form chromatin loops and that distinct SMC-dependent looping activities are selectively deployed to appropriately compact chromosomes.
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MESH Headings
- Adenosine Triphosphatases/genetics
- Adenosine Triphosphatases/metabolism
- Cell Cycle Proteins/genetics
- Cell Cycle Proteins/metabolism
- Chromatin/chemistry
- Chromatin/genetics
- Chromatin/metabolism
- Chromatin Assembly and Disassembly
- Chromosomal Proteins, Non-Histone/genetics
- Chromosomal Proteins, Non-Histone/metabolism
- Chromosome Structures
- Chromosomes, Fungal/chemistry
- Chromosomes, Fungal/genetics
- Chromosomes, Fungal/metabolism
- Computer Simulation
- DNA, Fungal/chemistry
- DNA, Fungal/genetics
- DNA, Fungal/metabolism
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- DNA, Ribosomal/metabolism
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Mitosis
- Models, Genetic
- Models, Molecular
- Multiprotein Complexes/genetics
- Multiprotein Complexes/metabolism
- Nucleic Acid Conformation
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/growth & development
- Saccharomyces cerevisiae/metabolism
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Structure-Activity Relationship
- Cohesins
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Affiliation(s)
| | - Anton Goloborodko
- Institute for Medical Engineering and Sciences, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Geoffrey Fudenberg
- Institute for Medical Engineering and Sciences, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jon-Matthew Belton
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Catrina Miles
- Genome Damage and Stability Centre, Science Park Road, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Miao Yu
- Genome Damage and Stability Centre, Science Park Road, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Job Dekker
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Leonid Mirny
- Institute for Medical Engineering and Sciences, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jonathan Baxter
- Genome Damage and Stability Centre, Science Park Road, University of Sussex, Falmer, Brighton BN1 9RQ, UK
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40
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Moriggi G, Gaspar SG, Nieto B, Bustelo XR, Dosil M. Focal accumulation of preribosomes outside the nucleolus during metaphase-anaphase in budding yeast. RNA (NEW YORK, N.Y.) 2017; 23:1432-1443. [PMID: 28588079 PMCID: PMC5558912 DOI: 10.1261/rna.061259.117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/30/2017] [Indexed: 06/07/2023]
Abstract
Saccharomyces cerevisiae contains one nucleolus that remains intact in the mother-cell side of the nucleus throughout most of mitosis. Based on this, it is assumed that the bulk of ribosome production during cell division occurs in the mother cell. Here, we show that the ribosome synthesis machinery localizes not only in the nucleolus but also at a center that is present in the bud side of the nucleus after the initiation of mitosis. This center can be visualized by live microscopy as a punctate body located in close proximity to the nuclear envelope and opposite to the nucleolus. It contains ribosomal DNA (rDNA) and precursors of both 40S and 60S ribosomal subunits. Proteins that actively participate in ribosome synthesis, but not functionally defective variants, accumulate in that site. The formation of this body occurs in the metaphase-to-anaphase transition when discrete regions of rDNA occasionally exit the nucleolus and move into the bud. Collectively, our data unveil the existence of a previously unknown mechanism for preribosome accumulation at the nuclear periphery in budding yeast. We propose that this might be a strategy to expedite the delivery of ribosomes to the growing bud.
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Affiliation(s)
- Giulia Moriggi
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, CSIC-University of Salamanca, 37007 Salamanca, Spain
| | - Sonia G Gaspar
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, CSIC-University of Salamanca, 37007 Salamanca, Spain
| | - Blanca Nieto
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, CSIC-University of Salamanca, 37007 Salamanca, Spain
| | - Xosé R Bustelo
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, CSIC-University of Salamanca, 37007 Salamanca, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Centro de Investigación del Cáncer, 37007 Salamanca, Spain
| | - Mercedes Dosil
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, CSIC-University of Salamanca, 37007 Salamanca, Spain
- Departamento de Bioquímica y Biología Molecular, University of Salamanca, 37007 Salamanca, Spain
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41
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Kobayashi J, Matsuura Y. Structure and dimerization of the catalytic domain of the protein phosphatase Cdc14p, a key regulator of mitotic exit in Saccharomyces cerevisiae. Protein Sci 2017; 26:2105-2112. [PMID: 28758351 DOI: 10.1002/pro.3244] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 07/19/2017] [Accepted: 07/20/2017] [Indexed: 01/31/2023]
Abstract
In the budding yeast Saccharomyces cerevisiae, the protein phosphatase Cdc14p orchestrates various events essential for mitotic exit. We have determined the X-ray crystal structures at 1.85 Å resolution of the catalytic domain of Cdc14p in both the apo state, and as a complex with S160-phosphorylated Swi6p peptide. Each asymmetric unit contains two Cdc14p chains arranged in an intimately associated homodimer, consistent with its oligomeric state in solution. The dimerization interface is located on the backside of the substrate-binding cleft. Structure-based mutational analyses indicate that the dimerization of Cdc14p is required for normal growth of yeast cells.
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Affiliation(s)
| | - Yoshiyuki Matsuura
- Division of Biological Science, Nagoya University, Japan.,Structural Biology Research Center, Graduate School of Science, Nagoya University, Japan
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42
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The Nuts and Bolts of Transcriptionally Silent Chromatin in Saccharomyces cerevisiae. Genetics 2017; 203:1563-99. [PMID: 27516616 DOI: 10.1534/genetics.112.145243] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/30/2016] [Indexed: 12/31/2022] Open
Abstract
Transcriptional silencing in Saccharomyces cerevisiae occurs at several genomic sites including the silent mating-type loci, telomeres, and the ribosomal DNA (rDNA) tandem array. Epigenetic silencing at each of these domains is characterized by the absence of nearly all histone modifications, including most prominently the lack of histone H4 lysine 16 acetylation. In all cases, silencing requires Sir2, a highly-conserved NAD(+)-dependent histone deacetylase. At locations other than the rDNA, silencing also requires additional Sir proteins, Sir1, Sir3, and Sir4 that together form a repressive heterochromatin-like structure termed silent chromatin. The mechanisms of silent chromatin establishment, maintenance, and inheritance have been investigated extensively over the last 25 years, and these studies have revealed numerous paradigms for transcriptional repression, chromatin organization, and epigenetic gene regulation. Studies of Sir2-dependent silencing at the rDNA have also contributed to understanding the mechanisms for maintaining the stability of repetitive DNA and regulating replicative cell aging. The goal of this comprehensive review is to distill a wide array of biochemical, molecular genetic, cell biological, and genomics studies down to the "nuts and bolts" of silent chromatin and the processes that yield transcriptional silencing.
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43
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Abstract
Chromatin condensation during mitosis produces detangled and discrete DNA entities required for high fidelity sister chromatid segregation during mitosis and positions DNA away from the cleavage furrow during cytokinesis. Regional condensation during G1 also establishes a nuclear architecture through which gene transcription is regulated but remains plastic so that cells can respond to changes in nutrient levels, temperature and signaling molecules. To date, however, the potential impact of this plasticity on mitotic chromosome condensation remains unknown. Here, we report results obtained from a new condensation assay that wildtype budding yeast cells exhibit dramatic changes in rDNA conformation in response to temperature. rDNA hypercondenses in wildtype cells maintained at 37°C, compared with cells maintained at 23°C. This hypercondensation machinery can be activated during preanaphase but readily inactivated upon exposure to lower temperatures. Extended mitotic arrest at 23°C does not result in hypercondensation, negating a kinetic-based argument in which condensation that typically proceeds slowly is accelerated when cells are placed at 37°C. Neither elevated recombination nor reduced transcription appear to promote this hypercondensation. This heretofore undetected temperature-dependent hypercondensation pathway impacts current views of chromatin structure based on conditional mutant gene analyses and significantly extends our understanding of physiologic changes in chromatin architecture in response to hypothermia.
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Affiliation(s)
- Donglai Shen
- a Department of Biological Sciences , Lehigh University , Bethlehem , PA , USA
| | - Robert V Skibbens
- a Department of Biological Sciences , Lehigh University , Bethlehem , PA , USA
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44
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Abstract
The Mitotic Exit Network (MEN) is an essential signaling pathway, closely related to the Hippo pathway in mammals, which promotes mitotic exit and initiates cytokinesis in the budding yeast Saccharomyces cerevisiae. Here, we summarize the current knowledge about the MEN components and their regulation.
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Affiliation(s)
- Bàrbara Baro
- Department of Pediatrics, Division of Infectious Diseases,Stanford University School of Medicine, Stanford, CA, USA.
| | - Ethel Queralt
- Cancer Epigenetics & Biology Program, Hospitalet de Llobregat, Barcelona, Spain.
| | - Fernando Monje-Casas
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio, s/n. P.C.T. Cartuja 93., 41092, Sevilla, Spain.
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45
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The loading of condensin in the context of chromatin. Curr Genet 2016; 63:577-589. [PMID: 27909798 DOI: 10.1007/s00294-016-0669-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 11/24/2016] [Accepted: 11/25/2016] [Indexed: 12/23/2022]
Abstract
The packaging of DNA into chromosomes is a ubiquitous process that enables living organisms to structure and transmit their genome accurately through cell divisions. In the three kingdoms of life, the architecture and dynamics of chromosomes rely upon ring-shaped SMC (Structural Maintenance of Chromosomes) condensin complexes. To understand how condensin rings organize chromosomes, it is essential to decipher how they associate with chromatin filaments. Here, we use recent evidence to discuss the role played by nucleosomes and transcription factors in the loading of condensin at transcribed genes. We propose a model whereby cis-acting features nestled in the promoters of active genes synergistically attract condensin rings and promote their association with DNA.
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46
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Villoria MT, Ramos F, Dueñas E, Faull P, Cutillas PR, Clemente-Blanco A. Stabilization of the metaphase spindle by Cdc14 is required for recombinational DNA repair. EMBO J 2016; 36:79-101. [PMID: 27852625 PMCID: PMC5210157 DOI: 10.15252/embj.201593540] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 10/05/2016] [Accepted: 10/18/2016] [Indexed: 11/24/2022] Open
Abstract
Cells are constantly threatened by multiple sources of genotoxic stress that cause DNA damage. To maintain genome integrity, cells have developed a coordinated signalling network called DNA damage response (DDR). While multiple kinases have been thoroughly studied during DDR activation, the role of protein dephosphorylation in the damage response remains elusive. Here, we show that the phosphatase Cdc14 is essential to fulfil recombinational DNA repair in budding yeast. After DNA double‐strand break (DSB) generation, Cdc14 is transiently released from the nucleolus and activated. In this state, Cdc14 targets the spindle pole body (SPB) component Spc110 to counterbalance its phosphorylation by cyclin‐dependent kinase (Cdk). Alterations in the Cdk/Cdc14‐dependent phosphorylation status of Spc110, or its inactivation during the induction of a DNA lesion, generate abnormal oscillatory SPB movements that disrupt DSB‐SPB interactions. Remarkably, these defects impair DNA repair by homologous recombination indicating that SPB integrity is essential during the repair process. Together, these results show that Cdc14 promotes spindle stability and DSB‐SPB tethering during DNA repair, and imply that metaphase spindle maintenance is a critical feature of the repair process.
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Affiliation(s)
- María Teresa Villoria
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica Consejo Superior de Investigaciones Científicas (CSIC) Universidad de Salamanca (USAL), Salamanca, Spain
| | - Facundo Ramos
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica Consejo Superior de Investigaciones Científicas (CSIC) Universidad de Salamanca (USAL), Salamanca, Spain
| | - Encarnación Dueñas
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica Consejo Superior de Investigaciones Científicas (CSIC) Universidad de Salamanca (USAL), Salamanca, Spain
| | - Peter Faull
- Biological Mass Spectrometry and Proteomics Laboratory, Medical Research Council Clinical Science Centre Imperial College, London, UK
| | - Pedro Rodríguez Cutillas
- Biological Mass Spectrometry and Proteomics Laboratory, Medical Research Council Clinical Science Centre Imperial College, London, UK
| | - Andrés Clemente-Blanco
- Cell Cycle and Genome Stability Group, Instituto de Biología Funcional y Genómica Consejo Superior de Investigaciones Científicas (CSIC) Universidad de Salamanca (USAL), Salamanca, Spain
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47
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Nielsen CF, Hickson ID. PICH promotes mitotic chromosome segregation: Identification of a novel role in rDNA disjunction. Cell Cycle 2016; 15:2704-11. [PMID: 27565185 DOI: 10.1080/15384101.2016.1222336] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
PICH is an SNF2-family DNA translocase that appears to play a role specifically in mitosis. Characterization of PICH in human cells led to the initial discovery of "ultra-fine DNA bridges" (UFBs) that connect the 2 segregating DNA masses in the anaphase of mitosis. These bridge structures, which arise from specific regions of the genome, are a normal feature of anaphase but had escaped detection previously because they do not stain with commonly used DNA dyes. Nevertheless, UFBs are important for genome maintenance because defects in UFB resolution can lead to cytokinesis failure. We reported recently that PICH stimulates the unlinking (decatenation) of entangled DNA by Topoisomerase IIα (Topo IIα), and is important for the resolution of UFBs. We also demonstrated that PICH and Topo IIα co-localize at the rDNA (rDNA). In this Extra View article, we discuss the mitotic roles of PICH and explore further the role of PICH in the timely segregation of the rDNA locus.
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Affiliation(s)
- Christian F Nielsen
- a Center for Chromosome Stability , Department of Cellular and Molecular Medicine , University of Copenhagen , Copenhagen , Denmark.,b Chromosome Research, Murdoch Children's Research Institute, Royal Children's Hospital , Parkville , VIC , Australia
| | - Ian D Hickson
- a Center for Chromosome Stability , Department of Cellular and Molecular Medicine , University of Copenhagen , Copenhagen , Denmark
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48
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Abstract
Nucleoli form around tandem arrays of a ribosomal gene repeat, termed nucleolar organizer regions (NORs). During metaphase, active NORs adopt a characteristic undercondensed morphology. Recent evidence indicates that the HMG-box-containing DNA-binding protein UBF (upstream binding factor) is directly responsible for this morphology and provides a mitotic bookmark to ensure rapid nucleolar formation beginning in telophase in human cells. This is likely to be a widely employed strategy, as UBF is present throughout metazoans. In higher eukaryotes, NORs are typically located within regions of chromosomes that form perinucleolar heterochromatin during interphase. Typically, the genomic architecture of NORs and the chromosomal regions within which they lie is very poorly described, yet recent evidence points to a role for context in their function. In Arabidopsis, NOR silencing appears to be controlled by sequences outside the rDNA (ribosomal DNA) array. Translocations reveal a role for context in the expression of the NOR on the X chromosome in Drosophila Recent work has begun on characterizing the genomic architecture of human NORs. A role for distal sequences located in perinucleolar heterochromatin has been inferred, as they exhibit a complex transcriptionally active chromatin structure. Links between rDNA genomic stability and aging in Saccharomyces cerevisiae are now well established, and indications are emerging that this is important in aging and replicative senescence in higher eukaryotes. This, combined with the fact that rDNA arrays are recombinational hot spots in cancer cells, has focused attention on DNA damage responses in NORs. The introduction of DNA double-strand breaks into rDNA arrays leads to a dramatic reorganization of nucleolar structure. Damaged rDNA repeats move from the nucleolar interior to form caps at the nucleolar periphery, presumably to facilitate repair, suggesting that the chromosomal context of human NORs contributes to their genomic stability. The inclusion of NORs and their surrounding chromosomal environments in future genome drafts now becomes a priority.
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Affiliation(s)
- Brian McStay
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland, Galway, Ireland
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49
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Toselli-Mollereau E, Robellet X, Fauque L, Lemaire S, Schiklenk C, Klein C, Hocquet C, Legros P, N'Guyen L, Mouillard L, Chautard E, Auboeuf D, Haering CH, Bernard P. Nucleosome eviction in mitosis assists condensin loading and chromosome condensation. EMBO J 2016; 35:1565-81. [PMID: 27266525 DOI: 10.15252/embj.201592849] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 05/05/2016] [Indexed: 12/15/2022] Open
Abstract
Condensins associate with DNA and shape mitotic chromosomes. Condensins are enriched nearby highly expressed genes during mitosis, but how this binding is achieved and what features associated with transcription attract condensins remain unclear. Here, we report that condensin accumulates at or in the immediate vicinity of nucleosome-depleted regions during fission yeast mitosis. Two transcriptional coactivators, the Gcn5 histone acetyltransferase and the RSC chromatin-remodelling complex, bind to promoters adjoining condensin-binding sites and locally evict nucleosomes to facilitate condensin binding and allow efficient mitotic chromosome condensation. The function of Gcn5 is closely linked to condensin positioning, since neither the localization of topoisomerase II nor that of the cohesin loader Mis4 is altered in gcn5 mutant cells. We propose that nucleosomes act as a barrier for the initial binding of condensin and that nucleosome-depleted regions formed at highly expressed genes by transcriptional coactivators constitute access points into chromosomes where condensin binds free genomic DNA.
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Affiliation(s)
- Esther Toselli-Mollereau
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Xavier Robellet
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Lydia Fauque
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Sébastien Lemaire
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | | | - Carlo Klein
- Cell Biology and Biophysics Unit, EMBL, Heidelberg, Germany
| | - Clémence Hocquet
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Pénélope Legros
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Lia N'Guyen
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Léo Mouillard
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Emilie Chautard
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | - Didier Auboeuf
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
| | | | - Pascal Bernard
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Lyon, France
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50
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Condensin targets and reduces unwound DNA structures associated with transcription in mitotic chromosome condensation. Nat Commun 2015. [PMID: 26204128 PMCID: PMC4525155 DOI: 10.1038/ncomms8815] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Chromosome condensation is a hallmark of mitosis in eukaryotes and is a prerequisite for faithful segregation of genetic material to daughter cells. Here we show that condensin, which is essential for assembling condensed chromosomes, helps to preclude the detrimental effects of gene transcription on mitotic condensation. ChIP-seq profiling reveals that the fission yeast condensin preferentially binds to active protein-coding genes in a transcription-dependent manner during mitosis. Pharmacological and genetic attenuation of transcription largely rescue bulk chromosome segregation defects observed in condensin mutants. We also demonstrate that condensin is associated with and reduces unwound DNA segments generated by transcription, providing a direct link between an in vitro activity of condensin and its in vivo function. The human condensin isoform condensin I also binds to unwound DNA regions at the transcription start sites of active genes, implying that our findings uncover a fundamental feature of condensin complexes. Chromosome condensation is a prerequisite for faithful segregation of chromosomes to daughter cells. Here, the authors show that the condensin complex binds to protein-coding genes in a transcription-dependent manner during condensation, and reduces unwound DNA segments generated by transcription.
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