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McCullough LL, Pham TH, Parnell TJ, Connell Z, Chandrasekharan MB, Stillman DJ, Formosa T. Establishment and Maintenance of Chromatin Architecture Are Promoted Independently of Transcription by the Histone Chaperone FACT and H3-K56 Acetylation in Saccharomyces cerevisiae. Genetics 2019; 211:877-892. [PMID: 30679261 PMCID: PMC6404263 DOI: 10.1534/genetics.118.301853] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 01/14/2019] [Indexed: 12/16/2022] Open
Abstract
FACT (FAcilitates Chromatin Transcription/Transactions) is a histone chaperone that can destabilize or assemble nucleosomes. Acetylation of histone H3-K56 weakens a histone-DNA contact that is central to FACT activity, suggesting that this modification could affect FACT functions. We tested this by asking how mutations of H3-K56 and FACT affect nucleosome reorganization activity in vitro, and chromatin integrity and transcript output in vivo Mimics of unacetylated or permanently acetylated H3-K56 had different effects on FACT activity as expected, but the same mutations had surprisingly similar effects on global transcript levels. The results are consistent with emerging models that emphasize FACT's importance in establishing global chromatin architecture prior to transcription, promoting transitions among different states as transcription profiles change, and restoring chromatin integrity after it is disturbed. Optimal FACT activity required the availability of both modified and unmodified states of H3-K56. Perturbing this balance was especially detrimental for maintaining repression of genes with high nucleosome occupancy over their promoters and for blocking antisense transcription at the +1 nucleosome. The results reveal a complex collaboration between H3-K56 modification status and multiple FACT functions, and support roles for nucleosome reorganization by FACT before, during, and after transcription.
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Affiliation(s)
- Laura L McCullough
- Department of Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84112
| | - Trang H Pham
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, Utah 84112
| | - Timothy J Parnell
- Department of Oncological Sciences, University of Utah Health Sciences Center, Salt Lake City, Utah 84112
| | - Zaily Connell
- Department of Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84112
| | - Mahesh B Chandrasekharan
- Department of Radiation Oncology, University of Utah Health Sciences Center, Salt Lake City, Utah 84112
| | - David J Stillman
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, Utah 84112
| | - Tim Formosa
- Department of Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84112
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152
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Dobersch S, Rubio K, Barreto G. Pioneer Factors and Architectural Proteins Mediating Embryonic Expression Signatures in Cancer. Trends Mol Med 2019; 25:287-302. [PMID: 30795971 DOI: 10.1016/j.molmed.2019.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/25/2019] [Accepted: 01/25/2019] [Indexed: 12/18/2022]
Abstract
Accumulation of mutations causing aberrant changes in the genome promotes cancer. However, mutations do not occur in every cancer subtype, suggesting additional events that trigger cancer. Chromatin rearrangements initiated by pioneer factors and architectural proteins are key events occurring before cancer-related genes are expressed. Both protein groups are also master regulators of important processes during embryogenesis. Several publications demonstrated that embryonic gene expression signatures are reactivated during cancer. This review article highlights current knowledge on pioneer factors and architectural proteins mediating chromatin rearrangements, which are the backbone of embryonic expression signatures promoting malignant transformation. Understanding chromatin rearrangements inducing embryonic expression signatures in adult cells might be the key to novel therapeutic approaches against cancers subtypes that arise without genomic mutations.
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Affiliation(s)
- Stephanie Dobersch
- Lung Cancer Epigenetic, Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Karla Rubio
- Lung Cancer Epigenetic, Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Guillermo Barreto
- Lung Cancer Epigenetic, Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany; Laboratoire Croissance, Réparation et Régénération Tissulaires (CRRET), CNRS ERL 9215, Université Paris Est Créteil, Université Paris Est, F-94000, Créteil, France; Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 420008 Kazan, Russian Federation; Member of the Excellence Cluster Cardio Pulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), 35932 Giessen, Germany; Member of the German Center of Lung Research (Deutsches Zentrum für Lungenforschung, DZL).
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153
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Transcription-driven chromatin repression of Intragenic transcription start sites. PLoS Genet 2019; 15:e1007969. [PMID: 30707695 PMCID: PMC6373976 DOI: 10.1371/journal.pgen.1007969] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 02/13/2019] [Accepted: 01/16/2019] [Indexed: 12/31/2022] Open
Abstract
Progression of RNA polymerase II (RNAPII) transcription relies on the appropriately positioned activities of elongation factors. The resulting profile of factors and chromatin signatures along transcription units provides a “positional information system” for transcribing RNAPII. Here, we investigate a chromatin-based mechanism that suppresses intragenic initiation of RNAPII transcription. We demonstrate that RNAPII transcription across gene promoters represses their function in plants. This repression is characterized by reduced promoter-specific molecular signatures and increased molecular signatures associated with RNAPII elongation. The conserved FACT histone chaperone complex is required for this repression mechanism. Genome-wide Transcription Start Site (TSS) mapping reveals thousands of discrete intragenic TSS positions in fact mutants, including downstream promoters that initiate alternative transcript isoforms. We find that histone H3 lysine 4 mono-methylation (H3K4me1), an Arabidopsis RNAPII elongation signature, is enriched at FACT-repressed intragenic TSSs. Our analyses suggest that FACT is required to repress intragenic TSSs at positions that are in part characterized by elevated H3K4me1 levels. In sum, conserved and plant-specific chromatin features correlate with the co-transcriptional repression of intragenic TSSs. Our insights into TSS repression by RNAPII transcription promise to inform the regulation of alternative transcript isoforms and the characterization of gene regulation through the act of pervasive transcription across eukaryotic genomes. Genes represent DNA elements that are transcribed into mRNA. However, the position where transcription actually starts can be dynamically regulated to expand the diversity of RNA isoforms produced from a single gene. Functionally, alternative Transcription Start Sites (TSSs) may generate protein isoforms with differing N-terminal regions and distinct cellular functions. In plants, light signaling regulates protein isoforms largely through regulated TSS selection, emphasizing the biological significance of this mechanism. Despite the importance of alternative TSS selection, little is known about the underlying molecular mechanisms. Here, we characterize for the first time how transcription initiation from an upstream promoter represses alternative downstream promoter activity in plants. This repression mechanism is associated with chromatin changes that are required to maintain precise gene expression control. Specific chromatin signatures are established during transcription via dynamic interactions between the transcription machinery and associated factors. The conserved histone chaperone complex FACT is one such factor involved in regulating the chromatin environment along genes during transcription. We find that mutant plants with reduced FACT activity specifically initiate transcription from thousands of intragenic positions, thus expanding RNA isoform diversity. Overall, our study reveals conserved and plant-specific chromatin features associated with the co-transcriptional repression of downstream intragenic TSSs. These findings promise to help inform the molecular mechanism underlying environmentally-triggered TSS regulation in plants.
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154
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Nune M, Morgan MT, Connell Z, McCullough L, Jbara M, Sun H, Brik A, Formosa T, Wolberger C. FACT and Ubp10 collaborate to modulate H2B deubiquitination and nucleosome dynamics. eLife 2019; 8:40988. [PMID: 30681413 PMCID: PMC6372288 DOI: 10.7554/elife.40988] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/24/2019] [Indexed: 12/21/2022] Open
Abstract
Monoubiquitination of histone H2B (H2B-Ub) plays a role in transcription and DNA replication, and is required for normal localization of the histone chaperone, FACT. In yeast, H2B-Ub is deubiquitinated by Ubp8, a subunit of SAGA, and Ubp10. Although they target the same substrate, loss of Ubp8 and Ubp10 cause different phenotypes and alter the transcription of different genes. We show that Ubp10 has poor activity on yeast nucleosomes, but that the addition of FACT stimulates Ubp10 activity on nucleosomes and not on other substrates. Consistent with a role for FACT in deubiquitinating H2B in vivo, a FACT mutant strain shows elevated levels of H2B-Ub. Combination of FACT mutants with deletion of Ubp10, but not Ubp8, confers increased sensitivity to hydroxyurea and activates a cryptic transcription reporter, suggesting that FACT and Ubp10 may coordinate nucleosome assembly during DNA replication and transcription. Our findings reveal unexpected interplay between H2B deubiquitination and nucleosome dynamics.
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Affiliation(s)
- Melesse Nune
- Program in Molecular Biophysics, Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Michael T Morgan
- Program in Molecular Biophysics, Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Zaily Connell
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, United States
| | - Laura McCullough
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, United States
| | - Muhammad Jbara
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Hao Sun
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ashraf Brik
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Tim Formosa
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, United States
| | - Cynthia Wolberger
- Program in Molecular Biophysics, Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, United States
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155
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Biochemical methods to characterize RNA polymerase II elongation complexes. Methods 2019; 159-160:70-81. [PMID: 30684536 DOI: 10.1016/j.ymeth.2019.01.011] [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: 12/03/2018] [Revised: 01/15/2019] [Accepted: 01/21/2019] [Indexed: 02/07/2023] Open
Abstract
Transcription of DNA into RNA is critical for all life, and RNA polymerases are enzymes tasked with this activity. In eukaryotes, RNA Polymerase II (RNAPII) is responsible for transcription of all protein coding genes and many non-coding RNAs. RNAPII carries out the remarkable feat of unwinding the stable double-stranded DNA template, synthesizing the transcript and re-forming the double helix behind it with great precision and speed. In vitro, RNAPII is capable of carrying out templated RNA chain elongation in the absence of any accessory proteins. However, in cells, the transcription of genes is influenced by several factors, including DNA structure, chromatin, co-transcriptional processes, and DNA binding proteins, which impede the smooth progression of RNAPII down the template. Many transcription elongation proteins have evolved to mitigate the complications and barriers encountered by polymerase during transcription. Many of these elongation factors physically interact with components of the RNAPII elongation complex, including the growing RNA transcript and the DNA template entering and exiting RNAPII. To better understand how transcription elongation factors (EFs) regulate RNAPII, elegant methods are required to probe the structure of the elongation complex. Here, we describe a collection of biochemical assays to interrogate the structure of the RNAPII elongation complex of Saccharomyces cerevisiae that are capable of providing insights into the function of EFs and the elongation process.
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156
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Farnung L, Vos SM, Cramer P. Structure of transcribing RNA polymerase II-nucleosome complex. Nat Commun 2018; 9:5432. [PMID: 30575770 PMCID: PMC6303367 DOI: 10.1038/s41467-018-07870-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 12/05/2018] [Indexed: 01/08/2023] Open
Abstract
Transcription of eukaryotic protein-coding genes requires passage of RNA polymerase II (Pol II) through nucleosomes, but it is unclear how this is achieved. Here we report the cryo-EM structure of transcribing Saccharomyces cerevisiae Pol II engaged with a downstream nucleosome core particle at an overall resolution of 4.4 Å. Pol II and the nucleosome are observed in a defined relative orientation that is not predicted. Pol II contacts both sides of the nucleosome dyad using its clamp head and lobe domains. Structural comparisons reveal that the elongation factors TFIIS, DSIF, NELF, SPT6, and PAF1 complex can be accommodated on the Pol II surface in the presence of the oriented nucleosome. Our results provide a starting point for analysing the mechanisms of chromatin transcription. Eukaryotic transcription requires passage of RNA polymerase II (Pol II) through chromatin, which is impaired by nucleosomes. Here the authors report the cryo-EM structure of transcribing Pol II engaged with a downstream nucleosome core particle at an overall resolution of 4.4 Å, providing insights into the mechanism of chromatin transcription.
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Affiliation(s)
- Lucas Farnung
- Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, Am Fassberg 11, 37077, Göttingen, Germany
| | - Seychelle M Vos
- Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, Am Fassberg 11, 37077, Göttingen, Germany
| | - Patrick Cramer
- Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, Am Fassberg 11, 37077, Göttingen, Germany.
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157
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Cabral JM, Oh HS, Knipe DM. ATRX promotes maintenance of herpes simplex virus heterochromatin during chromatin stress. eLife 2018; 7:40228. [PMID: 30465651 PMCID: PMC6307862 DOI: 10.7554/elife.40228] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 11/20/2018] [Indexed: 12/17/2022] Open
Abstract
The mechanisms by which mammalian cells recognize and epigenetically restrict viral DNA are not well defined. We used herpes simplex virus with bioorthogonally labeled genomes to detect host factors recruited to viral DNA shortly after its nuclear entry and found that the cellular IFI16, PML, and ATRX proteins colocalized with viral DNA by 15 min post infection. HSV-1 infection of ATRX-depleted fibroblasts resulted in elevated viral mRNA and accelerated viral DNA accumulation. Despite the early association of ATRX with vDNA, we found that initial viral heterochromatin formation is ATRX-independent. However, viral heterochromatin stability required ATRX from 4 to 8 hr post infection. Inhibition of transcription blocked viral chromatin loss in ATRX-knockout cells; thus, ATRX is uniquely required for heterochromatin maintenance during chromatin stress. These results argue that the initial formation and the subsequent maintenance of viral heterochromatin are separable mechanisms, a concept that likely extrapolates to host cell chromatin and viral latency. Cells carefully package their DNA, tightly wrapping the long, stringy molecule around spool-like groups of proteins called histones. However, the genes that are draped around histones are effectively silenced, because they are ‘hidden’ from the molecular actors that read the genetic information to create proteins. A cell can control which of its genes are active by using proteins to move histones on or off specific portions of DNA. For example, a protein known as ATRX associates with a partner to load histones onto precise DNA regions and switch them off. Wrapping DNA around histones can also be a defense mechanism against viruses, which are tiny cellular parasites that hijack the molecular machinery of a cell to create more of themselves. For instance, the herpes simplex virus, which causes cold sores and genital herpes, injects its DNA into a cell where it is used as a template to create new viral particles. By packaging the DNA of the virus around histones, the cell ensures that this foreign genetic information cannot be used to make more invaders. However, the details of this process remain unknown. In particular, it is still unclear what happens immediately after the virus penetrates the nucleus, the compartment that shelters the DNA of the cell. Here, Cabral et al. explored this question by dissecting the role of ATRX in silencing the genetic information of the herpes simplex virus. The viral DNA was labeled while inside the virus itself, and then tracked using microscopy imaging techniques as it made its way into the cell and inside the nucleus. This revealed that, almost immediately after the viral DNA had entered the nucleus, ATRX came in contact with the foreign molecule. One possibility was that ATRX would be responsible for loading certain forms of histones onto the viral DNA. However, after Cabral et al. deleted ATRX from the cell, histones were still present on the genetic information of the virus, but this association was less stable. This indicated that ATRX was only required to keep histones latched onto the viral DNA, but not to load the proteins in the first place. Overall, these results show that using histones to silence viral DNA in done in several steps: first, the foreign genetic material needs to be recognized, then histones have to be attached, and finally molecular actors should be recruited to keep histones onto the DNA. Knowing how cells ward off the herpes simplex virus could help us find ways to ‘boost’ this defense mechanism. Armed with this knowledge, we could also begin to understand why certain people are more likely to be infected by this virus.
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Affiliation(s)
- Joseph M Cabral
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, United States.,Program in Virology, Harvard Medical School, Boston, United States
| | - Hyung Suk Oh
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, United States
| | - David M Knipe
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, United States.,Program in Virology, Harvard Medical School, Boston, United States
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158
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Chang HW, Valieva ME, Safina A, Chereji RV, Wang J, Kulaeva OI, Morozov AV, Kirpichnikov MP, Feofanov AV, Gurova KV, Studitsky VM. Mechanism of FACT removal from transcribed genes by anticancer drugs curaxins. SCIENCE ADVANCES 2018; 4:eaav2131. [PMID: 30417101 PMCID: PMC6221510 DOI: 10.1126/sciadv.aav2131] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 10/10/2018] [Indexed: 05/21/2023]
Abstract
Human FACT (facilitates chromatin transcription) is a multifunctional protein complex that has histone chaperone activity and facilitates nucleosome survival and transcription through chromatin. Anticancer drugs curaxins induce FACT trapping on chromatin of cancer cells (c-trapping), but the mechanism of c-trapping is not fully understood. Here, we show that in cancer cells, FACT is highly enriched within the bodies of actively transcribed genes. Curaxin-dependent c-trapping results in redistribution of FACT from the transcribed chromatin regions to other genomic loci. Using a combination of biochemical and biophysical approaches, we have demonstrated that FACT is bound to and unfolds nucleosomes in the presence of curaxins. This tight binding to the nucleosome results in inhibition of FACT-dependent transcription in vitro in the presence of both curaxins and competitor chromatin, suggesting a mechanism of FACT trapping on bulk nucleosomes (n-trapping).
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Affiliation(s)
- Han-Wen Chang
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Maria E. Valieva
- Biology Faculty, Lomonosov Moscow State University, 119992 Moscow, Russia
- Max Planck Institute for Molecular Genetics, Ihnestraße 63-73, 14195 Berlin, Germany
| | - Alfiya Safina
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - Răzvan V. Chereji
- Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jianmin Wang
- Department of Bioinformatics, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA
| | | | - Alexandre V. Morozov
- Department of Physics and Astronomy and Center for Quantitative Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Mikhail P. Kirpichnikov
- Biology Faculty, Lomonosov Moscow State University, 119992 Moscow, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | - Alexey V. Feofanov
- Biology Faculty, Lomonosov Moscow State University, 119992 Moscow, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | - Katerina V. Gurova
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - Vasily M. Studitsky
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA
- Biology Faculty, Lomonosov Moscow State University, 119992 Moscow, Russia
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159
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Martin BJE, Chruscicki AT, Howe LJ. Transcription Promotes the Interaction of the FAcilitates Chromatin Transactions (FACT) Complex with Nucleosomes in Saccharomyces cerevisiae. Genetics 2018; 210:869-881. [PMID: 30237209 PMCID: PMC6218215 DOI: 10.1534/genetics.118.301349] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/06/2018] [Indexed: 12/20/2022] Open
Abstract
The FACT (FAcilitates Chromatin Transactions) complex is a conserved complex that maintains chromatin structure on transcriptionally active genes. Consistent with this, FACT is enriched on highly expressed genes, but how it is targeted to these regions is unknown. In vitro, FACT binds destabilized nucleosomes, supporting the hypothesis that FACT is targeted to transcribed chromatin through recognition of RNA polymerase (RNAP)-disrupted nucleosomes. In this study, we used high-resolution analysis of FACT occupancy in Saccharomyces cerevisiae to test this hypothesis. We demonstrate that FACT interacts with nucleosomes in vivo and that its interaction with chromatin is dependent on transcription by any of the three RNAPs. Deep sequencing of micrococcal nuclease-resistant fragments shows that FACT-bound nucleosomes exhibit differing nuclease sensitivity compared to bulk chromatin, consistent with a modified nucleosome structure being the preferred ligand for this complex. Interestingly, a subset of FACT-bound nucleosomes may be "overlapping dinucleosomes," in which one histone octamer invades the ∼147-bp territory normally occupied by the adjacent nucleosome. While the differing nuclease sensitivity of FACT-bound nucleosomes could also be explained by the demonstrated ability of FACT to alter nucleosome structure, transcription inhibition restores nuclease resistance, suggesting that it is not due to FACT interaction alone. Collectively, these results are consistent with a model in which FACT is targeted to transcribed genes through preferential interaction with RNAP-disrupted nucleosomes.
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Affiliation(s)
- Benjamin J E Martin
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Adam T Chruscicki
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - LeAnn J Howe
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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160
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Lorch Y, Maier-Davis B, Kornberg RD. Histone Acetylation Inhibits RSC and Stabilizes the +1 Nucleosome. Mol Cell 2018; 72:594-600.e2. [PMID: 30401433 PMCID: PMC6290470 DOI: 10.1016/j.molcel.2018.09.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 08/09/2018] [Accepted: 09/20/2018] [Indexed: 12/12/2022]
Abstract
The +1 nucleosome of yeast genes, within which reside transcription start sites, is characterized by histone acetylation, by the displacement of an H2A-H2B dimer, and by a persistent association with the RSC chromatin-remodeling complex. Here we demonstrate the interrelationship of these characteristics and the conversion of a nucleosome to the +1 state in vitro. Contrary to expectation, acetylation performs an inhibitory role, preventing the removal of a nucleosome by RSC. Inhibition is due to both enhanced RSC-histone interaction and diminished histone-chaperone interaction. Acetylation does not prevent all RSC activity, because stably bound RSC removes an H2A-H2B dimer on a timescale of seconds in an irreversible manner.
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Affiliation(s)
- Yahli Lorch
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Barbara Maier-Davis
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Roger D Kornberg
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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161
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Kozlova AL, Valieva ME, Maluchenko NV, Studitsky VM. HMGB Proteins as DNA Chaperones That Modulate Chromatin Activity. Mol Biol 2018. [DOI: 10.1134/s0026893318050096] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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162
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Abstract
Cyclin-dependent kinase 9 (CDK9) is critical for RNA Polymerase II (Pol II) transcription initiation, elongation, and termination in several key biological processes including development, differentiation, and cell fate responses. A broad range of diseases are characterized by CDK9 malfunction, illustrating its importance in maintaining transcriptional homeostasis in basal- and signal-regulated conditions. Here we provide a historical recount of CDK9 discovery and the current models suggesting CDK9 is a central hub necessary for proper execution of different steps in the transcription cycle. Finally, we discuss the current therapeutic strategies to treat CDK9 malfunction in several disease states. Abbreviations: CDK: Cyclin-dependent kinase; Pol II: RNA Polymerase II; PIC: Pre-initiation Complex; TFIIH: Transcription Factor-II H; snoRNA: small nucleolar RNA; CycT: CyclinT1/T2; P-TEFb: Positive Transcription Elongation Factor Complex; snRNP: small nuclear ribonucleo-protein; HEXIM: Hexamethylene Bis-acetamide-inducible Protein 1/2; LARP7: La-related Protein 7; MePCE: Methylphosphate Capping Enzyme; HIV: human immunodeficiency virus; TAT: trans-activator of transcription; TAR: Trans-activation response element; Hsp70: Heat Shock Protein 70; Hsp90/Cdc37: Hsp90- Hsp90 co-chaperone Cdc37; DSIF: DRB Sensitivity Inducing Factor; NELF: Negative Elongation Factor; CPSF: cleavage and polyadenylation-specific factor; CSTF: cleavage-stimulatory factor; eRNA: enhancer RNA; BRD4: Bromodomain-containing protein 4; JMJD6: Jumonji C-domain-containing protein 6; SEC: Super Elongation Complex; ELL: eleven-nineteen Lys-rich leukemia; ENL: eleven-nineteen leukemia; MLL: mixed lineage leukemia; BEC: BRD4-containing Elongation Complex; SEC-L2/L3: SEC-like complexes; KAP1: Kruppel-associated box-protein 1; KEC: KAP1-7SK Elongation Complex; DRB: Dichloro-1-ß-D-Ribofuranosylbenzimidazole; H2Bub1: H2B mono-ubiquitination; KM: KM05382; PP1: Protein Phosphatase 1; CDK9i: CDK9 inhibitor; SHAPE: Selective 2'-hydroxyl acylation analyzed by primer extension; TE: Typical enhancer; SE : Super enhancer.
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Affiliation(s)
- Curtis W Bacon
- a Biological Chemistry Graduate Program , The University of Texas Southwestern Medical Center , Dallas, TX , USA
| | - Iván D'Orso
- b Department of Microbiology , The University of Texas Southwestern Medical Center , Dallas , TX , USA
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163
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Transcription-associated histone pruning demarcates macroH2A chromatin domains. Nat Struct Mol Biol 2018; 25:958-970. [PMID: 30291361 PMCID: PMC6178985 DOI: 10.1038/s41594-018-0134-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 08/17/2018] [Indexed: 02/01/2023]
Abstract
The histone variant macroH2A occupies large repressive domains throughout the genome, however mechanisms underlying its precise deposition remain poorly understood. Here, we characterized de novo chromatin deposition of macroH2A2 using temporal genomic profiling in murine-derived fibroblasts devoid of all macroH2A isoforms. We find that macroH2A2 is first pervasively deposited genome-wide at both steady state domains and adjacent transcribed regions, the latter of which are subsequently pruned, establishing mature macroH2A2 domains. Pruning of macroH2A2 can be counteracted by chemical inhibition of transcription. Further, CRISPR/Cas9-based locus-specific transcriptional manipulation reveals that gene activation depletes pre-existing macroH2A2, while silencing triggers ectopic macroH2A2 accumulation. We demonstrate that the FACT (facilitates chromatin transcription) complex is required for macroH2A2 pruning within transcribed chromatin. Taken together, we have identified active chromatin as a boundary for macroH2A domains through a transcription-associated ‘pruning’ mechanism that establishes and maintains the faithful genomic localization of macroH2A variants.
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164
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Krajewski WA. Effects of DNA Superhelical Stress on the Stability of H2B-Ubiquitylated Nucleosomes. J Mol Biol 2018; 430:5002-5014. [PMID: 30267746 DOI: 10.1016/j.jmb.2018.09.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/27/2018] [Accepted: 09/21/2018] [Indexed: 01/31/2023]
Abstract
On the nucleosome level, histone posttranslational modifications function mainly as the regulatory signals; in addition, some posttranslational modifications can enhance nucleosome stochastic folding, which is restricted in "canonic" nucleosomes. Recently, it has been shown in vitro that symmetric or asymmetric nucleosome ubiquitylation at H2BK34 (and H2BK120, to a lesser extent) can destabilize one of the nucleosomal H2A-H2B dimers and promote nucleosome conversion to a hexasome particle [Krajewski et al. (2018). Nucleic Acids Res., 46, 7631-7642]. Such lability of H2Bub nucleosomes raises a question of whether they could accommodate transient changes in DNA torsional tensions, which are generated by virtually any process that manipulates DNA strands. Using positively or negatively supercoiled DNA minicircles and homogeneously-modified H2Bub histones, we have found that DNA topology could strongly and selectively affect nucleosome stability depending on its ubiquitylation state (here the term "nucleosome stability" means the nucleosome property to maintain its structural integrity and dynamics characteristic to "canonic" nucleosomes). The results point to a role for H2B ubiquitylation in amplifying or mitigating the effects of a DNA torque on the nucleosome stability and dynamics.
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Affiliation(s)
- Wladyslaw A Krajewski
- N.K. Koltsov Institute of Developmental Biology, Russian Academy of Sciences, Vavilova str. 26, Moscow 119334, Russia.
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165
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Nassrallah A, Rougée M, Bourbousse C, Drevensek S, Fonseca S, Iniesto E, Ait-Mohamed O, Deton-Cabanillas AF, Zabulon G, Ahmed I, Stroebel D, Masson V, Lombard B, Eeckhout D, Gevaert K, Loew D, Genovesio A, Breyton C, De Jaeger G, Bowler C, Rubio V, Barneche F. DET1-mediated degradation of a SAGA-like deubiquitination module controls H2Bub homeostasis. eLife 2018; 7:37892. [PMID: 30192741 PMCID: PMC6128693 DOI: 10.7554/elife.37892] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/22/2018] [Indexed: 12/11/2022] Open
Abstract
DE-ETIOLATED 1 (DET1) is an evolutionarily conserved component of the ubiquitination machinery that mediates the destabilization of key regulators of cell differentiation and proliferation in multicellular organisms. In this study, we provide evidence from Arabidopsis that DET1 is essential for the regulation of histone H2B monoubiquitination (H2Bub) over most genes by controlling the stability of a deubiquitination module (DUBm). In contrast with yeast and metazoan DUB modules that are associated with the large SAGA complex, the Arabidopsis DUBm only comprises three proteins (hereafter named SGF11, ENY2 and UBP22) and appears to act independently as a major H2Bub deubiquitinase activity. Our study further unveils that DET1-DDB1-Associated-1 (DDA1) protein interacts with SGF11 in vivo, linking the DET1 complex to light-dependent ubiquitin-mediated proteolytic degradation of the DUBm. Collectively, these findings uncover a signaling path controlling DUBm availability, potentially adjusting H2Bub turnover capacity to the cell transcriptional status.
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Affiliation(s)
- Amr Nassrallah
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid, Spain
| | - Martin Rougée
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France.,Université Paris-Sud, Orsay, France
| | - Clara Bourbousse
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France.,Université Paris-Sud, Orsay, France
| | - Stephanie Drevensek
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Sandra Fonseca
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid, Spain
| | - Elisa Iniesto
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid, Spain
| | - Ouardia Ait-Mohamed
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Anne-Flore Deton-Cabanillas
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Gerald Zabulon
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Ikhlak Ahmed
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - David Stroebel
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Vanessa Masson
- Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie PSL Research University, 75005 Paris, France
| | - Berangere Lombard
- Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie PSL Research University, 75005 Paris, France
| | - Dominique Eeckhout
- Department of Plant Systems Biology, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Kris Gevaert
- Department of Biochemistry, Ghent University, Ghent, Belgium.,VIB Center for Medical Biotechnology, Ghent, Belgium
| | - Damarys Loew
- Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie PSL Research University, 75005 Paris, France
| | - Auguste Genovesio
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Cecile Breyton
- Université Grenoble Alpes, Institut de Biologie Structurale, Grenoble, France
| | - Geert De Jaeger
- Department of Plant Systems Biology, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Chris Bowler
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Vicente Rubio
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid, Spain
| | - Fredy Barneche
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
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166
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Abstract
Nucleosomes compact and organize genetic material on a structural level. However, they also alter local chromatin accessibility through changes in their position, through the incorporation of histone variants, and through a vast array of histone posttranslational modifications. The dynamic nature of chromatin requires histone chaperones to process, deposit, and evict histones in different tissues and at different times in the cell cycle. This review focuses on the molecular details of canonical and variant H3-H4 histone chaperone pathways that lead to histone deposition on DNA as they are currently understood. Emphasis is placed on the most established pathways beginning with the folding, posttranslational modification, and nuclear import of newly synthesized H3-H4 histones. Next, we review the deposition of replication-coupled H3.1-H4 in S-phase and replication-independent H3.3-H4 via alternative histone chaperone pathways. Highly specialized histone chaperones overseeing the deposition of histone variants are also briefly discussed.
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Affiliation(s)
- Prerna Grover
- Genetics & Genome Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada;
| | - Jonathon S Asa
- Department of Molecular Genetics, The University of Toronto, Toronto, Ontario M5G 0A4, Canada
| | - Eric I Campos
- Genetics & Genome Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada; .,Department of Molecular Genetics, The University of Toronto, Toronto, Ontario M5G 0A4, Canada
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167
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Evrin C, Maman JD, Diamante A, Pellegrini L, Labib K. Histone H2A-H2B binding by Pol α in the eukaryotic replisome contributes to the maintenance of repressive chromatin. EMBO J 2018; 37:embj.201899021. [PMID: 30104407 PMCID: PMC6166128 DOI: 10.15252/embj.201899021] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 06/18/2018] [Accepted: 07/24/2018] [Indexed: 11/13/2022] Open
Abstract
The eukaryotic replisome disassembles parental chromatin at DNA replication forks, but then plays a poorly understood role in the re‐deposition of the displaced histone complexes onto nascent DNA. Here, we show that yeast DNA polymerase α contains a histone‐binding motif that is conserved in human Pol α and is specific for histones H2A and H2B. Mutation of this motif in budding yeast cells does not affect DNA synthesis, but instead abrogates gene silencing at telomeres and mating‐type loci. Similar phenotypes are produced not only by mutations that displace Pol α from the replisome, but also by mutation of the previously identified histone‐binding motif in the CMG helicase subunit Mcm2, the human orthologue of which was shown to bind to histones H3 and H4. We show that chromatin‐derived histone complexes can be bound simultaneously by Mcm2, Pol α and the histone chaperone FACT that is also a replisome component. These findings indicate that replisome assembly unites multiple histone‐binding activities, which jointly process parental histones to help preserve silent chromatin during the process of chromosome duplication.
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Affiliation(s)
- Cecile Evrin
- MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, UK
| | - Joseph D Maman
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Aurora Diamante
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Luca Pellegrini
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Karim Labib
- MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, UK
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168
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FACT Sets a Barrier for Cell Fate Reprogramming in Caenorhabditis elegans and Human Cells. Dev Cell 2018; 46:611-626.e12. [PMID: 30078731 PMCID: PMC6137076 DOI: 10.1016/j.devcel.2018.07.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 05/08/2018] [Accepted: 07/03/2018] [Indexed: 01/04/2023]
Abstract
The chromatin regulator FACT (facilitates chromatin transcription) is essential for ensuring stable gene expression by promoting transcription. In a genetic screen using Caenorhabditis elegans, we identified that FACT maintains cell identities and acts as a barrier for transcription factor-mediated cell fate reprogramming. Strikingly, FACT's role as a barrier to cell fate conversion is conserved in humans as we show that FACT depletion enhances reprogramming of fibroblasts. Such activity is unexpected because FACT is known as a positive regulator of gene expression, and previously described reprogramming barriers typically repress gene expression. While FACT depletion in human fibroblasts results in decreased expression of many genes, a number of FACT-occupied genes, including reprogramming-promoting factors, show increased expression upon FACT depletion, suggesting a repressive function of FACT. Our findings identify FACT as a cellular reprogramming barrier in C. elegans and humans, revealing an evolutionarily conserved mechanism for cell fate protection.
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169
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Gurova K, Chang HW, Valieva ME, Sandlesh P, Studitsky VM. Structure and function of the histone chaperone FACT - Resolving FACTual issues. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2018; 1861:S1874-9399(18)30159-7. [PMID: 30055319 PMCID: PMC6349528 DOI: 10.1016/j.bbagrm.2018.07.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/17/2018] [Accepted: 07/19/2018] [Indexed: 12/12/2022]
Abstract
FAcilitates Chromatin Transcription (FACT) has been considered essential for transcription through chromatin mostly based on cell-free experiments. However, FACT inactivation in cells does not cause a significant reduction in transcription. Moreover, not all mammalian cells require FACT for viability. Here we synthesize information from different organisms to reveal the core function(s) of FACT and propose a model that reconciles the cell-free and cell-based observations. We describe FACT structure and nucleosomal interactions, and their roles in FACT-dependent transcription, replication and repair. The variable requirements for FACT among different tumor and non-tumor cells suggest that various FACT-dependent processes have significantly different levels of relative importance in different eukaryotic cells. We propose that the stability of chromatin, which might vary among different cell types, dictates these diverse requirements for FACT to support cell viability. Since tumor cells are among the most sensitive to FACT inhibition, this vulnerability could be exploited for cancer treatment.
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Affiliation(s)
- Katerina Gurova
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA.
| | - Han-Wen Chang
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Maria E Valieva
- Biology Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Poorva Sandlesh
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA
| | - Vasily M Studitsky
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA; Biology Faculty, Lomonosov Moscow State University, Moscow, Russia.
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170
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Li M, Xu X, Chang CW, Zheng L, Shen B, Liu Y. SUMO2 conjugation of PCNA facilitates chromatin remodeling to resolve transcription-replication conflicts. Nat Commun 2018; 9:2706. [PMID: 30006506 PMCID: PMC6045570 DOI: 10.1038/s41467-018-05236-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 06/14/2018] [Indexed: 12/27/2022] Open
Abstract
During DNA synthesis, DNA replication and transcription machinery can collide, and the replication fork may temporarily dislodge RNA polymerase II (RNAPII) to resolve the transcription-replication conflict (TRC), a major source of endogenous DNA double-strand breaks (DSBs) and common fragile site (CFS) instability. However, the mechanism of TRC resolution remains unclear. Here, we show that conjugation of SUMO2, but not SUMO1 or SUMO3, to the essential replication factor PCNA is induced on transcribed chromatin by the RNAPII-bound helicase RECQ5. Proteomic analysis reveals that SUMO2-PCNA enriches histone chaperones CAF1 and FACT in the replication complex via interactions with their SUMO-interacting motifs. SUMO2-PCNA enhances CAF1-dependent histone deposition, which correlates with increased histone H3.1 at CFSs and repressive histone marks in the chromatin to reduce chromatin accessibility. Hence, SUMO2-PCNA dislodges RNAPII at CFSs, and overexpressing either SUMO2-PCNA or CAF1 reduces the incidence of DSBs in TRC-prone RECQ5-deficient cells.
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Affiliation(s)
- Min Li
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Xiaohua Xu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Chou-Wei Chang
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Li Zheng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Binghui Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Yilun Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA.
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171
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Role of RNF20 in cancer development and progression - a comprehensive review. Biosci Rep 2018; 38:BSR20171287. [PMID: 29934362 PMCID: PMC6043722 DOI: 10.1042/bsr20171287] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/20/2018] [Accepted: 06/22/2018] [Indexed: 02/06/2023] Open
Abstract
Evolving strategies to counter cancer initiation and progression rely on the identification of novel therapeutic targets that exploit the aberrant genetic changes driving oncogenesis. Several chromatin associated enzymes have been shown to influence post-translational modification (PTM) in DNA, histones, and non-histone proteins. Any deregulation of this core group of enzymes often leads to cancer development. Ubiquitylation of histone H2B in mammalian cells was identified over three decades ago. An exciting really interesting new gene (RING) family of E3 ubiquitin ligases, known as RNF20 and RNF40, monoubiquitinates histone H2A at K119 or H2B at K120, is known to function in transcriptional elongation, DNA double-strand break (DSB) repair processes, maintenance of chromatin differentiation, and exerting tumor suppressor activity. RNF20 is somatically altered in breast, lung, prostate cancer, clear cell renal cell carcinoma (ccRCC), and mixed lineage leukemia, and its reduced expression is a key factor in initiating genome instability; and it also functions as one of the significant driving factors of oncogenesis. Loss of RNF20/40 and H2B monoubiquitination (H2Bub1) is found in several cancers and is linked to an aggressive phenotype, and is also an indicator of poor prognosis. In this review, we summarized the current knowledge of RNF20 in chronic inflammation-driven cancers, DNA DSBs, and apoptosis, and its impact on chromatin structure beyond the single nucleosome level.
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172
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Wang T, Liu Y, Edwards G, Krzizike D, Scherman H, Luger K. The histone chaperone FACT modulates nucleosome structure by tethering its components. Life Sci Alliance 2018; 1:e201800107. [PMID: 30456370 PMCID: PMC6238592 DOI: 10.26508/lsa.201800107] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 06/29/2018] [Accepted: 06/29/2018] [Indexed: 11/24/2022] Open
Abstract
The histone chaperone FACT functions by tethering partial components of the nucleosome, thereby assisting nucleosome disassembly and reassembly during transcription. Human FAcilitates Chromatin Transcription (hFACT) is a conserved histone chaperone that was originally described as a transcription elongation factor with potential nucleosome assembly functions. Here, we show that FACT has moderate tetrasome assembly activity but facilitates H2A–H2B deposition to form hexasomes and nucleosomes. In the process, FACT tethers components of the nucleosome through interactions with H2A–H2B, resulting in a defined intermediate complex comprising FACT, a histone hexamer, and DNA. Free DNA extending from the tetrasome then competes FACT off H2A–H2B, thereby promoting hexasome and nucleosome formation. Our studies provide mechanistic insight into how FACT may stabilize partial nucleosome structures during transcription or nucleosome assembly, seemingly facilitating both nucleosome disassembly and nucleosome assembly.
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Affiliation(s)
- Tao Wang
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Yang Liu
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Garrett Edwards
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Daniel Krzizike
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Hataichanok Scherman
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.,Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA
| | - Karolin Luger
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
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173
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Chen P, Dong L, Hu M, Wang YZ, Xiao X, Zhao Z, Yan J, Wang PY, Reinberg D, Li M, Li W, Li G. Functions of FACT in Breaking the Nucleosome and Maintaining Its Integrity at the Single-Nucleosome Level. Mol Cell 2018; 71:284-293.e4. [DOI: 10.1016/j.molcel.2018.06.020] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 05/01/2018] [Accepted: 06/13/2018] [Indexed: 12/12/2022]
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174
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Pfab A, Grønlund JT, Holzinger P, Längst G, Grasser KD. The Arabidopsis Histone Chaperone FACT: Role of the HMG-Box Domain of SSRP1. J Mol Biol 2018; 430:2747-2759. [PMID: 29966609 DOI: 10.1016/j.jmb.2018.06.046] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 06/18/2018] [Accepted: 06/22/2018] [Indexed: 11/15/2022]
Abstract
Histone chaperones play critical roles in regulated structural transitions of chromatin in eukaryotic cells that involve nucleosome disassembly and reassembly. The histone chaperone FACT is a heterodimeric complex consisting in plants and metazoa of SSRP1/SPT16 and is involved in dynamic nucleosome reorganization during various DNA-dependent processes including transcription, replication and repair. The C-terminal HMG-box domain of the SSRP1 subunit mediates interactions with DNA and nucleosomes in vitro, but its relevance in vivo is unclear. Here, we demonstrate that Arabidopsis ssrp1-2 mutant plants express a C-terminally truncated SSRP1 protein. Although the structure of the truncated HMG-box domain is distinctly disturbed, it still exhibits residual DNA-binding activity, but has lost DNA-bending activity. Since ssrp1-2 plants are phenotypically affected but viable, the HMG-box domain may be functionally non-essential. To examine this possibility, SSRP1∆HMG completely lacking the HMG-box domain was studied. SSRP1∆HMG in vitro did not bind to DNA and its interactions with nucleosomes were severely reduced. Nevertheless, the protein showed a nuclear mobility and protein interactions similar to SSRP1. Interestingly, expression of SSRP1∆HMG is almost as efficient as that of full-length SSRP1 in supporting normal growth and development of the otherwise non-viable Arabidopsis ssrp1-1 mutant. SSRP1∆HMG is structurally similar to the fungal ortholog termed Pob3 that shares clear similarity with SSRP1, but it lacks the C-terminal HMG-box. Therefore, our findings indicate that the HMG-box domain conserved among SSRP1 proteins is not critical in Arabidopsis, and thus, the functionality of SSRP1/SPT16 in plants/metazoa and Pob3/Spt16 in fungi is perhaps more similar than anticipated.
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Affiliation(s)
- Alexander Pfab
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Jesper T Grønlund
- Department of Life Sciences, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark
| | - Philipp Holzinger
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Gernot Längst
- Department of Biochemistry III, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Klaus D Grasser
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany.
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175
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Marcianò G, Da Vela S, Tria G, Svergun DI, Byron O, Huang DT. Structure-specific recognition protein-1 (SSRP1) is an elongated homodimer that binds histones. J Biol Chem 2018; 293:10071-10083. [PMID: 29764934 PMCID: PMC6028955 DOI: 10.1074/jbc.ra117.000994] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 05/14/2018] [Indexed: 12/31/2022] Open
Abstract
The histone chaperone complex facilitates chromatin transcription (FACT) plays important roles in DNA repair, replication, and transcription. In the formation of this complex, structure-specific recognition protein-1 (SSRP1) heterodimerizes with suppressor of Ty 16 (SPT16). SSRP1 also has SPT16-independent functions, but how SSRP1 functions alone remains elusive. Here, using analytical ultracentrifugation (AUC) and small-angle X-ray scattering (SAXS) techniques, we characterized human SSRP1 and that from the amoeba Dictyostelium discoideum and show that both orthologs form an elongated homodimer in solution. We found that substitutions in the SSRP1 pleckstrin homology domain known to bind SPT16 also disrupt SSRP1 homodimerization. Moreover, AUC and SAXS analyses revealed that SSRP1 homodimerization and heterodimerization with SPT16 (resulting in FACT) involve the same SSRP1 surface, namely the PH2 region, and that the FACT complex contains only one molecule of SSRP1. These observations suggest that SSRP1 homo- and heterodimerization might be mutually exclusive. Moreover, isothermal titration calorimetry analyses disclosed that SSRP1 binds both histones H2A-H2B and H3-H4 and that disruption of SSRP1 homodimerization decreases its histone-binding affinity. Together, our results provide evidence for regulation of SSRP1 by homodimerization and suggest a potential role for homodimerization in facilitating SPT16-independent functions of SSRP1.
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Affiliation(s)
- Gabriele Marcianò
- From the Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, and the Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1BD, Scotland, United Kingdom,
| | - Stefano Da Vela
- the European Molecular Biology Laboratory, Hamburg Outstation, EMBL ℅ DESY, Notkestrasse 85, 22607 Hamburg, Germany, and
| | - Giancarlo Tria
- the European Molecular Biology Laboratory, Hamburg Outstation, EMBL ℅ DESY, Notkestrasse 85, 22607 Hamburg, Germany, and
| | - Dmitri I Svergun
- the European Molecular Biology Laboratory, Hamburg Outstation, EMBL ℅ DESY, Notkestrasse 85, 22607 Hamburg, Germany, and
| | - Olwyn Byron
- the School of Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Danny T Huang
- From the Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, and the Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1BD, Scotland, United Kingdom,
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176
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H3K4 Methylation Dependent and Independent Chromatin Regulation by JHD2 and SET1 in Budding Yeast. G3-GENES GENOMES GENETICS 2018; 8:1829-1839. [PMID: 29599176 PMCID: PMC5940172 DOI: 10.1534/g3.118.200151] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Set1 and Jhd2 regulate the methylation state of histone H3 lysine-4 (H3K4me) through their opposing methyltransferase and demethylase activities in the budding yeast Saccharomyces cerevisiae. H3K4me associates with actively transcribed genes and, like both SET1 and JHD2 themselves, is known to regulate gene expression diversely. It remains unclear, however, if Set1 and Jhd2 act solely through H3K4me. Relevantly, Set1 methylates lysine residues in the kinetochore protein Dam1 while genetic studies of the S. pombe SET1 ortholog suggest the existence of non-H3K4 Set1 targets relevant to gene regulation. We interrogated genetic interactions of JHD2 and SET1 with essential genes involved in varied aspects of the transcription cycle. Our findings implicate JHD2 in genetic inhibition of the histone chaperone complexes Spt16-Pob3 (FACT) and Spt6-Spn1. This targeted screen also revealed that JHD2 inhibits the Nrd1-Nab3-Sen1 (NNS) transcription termination complex. We find that while Jhd2’s impact on these transcription regulatory complexes likely acts via H3K4me, Set1 governs the roles of FACT and NNS through opposing H3K4-dependent and -independent functions. We also identify diametrically opposing consequences for mutation of H3K4 to alanine or arginine, illuminating that caution must be taken in interpreting histone mutation studies. Unlike FACT and NNS, detailed genetic studies suggest an H3K4me-centric mode of Spt6-Spn1 regulation by JHD2 and SET1. Chromatin immunoprecipitation and transcript quantification experiments show that Jhd2 opposes the positioning of a Spt6-deposited nucleosome near the transcription start site of SER3, a Spt6-Spn1 regulated gene, leading to hyper-induction of SER3. In addition to confirming and extending an emerging role for Jhd2 in the control of nucleosome occupancy near transcription start sites, our findings suggest some of the chromatin regulatory functions of Set1 are independent of H3K4 methylation.
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177
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FACT complex is required for DNA demethylation at heterochromatin during reproduction in Arabidopsis. Proc Natl Acad Sci U S A 2018; 115:E4720-E4729. [PMID: 29712855 PMCID: PMC5960277 DOI: 10.1073/pnas.1713333115] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The DEMETER (DME) DNA glycosylase catalyzes genome-wide DNA demethylation and is required for endosperm genomic imprinting and embryo viability. Targets of DME-mediated DNA demethylation reside in small, euchromatic, AT-rich transposons and at the boundaries of large transposons, but how DME interacts with these diverse chromatin states is unknown. The STRUCTURE SPECIFIC RECOGNITION PROTEIN 1 (SSRP1) subunit of the chromatin remodeler FACT (facilitates chromatin transactions), was previously shown to be involved in the DME-dependent regulation of genomic imprinting in Arabidopsis endosperm. Therefore, to investigate the interaction between DME and chromatin, we focused on the activity of the two FACT subunits, SSRP1 and SUPPRESSOR of TY16 (SPT16), during reproduction in Arabidopsis We found that FACT colocalizes with nuclear DME in vivo, and that DME has two classes of target sites, the first being euchromatic and accessible to DME, but the second, representing over half of DME targets, requiring the action of FACT for DME-mediated DNA demethylation genome-wide. Our results show that the FACT-dependent DME targets are GC-rich heterochromatin domains with high nucleosome occupancy enriched with H3K9me2 and H3K27me1. Further, we demonstrate that heterochromatin-associated linker histone H1 specifically mediates the requirement for FACT at a subset of DME-target loci. Overall, our results demonstrate that FACT is required for DME targeting by facilitating its access to heterochromatin.
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178
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Acetylation-Dependent Recruitment of the FACT Complex and Its Role in Regulating Pol II Occupancy Genome-Wide in Saccharomyces cerevisiae. Genetics 2018; 209:743-756. [PMID: 29695490 DOI: 10.1534/genetics.118.300943] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 04/23/2018] [Indexed: 12/23/2022] Open
Abstract
Histone chaperones, chromatin remodelers, and histone modifying complexes play a critical role in alleviating the nucleosomal barrier for DNA-dependent processes. Here, we have examined the role of two highly conserved yeast (Saccharomyces cerevisiae) histone chaperones, facilitates chromatin transcription (FACT) and Spt6, in regulating transcription. We show that the H3 tail contributes to the recruitment of FACT to coding sequences in a manner dependent on acetylation. We found that deleting a H3 histone acetyltransferase Gcn5 or mutating lysines on the H3 tail impairs FACT recruitment at ADH1 and ARG1 genes. However, deleting the H4 tail or mutating the H4 lysines failed to dampen FACT occupancy in coding regions. Additionally, we show that FACT depletion reduces RNA polymerase II (Pol II) occupancy genome-wide. Spt6 depletion leads to a reduction in Pol II occupancy toward the 3'-end, in a manner dependent on the gene length. Severe transcription and histone-eviction defects were also observed in a strain that was impaired for Spt6 recruitment (spt6Δ202) and depleted of FACT. Importantly, the severity of the defect strongly correlated with wild-type Pol II occupancies at these genes, indicating critical roles for Spt6 and Spt16 in promoting high-level transcription. Collectively, our results show that both FACT and Spt6 are important for transcription globally and may participate during different stages of transcription.
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179
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Lin D, Hiron TK, O'Callaghan CA. Intragenic transcriptional interference regulates the human immune ligand MICA. EMBO J 2018; 37:embj.201797138. [PMID: 29643123 DOI: 10.15252/embj.201797138] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 02/08/2018] [Accepted: 02/09/2018] [Indexed: 12/27/2022] Open
Abstract
Many human genes have tandem promoters driving overlapping transcription, but the value of this distributed promoter configuration is generally unclear. Here we show that MICA, a gene encoding a ligand for the activating immune receptor NKG2D, contains a conserved upstream promoter that expresses a noncoding transcript. Transcription from the upstream promoter represses the downstream standard promoter activity in cis through transcriptional interference. The effect of transcriptional interference depends on the strength of transcription from the upstream promoter and can be described quantitatively by a simple reciprocal repressor function. Transcriptional interference coincides with recruitment at the standard downstream promoter of the FACT histone chaperone complex, which is involved in nucleosomal remodelling during transcription. The mechanism is invoked in the regulation of MICA expression by the physiological inputs interferon-γ and interleukin-4 that act on the upstream promoter. Genome-wide analysis indicates that transcriptional interference between tandem intragenic promoters may constitute a general mechanism with widespread importance in human transcriptional regulation.
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Affiliation(s)
- Da Lin
- Nuffield Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Thomas K Hiron
- Nuffield Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Christopher A O'Callaghan
- Nuffield Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
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180
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Abstract
The nucleosome serves as a general gene repressor, preventing all initiation of transcription except that which is brought about by specific positive regulatory mechanisms. The positive mechanisms begin with chromatin-remodeling by complexes that slide, disrupt, or otherwise alter the structure and organization of nucleosomes. RSC in yeast and its counterpart PBAF in human cells are the major remodeling complexes for transcription. RSC creates a nucleosome-free region in front of a gene, flanked by strongly positioned +1 and -1 nucleosomes, with the transcription start site typically 10-15 bp inside the border of the +1 nucleosome. RSC also binds stably to nucleosomes harboring regulatory elements and to +1 nucleosomes, perturbing their structures in a manner that partially exposes their DNA sequences. The cryo-electron microscope structure of a RSC-nucleosome complex reveals such a structural perturbation, with the DNA largely unwrapped from the nucleosome and likely interacting with a positively charged surface of RSC. Such unwrapping both exposes the DNA and enables its translocation across the histone octamer of the nucleosome by an ATP-dependent activity of RSC. Genetic studies have revealed additional roles of RSC in DNA repair, chromosome segregation, and other chromosomal DNA transactions. These functions of RSC likely involve the same fundamental activities, DNA unwrapping and DNA translocation.
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181
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Bobkov GOM, Gilbert N, Heun P. Centromere transcription allows CENP-A to transit from chromatin association to stable incorporation. J Cell Biol 2018; 217:1957-1972. [PMID: 29626011 PMCID: PMC5987708 DOI: 10.1083/jcb.201611087] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 07/11/2017] [Accepted: 03/14/2018] [Indexed: 12/11/2022] Open
Abstract
How transcription contributes to the loading of the centromere histone CENP-A is unclear. Bobkov et al. report that transcription-mediated chromatin remodeling enables the transition of centromeric CENP-A from chromatin association to full nucleosome incorporation. Centromeres are essential for chromosome segregation and are specified epigenetically by the presence of the histone H3 variant CENP-A. In flies and humans, replenishment of the centromeric mark is uncoupled from DNA replication and requires the removal of H3 “placeholder” nucleosomes. Although transcription at centromeres has been previously linked to the loading of new CENP-A, the underlying molecular mechanism remains poorly understood. Here, we used Drosophila melanogaster tissue culture cells to show that centromeric presence of actively transcribing RNA polymerase II temporally coincides with de novo deposition of dCENP-A. Using a newly developed dCENP-A loading system that is independent of acute transcription, we found that short inhibition of transcription impaired dCENP-A incorporation into chromatin. Interestingly, initial targeting of dCENP-A to centromeres was unaffected, revealing two stability states of newly loaded dCENP-A: a salt-sensitive association with the centromere and a salt-resistant chromatin-incorporated form. This suggests that transcription-mediated chromatin remodeling is required for the transition of dCENP-A to fully incorporated nucleosomes at the centromere.
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Affiliation(s)
- Georg O M Bobkov
- Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, Scotland, UK.,Faculty of Biology, Albert Ludwigs Universität Freiburg, Freiburg, Germany
| | - Nick Gilbert
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, Scotland, UK
| | - Patrick Heun
- Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, Scotland, UK
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182
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Liu Y, Liu S, Yuan S, Yu H, Zhang Y, Yang X, Xie G, Chen Z, Li W, Xu B, Sun L, Shang Y, Liang J. Chromodomain protein CDYL is required for transmission/restoration of repressive histone marks. J Mol Cell Biol 2018; 9:178-194. [PMID: 28402439 DOI: 10.1093/jmcb/mjx013] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 04/02/2017] [Indexed: 12/22/2022] Open
Abstract
Faithful transmission or restoration of epigenetic information such as repressive histone modifications through generations is critical for the maintenance of cell identity. We report here that chromodomain Y-like protein (CDYL), a chromodomain-containing transcription corepressor, is physically associated with chromatin assembly factor 1 (CAF-1) and the replicative helicase MCM complex. We showed that CDYL bridges CAF-1 and MCM, facilitating histone transfer and deposition during DNA replication. We demonstrated that CDYL recruits histone-modifying enzymes G9a, SETDB1, and EZH2 to replication forks, leading to the addition of H3K9me2/3 and H3K27me2/3 on newly deposited histone H3. Significantly, depletion of CDYL impedes early S phase progression and sensitizes cells to DNA damage. Our data indicate that CDYL plays an important role in the transmission/restoration of repressive histone marks, thereby preserving the epigenetic landscape for the maintenance of cell identity.
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Affiliation(s)
- Yongqing Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Shumeng Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Shuai Yuan
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Huajing Yu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yu Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Xiaohan Yang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Guojia Xie
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Zhe Chen
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Wanjin Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Bosen Xu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Luyang Sun
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yongfeng Shang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China.,Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Jing Liang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
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183
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McCullough LL, Connell Z, Xin H, Studitsky VM, Feofanov AV, Valieva ME, Formosa T. Functional roles of the DNA-binding HMGB domain in the histone chaperone FACT in nucleosome reorganization. J Biol Chem 2018. [PMID: 29514976 DOI: 10.1074/jbc.ra117.000199] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The essential histone chaperone FACT (facilitates chromatin transcription) promotes both nucleosome assembly and disassembly. FACT is a heterodimer of Spt16 with either SSRP1 or Pob3, differing primarily by the presence of a high-mobility group B (HMGB) DNA-binding domain furnished only by SSRP1. Yeast FACT lacks the intrinsic HMGB domain found in SSRP1-based homologs such as human FACT, but yeast FACT activity is supported by Nhp6, which is a freestanding, single HMGB-domain protein. The importance of histone binding by FACT domains has been established, but the roles of DNA-binding activity remain poorly understood. Here, we examined these roles by fusing single or multiple HMGB modules to Pob3 to mimic SSRP1 or to test the effects of extended DNA-binding capacity. Human FACT and a yeast mimic both required Nhp6 to support nucleosome reorganization in vitro, indicating that a single intrinsic DNA-binding HMGB module is insufficient for full FACT activity. Three fused HMGB modules supported activity without Nhp6 assistance, but this FACT variant did not efficiently release from nucleosomes and was toxic in vivo Notably, intrinsic DNA-binding HMGB modules reduced the DNA accessibility and histone H2A-H2B dimer loss normally associated with nucleosome reorganization. We propose that DNA bending by HMGB domains promotes nucleosome destabilization and reorganization by exposing FACT's histone-binding sites, but DNA bending also produces DNA curvature needed to accommodate nucleosome assembly. Intrinsic DNA-bending activity therefore favors nucleosome assembly by FACT over nucleosome reorganization, but excessive activity impairs FACT release, suggesting a quality control checkpoint during nucleosome assembly.
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Affiliation(s)
- Laura L McCullough
- From the Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Zaily Connell
- From the Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Hua Xin
- From the Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Vasily M Studitsky
- the Biology Faculty, Lomonosov, Moscow State University, Leninskie Gory 1, Moscow 119992, Russia.,the Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111
| | - Alexey V Feofanov
- the Biology Faculty, Lomonosov, Moscow State University, Leninskie Gory 1, Moscow 119992, Russia.,the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia, and
| | - Maria E Valieva
- the Biology Faculty, Lomonosov, Moscow State University, Leninskie Gory 1, Moscow 119992, Russia
| | - Tim Formosa
- From the Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah 84132,
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184
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Fitz J, Neumann T, Pavri R. Regulation of RNA polymerase II processivity by Spt5 is restricted to a narrow window during elongation. EMBO J 2018. [PMID: 29514850 PMCID: PMC5897773 DOI: 10.15252/embj.201797965] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Spt5 is a highly conserved RNA polymerase II (Pol II)‐associated pausing and elongation factor. However, its impact on global elongation and Pol II processivity in mammalian cells has not been clarified. Here, we show that depleting Spt5 in mouse embryonic fibroblasts (MEFs) does not cause global elongation defects or decreased elongation rates. Instead, in Spt5‐depleted cells, a fraction of Pol II molecules are dislodged during elongation, thus decreasing the number of Pol II complexes that complete the transcription cycle. Most strikingly, this decrease is restricted to a narrow window between 15 and 20 kb from the promoter, a distance which coincides with the stage where accelerating Pol II attains maximum elongation speed. Consequently, long genes show a greater dependency on Spt5 for optimal elongation efficiency and overall gene expression than short genes. We propose that an important role of Spt5 in mammalian elongation is to promote the processivity of those Pol II complexes that are transitioning toward maximum elongation speed 15–20 kb from the promoter.
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Affiliation(s)
- Johanna Fitz
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Tobias Neumann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
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185
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Pfab A, Breindl M, Grasser KD. The Arabidopsis histone chaperone FACT is required for stress-induced expression of anthocyanin biosynthetic genes. PLANT MOLECULAR BIOLOGY 2018; 96:367-374. [PMID: 29332189 DOI: 10.1007/s11103-018-0701-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/10/2018] [Indexed: 05/06/2023]
Abstract
The histone chaperone FACT is involved in the expression of genes encoding anthocyanin biosynthetic enzymes also upon induction by moderate high-light and therefore contributes to the stress-induced plant pigmentation. The histone chaperone FACT consists of the SSRP1 and SPT16 proteins and associates with transcribing RNAPII (RNAPII) along the transcribed region of genes. FACT can promote transcriptional elongation by destabilising nucleosomes in the path of RNA polymerase II, thereby facilitating efficient transcription of chromatin templates. Transcript profiling of Arabidopsis plants depleted in SSRP1 or SPT16 demonstrates that only a small subset of genes is differentially expressed relative to wild type. The majority of these genes is either up- or down-regulated in both the ssrp1 and spt16 plants. Among the down-regulated genes, those encoding enzymes of the biosynthetic pathway of the plant secondary metabolites termed anthocyanins (but not regulators of the pathway) are overrepresented. Upon exposure to moderate high-light stress several of these genes are up-regulated to a lesser extent in ssrp1/spt16 compared to wild type plants, and accordingly the mutant plants accumulate lower amounts of anthocyanin pigments. Moreover, the expression of SSRP1 and SPT16 is induced under these conditions. Therefore, our findings indicate that FACT is a novel factor required for the accumulation of anthocyanins in response to light-induction.
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Affiliation(s)
- Alexander Pfab
- Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Matthias Breindl
- Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Klaus D Grasser
- Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
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186
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Shanmugam MK, Arfuso F, Arumugam S, Chinnathambi A, Jinsong B, Warrier S, Wang LZ, Kumar AP, Ahn KS, Sethi G, Lakshmanan M. Role of novel histone modifications in cancer. Oncotarget 2018; 9:11414-11426. [PMID: 29541423 PMCID: PMC5834259 DOI: 10.18632/oncotarget.23356] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/01/2017] [Indexed: 01/02/2023] Open
Abstract
Oncogenesis is a multistep process mediated by a variety of factors including epigenetic modifications. Global epigenetic post-translational modifications have been detected in almost all cancers types. Epigenetic changes appear briefly and do not involve permanent changes to the primary DNA sequence. These epigenetic modifications occur in key oncogenes, tumor suppressor genes, and transcription factors, leading to cancer initiation and progression. The most commonly observed epigenetic changes include DNA methylation, histone lysine methylation and demethylation, histone lysine acetylation and deacetylation. However, there are several other novel post-translational modifications that have been observed in recent times such as neddylation, sumoylation, glycosylation, phosphorylation, poly-ADP ribosylation, ubiquitination as well as transcriptional regulation and these have been briefly discussed in this article. We have also highlighted the diverse epigenetic changes that occur during the process of tumorigenesis and described the role of histone modifications that can occur on tumor suppressor genes as well as oncogenes, which regulate tumorigenesis and can thus form the basis of novel strategies for cancer therapy.
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Affiliation(s)
- Muthu K. Shanmugam
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Frank Arfuso
- Stem Cell and Cancer Biology Laboratory, School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia
| | - Surendar Arumugam
- Institute of Molecular and Cell Biology, A*STAR, Biopolis Drive, Proteos, Singapore, Singapore
| | - Arunachalam Chinnathambi
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Bian Jinsong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Sudha Warrier
- Division of Cancer Stem Cells and Cardiovascular Regeneration, School of Regenerative Medicine, Manipal Academy of Higher Education (MAHE), Bangalore, India
| | - Ling Zhi Wang
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Alan Prem Kumar
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
- National University Cancer Institute, National University Health System, Singapore, Singapore
- Department of Biological Sciences, University of North Texas, Denton, Texas, USA
| | - Kwang Seok Ahn
- College of Korean Medicine, Kyung Hee University, Dongdaemun-gu, Seoul, Korea
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Manikandan Lakshmanan
- Institute of Molecular and Cell Biology, A*STAR, Biopolis Drive, Proteos, Singapore, Singapore
- Department of Pathology, National University Hospital Singapore, Singapore, Singapore
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187
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Leonova K, Safina A, Nesher E, Sandlesh P, Pratt R, Burkhart C, Lipchick B, Gitlin I, Frangou C, Koman I, Wang J, Kirsanov K, Yakubovskaya MG, Gudkov AV, Gurova K. TRAIN (Transcription of Repeats Activates INterferon) in response to chromatin destabilization induced by small molecules in mammalian cells. eLife 2018; 7:e30842. [PMID: 29400649 PMCID: PMC5815852 DOI: 10.7554/elife.30842] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 02/04/2018] [Indexed: 12/13/2022] Open
Abstract
Cellular responses to the loss of genomic stability are well-established, while how mammalian cells respond to chromatin destabilization is largely unknown. We previously found that DNA demethylation on p53-deficient background leads to transcription of repetitive heterochromatin elements, followed by an interferon response, a phenomenon we named TRAIN (Transcription of Repeats Activates INterferon). Here, we report that curaxin, an anticancer small molecule, destabilizing nucleosomes via disruption of histone/DNA interactions, also induces TRAIN. Furthermore, curaxin inhibits oncogene-induced transformation and tumor growth in mice in an interferon-dependent manner, suggesting that anticancer activity of curaxin, previously attributed to p53-activation and NF-kappaB-inhibition, may also involve induction of interferon response to epigenetic derepression of the cellular 'repeatome'. Moreover, we observed that another type of drugs decondensing chromatin, HDAC inhibitor, also induces TRAIN. Thus, we proposed that TRAIN may be one of the mechanisms ensuring epigenetic integrity of mammalian cells via elimination of cells with desilenced chromatin.
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Affiliation(s)
- Katerina Leonova
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
| | - Alfiya Safina
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
| | - Elimelech Nesher
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
- Department of Molecular BiologyAriel UniversityArielIsrael
| | - Poorva Sandlesh
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
| | - Rachel Pratt
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
| | | | - Brittany Lipchick
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
| | - Ilya Gitlin
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
| | - Costakis Frangou
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
| | - Igor Koman
- Department of Molecular BiologyAriel UniversityArielIsrael
| | - Jianmin Wang
- Department of BioinformaticsRoswell Park Cancer InstituteBuffaloUnited States
| | - Kirill Kirsanov
- Department of Chemical CarcinogenesisInstitute of Carcinogenesis, Blokhin Cancer Research Center RAMSMoscowRussia
| | - Marianna G Yakubovskaya
- Department of Chemical CarcinogenesisInstitute of Carcinogenesis, Blokhin Cancer Research Center RAMSMoscowRussia
| | - Andrei V Gudkov
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
| | - Katerina Gurova
- Department of Cell Stress BiologyRoswell Park Cancer InstituteBuffaloUnited States
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188
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Zhao PA, Rivera-Mulia JC, Gilbert DM. Replication Domains: Genome Compartmentalization into Functional Replication Units. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1042:229-257. [DOI: 10.1007/978-981-10-6955-0_11] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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189
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Li J, Duns G, Westers H, Sijmons R, van den Berg A, Kok K. SETD2: an epigenetic modifier with tumor suppressor functionality. Oncotarget 2018; 7:50719-50734. [PMID: 27191891 PMCID: PMC5226616 DOI: 10.18632/oncotarget.9368] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/05/2016] [Indexed: 11/25/2022] Open
Abstract
In the past decade important progress has been made in our understanding of the epigenetic regulatory machinery. It has become clear that genetic aberrations in multiple epigenetic modifier proteins are associated with various types of cancer. Moreover, targeting the epigenome has emerged as a novel tool to treat cancer patients. Recently, the first drugs have been reported that specifically target SETD2-negative tumors. In this review we discuss the studies on the associated protein, Set domain containing 2 (SETD2), a histone modifier for which mutations have only recently been associated with cancer development. Our review starts with the structural characteristics of SETD2 and extends to its corresponding function by combining studies on SETD2 function in yeast, Drosophila, Caenorhabditis elegans, mice, and humans. SETD2 is now generally known as the single human gene responsible for trimethylation of lysine 36 of Histone H3 (H3K36). H3K36me3 readers that recruit protein complexes to carry out specific processes, including transcription elongation, RNA processing, and DNA repair, determine the impact of this histone modification. Finally, we describe the prevalence of SETD2-inactivating mutations in cancer, with the highest frequency in clear cell Renal Cell Cancer, and explore how SETD2-inactivation might contribute to tumor development.
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Affiliation(s)
- Jun Li
- Department of Genetics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Gerben Duns
- Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, Canada
| | - Helga Westers
- Department of Genetics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Rolf Sijmons
- Department of Genetics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Anke van den Berg
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Klaas Kok
- Department of Genetics, University of Groningen, University Medical Center Groningen, The Netherlands
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190
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Serra-Cardona A, Zhang Z. Replication-Coupled Nucleosome Assembly in the Passage of Epigenetic Information and Cell Identity. Trends Biochem Sci 2017; 43:136-148. [PMID: 29292063 DOI: 10.1016/j.tibs.2017.12.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/07/2017] [Accepted: 12/09/2017] [Indexed: 12/31/2022]
Abstract
During S phase, replicated DNA must be assembled into nucleosomes using both newly synthesized and parental histones in a process that is tightly coupled to DNA replication. This DNA replication-coupled process is regulated by multitude of histone chaperones as well as by histone-modifying enzymes. In recent years novel insights into nucleosome assembly of new H3-H4 tetramers have been gained through studies on the classical histone chaperone CAF-1 and the identification of novel factors involved in this process. Moreover, in vitro reconstitution of chromatin replication has shed light on nucleosome assembly of parental H3-H4, a process that remains elusive. Finally, recent studies have revealed that the replication-coupled nucleosome assembly is important for the determination and maintenance of cell fate in multicellular organisms.
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Affiliation(s)
- Albert Serra-Cardona
- Institute for Cancer Genetics, Columbia University, New York, NY 10032, USA; Department of Pediatrics, Columbia University, New York, NY 10032, USA; Department of Genetics and Development, Columbia University, New York, NY 10032, USA
| | - Zhiguo Zhang
- Institute for Cancer Genetics, Columbia University, New York, NY 10032, USA; Department of Pediatrics, Columbia University, New York, NY 10032, USA; Department of Genetics and Development, Columbia University, New York, NY 10032, USA.
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191
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Nyamugenda E, Cox AB, Pierce JB, Banning RC, Huynh ML, May C, Marshall S, Turkal CE, Duina AA. Charged residues on the side of the nucleosome contribute to normal Spt16-gene interactions in budding yeast. Epigenetics 2017; 13:1-7. [PMID: 29271283 DOI: 10.1080/15592294.2017.1418132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Previous work in Saccharomyces cerevisiae identified three residues located in close proximity to each other on the side of the nucleosome whose integrity is required for proper association of the Spt16 component of the FACT complex across transcribed genes. In an effort to gain further insights into the parameters that control Spt16 interactions with genes in vivo, we tested the effects of additional histone mutants on Spt16 occupancy across two constitutively transcribed genes. These studies revealed that mutations in several charged residues in the vicinity of the three residues originally identified as important for Spt16-gene interactions also significantly perturb normal association of Spt16 across genes. Based on these and our previous findings, we propose that the charge landscape across the region encompassed by these residues, which we refer to as the Influences Spt16-Gene Interactions or ISGI region, is an important contributor to proper Spt16-gene interactions in vivo.
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Affiliation(s)
| | - A Brandon Cox
- a Biology Department , Hendrix College , Conway , AR 72032
| | - Jacob B Pierce
- a Biology Department , Hendrix College , Conway , AR 72032
| | - Ryan C Banning
- a Biology Department , Hendrix College , Conway , AR 72032
| | | | - Catey May
- a Biology Department , Hendrix College , Conway , AR 72032
| | - Sarah Marshall
- a Biology Department , Hendrix College , Conway , AR 72032
| | | | - Andrea A Duina
- a Biology Department , Hendrix College , Conway , AR 72032
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192
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Crickard JB, Lee J, Lee TH, Reese JC. The elongation factor Spt4/5 regulates RNA polymerase II transcription through the nucleosome. Nucleic Acids Res 2017; 45:6362-6374. [PMID: 28379497 PMCID: PMC5499766 DOI: 10.1093/nar/gkx220] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 03/23/2017] [Indexed: 01/04/2023] Open
Abstract
RNA polymerase II (RNAPII) passes through the nucleosome in a coordinated manner, generating several intermediate nucleosomal states as it breaks and then reforms histone–DNA contacts ahead of and behind it, respectively. Several studies have defined transcription-induced nucleosome intermediates using only RNA Polymerase. However, RNAPII is decorated with elongation factors as it transcribes the genome. One such factor, Spt4/5, becomes an integral component of the elongation complex, making direct contact with the ‘jaws’ of RNAPII and nucleic acids in the transcription scaffold. We have characterized the effect of incorporating Spt4/5 into the elongation complex on transcription through the 601R nucleosome. Spt4/5 suppressed RNAPII pausing at the major H3/H4-induced arrest point, resulting in downstream re-positioning of RNAPII further into the nucleosome. Using a novel single molecule FRET system, we found that Spt4/5 affected the kinetics of DNA re-wrapping and stabilized a nucleosomal intermediate with partially unwrapped DNA behind RNAPII. Comparison of nucleosomes of different sequence polarities suggest that the strength of the DNA–histone interactions behind RNAPII specifies the Spt4/5 requirement. We propose that Spt4/5 may be important to coordinate the mechanical movement of RNAPII through the nucleosome with co-transcriptional chromatin modifications during transcription, which is affected by the strength of histone–DNA interactions.
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Affiliation(s)
- John B Crickard
- Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Penn State University, University Park, PA 16802, USA
| | - Jaehyoun Lee
- Department of Chemistry, Penn State University, University Park, PA 16802, USA
| | - Tae-Hee Lee
- Department of Chemistry, Penn State University, University Park, PA 16802, USA
| | - Joseph C Reese
- Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Penn State University, University Park, PA 16802, USA
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193
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Chen P, Li G. Structure and Epigenetic Regulation of Chromatin Fibers. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2017; 82:25-35. [PMID: 29167282 DOI: 10.1101/sqb.2017.82.033795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In eukaryotes, genomic DNA is hierarchically packaged by histones into chromatin on several levels to fit inside the nucleus. As a central-level structure between nucleosomal arrays and higher-order chromatin organizations, the 30-nm chromatin fiber and its dynamics play a crucial role in gene regulation. However, despite considerable efforts over the past three decades, the fundamental structure and its dynamic regulation of chromatin fibers still remain as a big challenge in molecular biology. Here, we mainly summarize the most recent progress in elucidating the structure of the 30-nm chromatin fiber in vitro and epigenetic regulation of chromatin fibers by chromatin factors, particularly histone variants. In addition, we also discuss recent studies in unraveling the three-dimensional organization of chromatin fibers in situ by genomic approaches and electron microscopy.
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Affiliation(s)
- Ping Chen
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Guohong Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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194
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Wang AH, Juan AH, Ko KD, Tsai PF, Zare H, Dell'Orso S, Sartorelli V. The Elongation Factor Spt6 Maintains ESC Pluripotency by Controlling Super-Enhancers and Counteracting Polycomb Proteins. Mol Cell 2017; 68:398-413.e6. [PMID: 29033324 DOI: 10.1016/j.molcel.2017.09.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/23/2017] [Accepted: 09/12/2017] [Indexed: 01/07/2023]
Abstract
Spt6 coordinates nucleosome dis- and re-assembly, transcriptional elongation, and mRNA processing. Here, we report that depleting Spt6 in embryonic stem cells (ESCs) reduced expression of pluripotency factors, increased expression of cell-lineage-affiliated developmental regulators, and induced cell morphological and biochemical changes indicative of ESC differentiation. Selective downregulation of pluripotency factors upon Spt6 depletion may be mechanistically explained by its enrichment at ESC super-enhancers, where Spt6 controls histone H3K27 acetylation and methylation and super-enhancer RNA transcription. In ESCs, Spt6 interacted with the PRC2 core subunit Suz12 and prevented H3K27me3 accumulation at ESC super-enhancers and associated promoters. Biochemical as well as functional experiments revealed that Spt6 could compete for binding of the PRC2 methyltransferase Ezh2 to Suz12 and reduce PRC2 chromatin engagement. Thus, in addition to serving as a histone chaperone and transcription elongation factor, Spt6 counteracts repression by opposing H3K27me3 deposition at critical genomic regulatory regions.
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Affiliation(s)
- A Hongjun Wang
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20829, USA
| | - Aster H Juan
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20829, USA
| | - Kyung Dae Ko
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20829, USA
| | - Pei-Fang Tsai
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20829, USA
| | - Hossein Zare
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20829, USA
| | - Stefania Dell'Orso
- High-Throughput Sequencing Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20829, USA
| | - Vittorio Sartorelli
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20829, USA.
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195
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van den Berg AA, Depken M. Crowding-induced transcriptional bursts dictate polymerase and nucleosome density profiles along genes. Nucleic Acids Res 2017; 45:7623-7632. [PMID: 28586463 PMCID: PMC5737439 DOI: 10.1093/nar/gkx513] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/03/2017] [Indexed: 12/20/2022] Open
Abstract
During eukaryotic transcription, RNA polymerase (RNAP) translocates along DNA molecules covered with nucleosomes and other DNA binding proteins. Though the interactions between a single nucleosome and RNAP are by now fairly well understood, this understanding has not been synthesized into a description of transcription on crowded genes, where multiple RNAP transcribe through nucleosomes while preserving the nucleosome coverage. We here take a deductive modeling approach to establish the consequences of RNAP–nucleosome interactions for transcription in crowded environments. We show that under physiologically crowded conditions, the interactions of RNAP with nucleosomes induce a strong kinetic attraction between RNAP molecules, causing them to self-organize into stable and moving pelotons. The peloton formation quantitatively explains the observed nucleosome and RNAP depletion close to the initiation site on heavily transcribed genes. Pelotons further translate into short-timescale transcriptional bursts at termination, resulting in burst characteristics consistent with instances of bursty transcription observed in vivo. To facilitate experimental testing of our proposed mechanism, we present several analytic relations that make testable quantitative predictions.
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Affiliation(s)
- Aafke A van den Berg
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
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196
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Sebastian R, Oberdoerffer P. Transcription-associated events affecting genomic integrity. Philos Trans R Soc Lond B Biol Sci 2017; 372:20160288. [PMID: 28847825 PMCID: PMC5577466 DOI: 10.1098/rstb.2016.0288] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2017] [Indexed: 12/25/2022] Open
Abstract
Accurate maintenance of genomic as well as epigenomic integrity is critical for proper cell and organ function. Continuous exposure to DNA damage is, thus, often associated with malignant transformation and degenerative diseases. A significant, chronic threat to genome integrity lies in the process of transcription, which can result in the formation of potentially harmful RNA : DNA hybrid structures (R-loops) and has been linked to DNA damage accumulation as well as dynamic chromatin reorganization. In sharp contrast, recent evidence suggests that active transcription, the resulting transcripts as well as R-loop formation can play multi-faceted roles in maintaining and restoring genome integrity. Here, we will discuss the emerging contributions of transcription as both a source of DNA damage and a mediator of DNA repair. We propose that both aspects have significant implications for genome maintenance, and will speculate on possible long-term consequences for the epigenetic integrity of transcribing cells.This article is part of the themed issue 'Chromatin modifiers and remodellers in DNA repair and signalling'.
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Affiliation(s)
- Robin Sebastian
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Building 41, Room B907, Bethesda, MD 20892, USA
| | - Philipp Oberdoerffer
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Building 41, Room B907, Bethesda, MD 20892, USA
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197
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Lee J, Choi ES, Lee D. It's fun to transcribe with Fun30: A model for nucleosome dynamics during RNA polymerase II-mediated elongation. Transcription 2017; 9:108-116. [PMID: 28925811 DOI: 10.1080/21541264.2017.1356434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The ability of elongating RNA polymerase II (RNAPII) to regulate the nucleosome barrier is poorly understood because we do not know enough about the involved factors and we lack a conceptual framework to model this process. Our group recently identified the conserved Fun30/SMARCAD1 family chromatin-remodeling factor, Fun30Fft3, as being critical for relieving the nucleosome barrier during RNAPII-mediated elongation, and proposed a model illustrating how Fun30Fft3 may contribute to nucleosome disassembly during RNAPII-mediated elongation. Here, we present a model that describes nucleosome dynamics during RNAPII-mediated elongation in mathematical terms and addresses the involvement of Fun30Fft3 in this process.
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Affiliation(s)
- Junwoo Lee
- a Department of Biological Sciences , Korea Advanced Institute of Science and Technology , Daejeon , South Korea
| | - Eun Shik Choi
- a Department of Biological Sciences , Korea Advanced Institute of Science and Technology , Daejeon , South Korea
| | - Daeyoup Lee
- a Department of Biological Sciences , Korea Advanced Institute of Science and Technology , Daejeon , South Korea
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198
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Grasser M, Grasser KD. The plant RNA polymerase II elongation complex: A hub coordinating transcript elongation and mRNA processing. Transcription 2017; 9:117-122. [PMID: 28886274 DOI: 10.1080/21541264.2017.1356902] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Characterisation of the Arabidopsis RNA polymerase II (RNAPII) elongation complex revealed an assembly of a conserved set of transcript elongation factors associated with chromatin remodellers, histone modifiers as well as with various pre-mRNA splicing and polyadenylation factors. Therefore, transcribing RNAPII streamlines the processes of mRNA synthesis and processing in plants.
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Affiliation(s)
- Marion Grasser
- a Department of Cell Biology & Plant Biochemistry, Biochemistry Centre , University of Regensburg , Regensburg , Germany
| | - Klaus D Grasser
- a Department of Cell Biology & Plant Biochemistry, Biochemistry Centre , University of Regensburg , Regensburg , Germany
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199
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Safina A, Cheney P, Pal M, Brodsky L, Ivanov A, Kirsanov K, Lesovaya E, Naberezhnov D, Nesher E, Koman I, Wang D, Wang J, Yakubovskaya M, Winkler D, Gurova K. FACT is a sensor of DNA torsional stress in eukaryotic cells. Nucleic Acids Res 2017; 45:1925-1945. [PMID: 28082391 PMCID: PMC5389579 DOI: 10.1093/nar/gkw1366] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 12/29/2016] [Indexed: 02/01/2023] Open
Abstract
Transitions of B-DNA to alternative DNA structures (ADS) can be triggered by negative torsional strain, which occurs during replication and transcription, and may lead to genomic instability. However, how ADS are recognized in cells is unclear. We found that the binding of candidate anticancer drug, curaxin, to cellular DNA results in uncoiling of nucleosomal DNA, accumulation of negative supercoiling and conversion of multiple regions of genomic DNA into left-handed Z-form. Histone chaperone FACT binds rapidly to the same regions via the SSRP1 subunit in curaxin-treated cells. In vitro binding of purified SSRP1 or its isolated CID domain to a methylated DNA fragment containing alternating purine/pyrimidines, which is prone to Z-DNA transition, is much stronger than to other types of DNA. We propose that FACT can recognize and bind Z-DNA or DNA in transition from a B to Z form. Binding of FACT to these genomic regions triggers a p53 response. Furthermore, FACT has been shown to bind to other types of ADS through a different structural domain, which also leads to p53 activation. Thus, we propose that FACT acts as a sensor of ADS formation in cells. Recognition of ADS by FACT followed by a p53 response may explain the role of FACT in DNA damage prevention.
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Affiliation(s)
- Alfiya Safina
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14127, USA
| | - Peter Cheney
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14127, USA
| | - Mahadeb Pal
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14127, USA
| | - Leonid Brodsky
- Department of Evolutionary & Environmental Biology, Tauber Bioinformatics Research Center, University of Haifa, Mount Carmel, Haifa 31905, Israel
| | - Alexander Ivanov
- Department of Chemical Carcinogenesis, Institute of Carcinogenesis, Blokhin Cancer Research Center RAMS, Moscow 115478, Russia
| | - Kirill Kirsanov
- Department of Chemical Carcinogenesis, Institute of Carcinogenesis, Blokhin Cancer Research Center RAMS, Moscow 115478, Russia
| | - Ekaterina Lesovaya
- Department of Chemical Carcinogenesis, Institute of Carcinogenesis, Blokhin Cancer Research Center RAMS, Moscow 115478, Russia.,I.P. Pavlov Ryazan State Medical University, Ryazan, Russia
| | - Denis Naberezhnov
- Department of Chemical Carcinogenesis, Institute of Carcinogenesis, Blokhin Cancer Research Center RAMS, Moscow 115478, Russia
| | - Elimelech Nesher
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14127, USA.,Department of Molecular Biology, Ariel University, Ariel 40700, Israel
| | - Igor Koman
- Department of Molecular Biology, Ariel University, Ariel 40700, Israel
| | - Dan Wang
- Department of Bioinformatics, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14127, USA
| | - Jianming Wang
- Department of Bioinformatics, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14127, USA
| | - Marianna Yakubovskaya
- Department of Chemical Carcinogenesis, Institute of Carcinogenesis, Blokhin Cancer Research Center RAMS, Moscow 115478, Russia
| | - Duane Winkler
- Department of Molecular and Cell Biology, University of Texas at Dallas, 800 W. Campbell Rd., Richardson, TX 75080, USA
| | - Katerina Gurova
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14127, USA
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200
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Abstract
Skeletal muscle regeneration is an efficient stem cell-based repair system that ensures healthy musculature. For this repair system to function continuously throughout life, muscle stem cells must contribute to the process of myofiber repair as well as repopulation of the stem cell niche. The decision made by the muscle stem cells to commit to the muscle repair or to remain a stem cell depends upon patterns of gene expression, a process regulated at the epigenetic level. Indeed, it is well accepted that dynamic changes in epigenetic landscapes to control DNA accessibility and expression is a critical component during myogenesis for the effective repair of damaged muscle. Changes in the epigenetic landscape are governed by various posttranslational histone tail modifications, nucleosome repositioning, and DNA methylation events which collectively allow the control of changes in transcription networks during transitions of satellite cells from a dormant quiescent state toward terminal differentiation. This chapter focuses upon the specific epigenetic changes that occur during muscle stem cell-mediated regeneration to ensure myofiber repair and continuity of the stem cell compartment. Furthermore, we explore open questions in the field that are expected to be important areas of exploration as we move toward a more thorough understanding of the epigenetic mechanism regulating muscle regeneration.
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Affiliation(s)
- Daniel C L Robinson
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada; University of Ottawa, Ottawa, ON, Canada
| | - Francis J Dilworth
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada; University of Ottawa, Ottawa, ON, Canada.
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