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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:gkae664. [PMID: 39106166 DOI: 10.1093/nar/gkae664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [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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2
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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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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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Yeom S, Oh J, Kim D, Lee JS. The 80 th Threonine Residue of Histone H3 Is Important for Maintaining HM Silencing in Saccharomyces cerevisiae. J Microbiol Biotechnol 2024; 34:39-46. [PMID: 37957109 PMCID: PMC10840469 DOI: 10.4014/jmb.2310.10031] [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: 10/23/2023] [Revised: 11/02/2023] [Accepted: 11/08/2023] [Indexed: 11/15/2023]
Abstract
Gene expression in eukaryotic cells is intricately regulated by chromatin structure and various factors, including histone proteins. In Saccharomyces cerevisiae, transcriptionally silenced regions, such as telomeres and homothallic mating (HM) loci, are essential for genome stability and proper cellular function. We firstly observed the defective HM silencing in alanine substitution mutant of 80th threonine residue of histone H3 (H3T80A). To identify which properties in the H3T80 residue are important for the HM silencing, we created several substitution mutants of H3T80 residue by considering the changed states of charge, polarity, and structural similarity. This study reveals that the structural similarity of the 80th position of H3 to the threonine residue, not the polarity and charges, is the most important thing for the transcriptional silencing in the HM loci.
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Affiliation(s)
- Soojin Yeom
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
- Institute of Life Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Junsoo Oh
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
- Institute of Life Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Donghyun Kim
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Jung-Shin Lee
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
- Institute of Life Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea
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Bruno S, Schlaeger TM, Del Vecchio D. Epigenetic OCT4 regulatory network: stochastic analysis of cellular reprogramming. NPJ Syst Biol Appl 2024; 10:3. [PMID: 38184707 PMCID: PMC10771499 DOI: 10.1038/s41540-023-00326-0] [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: 07/12/2023] [Accepted: 12/08/2023] [Indexed: 01/08/2024] Open
Abstract
Experimental studies have shown that chromatin modifiers have a critical effect on cellular reprogramming, i.e., the conversion of differentiated cells to pluripotent stem cells. Here, we develop a model of the OCT4 gene regulatory network that includes genes expressing chromatin modifiers TET1 and JMJD2, and the chromatin modification circuit on which these modifiers act. We employ this model to compare three reprogramming approaches that have been considered in the literature with respect to reprogramming efficiency and latency variability. These approaches are overexpression of OCT4 alone, overexpression of OCT4 with TET1, and overexpression of OCT4 with JMJD2. Our results show more efficient and less variable reprogramming when also JMJD2 and TET1 are overexpressed, consistent with previous experimental data. Nevertheless, TET1 overexpression can lead to more efficient reprogramming compared to JMJD2 overexpression. This is the case when the recruitment of DNA methylation by H3K9me3 is weak and the methyl-CpG-binding domain (MBD) proteins are sufficiently scarce such that they do not hamper TET1 binding to methylated DNA. The model that we developed provides a mechanistic understanding of existing experimental results and is also a tool for designing optimized reprogramming approaches that combine overexpression of cell-fate specific transcription factors (TFs) with targeted recruitment of epigenetic modifiers.
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Affiliation(s)
- Simone Bruno
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Thorsten M Schlaeger
- Boston Children's Hospital Stem Cell Program, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Domitilla Del Vecchio
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
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6
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Ghanbari M, Khosroshahi NS, Alamdar M, Abdi A, Aghazadeh A, Feizi MAH, Haghi M. An Updated Review on the Significance of DNA and Protein Methyltransferases and De-methylases in Human Diseases: From Molecular Mechanism to Novel Therapeutic Approaches. Curr Med Chem 2024; 31:3550-3587. [PMID: 37287285 DOI: 10.2174/0929867330666230607124803] [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: 12/06/2022] [Revised: 05/05/2023] [Accepted: 05/09/2023] [Indexed: 06/09/2023]
Abstract
Epigenetic mechanisms are crucial in regulating gene expression. These mechanisms include DNA methylation and histone modifications, like methylation, acetylation, and phosphorylation. DNA methylation is associated with gene expression suppression; however, histone methylation can stimulate or repress gene expression depending on the methylation pattern of lysine or arginine residues on histones. These modifications are key factors in mediating the environmental effect on gene expression regulation. Therefore, their aberrant activity is associated with the development of various diseases. The current study aimed to review the significance of DNA and histone methyltransferases and demethylases in developing various conditions, like cardiovascular diseases, myopathies, diabetes, obesity, osteoporosis, cancer, aging, and central nervous system conditions. A better understanding of the epigenetic roles in developing diseases can pave the way for developing novel therapeutic approaches for affected patients.
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Affiliation(s)
- Mohammad Ghanbari
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - Negin Sadi Khosroshahi
- Department of Biology, Faculty of Basic Sciences, Azarbaijan Shahid Madani University, Tabriz, Iran
| | - Maryam Alamdar
- Department of Genetics Sciences, Faculty of Advanced Sciences and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Adel Abdi
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - Aida Aghazadeh
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | | | - Mehdi Haghi
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
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Xu K, Li J, Li WX. Simulation of STAT and HP1 interaction by molecular docking. Cell Signal 2023; 112:110925. [PMID: 37839545 DOI: 10.1016/j.cellsig.2023.110925] [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: 07/27/2023] [Revised: 10/06/2023] [Accepted: 10/11/2023] [Indexed: 10/17/2023]
Abstract
Heterochromatin Protein 1 (HP1) is a major component of heterochromatin. Multiple proteins have been shown to interact with HP1 with the HP1-binding motif PxVxL/I, thereby affecting heterochromatin stability. The HP1-interacting proteins include the signal transducer and activator of transcription (STAT) protein, which can be regulated by phosphorylation on a tyrosine around amino acid 700 in the carboxyl terminus. Previous research has shown that unphosphorylated STAT (uSTAT) binds to HP1 via a PxVxI HP1-binding motif and maintains the stability of heterochromatin, while phosphorylated STAT (pSTAT) dissociates from HP1, resulting in heterochromatin disruption. To understand the theoretical basis of the biochemical observations, we employed computational modeling to investigate STAT-HP1 binding configurations and the effect of STAT phosphorylation on their interaction. Using STAT3 and HP1α protein structures for molecular docking and thermodynamic calculations, our computations predict that uSTAT homodimers have a higher affinity for HP1 and a lower affinity for DNA than pSTAT homodimers, and that phosphorylation induces a conformational change in STAT, shifting its binding preference from HP1 to DNA. The results of our modeling studies support the idea that phosphorylation drives STAT from HP1-binding to DNA-binding, suggesting a potential role for uSTAT in both maintaining and initiating heterochromatin formation.
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Affiliation(s)
- Kangxin Xu
- Department of Medicine, University of California San Diego, USA
| | - Jinghong Li
- Department of Medicine, University of California San Diego, USA
| | - Willis X Li
- Department of Medicine, University of California San Diego, USA.
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Chen Y, Huang Z, Peng Q, Wang Y. Single Genomic Loci Labeling and Manipulation Using SIMBA System. Curr Protoc 2023; 3:e947. [PMID: 38054948 DOI: 10.1002/cpz1.947] [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: 12/07/2023]
Abstract
The SIMBA (Simultaneous Imaging and Manipulation of genomic loci by Biomolecular Assemblies) system is an innovative CRISPR-based imaging technique that leverages dCas9-SunTag and FRB-mCherry-HP1α, with scFv-FKBP acting as a bridge. This powerful system enables simultaneous visualization and manipulation of genomic loci. The dCas9-SunTag fusion protein allows for precise targeting of specific genomic sites, and the FRB-mCherry-HP1α fusion protein facilitates the condensation of chromatin at the targeted loci. The scFv-FKBP bridge protein links dCas9-SunTag and FRB-mCherry-HP1α, ensuring efficient and specific recruitment of HP1α to the desired genomic loci. This integrated approach allows us to visualize and manipulate genomic regions of interest, opening up new avenues for studying genome organization, gene expression regulation, and chromatin dynamics in living cells. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Cloning of genetic constructs Basic Protocol 2: Transient transfection in mammalian cells and live-cell imaging Basic Protocol 3: Generation of SIMBA-expressing stable cell lines Basic Protocol 4: Manipulation of genomic loci using SIMBA.
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Affiliation(s)
- Yanwei Chen
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Ziliang Huang
- Alfred E. Mann Department of Biomedical Engineering, University of Southern California, Los Angeles, California
| | - Qin Peng
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Yingxiao Wang
- Alfred E. Mann Department of Biomedical Engineering, University of Southern California, Los Angeles, California
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Herrick J. Kimura's Theory of Non-Adaptive Radiation and Peto's Paradox: A Missing Link? BIOLOGY 2023; 12:1140. [PMID: 37627024 PMCID: PMC10452704 DOI: 10.3390/biology12081140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/07/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023]
Abstract
Karyotype diversity reflects genome integrity and stability. A strong correlation between karyotype diversity and species richness, meaning the number of species in a phylogenetic clade, was first reported in mammals over forty years ago: in mammalian phylogenetic clades, the standard deviation of karyotype diversity (KD) closely corresponded to species richness (SR) at the order level. These initial studies, however, did not control for phylogenetic signal, raising the possibility that the correlation was due to phylogenetic relatedness among species in a clade. Accordingly, karyotype diversity trivially reflects species richness simply as a passive consequence of adaptive radiation. A more recent study in mammals controlled for phylogenetic signals and established the correlation as phylogenetically independent, suggesting that species richness cannot, in itself, explain the observed corresponding karyotype diversity. The correlation is, therefore, remarkable because the molecular mechanisms contributing to karyotype diversity are evolutionarily independent of the ecological mechanisms contributing to species richness. Recently, it was shown in salamanders that the two processes generating genome size diversity and species richness were indeed independent and operate in parallel, suggesting a potential non-adaptive, non-causal but biologically meaningful relationship. KD depends on mutational input generating genetic diversity and reflects genome stability, whereas species richness depends on ecological factors and reflects natural selection acting on phenotypic diversity. As mutation and selection operate independently and involve separate and unrelated evolutionary mechanisms-there is no reason a priori to expect such a strong, let alone any, correlation between KD and SR. That such a correlation exists is more consistent with Kimura's theory of non-adaptive radiation than with ecologically based adaptive theories of macro-evolution, which are not excluded in Kimura's non-adaptive theory. The following reviews recent evidence in support of Kimura's proposal, and other findings that contribute to a wider understanding of the molecular mechanisms underlying the process of non-adaptive radiation.
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Affiliation(s)
- John Herrick
- Independent Researcher, 3, rue des Jeûneurs, 75002 Paris, France
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Zhou J, Lei X, Shafiq S, Zhang W, Li Q, Li K, Zhu J, Dong Z, He XJ, Sun Q. DDM1-mediated R-loop resolution and H2A.Z exclusion facilitates heterochromatin formation in Arabidopsis. SCIENCE ADVANCES 2023; 9:eadg2699. [PMID: 37566662 PMCID: PMC10421056 DOI: 10.1126/sciadv.adg2699] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 07/13/2023] [Indexed: 08/13/2023]
Abstract
Programmed constitutive heterochromatin silencing is essential for eukaryotic genome regulation, yet the initial step of this process is ambiguous. A large proportion of R-loops (RNA:DNA hybrids) had been unexpectedly identified within Arabidopsis pericentromeric heterochromatin with unknown functions. Through a genome-wide R-loop profiling screen, we find that DDM1 (decrease in DNA methylation 1) is the primary restrictor of pericentromeric R-loops via its RNA:DNA helicase activity. Low levels of pericentromeric R-loops resolved by DDM1 cotranscriptionally can facilitate constitutive heterochromatin silencing. Furthermore, we demonstrate that DDM1 physically excludes histone H2A variant H2A.Z and promotes H2A.W deposition for faithful heterochromatin initiation soon after R-loop clearance. The dual functions of DDM1 in R-loop resolution and H2A.Z eviction are essential for sperm nuclei structure maintenance in mature pollen. Our work unravels the cotranscriptional R-loop resolution coupled with accurate H2A variants deposition is the primary step of constitutive heterochromatin silencing in Arabidopsis, which might be conserved across eukaryotes.
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Affiliation(s)
- Jincong Zhou
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Xue Lei
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Sarfraz Shafiq
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Weifeng Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Qin Li
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Kuan Li
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Jiafu Zhu
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Zhicheng Dong
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Xin-jian He
- National Institute of Biological Sciences, Beijing, China
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
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11
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Zhang X, Yu Q, Wu Y, Zhang Y, He Y, Wang R, Yu X, Li S. Glc7/PP1 dephosphorylates histone H3T11 to regulate autophagy and telomere silencing in response to nutrient availability. Cell Discov 2023; 9:71. [PMID: 37433812 DOI: 10.1038/s41421-023-00551-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 04/02/2023] [Indexed: 07/13/2023] Open
Abstract
How cells adapt their gene expression to nutritional changes remains poorly understood. Histone H3T11 is phosphorylated by pyruvate kinase to repress gene transcription. Here, we identify the protein phosphatase 1 (PP1), Glc7 as the enzyme that specifically dephosphorylates H3T11. We also characterize two novel Glc7-containing complexes and reveal their roles in regulating gene expression upon glucose starvation. Specifically, the Glc7-Sen1 complex dephosphorylates H3T11 to activate the transcription of autophagy-related genes. The Glc7-Rif1-Rap1 complex dephosphorylates H3T11 to derepress the transcription of telomere-proximal genes. Upon glucose starvation, Glc7 expression is up-regulated and more Glc7 translocates into the nucleus to dephosphorylate H3T11, leading to induction of autophagy and derepressed transcription of telomere-proximal genes. Furthermore, the functions of PP1/Glc7 and the two Glc7-containing complexes are conserved in mammals to regulate autophagy and telomere structure. Collectively, our results reveal a novel mechanism that regulate gene expression and chromatin structure in response to glucose availability.
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Affiliation(s)
- Xinyu Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Qi Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Yinsheng Wu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Yuan Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Yi He
- State Key Laboratory of Biocatalysis and Enzyme Engineering, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Rongsha Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Xilan Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of Life Sciences, Hubei University, Wuhan, Hubei, China.
| | - Shanshan Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of Life Sciences, Hubei University, Wuhan, Hubei, China.
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12
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Manna S, Mishra J, Baral T, Kirtana R, Nandi P, Roy A, Chakraborty S, Niharika, Patra SK. Epigenetic signaling and crosstalk in regulation of gene expression and disease progression. Epigenomics 2023; 15:723-740. [PMID: 37661861 DOI: 10.2217/epi-2023-0235] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023] Open
Abstract
Chromatin modifications - including DNA methylation, modification of histones and recruitment of noncoding RNAs - are essential epigenetic events. Multiple sequential modifications converge into a complex epigenetic landscape. For example, promoter DNA methylation is recognized by MeCP2/methyl CpG binding domain proteins which further recruit SETDB1/SUV39 to attain a higher order chromatin structure by propagation of inactive epigenetic marks like H3K9me3. Many studies with new information on different epigenetic modifications and associated factors are available, but clear maps of interconnected pathways are also emerging. This review deals with the salient epigenetic crosstalk mechanisms that cells utilize for different cellular processes and how deregulation or aberrant gene expression leads to disease progression.
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Affiliation(s)
- Soumen Manna
- Epigenetics & Cancer Research Laboratory, Biochemistry & Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
| | - Jagdish Mishra
- Epigenetics & Cancer Research Laboratory, Biochemistry & Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
| | - Tirthankar Baral
- Epigenetics & Cancer Research Laboratory, Biochemistry & Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
| | - R Kirtana
- Epigenetics & Cancer Research Laboratory, Biochemistry & Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
| | - Piyasa Nandi
- Epigenetics & Cancer Research Laboratory, Biochemistry & Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
| | - Ankan Roy
- Epigenetics & Cancer Research Laboratory, Biochemistry & Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
| | - Subhajit Chakraborty
- Epigenetics & Cancer Research Laboratory, Biochemistry & Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
| | - Niharika
- Epigenetics & Cancer Research Laboratory, Biochemistry & Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
| | - Samir K Patra
- Epigenetics & Cancer Research Laboratory, Biochemistry & Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769008, India
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13
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Xing Y, Larson K, Li J, Li WX. Canonical and non-canonical functions of STAT in germline stem cell maintenance. Dev Dyn 2023; 252:728-741. [PMID: 36866634 PMCID: PMC10238624 DOI: 10.1002/dvdy.576] [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: 11/08/2022] [Revised: 02/01/2023] [Accepted: 02/09/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Maintenance of the Drosophila male germline stem cells (GSCs) requires activation of the Janus kinase/signal transducer and activators of transcription (JAK/STAT) pathway by niche signals. The precise role of JAK/STAT signaling in GSC maintenance, however, remains incompletely understood. RESULTS Here, we show that, GSC maintenance requires both canonical and non-canonical JAK/STAT signaling, in which unphosphorylated STAT (uSTAT) maintains heterochromatin stability by binding to heterochromatin protein 1 (HP1). We found that GSC-specific overexpressing STAT, or even the transcriptionally inactive mutant STAT, increases GSC number and partially rescues the GSC-loss mutant phenotype due to reduced JAK activity. Furthermore, we found that both HP1 and STAT are transcriptional targets of the canonical JAK/STAT pathway in GSCs, and that GSCs exhibit higher heterochromatin content. CONCLUSIONS These results suggest that persistent JAK/STAT activation by niche signals leads to the accumulation of HP1 and uSTAT in GSCs, which promote heterochromatin formation important for maintaining GSC identity. Thus, the maintenance of Drosophila GSCs requires both canonical and non-canonical STAT functions within GSCs for heterochromatin regulation.
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Affiliation(s)
- Yalan Xing
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642
| | - Kimberly Larson
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642
| | - Jinghong Li
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093
| | - Willis X. Li
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642
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14
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Wright GM, Menzel J, Tatman PD, Black JC. Transition from Transient DNA Rereplication to Inherited Gene Amplification Following Prolonged Environmental Stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539886. [PMID: 37214911 PMCID: PMC10197558 DOI: 10.1101/2023.05.08.539886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cells require the ability to adapt to changing environmental conditions, however, it is unclear how these changes elicit stable permanent changes in genomes. We demonstrate that, in response to environmental metal exposure, the metallothionein (MT) locus undergoes DNA rereplication generating transient site-specific gene amplifications (TSSGs). Chronic metal exposure allows transition from MT TSSG to inherited MT gene amplification through homologous recombination within and outside of the MT locus. DNA rereplication of the MT locus is suppressed by H3K27me3 and EZH2. Long-term ablation of EZH2 activity eventually leads to integration and inheritance of MT gene amplifications without the selective pressure of metal exposure. The rereplication and inheritance of MT gene amplification is an evolutionarily conserved response to environmental metal from yeast to human. Our results describe a new paradigm for adaptation to environmental stress where targeted, transient DNA rereplication precedes stable inherited gene amplification.
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15
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Bobadilla Ugarte P, Barendse P, Swarts DC. Argonaute proteins confer immunity in all domains of life. Curr Opin Microbiol 2023; 74:102313. [PMID: 37023508 DOI: 10.1016/j.mib.2023.102313] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 03/10/2023] [Accepted: 03/10/2023] [Indexed: 04/08/2023]
Abstract
Both eukaryotes and prokaryotes (archaea and bacteria) encode an arsenal of immune systems that protect the host against mobile genetic elements (MGEs) including viruses, plasmids, and transposons. Whereas Argonaute proteins (Agos) are best known for post-transcriptional gene silencing in eukaryotes, in all domains of life, members from the highly diverse Argonaute protein family act as programmable immune systems. To this end, Agos are programmed with small single-stranded RNA or DNA guides to detect and silence complementary MGEs. Across and within the different domains of life, Agos function in distinct pathways and MGE detection can trigger various mechanisms that provide immunity. In this review, we delineate the diverse immune pathways and underlying mechanisms for both eukaryotic Argonautes (eAgos) and prokaryotic Argonautes (pAgos).
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Affiliation(s)
| | - Patrick Barendse
- Laboratory of Biochemistry, Wageningen University, 6708 WE Wageningen, The Netherlands
| | - Daan C Swarts
- Laboratory of Biochemistry, Wageningen University, 6708 WE Wageningen, The Netherlands.
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16
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Kim H, Suyama M. Genome-wide identification of copy neutral loss of heterozygosity reveals its possible association with spatial positioning of chromosomes. Hum Mol Genet 2023; 32:1175-1183. [PMID: 36349694 PMCID: PMC10026252 DOI: 10.1093/hmg/ddac278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/17/2022] [Accepted: 11/02/2022] [Indexed: 11/10/2022] Open
Abstract
Loss of heterozygosity (LOH) is a genetic alteration that results from the loss of one allele at a heterozygous locus. In particular, copy neutral LOH (CN-LOH) events are generated, for example, by mitotic homologous recombination after monoallelic defection or gene conversion, resulting in novel homozygous locus having two copies of the normal counterpart allele. This phenomenon can serve as a source of genome diversity and is associated with various diseases. To clarify the nature of the CN-LOH such as the frequency, genomic distribution and inheritance pattern, we made use of whole-genome sequencing data of the three-generation CEPH/Utah family cohort, with the pedigree consisting of grandparents, parents and offspring. We identified an average of 40.7 CN-LOH events per individual taking advantage of 285 healthy individuals from 33 families in the cohort. On average 65% of them were classified as gonosomal-mosaicism-associated CN-LOH, which exists in both germline and somatic cells. We also confirmed that the incidence of the CN-LOH has little to do with the parents' age and sex. Furthermore, through the analysis of the genomic region including the CN-LOH, we found that the chance of the occurrence of the CN-LOH tends to increase at the GC-rich locus and/or on the chromosome having a relatively close inter-homolog distance. We expect that these results provide significant insights into the association between genetic alteration and spatial position of chromosomes as well as the intrinsic genetic property of the CN-LOH.
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Affiliation(s)
- Hyeonjeong Kim
- Division of Bioinformatics, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Mikita Suyama
- Division of Bioinformatics, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
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17
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Bruno S, Vecchio DD. The epigenetic Oct4 gene regulatory network: stochastic analysis of different cellular reprogramming approaches. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.01.530689. [PMID: 36909486 PMCID: PMC10002722 DOI: 10.1101/2023.03.01.530689] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
In the last decade, several experimental studies have shown how chromatin modifications (histone modifications and DNA methylation) and their effect on DNA compaction have a critical effect on cellular reprogramming, i.e., the conversion of differentiated cells to a pluripotent state. In this paper, we compare three reprogramming approaches that have been considered in the literature: (a) prefixed overexpression of transcription factors (TFs) alone (Oct4), (b) prefixed overexpression of Oct4 and DNA methylation "eraser" TET, and (c) prefixed overexpression of Oct4 and H3K9me3 eraser JMJD2. To this end, we develop a model of the pluritpotency gene regulatory network, that includes, for each gene, a circuit recently published encapsulating the main interactions among chromatin modifications and their effect on gene expression. We then conduct a computational study to evaluate, for each reprogramming approach, latency and variability. Our results show a faster and less stochastic reprogramming process when also eraser enzymes are overexpressed, consistent with previous experimental data. However, TET overexpression leads to a faster and more efficient reprogramming compared to JMJD2 overexpression when the recruitment of DNA methylation by H3K9me3 is weak and the MBD protein level is sufficiently low such that it does not hamper TET binding to methylated DNA. The model developed here provides a mechanistic understanding of the outcomes of former experimental studies and is also a tool for the development of optimized reprogramming approaches that combine TF overexpression with modifiers of chromatin state.
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Affiliation(s)
- Simone Bruno
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139
| | - Domitilla Del Vecchio
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139
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18
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Mei Q, Yu Q, Li X, Chen J, Yu X. Regulation of telomere silencing by the core histones-autophagy-Sir2 axis. Life Sci Alliance 2023; 6:6/3/e202201614. [PMID: 36585257 PMCID: PMC9806677 DOI: 10.26508/lsa.202201614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 12/18/2022] [Accepted: 12/19/2022] [Indexed: 12/31/2022] Open
Abstract
Telomeres contain compacted heterochromatin, and genes adjacent to telomeres are subjected to transcription silencing. Maintaining telomere structure integrity and transcription silencing is important to prevent the occurrence of premature aging and aging-related diseases. How telomere silencing is regulated during aging is not well understood. Here, we find that the four core histones are reduced during yeast chronological aging, leading to compromised telomere silencing. Mechanistically, histone loss promotes the nuclear export of Sir2 and its degradation by autophagy. Meanwhile, reducing core histones enhances the autophagy pathway, which further accelerates autophagy-mediated Sir2 degradation. By screening the histone mutant library, we identify eight histone mutants and one histone modification (histone methyltransferase Set1-catalyzed H3K4 trimethylation) that regulate telomere silencing by modulating the core histones-autophagy-Sir2 axis. Overall, our findings reveal core histones and autophagy as causes of aging-coupled loss of telomere silencing and shed light on dynamic regulation of telomere structure during aging.
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Affiliation(s)
- Qianyun Mei
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China
| | - Qi Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China
| | - Xin Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China
| | - Jianguo Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China
| | - Xilan Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China
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19
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Idriss S, Hallal M, El-Kurdi A, Zalzali H, El-Rassi I, Ehli EA, Davis CM, Chung PED, Gendoo DMA, Zacksenhaus E, Saab R, Khoueiry P. A temporal in vivo catalog of chromatin accessibility and expression profiles in pineoblastoma reveals a prevalent role for repressor elements. Genome Res 2023; 33:269-282. [PMID: 36650051 PMCID: PMC10069464 DOI: 10.1101/gr.277037.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 01/11/2023] [Indexed: 01/19/2023]
Abstract
Pediatric pineoblastomas (PBs) are rare and aggressive tumors of grade IV histology. Although some oncogenic drivers are characterized, including germline mutations in RB1 and DICER1, the role of epigenetic deregulation and cis-regulatory regions in PB pathogenesis and progression is largely unknown. Here, we generated genome-wide gene expression, chromatin accessibility, and H3K27ac profiles covering key time points of PB initiation and progression from pineal tissues of a mouse model of CCND1-driven PB. We identified PB-specific enhancers and super-enhancers, and found that in some cases, the accessible genome dynamics precede transcriptomic changes, a characteristic that is underexplored in tumor progression. During progression of PB, newly acquired open chromatin regions lacking H3K27ac signal become enriched for repressive state elements and harbor motifs of repressor transcription factors like HINFP, GLI2, and YY1. Copy number variant analysis identified deletion events specific to the tumorigenic stage, affecting, among others, the histone gene cluster and Gas1, the growth arrest specific gene. Gene set enrichment analysis and gene expression signatures positioned the model used here close to human PB samples, showing the potential of our findings for exploring new avenues in PB management and therapy. Overall, this study reports the first temporal and in vivo cis-regulatory, expression, and accessibility maps in PB.
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Affiliation(s)
- Salam Idriss
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Mohammad Hallal
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon.,Biomedical Engineering Program, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Abdullah El-Kurdi
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon.,Pillar Genomics Institute, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Hasan Zalzali
- Department of Pediatric and Adolescent Medicine, American University of Beirut, Beirut 1107 2020, Lebanon.,Department of Anatomy, Cell Biology, and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Inaam El-Rassi
- Biomedical Engineering Program, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Erik A Ehli
- Avera Institute for Human Genetics, Sioux Falls, South Dakota 57108, USA
| | - Christel M Davis
- Avera Institute for Human Genetics, Sioux Falls, South Dakota 57108, USA
| | - Philip E D Chung
- Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 1L7, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Deena M A Gendoo
- Centre for Computational Biology, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2SY, United Kingdom
| | - Eldad Zacksenhaus
- Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 1L7, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Raya Saab
- Department of Pediatric and Adolescent Medicine, American University of Beirut, Beirut 1107 2020, Lebanon.,Department of Anatomy, Cell Biology, and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Pierre Khoueiry
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon; .,Pillar Genomics Institute, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon
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20
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Peng Q, Huang Z, Sun K, Liu Y, Yoon CW, Harrison RES, Schmitt DL, Zhu L, Wu Y, Tasan I, Zhao H, Zhang J, Zhong S, Chien S, Wang Y. Engineering inducible biomolecular assemblies for genome imaging and manipulation in living cells. Nat Commun 2022; 13:7933. [PMID: 36566209 PMCID: PMC9789998 DOI: 10.1038/s41467-022-35504-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 12/06/2022] [Indexed: 12/25/2022] Open
Abstract
Genome architecture and organization play critical roles in cell life. However, it remains largely unknown how genomic loci are dynamically coordinated to regulate gene expression and determine cell fate at the single cell level. We have developed an inducible system which allows Simultaneous Imaging and Manipulation of genomic loci by Biomolecular Assemblies (SIMBA) in living cells. In SIMBA, the human heterochromatin protein 1α (HP1α) is fused to mCherry and FRB, which can be induced to form biomolecular assemblies (BAs) with FKBP-scFv, guided to specific genomic loci by a nuclease-defective Cas9 (dCas9) or a transcriptional factor (TF) carrying tandem repeats of SunTag. The induced BAs can not only enhance the imaging signals at target genomic loci using a single sgRNA, either at repetitive or non-repetitive sequences, but also recruit epigenetic modulators such as histone methyltransferase SUV39H1 to locally repress transcription. As such, SIMBA can be applied to simultaneously visualize and manipulate, in principle, any genomic locus with controllable timing in living cells.
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Affiliation(s)
- Qin Peng
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA.
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, 518132, P. R. China.
| | - Ziliang Huang
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA
| | - Kun Sun
- Institute of Cancer Research, Shenzhen Bay Laboratory, Shenzhen, 518132, P. R. China
| | - Yahan Liu
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA
| | - Chi Woo Yoon
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA
| | - Reed E S Harrison
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA
| | - Danielle L Schmitt
- Department of Pharmacology, University of California, La Jolla, CA, 92093-0435, USA
| | - Linshan Zhu
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA
| | - Yiqian Wu
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA
| | - Ipek Tasan
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Huimin Zhao
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana-Champaign, Urbana, IL, 61801, USA
| | - Jin Zhang
- Department of Pharmacology, University of California, La Jolla, CA, 92093-0435, USA
| | - Sheng Zhong
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA
| | - Shu Chien
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA
- Department of Medicine, University of California, La Jolla, CA, 92093-0435, USA
| | - Yingxiao Wang
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, La Jolla, CA, 92093-0435, USA.
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21
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Rhodes ADY, Duran-Mota JA, Oliva N. Current progress in bionanomaterials to modulate the epigenome. Biomater Sci 2022; 10:5081-5091. [PMID: 35880652 DOI: 10.1039/d2bm01027e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent advances in genomics during the 1990s have made it possible to study and identify genetic and epigenetic responses of cells and tissues to various drugs and environmental factors. This has accelerated the number of targets available to treat a range of diseases from cancer to wound healing disorders. Equally interesting is the understanding of how bio- and nanomaterials alter gene expression through epigenetic mechanisms, and whether they have the potential to elicit a positive therapeutic response without requiring additional biomolecule delivery. In fact, from a cell's perspective, a biomaterial is nothing more than an environmental factor, and so it has the power to epigenetically modulate gene expression of cells in contact with it. Understanding these epigenetic interactions between biomaterials and cells will open new avenues in the development of technologies that can not only provide biological signals (i.e. drugs, growth factors) necessary for therapy and regeneration, but also intimately interact with cells to promote the expression of genes of interest. This review article aims to summarise the current state-of-the-art and progress on the development of bio- and nanomaterials to modulate the epigenome.
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Affiliation(s)
- Anna D Y Rhodes
- Department of Bioengineering, Imperial College London, London W12 0BZ, UK.
| | - Jose Antonio Duran-Mota
- Department of Bioengineering, Imperial College London, London W12 0BZ, UK. .,Materials Engineering Group (GEMAT), IQS Barcelona, Barcelona 08017, Spain
| | - Nuria Oliva
- Department of Bioengineering, Imperial College London, London W12 0BZ, UK.
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22
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Sen S, Dodamani A, Nambiar M. Emerging mechanisms and roles of meiotic crossover repression at centromeres. Curr Top Dev Biol 2022; 151:155-190. [PMID: 36681469 DOI: 10.1016/bs.ctdb.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Crossover events during recombination in meiosis are essential for generating genetic diversity as well as crucial to allow accurate chromosomal segregation between homologous chromosomes. Spatial control for the distribution of crossover events along the chromosomes is largely a tightly regulated process and involves many facets such as interference, repression as well as assurance, to make sure that not too many or too few crossovers are generated. Repression of crossover events at the centromeres is a highly conserved process across all species tested. Failure to inhibit such recombination events can result in chromosomal mis-segregation during meiosis resulting in aneuploid gametes that are responsible for infertility or developmental disorders such as Down's syndrome and other trisomies in humans. In the past few decades, studies to understand the molecular mechanisms behind this repression have shown the involvement of a multitude of factors ranging from the centromere-specific proteins such as the kinetochore to the flanking pericentric heterochromatin as well as DNA double-strand break repair pathways. In this chapter, we review the different mechanisms of pericentric repression mechanisms known till date as well as highlight the importance of understanding this regulation in the context of chromosomal segregation defects. We also discuss the clinical implications of dysregulation of this process, especially in human reproductive health and genetic diseases.
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Affiliation(s)
- Sucharita Sen
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Ananya Dodamani
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Mridula Nambiar
- Department of Biology, Indian Institute of Science Education and Research, Pune, India.
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23
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Haarhuis JHI, van der Weide RH, Blomen VA, Flach KD, Teunissen H, Willems L, Brummelkamp TR, Rowland BD, de Wit E. A Mediator-cohesin axis controls heterochromatin domain formation. Nat Commun 2022; 13:754. [PMID: 35136067 PMCID: PMC8826356 DOI: 10.1038/s41467-022-28377-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 01/20/2022] [Indexed: 02/06/2023] Open
Abstract
The genome consists of regions of transcriptionally active euchromatin and more silent heterochromatin. We reveal that the formation of heterochromatin domains requires cohesin turnover on DNA. Stabilization of cohesin on DNA through depletion of its release factor WAPL leads to a near-complete loss of heterochromatin domains. We observe the opposite phenotype in cells deficient for subunits of the Mediator-CDK module, with an almost binary partition of the genome into dense H3K9me3 domains, and regions devoid of H3K9me3 spanning the rest of the genome. We suggest that the Mediator-CDK module might contribute to gene expression by limiting the formation of dense heterochromatin domains. WAPL deficiency prevents the formation of heterochromatin domains, and allows for gene expression even in the absence of the Mediator-CDK subunit MED12. We propose that cohesin and Mediator affect heterochromatin in different ways to enable the correct distribution of epigenetic marks, and thus to ensure proper gene expression.
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Affiliation(s)
- Judith H I Haarhuis
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Robin H van der Weide
- Division of Gene Regulation, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
- Hubrecht Institute-KNAW, Utrecht, The Netherlands
| | - Vincent A Blomen
- Division of Biochemistry, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Koen D Flach
- Division of Gene Regulation, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Hans Teunissen
- Division of Gene Regulation, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Laureen Willems
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Thijn R Brummelkamp
- Division of Biochemistry, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Benjamin D Rowland
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
| | - Elzo de Wit
- Division of Gene Regulation, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
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24
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Kawai T, Richards JS, Shimada M. Large-scale DNA demethylation occurs in proliferating ovarian granulosa cells during mouse follicular development. Commun Biol 2021; 4:1334. [PMID: 34824385 PMCID: PMC8617273 DOI: 10.1038/s42003-021-02849-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 11/04/2021] [Indexed: 12/20/2022] Open
Abstract
During ovarian follicular development, granulosa cells proliferate and progressively differentiate to support oocyte maturation and ovulation. To determine the underlying links between proliferation and differentiation in granulosa cells, we determined changes in 1) the expression of genes regulating DNA methylation and 2) DNA methylation patterns, histone acetylation levels and genomic DNA structure. In response to equine chorionic gonadotropin (eCG), granulosa cell proliferation increased, DNA methyltransferase (DNMT1) significantly decreased and Tet methylcytosine dioxygenase 2 (TET2) significantly increased in S-phase granulosa cells. Comprehensive MeDIP-seq analyses documented that eCG treatment decreased methylation of promoter regions in approximately 40% of the genes in granulosa cells. The expression of specific demethylated genes was significantly increased in association with specific histone modifications and changes in DNA structure. These epigenetic processes were suppressed by a cell cycle inhibitor. Based on these results, we propose that the timing of sequential epigenetic events is essential for progressive, stepwise changes in granulosa cell differentiation.
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Affiliation(s)
- Tomoko Kawai
- Laboratory of Reproductive Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Japan
| | - JoAnne S Richards
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Masayuki Shimada
- Laboratory of Reproductive Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Japan.
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25
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26
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Xiao Z, Locasale JW. Epigenomic links from metabolism-methionine and chromatin architecture. Curr Opin Chem Biol 2021; 63:11-18. [PMID: 33667809 PMCID: PMC9889272 DOI: 10.1016/j.cbpa.2021.01.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/12/2021] [Accepted: 01/31/2021] [Indexed: 02/03/2023]
Abstract
Chromatin and associated epigenetic marks provide important platforms for gene regulation in response to metabolic changes associated with environmental exposures, including physiological stress, nutritional deprivation, and starvation. Numerous studies have shown that fluctuations of key metabolites can influence chromatin modifications, but their effects on chromatin structure (e.g. chromatin compaction, nucleosome arrangement, and chromatin loops) and how they appropriately deposit specific chemical modification on chromatin are largely unknown. Here, focusing on methionine metabolism, we discuss recent developments of metabolic effects on chromatin modifications and structure, as well as consequences on gene regulation.
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Affiliation(s)
- Zhengtao Xiao
- School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
| | - Jason W Locasale
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA.
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27
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Amemiya HM, Schroeder J, Freddolino PL. Nucleoid-associated proteins shape chromatin structure and transcriptional regulation across the bacterial kingdom. Transcription 2021; 12:182-218. [PMID: 34499567 PMCID: PMC8632127 DOI: 10.1080/21541264.2021.1973865] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 01/21/2023] Open
Abstract
Genome architecture has proven to be critical in determining gene regulation across almost all domains of life. While many of the key components and mechanisms of eukaryotic genome organization have been described, the interplay between bacterial DNA organization and gene regulation is only now being fully appreciated. An increasing pool of evidence has demonstrated that the bacterial chromosome can reasonably be thought of as chromatin, and that bacterial chromosomes contain transcriptionally silent and transcriptionally active regions analogous to heterochromatin and euchromatin, respectively. The roles played by histones in eukaryotic systems appear to be shared across a range of nucleoid-associated proteins (NAPs) in bacteria, which function to compact, structure, and regulate large portions of bacterial chromosomes. The broad range of extant NAPs, and the extent to which they differ from species to species, has raised additional challenges in identifying and characterizing their roles in all but a handful of model bacteria. Here we review the regulatory roles played by NAPs in several well-studied bacteria and use the resulting state of knowledge to provide a working definition for NAPs, based on their function, binding pattern, and expression levels. We present a screening procedure which can be applied to any species for which transcriptomic data are available. Finally, we note that NAPs tend to play two major regulatory roles - xenogeneic silencers and developmental regulators - and that many unrecognized potential NAPs exist in each bacterial species examined.
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Affiliation(s)
- Haley M. Amemiya
- University of Michigan Medical School, Ann Arbor, MI, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jeremy Schroeder
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Peter L. Freddolino
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
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28
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Fan X, Zhu Y, Wang N, Zhang B, Zhang C, Wang Y. Therapeutic Dose of Hydroxyurea-Induced Synaptic Abnormalities on the Mouse Spermatocyte. Front Physiol 2021; 12:666339. [PMID: 34305635 PMCID: PMC8299468 DOI: 10.3389/fphys.2021.666339] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 06/14/2021] [Indexed: 12/30/2022] Open
Abstract
Hydroxyurea (HU) is a widely used pharmacological therapy for sickle cell disease (SCD). However, replication stress caused by HU has been shown to inhibit premeiotic S-phase DNA, leading to reproductive toxicity in germ cells. In this study, we administered the therapeutic doses of HU (i.e., 25 and 50 mg/kg) to male mice to explore whether replication stress by HU affects pachytene spermatocytes and causes the abnormalities of homologous chromosomes pairing and recombination during prophase I of meiosis. In comparison with the control group, the proportions of spermatocyte gaps were significantly different in the experimental groups injected with 25 mg/kg (p < 0.05) and 50 mg/kg of HU (p < 0.05). Moreover, the proportions of unrepaired double-stranded breaks (DSBs) observed by γH2AX staining also corresponded to a higher HU dose with a greater number of breaks. Additionally, a reduction in the counts of recombination foci on the autosomal SCs was observed in the pachytene spermatocytes. Our results reveal that HU has some effects on synaptonemal complex (SC) formation and DSB repair which suggest possible problems in fertility. Therefore, this study provides new evidence of the mechanisms underlying HU reproductive toxicity.
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Affiliation(s)
- Xiaobo Fan
- Laboratory of Molecular Cytogenetics, School of Bioengineering, Xuzhou University of Technology, Xuzhou, China
| | - Yunxia Zhu
- The Center of Reproductive Medicine, Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Naixin Wang
- Laboratory of Molecular Cytogenetics, School of Bioengineering, Xuzhou University of Technology, Xuzhou, China
| | - Bing Zhang
- Laboratory of Molecular Cytogenetics, School of Bioengineering, Xuzhou University of Technology, Xuzhou, China
| | - Cui Zhang
- Laboratory of Molecular Cytogenetics, School of Bioengineering, Xuzhou University of Technology, Xuzhou, China
| | - Yanan Wang
- Laboratory of Molecular Cytogenetics, School of Bioengineering, Xuzhou University of Technology, Xuzhou, China
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29
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Mendonca A, Sánchez OF, Xie J, Carneiro A, Lin L, Yuan C. Identifying distinct heterochromatin regions using combinatorial epigenetic probes in live cells. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2021; 1864:194725. [PMID: 34174495 DOI: 10.1016/j.bbagrm.2021.194725] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
Abstract
The 3D spatial organization of the genome controls gene expression and cell functionality. Heterochromatin (HC), which is the densely compacted and largely silenced part of the chromatin, is the driver for the formation and maintenance of nuclear organization in the mammalian nucleus. It is functionally divided into highly compact constitutive heterochromatin (cHC) and transcriptionally poised facultative heterochromatin (fHC). Long regarded as a static structure, the highly dynamic nature of the heterochromatin is being slowly understood and studied. These changes in HC occur on various temporal scales during the cell cycle and differentiation processes. Most methods that capture information about the heterochromatin are static techniques that cannot provide a readout of how the HC organization evolves with time. The delineation of specific areas such as fHC are also rendered difficult due to its diffusive nature and lack of specific features. Another degree of complexity in characterizing changes in heterochromatin occurs due to the heterogeneity in the HC organization of individual cells, necessitating single cell studies. Overall, there is a need for live cell compatible tools that can stably track the heterochromatin as it undergoes re-organization. In this work, we present an approach to track cHC and fHC based on the epigenetic hallmarks associated with them. Unlike conventional immunostaining approaches, we use small recombinant protein probes that allow us to dynamically monitor the HC by binding to modifications specific to the cHC and fHC, such as H3K9me3, DNA methylation and H3K27me3. We demonstrate the use of the probes to follow the changes in HC induced by drug perturbations at the single cell level. We also use the probe sets combinatorically to simultaneously track chromatin regions enriched in two selected epigenetic modifications using a FRET based approach that enabled us tracking distinctive chromatin features in situ.
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Affiliation(s)
- Agnes Mendonca
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Oscar F Sánchez
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Junkai Xie
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Ana Carneiro
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Li Lin
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Chongli Yuan
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA; Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47906, USA.
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30
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Suetake I, Nakazawa S, Sato K, Mutoh R, Mishima Y, Kawakami T, Takei T, Watanabe M, Sakai N, Fujiwara T, Takui T, Miyata M, Shinohara A, Hojo H, Arata T. Structural dynamics of the chromo-shadow domain and chromodomain of HP1 bound to histone H3K9 methylated peptide, as measured by site-directed spin-labeling EPR spectroscopy. Biochem Biophys Res Commun 2021; 567:42-48. [PMID: 34139556 DOI: 10.1016/j.bbrc.2021.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 06/03/2021] [Indexed: 10/21/2022]
Abstract
The structural dynamics of the chromo-shadow domain (CSD) and chromodomain (CD) of human HP1 proteins essential for heterochromatin formation were investigated at the nanosecond and nanometer scales by site-directed spin labeling electron paramagnetic resonance and pulsed double resonance spectroscopy. Distance measurements showed that the spin-labeled CSD of human HP1α and HP1γ tightly dimerizes. Unlike CD-CD interaction observed in fission yeast HP1 in an inactivated state (Canzio et al., 2013), the two CDs of HP1α and HP1γ were spatially separated from each other, dynamically mobile, and ready for a Brownian search for H3K9-tri-methyl(me3) on histones. Complex formation of the CD with H3K9me3 slowed dynamics of the domain due to a decreased diffusion constant. CSD mobility was significantly (∼1.3-fold) lower in full-length HP1α than in HP1γ, suggesting that the immobilized conformation of human HP1α shows an auto-inactivated state. Differential properties of HP1α and HP1γ to form the inactive conformation could be relevant to its physiological role in the heterochromatin formation in a cell.
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Affiliation(s)
- Isao Suetake
- Institute for Protein Research, Osaka University, Osaka, 565-0871, Japan; Center for Twin Research, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan; Department of Nutritional Sciences, Graduate School of Nutritional Sciences, Nakamura Gakuen University, Fukuoka, 814-0198, Japan.
| | - Shigeaki Nakazawa
- Department of Chemistry and Molecular Materials Sciences, Graduate School of Science, Osaka City University, Osaka, 558-8585, Japan
| | - Kazunobu Sato
- Department of Chemistry and Molecular Materials Sciences, Graduate School of Science, Osaka City University, Osaka, 558-8585, Japan
| | - Risa Mutoh
- Department of Applied Physics, Faculty of Science, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Yuichi Mishima
- Institute for Protein Research, Osaka University, Osaka, 565-0871, Japan
| | - Toru Kawakami
- Institute for Protein Research, Osaka University, Osaka, 565-0871, Japan
| | - Toshiki Takei
- Institute for Protein Research, Osaka University, Osaka, 565-0871, Japan
| | - Mikio Watanabe
- Center for Twin Research, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
| | - Norio Sakai
- Center for Twin Research, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
| | | | - Takeji Takui
- Department of Chemistry and Molecular Materials Sciences, Graduate School of Science, Osaka City University, Osaka, 558-8585, Japan
| | - Makoto Miyata
- Department of Biology, Graduate School of Science, Osaka City University, Osaka, 558-8585, Japan
| | - Akira Shinohara
- Institute for Protein Research, Osaka University, Osaka, 565-0871, Japan
| | - Hironobu Hojo
- Institute for Protein Research, Osaka University, Osaka, 565-0871, Japan
| | - Toshiaki Arata
- Institute for Protein Research, Osaka University, Osaka, 565-0871, Japan; Department of Biology, Graduate School of Science, Osaka City University, Osaka, 558-8585, Japan.
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31
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Yadav VK, Santos-González J, Köhler C. INT-Hi-C reveals distinct chromatin architecture in endosperm and leaf tissues of Arabidopsis. Nucleic Acids Res 2021; 49:4371-4385. [PMID: 33744975 PMCID: PMC8096224 DOI: 10.1093/nar/gkab191] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/10/2021] [Accepted: 03/06/2021] [Indexed: 12/13/2022] Open
Abstract
Higher-order chromatin structure undergoes striking changes in response to various developmental and environmental signals, causing distinct cell types to adopt specific chromatin organization. High throughput chromatin conformation capture (Hi-C) allows studying higher-order chromatin structure; however, this technique requires substantial amounts of starting material, which has limited the establishment of cell type-specific higher-order chromatin structure in plants. To overcome this limitation, we established a protocol that is applicable to a limited amount of nuclei by combining the INTACT (isolation of nuclei tagged in specific cell types) method and Hi-C (INT-Hi-C). Using this INT-Hi-C protocol, we generated Hi-C data from INTACT purified endosperm and leaf nuclei. Our INT-Hi-C data from leaf accurately reiterated chromatin interaction patterns derived from conventional leaf Hi-C data. We found that the higher-order chromatin organization of mixed leaf tissues and endosperm differs and that DNA methylation and repressive histone marks positively correlate with the chromatin compaction level. We furthermore found that self-looped interacting genes have increased expression in leaves and endosperm and that interacting intergenic regions negatively impact on gene expression in the endosperm. Last, we identified several imprinted genes involved in long-range and trans interactions exclusively in endosperm. Our study provides evidence that the endosperm adopts a distinct higher-order chromatin structure that differs from other cell types in plants and that chromatin interactions influence transcriptional activity.
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Affiliation(s)
- Vikash Kumar Yadav
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant Biology, Uppsala 75007, Sweden
| | - Juan Santos-González
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant Biology, Uppsala 75007, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant Biology, Uppsala 75007, Sweden
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32
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Barbosa P, Schemczssen-Graeff Z, Marques A, da Silva M, Favero GM, Sobreiro BP, de Almeida MC, Moreira-Filho O, Silva DMZDA, Porto-Foresti F, Foresti F, Artoni RF. Silencing of Transposable Elements Mediated by 5-mC and Compensation of the Heterochromatin Content by Presence of B Chromosomes in Astyanax scabripinnis. Cells 2021; 10:1162. [PMID: 34064768 PMCID: PMC8151356 DOI: 10.3390/cells10051162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 01/21/2023] Open
Abstract
The way in which transcriptional activity overcomes the physical DNA structure and gene regulation mechanisms involves complex processes that are not yet fully understood. Modifications in the cytosine-guanine sequence of DNA by 5-mC are preferentially located in heterochromatic regions and are related to gene silencing. Herein, we investigate evidence of epigenetic regulation related to the B chromosome model and transposable elements in A. scabripinnis. Indirect immunofluorescence using anti-5-mC to mark methylated regions was employed along with quantitative ELISA to determine the total genomic DNA methylation level. 5-mC signals were dispersed in the chromosomes of both females and males, with preferential accumulation in the B chromosome. In addition to the heterochromatic methylated regions, our results suggest that methylation is associated with transposable elements (LINE and Tc1-Mariner). Heterochromatin content was measured based on the C-band length in relation to the size of chromosome 1. The B chromosome in A. scabripinnis comprises heterochromatin located in the pericentromeric region of both arms of this isochromosome. In this context, individuals with B chromosomes should have an increased heterochromatin content when compared to individuals that do not. Although, both heterochromatin content and genome methylation showed no significant differences between sexes or in relation to the occurrence of B chromosomes. Our evidence suggests that the B chromosome can have a compensation effect on the heterochromatin content and that methylation possibly operates to silence TEs in A. scabripinnis. This represents a sui generis compensation and gene activity buffering mechanism.
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Affiliation(s)
- Patrícia Barbosa
- Post Graduate Program in Evolutionary Genetics and Molecular Biology, Department of Genetics and Evolution, Federal University of São Carlos, Rodovia Washington Luís Km 235, São Carlos 13565-905, SP, Brazil; (P.B.); (O.M.-F.)
| | - Zelinda Schemczssen-Graeff
- Post Graduate Program in Evolutionary Biology, Department of Structural, Molecular and Genetic Biology, State University of Ponta Grossa, Avenida Carlos Cavalcanti 4748, Ponta Grossa 84030-900, PR, Brazil; (Z.S.-G.); (M.d.S.); (M.C.d.A.)
| | - André Marques
- Department of Botany, Federal University of Pernambuco, Recife 50670-901, PE, Brazil;
| | - Maelin da Silva
- Post Graduate Program in Evolutionary Biology, Department of Structural, Molecular and Genetic Biology, State University of Ponta Grossa, Avenida Carlos Cavalcanti 4748, Ponta Grossa 84030-900, PR, Brazil; (Z.S.-G.); (M.d.S.); (M.C.d.A.)
| | - Giovani Marino Favero
- Department of General Biology, State University of Ponta Grossa, Avenida Carlos Cavalcanti 4748, Ponta Grossa 84030-900, PR, Brazil;
| | - Bernardo Passos Sobreiro
- Department of Medicine, State University of Ponta Grossa, Avenida Carlos Cavalcanti 4748, Ponta Grossa 84030-900, PR, Brazil;
| | - Mara Cristina de Almeida
- Post Graduate Program in Evolutionary Biology, Department of Structural, Molecular and Genetic Biology, State University of Ponta Grossa, Avenida Carlos Cavalcanti 4748, Ponta Grossa 84030-900, PR, Brazil; (Z.S.-G.); (M.d.S.); (M.C.d.A.)
| | - Orlando Moreira-Filho
- Post Graduate Program in Evolutionary Genetics and Molecular Biology, Department of Genetics and Evolution, Federal University of São Carlos, Rodovia Washington Luís Km 235, São Carlos 13565-905, SP, Brazil; (P.B.); (O.M.-F.)
| | - Duílio Mazzoni Zerbinato de Andrade Silva
- Department of Structural and Functional Biology, Institute of Biosciences at Botucatu, Sao Paulo State University (UNESP), Botucatu 18618-689, SP, Brazil; (D.M.Z.d.A.S.); (F.F.)
| | - Fábio Porto-Foresti
- Faculty of Sciences, Sao Paulo State University (UNESP), Bauru 01049-010, SP, Brazil;
| | - Fausto Foresti
- Department of Structural and Functional Biology, Institute of Biosciences at Botucatu, Sao Paulo State University (UNESP), Botucatu 18618-689, SP, Brazil; (D.M.Z.d.A.S.); (F.F.)
| | - Roberto Ferreira Artoni
- Post Graduate Program in Evolutionary Genetics and Molecular Biology, Department of Genetics and Evolution, Federal University of São Carlos, Rodovia Washington Luís Km 235, São Carlos 13565-905, SP, Brazil; (P.B.); (O.M.-F.)
- Post Graduate Program in Evolutionary Biology, Department of Structural, Molecular and Genetic Biology, State University of Ponta Grossa, Avenida Carlos Cavalcanti 4748, Ponta Grossa 84030-900, PR, Brazil; (Z.S.-G.); (M.d.S.); (M.C.d.A.)
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33
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Dissecting Murine Muscle Stem Cell Aging through Regeneration Using Integrative Genomic Analysis. Cell Rep 2021; 32:107964. [PMID: 32726628 PMCID: PMC8025697 DOI: 10.1016/j.celrep.2020.107964] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 04/12/2020] [Accepted: 07/03/2020] [Indexed: 12/19/2022] Open
Abstract
During aging, there is a progressive loss of volume and function in skeletal muscle that impacts mobility and quality of life. The repair of skeletal muscle is regulated by tissue-resident stem cells called satellite cells (or muscle stem cells [MuSCs]), but in aging, MuSCs decrease in numbers and regenerative capacity. The transcriptional networks and epigenetic changes that confer diminished regenerative function in MuSCs as a result of natural aging are only partially understood. Herein, we use an integrative genomics approach to profile MuSCs from young and aged animals before and after injury. Integration of these datasets reveals aging impacts multiple regulatory changes through significant differences in gene expression, metabolic flux, chromatin accessibility, and patterns of transcription factor (TF) binding activities. Collectively, these datasets facilitate a deeper understanding of the regulation tissue-resident stem cells use during aging and healing.
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34
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Miriklis EL, Rozario AM, Rothenberg E, Bell TDM, Whelan DR. Understanding DNA organization, damage, and repair with super-resolution fluorescence microscopy. Methods Appl Fluoresc 2021; 9. [PMID: 33765677 DOI: 10.1088/2050-6120/abf239] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 03/25/2021] [Indexed: 11/12/2022]
Abstract
Super-resolution microscopy (SRM) comprises a suite of techniques well-suited to probing the nanoscale landscape of genomic function and dysfunction. Offering the specificity and sensitivity that has made conventional fluorescence microscopy a cornerstone technique of biological research, SRM allows for spatial resolutions as good as 10 nanometers. Moreover, single molecule localization microscopies (SMLMs) enable examination of individual molecular targets and nanofoci allowing for the characterization of subpopulations within a single cell. This review describes how key advances in both SRM techniques and sample preparation have enabled unprecedented insights into DNA structure and function, and highlights many of these new discoveries. Ongoing development and application of these novel, highly interdisciplinary SRM assays will continue to expand the toolbox available for research into the nanoscale genomic landscape.
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Affiliation(s)
| | | | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, United States of America
| | - Toby D M Bell
- School of Chemistry, Monash University, Clayton, VIC, Australia
| | - Donna R Whelan
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
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35
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Pongubala JMR, Murre C. Spatial Organization of Chromatin: Transcriptional Control of Adaptive Immune Cell Development. Front Immunol 2021; 12:633825. [PMID: 33854505 PMCID: PMC8039525 DOI: 10.3389/fimmu.2021.633825] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/03/2021] [Indexed: 12/11/2022] Open
Abstract
Higher-order spatial organization of the genome into chromatin compartments (permissive and repressive), self-associating domains (TADs), and regulatory loops provides structural integrity and offers diverse gene regulatory controls. In particular, chromatin regulatory loops, which bring enhancer and associated transcription factors in close spatial proximity to target gene promoters, play essential roles in regulating gene expression. The establishment and maintenance of such chromatin loops are predominantly mediated involving CTCF and the cohesin machinery. In recent years, significant progress has been made in revealing how loops are assembled and how they modulate patterns of gene expression. Here we will discuss the mechanistic principles that underpin the establishment of three-dimensional (3D) chromatin structure and how changes in chromatin structure relate to alterations in gene programs that establish immune cell fate.
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Affiliation(s)
| | - Cornelis Murre
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
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36
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Lee SY, Hung S, Esnault C, Pathak R, Johnson KR, Bankole O, Yamashita A, Zhang H, Levin HL. Dense Transposon Integration Reveals Essential Cleavage and Polyadenylation Factors Promote Heterochromatin Formation. Cell Rep 2021; 30:2686-2698.e8. [PMID: 32101745 PMCID: PMC9497450 DOI: 10.1016/j.celrep.2020.01.094] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 10/18/2019] [Accepted: 01/27/2020] [Indexed: 11/24/2022] Open
Abstract
Heterochromatin functions as a scaffold for factors responsible for gene
silencing and chromosome segregation. Heterochromatin can be assembled by
multiple pathways, including RNAi and RNA surveillance. We identified factors
that form heterochromatin using dense profiles of transposable element
integration in Schizosaccharomyces pombe. The candidates
include a large number of essential proteins such as four canonical mRNA
cleavage and polyadenylation factors. We find that Iss1, a subunit of the
poly(A) polymerase module, plays a role in forming heterochromatin in centromere
repeats that is independent of RNAi. Genome-wide maps reveal that Iss1
accumulates at genes regulated by RNA surveillance. Iss1 interacts with RNA
surveillance factors Mmi1 and Rrp6, and importantly, Iss1 contributes to RNA
elimination that forms heterochromatin at meiosis genes. Our profile of
transposable element integration supports the model that a network of mRNA
cleavage and polyadenylation factors coordinates RNA surveillance, including the
mechanism that forms heterochromatin at meiotic genes. Lee et al. use dense profiles of transposon integration to identify genes
important for the formation of heterochromatin. Among many candidates, Iss1 is a
canonical mRNA cleavage and polyadenylation factor found to be important for
heterochromatin at meiotic genes by recruiting the nuclear exosome.
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Affiliation(s)
- Si Young Lee
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stevephen Hung
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Caroline Esnault
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rakesh Pathak
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kory R Johnson
- Bioinformatics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Oluwadamilola Bankole
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Akira Yamashita
- National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Hongen Zhang
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Henry L Levin
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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Schistosoma mansoni Heterochromatin Protein 1 (HP1) nuclear interactome in cercariae. J Proteomics 2021; 239:104170. [PMID: 33662613 DOI: 10.1016/j.jprot.2021.104170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 11/21/2022]
Abstract
Schistosoma mansoni causes schistosomiasis, which affects 240 million people, and 700 million people are living at risk of infection. Epigenetic mechanisms are important for transcriptional control and are well-known conserved transcriptional co-regulators in evolution, already described in mammal, yeast, protozoa and S. mansoni, responsible for heterochromatization and gene silence mechanisms through the formation of complexes of transcriptional repression in chromatin. Previous results from another group have shown that HP1 (SmCBX) proteins form chromatin complexes with SmMDB2/3 proteins and regulate stem cells and oviposition in parasite adult worms. In addition, results from other groups have shown that cercariae are transcriptionally silent and epigenetic mechanisms are involved in the regulation of gene expression in this stage. In this work, our aim was to give insights into SmHP1 and proteins involved in transcriptional regulation in the cercariae stage. Using monoclonal anti-HP1 antibody for Western blotting, immunoprecipitation, and mass spectrometry, we preliminarily determined nuclear proteins that putatively interact with HP1 to form complexes to regulate gene expression, heterochromatin formation, and translational complexes in the cercariae stage. So far, our data is to give some insights into nuclear interactors in S. mansoni cercariae. SIGNIFICANCE: The significance of this original paper is the evidence for Heterochromatin Protein (HP1), interaction with nuclear proteins in the cercariae stage. Schistosoma mansoni cercariae are the infective stage of the human beings in endemic areas of schistosomiasis, a neglected disease, most prevalent in Brazil and Africa. While cercariae are waiting for a host, it does not feed, gene expression is silent and protein synthesis is stopped. These biochemical mechanisms are recovered when cercariae find a human host, but all proteins and mechanisms are not still elucidated. Until now, literature shows that these phenomena are regulated by epigenetics mechanisms, dependent of histone posttranslational modifications. But we have few pieces of evidence about the other proteins that participates in these processes and which are the co-regulators of expression.
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Local Rather than Global H3K27me3 Dynamics Are Associated with Differential Gene Expression in Verticillium dahliae. mBio 2021; 13:e0356621. [PMID: 35130723 PMCID: PMC8822345 DOI: 10.1128/mbio.03566-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Differential growth conditions typically trigger global transcriptional responses in filamentous fungi. Such fungal responses to environmental cues involve epigenetic regulation, including chemical histone modifications. It has been proposed that conditionally expressed genes, such as those that encode secondary metabolites but also effectors in pathogenic species, are often associated with a specific histone modification, lysine27 methylation of H3 (H3K27me3). However, thus far, no analyses on the global H3K27me3 profiles have been reported under differential growth conditions in order to assess if H3K27me3 dynamics govern differential transcription. Using chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing data from the plant-pathogenic fungus Verticillium dahliae grown in three in vitro cultivation media, we now show that a substantial number of the identified H3K27me3 domains globally display stable profiles among these growth conditions. However, we observe local quantitative differences in H3K27me3 ChIP-seq signals that are associated with a subset of differentially transcribed genes between media. Comparing the in vitro results to expression during plant infection suggests that in planta-induced genes may require chromatin remodeling to achieve expression. Overall, our results demonstrate that some loci display H3K27me3 dynamics associated with concomitant transcriptional variation, but many differentially expressed genes are associated with stable H3K27me3 domains. Thus, we conclude that while H3K27me3 is required for transcriptional repression, it does not appear that transcriptional activation requires the global erasure of H3K27me3. We propose that the H3K27me3 domains that do not undergo dynamic methylation may contribute to transcription through other mechanisms or may serve additional genomic regulatory functions. IMPORTANCE In many organisms, including filamentous fungi, epigenetic mechanisms that involve chemical and physical modifications of DNA without changing the genetic sequence have been implicated in transcriptional responses upon developmental or environmental cues. In fungi, facultative heterochromatin that can decondense to allow transcription in response to developmental changes or environmental stimuli is characterized by the trimethylation of lysine 27 on histone H3 (H3K27me3), and H3K27me3 has been implicated in transcriptional regulation, although the precise mechanisms and functions remain enigmatic. Based on ChIP and RNA sequencing data, we show for the soilborne broad-host-range vascular wilt plant-pathogenic fungus Verticillium dahliae that although some loci display H3K27me3 dynamics that can contribute to transcriptional variation, other loci do not show such a dependence. Thus, although we recognize that H3K27me3 is required for transcriptional repression, we also conclude that this mark is not a conditionally responsive global regulator of differential transcription upon responses to environmental cues.
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Bui HTN, Passecker A, Brancucci NMB, Voss TS. Investigation of Heterochromatin Protein 1 Function in the Malaria Parasite Plasmodium falciparum Using a Conditional Domain Deletion and Swapping Approach. mSphere 2021; 6:e01220-20. [PMID: 33536327 PMCID: PMC7860992 DOI: 10.1128/msphere.01220-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/15/2021] [Indexed: 12/12/2022] Open
Abstract
The human malaria parasite Plasmodium falciparum encodes a single ortholog of heterochromatin protein 1 (PfHP1) that plays a crucial role in the epigenetic regulation of various survival-related processes. PfHP1 is essential for parasite proliferation and the heritable silencing of genes linked to antigenic variation, host cell invasion, and sexual conversion. Here, we employed CRISPR/Cas9-mediated genome editing combined with the DiCre/loxP system to investigate how the PfHP1 chromodomain (CD), hinge domain, and chromoshadow domain (CSD) contribute to overall PfHP1 function. We show that the 76 C-terminal residues are responsible for targeting PfHP1 to the nucleus. Furthermore, we reveal that each of the three functional domains of PfHP1 are required for heterochromatin formation, gene silencing, and mitotic parasite proliferation. Finally, we discovered that the hinge domain and CSD of HP1 are functionally conserved between P. falciparum and P. berghei, a related malaria parasite infecting rodents. In summary, our study provides new insights into PfHP1 function and offers a tool for further studies on epigenetic regulation and life cycle decision in malaria parasites.IMPORTANCE Malaria is caused by unicellular Plasmodium species parasites that repeatedly invade and replicate inside red blood cells. Some blood-stage parasites exit the cell cycle and differentiate into gametocytes that are essential for malaria transmission via the mosquito vector. Epigenetic control mechanisms allow the parasites to alter the expression of surface antigens and to balance the switch between parasite multiplication and gametocyte production. These processes are crucial to establish chronic infection and optimize parasite transmission. Here, we performed a mutational analysis of heterochromatin protein 1 (HP1) in P. falciparum We demonstrate that all three domains of this protein are indispensable for the proper function of HP1 in parasite multiplication, heterochromatin formation, and gene silencing. Moreover, expression of chimeric proteins revealed the functional conservation of HP1 proteins between different Plasmodium species. These results provide new insight into the function and evolution of HP1 as an essential epigenetic regulator of parasite survival.
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Affiliation(s)
- Hai T N Bui
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Armin Passecker
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Nicolas M B Brancucci
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Till S Voss
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Bitman-Lotan E, Orian A. Nuclear organization and regulation of the differentiated state. Cell Mol Life Sci 2021; 78:3141-3158. [PMID: 33507327 PMCID: PMC8038961 DOI: 10.1007/s00018-020-03731-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 12/01/2020] [Accepted: 12/04/2020] [Indexed: 12/22/2022]
Abstract
Regulation of the differentiated identity requires active and continued supervision. Inability to maintain the differentiated state is a hallmark of aging and aging-related disease. To maintain cellular identity, a network of nuclear regulators is devoted to silencing previous and non-relevant gene programs. This network involves transcription factors, epigenetic regulators, and the localization of silent genes to heterochromatin. Together, identity supervisors mold and maintain the unique nuclear environment of the differentiated cell. This review describes recent discoveries regarding mechanisms and regulators that supervise the differentiated identity and protect from de-differentiation, tumorigenesis, and attenuate forced somatic cell reprograming. The review focuses on mechanisms involved in H3K9me3-decorated heterochromatin and the importance of nuclear lamins in cell identity. We outline how the biophysical properties of these factors are involved in self-compartmentalization of heterochromatin and cell identity. Finally, we discuss the relevance of these regulators to aging and age-related disease.
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Affiliation(s)
- Eliya Bitman-Lotan
- Rappaport Research Institute and Faculty of Medicine, The Rappaport Faculty of Medicine Technion-IIT, Technion Integrative Cancer Center (TICC), Technion-Israel Institute of Technology, Bat-Galim, 3109610, Haifa, Israel
| | - Amir Orian
- Rappaport Research Institute and Faculty of Medicine, The Rappaport Faculty of Medicine Technion-IIT, Technion Integrative Cancer Center (TICC), Technion-Israel Institute of Technology, Bat-Galim, 3109610, Haifa, Israel.
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41
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Zhang S, Yu X, Zhang Y, Xue X, Yu Q, Zha Z, Gogol M, Workman JL, Li S. Metabolic regulation of telomere silencing by SESAME complex-catalyzed H3T11 phosphorylation. Nat Commun 2021; 12:594. [PMID: 33500413 PMCID: PMC7838282 DOI: 10.1038/s41467-020-20711-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 12/11/2020] [Indexed: 02/07/2023] Open
Abstract
Telomeres are organized into a heterochromatin structure and maintenance of silent heterochromatin is required for chromosome stability. How telomere heterochromatin is dynamically regulated in response to stimuli remains unknown. Pyruvate kinase Pyk1 forms a complex named SESAME (Serine-responsive SAM-containing Metabolic Enzyme complex) to regulate gene expression by phosphorylating histone H3T11 (H3pT11). Here, we identify a function of SESAME in regulating telomere heterochromatin structure. SESAME phosphorylates H3T11 at telomeres, which maintains SIR (silent information regulator) complex occupancy at telomeres and protects Sir2 from degradation by autophagy. Moreover, SESAME-catalyzed H3pT11 directly represses autophagy-related gene expression to further prevent autophagy-mediated Sir2 degradation. By promoting H3pT11, serine increases Sir2 protein levels and enhances telomere silencing. Loss of H3pT11 leads to reduced Sir2 and compromised telomere silencing during chronological aging. Together, our study provides insights into dynamic regulation of silent heterochromatin by histone modifications and autophagy in response to cell metabolism and aging.
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Affiliation(s)
- Shihao Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, Hubei, 430062, China
| | - Xilan Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, Hubei, 430062, China
| | - Yuan Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, Hubei, 430062, China
| | - Xiangyan Xue
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, Hubei, 430062, China
| | - Qi Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, Hubei, 430062, China
| | - Zitong Zha
- Human Aging Research Institute (HARI), School of Life Science, Nanchang University, Nanchang, Jiangxi, 330031, China
| | - Madelaine Gogol
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO, 64110, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO, 64110, USA
| | - Shanshan Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, Hubei, 430062, China.
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Weigt M, Gao Q, Ban H, He H, Mastrobuoni G, Kempa S, Chen W, Li F. Rbm10 facilitates heterochromatin assembly via the Clr6 HDAC complex. Epigenetics Chromatin 2021; 14:8. [PMID: 33468217 PMCID: PMC7816512 DOI: 10.1186/s13072-021-00382-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 01/08/2021] [Indexed: 01/13/2023] Open
Abstract
Splicing factors have recently been shown to be involved in heterochromatin formation, but their role in controlling heterochromatin structure and function remains poorly understood. In this study, we identified a fission yeast homologue of human splicing factor RBM10, which has been linked to TARP syndrome. Overexpression of Rbm10 in fission yeast leads to strong global intron retention. Rbm10 also interacts with splicing factors in a pattern resembling that of human RBM10, suggesting that the function of Rbm10 as a splicing regulator is conserved. Surprisingly, our deep-sequencing data showed that deletion of Rbm10 caused only minor effect on genome-wide gene expression and splicing. However, the mutant displays severe heterochromatin defects. Further analyses indicated that the heterochromatin defects in the mutant did not result from mis-splicing of heterochromatin factors. Our proteomic data revealed that Rbm10 associates with the histone deacetylase Clr6 complex and chromatin remodelers known to be important for heterochromatin silencing. Deletion of Rbm10 results in significant reduction of Clr6 in heterochromatin. Our work together with previous findings further suggests that different splicing subunits may play distinct roles in heterochromatin regulation.
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Affiliation(s)
- Martina Weigt
- Laboratory for Functional Genomics and Systems Biology, Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, 13125, Berlin, Germany
| | - Qingsong Gao
- Laboratory for Functional Genomics and Systems Biology, Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, 13125, Berlin, Germany
| | - Hyoju Ban
- Department of Biology, New York University, New York, NY, 10003-6688, USA
| | - Haijin He
- Department of Biology, New York University, New York, NY, 10003-6688, USA
| | - Guido Mastrobuoni
- Integrative Metabolomics and Proteomics, Berlin Institute of Medical Systems Biology, Max-Delbrueck Center for Molecular Medicine, 13125, Berlin, Germany
| | - Stefan Kempa
- Integrative Metabolomics and Proteomics, Berlin Institute of Medical Systems Biology, Max-Delbrueck Center for Molecular Medicine, 13125, Berlin, Germany
| | - Wei Chen
- Laboratory for Functional Genomics and Systems Biology, Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, 13125, Berlin, Germany. .,Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China. .,Medi-X Institute, SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China.
| | - Fei Li
- Department of Biology, New York University, New York, NY, 10003-6688, USA.
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Feliciello I, Pezer Ž, Sermek A, Bruvo Mađarić B, Ljubić S, Ugarković Đ. Satellite DNA-Mediated Gene Expression Regulation: Physiological and Evolutionary Implication. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 60:145-167. [PMID: 34386875 DOI: 10.1007/978-3-030-74889-0_6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Satellite DNAs are tandemly repeated sequences organized in large clusters within (peri)centromeric and/or subtelomeric heterochromatin. However, in many species, satellite DNAs are not restricted to heterochromatin but are also dispersed as short arrays within euchromatin. Such genomic organization together with transcriptional activity seems to be a prerequisite for the gene-modulatory effect of satellite DNAs which was first demonstrated in the beetle Tribolium castaneum upon heat stress. Namely, enrichment of a silent histone mark at euchromatic repeats of a major beetle satellite DNA results in epigenetic silencing of neighboring genes. In addition, human satellite III transcripts induced by heat shock contribute to genome-wide gene silencing, providing protection against stress-induced cell death. Gene silencing mediated by satellite RNA was also shown to be fundamental for the early embryonic development of the mosquito Aedes aegypti. Apart from a physiological role during embryogenesis and heat stress response, activation of satellite DNAs in terms of transcription and proliferation can have an evolutionary impact. Spreading of satellite repeats throughout euchromatin promotes the variation of epigenetic landscapes and gene expression diversity, contributing to the evolution of gene regulatory networks and to genome adaptation in fluctuating environmental conditions.
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Affiliation(s)
- Isidoro Feliciello
- Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia.,Dipartimento di Medicina Clinica e Chirurgia, Universita' degli Studi di Napoli Federico II, Naples, Italy
| | - Željka Pezer
- Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Antonio Sermek
- Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | | | - Sven Ljubić
- Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Đurđica Ugarković
- Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia.
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Giardini MC, Nieves M, Scannapieco AC, Conte CA, Milla FH, Schapovaloff ME, Frissolo MS, Remis MI, Cladera JL, Lanzavecchia SB. Geographic distribution of sex chromosome polymorphism in Anastrepha fraterculus sp. 1 from Argentina. BMC Genet 2020; 21:149. [PMID: 33339514 PMCID: PMC7747450 DOI: 10.1186/s12863-020-00944-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Anastrepha fraterculus is recognized as a quarantine pest in several American countries. This fruit fly species is native to the American continent and distributed throughout tropical and subtropical regions. It has been reported as a complex of cryptic species, and at least eight morphotypes have been described. Only one entity of this complex, formerly named Anastrepha fraterculus sp. 1, is present in Argentina. Previous cytogenetic studies on this morphotype described the presence of sex chromosome variation identified by chromosomal size and staining patterns. In this work, we expanded the cytological study of this morphotype by analyzing laboratory strains and wild populations to provide information about the frequency and geographic distribution of these sex chromosome variants. We analyzed the mitotic metaphases of individuals from four laboratory strains and five wild populations from the main fruit-producing areas of Argentina, including the northwest (Tucumán and La Rioja), northeast (Entre Ríos and Misiones), and center (Buenos Aires) of the country. RESULTS In wild samples, we observed a high frequency of X1X1 (0.94) and X1Y5 (0.93) karyomorphs, whereas X1X2 and X1Y6 were exclusively found at a low frequency in Buenos Aires (0.07 and 0.13, respectively), Entre Ríos (0.16 and 0.14, respectively) and Tucumán (0.03 and 0.04, respectively). X2X2 and X2Y5 karyomorphs were not found in wild populations but were detected at a low frequency in laboratory strains. In fact, karyomorph frequencies differed between wild populations and laboratory strains. No significant differences among A. fraterculus wild populations were evidenced in either karyotypic or chromosomal frequencies. However, a significant correlation was observed between Y5 chromosomal frequency and latitude. CONCLUSIONS We discuss the importance of cytogenetics to understand the possible route of invasion and dispersion of this pest in Argentina and the evolutionary forces acting under laboratory conditions, possibly driving changes in the chromosomal frequencies. Our findings provide deep and integral genetic knowledge of this species, which has become of relevance to the characterization and selection of valuable A. fraterculus sp. 1 strains for mass rearing production and SIT implementation.
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Affiliation(s)
- María Cecilia Giardini
- Laboratorio de Insectos de Importancia Agronómica, Instituto de Genética (IGEAF), Instituto de Agrobiotecnología y Biología Molecular (IABIMO), INTA- CONICET, Hurlingham, Buenos Aires, Argentina
| | - Mariela Nieves
- Grupo de Investigación en Biología Evolutiva, Departamento de Ecología, Genética y Evolución, IEGEBA (CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alejandra Carla Scannapieco
- Laboratorio de Insectos de Importancia Agronómica, Instituto de Genética (IGEAF), Instituto de Agrobiotecnología y Biología Molecular (IABIMO), INTA- CONICET, Hurlingham, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Claudia Alejandra Conte
- Laboratorio de Insectos de Importancia Agronómica, Instituto de Genética (IGEAF), Instituto de Agrobiotecnología y Biología Molecular (IABIMO), INTA- CONICET, Hurlingham, Buenos Aires, Argentina
| | - Fabián Horacio Milla
- Laboratorio de Insectos de Importancia Agronómica, Instituto de Genética (IGEAF), Instituto de Agrobiotecnología y Biología Molecular (IABIMO), INTA- CONICET, Hurlingham, Buenos Aires, Argentina
| | - María Elena Schapovaloff
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Estación Experimental Agropecuaria Montecarlo, Instituto Nacional de Tecnología Agropecuaria (INTA), Misiones, Argentina
| | - Maria Soledad Frissolo
- Subprograma La Rioja, Programa Nacional de Control y Erradicación de Moscas de los Frutos (PROCEM), La Rioja, Argentina
| | - María Isabel Remis
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Genética de la Estructura Poblacional, Departamento de Ecología, Genética y Evolución,IEGEBA (CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jorge Luis Cladera
- Laboratorio de Insectos de Importancia Agronómica, Instituto de Genética (IGEAF), Instituto de Agrobiotecnología y Biología Molecular (IABIMO), INTA- CONICET, Hurlingham, Buenos Aires, Argentina
| | - Silvia Beatriz Lanzavecchia
- Laboratorio de Insectos de Importancia Agronómica, Instituto de Genética (IGEAF), Instituto de Agrobiotecnología y Biología Molecular (IABIMO), INTA- CONICET, Hurlingham, Buenos Aires, Argentina
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Biomolecular condensates as arbiters of biochemical reactions inside the nucleus. Commun Biol 2020; 3:773. [PMID: 33319830 PMCID: PMC7738674 DOI: 10.1038/s42003-020-01517-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/24/2020] [Indexed: 12/20/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) has emerged as a central player in the assembly of membraneless compartments termed biomolecular condensates. These compartments are dynamic structures that can condense or dissolve under specific conditions to regulate molecular functions. Such properties allow biomolecular condensates to rapidly respond to changing endogenous or environmental conditions. Here, we review emerging roles for LLPS within the nuclear space, with a specific emphasis on genome organization, expression and repair. Our review highlights the emerging notion that biomolecular condensates regulate the sequential engagement of molecules in multistep biological processes. Laflamme and Mekhail discuss emerging nuclear roles for LLPS in genome organization, gene expression and DNA repair, highlighting the emerging notion that biomolecular condensates regulate the sequential engagement of molecules in multistep biological processes.
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Karyotype Evolution in 10 Pinniped Species: Variability of Heterochromatin versus High Conservatism of Euchromatin as Revealed by Comparative Molecular Cytogenetics. Genes (Basel) 2020; 11:genes11121485. [PMID: 33321928 PMCID: PMC7763226 DOI: 10.3390/genes11121485] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/04/2020] [Accepted: 12/04/2020] [Indexed: 11/19/2022] Open
Abstract
Pinnipedia karyotype evolution was studied here using human, domestic dog, and stone marten whole-chromosome painting probes to obtain comparative chromosome maps among species of Odobenidae (Odobenus rosmarus), Phocidae (Phoca vitulina, Phoca largha, Phoca hispida, Pusa sibirica, Erignathus barbatus), and Otariidae (Eumetopias jubatus, Callorhinus ursinus, Phocarctos hookeri, and Arctocephalus forsteri). Structural and functional chromosomal features were assessed with telomere repeat and ribosomal-DNA probes and by CBG (C-bands revealed by barium hydroxide treatment followed by Giemsa staining) and CDAG (Chromomycin A3-DAPI after G-banding) methods. We demonstrated diversity of heterochromatin among pinniped karyotypes in terms of localization, size, and nucleotide composition. For the first time, an intrachromosomal rearrangement common for Otariidae and Odobenidae was revealed. We postulate that the order of evolutionarily conserved segments in the analyzed pinnipeds is the same as the order proposed for the ancestral Carnivora karyotype (2n = 38). The evolution of conserved genomes of pinnipeds has been accompanied by few fusion events (less than one rearrangement per 10 million years) and by novel intrachromosomal changes including the emergence of new centromeres and pericentric inversion/centromere repositioning. The observed interspecific diversity of pinniped karyotypes driven by constitutive heterochromatin variation likely has played an important role in karyotype evolution of pinnipeds, thereby contributing to the differences of pinnipeds’ chromosome sets.
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Kalinka A, Achrem M. The distribution pattern of 5-methylcytosine in rye (Secale L.) chromosomes. PLoS One 2020; 15:e0240869. [PMID: 33057421 PMCID: PMC7561101 DOI: 10.1371/journal.pone.0240869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 10/04/2020] [Indexed: 12/02/2022] Open
Abstract
The rye (Secale L.) genome is large, and it contains many classes of repetitive sequences. Secale species differ in terms of genome size, heterochromatin content, and global methylation level; however, the organization of individual types of sequences in chromosomes is relatively similar. The content of the abundant subtelomeric heterochromatin fraction in rye do not correlate with the global level of cytosine methylation, hence immunofluorescence detection of 5-methylcytosine (5-mC) distribution in metaphase chromosomes was performed. The distribution patterns of 5-methylcytosine in the chromosomes of Secale species/subspecies were generally similar. 5-methylcytosine signals were dispersed along the entire length of the chromosome arms of all chromosomes, indicating high levels of methylation, especially at retrotransposon sequences. 5-mC signals were absent in the centromeric and telomeric regions, as well as in subtelomeric blocks of constitutive heterochromatin, in each of the taxa studied. Pericentromeric domains were methylated, however, there was a certain level of polymorphism in these areas, as was the case with the nucleolus organizer region. Sequence methylation within the region of the heterochromatin intercalary bands were also demonstrated to be heterogenous. Unexpectedly, there was a lack of methylation in rye subtelomeres, indicating that heterochromatin is a very diverse fraction of chromatin, and its epigenetic regulation or potential influence on adjacent regions can be more complex than has conventionally been thought. Like telomeres and centromeres, subtelomeric heterochromatin can has a specific role, and the absence of 5-mC is required to maintain the heterochromatin state.
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Affiliation(s)
- Anna Kalinka
- Institute of Biology, University of Szczecin, Szczecin, Poland
- Molecular Biology and Biotechnology Center, University of Szczecin, Szczecin, Poland
- * E-mail:
| | - Magdalena Achrem
- Institute of Biology, University of Szczecin, Szczecin, Poland
- Molecular Biology and Biotechnology Center, University of Szczecin, Szczecin, Poland
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Abstract
Gene expression is needed for the maintenance of heart function under normal conditions and in response to stress. Each cell type of the heart has a specific program controlling transcription. Different types of stress induce modifications of these programs and, if prolonged, can lead to altered cardiac phenotype and, eventually, to heart failure. The transcriptional status of a gene is regulated by the epigenome, a complex network of DNA and histone modifications. Until a few years ago, our understanding of the role of the epigenome in heart disease was limited to that played by histone deacetylation. But over the last decade, the consequences for the maintenance of homeostasis in the heart and for the development of cardiac hypertrophy of a number of other modifications, including DNA methylation and hydroxymethylation, histone methylation and acetylation, and changes in chromatin architecture, have become better understood. Indeed, it is now clear that many levels of regulation contribute to defining the epigenetic landscape required for correct cardiomyocyte function, and that their perturbation is responsible for cardiac hypertrophy and fibrosis. Here, we review these aspects and draw a picture of what epigenetic modification may imply at the therapeutic level for heart failure.
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Affiliation(s)
- Roberto Papait
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy; Humanitas Clinical Research Center-IRCCS, Rozzano, Italy; Humanitas University, Department of Biomedical Sciences, Pieve Emanuele, Italy; and National Research Council of Italy, Institute of Genetics and Biomedical Research, Milan Unit, Rozzano, Italy
| | - Simone Serio
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy; Humanitas Clinical Research Center-IRCCS, Rozzano, Italy; Humanitas University, Department of Biomedical Sciences, Pieve Emanuele, Italy; and National Research Council of Italy, Institute of Genetics and Biomedical Research, Milan Unit, Rozzano, Italy
| | - Gianluigi Condorelli
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy; Humanitas Clinical Research Center-IRCCS, Rozzano, Italy; Humanitas University, Department of Biomedical Sciences, Pieve Emanuele, Italy; and National Research Council of Italy, Institute of Genetics and Biomedical Research, Milan Unit, Rozzano, Italy
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Meluzzi D, Arya G. Computational approaches for inferring 3D conformations of chromatin from chromosome conformation capture data. Methods 2020; 181-182:24-34. [PMID: 31470090 PMCID: PMC7044057 DOI: 10.1016/j.ymeth.2019.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/24/2019] [Accepted: 08/23/2019] [Indexed: 02/08/2023] Open
Abstract
Chromosome conformation capture (3C) and its variants are powerful experimental techniques for probing intra- and inter-chromosomal interactions within cell nuclei at high resolution and in a high-throughput, quantitative manner. The contact maps derived from such experiments provide an avenue for inferring the 3D spatial organization of the genome. This review provides an overview of the various computational methods developed in the past decade for addressing the very important but challenging problem of deducing the detailed 3D structure or structure population of chromosomal domains, chromosomes, and even entire genomes from 3C contact maps.
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Affiliation(s)
- Dario Meluzzi
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, United States
| | - Gaurav Arya
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708, United States.
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50
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Ropa J, Saha N, Hu H, Peterson LF, Talpaz M, Muntean AG. SETDB1 mediated histone H3 lysine 9 methylation suppresses MLL-fusion target expression and leukemic transformation. Haematologica 2020; 105:2273-2285. [PMID: 33054052 PMCID: PMC7556517 DOI: 10.3324/haematol.2019.223883] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 09/25/2019] [Indexed: 11/23/2022] Open
Abstract
Epigenetic regulators play a critical role in normal and malignant hematopoiesis. Deregulation, including epigenetic deregulation, of the HOXA gene cluster drives transformation of about 50% of acute myeloid leukemia. We recently showed that the Histone 3 Lysine 9 methyltransferase SETDB1 negatively regulates the expression of the pro-leukemic genes Hoxa9 and its cofactor Meis1 through deposition of promoter H3K9 trimethylation in MLL-AF9 leukemia cells. Here, we investigated the biological impact of altered SETDB1 expression and changes in H3K9 methylation on acute myeloid leukemia. We demonstrate that SETDB1 expression is correlated to disease status and overall survival in acute myeloid leukemia patients. We recapitulated these findings in mice, where high expression of SETDB1 delayed MLL-AF9 mediated disease progression by promoting differentiation of leukemia cells. We also explored the biological impact of treating normal and malignant hematopoietic cells with an H3K9 methyltransferase inhibitor, UNC0638. While myeloid leukemia cells demonstrate cytotoxicity to UNC0638 treatment, normal bone marrow cells exhibit an expansion of cKit+ hematopoietic stem and progenitor cells. Consistent with these data, we show that bone marrow treated with UNC0638 is more amenable to transformation by MLL-AF9. Next generation sequencing of leukemia cells shows that high expression of SETDB1 induces repressive changes to the promoter epigenome and downregulation of genes linked with acute myeloid leukemia, including Dock1 and the MLL-AF9 target genes Hoxa9, Six1, and others. These data reveal novel targets of SETDB1 in leukemia that point to a role for SETDB1 in negatively regulating pro-leukemic target genes and suppressing acute myeloid leukemia.
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Affiliation(s)
- James Ropa
- Department of Pathology, University of Michigan Medical School
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School
| | - Nirmalya Saha
- Department of Pathology, University of Michigan Medical School
| | - Hsiangyu Hu
- Department of Pathology, University of Michigan Medical School
| | - Luke F. Peterson
- Department of Internal Medicine/Division of Hematology/Oncology, University of Michigan School of Medicine and Comprehensive Cancer Center, Ann Abor, MI, USA
| | - Moshe Talpaz
- Department of Internal Medicine/Division of Hematology/Oncology, University of Michigan School of Medicine and Comprehensive Cancer Center, Ann Abor, MI, USA
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