1
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Valeeva LR, Abdulkina LR, Agabekian IA, Shakirov EV. Telomere biology and ribosome biogenesis: structural and functional interconnections. Biochem Cell Biol 2023; 101:394-409. [PMID: 36989538 DOI: 10.1139/bcb-2022-0383] [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: 03/31/2023] Open
Abstract
Telomeres are nucleoprotein structures that play a pivotal role in the protection and maintenance of eukaryotic chromosomes. Telomeres and the enzyme telomerase, which replenishes telomeric DNA lost during replication, are important factors necessary to ensure continued cell proliferation. Cell proliferation is also dependent on proper and efficient protein synthesis, which is carried out by ribosomes. Mutations in genes involved in either ribosome biogenesis or telomere biology result in cellular abnormalities and can cause human genetic diseases, defined as ribosomopathies and telomeropathies, respectively. Interestingly, recent discoveries indicate that many of the ribosome assembly and rRNA maturation factors have additional noncanonical functions in telomere biology. Similarly, several key proteins and enzymes involved in telomere biology, including telomerase, have unexpected roles in rRNA transcription and maturation. These observations point to an intriguing cross-talk mechanism potentially explaining the multiple pleiotropic symptoms of mutations in many causal genes identified in various telomeropathy and ribosomopathy diseases. In this review, we provide a brief summary of eukaryotic telomere and rDNA loci structures, highlight several universal features of rRNA and telomerase biogenesis, evaluate intriguing interconnections between telomere biology and ribosome assembly, and conclude with an assessment of overlapping features of human diseases of telomeropathies and ribosomopathies.
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Affiliation(s)
- Liia R Valeeva
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan 420008, Republic of Tatarstan, Russia
- Department of Biological Sciences, College of Science, Marshall University, Huntington, WV 25701, USA
| | - Liliia R Abdulkina
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan 420008, Republic of Tatarstan, Russia
| | - Inna A Agabekian
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan 420008, Republic of Tatarstan, Russia
| | - Eugene V Shakirov
- Department of Biological Sciences, College of Science, Marshall University, Huntington, WV 25701, USA
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA
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2
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Deshpande N, Bryk M. Diverse and dynamic forms of gene regulation by the S. cerevisiae histone methyltransferase Set1. Curr Genet 2023; 69:91-114. [PMID: 37000206 DOI: 10.1007/s00294-023-01265-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 03/11/2023] [Accepted: 03/14/2023] [Indexed: 04/01/2023]
Abstract
Gene transcription is an essential and highly regulated process. In eukaryotic cells, the structural organization of nucleosomes with DNA wrapped around histone proteins impedes transcription. Chromatin remodelers, transcription factors, co-activators, and histone-modifying enzymes work together to make DNA accessible to RNA polymerase. Histone lysine methylation can positively or negatively regulate gene transcription. Methylation of histone 3 lysine 4 by SET-domain-containing proteins is evolutionarily conserved from yeast to humans. In higher eukaryotes, mutations in SET-domain proteins are associated with defects in the development and segmentation of embryos, skeletal and muscle development, and diseases, including several leukemias. Since histone methyltransferases are evolutionarily conserved, the mechanisms of gene regulation mediated by these enzymes are also conserved. Budding yeast Saccharomyces cerevisiae is an excellent model system to study the impact of histone 3 lysine 4 (H3K4) methylation on eukaryotic gene regulation. Unlike larger eukaryotes, yeast cells have only one enzyme that catalyzes H3K4 methylation, Set1. In this review, we summarize current knowledge about the impact of Set1-catalyzed H3K4 methylation on gene transcription in S. cerevisiae. We describe the COMPASS complex, factors that influence H3K4 methylation, and the roles of Set1 in gene silencing at telomeres and heterochromatin, as well as repression and activation at euchromatic loci. We also discuss proteins that "read" H3K4 methyl marks to regulate transcription and summarize alternate functions for Set1 beyond H3K4 methylation.
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Affiliation(s)
- Neha Deshpande
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Mary Bryk
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA.
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Di Nisio E, Danovska S, Condemi L, Cirigliano A, Rinaldi T, Licursi V, Negri R. H3 Lysine 4 Methylation Is Required for Full Activation of Genes Involved in α-Ketoglutarate Availability in the Nucleus of Yeast Cells after Diauxic Shift. Metabolites 2023; 13:metabo13040507. [PMID: 37110165 PMCID: PMC10146420 DOI: 10.3390/metabo13040507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
We show that in S. cerevisiae the metabolic diauxic shift is associated with a H3 lysine 4 tri-methylation (H3K4me3) increase which involves a significant fraction of transcriptionally induced genes which are required for the metabolic changes, suggesting a role for histone methylation in their transcriptional regulation. We show that histone H3K4me3 around the start site correlates with transcriptional induction in some of these genes. Among the methylation-induced genes are IDP2 and ODC1, which regulate the nuclear availability of α-ketoglutarate, which, as a cofactor for Jhd2 demethylase, regulates H3K4 tri-methylation. We propose that this feedback circuit could be used to regulate the nuclear α-ketoglutarate pool concentration. We also show that yeast cells adapt to the absence of Jhd2 by decreasing Set1 methylation activity.
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Chou KY, Lee JY, Kim KB, Kim E, Lee HS, Ryu HY. Histone modification in Saccharomyces cerevisiae: A review of the current status. Comput Struct Biotechnol J 2023; 21:1843-1850. [PMID: 36915383 PMCID: PMC10006725 DOI: 10.1016/j.csbj.2023.02.037] [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: 11/15/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 02/26/2023] Open
Abstract
The budding yeast Saccharomyces cerevisiae is a well-characterized and popular model system for investigating histone modifications and the inheritance of chromatin states. The data obtained from this model organism have provided essential and critical information for understanding the complexity of epigenetic interactions and regulation in eukaryotes. Recent advances in biotechnology have facilitated the detection and quantitation of protein post-translational modification (PTM), including acetylation, methylation, phosphorylation, ubiquitylation, sumoylation, and acylation, and led to the identification of several novel modification sites in histones. Determining the cellular function of these new histone markers is essential for understanding epigenetic mechanisms and their impact on various biological processes. In this review, we describe recent advances and current views on histone modifications and their effects on chromatin dynamics in S. cerevisiae.
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Key Words
- AdoMet, S-adenosylmethionine
- CAF-1, chromatin assembly factor-1
- CTD, C-terminal domain
- DSB, double-strand break
- E Glu, glutamic acid
- HAT, histone acetyltransferase
- HDAC, histone deacetylase
- Histone acetylation
- Histone acylation
- Histone methylation
- Histone phosphorylation
- Histone sumoylation
- Histone ubiquitylation
- JMJC, Jumonji C
- K Lys, lysine
- PTM, post-translational modification
- R Arg, arginine
- S, serine
- SAGA, Spt-Ada-Gcn5 acetyltransferase
- STUbL, SUMO-targeted ubiquitin ligase
- SUMO, small ubiquitin-like modifier
- T, threonine
- Y, tyrosine
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Affiliation(s)
- Kwon Young Chou
- School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jun-Yeong Lee
- BK21 Plus KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Kee-Beom Kim
- BK21 Plus KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Eunjeong Kim
- BK21 Plus KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hyun-Shik Lee
- BK21 Plus KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hong-Yeoul Ryu
- BK21 Plus KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
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Lim S, Liu Y, Rhie BH, Kim C, Ryu HY, Ahn SH. Sus1 maintains a normal lifespan through regulation of TREX-2 complex-mediated mRNA export. Aging (Albany NY) 2022; 14:4990-5012. [PMID: 35771153 PMCID: PMC9271307 DOI: 10.18632/aging.204146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/14/2022] [Indexed: 11/29/2022]
Abstract
Eukaryotic gene expression requires multiple cellular events, including transcription and RNA processing and transport. Sus1, a common subunit in both the Spt-Ada-Gcn5 acetyltransferase (SAGA) and transcription and export complex-2 (TREX-2) complexes, is a key factor in coupling transcription activation to mRNA nuclear export. Here, we report that the SAGA DUB module and TREX-2 distinctly regulate yeast replicative lifespan in a Sir2-dependent and -independent manner, respectively. The growth and lifespan impaired by SUS1 loss depend on TREX-2 but not on the SAGA DUB module. Notably, an increased dose of the mRNA export factors Mex67 and Dbp5 rescues the growth defect, shortened lifespan, and nuclear accumulation of poly(A)+ RNA in sus1Δ cells, suggesting that boosting the mRNA export process restores the mRNA transport defect and the growth and lifespan damage in sus1Δ cells. Moreover, Sus1 is required for the proper association of Mex67 and Dbp5 with the nuclear rim. Together, these data indicate that Sus1 links transcription and mRNA nuclear export to the lifespan control pathway, suggesting that prevention of an abnormal accumulation of nuclear RNA is necessary for maintenance of a normal lifespan.
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Affiliation(s)
- Suji Lim
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Gyeonggi-do 15588, Republic of Korea
| | - Yan Liu
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Gyeonggi-do 15588, Republic of Korea
| | - Byung-Ho Rhie
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Gyeonggi-do 15588, Republic of Korea
| | - Chun Kim
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Gyeonggi-do 15588, Republic of Korea
| | - Hong-Yeoul Ryu
- BK21 Plus KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Seong Hoon Ahn
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Gyeonggi-do 15588, Republic of Korea
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Oh J, Yeom S, Park J, Lee JS. The regional sequestration of heterochromatin structural proteins is critical to form and maintain silent chromatin. Epigenetics Chromatin 2022; 15:5. [PMID: 35101096 PMCID: PMC8805269 DOI: 10.1186/s13072-022-00435-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 01/06/2022] [Indexed: 12/20/2022] Open
Abstract
Budding yeast Saccharomyces cerevisiae and fission yeast Schizosaccharomyces pombe are good models for heterochromatin study. In S. pombe, H3K9 methylation and Swi6, an ortholog of mammalian HP1, lead to heterochromatin formation. However, S. cerevisiae does not have known epigenetic silencing markers and instead has Sir proteins to regulate silent chromatin formation. Although S. cerevisiae and S. pombe form and maintain heterochromatin via mechanisms that appear to be fundamentally different, they share important common features in the heterochromatin structural proteins. Heterochromatin loci are localized at the nuclear periphery by binding to perinuclear membrane proteins, thereby producing distinct heterochromatin foci, which sequester heterochromatin structural proteins. In this review, we discuss the nuclear peripheral anchoring of heterochromatin foci and its functional relevance to heterochromatin formation and maintenance.
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Affiliation(s)
- Junsoo Oh
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, 1 Kangwondeahak-gil, Chuncheon, 24341, Republic of Korea
| | - Soojin Yeom
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, 1 Kangwondeahak-gil, Chuncheon, 24341, Republic of Korea
| | - Jiyeon Park
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, 1 Kangwondeahak-gil, Chuncheon, 24341, Republic of Korea
| | - Jung-Shin Lee
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, 1 Kangwondeahak-gil, Chuncheon, 24341, Republic of Korea.
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7
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Trans-tail regulation-mediated suppression of cryptic transcription. Exp Mol Med 2021; 53:1683-1688. [PMID: 34845331 PMCID: PMC8639711 DOI: 10.1038/s12276-021-00711-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 01/08/2023] Open
Abstract
Crosstalk between post-translational modifications of histone proteins influences the regulation of chromatin structure and gene expression. Among such crosstalk pathways, the best-characterized example is H2B monoubiquitination-mediated H3K4 and H3K79 methylation, which is referred to as trans-tail regulation. Although many studies have investigated the fragmentary effects of this pathway on silencing and transcription, its ultimate contribution to transcriptional control has remained unclear. Recent advances in molecular techniques and genomics have, however, revealed that the trans-tail crosstalk is linked to a more diverse cascade of histone modifications and has various functions in cotranscriptional processes. Furthermore, H2B monoubiquitination sequentially facilitates H3K4 dimethylation and histone sumoylation, thereby providing a binding platform for recruiting Set3 complex proteins, including two histone deacetylases, to restrict cryptic transcription from gene bodies. The removal of both ubiquitin and SUMO, small ubiquitin-like modifier, modifications from histones also facilitates a change in the phosphorylation pattern of the RNA polymerase II C-terminal domain that is required for subsequent transcriptional elongation. Therefore, this review describes recent findings regarding trans-tail regulation-driven processes to elaborate on their contribution to maintaining transcriptional fidelity. Crosstalk between different DNA-winding proteins, or histones, is a mechanism of molecular fidelity that helps prevent the initiation of aberrant gene expression, which may contribute to cancer and neurodegenerative disease. A team from South Korea, led by Jungmin Choi from the Korea University College of Medicine in Seoul and Hong-Yeoul Ryu from Kyungpook National University in Daegu, review the ways in which different histone proteins chemically modify parts of each other’s structure to regulate their functions. These modifications affect how histones interact with DNA, which in turn alters the dynamics of other factors implicated in gene expression. The correct interaction of histones is necessary to prevent the gene expression machinery from starting RNA synthesis from the wrong sites. Accurate control of these mechanisms is essential for cellular wellbeing
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Lim S, Ahn H, Duan R, Liu Y, Ryu HY, Ahn SH. The Spt7 subunit of the SAGA complex is required for the regulation of lifespan in both dividing and nondividing yeast cells. Mech Ageing Dev 2021; 196:111480. [PMID: 33831401 DOI: 10.1016/j.mad.2021.111480] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/23/2021] [Accepted: 03/31/2021] [Indexed: 11/30/2022]
Abstract
Spt7 belongs to the suppressor of Ty (SPT) module of the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex and is known as the yeast ortholog of human STAF65γ. Spt7 lacks intrinsic enzymatic activity but is responsible for the integrity and proper assembly of the SAGA complex. Here, we determined the role of the SAGA Spt7 subunit in cellular aging. We found that Spt7 was indispensable for a normal lifespan in both dividing and nondividing yeast cells. In the quiescent state of cells, Spt7 was required for the control of overall mRNA levels. In mitotically active cells, deletion of the SPT module had little effect on the recombination rate within heterochromatic ribosomal DNA (rDNA) loci, but loss of Spt7 profoundly elevated the plasmid-based DNA recombination frequency. Consistently, loss of Spt7 increased spontaneous Rad52 foci by approximately two-fold upon entry into S phase. These results provide evidence that Spt7 contributes to the regulation of the normal replicative lifespan (RLS) and chronological lifespan (CLS), possibly by controlling the DNA recombination rate and overall mRNA expression. We propose that the regulation of SAGA complex integrity by Spt7 might be involved in the conserved regulatory pathway for lifespan regulation in eukaryotes.
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Affiliation(s)
- Suji Lim
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University ERICA Campus, Ansan 15588, Republic of Korea
| | - Hyojeong Ahn
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University ERICA Campus, Ansan 15588, Republic of Korea
| | - Ruxin Duan
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University ERICA Campus, Ansan 15588, Republic of Korea
| | - Yan Liu
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University ERICA Campus, Ansan 15588, Republic of Korea
| | - Hong-Yeoul Ryu
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, College of National Sciences, Kyungpook National University, Daegu 41566, Republic of Korea.
| | - Seong Hoon Ahn
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University ERICA Campus, Ansan 15588, Republic of Korea.
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Kumanski S, Viart BT, Kossida S, Moriel-Carretero M. Lipid Droplets Are a Physiological Nucleoporin Reservoir. Cells 2021; 10:472. [PMID: 33671805 PMCID: PMC7926788 DOI: 10.3390/cells10020472] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 02/09/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022] Open
Abstract
Lipid Droplets (LD) are dynamic organelles that originate in the Endoplasmic Reticulum and mostly bud off toward the cytoplasm, where they store neutral lipids for energy and protection purposes. LD also have diverse proteins on their surface, many of which are necessary for the their correct homeostasis. However, these organelles also act as reservoirs of proteins that can be made available elsewhere in the cell. In this sense, they act as sinks that titrate key regulators of many cellular processes. Among the specialized factors that reside on cytoplasmic LD are proteins destined for functions in the nucleus, but little is known about them and their impact on nuclear processes. By screening for nuclear proteins in publicly available LD proteomes, we found that they contain a subset of nucleoporins from the Nuclear Pore Complex (NPC). Exploring this, we demonstrate that LD act as a physiological reservoir, for nucleoporins, that impacts the conformation of NPCs and hence their function in nucleo-cytoplasmic transport, chromatin configuration, and genome stability. Furthermore, our in silico modeling predicts a role for LD-released fatty acids in regulating the transit of nucleoporins from LD through the cytoplasm and to nuclear pores.
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Affiliation(s)
- Sylvain Kumanski
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, Centre National de la Recherche Scientifique, 34293 Montpellier CEDEX 05, France;
| | - Benjamin T. Viart
- International ImMunoGeneTics Information System (IMGT®), Institut de Génétique Humaine (IGH), Université de Montpellier, Centre National de la Recherche Scientifique, 34396 Montpellier CEDEX 05, France; (B.T.V.); (S.K.)
| | - Sofia Kossida
- International ImMunoGeneTics Information System (IMGT®), Institut de Génétique Humaine (IGH), Université de Montpellier, Centre National de la Recherche Scientifique, 34396 Montpellier CEDEX 05, France; (B.T.V.); (S.K.)
| | - María Moriel-Carretero
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, Centre National de la Recherche Scientifique, 34293 Montpellier CEDEX 05, France;
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Ryu HY, Zhao D, Li J, Su D, Hochstrasser M. Histone sumoylation promotes Set3 histone-deacetylase complex-mediated transcriptional regulation. Nucleic Acids Res 2020; 48:12151-12168. [PMID: 33231641 PMCID: PMC7708062 DOI: 10.1093/nar/gkaa1093] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 10/12/2020] [Accepted: 10/27/2020] [Indexed: 12/02/2022] Open
Abstract
Histones are substrates of the SUMO (small ubiquitin-like modifier) conjugation pathway. Several reports suggest histone sumoylation affects transcription negatively, but paradoxically, our genome-wide analysis shows the modification concentrated at many active genes. We find that trans-tail regulation of histone-H2B ubiquitylation and H3K4 di-methylation potentiates subsequent histone sumoylation. Consistent with the known control of the Set3 histone deacetylase complex (HDAC) by H3K4 di-methylation, histone sumoylation directly recruits the Set3 complex to both protein-coding and noncoding RNA (ncRNA) genes via a SUMO-interacting motif in the HDAC Cpr1 subunit. The altered gene expression profile caused by reducing histone sumoylation matches well to the profile in cells lacking Set3. Histone H2B sumoylation and the Set3 HDAC coordinately suppress cryptic ncRNA transcription initiation internal to mRNA genes. Our results reveal an elaborate co-transcriptional histone crosstalk pathway involving the consecutive ubiquitylation, methylation, sumoylation and deacetylation of histones, which maintains transcriptional fidelity by suppressing spurious transcription.
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Affiliation(s)
- Hong-Yeoul Ryu
- Correspondence may also be addressed to Hong-Yeoul Ryu. Tel: +82 53 950 6352;
| | - Dejian Zhao
- Yale Center for Genome Analysis, Yale University, New Haven, CT 06520, USA
| | - Jianhui Li
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Dan Su
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
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Epigenetic Mechanisms Contribute to Evolutionary Adaptation of Gene Network Activity under Environmental Selection. Cell Rep 2020; 33:108306. [PMID: 33113358 PMCID: PMC7656290 DOI: 10.1016/j.celrep.2020.108306] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/17/2019] [Accepted: 10/02/2020] [Indexed: 11/30/2022] Open
Abstract
How evolution can be facilitated by epigenetic mechanisms has received refreshed attention recently. To explore the role epigenetic inheritance plays in evolution, we subject isogenic wild-type yeast cells expressing PGAL1-YFP (yellow fluorescent protein) to selection by daily sorting based on reporter expression. We observe expression-level reductions in multiple replicates sorted for the lowest expression that persist for several days, even after lifting the selection pressure. Reduced expression is due to factors in the galactose (GAL) network rather than global factors. Results using a constitutively active GAL network are in overall agreement with findings with the wild-type network. We find that the local chromatin environment of the reporter has a significant effect on the observed phenotype. Genome sequencing, chromatin immunoprecipitation (ChIP)-qPCR, and sporulation analysis provide further insights into the epigenetic and genetic contributors to the expression changes observed. Our work provides a comprehensive example of the role played by epigenetic mechanisms on gene network evolution. Luo et al. demonstrate how epigenetic mechanisms contribute to the evolution of gene network activity. Subjecting yeast cells to repeated environmental selection based on the activity of the galactose network, they observe sustained changes in reporter expression level. They characterize the epigenetic and genetic factors contributing to the observed phenotypes.
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12
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Hou J, Feng HQ, Chang HW, Liu Y, Li GH, Yang S, Sun CH, Zhang MZ, Yuan Y, Sun J, Zhu-Salzman K, Zhang H, Qin QM. The H3K4 demethylase Jar1 orchestrates ROS production and expression of pathogenesis-related genes to facilitate Botrytis cinerea virulence. THE NEW PHYTOLOGIST 2020; 225:930-947. [PMID: 31529514 DOI: 10.1111/nph.16200] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
Histone 3 Lysine 4 (H3K4) demethylation is ubiquitous in organisms, however the roles of H3K4 demethylase JARID1(Jar1)/KDM5 in fungal development and pathogenesis remain largely unexplored. Here, we demonstrate that Jar1/KDM5 in Botrytis cinerea, the grey mould fungus, plays a crucial role in these processes. The BcJAR1 gene was deleted and its roles in fungal development and pathogenesis were investigated using approaches including genetics, molecular/cell biology, pathogenicity and transcriptomic profiling. BcJar1 regulates H3K4me3 and both H3K4me2 and H3K4me3 methylation levels during vegetative and pathogenic development, respectively. Loss of BcJAR1 impairs conidiation, appressorium formation and stress adaptation; abolishes infection cushion (IC) formation and virulence, but promotes sclerotium production in the ΔBcjar1 mutants. BcJar1 controls reactive oxygen species (ROS) production and proper assembly of Sep4, a core septin protein and virulence determinant, to initiate infection structure (IFS) formation and host penetration. Exogenous cAMP partially restored the mutant appressorium, but not IC, formation. BcJar1 orchestrates global expression of genes for ROS production, stress response, carbohydrate transmembrane transport, secondary metabolites, etc., which may be required for conidiation, IFS formation, host penetration and virulence of the pathogen. Our work systematically elucidates BcJar1 functions and provides novel insights into Jar1/KDM5-mediated H3K4 demethylation in regulating fungal development and pathogenesis.
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Affiliation(s)
- Jie Hou
- College of Plant Sciences, Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China
- College of Forestry, BeiHua University, Jilin, 132013, China
| | - Hui-Qiang Feng
- College of Plant Sciences, Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China
| | - Hao-Wu Chang
- Key Laboratory of Symbolic Computation and Knowledge Engineering, Ministry of Education, College of Computer Science and Technology, Jilin University, Changchun, 130012, China
| | - Yue Liu
- College of Plant Sciences, Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China
| | - Gui-Hua Li
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Song Yang
- College of Plant Sciences, Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China
| | - Chen-Hao Sun
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Ming-Zhe Zhang
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Ye Yuan
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Jiao Sun
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Keyan Zhu-Salzman
- Department of Entomology, Texas A&M University, College Station, TX, 77843, USA
| | - Hao Zhang
- Key Laboratory of Symbolic Computation and Knowledge Engineering, Ministry of Education, College of Computer Science and Technology, Jilin University, Changchun, 130012, China
| | - Qing-Ming Qin
- College of Plant Sciences, Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China
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Duan R, Ryu HY, Ahn SH. Symmetric dimethylation on histone H4R3 associates with histone deacetylation to maintain properly polarized cell growth. Res Microbiol 2019; 171:91-98. [PMID: 31574302 DOI: 10.1016/j.resmic.2019.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 08/20/2019] [Accepted: 09/24/2019] [Indexed: 12/12/2022]
Abstract
Yeast Hsl7 is recognized as a homolog of human arginine methyltransferase 5 (PRMT5) and shows type II PRMT activity by forming symmetric dimethylarginine residues on histones. Previously, we reported that Hsl7 is responsible for in vivo symmetric dimethylation on histone H4 arginine 3 (H4R3me2s) in a transcriptionally repressed state, possibly in association with histone deacetylation by Rpd3. Here, we investigated the function of Hsl7 during cell cycle progression. We found that the accumulation of Hsl7-mediated H4R3me2s is maintained by the histone deacetylase Rpd3 during transcriptional repression and that the low level of H4R3me2s is required for proper asymmetric cell growth during cell division. Our results suggest that the hypoacetylated state of histones is connected to the function of Hsl7 in regulating properly polarized cell growth during cell division and provide new insight into the epigenetic modifications that are important for cell cycle morphogenesis checkpoint control based on the repressive histone crosstalk between symmetric arginine methylation of H4 and histone deacetylation.
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Affiliation(s)
- Ruxin Duan
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Republic of Korea
| | - Hong-Yeoul Ryu
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Republic of Korea
| | - Seong Hoon Ahn
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Republic of Korea.
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14
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Ryu H, Su D, Wilson‐Eisele NR, Zhao D, López‐Giráldez F, Hochstrasser M. The Ulp2 SUMO protease promotes transcription elongation through regulation of histone sumoylation. EMBO J 2019; 38:e102003. [PMID: 31313851 PMCID: PMC6694223 DOI: 10.15252/embj.2019102003] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/22/2019] [Accepted: 06/26/2019] [Indexed: 01/07/2023] Open
Abstract
Many eukaryotic proteins are regulated by modification with the ubiquitin-like protein small ubiquitin-like modifier (SUMO). This linkage is reversed by SUMO proteases, of which there are two in Saccharomyces cerevisiae, Ulp1 and Ulp2. SUMO-protein conjugation regulates transcription, but the roles of SUMO proteases in transcription remain unclear. We report that Ulp2 is recruited to transcriptionally active genes to control local polysumoylation. Mutant ulp2 cells show impaired association of RNA polymerase II (RNAPII) with, and diminished expression of, constitutively active genes and the inducible CUP1 gene. Ulp2 loss sensitizes cells to 6-azauracil, a hallmark of transcriptional elongation defects. We also describe a novel chromatin regulatory mechanism whereby histone-H2B ubiquitylation stimulates histone sumoylation, which in turn appears to inhibit nucleosome association of the Ctk1 kinase. Ctk1 phosphorylates serine-2 (S2) in the RNAPII C-terminal domain (CTD) and promotes transcript elongation. Removal of both ubiquitin and SUMO from histones is needed to overcome the impediment to S2 phosphorylation. These results suggest sequential ubiquitin-histone and SUMO-histone modifications recruit Ulp2, which removes polySUMO chains and promotes RNAPII transcription elongation.
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Affiliation(s)
- Hong‐Yeoul Ryu
- Department of Molecular Biophysics and BiochemistryYale UniversityNew HavenCTUSA
| | - Dan Su
- Department of Molecular Biophysics and BiochemistryYale UniversityNew HavenCTUSA
- Present address:
Protein Science Corp.MeridenCTUSA
| | - Nicole R Wilson‐Eisele
- Department of Molecular Biophysics and BiochemistryYale UniversityNew HavenCTUSA
- Present address:
Max Planck Institute of BiochemistryMartinsriedGermany
| | - Dejian Zhao
- Yale Center for Genome AnalysisYale UniversityNew HavenCTUSA
| | | | - Mark Hochstrasser
- Department of Molecular Biophysics and BiochemistryYale UniversityNew HavenCTUSA
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15
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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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16
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Lukito Y, Chujo T, Hale TK, Mace W, Johnson LJ, Scott B. Regulation of subtelomeric fungal secondary metabolite genes by H3K4me3 regulators CclA and KdmB. Mol Microbiol 2019; 112:837-853. [DOI: 10.1111/mmi.14320] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Yonathan Lukito
- Institute of Fundamental Sciences Massey University Palmerston North New Zealand
- Grasslands Research Centre AgResearch Limited Palmerston North New Zealand
| | - Tetsuya Chujo
- Institute of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Tracy K. Hale
- Institute of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Wade Mace
- Grasslands Research Centre AgResearch Limited Palmerston North New Zealand
| | - Linda J. Johnson
- Grasslands Research Centre AgResearch Limited Palmerston North New Zealand
| | - Barry Scott
- Institute of Fundamental Sciences Massey University Palmerston North New Zealand
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17
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Ryu HY, Duan R, Ahn SH. Yeast symmetric arginine methyltransferase Hsl7 has a repressive role in transcription. Res Microbiol 2019; 170:222-229. [PMID: 30660775 DOI: 10.1016/j.resmic.2019.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/29/2018] [Accepted: 01/09/2019] [Indexed: 12/17/2022]
Abstract
Protein arginine methylation, an evolutionarily conserved post-translational modification, serves critical cellular functions by transferring a methyl group to a variety of substrates, including histones and some transcription factors. In budding yeast, Hsl7 (histone synthetic lethal 7) displays type II PRMT (protein arginine methyltransferase) activity by generating symmetric dimethylarginine residues on histone H2A in vitro. However, identification of the in vivo substrate of Hsl7 and how it contributes to important cellular processes remain largely unexplored. In the present study, we show that Hsl7 has a repressive role in transcription. We found that Hsl7 is responsible for in vivo symmetric dimethylation of histone H4 arginine 3 (H4R3me2s) in a transcriptionally repressed state. Tandem affinity purification further demonstrated that Hsl7 physically interacts with histone deacetylase Rpd3, and both similarly repress transcription. Our results suggest that H4R3me2s generation by the type II PRMT Hsl7 is required for transcriptional repression, possibly in cooperation with histone deacetylation by Rpd3.
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Affiliation(s)
- Hong-Yeoul Ryu
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Republic of Korea
| | - Ruxin Duan
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Republic of Korea
| | - Seong Hoon Ahn
- Department of Molecular and Life Science, College of Science and Convergence Technology, Hanyang University, Ansan, Republic of Korea.
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18
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Ryu HY, López-Giráldez F, Knight J, Hwang SS, Renner C, Kreft SG, Hochstrasser M. Distinct adaptive mechanisms drive recovery from aneuploidy caused by loss of the Ulp2 SUMO protease. Nat Commun 2018; 9:5417. [PMID: 30575729 PMCID: PMC6303320 DOI: 10.1038/s41467-018-07836-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 11/27/2018] [Indexed: 12/22/2022] Open
Abstract
In response to acute loss of the Ulp2 SUMO-specific protease, yeast become disomic for chromosome I (ChrI) and ChrXII. Here we report that ChrI disomy, which creates an adaptive advantage in part by increasing the dosage of the Ccr4 deadenylase, was eliminated by extended passaging. Loss of aneuploidy is often accompanied by mutations in essential SUMO-ligating enzymes, which reduced polySUMO-conjugate accumulation. The mRNA levels for almost all ribosomal proteins increase transiently upon initial loss of Ulp2, but elevated Ccr4 levels limit excess ribosome formation. Notably, extended passaging leads to increased levels of many small nucleolar RNAs (snoRNAs) involved in ribosome biogenesis, and higher dosage of three linked ChrXII snoRNA genes suppressed ChrXII disomy in ulp2Δ cells. Our data reveal that aneuploidy allows rapid adaptation to Ulp2 loss, but long-term adaptation restores euploidy. Cellular evolution restores homeostasis through countervailing mutations in SUMO-modification pathways and regulatory shifts in ribosome biogenesis.
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Affiliation(s)
- Hong-Yeoul Ryu
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, 06520, USA
| | | | - James Knight
- Yale Center for Genome Analysis, Yale University, New Haven, CT, 06520, USA
| | - Soo Seok Hwang
- Department of Immunobiology, Yale University, New Haven, CT, 06520, USA
| | - Christina Renner
- Department of Biology, Molecular Microbiology, University of Konstanz, Universitaetsstrasse 10, 78457, Konstanz, Germany
| | - Stefan G Kreft
- Department of Biology, Molecular Microbiology, University of Konstanz, Universitaetsstrasse 10, 78457, Konstanz, Germany
| | - Mark Hochstrasser
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, 06520, USA.
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19
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Abstract
Eukaryotic genomes are packaged in chromatin. The higher-order organization of nucleosome core particles is controlled by the association of the intervening linker DNA with either the linker histone H1 or high mobility group box (HMGB) proteins. While H1 is thought to stabilize the nucleosome by preventing DNA unwrapping, the DNA bending imposed by HMGB may propagate to the nucleosome to destabilize chromatin. For metazoan H1, chromatin compaction requires its lysine-rich C-terminal domain, a domain that is buried between globular domains in the previously characterized yeast Saccharomyces cerevisiae linker histone Hho1p. Here, we discuss the functions of S. cerevisiae HMO1, an HMGB family protein unique in containing a terminal lysine-rich domain and in stabilizing genomic DNA. On ribosomal DNA (rDNA) and genes encoding ribosomal proteins, HMO1 appears to exert its role primarily by stabilizing nucleosome-free regions or "fragile" nucleosomes. During replication, HMO1 likewise appears to ensure low nucleosome density at DNA junctions associated with the DNA damage response or the need for topoisomerases to resolve catenanes. Notably, HMO1 shares with the mammalian linker histone H1 the ability to stabilize chromatin, as evidenced by the absence of HMO1 creating a more dynamic chromatin environment that is more sensitive to nuclease digestion and in which chromatin-remodeling events associated with DNA double-strand break repair occur faster; such chromatin stabilization requires the lysine-rich extension of HMO1. Thus, HMO1 appears to have evolved a unique linker histone-like function involving the ability to stabilize both conventional nucleosome arrays as well as DNA regions characterized by low nucleosome density or the presence of noncanonical nucleosomes.
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20
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Mitochondrial control through nutritionally regulated global histone H3 lysine-4 demethylation. Sci Rep 2016; 6:37942. [PMID: 27897198 PMCID: PMC5126570 DOI: 10.1038/srep37942] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 11/02/2016] [Indexed: 12/13/2022] Open
Abstract
Histone demethylation by Jumonji-family proteins is coupled with the decarboxylation of α-ketoglutarate (αKG) to yield succinate, prompting hypotheses that their activities are responsive to levels of these metabolites in the cell. Consistent with this paradigm we show here that the Saccharomyces cerevisiae Jumonji demethylase Jhd2 opposes the accumulation of H3K4me3 in fermenting cells only when they are nutritionally manipulated to contain an elevated αKG/succinate ratio. We also find that Jhd2 opposes H3K4me3 in respiratory cells that do not exhibit such an elevated αKG/succinate ratio. While jhd2∆ caused only limited gene expression defects in fermenting cells, transcript profiling and physiological measurements show that JHD2 restricts mitochondrial respiratory capacity in cells grown in non-fermentable carbon in an H3K4me-dependent manner. In association with these phenotypes, we find that JHD2 limits yeast proliferative capacity under physiologically challenging conditions as measured by both replicative lifespan and colony growth on non-fermentable carbon. JHD2’s impact on nutrient response may reflect an ancestral role of its gene family in mediating mitochondrial regulation.
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21
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Shyian M, Mattarocci S, Albert B, Hafner L, Lezaja A, Costanzo M, Boone C, Shore D. Budding Yeast Rif1 Controls Genome Integrity by Inhibiting rDNA Replication. PLoS Genet 2016; 12:e1006414. [PMID: 27820830 PMCID: PMC5098799 DOI: 10.1371/journal.pgen.1006414] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 10/10/2016] [Indexed: 12/27/2022] Open
Abstract
The Rif1 protein is a negative regulator of DNA replication initiation in eukaryotes. Here we show that budding yeast Rif1 inhibits DNA replication initiation at the rDNA locus. Absence of Rif1, or disruption of its interaction with PP1/Glc7 phosphatase, leads to more intensive rDNA replication. The effect of Rif1-Glc7 on rDNA replication is similar to that of the Sir2 deacetylase, and the two would appear to act in the same pathway, since the rif1Δ sir2Δ double mutant shows no further increase in rDNA replication. Loss of Rif1-Glc7 activity is also accompanied by an increase in rDNA repeat instability that again is not additive with the effect of sir2Δ. We find, in addition, that the viability of rif1Δ cells is severely compromised in combination with disruption of the MRX or Ctf4-Mms22 complexes, both of which are implicated in stabilization of stalled replication forks. Significantly, we show that removal of the rDNA replication fork barrier (RFB) protein Fob1, alleviation of replisome pausing by deletion of the Tof1/Csm3 complex, or a large deletion of the rDNA repeat array all rescue this synthetic growth defect of rif1Δ cells lacking in addition either MRX or Ctf4-Mms22 activity. These data suggest that the repression of origin activation by Rif1-Glc7 is important to avoid the deleterious accumulation of stalled replication forks at the rDNA RFB, which become lethal when fork stability is compromised. Finally, we show that Rif1-Glc7, unlike Sir2, has an important effect on origin firing outside of the rDNA locus that serves to prevent activation of the DNA replication checkpoint. Our results thus provide insights into a mechanism of replication control within a large repetitive chromosomal domain and its importance for the maintenance of genome stability. These findings may have important implications for metazoans, where large blocks of repetitive sequences are much more common.
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Affiliation(s)
- Maksym Shyian
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Stefano Mattarocci
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Benjamin Albert
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Lukas Hafner
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Aleksandra Lezaja
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Michael Costanzo
- University of Toronto, Donnelly Centre, Toronto, Ontario, Canada
| | - Charlie Boone
- University of Toronto, Donnelly Centre, Toronto, Ontario, Canada
| | - David Shore
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
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22
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Ryu HY, Wilson NR, Mehta S, Hwang SS, Hochstrasser M. Loss of the SUMO protease Ulp2 triggers a specific multichromosome aneuploidy. Genes Dev 2016; 30:1881-94. [PMID: 27585592 PMCID: PMC5024685 DOI: 10.1101/gad.282194.116] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 08/02/2016] [Indexed: 01/15/2023]
Abstract
The SUMO protease Ulp2 modulates many of the SUMO-dependent processes in budding yeast. Ryu et al. discovered that cells lacking Ulp2 display a twofold increase in transcript levels across two particular chromosomes: chromosome I (ChrI) and ChrXII. Extra copies of ChrI and ChrXII can be eliminated following reintroduction of ULP2, suggesting that aneuploidy is a reversible adaptive mechanism to counteract loss of the SUMO protease. Post-translational protein modification by the small ubiquitin-related modifier (SUMO) regulates numerous cellular pathways, including transcription, cell division, and genome maintenance. The SUMO protease Ulp2 modulates many of these SUMO-dependent processes in budding yeast. From whole-genome RNA sequencing (RNA-seq), we unexpectedly discovered that cells lacking Ulp2 display a twofold increase in transcript levels across two particular chromosomes: chromosome I (ChrI) and ChrXII. This is due to the two chromosomes being present at twice their normal copy number. An abnormal number of chromosomes, termed aneuploidy, is usually deleterious. However, development of specific aneuploidies allows rapid adaptation to cellular stresses, and aneuploidy characterizes most human tumors. Extra copies of ChrI and ChrXII appear quickly following loss of active Ulp2 and can be eliminated following reintroduction of ULP2, suggesting that aneuploidy is a reversible adaptive mechanism to counteract loss of the SUMO protease. Importantly, increased dosage of two genes on ChrI—CLN3 and CCR4, encoding a G1-phase cyclin and a subunit of the Ccr4–Not deadenylase complex, respectively—suppresses ulp2Δ aneuploidy, suggesting that increased levels of these genes underlie the aneuploidy induced by Ulp2 loss. Our results reveal a complex aneuploidy mechanism that adapts cells to loss of the SUMO protease Ulp2.
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Affiliation(s)
- Hong-Yeoul Ryu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Nicole R Wilson
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Sameet Mehta
- Yale Center for Genome Analysis, Yale University, New Haven, Connecticut 06520, USA
| | - Soo Seok Hwang
- Department of Immunobiology, Yale University, New Haven, Connecticut 06520, USA
| | - Mark Hochstrasser
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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23
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Abstract
Heterochromatin is the transcriptionally repressed portion of eukaryotic chromatin that maintains a condensed appearance throughout the cell cycle. At sites of ribosomal DNA (rDNA) heterochromatin, epigenetic states contribute to gene silencing and genome stability, which are required for proper chromosome segregation and a normal life span. Here, we focus on recent advances in the epigenetic regulation of rDNA silencing in Saccharomyces cerevisiae and in mammals, including regulation by several histone modifications and several protein components associated with the inner nuclear membrane within the nucleolus. Finally, we discuss the perturbations of rDNA epigenetic pathways in regulating cellular aging and in causing various types of diseases.
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24
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Freire-Benéitez V, Price RJ, Buscaino A. The Chromatin of Candida albicans Pericentromeres Bears Features of Both Euchromatin and Heterochromatin. Front Microbiol 2016; 7:759. [PMID: 27242771 PMCID: PMC4871872 DOI: 10.3389/fmicb.2016.00759] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 05/05/2016] [Indexed: 01/06/2023] Open
Abstract
Centromeres, sites of kinetochore assembly, are important for chromosome stability and integrity. Most eukaryotes have regional centromeres epigenetically specified by the presence of the histone H3 variant CENP-A. CENP-A chromatin is often surrounded by pericentromeric regions packaged into transcriptionally silent heterochromatin. Candida albicans, the most common human fungal pathogen, possesses small regional centromeres assembled into CENP-A chromatin. The chromatin state of C. albicans pericentromeric regions is unknown. Here, for the first time, we address this question. We find that C. albicans pericentromeres are assembled into an intermediate chromatin state bearing features of both euchromatin and heterochromatin. Pericentromeric chromatin is associated with nucleosomes that are highly acetylated, as found in euchromatic regions of the genome; and hypomethylated on H3K4, as found in heterochromatin. This intermediate chromatin state is inhibitory to transcription and partially represses expression of proximal genes and inserted marker genes. Our analysis identifies a new chromatin state associated with pericentromeric regions.
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Affiliation(s)
| | - R Jordan Price
- School of Biosciences Canterbury Kent, University of Kent Canterbury, UK
| | - Alessia Buscaino
- School of Biosciences Canterbury Kent, University of Kent Canterbury, UK
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25
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SUMO Pathway Modulation of Regulatory Protein Binding at the Ribosomal DNA Locus in Saccharomyces cerevisiae. Genetics 2016; 202:1377-94. [PMID: 26837752 DOI: 10.1534/genetics.116.187252] [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: 07/30/2015] [Accepted: 01/20/2016] [Indexed: 11/18/2022] Open
Abstract
In this report, we identify cellular targets of Ulp2, one of two Saccharomyces cerevisiae small ubiquitin-related modifier (SUMO) proteases, and investigate the function of SUMO modification of these proteins. PolySUMO conjugates from ulp2Δ and ulp2Δ slx5Δ cells were isolated using an engineered affinity reagent containing the four SUMO-interacting motifs (SIMs) of Slx5, a component of the Slx5/Slx8 SUMO-targeted ubiquitin ligase (STUbL). Two proteins identified, Net1 and Tof2, regulate ribosomal DNA (rDNA) silencing and were found to be hypersumoylated in ulp2Δ,slx5Δ, and ulp2Δ slx5Δ cells. The increase in sumoylation of Net1 and Tof2 in ulp2Δ, but not ulp1ts cells, indicates that these nucleolar proteins are specific substrates of Ulp2 Based on quantitative chromatin-immunoprecipitation assays, both Net1 and Tof2 lose binding to their rDNA sites in ulp2Δ cells and both factors largely regain this association in ulp2Δ slx5Δ A parsimonious interpretation of these results is that hypersumoylation of these proteins causes them to be ubiquitylated by Slx5/Slx8, impairing their association with rDNA. Fob1, a protein that anchors both Net1 and Tof2 to the replication-fork barrier (RFB) in the rDNA repeats, is sumoylated in wild-type cells, and its modification levels increase specifically in ulp2Δ cells. Fob1 experiences a 50% reduction in rDNA binding in ulp2Δ cells, which is also rescued by elimination of Slx5 Additionally, overexpression of Sir2, another RFB-associated factor, suppresses the growth defect of ulp2Δ cells. Our data suggest that regulation of rDNA regulatory proteins by Ulp2 and the Slx5/Slx8 STUbL may be the cause of multiple ulp2Δ cellular defects.
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26
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Wang D, Mansisidor A, Prabhakar G, Hochwagen A. Condensin and Hmo1 Mediate a Starvation-Induced Transcriptional Position Effect within the Ribosomal DNA Array. Cell Rep 2016; 14:1010-1017. [PMID: 26832415 DOI: 10.1016/j.celrep.2016.01.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 10/30/2015] [Accepted: 12/28/2015] [Indexed: 02/06/2023] Open
Abstract
Repetitive DNA arrays are important structural features of eukaryotic genomes that are often heterochromatinized to suppress repeat instability. It is unclear, however, whether all repeats within an array are equally subject to heterochromatin formation and gene silencing. Here, we show that in starving Saccharomyces cerevisiae, silencing of reporter genes within the ribosomal DNA (rDNA) array is less pronounced in outer repeats compared with inner repeats. This position effect is linked to the starvation-induced contraction of the nucleolus. We show that the chromatin regulators condensin and Hmo1 redistribute within the rDNA upon starvation; that Hmo1, like condensin, is required for nucleolar contraction; and that the position effect partially depends on both proteins. Starvation-induced nucleolar contraction and differential desilencing of the outer rDNA repeats may provide a mechanism to activate rDNA-encoded RNAPII transcription units without causing general rDNA instability.
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Affiliation(s)
- Danni Wang
- Department of Biology, New York University, New York, NY 10003, USA
| | | | | | - Andreas Hochwagen
- Department of Biology, New York University, New York, NY 10003, USA.
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27
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Dvořáčková M, Fojtová M, Fajkus J. Chromatin dynamics of plant telomeres and ribosomal genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:18-37. [PMID: 25752316 DOI: 10.1111/tpj.12822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 05/03/2023]
Abstract
Telomeres and genes encoding 45S ribosomal RNA (rDNA) are frequently located adjacent to each other on eukaryotic chromosomes. Although their primary roles are different, they show striking similarities with respect to their features and additional functions. Both genome domains have remarkably dynamic chromatin structures. Both are hypersensitive to dysfunctional histone chaperones, responding at the genomic and epigenomic levels. Both generate non-coding transcripts that, in addition to their epigenetic roles, may induce gross chromosomal rearrangements. Both give rise to chromosomal fragile sites, as their replication is intrinsically problematic. However, at the same time, both are essential for maintenance of genomic stability and integrity. Here we discuss the structural and functional inter-connectivity of telomeres and rDNA, with a focus on recent results obtained in plants.
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Affiliation(s)
- Martina Dvořáčková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
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