1
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Korolenko A, Skinner MK. Generational stability of epigenetic transgenerational inheritance facilitates adaptation and evolution. Epigenetics 2024; 19:2380929. [PMID: 39104183 PMCID: PMC11305060 DOI: 10.1080/15592294.2024.2380929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 06/29/2024] [Accepted: 07/11/2024] [Indexed: 08/07/2024] Open
Abstract
The epigenome and epigenetic inheritance were not included in the original modern synthesis theory or more recent extended evolutionary synthesis of evolution. In a broad range of species, the environment has been shown to play a significant role in natural selection, which more recently has been shown to occur through epigenetic alterations and epigenetic inheritance. However, even with this evidence, the field of epigenetics and epigenetic inheritance has been left out of modern evolutionary synthesis, as well as other current evolutionary models. Epigenetic mechanisms can direct the regulation of genetic processes (e.g. gene expression) and also can be directly changed by the environment. In contrast, DNA sequence cannot be directly altered by the environment. The goal of this review is to present the evidence of how epigenetics and epigenetic inheritance can alter phenotypic variation in numerous species. This can occur at a significantly higher frequency than genetic change, so correlates with the frequency of evolutionary change. In addition, the concept and importance of generational stability of transgenerational inheritance is incorporated into evolutionary theory. For there to be a better understanding of evolutionary biology, we must incorporate all aspects of molecular (e.g. genetics and epigenetics) and biological sciences (e.g. environment and adaptation).
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Affiliation(s)
- Alexandra Korolenko
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Michael K. Skinner
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA, USA
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2
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Tian Y, Zhang C, Tian X, Zhang L, Yin T, Dang Y, Liu Y, Lou H, He Q. H3T11 phosphorylation by CKII is required for heterochromatin formation in Neurospora. Nucleic Acids Res 2024; 52:9536-9550. [PMID: 39106166 PMCID: PMC11381320 DOI: 10.1093/nar/gkae664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 06/19/2024] [Accepted: 07/22/2024] [Indexed: 08/09/2024] Open
Abstract
Heterochromatin is a key feature of eukaryotic genomes and is crucial for maintaining genomic stability. In fission yeast, heterochromatin nucleation is mainly mediated by DNA-binding proteins or the RNA interference (RNAi) pathway. In the filamentous fungus Neurospora crassa, however, the mechanism that causes the initiation of heterochromatin at the relics of repeat-induced point mutation is unknown and independent of the classical RNAi pathway. Here, we show that casein kinase II (CKII) and its kinase activity are required for heterochromatin formation at the well-defined 5-kb heterochromatin of the 5H-cat-3 region and transcriptional repression of its adjacent cat-3 gene. Similarly, mutation of the histone H3 phosphorylation site T11 also impairs heterochromatin formation at the same locus. The catalytic subunit CKA colocalizes with H3T11 phosphorylation (H3pT11) within the 5H-cat-3 domain and the deletion of cka results in a significant decrease in H3T11 phosphorylation. Furthermore, the loss of kinase activity of CKII results in a significant reduction of H3pT11, H3K9me3 (histone H3 lysine 9 trimethylation) and DNA methylation levels, suggesting that CKII regulates heterochromatin formation by promoting H3T11 phosphorylation. Together, our results establish that histone H3 phosphorylation by CKII is a critical event required for heterochromatin formation.
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Affiliation(s)
- Yuan Tian
- MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Chengcheng Zhang
- MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiang Tian
- MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Lu Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Tong Yin
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Yunkun Dang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Yi Liu
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Huiqiang Lou
- MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Qun He
- MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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3
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Sahu RK, Dhakshnamoorthy J, Jain S, Folco HD, Wheeler D, Grewal SIS. Nucleosome remodeler exclusion by histone deacetylation enforces heterochromatic silencing and epigenetic inheritance. Mol Cell 2024; 84:3175-3191.e8. [PMID: 39096900 DOI: 10.1016/j.molcel.2024.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 07/03/2024] [Accepted: 07/09/2024] [Indexed: 08/05/2024]
Abstract
Heterochromatin enforces transcriptional gene silencing and can be epigenetically inherited, but the underlying mechanisms remain unclear. Here, we show that histone deacetylation, a conserved feature of heterochromatin domains, blocks SWI/SNF subfamily remodelers involved in chromatin unraveling, thereby stabilizing modified nucleosomes that preserve gene silencing. Histone hyperacetylation, resulting from either the loss of histone deacetylase (HDAC) activity or the direct targeting of a histone acetyltransferase to heterochromatin, permits remodeler access, leading to silencing defects. The requirement for HDAC in heterochromatin silencing can be bypassed by impeding SWI/SNF activity. Highlighting the crucial role of remodelers, merely targeting SWI/SNF to heterochromatin, even in cells with functional HDAC, increases nucleosome turnover, causing defective gene silencing and compromised epigenetic inheritance. This study elucidates a fundamental mechanism whereby histone hypoacetylation, maintained by high HDAC levels in heterochromatic regions, ensures stable gene silencing and epigenetic inheritance, providing insights into genome regulatory mechanisms relevant to human diseases.
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Affiliation(s)
- Rakesh Kumar Sahu
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jothy Dhakshnamoorthy
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shweta Jain
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hernan Diego Folco
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Wheeler
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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4
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Yu J, Zhang Y, Fang Y, Paulo JA, Yaghoubi D, Hua X, Shipkovenska G, Toda T, Zhang Z, Gygi SP, Jia S, Li Q, Moazed D. A replisome-associated histone H3-H4 chaperone required for epigenetic inheritance. Cell 2024; 187:5010-5028.e24. [PMID: 39094570 PMCID: PMC11380579 DOI: 10.1016/j.cell.2024.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 03/17/2024] [Accepted: 07/03/2024] [Indexed: 08/04/2024]
Abstract
Faithful transfer of parental histones to newly replicated daughter DNA strands is critical for inheritance of epigenetic states. Although replication proteins that facilitate parental histone transfer have been identified, how intact histone H3-H4 tetramers travel from the front to the back of the replication fork remains unknown. Here, we use AlphaFold-Multimer structural predictions combined with biochemical and genetic approaches to identify the Mrc1/CLASPIN subunit of the replisome as a histone chaperone. Mrc1 contains a conserved histone-binding domain that forms a brace around the H3-H4 tetramer mimicking nucleosomal DNA and H2A-H2B histones, is required for heterochromatin inheritance, and promotes parental histone recycling during replication. We further identify binding sites for the FACT histone chaperone in Swi1/TIMELESS and DNA polymerase α that are required for heterochromatin inheritance. We propose that Mrc1, in concert with FACT acting as a mobile co-chaperone, coordinates the distribution of parental histones to newly replicated DNA.
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Affiliation(s)
- Juntao Yu
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Yujie Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Yimeng Fang
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Dadmehr Yaghoubi
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Xu Hua
- Institute for Cancer Genetics, Department of Pediatrics, and Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Gergana Shipkovenska
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Takenori Toda
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Zhiguo Zhang
- Institute for Cancer Genetics, Department of Pediatrics, and Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Songtao Jia
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Qing Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.
| | - Danesh Moazed
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
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5
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Peterson CL. Heterochromatin: Hiding from the remodeling machines. Mol Cell 2024; 84:3167-3169. [PMID: 39241749 DOI: 10.1016/j.molcel.2024.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2024] [Revised: 08/07/2024] [Accepted: 08/07/2024] [Indexed: 09/09/2024]
Abstract
In this issue of Molecular Cell, Sahu et al.1 find that shielding heterochromatin from SWI/SNF chromatin remodelers is essential to maintain and epigenetically propagate pre-existing heterochromatin domains, whereas SWI/SNF action protects facultative heterochromatic regions from premature silencing.
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Affiliation(s)
- Craig L Peterson
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
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6
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Toda T, Fang Y, Shan CM, Hua X, Kim JK, Tang LC, Jovanovic M, Tong L, Qiao F, Zhang Z, Jia S. Mrc1 regulates parental histone segregation and heterochromatin inheritance. Mol Cell 2024; 84:3223-3236.e4. [PMID: 39094566 PMCID: PMC11414769 DOI: 10.1016/j.molcel.2024.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 06/07/2024] [Accepted: 07/03/2024] [Indexed: 08/04/2024]
Abstract
Chromatin-based epigenetic memory relies on the symmetric distribution of parental histones to newly synthesized daughter DNA strands, aided by histone chaperones within the DNA replication machinery. However, the mechanism of parental histone transfer remains elusive. Here, we reveal that in fission yeast, the replisome protein Mrc1 plays a crucial role in promoting the transfer of parental histone H3-H4 to the lagging strand, ensuring proper heterochromatin inheritance. In addition, Mrc1 facilitates the interaction between Mcm2 and DNA polymerase alpha, two histone-binding proteins critical for parental histone transfer. Furthermore, Mrc1's involvement in parental histone transfer and epigenetic inheritance is independent of its known functions in DNA replication checkpoint activation and replisome speed control. Instead, Mrc1 interacts with Mcm2 outside of its histone-binding region, creating a physical barrier to separate parental histone transfer pathways. These findings unveil Mrc1 as a key player within the replisome, coordinating parental histone segregation to regulate epigenetic inheritance.
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Affiliation(s)
- Takenori Toda
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Yimeng Fang
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Chun-Min Shan
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Xu Hua
- Institute for Cancer Genetics, Department of Pediatrics, and Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jin-Kwang Kim
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697, USA
| | | | - Marko Jovanovic
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Feng Qiao
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697, USA
| | - Zhiguo Zhang
- Institute for Cancer Genetics, Department of Pediatrics, and Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Songtao Jia
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
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7
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Inada N. Regulation of heterochromatin organization in plants. JOURNAL OF PLANT RESEARCH 2024; 137:685-693. [PMID: 38914831 DOI: 10.1007/s10265-024-01550-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 05/27/2024] [Indexed: 06/26/2024]
Abstract
Heterochromatin is a nuclear area that contains highly condensed and transcriptionally inactive chromatin. Alterations in the organization of heterochromatin are correlated with changes in gene expression and genome stability, which affect various aspects of plant life. Thus, studies of the molecular mechanisms that regulate heterochromatin organization are important for understanding the regulation of plant physiology. Microscopically, heterochromatin can be characterized as chromocenters that are intensely stained with DNA-binding fluorescent dyes. Arabidopsis thaliana exhibits distinctive chromocenters in interphase nuclei, and genetic studies combined with cytological analyses have identified a number of factors that are involved in heterochromatin assembly and organization. In this review, I will summarize the factors involved in the regulation of heterochromatin organization in plants.
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Affiliation(s)
- Noriko Inada
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, 599-8531, Osaka, Japan.
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8
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Zhang W, Cheng L, Li K, Xie L, Ji J, Lei X, Jiang A, Chen C, Li H, Li P, Sun Q. Evolutional heterochromatin condensation delineates chromocenter formation and retrotransposon silencing in plants. NATURE PLANTS 2024; 10:1215-1230. [PMID: 39014153 DOI: 10.1038/s41477-024-01746-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 06/20/2024] [Indexed: 07/18/2024]
Abstract
Heterochromatic condensates (chromocenters) are critical for maintaining the silencing of heterochromatin. It is therefore puzzling that the presence of chromocenters is variable across plant species. Here we reveal that variations in the plant heterochromatin protein ADCP1 confer a diversity in chromocenter formation via phase separation. ADCP1 physically interacts with the high mobility group protein HMGA to form a complex and mediates heterochromatin condensation by multivalent interactions. The loss of intrinsically disordered regions (IDRs) in ADCP1 homologues during evolution has led to the absence of prominent chromocenter formation in various plant species, and introduction of IDR-containing ADCP1 with HMGA promotes heterochromatin condensation and retrotransposon silencing. Moreover, plants in the Cucurbitaceae group have evolved an IDR-containing chimaera of ADCP1 and HMGA, which remarkably enables formation of chromocenters. Together, our work uncovers a coevolved mechanism of phase separation in packing heterochromatin and silencing retrotransposons.
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Affiliation(s)
- Weifeng Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Lingling Cheng
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Kuan Li
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Leiming Xie
- Tsinghua-Peking Center for Life Sciences, Beijing, China
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jinyao Ji
- Tsinghua-Peking Center for Life Sciences, Beijing, China
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xue Lei
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Anjie Jiang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Chunlai Chen
- Tsinghua-Peking Center for Life Sciences, Beijing, China
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Haitao Li
- Tsinghua-Peking Center for Life Sciences, Beijing, China
- State Key Laboratory of Molecular Oncology, MOE Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, SXMU-Tsinghua Collaborative Innovation Center for Frontier Medicine, School of Medicine, Tsinghua University, Beijing, China
| | - Pilong Li
- Tsinghua-Peking Center for Life Sciences, Beijing, China
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China.
- Tsinghua-Peking Center for Life Sciences, Beijing, China.
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9
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Aguirre S, Pappa S, Serna-Pujol N, Padilla N, Iacobucci S, Nacht AS, Vicent GP, Jordan A, de la Cruz X, Martínez-Balbás MA. PHF2-mediated H3K9me balance orchestrates heterochromatin stability and neural progenitor proliferation. EMBO Rep 2024; 25:3486-3505. [PMID: 38890452 PMCID: PMC11315909 DOI: 10.1038/s44319-024-00178-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 05/18/2024] [Accepted: 06/04/2024] [Indexed: 06/20/2024] Open
Abstract
Heterochromatin stability is crucial for progenitor proliferation during early neurogenesis. It relays on the maintenance of local hubs of H3K9me. However, understanding the formation of efficient localized levels of H3K9me remains limited. To address this question, we used neural stem cells to analyze the function of the H3K9me2 demethylase PHF2, which is crucial for progenitor proliferation. Through mass-spectroscopy and genome-wide assays, we show that PHF2 interacts with heterochromatin components and is enriched at pericentromeric heterochromatin (PcH) boundaries where it maintains transcriptional activity. This binding is essential for silencing the satellite repeats, preventing DNA damage and genome instability. PHF2's depletion increases the transcription of heterochromatic repeats, accompanied by a decrease in H3K9me3 levels and alterations in PcH organization. We further show that PHF2's PHD and catalytic domains are crucial for maintaining PcH stability, thereby safeguarding genome integrity. These results highlight the multifaceted nature of PHF2's functions in maintaining heterochromatin stability and regulating gene expression during neural development. Our study unravels the intricate relationship between heterochromatin stability and progenitor proliferation during mammalian neurogenesis.
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Affiliation(s)
- Samuel Aguirre
- Department of Structural and Molecular Biology, Instituto de Biología Molecular de Barcelona (IBMB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, 08028, Spain
| | - Stella Pappa
- Department of Structural and Molecular Biology, Instituto de Biología Molecular de Barcelona (IBMB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, 08028, Spain
| | - Núria Serna-Pujol
- Department of Structural and Molecular Biology, Instituto de Biología Molecular de Barcelona (IBMB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, 08028, Spain
| | - Natalia Padilla
- Vall d'Hebron Institute of Research (VHIR), Passeig de la Vall d'Hebron, 119, E-08035, Barcelona, Spain
| | - Simona Iacobucci
- Department of Structural and Molecular Biology, Instituto de Biología Molecular de Barcelona (IBMB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, 08028, Spain
| | - A Silvina Nacht
- Center for Genomic Regulation (CRG), Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Guillermo P Vicent
- Department of Structural and Molecular Biology, Instituto de Biología Molecular de Barcelona (IBMB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, 08028, Spain
| | - Albert Jordan
- Department of Structural and Molecular Biology, Instituto de Biología Molecular de Barcelona (IBMB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, 08028, Spain
| | - Xavier de la Cruz
- Vall d'Hebron Institute of Research (VHIR), Passeig de la Vall d'Hebron, 119, E-08035, Barcelona, Spain
- Institut Català per la Recerca i Estudis Avançats (ICREA), Barcelona, 08018, Spain
| | - Marian A Martínez-Balbás
- Department of Structural and Molecular Biology, Instituto de Biología Molecular de Barcelona (IBMB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, 08028, Spain.
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10
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Huang Z, Cui W, Ratnayake I, Tawil R, Pfeifer GP. SMCHD1 maintains heterochromatin and genome compartments in human myoblasts. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.07.602392. [PMID: 39026812 PMCID: PMC11257445 DOI: 10.1101/2024.07.07.602392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Mammalian genomes are subdivided into euchromatic A compartments that contain mostly active chromatin, and inactive, heterochromatic B compartments. However, it is unknown how A and B genome compartments are established and maintained. Here we studied SMCHD1, an SMC-like protein in human male myoblasts. SMCHD1 colocalizes with Lamin B1 and the heterochromatin mark H3K9me3. Loss of SMCHD1 leads to extensive heterochromatin depletion at the nuclear lamina and acquisition of active chromatin states along all chromosomes. In absence of SMCHD1, long range intra-chromosomal and inter-chromosomal contacts between B compartments are lost while many new TADs and loops are formed. Inactivation of SMCHD1 promotes numerous B to A compartment transitions accompanied by activation of silenced genes. SMCHD1 functions as an anchor for heterochromatin domains ensuring that these domains are inaccessible to epigenome modification enzymes that typically operate in active chromatin. Therefore, A compartments are formed by default when not prevented by SMCHD1.
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11
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Ma R, Zhang Y, Zhang J, Zhang P, Liu Z, Fan Y, Wang HT, Zhang Z, Zhu B. Targeting pericentric non-consecutive motifs for heterochromatin initiation. Nature 2024; 631:678-685. [PMID: 38961301 DOI: 10.1038/s41586-024-07640-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 05/31/2024] [Indexed: 07/05/2024]
Abstract
Pericentric heterochromatin is a critical component of chromosomes marked by histone H3 K9 (H3K9) methylation1-3. However, what recruits H3K9-specific histone methyltransferases to pericentric regions in vertebrates remains unclear4, as does why pericentric regions in different species share the same H3K9 methylation mark despite lacking highly conserved DNA sequences2,5. Here we show that zinc-finger proteins ZNF512 and ZNF512B specifically localize at pericentric regions through direct DNA binding. Notably, both ZNF512 and ZNF512B are sufficient to initiate de novo heterochromatin formation at ectopically targeted repetitive regions and pericentric regions, as they directly recruit SUV39H1 and SUV39H2 (SUV39H) to catalyse H3K9 methylation. SUV39H2 makes a greater contribution to H3K9 trimethylation, whereas SUV39H1 seems to contribute more to silencing, probably owing to its preferential association with HP1 proteins. ZNF512 and ZNF512B from different species can specifically target pericentric regions of other vertebrates, because the atypical long linker residues between the zinc-fingers of ZNF512 and ZNF512B offer flexibility in recognition of non-consecutively organized three-nucleotide triplets targeted by each zinc-finger. This study addresses two long-standing questions: how constitutive heterochromatin is initiated and how seemingly variable pericentric sequences are targeted by the same set of conserved machinery in vertebrates.
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Affiliation(s)
- Runze Ma
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yan Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, China
| | - Jing Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, China
| | - Pinqi Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zeqi Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yiming Fan
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Hao-Tian Wang
- State Key Laboratory of Genetic Resources and Evolution/Key Laboratory of Healthy Aging Research of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Zhuqiang Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, China
| | - Bing Zhu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
- Key Laboratory of Epigenetic Regulation and Intervention, Chinese Academy of Sciences, Beijing, China.
- New Cornerstone Science Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
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12
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Atinbayeva N, Valent I, Zenk F, Loeser E, Rauer M, Herur S, Quarato P, Pyrowolakis G, Gomez-Auli A, Mittler G, Cecere G, Erhardt S, Tiana G, Zhan Y, Iovino N. Inheritance of H3K9 methylation regulates genome architecture in Drosophila early embryos. EMBO J 2024; 43:2685-2714. [PMID: 38831123 PMCID: PMC11217351 DOI: 10.1038/s44318-024-00127-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/27/2024] [Accepted: 04/15/2024] [Indexed: 06/05/2024] Open
Abstract
Constitutive heterochromatin is essential for transcriptional silencing and genome integrity. The establishment of constitutive heterochromatin in early embryos and its role in early fruitfly development are unknown. Lysine 9 trimethylation of histone H3 (H3K9me3) and recruitment of its epigenetic reader, heterochromatin protein 1a (HP1a), are hallmarks of constitutive heterochromatin. Here, we show that H3K9me3 is transmitted from the maternal germline to the next generation. Maternally inherited H3K9me3, and the histone methyltransferases (HMT) depositing it, are required for the organization of constitutive heterochromatin: early embryos lacking H3K9 methylation display de-condensation of pericentromeric regions, centromere-centromere de-clustering, mitotic defects, and nuclear shape irregularities, resulting in embryo lethality. Unexpectedly, quantitative CUT&Tag and 4D microscopy measurements of HP1a coupled with biophysical modeling revealed that H3K9me2/3 is largely dispensable for HP1a recruitment. Instead, the main function of H3K9me2/3 at this developmental stage is to drive HP1a clustering and subsequent heterochromatin compaction. Our results show that HP1a binding to constitutive heterochromatin in the absence of H3K9me2/3 is not sufficient to promote proper embryo development and heterochromatin formation. The loss of H3K9 HMTs and H3K9 methylation alters genome organization and hinders embryonic development.
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Affiliation(s)
- Nazerke Atinbayeva
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
- Albert-Ludwigs-Universität Freiburg, Fahnenbergplatz, 79085, Freiburg im Breisgau, Germany
| | - Iris Valent
- Karlsruhe Institute of Technology (KIT), Zoological Institute, 76131, Karlsruhe, Germany
| | - Fides Zenk
- Brain Mind Institute, School of Life Sciences EPFL, SV3809, 1015, Lausanne, Switzerland
| | - Eva Loeser
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Michael Rauer
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Shwetha Herur
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Piergiuseppe Quarato
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Giorgos Pyrowolakis
- Centre for Biological signaling studies, University of Freiburg, 79104, Freiburg im Breisgau, Germany
| | - Alejandro Gomez-Auli
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Gerhard Mittler
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Germano Cecere
- Institute Pasteur, Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, UMR3738, CNRS, 75724, Cedex 15, Paris, France
| | - Sylvia Erhardt
- Karlsruhe Institute of Technology (KIT), Zoological Institute, 76131, Karlsruhe, Germany
| | - Guido Tiana
- Università degli Studi di Milano and INFN, Milan, Italy
| | - Yinxiu Zhan
- Department of Experimental Oncology, European Institute of Oncology-IRCCS, Milan, Italy.
| | - Nicola Iovino
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany.
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13
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Takahata S, Taguchi A, Takenaka A, Mori M, Chikashige Y, Tsutsumi C, Hiraoka Y, Murakami Y. The HMG-box module in FACT is critical for suppressing epigenetic variegation of heterochromatin in fission yeast. Genes Cells 2024; 29:567-583. [PMID: 38837646 DOI: 10.1111/gtc.13132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/08/2024] [Accepted: 05/14/2024] [Indexed: 06/07/2024]
Abstract
Chromatin condensation state is the key for retrieving genetic information. High-mobility group protein (HMG) proteins exhibit DNA-binding and bending activities, playing an important role in the regulation of chromatin structure. We have shown that nucleosomes tightly packaged into heterochromatin undergo considerable dynamic histone H2A-H2B maintenance via the direct interaction between HP1/Swi6 and facilitate chromatin transcription (FACT), which is composed of the Spt16/Pob3 heterodimer and Nhp6. In this study, we analyzed the role of Nhp6, an HMG box protein, in the FACT at heterochromatin. Pob3 mutant strains showed derepressed heterochromatin-dependent gene silencing, whereas Nhp6 mutant strains did not show significant defects in chromatin regulation or gene expression, suggesting that these two modules play different roles in chromatin regulation. We expressed a protein fusing Nhp6 to the C-terminus of Pob3, which mimics the multicellular FACT component Ssrp1. The chromatin-binding activity of FACT increased with the number of Nhp6 fused to Pob3, and the heterochromatin formation rate was promoted more strongly. Furthermore, we demonstrated that this promotion of heterochromatinization inhibited the heterochromatic variegation caused by epe1+ disruption. Heterochromatic variegation can be observed in a variety of regulatory steps; however, when it is caused by fluctuations in chromatin arrangement, it can be eliminated through the strong recruitment of the FACT complex.
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Affiliation(s)
- Shinya Takahata
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Japan
| | - Asahi Taguchi
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Ayaka Takenaka
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Miyuki Mori
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Yuji Chikashige
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Japan
| | - Chihiro Tsutsumi
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Japan
| | - Yasushi Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Yota Murakami
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Japan
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14
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Ciapponi M, Karlukova E, Schkölziger S, Benda C, Müller J. Structural basis of the histone ubiquitination read-write mechanism of RYBP-PRC1. Nat Struct Mol Biol 2024; 31:1023-1027. [PMID: 38528151 PMCID: PMC11257959 DOI: 10.1038/s41594-024-01258-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 02/26/2024] [Indexed: 03/27/2024]
Abstract
Histone H2A monoubiquitination (H2Aub1) by the PRC1 subunit RING1B entails a positive feedback loop, mediated by the RING1B-interacting protein RYBP. We uncover that human RYBP-PRC1 binds unmodified nucleosomes via RING1B but H2Aub1-modified nucleosomes via RYBP. RYBP interactions with both ubiquitin and the nucleosome acidic patch create the high binding affinity that favors RYBP- over RING1B-directed PRC1 binding to H2Aub1-modified nucleosomes; this enables RING1B to monoubiquitinate H2A in neighboring unmodified nucleosomes.
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Affiliation(s)
- Maria Ciapponi
- Laboratory of Chromatin Biology, Max-Planck Institute of Biochemistry, Martinsried, Germany
| | - Elena Karlukova
- Laboratory of Chromatin Biology, Max-Planck Institute of Biochemistry, Martinsried, Germany
| | - Sven Schkölziger
- Laboratory of Chromatin Biology, Max-Planck Institute of Biochemistry, Martinsried, Germany
| | - Christian Benda
- Department of Structural Cell Biology, Max-Planck Institute of Biochemistry, Martinsried, Germany.
| | - Jürg Müller
- Laboratory of Chromatin Biology, Max-Planck Institute of Biochemistry, Martinsried, Germany.
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15
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Yabe K, Kamio A, Oya S, Kakutani T, Hirayama M, Tanaka Y, Inagaki S. H3K9 methylation regulates heterochromatin silencing through incoherent feedforward loops. SCIENCE ADVANCES 2024; 10:eadn4149. [PMID: 38924413 PMCID: PMC11204290 DOI: 10.1126/sciadv.adn4149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/22/2024] [Indexed: 06/28/2024]
Abstract
Histone H3 lysine-9 methylation (H3K9me) is a hallmark of the condensed and transcriptionally silent heterochromatin. It remains unclear how H3K9me controls transcription silencing and how cells delimit H3K9me domains to avoid silencing essential genes. Here, using Arabidopsis genetic systems that induce H3K9me2 in genes and transposons de novo, we show that H3K9me2 accumulation paradoxically also causes the deposition of the euchromatic mark H3K36me3 by a SET domain methyltransferase, ASHH3. ASHH3-induced H3K36me3 confers anti-silencing by preventing the demethylation of H3K4me1 by LDL2, which mediates transcriptional silencing downstream of H3K9me2. These results demonstrate that H3K9me2 not only facilitates but orchestrates silencing by actuating antagonistic silencing and anti-silencing pathways, providing insights into the molecular basis underlying proper partitioning of chromatin domains and the creation of metastable epigenetic variation.
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Affiliation(s)
| | | | - Satoyo Oya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | | | - Mami Hirayama
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yuriko Tanaka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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16
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Mateo-Bonmatí E, Montez M, Maple R, Fiedler M, Fang X, Saalbach G, Passmore LA, Dean C. A CPF-like phosphatase module links transcription termination to chromatin silencing. Mol Cell 2024; 84:2272-2286.e7. [PMID: 38851185 PMCID: PMC7616277 DOI: 10.1016/j.molcel.2024.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 02/28/2024] [Accepted: 05/15/2024] [Indexed: 06/10/2024]
Abstract
The interconnections between co-transcriptional regulation, chromatin environment, and transcriptional output remain poorly understood. Here, we investigate the mechanism underlying RNA 3' processing-mediated Polycomb silencing of Arabidopsis FLOWERING LOCUS C (FLC). We show a requirement for ANTHESIS PROMOTING FACTOR 1 (APRF1), a homolog of yeast Swd2 and human WDR82, known to regulate RNA polymerase II (RNA Pol II) during transcription termination. APRF1 interacts with TYPE ONE SERINE/THREONINE PROTEIN PHOSPHATASE 4 (TOPP4) (yeast Glc7/human PP1) and LUMINIDEPENDENS (LD), the latter showing structural features found in Ref2/PNUTS, all components of the yeast and human phosphatase module of the CPF 3' end-processing machinery. LD has been shown to co-associate in vivo with the histone H3 K4 demethylase FLOWERING LOCUS D (FLD). This work shows how the APRF1/LD-mediated polyadenylation/termination process influences subsequent rounds of transcription by changing the local chromatin environment at FLC.
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Affiliation(s)
- Eduardo Mateo-Bonmatí
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK; Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)/CSIC, Pozuelo de Alarcón, Madrid 28223, Spain.
| | - Miguel Montez
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Robert Maple
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Marc Fiedler
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Xiaofeng Fang
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Gerhard Saalbach
- Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | | | - Caroline Dean
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK; MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
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17
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Serra-Cardona A, Hua X, McNutt SW, Zhou H, Toda T, Jia S, Chu F, Zhang Z. The PCNA-Pol δ complex couples lagging strand DNA synthesis to parental histone transfer for epigenetic inheritance. SCIENCE ADVANCES 2024; 10:eadn5175. [PMID: 38838138 PMCID: PMC11152121 DOI: 10.1126/sciadv.adn5175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 05/01/2024] [Indexed: 06/07/2024]
Abstract
Inheritance of epigenetic information is critical for maintaining cell identity. The transfer of parental histone H3-H4 tetramers, the primary carrier of epigenetic modifications on histone proteins, represents a crucial yet poorly understood step in the inheritance of epigenetic information. Here, we show the lagging strand DNA polymerase, Pol δ, interacts directly with H3-H4 and that the interaction between Pol δ and the sliding clamp PCNA regulates parental histone transfer to lagging strands, most likely independent of their roles in DNA synthesis. When combined, mutations at Pol δ and Mcm2 that compromise parental histone transfer result in a greater reduction in nucleosome occupancy at nascent chromatin than mutations in either alone. Last, PCNA contributes to nucleosome positioning on nascent chromatin. On the basis of these results, we suggest that the PCNA-Pol δ complex couples lagging strand DNA synthesis to parental H3-H4 transfer, facilitating epigenetic inheritance.
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Affiliation(s)
- Albert Serra-Cardona
- Institute for Cancer Genetics, Department of Pediatrics and Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10019, USA
| | - Xu Hua
- Institute for Cancer Genetics, Department of Pediatrics and Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10019, USA
| | - Seth W. McNutt
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Hui Zhou
- Institute for Cancer Genetics, Department of Pediatrics and Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10019, USA
| | - Takenori Toda
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Songtao Jia
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Feixia Chu
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Zhiguo Zhang
- Institute for Cancer Genetics, Department of Pediatrics and Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10019, USA
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18
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Akilli N, Cheutin T, Cavalli G. Phase separation and inheritance of repressive chromatin domains. Curr Opin Genet Dev 2024; 86:102201. [PMID: 38701672 DOI: 10.1016/j.gde.2024.102201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 04/04/2024] [Accepted: 04/16/2024] [Indexed: 05/05/2024]
Abstract
Polycomb-associated chromatin and pericentromeric heterochromatin form genomic domains important for the epigenetic regulation of gene expression. Both Polycomb complexes and heterochromatin factors rely on 'read and write' mechanisms, which, on their own, are not sufficient to explain the formation and the maintenance of these epigenetic domains. Microscopy has revealed that they form specific nuclear compartments separated from the rest of the genome. Recently, some subunits of these molecular machineries have been shown to undergo phase separation, both in vitro and in vivo, suggesting that phase separation might play important roles in the formation and the function of these two kinds of repressive chromatin. In this review, we will present the recent advances in the field of facultative and constitutive heterochromatin formation and maintenance through phase separation.
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Affiliation(s)
- Nazli Akilli
- Institute of Human Genetics, CNRS, University of Montpellier, Montpellier, France. https://twitter.com/@sinmerank
| | - Thierry Cheutin
- Institute of Human Genetics, CNRS, University of Montpellier, Montpellier, France
| | - Giacomo Cavalli
- Institute of Human Genetics, CNRS, University of Montpellier, Montpellier, France.
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19
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Hövel I, Bader R, Louwers M, Haring M, Peek K, Gent JI, Stam M. RNA-directed DNA methylation mutants reduce histone methylation at the paramutated maize booster1 enhancer. PLANT PHYSIOLOGY 2024; 195:1161-1179. [PMID: 38366582 PMCID: PMC11142347 DOI: 10.1093/plphys/kiae072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/19/2023] [Accepted: 12/25/2023] [Indexed: 02/18/2024]
Abstract
Paramutation is the transfer of mitotically and meiotically heritable silencing information between two alleles. With paramutation at the maize (Zea mays) booster1 (b1) locus, the low-expressed B' epiallele heritably changes the high-expressed B-I epiallele into B' with 100% frequency. This requires specific tandem repeats and multiple components of the RNA-directed DNA methylation pathway, including the RNA-dependent RNA polymerase (encoded by mediator of paramutation1, mop1), the second-largest subunit of RNA polymerase IV and V (NRP(D/E)2a, encoded by mop2), and the largest subunit of RNA Polymerase IV (NRPD1, encoded by mop3). Mutations in mop genes prevent paramutation and release silencing at the B' epiallele. In this study, we investigated the effect of mutations in mop1, mop2, and mop3 on chromatin structure and DNA methylation at the B' epiallele, and especially the regulatory hepta-repeat 100 kb upstream of the b1 gene. Mutations in mop1 and mop3 resulted in decreased repressive histone modifications H3K9me2 and H3K27me2 at the hepta-repeat. Associated with this decrease were partial activation of the hepta-repeat enhancer function, formation of a multi-loop structure, and elevated b1 expression. In mop2 mutants, which do not show elevated b1 expression, H3K9me2, H3K27me2 and a single-loop structure like in wild-type B' were retained. Surprisingly, high CG and CHG methylation levels at the B' hepta-repeat remained in all three mutants, and CHH methylation was low in both wild type and mutants. Our results raise the possibility of MOP factors mediating RNA-directed histone methylation rather than RNA-directed DNA methylation at the b1 locus.
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Affiliation(s)
- Iris Hövel
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, P.O. Box 1210, 1090 GE Amsterdam, The Netherlands
| | - Rechien Bader
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, P.O. Box 1210, 1090 GE Amsterdam, The Netherlands
| | - Marieke Louwers
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, P.O. Box 1210, 1090 GE Amsterdam, The Netherlands
- argenx BV, Industriepark Zwijnaarde 7, 9052 Zwijnaarde (Ghent), Belgium
| | - Max Haring
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, P.O. Box 1210, 1090 GE Amsterdam, The Netherlands
- University Library, Universiteit van Amsterdam, P.O. Box 19185, 1000 GD Amsterdam, The Netherlands
| | - Kevin Peek
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, P.O. Box 1210, 1090 GE Amsterdam, The Netherlands
| | - Jonathan I Gent
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Maike Stam
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, P.O. Box 1210, 1090 GE Amsterdam, The Netherlands
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20
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Zhang Y, Feng J, Mi Y, Fan W, Qin R, Mei Y, Jin G, Mao J, Zhang H. Epigenetic Activation of Cytochrome P450 1A2 Sensitizes Hepatocellular Carcinoma Cells to Sorafenib. Drug Metab Dispos 2024; 52:555-564. [PMID: 38565301 DOI: 10.1124/dmd.124.001665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/08/2024] [Accepted: 03/12/2024] [Indexed: 04/04/2024] Open
Abstract
Cytochrome P450 1A2 (CYP1A2) is a known tumor suppressor in hepatocellular carcinoma (HCC), but its expression is repressed in HCC and the underlying mechanism is unclear. In this study, we investigated the epigenetic mechanisms of CYP1A2 repression and potential therapeutic implications. In HCC tumor tissues, the methylation rates of CYP1A2 CpG island (CGI) and DNA methyltransferase (DNMT) 3A protein levels were significantly higher, and there was a clear negative correlation between DNMT3A and CYP1A2 protein expression. Knockdown of DNMT3A by siRNA significantly increased CYP1A2 expression in HCC cells. Additionally, treating HCC cells with decitabine (DAC) resulted in a dose-dependent upregulation of CYP1A2 expression by reducing the methylation level of CYP1A2 CGI. Furthermore, we observed a decreased enrichment of H3K27Ac in the promoter region of CYP1A2 in HCC tissues. Treatment with the trichostatin A (TSA) restored CYP1A2 expression in HCC cells by increasing H3K27Ac levels in the CYP1A2 promoter region. Importantly, combination treatment of sorafenib with DAC or TSA resulted in a leftward shift of the dose-response curve, lower IC50 values, and reduced colony numbers in HCC cells. Our findings suggest that hypermethylation of the CGI at the promoter, mediated by the high expression of DNMT3A, and hypoacetylation of H3K27 in the CYP1A2 promoter region, leads to CYP1A2 repression in HCC. Epigenetic drugs DAC and TSA increase HCC cell sensitivity to sorafenib by restoring CYP1A2 expression. Our study provides new insights into the epigenetic regulation of CYP1A2 in HCC and highlights the potential of epigenetic drugs as a therapeutic approach for HCC. SIGNIFICANCE STATEMENT: This study marks the first exploration of the epigenetic mechanisms underlying cytochrome P450 (CYP) 1A2 suppression in hepatocellular carcinoma (HCC). Our findings reveal that heightened DNA methyltransferase expression induces hypermethylation of the CpG island at the promoter, coupled with diminished H3K27Ac levels, resulting in the repression of CYP1A2 in HCC. The use of epigenetic drugs such as decitabine and trichostatin A emerges as a novel therapeutic avenue, demonstrating their potential to restore CYP1A2 expression and enhance sorafenib sensitivity in HCC cells.
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Affiliation(s)
- Yi Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China (Y.Z., J.F., Y.M., R.Q., Y.M., G.J., H.Z.) and Zhengzhou Tobacco Research Institute of China National Tobacco Company, Zhengzhou, China (W.F., J.M.)
| | - Jingyu Feng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China (Y.Z., J.F., Y.M., R.Q., Y.M., G.J., H.Z.) and Zhengzhou Tobacco Research Institute of China National Tobacco Company, Zhengzhou, China (W.F., J.M.)
| | - Yang Mi
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China (Y.Z., J.F., Y.M., R.Q., Y.M., G.J., H.Z.) and Zhengzhou Tobacco Research Institute of China National Tobacco Company, Zhengzhou, China (W.F., J.M.)
| | - Wu Fan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China (Y.Z., J.F., Y.M., R.Q., Y.M., G.J., H.Z.) and Zhengzhou Tobacco Research Institute of China National Tobacco Company, Zhengzhou, China (W.F., J.M.)
| | - Runwen Qin
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China (Y.Z., J.F., Y.M., R.Q., Y.M., G.J., H.Z.) and Zhengzhou Tobacco Research Institute of China National Tobacco Company, Zhengzhou, China (W.F., J.M.)
| | - Yingwu Mei
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China (Y.Z., J.F., Y.M., R.Q., Y.M., G.J., H.Z.) and Zhengzhou Tobacco Research Institute of China National Tobacco Company, Zhengzhou, China (W.F., J.M.)
| | - Ge Jin
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China (Y.Z., J.F., Y.M., R.Q., Y.M., G.J., H.Z.) and Zhengzhou Tobacco Research Institute of China National Tobacco Company, Zhengzhou, China (W.F., J.M.)
| | - Jian Mao
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China (Y.Z., J.F., Y.M., R.Q., Y.M., G.J., H.Z.) and Zhengzhou Tobacco Research Institute of China National Tobacco Company, Zhengzhou, China (W.F., J.M.)
| | - Haifeng Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China (Y.Z., J.F., Y.M., R.Q., Y.M., G.J., H.Z.) and Zhengzhou Tobacco Research Institute of China National Tobacco Company, Zhengzhou, China (W.F., J.M.)
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21
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Kanata E, Duffié R, Schulz EG. Establishment and maintenance of random monoallelic expression. Development 2024; 151:dev201741. [PMID: 38813842 PMCID: PMC11166465 DOI: 10.1242/dev.201741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
This Review elucidates the regulatory principles of random monoallelic expression by focusing on two well-studied examples: the X-chromosome inactivation regulator Xist and the olfactory receptor gene family. Although the choice of a single X chromosome or olfactory receptor occurs in different developmental contexts, common gene regulatory principles guide monoallelic expression in both systems. In both cases, an event breaks the symmetry between genetically and epigenetically identical copies of the gene, leading to the expression of one single random allele, stabilized through negative feedback control. Although many regulatory steps that govern the establishment and maintenance of monoallelic expression have been identified, key pieces of the puzzle are still missing. We provide an overview of the current knowledge and models for the monoallelic expression of Xist and olfactory receptors. We discuss their similarities and differences, and highlight open questions and approaches that could guide the study of other monoallelically expressed genes.
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Affiliation(s)
- Eleni Kanata
- Systems Epigenetics, Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Rachel Duffié
- Department of Biochemistry and Molecular Biophysics, Mortimer B. Zuckerman Mind, Brain, and Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Edda G. Schulz
- Systems Epigenetics, Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
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22
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Rutherford KM, Lera-Ramírez M, Wood V. PomBase: a Global Core Biodata Resource-growth, collaboration, and sustainability. Genetics 2024; 227:iyae007. [PMID: 38376816 PMCID: PMC11075564 DOI: 10.1093/genetics/iyae007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/13/2024] [Indexed: 02/21/2024] Open
Abstract
PomBase (https://www.pombase.org), the model organism database (MOD) for fission yeast, was recently awarded Global Core Biodata Resource (GCBR) status by the Global Biodata Coalition (GBC; https://globalbiodata.org/) after a rigorous selection process. In this MOD review, we present PomBase's continuing growth and improvement over the last 2 years. We describe these improvements in the context of the qualitative GCBR indicators related to scientific quality, comprehensivity, accelerating science, user stories, and collaborations with other biodata resources. This review also showcases the depth of existing connections both within the biocuration ecosystem and between PomBase and its user community.
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Affiliation(s)
- Kim M Rutherford
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - Manuel Lera-Ramírez
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Valerie Wood
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
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23
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Snedeker J, Davis BEM, Ranjan R, Wooten M, Blundon J, Chen X. Reduced Levels of Lagging Strand Polymerases Shape Stem Cell Chromatin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.591383. [PMID: 38746451 PMCID: PMC11092439 DOI: 10.1101/2024.04.26.591383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Stem cells display asymmetric histone inheritance while non-stem progenitor cells exhibit symmetric patterns in the Drosophila male germline lineage. Here, we report that components involved in lagging strand synthesis, such as DNA polymerase α and δ (Polα and Polδ), have significantly reduced levels in stem cells compared to progenitor cells. Compromising Polα genetically induces the replication-coupled histone incorporation pattern in progenitor cells to be indistinguishable from that in stem cells, which can be recapitulated using a Polα inhibitor in a concentration-dependent manner. Furthermore, stem cell-derived chromatin fibers display a higher degree of old histone recycling by the leading strand compared to progenitor cell-derived chromatin fibers. However, upon reducing Polα levels in progenitor cells, the chromatin fibers now display asymmetric old histone recycling just like GSC-derived fibers. The old versus new histone asymmetry is comparable between stem cells and progenitor cells at both S-phase and M-phase. Together, these results indicate that developmentally programmed expression of key DNA replication components is important to shape stem cell chromatin. Furthermore, manipulating one crucial DNA replication component can induce replication-coupled histone dynamics in non-stem cells in a manner similar to that in stem cells.
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Affiliation(s)
- Jonathan Snedeker
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Brendon E. M. Davis
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Rajesh Ranjan
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Baltimore, MD 21218, USA
| | - Matthew Wooten
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Current address: Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA
| | - Joshua Blundon
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Baltimore, MD 21218, USA
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24
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Hananya N, Koren S, Muir TW. Interrogating epigenetic mechanisms with chemically customized chromatin. Nat Rev Genet 2024; 25:255-271. [PMID: 37985791 PMCID: PMC11176933 DOI: 10.1038/s41576-023-00664-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2023] [Indexed: 11/22/2023]
Abstract
Genetic and genomic techniques have proven incredibly powerful for identifying and studying molecular players implicated in the epigenetic regulation of DNA-templated processes such as transcription. However, achieving a mechanistic understanding of how these molecules interact with chromatin to elicit a functional output is non-trivial, owing to the tremendous complexity of the biochemical networks involved. Advances in protein engineering have enabled the reconstitution of 'designer' chromatin containing customized post-translational modification patterns, which, when used in conjunction with sophisticated biochemical and biophysical methods, allow many mechanistic questions to be addressed. In this Review, we discuss how such tools complement established 'omics' techniques to answer fundamental questions on chromatin regulation, focusing on chromatin mark establishment and protein-chromatin interactions.
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Affiliation(s)
- Nir Hananya
- Department of Chemistry, Princeton University, Princeton, NJ, USA
| | - Shany Koren
- Department of Chemistry, Princeton University, Princeton, NJ, USA
| | - Tom W Muir
- Department of Chemistry, Princeton University, Princeton, NJ, USA.
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25
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Yague-Sanz C. Shaping the chromatin landscape at rRNA and tRNA genes, an emerging new role for RNA polymerase II transcription? Yeast 2024; 41:135-147. [PMID: 38126234 DOI: 10.1002/yea.3921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/17/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
Eukaryotic genes must be condensed into chromatin while remaining accessible to the transcriptional machinery to support gene expression. Among the three eukaryotic RNA polymerases (RNAP), RNAPII is unique, partly because of the C-terminal domain (CTD) of its largest subunit, Rpb1. Rpb1 CTD can be extensively modified during the transcription cycle, allowing for the co-transcriptional recruitment of specific interacting proteins. These include chromatin remodeling factors that control the opening or closing of chromatin. How the CTD-less RNAPI and RNAPIII deal with chromatin at rRNA and tRNA genes is less understood. Here, we review recent advances in our understanding of how the chromatin at tRNA genes and rRNA genes can be remodeled in response to environmental cues in yeast, with a particular focus on the role of local RNAPII transcription in recruiting chromatin remodelers at these loci. In fission yeast, RNAPII transcription at tRNA genes is important to re-establish a chromatin environment permissive to tRNA transcription, which supports growth from stationary phase. In contrast, local RNAPII transcription at rRNA genes correlates with the closing of the chromatin in starvation in budding and fission yeast, suggesting a role in establishing silent chromatin. These opposite roles might support a general model where RNAPII transcription recruits chromatin remodelers to tRNA and rRNA genes to promote the closing and reopening of chromatin in response to the environment.
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Affiliation(s)
- Carlo Yague-Sanz
- Damien Hermand's Laboratory, URPhyM-GEMO, The University of Namur, Namur, Belgium
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26
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Flury V, Groth A. Safeguarding the epigenome through the cell cycle: a multitasking game. Curr Opin Genet Dev 2024; 85:102161. [PMID: 38447236 DOI: 10.1016/j.gde.2024.102161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/29/2024] [Indexed: 03/08/2024]
Abstract
Sustaining cell identity and function across cell division is germane to human development, healthspan, and cancer avoidance. This relies significantly on propagation of chromatin organization between cell generations, as chromatin presents a barrier to cell fate and cell state conversions. Inheritance of chromatin states across the many cell divisions required for development and tissue homeostasis represents a major challenge, especially because chromatin is disrupted to allow passage of the DNA replication fork to synthesize the two daughter strands. This process also leads to a twofold dilution of epigenetic information in histones, which needs to be accurately restored for faithful propagation of chromatin states across cell divisions. Recent research has identified distinct multilayered mechanisms acting to propagate epigenetic information to daughter strands. Here, we summarize key principles of how epigenetic information in parental histones is transferred across DNA replication and how new histones robustly acquire the same information postreplication, representing a core component of epigenetic cell memory.
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Affiliation(s)
- Valentin Flury
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Centre, University of Copenhagen, 2200 Copenhagen, Denmark. https://twitter.com/@ValeFlury
| | - Anja Groth
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, 2200 Copenhagen, Denmark; Biotech Research and Innovation Centre, University of Copenhagen, 2200 Copenhagen, Denmark; Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen, Denmark.
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27
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Uneme Y, Maeda R, Nakayama G, Narita H, Takeda N, Hiramatsu R, Nishihara H, Nakato R, Kanai Y, Araki K, Siomi MC, Yamanaka S. Morc1 reestablishes H3K9me3 heterochromatin on piRNA-targeted transposons in gonocytes. Proc Natl Acad Sci U S A 2024; 121:e2317095121. [PMID: 38502704 PMCID: PMC10990106 DOI: 10.1073/pnas.2317095121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 01/23/2024] [Indexed: 03/21/2024] Open
Abstract
To maintain fertility, male mice re-repress transposable elements (TEs) that were de-silenced in the early gonocytes before their differentiation into spermatogonia. However, the mechanism of TE silencing re-establishment remains unknown. Here, we found that the DNA-binding protein Morc1, in cooperation with the methyltransferase SetDB1, deposits the repressive histone mark H3K9me3 on a large fraction of activated TEs, leading to heterochromatin. Morc1 also triggers DNA methylation, but TEs targeted by Morc1-driven DNA methylation only slightly overlapped with those repressed by Morc1/SetDB1-dependent heterochromatin formation, suggesting that Morc1 silences TEs in two different manners. In contrast, TEs regulated by Morc1 and Miwi2, the nuclear PIWI-family protein, almost overlapped. Miwi2 binds to PIWI-interacting RNAs (piRNAs) that base-pair with TE mRNAs via sequence complementarity, while Morc1 DNA binding is not sequence specific, suggesting that Miwi2 selects its targets, and then, Morc1 acts to repress them with cofactors. A high-ordered mechanism of TE repression in gonocytes has been identified.
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Affiliation(s)
- Yuta Uneme
- Department of Biophysics and Biochemistry, Faculty of Science, The University of Tokyo, Tokyo113-0032, Japan
| | - Ryu Maeda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo113-0032, Japan
| | - Gen Nakayama
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo113-0032, Japan
| | - Haruka Narita
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo113-0032, Japan
| | - Naoki Takeda
- Division of Developmental Genetics, Institute of Resource Development and Analysis, Kumamoto University, Kumamoto860-0811, Japan
| | - Ryuji Hiramatsu
- Department of Veterinary Anatomy, The University of Tokyo, Tokyo113-8657, Japan
| | - Hidenori Nishihara
- Department of Advanced Bioscience, Graduate School of Agriculture, Kindai University, Nara631-8505, Japan
| | - Ryuichiro Nakato
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo113-0032, Japan
| | - Yoshiakira Kanai
- Department of Veterinary Anatomy, The University of Tokyo, Tokyo113-8657, Japan
| | - Kimi Araki
- Division of Developmental Genetics, Institute of Resource Development and Analysis, Kumamoto University, Kumamoto860-0811, Japan
- Faculty of Life Sciences, Center for Metabolic Regulation of Healthy Aging, Kumamoto University, Honjo, Kumamoto860-8556, Japan
| | - Mikiko C. Siomi
- Department of Biophysics and Biochemistry, Faculty of Science, The University of Tokyo, Tokyo113-0032, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo113-0032, Japan
| | - Soichiro Yamanaka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo113-0032, Japan
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28
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Chen P, Li G, Li W. Nucleosome Dynamics Derived at the Single-Molecule Level Bridges Its Structures and Functions. JACS AU 2024; 4:866-876. [PMID: 38559720 PMCID: PMC10976579 DOI: 10.1021/jacsau.3c00658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 04/04/2024]
Abstract
Nucleosome, the building block of chromatin, plays pivotal roles in all DNA-related processes. While cryogenic-electron microscopy (cryo-EM) has significantly advanced our understanding of nucleosome structures, the emerging field of single-molecule force spectroscopy is illuminating their dynamic properties. This technique is crucial for revealing how nucleosome behavior is influenced by chaperones, remodelers, histone variants, and post-translational modifications, particularly in their folding and unfolding mechanisms under tension. Such insights are vital for deciphering the complex interplay in nucleosome assembly and structural regulation, highlighting the nucleosome's versatility in response to DNA activities. In this Perspective, we aim to consolidate the latest advancements in nucleosome dynamics, with a special focus on the revelations brought forth by single-molecule manipulation. Our objective is to highlight the insights gained from studying nucleosome dynamics through this innovative approach, emphasizing the transformative impact of single-molecule manipulation techniques in the field of chromatin research.
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Affiliation(s)
- Ping Chen
- National
Laboratory of Biomacromolecules and Key Laboratory of Epigenetic Regulation
and Intervention, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China
- Department
of Immunology, School of Basic Medical Sciences, Beijing Key Laboratory
for Tumor Invasion and Metastasis, Capital
Medical University, Beijing 100069, P. R. China
| | - Guohong Li
- National
Laboratory of Biomacromolecules and Key Laboratory of Epigenetic Regulation
and Intervention, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China
- University
of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Wei Li
- National
Laboratory of Biomacromolecules and Key Laboratory of Epigenetic Regulation
and Intervention, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China
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29
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Fang Y, Hua X, Shan CM, Toda T, Qiao F, Zhang Z, Jia S. Coordination of histone chaperones for parental histone segregation and epigenetic inheritance. Genes Dev 2024; 38:189-204. [PMID: 38479839 PMCID: PMC10982699 DOI: 10.1101/gad.351278.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/20/2024] [Indexed: 04/02/2024]
Abstract
Chromatin-based epigenetic memory relies on the accurate distribution of parental histone H3-H4 tetramers to newly replicated DNA strands. Mcm2, a subunit of the replicative helicase, and Dpb3/4, subunits of DNA polymerase ε, govern parental histone H3-H4 deposition to the lagging and leading strands, respectively. However, their contribution to epigenetic inheritance remains controversial. Here, using fission yeast heterochromatin inheritance systems that eliminate interference from initiation pathways, we show that a Mcm2 histone binding mutation severely disrupts heterochromatin inheritance, while mutations in Dpb3/4 cause only moderate defects. Surprisingly, simultaneous mutations of Mcm2 and Dpb3/4 stabilize heterochromatin inheritance. eSPAN (enrichment and sequencing of protein-associated nascent DNA) analyses confirmed the conservation of Mcm2 and Dpb3/4 functions in parental histone H3-H4 segregation, with their combined absence showing a more symmetric distribution of parental histone H3-H4 than either single mutation alone. Furthermore, the FACT histone chaperone regulates parental histone transfer to both strands and collaborates with Mcm2 and Dpb3/4 to maintain parental histone H3-H4 density and faithful heterochromatin inheritance. These results underscore the importance of both symmetric distribution of parental histones and their density at daughter strands for epigenetic inheritance and unveil distinctive properties of parental histone chaperones during DNA replication.
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Affiliation(s)
- Yimeng Fang
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Xu Hua
- Institute for Cancer Genetics, Columbia University, New York, New York 10027, USA
- Department of Pediatrics, Columbia University, New York, New York 10027, USA
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, New York 10032, USA
| | - Chun-Min Shan
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Takenori Toda
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Feng Qiao
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, California 92697, USA
| | - Zhiguo Zhang
- Institute for Cancer Genetics, Columbia University, New York, New York 10027, USA;
- Department of Pediatrics, Columbia University, New York, New York 10027, USA
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, New York 10032, USA
| | - Songtao Jia
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA;
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30
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Abasi LS, Elathram N, Movva M, Deep A, Corbett KD, Debelouchina GT. Phosphorylation regulates tau's phase separation behavior and interactions with chromatin. Commun Biol 2024; 7:251. [PMID: 38429335 PMCID: PMC10907630 DOI: 10.1038/s42003-024-05920-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/16/2024] [Indexed: 03/03/2024] Open
Abstract
Tau is a microtubule-associated protein often found in neurofibrillary tangles (NFTs) in the brains of patients with Alzheimer's disease. Beyond this context, mounting evidence suggests that tau localizes into the nucleus, where it may play a role in DNA protection and heterochromatin regulation. The molecular mechanisms behind these observations are currently unclear. Using in vitro biophysical experiments, here we demonstrate that tau can undergo liquid-liquid phase separation (LLPS) with DNA, mononucleosomes, and reconstituted nucleosome arrays under low salt conditions. Low concentrations of tau promote chromatin compaction and protect DNA from digestion. While the material state of samples at physiological salt is dominated by chromatin oligomerization, tau can still associate strongly and reversibly with nucleosome arrays. These properties are driven by tau's strong interactions with linker and nucleosomal DNA. In addition, tau co-localizes into droplets formed by nucleosome arrays and phosphorylated HP1α, a key heterochromatin constituent thought to function through an LLPS mechanism. Importantly, LLPS and chromatin interactions are disrupted by aberrant tau hyperphosphorylation. These biophysical properties suggest that tau may directly impact DNA and chromatin accessibility and that loss of these interactions could contribute to the aberrant nuclear effects seen in tau pathology.
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Affiliation(s)
- Lannah S Abasi
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Nesreen Elathram
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Manasi Movva
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Amar Deep
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Molecular Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Galia T Debelouchina
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA.
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31
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Espinosa-Martínez M, Alcázar-Fabra M, Landeira D. The molecular basis of cell memory in mammals: The epigenetic cycle. SCIENCE ADVANCES 2024; 10:eadl3188. [PMID: 38416817 PMCID: PMC10901381 DOI: 10.1126/sciadv.adl3188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 01/26/2024] [Indexed: 03/01/2024]
Abstract
Cell memory refers to the capacity of cells to maintain their gene expression program once the initiating environmental signal has ceased. This exceptional feature is key during the formation of mammalian organisms, and it is believed to be in part mediated by epigenetic factors that can endorse cells with the landmarks required to maintain transcriptional programs upon cell duplication. Here, we review current literature analyzing the molecular basis of epigenetic memory in mammals, with a focus on the mechanisms by which transcriptionally repressive chromatin modifications such as methylation of DNA and histone H3 are propagated through mitotic cell divisions. The emerging picture suggests that cellular memory is supported by an epigenetic cycle in which reversible activities carried out by epigenetic regulators in coordination with cell cycle transition create a multiphasic system that can accommodate both maintenance of cell identity and cell differentiation in proliferating stem cell populations.
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Affiliation(s)
- Mencía Espinosa-Martínez
- Centre for Genomics and Oncological Research (GENYO), Avenue de la Ilustración 114, 18016 Granada, Spain
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain
| | - María Alcázar-Fabra
- Centre for Genomics and Oncological Research (GENYO), Avenue de la Ilustración 114, 18016 Granada, Spain
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain
| | - David Landeira
- Centre for Genomics and Oncological Research (GENYO), Avenue de la Ilustración 114, 18016 Granada, Spain
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain
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32
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Farahmand Y, Nabiuni M, Vafaei Mastanabad M, Sheibani M, Mahmood BS, Obayes AM, Asadi F, Davallou R. The exo-microRNA (miRNA) signaling pathways in pathogenesis and treatment of stroke diseases: Emphasize on mesenchymal stem cells (MSCs). Cell Biochem Funct 2024; 42:e3917. [PMID: 38379232 DOI: 10.1002/cbf.3917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/07/2023] [Accepted: 12/17/2023] [Indexed: 02/22/2024]
Abstract
A major factor in long-term impairment is stroke. Patients with persistent stroke and severe functional disabilities have few therapy choices. Long noncoding RNAs (lncRNAs) may contribute to the regulation of the pathophysiologic processes of ischemic stroke as shown by altered expression of lncRNAs and microRNA (miRNAs) in blood samples of acute ischemic stroke patients. On the other hand, multipotent mesenchymal stem cells (MSCs) increase neurogenesis, and angiogenesis, dampen neuroinflammation, and boost brain plasticity to improve functional recovery in experimental stroke models. MSCs can be procured from various sources such as the bone marrow, adipose tissue, and peripheral blood. Under the proper circumstances, MSCs can differentiate into a variety of mature cells, including neurons, astrocytes, and oligodendrocytes. Accordingly, the capability of MSCs to exert neuroprotection and also neurogenesis has recently attracted more attention. Nowadays, lncRNAs and miRNAs derived from MSCs have opened new avenues to alleviate stroke symptoms. Accordingly, in this review article, we examined various studies concerning the lncRNAs and miRNAs' role in stroke pathogenesis and delivered an overview of the therapeutic role of MSC-derived miRNAs and lncRNAs in stroke conditions.
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Affiliation(s)
- Yalda Farahmand
- School of Medicine, Terhan University of Medical Sciences, Tehran, Iran
| | - Mohsen Nabiuni
- Neurosurgery Department, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mahsa Vafaei Mastanabad
- Neurosurgery Department, Faculty of Medicine, Qazvin University of Medical Science, Qazvin, Iran
| | - Mehrnaz Sheibani
- Division of Pediatric Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | - Ali Mohammed Obayes
- College of Nursing, National University of Science and Technology, Dhi Qar, Iraq
| | - Fatemeh Asadi
- Department of Genetics, Fars Science and Research Branch, Islamic Azad University, Marvdasht, Iran
- Department of Genetics, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran
| | - Rosa Davallou
- Department of Neurology, Sayyad Shirazi Hospital, Golestan University of Medical Siences, Gorgan, Iran
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33
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Folco H, Xiao H, Wheeler D, Feng H, Bai Y, Grewal SS. The cysteine-rich domain in CENP-A chaperone Scm3HJURP ensures centromere targeting and kinetochore integrity. Nucleic Acids Res 2024; 52:1688-1701. [PMID: 38084929 PMCID: PMC10899784 DOI: 10.1093/nar/gkad1182] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 11/20/2023] [Accepted: 11/28/2023] [Indexed: 02/29/2024] Open
Abstract
Centromeric chromatin plays a crucial role in kinetochore assembly and chromosome segregation. Centromeres are specified through the loading of the histone H3 variant CENP-A by the conserved chaperone Scm3/HJURP. The N-terminus of Scm3/HJURP interacts with CENP-A, while the C-terminus facilitates centromere localization by interacting with the Mis18 holocomplex via a small domain, called the Mis16-binding domain (Mis16-BD) in fission yeast. Fungal Scm3 proteins contain an additional conserved cysteine-rich domain (CYS) of unknown function. Here, we find that CYS binds zinc in vitro and is essential for the localization and function of fission yeast Scm3. Disrupting CYS by deletion or introduction of point mutations within its zinc-binding motif prevents Scm3 centromere localization and compromises kinetochore integrity. Interestingly, CYS alone can localize to the centromere, albeit weakly, but its targeting is greatly enhanced when combined with Mis16-BD. Expressing a truncated protein containing both Mis16-BD and CYS, but lacking the CENP-A binding domain, causes toxicity and is accompanied by considerable chromosome missegregation and kinetochore loss. These effects can be mitigated by mutating the CYS zinc-binding motif. Collectively, our findings establish the essential role of the cysteine-rich domain in fungal Scm3 proteins and provide valuable insights into the mechanism of Scm3 centromere targeting.
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Affiliation(s)
- H Diego Folco
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hua Xiao
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Wheeler
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hanqiao Feng
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yawen Bai
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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34
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Muhammad A, Sarkadi Z, van Emden T, Mazumder A, Capella M, Fekete G, Sreechakram VNS, Al-Sady B, Papp B, Barrales RR, Braun S. A systematic quantitative approach comprehensively defines domain-specific functional pathways linked to Schizosaccharomyces pombe heterochromatin regulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.579970. [PMID: 38405799 PMCID: PMC10888830 DOI: 10.1101/2024.02.13.579970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Heterochromatin plays a critical role in regulating gene expression and maintaining genome integrity. While structural and enzymatic components have been linked to heterochromatin establishment, a comprehensive view of the underlying pathways at diverse heterochromatin domains remains elusive. Here, we developed a systematic approach to identify factors involved in heterochromatin silencing at pericentromeres, subtelomeres, and the silent mating type locus in Schizosaccharomyces pombe. Using quantitative measures, iterative genetic screening, and domain-specific heterochromatin reporters, we identified 369 mutants with different degrees of reduced or enhanced silencing. As expected, mutations in the core heterochromatin machinery globally decreased silencing. However, most other mutants exhibited distinct qualitative and quantitative profiles that indicate domain-specific functions. For example, decreased mating type silencing was linked to mutations in heterochromatin maintenance genes, while compromised subtelomere silencing was associated with metabolic pathways. Furthermore, similar phenotypic profiles revealed shared functions for subunits within complexes. We also discovered that the uncharacterized protein Dhm2 plays a crucial role in maintaining constitutive and facultative heterochromatin, while its absence caused phenotypes akin to DNA replication-deficient mutants. Collectively, our systematic approach unveiled a landscape of domain-specific heterochromatin regulators controlling distinct states and identified Dhm2 as a previously unknown factor linked to heterochromatin inheritance and replication fidelity.
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Affiliation(s)
- Abubakar Muhammad
- Institute for Genetics, Justus-Liebig-University Giessen, Giessen, Germany
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
- International Max Planck Research School for Molecular and Cellular Life Sciences, Planegg-Martinsried, Germany
| | - Zsuzsa Sarkadi
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
- Synthetic and Systems Biology Unit, Institute of Biochemistry, HUN-REN Biological Research Centre, Szeged, Hungary
- HCEMM-BRC Metabolic Systems Biology Lab, Szeged, Hungary
| | - Thomas van Emden
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
- International Max Planck Research School for Molecular and Cellular Life Sciences, Planegg-Martinsried, Germany
| | - Agnisrota Mazumder
- Institute for Genetics, Justus-Liebig-University Giessen, Giessen, Germany
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
| | - Matias Capella
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
- Present address: Instituto de Agrobiotecnología del Litoral, CONICET, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Gergely Fekete
- Synthetic and Systems Biology Unit, Institute of Biochemistry, HUN-REN Biological Research Centre, Szeged, Hungary
- HCEMM-BRC Metabolic Systems Biology Lab, Szeged, Hungary
| | - Vishnu N Suma Sreechakram
- Institute for Genetics, Justus-Liebig-University Giessen, Giessen, Germany
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
| | - Bassem Al-Sady
- Department of Microbiology & Immunology, George Williams Hooper Foundation, University of California San Francisco, San Francisco, California, United States of America
| | - Balázs Papp
- Synthetic and Systems Biology Unit, Institute of Biochemistry, HUN-REN Biological Research Centre, Szeged, Hungary
- HCEMM-BRC Metabolic Systems Biology Lab, Szeged, Hungary
| | - Ramón Ramos Barrales
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
- Present address: Centro Andaluz de Biología del Desarrollo (CABD), Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Seville, Spain
| | - Sigurd Braun
- Institute for Genetics, Justus-Liebig-University Giessen, Giessen, Germany
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
- International Max Planck Research School for Molecular and Cellular Life Sciences, Planegg-Martinsried, Germany
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35
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Nathanailidou P, Dhakshnamoorthy J, Xiao H, Zofall M, Holla S, O’Neill M, Andresson T, Wheeler D, Grewal SIS. Specialized replication of heterochromatin domains ensures self-templated chromatin assembly and epigenetic inheritance. Proc Natl Acad Sci U S A 2024; 121:e2315596121. [PMID: 38285941 PMCID: PMC10861883 DOI: 10.1073/pnas.2315596121] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 12/21/2023] [Indexed: 01/31/2024] Open
Abstract
Heterochromatin, defined by histone H3 lysine 9 methylation (H3K9me), spreads across large domains and can be epigenetically inherited in a self-propagating manner. Heterochromatin propagation depends upon a read-write mechanism, where the Clr4/Suv39h methyltransferase binds to preexisting trimethylated H3K9 (H3K9me3) and further deposits H3K9me. How the parental methylated histone template is preserved during DNA replication is not well understood. Here, we demonstrate using Schizosaccharomyces pombe that heterochromatic regions are specialized replication domains demarcated by their surrounding boundary elements. DNA replication throughout these domains is distinguished by an abundance of replisome components and is coordinated by Swi6/HP1. Although mutations in the replicative helicase subunit Mcm2 that affect histone binding impede the maintenance of a heterochromatin domain at an artificially targeted ectopic site, they have only a modest impact on heterochromatin propagation via the read-write mechanism at an endogenous site. Instead, our findings suggest a crucial role for the replication factor Mcl1 in retaining parental histones and promoting heterochromatin propagation via a mechanism involving the histone chaperone FACT. Engagement of FACT with heterochromatin requires boundary elements, which position the heterochromatic domain at the nuclear peripheral subdomain enriched for heterochromatin factors. Our findings highlight the importance of replisome components and boundary elements in creating a specialized environment for the retention of parental methylated histones, which facilitates epigenetic inheritance of heterochromatin.
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Affiliation(s)
- Patroula Nathanailidou
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD20892
| | - Jothy Dhakshnamoorthy
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD20892
| | - Hua Xiao
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD20892
| | - Martin Zofall
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD20892
| | - Sahana Holla
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD20892
| | - Maura O’Neill
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD21701
| | - Thorkell Andresson
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD21701
| | - David Wheeler
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD20892
| | - Shiv I. S. Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD20892
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36
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Ingersoll S, Trouth A, Luo X, Espinoza A, Wen J, Tucker J, Astatike K, Phiel CJ, Kutateladze TG, Wu TP, Ramachandran S, Ren X. Sparse CBX2 nucleates many Polycomb proteins to promote facultative heterochromatinization of Polycomb target genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.05.578969. [PMID: 38370615 PMCID: PMC10871256 DOI: 10.1101/2024.02.05.578969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Facultative heterochromatinization of genomic regulators by Polycomb repressive complex (PRC) 1 and 2 is essential in development and differentiation; however, the underlying molecular mechanisms remain obscure. Using genetic engineering, molecular approaches, and live-cell single-molecule imaging, we quantify the number of proteins within condensates formed through liquid-liquid phase separation (LLPS) and find that in mouse embryonic stem cells (mESCs), approximately 3 CBX2 proteins nucleate many PRC1 and PRC2 subunits to form one non-stoichiometric condensate. We demonstrate that sparse CBX2 prevents Polycomb proteins from migrating to constitutive heterochromatin, demarcates the spatial boundaries of facultative heterochromatin, controls the deposition of H3K27me3, regulates transcription, and impacts cellular differentiation. Furthermore, we show that LLPS of CBX2 is required for the demarcation and deposition of H3K27me3 and is essential for cellular differentiation. Our findings uncover new functional roles of LLPS in the formation of facultative heterochromatin and unravel a new mechanism by which low-abundant proteins nucleate many other proteins to form compartments that enable them to execute their functions.
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Affiliation(s)
- Steven Ingersoll
- Department of Chemistry, University of Colorado Denver, Denver, CO 80217-3364, USA
| | - Abby Trouth
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Xinlong Luo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Axel Espinoza
- Department of Integrative Biology, University of Colorado Denver, CO 80217-3364, USA
| | - Joey Wen
- Department of Chemistry, University of Colorado Denver, Denver, CO 80217-3364, USA
| | - Joseph Tucker
- Department of Integrative Biology, University of Colorado Denver, CO 80217-3364, USA
| | - Kalkidan Astatike
- Department of Chemistry, University of Colorado Denver, Denver, CO 80217-3364, USA
| | - Christopher J. Phiel
- Department of Integrative Biology, University of Colorado Denver, CO 80217-3364, USA
| | - Tatiana G. Kutateladze
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Tao P. Wu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Srinivas Ramachandran
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, USA
| | - Xiaojun Ren
- Department of Chemistry, University of Colorado Denver, Denver, CO 80217-3364, USA
- Department of Integrative Biology, University of Colorado Denver, CO 80217-3364, USA
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37
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Schulz EG. BREACHing new grounds in fragile X syndrome: Trinucleotide expansion linked to genome-wide heterochromatin domains and genome misfolding. Mol Cell 2024; 84:413-414. [PMID: 38307002 DOI: 10.1016/j.molcel.2023.12.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 12/21/2023] [Accepted: 12/21/2023] [Indexed: 02/04/2024]
Abstract
In a recent study in Cell, Malachowski et al.1 show that the trinucleotide expansion in the FMR1 gene underlying fragile X syndrome triggers formation of large heterochromatin domains across the genome, resulting in the repression of synaptic genes housed within these domains.
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Affiliation(s)
- Edda G Schulz
- Max Planck Institute for Molecular Genetics, Berlin, Germany
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38
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Wang H, Su M, Xing J, Zhou J, Wang J, Chen L, Dong H, Xue W, Liu Y, Wu Q, Zhang Y. HHCDB: a database of human heterochromatin regions. Nucleic Acids Res 2024; 52:D145-D153. [PMID: 37897357 PMCID: PMC10767959 DOI: 10.1093/nar/gkad954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/08/2023] [Accepted: 10/12/2023] [Indexed: 10/30/2023] Open
Abstract
Heterochromatin plays essential roles in eukaryotic genomes, such as regulating genes, maintaining genome integrity and silencing repetitive DNA elements. Identifying genome-wide heterochromatin regions is crucial for studying transcriptional regulation. We propose the Human Heterochromatin Chromatin Database (HHCDB) for archiving heterochromatin regions defined by specific or combined histone modifications (H3K27me3, H3K9me2, H3K9me3) according to a unified pipeline. 42 839 743 heterochromatin regions were identified from 578 samples derived from 241 cell-types/cell lines and 92 tissue types. Genomic information is provided in HHCDB, including chromatin location, gene structure, transcripts, distance from transcription start site, neighboring genes, CpG islands, transposable elements, 3D genomic structure and functional annotations. Furthermore, transcriptome data from 73 single cells were analyzed and integrated to explore cell type-specific heterochromatin-related genes. HHCDB affords rich visualization through the UCSC Genome Browser and our self-developed tools. We have also developed a specialized online analysis platform to mine differential heterochromatin regions in cancers. We performed several analyses to explore the function of cancer-specific heterochromatin-related genes, including clinical feature analysis, immune cell infiltration analysis and the construction of drug-target networks. HHCDB is a valuable resource for studying epigenetic regulation, 3D genomics and heterochromatin regulation in development and disease. HHCDB is freely accessible at http://hhcdb.edbc.org/.
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Affiliation(s)
- Hongli Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Mu Su
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Jie Xing
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Jie Zhou
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Jinzhang Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Long Chen
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Haomin Dong
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Wenhui Xue
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Yubo Liu
- The Leicester International Institute, Dalian University of Technology, Dalian 116000, China
| | - Qiong Wu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Yan Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
- College of Pathology, Qiqihar Medical University, Qiqihar 161042, China
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39
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Abasi LS, Elathram N, Movva M, Deep A, Corbett KD, Debelouchina GT. Phosphorylation regulates tau's phase separation behavior and interactions with chromatin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.21.572911. [PMID: 38187700 PMCID: PMC10769318 DOI: 10.1101/2023.12.21.572911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Tau is a microtubule-associated protein often found in neurofibrillary tangles (NFTs) in the brains of patients with Alzheimer's disease (AD). Beyond this context, mounting evidence suggests that tau localizes into the nucleus, where it may play a role in DNA protection and heterochromatin regulation. Models of tau depletion or pathology show loss of genetically silent heterochromatin, aberrant expression of heterochromatic genes, and transposable element activation. The molecular mechanisms behind these observations are currently unclear. Using in vitro biophysical experiments, here we demonstrate that tau can undergo liquid-liquid phase separation (LLPS) with DNA, mononucleosomes, and reconstituted nucleosome arrays under low salt conditions. Low concentrations of tau promote chromatin compaction and protect DNA from digestion. While the material state of samples at physiological salt is dominated by chromatin oligomerization, tau can still associate strongly and reversibly with nucleosome arrays. These properties are driven by tau's strong interactions with linker and nucleosomal DNA, while magic angle spinning (MAS) solid-state NMR experiments show that tau binding does not drastically alter nucleosome structure and dynamics. In addition, tau co-localizes into droplets formed by nucleosome arrays and phosphorylated HP1α, a key heterochromatin constituent thought to function through an LLPS mechanism. Importantly, LLPS and chromatin interactions are disrupted by aberrant tau hyperphosphorylation. These biophysical properties suggest that tau may directly impact DNA and chromatin accessibility and that loss of these interactions could contribute to the aberrant nuclear effects seen in tau pathology.
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Affiliation(s)
- Lannah S. Abasi
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nesreen Elathram
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Manasi Movva
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Amar Deep
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kevin D. Corbett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Galia T. Debelouchina
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
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40
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Han MH, Issagulova D, Park M. Interplay between epigenome and 3D chromatin structure. BMB Rep 2023; 56:633-644. [PMID: 38052424 PMCID: PMC10761748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/28/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023] Open
Abstract
Epigenetic mechanisms, primarily mediated through histone and DNA modifications, play a pivotal role in orchestrating the functional identity of a cell and its response to environmental cues. Similarly, the spatial arrangement of chromatin within the threedimensional (3D) nucleus has been recognized as a significant factor influencing genomic function. Investigating the relationship between epigenetic regulation and 3D chromatin structure has revealed correlation and causality between these processes, from the global alignment of average chromatin structure with chromatin marks to the nuanced correlations at smaller scales. This review aims to dissect the biological significance and the interplay between the epigenome and 3D chromatin structure, while also exploring the underlying molecular mechanisms. By synthesizing insights from both experimental and modeling perspectives, we seek to provide a comprehensive understanding of cellular functions. [BMB Reports 2023; 56(12): 633-644].
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Affiliation(s)
- Man-Hyuk Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Dariya Issagulova
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Minhee Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea; Graduate School of Engineering Biology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141; KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141; KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
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41
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Solodovnikov AA, Lavrov SA, Shatskikh AS, Gvozdev VA. Effects of Chromatin Structure Modifiers on the trans-Acting Heterochromatin Position Effect in Drosophila melanogaster. DOKL BIOCHEM BIOPHYS 2023; 513:S75-S81. [PMID: 38379078 DOI: 10.1134/s160767292470073x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 12/30/2023] [Accepted: 01/02/2024] [Indexed: 02/22/2024]
Abstract
The heterochromatin position effect is manifested in the inactivation of euchromatin genes transferred to heterochromatin. In chromosomal rearrangements, genes located near the new eu-heterochromatin boundary in the rearrangement (cis-inactivation) and, in rare cases, genes of a region of the normal chromosome homologous to the region of the eu-heterochromatin boundary of the chromosome with the rearrangement (trans-inactivation) are subject to inactivation. The In(2)A4 inversion is able to trans-inactivate the UAS-eGFP reporter gene located on the normal chromosome. We knockdown a number of chromatin proteins using temperature-controlled RNA interference and investigated the effect of knockdown on trans-inactivation of the reporter. We found suppression of trans-inactivation by knockdowns of Su(var)2-HP2, a protein that binds to the key heterochromatin protein HP1a, SAYP, a subunit of the chromatin remodelling complex, and Eggless histone methyltransferase (SETDB1), which introduces a H3K9me3 histone mark, recognized by the HP1a protein. The method of studying the effects of gene knockdown on heterochromatin position effects presented in this work is of independent methodological interest.
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Affiliation(s)
| | - S A Lavrov
- National Research Center "Kurchatov Institute", Moscow, Russia.
| | - A S Shatskikh
- National Research Center "Kurchatov Institute", Moscow, Russia
| | - V A Gvozdev
- National Research Center "Kurchatov Institute", Moscow, Russia
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42
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Seman M, Levashkevich A, Larkin A, Huang F, Ragunathan K. Uncoupling the distinct functions of HP1 proteins during heterochromatin establishment and maintenance. Cell Rep 2023; 42:113428. [PMID: 37952152 DOI: 10.1016/j.celrep.2023.113428] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 09/28/2023] [Accepted: 10/26/2023] [Indexed: 11/14/2023] Open
Abstract
H3K9 methylation (H3K9me) marks transcriptionally silent genomic regions called heterochromatin. HP1 proteins are required to establish and maintain heterochromatin. HP1 proteins bind to H3K9me, recruit factors that promote heterochromatin formation, and oligomerize to form phase-separated condensates. We do not understand how these different HP1 properties are involved in establishing and maintaining transcriptional silencing. Here, we demonstrate that the S. pombe HP1 homolog, Swi6, can be completely bypassed to establish silencing at ectopic and endogenous loci when an H3K4 methyltransferase, Set1, and an H3K14 acetyltransferase, Mst2, are deleted. Deleting Set1 and Mst2 enhances Clr4 enzymatic activity, leading to higher H3K9me levels and spreading. In contrast, Swi6 and its capacity to oligomerize were indispensable during epigenetic maintenance. Our results demonstrate the role of HP1 proteins in regulating histone modification crosstalk during establishment and identify a genetically separable function in maintaining epigenetic memory.
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Affiliation(s)
- Melissa Seman
- Department of Biology, Brandeis University, Waltham, MA 02451, USA
| | | | - Ajay Larkin
- Department of Biology, Brandeis University, Waltham, MA 02451, USA
| | - Fengting Huang
- Department of Biology, Brandeis University, Waltham, MA 02451, USA
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43
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Elathram N, Ackermann BE, Clark ET, Dunn SR, Debelouchina GT. Phosphorylated HP1α-Nucleosome Interactions in Phase Separated Environments. J Am Chem Soc 2023; 145:23994-24004. [PMID: 37870432 PMCID: PMC10636758 DOI: 10.1021/jacs.3c06481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 10/03/2023] [Accepted: 10/05/2023] [Indexed: 10/24/2023]
Abstract
In the nucleus, transcriptionally silent genes are sequestered into heterochromatin compartments comprising nucleosomes decorated with histone H3 Lys9 trimethylation and a protein called HP1α. This protein can form liquid-liquid droplets in vitro and potentially organize heterochromatin through a phase separation mechanism that is promoted by phosphorylation. Elucidating the molecular interactions that drive HP1α phase separation and its consequences on nucleosome structure and dynamics has been challenging due to the viscous and heterogeneous nature of such assemblies. Here, we tackle this problem by a combination of solution and solid-state NMR spectroscopy, which allows us to dissect the interactions of phosphorylated HP1α with nucleosomes in the context of phase separation. Our experiments indicate that phosphorylated human HP1α does not cause any major rearrangements to the nucleosome core, in contrast to the yeast homologue Swi6. Instead, HP1α interacts specifically with the methylated H3 tails and slows the dynamics of the H4 tails. Our results shed light on how phosphorylated HP1α proteins may regulate the heterochromatin landscape, while our approach provides an atomic resolution view of a heterogeneous and dynamic biological system regulated by a complex network of interactions and post-translational modifications.
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Affiliation(s)
- Nesreen Elathram
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Bryce E. Ackermann
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Evan T. Clark
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Shelby R. Dunn
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Galia T. Debelouchina
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
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44
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Hamali B, Amine AAA, Al-Sady B. Regulation of the heterochromatin spreading reaction by trans-acting factors. Open Biol 2023; 13:230271. [PMID: 37935357 PMCID: PMC10645111 DOI: 10.1098/rsob.230271] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 10/03/2023] [Indexed: 11/09/2023] Open
Abstract
Heterochromatin is a gene-repressive protein-nucleic acid ultrastructure that is initially nucleated by DNA sequences. However, following nucleation, heterochromatin can then propagate along the chromatin template in a sequence-independent manner in a reaction termed spreading. At the heart of this process are enzymes that deposit chemical information on chromatin, which attracts the factors that execute chromatin compaction and transcriptional or co/post-transcriptional gene silencing. Given that these enzymes deposit guiding chemical information on chromatin they are commonly termed 'writers'. While the processes of nucleation and central actions of writers have been extensively studied and reviewed, less is understood about how the spreading process is regulated. We discuss how the chromatin substrate is prepared for heterochromatic spreading, and how trans-acting factors beyond writer enzymes regulate it. We examine mechanisms by which trans-acting factors in Suv39, PRC2, SETDB1 and SIR writer systems regulate spreading of the respective heterochromatic marks across chromatin. While these systems are in some cases evolutionarily and mechanistically quite distant, common mechanisms emerge which these trans-acting factors exploit to tune the spreading reaction.
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Affiliation(s)
- Bulut Hamali
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
- The G. W. Hooper Foundation, San Francisco, CA 94143, USA
- College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Ahmed A A Amine
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
- The G. W. Hooper Foundation, San Francisco, CA 94143, USA
| | - Bassem Al-Sady
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
- The G. W. Hooper Foundation, San Francisco, CA 94143, USA
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45
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Murphy PJ, Berger F. The chromatin source-sink hypothesis: a shared mode of chromatin-mediated regulations. Development 2023; 150:dev201989. [PMID: 38771301 PMCID: PMC10629678 DOI: 10.1242/dev.201989] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 09/12/2023] [Indexed: 11/05/2023]
Abstract
We propose that several chromatin-mediated regulatory processes are dominated by source-sink relationships in which factors operate as 'sources' to produce or provide a resource and compete with each other to occupy separate 'sinks'. In this model, large portions of genomic DNA operate as 'sinks', which are filled by 'sources', such as available histone variants, covalent modifications to histones, the readers of these modifications and non-coding RNAs. Competing occupation for the sinks by different sources leads to distinct states of genomic equilibrium in differentiated cells. During dynamic developmental events, such as sexual reproduction, we propose that dramatic and rapid reconfiguration of source-sink relationships modifies chromatin states. We envision that re-routing of sources could occur by altering the dimensions of the sink, by reconfiguration of existing sink occupation or by varying the size of the source, providing a central mechanism to explain a plethora of epigenetic phenomena, which contribute to phenotypic variegation, zygotic genome activation and nucleolar dominance.
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Affiliation(s)
- Patrick J. Murphy
- University of Rochester, Department of Biomedical Genetics and Department of Biology, 601 Elmwood Ave., Rochester NY 14620, USA
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter; Dr. Bohr-Gasse 3, 1030 Vienna, Austria
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Seman M, Levashkevich A, Larkin A, Huang F, Ragunathan K. Uncoupling the distinct functions of HP1 proteins during heterochromatin establishment and maintenance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.30.538869. [PMID: 37961629 PMCID: PMC10634687 DOI: 10.1101/2023.04.30.538869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
H3K9 methylation (H3K9me) marks transcriptionally silent genomic regions called heterochromatin. HP1 proteins are required to establish and maintain heterochromatin. HP1 proteins bind to H3K9me, recruit factors that promote heterochromatin formation, and oligomerize to form phase-separated condensates. We do not understand how HP1 protein binding to heterochromatin establishes and maintains transcriptional silencing. Here, we demonstrate that the S.pombe HP1 homolog, Swi6, can be completely bypassed to establish silencing at ectopic and endogenous loci when an H3K4 methyltransferase, Set1 and an H3K14 acetyltransferase, Mst2 are deleted. Deleting Set1 and Mst2 enhances Clr4 enzymatic activity, leading to higher H3K9me levels and spreading. In contrast, Swi6 and its capacity to oligomerize were indispensable during epigenetic maintenance. Our results demonstrate the role of HP1 proteins in regulating histone modification crosstalk during establishment and identifies a genetically separable function in maintaining epigenetic memory.
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Affiliation(s)
- Melissa Seman
- Department of Biology, Brandeis University, Waltham, MA 02451 USA
| | | | - Ajay Larkin
- Department of Biology, Brandeis University, Waltham, MA 02451 USA
| | - Fengting Huang
- Department of Biology, Brandeis University, Waltham, MA 02451 USA
| | - Kaushik Ragunathan
- Department of Biology, Brandeis University, Waltham, MA 02451 USA
- Lead Contact
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Rieger I, Weintraub G, Lev I, Goldstein K, Bar-Zvi D, Anava S, Gingold H, Shaham S, Rechavi O. Nucleus-independent transgenerational small RNA inheritance in Caenorhabditis elegans. SCIENCE ADVANCES 2023; 9:eadj8618. [PMID: 37878696 PMCID: PMC10599617 DOI: 10.1126/sciadv.adj8618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 09/20/2023] [Indexed: 10/27/2023]
Abstract
In Caenorhabditis elegans worms, epigenetic information transmits transgenerationally. Still, it is unknown whether the effects transfer to the next generation inside or outside of the nucleus. Here, we use the tractability of gene-specific double-stranded RNA-induced silencing to demonstrate that RNA interference can be inherited independently of any nuclear factors via mothers that are genetically engineered to transmit only their ooplasm but not the oocytes' nuclei to the next generation. We characterize the mechanisms and, using RNA sequencing, chimeric worms, and sequence polymorphism between different isolates, identify endogenous small RNAs which, similarly to exogenous siRNAs, are inherited in a nucleus-independent manner. From a historical perspective, these results might be regarded as partial vindication of discredited cytoplasmic inheritance theories from the 19th century, such as Darwin's "pangenesis" theory.
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Affiliation(s)
- Itai Rieger
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Guy Weintraub
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Itamar Lev
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Kesem Goldstein
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Dana Bar-Zvi
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Sarit Anava
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Hila Gingold
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY, USA
| | - Oded Rechavi
- Department of Neurobiology, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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Sinha J, Nickels JF, Thurm AR, Ludwig CH, Archibald BN, Hinks MM, Wan J, Fang D, Bintu L. The H3.3 K36M oncohistone disrupts the establishment of epigenetic memory through loss of DNA methylation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.13.562147. [PMID: 37873347 PMCID: PMC10592807 DOI: 10.1101/2023.10.13.562147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Histone H3.3 is frequently mutated in cancers, with the lysine 36 to methionine mutation (K36M) being a hallmark of chondroblastomas. While it is known that H3.3K36M changes the cellular epigenetic landscape, it remains unclear how it affects the dynamics of gene expression. Here, we use a synthetic reporter to measure the effect of H3.3K36M on silencing and epigenetic memory after recruitment of KRAB: a member of the largest class of human repressors, commonly used in synthetic biology, and associated with H3K9me3. We find that H3.3K36M, which decreases H3K36 methylation, leads to a decrease in epigenetic memory and promoter methylation weeks after KRAB release. We propose a new model for establishment and maintenance of epigenetic memory, where H3K36 methylation is necessary to convert H3K9me3 domains into DNA methylation for stable epigenetic memory. Our quantitative model can inform oncogenic mechanisms and guide development of epigenetic editing tools.
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Affiliation(s)
- Joydeb Sinha
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jan F. Nickels
- Niels Bohr Institute, University of Copenhagen, Copenhagen 2100, Denmark
| | - Abby R. Thurm
- Biophysics Program, Stanford University, Stanford, CA 94305, USA
| | - Connor H. Ludwig
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Bella N. Archibald
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Michaela M. Hinks
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Jun Wan
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Dong Fang
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Lacramioara Bintu
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
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