1
|
Rybchuk J, Xiao W. Dual activities of a silencing information regulator complex in yeast transcriptional regulation and DNA-damage response. MLIFE 2024; 3:207-218. [PMID: 38948145 PMCID: PMC11211678 DOI: 10.1002/mlf2.12108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/11/2024] [Accepted: 01/28/2024] [Indexed: 07/02/2024]
Abstract
The Saccharomyces cerevisiae silencing information regulator (SIR) complex contains up to four proteins, namely Sir1, Sir2, Sir3, and Sir4. While Sir2 encodes a NAD-dependent histone deacetylase, other SIR proteins mainly function as structural and scaffold components through physical interaction with various proteins. The SIR complex displays different conformation and composition, including Sir2 homotrimer, Sir1-4 heterotetramer, Sir2-4 heterotrimer, and their derivatives, which recycle and relocate to different chromosomal regions. Major activities of the SIR complex are transcriptional silencing through chromosomal remodeling and modulation of DNA double-strand-break repair pathways. These activities allow the SIR complex to be involved in mating-type maintenance and switching, telomere and subtelomere gene silencing, promotion of nonhomologous end joining, and inhibition of homologous recombination, as well as control of cell aging. This review explores the potential link between epigenetic regulation and DNA damage response conferred by the SIR complex under various conditions aiming at understanding its roles in balancing cell survival and genomic stability in response to internal and environmental stresses. As core activities of the SIR complex are highly conserved in eukaryotes from yeast to humans, knowledge obtained in the yeast may apply to mammalian Sirtuin homologs and related diseases.
Collapse
Affiliation(s)
- Josephine Rybchuk
- Department of Biochemistry, Microbiology and ImmunologyUniversity of SaskatchewanSaskatoonSaskatchewanCanada
- Toxicology ProgramUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Wei Xiao
- Department of Biochemistry, Microbiology and ImmunologyUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| |
Collapse
|
2
|
Laporte D, Massoni-Laporte A, Lefranc C, Dompierre J, Mauboules D, Nsamba ET, Royou A, Gal L, Schuldiner M, Gupta ML, Sagot I. A stable microtubule bundle formed through an orchestrated multistep process controls quiescence exit. eLife 2024; 12:RP89958. [PMID: 38527106 PMCID: PMC10963028 DOI: 10.7554/elife.89958] [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] [Indexed: 03/27/2024] Open
Abstract
Cells fine-tune microtubule assembly in both space and time to give rise to distinct edifices with specific cellular functions. In proliferating cells, microtubules are highly dynamics, and proliferation cessation often leads to their stabilization. One of the most stable microtubule structures identified to date is the nuclear bundle assembled in quiescent yeast. In this article, we characterize the original multistep process driving the assembly of this structure. This Aurora B-dependent mechanism follows a precise temporality that relies on the sequential actions of kinesin-14, kinesin-5, and involves both microtubule-kinetochore and kinetochore-kinetochore interactions. Upon quiescence exit, the microtubule bundle is disassembled via a cooperative process involving kinesin-8 and its full disassembly is required prior to cells re-entry into proliferation. Overall, our study provides the first description, at the molecular scale, of the entire life cycle of a stable microtubule structure in vivo and sheds light on its physiological function.
Collapse
Affiliation(s)
| | | | | | | | | | - Emmanuel T Nsamba
- Genetics, Development, and Cell Biology, Iowa State UniversityAmesUnited States
| | - Anne Royou
- Univ. Bordeaux, CNRS, IBGC, UMR 5095BordeauxFrance
| | - Lihi Gal
- Department of Molecular Genetics, Weizmann Institute of ScienceRehovotIsrael
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of ScienceRehovotIsrael
| | - Mohan L Gupta
- Genetics, Development, and Cell Biology, Iowa State UniversityAmesUnited States
| | | |
Collapse
|
3
|
Odell J, Lammerding J. Lamins as structural nuclear elements through evolution. Curr Opin Cell Biol 2023; 85:102267. [PMID: 37871500 PMCID: PMC10841731 DOI: 10.1016/j.ceb.2023.102267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/25/2023]
Abstract
Lamins are nuclear intermediate filament proteins with important, well-established roles in humans and other vertebrates. Lamins interact with DNA and numerous proteins at the nuclear envelope to determine the mechanical properties of the nucleus, coordinate chromatin organization, and modulate gene expression. Many of these functions are conserved in the lamin homologs found in basal metazoan organisms, including Drosophila and Caenorhabditis elegans. Lamin homologs have also been recently identified in non-metazoans, like the amoeba Dictyostelium discoideum, yet how these proteins compare functionally to the metazoan isoforms is only beginning to emerge. A better understanding of these distantly related lamins is not only valuable for a more complete picture of eukaryotic evolution, but may also provide new insights into the function of vertebrate lamins.
Collapse
Affiliation(s)
- Jacob Odell
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Graduate Field of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853, USA
| | - Jan Lammerding
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.
| |
Collapse
|
4
|
Dobbs OG, Wilson RHC, Newling K, Ainscough JFX, Coverley D. Epigenetic instability caused by absence of CIZ1 drives transformation during quiescence cycles. BMC Biol 2023; 21:175. [PMID: 37580709 PMCID: PMC10426085 DOI: 10.1186/s12915-023-01671-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 07/31/2023] [Indexed: 08/16/2023] Open
Abstract
BACKGROUND Cip1-interacting zinc finger protein 1 (CIZ1) forms RNA-dependent protein assemblies that stabilise epigenetic state, notable at the inactive X chromosome in females. CIZ1 has been linked with a range of human cancers and in mice genetic deletion of CIZ1 manifests as hyperproliferative lymphoid lineages in females. This suggests that its role in maintenance of epigenetic stability is linked with disease. RESULTS Here, we show that male and female CIZ1-null primary murine fibroblasts have reduced H4K20me1 and that this compromises nuclear condensation on entry to quiescence. Global transcriptional repression remains intact in condensation-deficient CIZ1-null cells; however, a subset of genes linked with chromatin condensation and homology-directed DNA repair are perturbed. Failure to condense is phenotypically mimicked by manipulation of the H4K20me1 methyltransferase, SET8, in WT cells and partially reverted in CIZ1-null cells upon re-expression of CIZ1. Crucially, during exit from quiescence, nuclear decondensation remains active, so that repeated entry and exit cycles give rise to expanded nuclei susceptible to mechanical stress, DNA damage checkpoint activation, and downstream emergence of transformed proliferative colonies. CONCLUSIONS Our results demonstrate a role for CIZ1 in chromatin condensation on entry to quiescence and explore the consequences of this defect in CIZ1-null cells. Together, the data show that CIZ1's protection of the epigenome guards against genome instability during quiescence cycles. This identifies loss of CIZ1 as a potentially devastating vulnerability in cells that undergo cycles of quiescence entry and exit.
Collapse
Affiliation(s)
- Olivia G Dobbs
- Department of Biology, University of York, York, YO10 5DD, UK.
- York Biomedical Research Institute, University of York, York, UK.
| | - Rosemary H C Wilson
- Department of Biology, University of York, York, YO10 5DD, UK
- Exact Sciences Innovation, The Sherard Building, Oxford Science Park, Edmund Halley Rd, Oxford, OX4 4DQ, UK
| | - Katherine Newling
- Department of Biology, University of York, York, YO10 5DD, UK
- Genomics and Bioinformatics Laboratory, Bioscience Technology Facility, University of York, York, YO10 5DD, UK
| | | | - Dawn Coverley
- Department of Biology, University of York, York, YO10 5DD, UK
- York Biomedical Research Institute, University of York, York, UK
| |
Collapse
|
5
|
Opalek M, Tutaj H, Pirog A, Smug BJ, Rutkowska J, Wloch-Salamon D. A Systematic Review on Quiescent State Research Approaches in S. cerevisiae. Cells 2023; 12:1608. [PMID: 37371078 DOI: 10.3390/cells12121608] [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: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Quiescence, the temporary and reversible arrest of cell growth, is a fundamental biological process. However, the lack of standardization in terms of reporting the experimental details of quiescent cells and populations can cause confusion and hinder knowledge transfer. We employ the systematic review methodology to comprehensively analyze the diversity of approaches used to study the quiescent state, focusing on all published research addressing the budding yeast Saccharomyces cerevisiae. We group research articles into those that consider all cells comprising the stationary-phase (SP) population as quiescent and those that recognize heterogeneity within the SP by distinguishing phenotypically distinct subpopulations. Furthermore, we investigate the chronological age of the quiescent populations under study and the methods used to induce the quiescent state, such as gradual starvation or abrupt environmental change. We also assess whether the strains used in research are prototrophic or auxotrophic. By combining the above features, we identify 48 possible experimental setups that can be used to study quiescence, which can be misleading when drawing general conclusions. We therefore summarize our review by proposing guidelines and recommendations pertaining to the information included in research articles. We believe that more rigorous reporting on the features of quiescent populations will facilitate knowledge transfer within and between disciplines, thereby stimulating valuable scientific discussion.
Collapse
Affiliation(s)
- Monika Opalek
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, 30-387 Krakow, Poland
| | - Hanna Tutaj
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, 30-387 Krakow, Poland
| | - Adrian Pirog
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, 30-387 Krakow, Poland
| | - Bogna J Smug
- Malopolska Centre of Biotechnology, Jagiellonian University, 30-387 Krakow, Poland
| | - Joanna Rutkowska
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, 30-387 Krakow, Poland
| | - Dominika Wloch-Salamon
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, 30-387 Krakow, Poland
| |
Collapse
|
6
|
Leonov A, Feldman R, Piano A, Arlia-Ciommo A, Junio JAB, Orfanos E, Tafakori T, Lutchman V, Mohammad K, Elsaser S, Orfali S, Rajen H, Titorenko VI. Diverse geroprotectors differently affect a mechanism linking cellular aging to cellular quiescence in budding yeast. Oncotarget 2022; 13:918-943. [PMID: 35937500 PMCID: PMC9348708 DOI: 10.18632/oncotarget.28256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 07/01/2022] [Indexed: 11/25/2022] Open
Affiliation(s)
- Anna Leonov
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Rachel Feldman
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Amanda Piano
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | | | | | - Emmanuel Orfanos
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Tala Tafakori
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Vicky Lutchman
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Karamat Mohammad
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Sarah Elsaser
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Sandra Orfali
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Harshvardhan Rajen
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | | |
Collapse
|
7
|
Dobbs OG, Coverley D. Chromatin Dynamics During Entry to Quiescence and Compromised Functionality in Cancer Cells. Results Probl Cell Differ 2022; 70:279-294. [PMID: 36348111 DOI: 10.1007/978-3-031-06573-6_9] [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: 06/16/2023]
Abstract
Quiescence is a vital cellular state where cells can reversibly exit the cell cycle and cease proliferation in unfavourable conditions. Cells can undergo multiple transitions in and out of quiescence during their lifetime, and an imbalance in this highly regulated process can promote tumorigenesis and disease. The nucleus experiences vast changes during entry to quiescence, including changes in gene expression and a reduction in size due to increased chromatin compaction. Studies into these changes have highlighted the importance of a core quiescence gene expression programme, reorganisation of nuclear structures, and the action of the condensin complex in creating a stable, quiescent nucleus. However, the underpinning mechanisms behind the formation of a quiescent nucleus are still not fully understood. This chapter explores the current literature surrounding chromatin dynamics during entry to quiescence and the association between quiescence and disease and accentuates the need for further studies to understand this transition. Linking failure to maintain a stable, quiescent state with potential genome instability may help in the advancement of medical interventions for a range of diseases, including cancer.
Collapse
|
8
|
Bonitto K, Sarathy K, Atai K, Mitra M, Coller HA. Is There a Histone Code for Cellular Quiescence? Front Cell Dev Biol 2021; 9:739780. [PMID: 34778253 PMCID: PMC8586460 DOI: 10.3389/fcell.2021.739780] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 09/17/2021] [Indexed: 12/14/2022] Open
Abstract
Many of the cells in our bodies are quiescent, that is, temporarily not dividing. Under certain physiological conditions such as during tissue repair and maintenance, quiescent cells receive the appropriate stimulus and are induced to enter the cell cycle. The ability of cells to successfully transition into and out of a quiescent state is crucial for many biological processes including wound healing, stem cell maintenance, and immunological responses. Across species and tissues, transcriptional, epigenetic, and chromosomal changes associated with the transition between proliferation and quiescence have been analyzed, and some consistent changes associated with quiescence have been identified. Histone modifications have been shown to play a role in chromatin packing and accessibility, nucleosome mobility, gene expression, and chromosome arrangement. In this review, we critically evaluate the role of different histone marks in these processes during quiescence entry and exit. We consider different model systems for quiescence, each of the most frequently monitored candidate histone marks, and the role of their writers, erasers and readers. We highlight data that support these marks contributing to the changes observed with quiescence. We specifically ask whether there is a quiescence histone “code,” a mechanism whereby the language encoded by specific combinations of histone marks is read and relayed downstream to modulate cell state and function. We conclude by highlighting emerging technologies that can be applied to gain greater insight into the role of a histone code for quiescence.
Collapse
Affiliation(s)
- Kenya Bonitto
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Kirthana Sarathy
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Kaiser Atai
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States.,Molecular Biology Interdepartmental Doctoral Program, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Mithun Mitra
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Hilary A Coller
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
9
|
Swygert SG, Lin D, Portillo-Ledesma S, Lin PY, Hunt DR, Kao CF, Schlick T, Noble WS, Tsukiyama T. Local chromatin fiber folding represses transcription and loop extrusion in quiescent cells. eLife 2021; 10:e72062. [PMID: 34734806 PMCID: PMC8598167 DOI: 10.7554/elife.72062] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/03/2021] [Indexed: 12/16/2022] Open
Abstract
A longstanding hypothesis is that chromatin fiber folding mediated by interactions between nearby nucleosomes represses transcription. However, it has been difficult to determine the relationship between local chromatin fiber compaction and transcription in cells. Further, global changes in fiber diameters have not been observed, even between interphase and mitotic chromosomes. We show that an increase in the range of local inter-nucleosomal contacts in quiescent yeast drives the compaction of chromatin fibers genome-wide. Unlike actively dividing cells, inter-nucleosomal interactions in quiescent cells require a basic patch in the histone H4 tail. This quiescence-specific fiber folding globally represses transcription and inhibits chromatin loop extrusion by condensin. These results reveal that global changes in chromatin fiber compaction can occur during cell state transitions, and establish physiological roles for local chromatin fiber folding in regulating transcription and chromatin domain formation.
Collapse
Affiliation(s)
- Sarah G Swygert
- Basic Sciences Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Dejun Lin
- Department of Genome Sciences, University of WashingtonSeattleUnited States
| | | | - Po-Yen Lin
- Institute of Cellular and Organismic Biology, Academia SinicaTaipeiTaiwan
| | - Dakota R Hunt
- Basic Sciences Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Cheng-Fu Kao
- Institute of Cellular and Organismic Biology, Academia SinicaTaipeiTaiwan
| | - Tamar Schlick
- Department of Chemistry, New York UniversityNew YorkUnited States
- Courant Institute of Mathematical Sciences, New York UniversityNew YorkUnited States
- New York University-East China Normal University Center for Computational Chemistry at New York University ShanghaiShanghaiChina
| | - William S Noble
- Department of Genome Sciences, University of WashingtonSeattleUnited States
- Paul G. Allen School of Computer Science and Engineering, University of WashingtonSeattleUnited States
| | - Toshio Tsukiyama
- Basic Sciences Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| |
Collapse
|
10
|
Doughty TW, Yu R, Chao LFI, Qin Z, Siewers V, Nielsen J. A single chromosome strain of S. cerevisiae exhibits diminished ethanol metabolism and tolerance. BMC Genomics 2021; 22:688. [PMID: 34551706 PMCID: PMC8456624 DOI: 10.1186/s12864-021-07947-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 08/25/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Eukaryotic organisms, like the model yeast S. cerevisiae, have linear chromosomes that facilitate organization and protection of nuclear DNA. A recent work described a stepwise break/repair method that enabled fusion of the 16 chromosomes of S. cerevisiae into a single large chromosome. Construction of this strain resulted in the removal of 30 of 32 telomeres, over 300 kb of subtelomeric DNA, and 107 subtelomeric ORFs. Despite these changes, characterization of the single chromosome strain uncovered modest phenotypes compared to a reference strain. RESULTS This study further characterized the single chromosome strain and found that it exhibited a longer lag phase, increased doubling time, and lower final biomass concentration compared with a reference strain when grown on YPD. These phenotypes were amplified when ethanol was added to the medium or used as the sole carbon source. RNAseq analysis showed poor induction of genes involved in diauxic shift, ethanol metabolism, and fatty-acid ß-oxidation during growth on ethanol compared to the reference strain. Enzyme-constrained metabolic modeling identified decreased flux through the enzymes that are encoded by these poorly induced genes as a likely cause of diminished biomass accumulation. The diminished growth on ethanol for the single chromosome strain was rescued by nicotinamide, an inhibitor of sirtuin family deacetylases, which have been shown to silence gene expression in heterochromatic regions. CONCLUSIONS Our results indicate that sirtuin-mediated silencing in the single chromosome strain interferes with growth on non-fermentable carbon sources. We propose that the removal of subtelomeric DNA that would otherwise be bound by sirtuins leads to silencing at other loci in the single chromosome strain. Further, we hypothesize that the poorly induced genes in the single chromosome strain during ethanol growth could be silenced by sirtuins in wildtype S. cerevisiae during growth on glucose.
Collapse
Affiliation(s)
- Tyler W Doughty
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Rosemary Yu
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Lucy Fang-I Chao
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Zhongjun Qin
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Verena Siewers
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
- BioInnovation Institute, DK-2200, Copenhagen N, Denmark.
| |
Collapse
|
11
|
Subtelomeric Chromatin in the Fission Yeast S. pombe. Microorganisms 2021; 9:microorganisms9091977. [PMID: 34576871 PMCID: PMC8466458 DOI: 10.3390/microorganisms9091977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/06/2021] [Accepted: 09/14/2021] [Indexed: 01/15/2023] Open
Abstract
Telomeres play important roles in safeguarding the genome. The specialized repressive chromatin that assembles at telomeres and subtelomeric domains is key to this protective role. However, in many organisms, the repetitive nature of telomeric and subtelomeric sequences has hindered research efforts. The fission yeast S. pombe has provided an important model system for dissection of chromatin biology due to the relative ease of genetic manipulation and strong conservation of important regulatory proteins with higher eukaryotes. Telomeres and the telomere-binding shelterin complex are highly conserved with mammals, as is the assembly of constitutive heterochromatin at subtelomeres. In this review, we seek to summarize recent work detailing the assembly of distinct chromatin structures within subtelomeric domains in fission yeast. These include the heterochromatic SH subtelomeric domains, the telomere-associated sequences (TAS), and ST chromatin domains that assemble highly condensed chromatin clusters called knobs. Specifically, we review new insights into the sequence of subtelomeric domains, the distinct types of chromatin that assemble on these sequences and how histone H3 K36 modifications influence these chromatin structures. We address the interplay between the subdomains of chromatin structure and how subtelomeric chromatin is influenced by both the telomere-bound shelterin complexes and by euchromatic chromatin regulators internal to the subtelomeric domain. Finally, we demonstrate that telomere clustering, which is mediated via the condensed ST chromatin knob domains, does not depend on knob assembly within these domains but on Set2, which mediates H3K36 methylation.
Collapse
|
12
|
Abstract
Membrane-bound organelles provide physical and functional compartmentalization of biological processes in eukaryotic cells. The characteristic shape and internal organization of these organelles is determined by a combination of multiple internal and external factors. The maintenance of the shape of nucleus, which houses the genetic material within a double membrane bilayer, is crucial for a seamless spatio-temporal control over nuclear and cellular functions. Dynamic morphological changes in the shape of nucleus facilitate various biological processes. Chromatin packaging, nuclear and cytosolic protein organization, and nuclear membrane lipid homeostasis are critical determinants of overall nuclear morphology. As such, a multitude of molecular players and pathways act together to regulate the nuclear shape. Here, we review the known mechanisms governing nuclear shape in various unicellular and multicellular organisms, including the non-spherical nuclei and non-lamin-related structural determinants. The review also touches upon cellular consequences of aberrant nuclear morphologies.
Collapse
Affiliation(s)
- Pallavi Deolal
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Krishnaveni Mishra
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| |
Collapse
|
13
|
Enriquez-Hesles E, Smith DL, Maqani N, Wierman MB, Sutcliffe MD, Fine RD, Kalita A, Santos SM, Muehlbauer MJ, Bain JR, Janes KA, Hartman JL, Hirschey MD, Smith JS. A cell-nonautonomous mechanism of yeast chronological aging regulated by caloric restriction and one-carbon metabolism. J Biol Chem 2021; 296:100125. [PMID: 33243834 PMCID: PMC7949035 DOI: 10.1074/jbc.ra120.015402] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/26/2020] [Accepted: 11/25/2020] [Indexed: 12/30/2022] Open
Abstract
Caloric restriction (CR) improves health span and life span of organisms ranging from yeast to mammals. Understanding the mechanisms involved will uncover future interventions for aging-associated diseases. In budding yeast, Saccharomyces cerevisiae, CR is commonly defined by reduced glucose in the growth medium, which extends both replicative and chronological life span (CLS). We found that conditioned media collected from stationary-phase CR cultures extended CLS when supplemented into nonrestricted (NR) cultures, suggesting a potential cell-nonautonomous mechanism of CR-induced life span regulation. Chromatography and untargeted metabolomics of the conditioned media, as well as transcriptional responses associated with the longevity effect, pointed to specific amino acids enriched in the CR conditioned media (CRCM) as functional molecules, with L-serine being a particularly strong candidate. Indeed, supplementing L-serine into NR cultures extended CLS through a mechanism dependent on the one-carbon metabolism pathway, thus implicating this conserved and central metabolic hub in life span regulation.
Collapse
Affiliation(s)
- Elisa Enriquez-Hesles
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Daniel L Smith
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Nutrition Science, Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Nazif Maqani
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Margaret B Wierman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Matthew D Sutcliffe
- Department of Biomedical Engineering, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Ryan D Fine
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Agata Kalita
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Sean M Santos
- Department of Genetics, Nutrition and Obesity Research Center, Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Michael J Muehlbauer
- Department of Medicine, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - James R Bain
- Department of Medicine, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Kevin A Janes
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Biomedical Engineering, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - John L Hartman
- Department of Genetics, Nutrition and Obesity Research Center, Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Matthew D Hirschey
- Department of Medicine, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Jeffrey S Smith
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA.
| |
Collapse
|
14
|
Miles S, Bradley GT, Breeden LL. The budding yeast transition to quiescence. Yeast 2021; 38:30-38. [PMID: 33350501 DOI: 10.1002/yea.3546] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 11/06/2022] Open
Abstract
A subset of Saccharomyces cerevisiae cells in a stationary phase culture achieve a unique quiescent state characterized by increased cell density, stress tolerance, and longevity. Trehalose accumulation is necessary but not sufficient for conferring this state, and it is not recapitulated by abrupt starvation. The fraction of cells that achieve this state varies widely in haploids and diploids and can approach 100%, indicating that both mother and daughter cells can enter quiescence. The transition begins when about half the glucose has been taken up from the medium. The high affinity glucose transporters are turned on, glycogen storage begins, the Rim15 kinase enters the nucleus and the accumulation of cells in G1 is initiated. After the diauxic shift (DS), when glucose is exhausted from the medium, growth promoting genes are repressed by the recruitment of the histone deacetylase Rpd3 by quiescence-specific repressors. The final division that takes place post-DS is highly asymmetrical and G1 arrest is complete after 48 h. The timing of these events can vary considerably, but they are tightly correlated with total biomass of the culture, suggesting that the transition to quiescence is tightly linked to changes in external glucose levels. After 7 days in culture, there are massive morphological changes at the protein and organelle level. There are global changes in histone modification. An extensive array of condensin-dependent, long-range chromatin interactions lead to genome-wide chromatin compaction that is conserved in yeast and human cells. These interactions are required for the global transcriptional repression that occurs in quiescent yeast.
Collapse
Affiliation(s)
- Shawna Miles
- Fred Hutchinson Cancer Research Center, Basic Science Division, Seattle, Washington, USA
| | | | - Linda L Breeden
- Fred Hutchinson Cancer Research Center, Basic Science Division, Seattle, Washington, USA
| |
Collapse
|
15
|
An Epigenetic Priming Mechanism Mediated by Nutrient Sensing Regulates Transcriptional Output during C. elegans Development. Curr Biol 2020; 31:809-826.e6. [PMID: 33357451 DOI: 10.1016/j.cub.2020.11.060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/07/2020] [Accepted: 11/23/2020] [Indexed: 11/23/2022]
Abstract
Although precise tuning of gene expression levels is critical for most developmental pathways, the mechanisms by which the transcriptional output of dosage-sensitive molecules is established or modulated by the environment remain poorly understood. Here, we provide a mechanistic framework for how the conserved transcription factor BLMP-1/Blimp1 operates as a pioneer factor to decompact chromatin near its target loci during embryogenesis (hours prior to major transcriptional activation) and, by doing so, regulates both the duration and amplitude of subsequent target gene transcription during post-embryonic development. This priming mechanism is genetically separable from the mechanisms that establish the timing of transcriptional induction and functions to canalize aspects of cell-fate specification, animal size regulation, and molting. A key feature of the BLMP-1-dependent transcriptional priming mechanism is that chromatin decompaction is initially established during embryogenesis and maintained throughout larval development by nutrient sensing. This anticipatory mechanism integrates transcriptional output with environmental conditions and is essential for resuming normal temporal patterning after animals exit nutrient-mediated developmental arrests.
Collapse
|
16
|
Mohammad K, Baratang Junio JA, Tafakori T, Orfanos E, Titorenko VI. Mechanisms that Link Chronological Aging to Cellular Quiescence in Budding Yeast. Int J Mol Sci 2020; 21:ijms21134717. [PMID: 32630624 PMCID: PMC7369985 DOI: 10.3390/ijms21134717] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 06/27/2020] [Accepted: 06/30/2020] [Indexed: 12/28/2022] Open
Abstract
After Saccharomyces cerevisiae cells cultured in a medium with glucose consume glucose, the sub-populations of quiescent and non-quiescent cells develop in the budding yeast culture. An age-related chronology of quiescent and non-quiescent yeast cells within this culture is discussed here. We also describe various hallmarks of quiescent and non-quiescent yeast cells. A complex aging-associated program underlies cellular quiescence in budding yeast. This quiescence program includes a cascade of consecutive cellular events orchestrated by an intricate signaling network. We examine here how caloric restriction, a low-calorie diet that extends lifespan and healthspan in yeast and other eukaryotes, influences the cellular quiescence program in S. cerevisiae. One of the main objectives of this review is to stimulate an exploration of the mechanisms that link cellular quiescence to chronological aging of budding yeast. Yeast chronological aging is defined by the length of time during which a yeast cell remains viable after its growth and division are arrested, and it becomes quiescent. We propose a hypothesis on how caloric restriction can slow chronological aging of S. cerevisiae by altering the chronology and properties of quiescent cells. Our hypothesis posits that caloric restriction delays yeast chronological aging by targeting four different processes within quiescent cells.
Collapse
|
17
|
Okuda EK, Gonzales-Zubiate FA, Gadal O, Oliveira CC. Nucleolar localization of the yeast RNA exosome subunit Rrp44 hints at early pre-rRNA processing as its main function. J Biol Chem 2020; 295:11195-11213. [PMID: 32554806 DOI: 10.1074/jbc.ra120.013589] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/12/2020] [Indexed: 01/12/2023] Open
Abstract
The RNA exosome is a multisubunit protein complex involved in RNA surveillance of all classes of RNA, and is essential for pre-rRNA processing. The exosome is conserved throughout evolution, present in archaea and eukaryotes from yeast to humans, where it localizes to the nucleus and cytoplasm. The catalytically active subunit Rrp44/Dis3 of the exosome in budding yeast (Saccharomyces cerevisiae) is considered a protein present in these two subcellular compartments, and here we report that it not only localizes mainly to the nucleus, but is concentrated in the nucleolus, where the early pre-rRNA processing reactions take place. Moreover, we show by confocal microscopy analysis that the core exosome subunits Rrp41 and Rrp43 also localize largely to the nucleus and strongly accumulate in the nucleolus. These results shown here shed additional light on the localization of the yeast exosome and have implications regarding the main function of this RNase complex, which seems to be primarily in early pre-rRNA processing and surveillance.
Collapse
Affiliation(s)
- Ellen K Okuda
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | | | - Olivier Gadal
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Carla C Oliveira
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| |
Collapse
|
18
|
Maestroni L, Reyes C, Vaurs M, Gachet Y, Tournier S, Géli V, Coulon S. Nuclear envelope attachment of telomeres limits TERRA and telomeric rearrangements in quiescent fission yeast cells. Nucleic Acids Res 2020; 48:3029-3041. [PMID: 31980821 PMCID: PMC7102995 DOI: 10.1093/nar/gkaa043] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 11/12/2022] Open
Abstract
Telomere anchoring to nuclear envelope (NE) is a key feature of nuclear genome architecture. Peripheral localization of telomeres is important for chromatin silencing, telomere replication and for the control of inappropriate recombination. Here, we report that fission yeast quiescent cells harbor predominantly a single telomeric cluster anchored to the NE. Telomere cluster association to the NE relies on Rap1-Bqt4 interaction, which is impacted by the length of telomeric sequences. In quiescent cells, reducing telomere length or deleting bqt4, both result in an increase in transcription of the telomeric repeat-containing RNA (TERRA). In the absence of Bqt4, telomere shortening leads to deep increase in TERRA level and the concomitant formation of subtelomeric rearrangements (STEEx) that accumulate massively in quiescent cells. Taken together, our data demonstrate that Rap1-Bqt4-dependent telomere association to NE preserves telomere integrity in post-mitotic cells, preventing telomeric transcription and recombination. This defines the nuclear periphery as an area where recombination is restricted, creating a safe zone for telomeres of post-mitotic cells.
Collapse
Affiliation(s)
- Laetitia Maestroni
- CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes, CRCM, Marseille, France. Equipe labellisée Ligue contre le Cancer, France
| | - Céline Reyes
- LBCMCP, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Mélina Vaurs
- CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes, CRCM, Marseille, France. Equipe labellisée Ligue contre le Cancer, France
| | - Yannick Gachet
- LBCMCP, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Sylvie Tournier
- LBCMCP, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Vincent Géli
- CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes, CRCM, Marseille, France. Equipe labellisée Ligue contre le Cancer, France
| | - Stéphane Coulon
- CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes, CRCM, Marseille, France. Equipe labellisée Ligue contre le Cancer, France
| |
Collapse
|
19
|
Panchy NL, Lloyd JP, Shiu SH. Improved recovery of cell-cycle gene expression in Saccharomyces cerevisiae from regulatory interactions in multiple omics data. BMC Genomics 2020; 21:159. [PMID: 32054475 PMCID: PMC7020519 DOI: 10.1186/s12864-020-6554-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 02/04/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Gene expression is regulated by DNA-binding transcription factors (TFs). Together with their target genes, these factors and their interactions collectively form a gene regulatory network (GRN), which is responsible for producing patterns of transcription, including cyclical processes such as genome replication and cell division. However, identifying how this network regulates the timing of these patterns, including important interactions and regulatory motifs, remains a challenging task. RESULTS We employed four in vivo and in vitro regulatory data sets to investigate the regulatory basis of expression timing and phase-specific patterns cell-cycle expression in Saccharomyces cerevisiae. Specifically, we considered interactions based on direct binding between TF and target gene, indirect effects of TF deletion on gene expression, and computational inference. We found that the source of regulatory information significantly impacts the accuracy and completeness of recovering known cell-cycle expressed genes. The best approach involved combining TF-target and TF-TF interactions features from multiple datasets in a single model. In addition, TFs important to multiple phases of cell-cycle expression also have the greatest impact on individual phases. Important TFs regulating a cell-cycle phase also tend to form modules in the GRN, including two sub-modules composed entirely of unannotated cell-cycle regulators (STE12-TEC1 and RAP1-HAP1-MSN4). CONCLUSION Our findings illustrate the importance of integrating both multiple omics data and regulatory motifs in order to understand the significance regulatory interactions involved in timing gene expression. This integrated approached allowed us to recover both known cell-cycles interactions and the overall pattern of phase-specific expression across the cell-cycle better than any single data set. Likewise, by looking at regulatory motifs in the form of TF-TF interactions, we identified sets of TFs whose co-regulation of target genes was important for cell-cycle expression, even when regulation by individual TFs was not. Overall, this demonstrates the power of integrating multiple data sets and models of interaction in order to understand the regulatory basis of established biological processes and their associated gene regulatory networks.
Collapse
Affiliation(s)
- Nicholas L Panchy
- Genetics Graduate Program, Michigan State University, East Lansing, MI, 48824, USA.,Present address: National Institute for Mathematical and Biological Synthesis, University of Tennessee, 1122 Volunteer Blvd., Suite 106, Knoxville, TN, 37996-3410, USA
| | - John P Lloyd
- Department of Human Genetics and Internal Medicine, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Shin-Han Shiu
- Genetics Graduate Program, Michigan State University, East Lansing, MI, 48824, USA. .,Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA. .,Michigan State University, Plant Biology Laboratories, 612 Wilson Road, Room 166, East Lansing, MI, 48824-1312, USA.
| |
Collapse
|
20
|
Zhang J, Martinez-Gomez K, Heinzle E, Wahl SA. Metabolic switches from quiescence to growth in synchronized Saccharomyces cerevisiae. Metabolomics 2019; 15:121. [PMID: 31468142 PMCID: PMC6715666 DOI: 10.1007/s11306-019-1584-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 08/09/2019] [Indexed: 12/27/2022]
Abstract
INTRODUCTION The switch from quiescence (G0) into G1 and cell cycle progression critically depends on specific nutrients and metabolic capabilities. Conversely, metabolic networks are regulated by enzyme-metabolite interaction and transcriptional regulation that lead to flux modifications to support cell growth. How cells process and integrate environmental information into coordinated responses is challenging to analyse and not yet described quantitatively. OBJECTIVES To quantitatively monitor the central carbon metabolism during G0 exit and the first 2 h after reentering the cell cycle from synchronized Saccharomyces cerevisiae. METHODS Dynamic tailored 13C metabolic flux analysis was used to observe the intracellular metabolite flux changes, and the metabolome and proteome were observed to identify regulatory mechanisms. RESULTS G0 cells responded immediately to an extracellular increase of glucose. The intracellular metabolic flux changed in time and specific events were observed. High fluxes into trehalose and glycogen synthesis were observed during the G0 exit. Both fluxes then decreased, reaching a minimum at t = 65 min. Here, storage degradation contributed significantly (i.e. 21%) to the glycolytic flux. In contrast to these changes, the glucose uptake rate remained constant after the G0 exit. The flux into the oxidative pentose phosphate pathway was highest (29-fold increase, 36.4% of the glucose uptake) at t = 65 min, while it was very low at other time points. The maximum flux seems to correlate with a late G1 state preparing for the S phase transition. In the G1/S phase (t = 87 min), anaplerotic reactions such as glyoxylate shunt increased. Protein results show that during this transition, proteins belonging to clusters related with ribosome biogenesis and assembly, and initiation transcription factors clusters were continuously synthetised. CONCLUSION The intracellular flux distribution changes dynamically and these major rearrangements highlight the coordinate reorganization of metabolic flux to meet requirements for growth during different cell state.
Collapse
Affiliation(s)
- Jinrui Zhang
- 0000 0001 2097 4740grid.5292.cDepartment of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Karla Martinez-Gomez
- 0000 0001 2167 7588grid.11749.3aBiochemical Engineering, Saarland University, Campus A 1.5, 66123 Saarbrücken, Germany
| | - Elmar Heinzle
- 0000 0001 2167 7588grid.11749.3aBiochemical Engineering, Saarland University, Campus A 1.5, 66123 Saarbrücken, Germany
| | - Sebastian Aljoscha Wahl
- 0000 0001 2097 4740grid.5292.cDepartment of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| |
Collapse
|
21
|
Unraveling quiescence-specific repressive chromatin domains. Curr Genet 2019; 65:1145-1151. [PMID: 31055637 DOI: 10.1007/s00294-019-00985-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 01/30/2023]
Abstract
Quiescence is a highly conserved inactive life stage in which the cell reversibly exits the cell cycle in response to external cues. Quiescence is essential for diverse processes such as the maintenance of adult stem cell stores, stress resistance, and longevity, and its misregulation has been implicated in cancer. Although the non-cycling nature of quiescent cells has made obtaining sufficient quantities of quiescent cells for study difficult, the development of a Saccharomyces cerevisiae model of quiescence has recently enabled detailed investigation into mechanisms underlying the quiescent state. Like their metazoan counterparts, quiescent budding yeast exhibit widespread transcriptional silencing and dramatic chromatin condensation. We have recently found that the structural maintenance of chromosomes (SMC) complex condensin binds throughout the quiescent budding yeast genome and induces the formation of large chromatin loop domains. In the absence of condensin, quiescent cell chromatin is decondensed and transcription is de-repressed. Here, we briefly discuss our findings in the larger context of the genome organization field.
Collapse
|
22
|
Miné-Hattab J, Taddei A. Physical principles and functional consequences of nuclear compartmentalization in budding yeast. Curr Opin Cell Biol 2019; 58:105-113. [PMID: 30928833 DOI: 10.1016/j.ceb.2019.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/28/2019] [Accepted: 02/20/2019] [Indexed: 12/19/2022]
Abstract
One striking feature of eukaryotic nuclei is the existence of discrete regions, in which specific factors concentrate while others are excluded, thus forming microenvironments with different molecular compositions and biological functions. These domains are often referred to as subcompartments even though they are not membrane enclosed. Despite their functional importance the physical nature of these structures remains largely unknown. Here, we describe how the Saccharomyces cerevisiae nucleus is compartmentalized and discuss possible physical models underlying the formation and maintenance of chromatin associated subcompartments. Focusing on three particular examples, the nucleolus, silencing foci, and repair foci, we discuss the biological implications of these different models as well as possible approaches to challenge them in living cells.
Collapse
Affiliation(s)
- Judith Miné-Hattab
- Institut Curi-PSL Research University, CNRS, Sorbonne Université, UMR3664, F-75005, Paris, France
| | - Angela Taddei
- Institut Curi-PSL Research University, CNRS, Sorbonne Université, UMR3664, F-75005, Paris, France.
| |
Collapse
|
23
|
Swygert SG, Kim S, Wu X, Fu T, Hsieh TH, Rando OJ, Eisenman RN, Shendure J, McKnight JN, Tsukiyama T. Condensin-Dependent Chromatin Compaction Represses Transcription Globally during Quiescence. Mol Cell 2019; 73:533-546.e4. [PMID: 30595435 PMCID: PMC6368455 DOI: 10.1016/j.molcel.2018.11.020] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 09/25/2018] [Accepted: 11/15/2018] [Indexed: 02/03/2023]
Abstract
Quiescence is a stress-resistant state in which cells reversibly exit the cell cycle and suspend most processes. Quiescence is essential for stem cell maintenance, and its misregulation is implicated in tumor formation. One of the hallmarks of quiescent cells is highly condensed chromatin. Because condensed chromatin often correlates with transcriptional silencing, it has been hypothesized that chromatin compaction represses transcription during quiescence. However, the technology to test this model by determining chromatin structure within cells at gene resolution has not previously been available. Here, we use Micro-C XL to map chromatin contacts at single-nucleosome resolution genome-wide in quiescent Saccharomyces cerevisiae cells. We describe chromatin domains on the order of 10-60 kilobases that, only in quiescent cells, are formed by condensin-mediated loops. Condensin depletion prevents the compaction of chromatin within domains and leads to widespread transcriptional de-repression. Finally, we demonstrate that condensin-dependent chromatin compaction is conserved in quiescent human fibroblasts.
Collapse
Affiliation(s)
- Sarah G Swygert
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Seungsoo Kim
- Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Xiaoying Wu
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Tianhong Fu
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Tsung-Han Hsieh
- Biochemistry and Molecular Pharmacology, University of Massachusetts, Worcester, MA 01605, USA
| | - Oliver J Rando
- Biochemistry and Molecular Pharmacology, University of Massachusetts, Worcester, MA 01605, USA
| | - Robert N Eisenman
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Jay Shendure
- Genome Sciences, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, Seattle, WA 98195, USA
| | - Jeffrey N McKnight
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Toshio Tsukiyama
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
| |
Collapse
|
24
|
Sagot I, Laporte D. The cell biology of quiescent yeast – a diversity of individual scenarios. J Cell Sci 2019; 132:132/1/jcs213025. [DOI: 10.1242/jcs.213025] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
ABSTRACT
Most cells, from unicellular to complex organisms, spend part of their life in quiescence, a temporary non-proliferating state. Although central for a variety of essential processes including tissue homeostasis, development and aging, quiescence is poorly understood. In fact, quiescence encompasses various cellular situations depending on the cell type and the environmental niche. Quiescent cell properties also evolve with time, adding another layer of complexity. Studying quiescence is, above all, limited by the fact that a quiescent cell can be recognized as such only after having proved that it is capable of re-proliferating. Recent cellular biology studies in yeast have reported the relocalization of hundreds of proteins and the reorganization of several cellular machineries upon proliferation cessation. These works have revealed that quiescent cells can display various properties, shedding light on a plethora of individual behaviors. The deciphering of the molecular mechanisms beyond these reorganizations, together with the understanding of their cellular functions, have begun to provide insights into the physiology of quiescent cells. In this Review, we discuss recent findings and emerging concepts in Saccharomyces cerevisiae quiescent cell biology.
Collapse
Affiliation(s)
- Isabelle Sagot
- Centre National de la Recherche Scientifique, Université de Bordeaux-Institut de Biochimie et Génétique Cellulaires, UMR5095-33077 Bordeaux cedex, France
| | - Damien Laporte
- Centre National de la Recherche Scientifique, Université de Bordeaux-Institut de Biochimie et Génétique Cellulaires, UMR5095-33077 Bordeaux cedex, France
| |
Collapse
|
25
|
de Bruyn Kops A, Burke JE, Guthrie C. Brr6 plays a role in gene recruitment and transcriptional regulation at the nuclear envelope. Mol Biol Cell 2018; 29:2578-2590. [PMID: 30133335 PMCID: PMC6254580 DOI: 10.1091/mbc.e18-04-0258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Correlation between transcriptional regulation and positioning of genes at the nuclear envelope is well established in eukaryotes, but the mechanisms involved are not well understood. We show that brr6-1, a mutant of the essential yeast envelope transmembrane protein Brr6p, impairs normal positioning and expression of the PAB1 and FUR4-GAL1,10,7 loci. Similarly, expression of a dominant negative nucleoplasmic Brr6 fragment in wild-type cells reproduced many of the brr6-1 effects. Histone chromatin immunoprecipitation (ChIP) experiments showed decreased acetylation at the key histone H4K16 residue in the FUR4-GAL1,10,7 region in brr6-1. Importantly, blocking deacetylation significantly suppressed selected brr6-1 phenotypes. ChIPseq with FLAG-tagged Brr6 fragments showed enrichment at FUR4 and several other genes that showed striking changes in brr6-1 RNAseq data. These associations depended on a Brr6 putative zinc finger domain. Importantly, artificially tethering the GAL1 locus to the envelope suppressed the brr6-1 effects on GAL1 and FUR4 expression and increased H4K16 acetylation between GAL1 and FUR4 in the mutant. Together these results argue that Brr6 interacts with chromatin, helping to maintain normal chromatin architecture and transcriptional regulation of certain loci at the nuclear envelope.
Collapse
Affiliation(s)
- Anne de Bruyn Kops
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143
| | - Jordan E Burke
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143
| | - Christine Guthrie
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143
| |
Collapse
|
26
|
Laporte D, Gouleme L, Jimenez L, Khemiri I, Sagot I. Mitochondria reorganization upon proliferation arrest predicts individual yeast cell fate. eLife 2018; 7:35685. [PMID: 30299253 PMCID: PMC6177259 DOI: 10.7554/elife.35685] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 09/14/2018] [Indexed: 02/06/2023] Open
Abstract
Most cells spend the majority of their life in a non-proliferating state. When proliferation cessation is irreversible, cells are senescent. By contrast, if the arrest is only temporary, cells are defined as quiescent. These cellular states are hardly distinguishable without triggering proliferation resumption, hampering thus the study of quiescent cells properties. Here we show that quiescent and senescent yeast cells are recognizable based on their mitochondrial network morphology. Indeed, while quiescent yeast cells display numerous small vesicular mitochondria, senescent cells exhibit few globular mitochondria. This allowed us to reconsider at the individual-cell level, properties previously attributed to quiescent cells using population-based approaches. We demonstrate that cell’s propensity to enter quiescence is not influenced by replicative age, volume or density. Overall, our findings reveal that quiescent cells are not all identical but that their ability to survive is significantly improved when they exhibit the specific reorganization of several cellular machineries.
Collapse
Affiliation(s)
- Damien Laporte
- Centre National de la Recherche Scientifique, Université de Bordeaux - Institut de Biochimie et Génétique Cellulaires, Bordeaux, France
| | - Laëtitia Gouleme
- Centre National de la Recherche Scientifique, Université de Bordeaux - Institut de Biochimie et Génétique Cellulaires, Bordeaux, France
| | - Laure Jimenez
- Centre National de la Recherche Scientifique, Université de Bordeaux - Institut de Biochimie et Génétique Cellulaires, Bordeaux, France
| | - Ines Khemiri
- Centre National de la Recherche Scientifique, Université de Bordeaux - Institut de Biochimie et Génétique Cellulaires, Bordeaux, France
| | - Isabelle Sagot
- Centre National de la Recherche Scientifique, Université de Bordeaux - Institut de Biochimie et Génétique Cellulaires, Bordeaux, France
| |
Collapse
|
27
|
Wloch-Salamon DM, Fisher RM, Regenberg B. Division of labour in the yeast:Saccharomyces cerevisiae. Yeast 2017; 34:399-406. [DOI: 10.1002/yea.3241] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/24/2017] [Accepted: 06/27/2017] [Indexed: 12/12/2022] Open
Affiliation(s)
| | - Roberta M. Fisher
- Department of Biology; University of Copenhagen; Universitetsparken 13 DK-2100 Copenhagen Denmark
- Centre for Social Evolution, Department of Biology; University of Copenhagen; Universitetsparken 15 Copenhagen Denmark
| | - Birgitte Regenberg
- Department of Biology; University of Copenhagen; Universitetsparken 13 DK-2100 Copenhagen Denmark
| |
Collapse
|
28
|
Adaptive Roles of SSY1 and SIR3 During Cycles of Growth and Starvation in Saccharomyces cerevisiae Populations Enriched for Quiescent or Nonquiescent Cells. G3-GENES GENOMES GENETICS 2017; 7:1899-1911. [PMID: 28450371 PMCID: PMC5473767 DOI: 10.1534/g3.117.041749] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Over its evolutionary history, Saccharomyces cerevisiae has evolved to be well-adapted to fluctuating nutrient availability. In the presence of sufficient nutrients, yeast cells continue to proliferate, but upon starvation haploid yeast cells enter stationary phase and differentiate into nonquiescent (NQ) and quiescent (Q) cells. Q cells survive stress better than NQ cells and show greater viability when nutrient-rich conditions are restored. To investigate the genes that may be involved in the differentiation of Q and NQ cells, we serially propagated yeast populations that were enriched for either only Q or only NQ cell types over many repeated growth–starvation cycles. After 30 cycles (equivalent to 300 generations), each enriched population produced a higher proportion of the enriched cell type compared to the starting population, suggestive of adaptive change. We also observed differences in each population’s fitness suggesting possible tradeoffs: clones from NQ lines were better adapted to logarithmic growth, while clones from Q lines were better adapted to starvation. Whole-genome sequencing of clones from Q- and NQ-enriched lines revealed mutations in genes involved in the stress response and survival in limiting nutrients (ECM21, RSP5, MSN1, SIR4, and IRA2) in both Q and NQ lines, but also differences between the two lines: NQ line clones had recurrent independent mutations affecting the Ssy1p-Ptr3p-Ssy5p (SPS) amino acid sensing pathway, while Q line clones had recurrent, independent mutations in SIR3 and FAS1. Our results suggest that both sets of enriched-cell type lines responded to common, as well as distinct, selective pressures.
Collapse
|
29
|
Spichal M, Fabre E. The Emerging Role of the Cytoskeleton in Chromosome Dynamics. Front Genet 2017; 8:60. [PMID: 28580009 PMCID: PMC5437106 DOI: 10.3389/fgene.2017.00060] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 04/28/2017] [Indexed: 01/15/2023] Open
Abstract
Chromosomes underlie a dynamic organization that fulfills functional roles in processes like transcription, DNA repair, nuclear envelope stability, and cell division. Chromosome dynamics depend on chromosome structure and cannot freely diffuse. Furthermore, chromosomes interact closely with their surrounding nuclear environment, which further constrains chromosome dynamics. Recently, several studies enlighten that cytoskeletal proteins regulate dynamic chromosome organization. Cytoskeletal polymers that include actin filaments, microtubules and intermediate filaments can connect to the nuclear envelope via Linker of the Nucleoskeleton and Cytoskeleton (LINC) complexes and transfer forces onto chromosomes inside the nucleus. Monomers of these cytoplasmic polymers and related proteins can also enter the nucleus and play different roles in the interior of the nucleus than they do in the cytoplasm. Nuclear cytoskeletal proteins can act as chromatin remodelers alone or in complexes with other nuclear proteins. They can also act as transcription factors. Many of these mechanisms have been conserved during evolution, indicating that the cytoskeletal regulation of chromosome dynamics is an essential process. In this review, we discuss the different influences of cytoskeletal proteins on chromosome dynamics by focusing on the well-studied model organism budding yeast.
Collapse
Affiliation(s)
- Maya Spichal
- Department of Genetics, University of North Carolina, Chapel HillNC, United States
| | - Emmanuelle Fabre
- Equipe Biologie et Dynamique des Chromosomes, Institut Universitaire d'Hématologie, CNRS UMR 7212, INSERM U944, Hôpital St. Louis 1Paris, France
| |
Collapse
|
30
|
Abstract
Most cells in nature are not actively dividing, yet are able to return to the cell cycle given the appropriate environmental signals. There is now ample evidence that quiescent G0 cells are not shut-down but still metabolically and transcriptionally active. Quiescent cells must maintain a basal transcriptional capacity to maintain transcripts and proteins necessary for survival. This implies a tight control over RNA polymerases: RNA pol II for mRNA transcription during G0, but especially RNA pol I and RNA pol III to maintain an appropriate level of structural RNAs, raising the possibility that specific transcriptional control mechanisms evolved in quiescent cells. In accordance with this, we recently discovered that RNA interference is necessary to control RNA polymerase I transcription during G0. While this mini-review focuses on yeast model organisms (Saccharomyces cerevisiae and Schizosaccharomyces pombe), parallels are drawn to other eukaryotes and mammalian systems, in particular stem cells.
Collapse
Affiliation(s)
- Benjamin Roche
- a Cold Spring Harbor Laboratory , Cold Spring Harbor , NY , USA
| | - Benoit Arcangioli
- b Genome Dynamics Unit , UMR 3525 CNRS, Institut Pasteur, 25-28 rue du Docteur Roux , Paris , France
| | - Robert Martienssen
- a Cold Spring Harbor Laboratory , Cold Spring Harbor , NY , USA.,c Howard Hughes Medical Institute-Gordon and Betty Moore Foundation (HHMI-GBM) Investigator , NY , USA
| |
Collapse
|
31
|
Abstract
Chromosomes underlie a dynamic organization that fulfills functional roles in processes like transcription, DNA repair, nuclear envelope stability, and cell division. Chromosome dynamics depend on chromosome structure and cannot freely diffuse. Furthermore, chromosomes interact closely with their surrounding nuclear environment, which further constrains chromosome dynamics. Recently, several studies enlighten that cytoskeletal proteins regulate dynamic chromosome organization. Cytoskeletal polymers that include actin filaments, microtubules and intermediate filaments can connect to the nuclear envelope via Linker of the Nucleoskeleton and Cytoskeleton (LINC) complexes and transfer forces onto chromosomes inside the nucleus. Monomers of these cytoplasmic polymers and related proteins can also enter the nucleus and play different roles in the interior of the nucleus than they do in the cytoplasm. Nuclear cytoskeletal proteins can act as chromatin remodelers alone or in complexes with other nuclear proteins. They can also act as transcription factors. Many of these mechanisms have been conserved during evolution, indicating that the cytoskeletal regulation of chromosome dynamics is an essential process. In this review, we discuss the different influences of cytoskeletal proteins on chromosome dynamics by focusing on the well-studied model organism budding yeast.
Collapse
Affiliation(s)
- Maya Spichal
- Department of Genetics, University of North Carolina, Chapel HillNC, United States
| | - Emmanuelle Fabre
- Equipe Biologie et Dynamique des Chromosomes, Institut Universitaire d'Hématologie, CNRS UMR 7212, INSERM U944, Hôpital St. Louis 1Paris, France
| |
Collapse
|
32
|
Exploring the power of yeast to model aging and age-related neurodegenerative disorders. Biogerontology 2016; 18:3-34. [PMID: 27804052 DOI: 10.1007/s10522-016-9666-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/24/2016] [Indexed: 12/12/2022]
Abstract
Aging is a multifactorial process determined by molecular, cellular and systemic factors and it is well established that advancing age is a leading risk factor for several neurodegenerative diseases. In fact, the close association of aging and neurodegenerative disorders has placed aging as the greatest social and economic challenge of the 21st century, and age-related diseases have also become a key priority for countries worldwide. The growing need to better understand both aging and neurodegenerative processes has led to the development of simple eukaryotic models amenable for mechanistic studies. Saccharomyces cerevisiae has proven to be an unprecedented experimental model to study the fundamental aspects of aging and to decipher the intricacies of neurodegenerative disorders greatly because the molecular mechanisms underlying these processes are evolutionarily conserved from yeast to human. Moreover, yeast offers several methodological advantages allowing a rapid and relatively easy way of establishing gene-protein-function associations. Here we review different aging theories, common cellular pathways driving aging and neurodegenerative diseases and discuss the major contributions of yeast to the state-of-art knowledge in both research fields.
Collapse
|