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Ayhan DH, Abbondante S, Martínez-Soto D, Milo S, Rickelton K, Sohrab V, Kotera S, Arie T, Marshall ME, Rocha MC, Haridas S, Grigoriev IV, Shlezinger N, Pearlman E, Ma LJ. The differential virulence of Fusarium strains causing corneal infections and plant diseases is associated with accessory chromosome composition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.23.595639. [PMID: 38826335 PMCID: PMC11142239 DOI: 10.1101/2024.05.23.595639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Fusarium oxysporum is a cross-kingdom pathogen. While some strains cause disseminated fusariosis and blinding corneal infections in humans, others are responsible for devastating vascular wilt diseases in plants. To better understand the distinct adaptations of F. oxysporum to animal or plant hosts, we conducted a comparative phenotypic and genetic analysis of two strains: MRL8996 (isolated from a keratitis patient) and Fol4287 (isolated from a wilted tomato [Solanum lycopersicum]). In vivo infection of mouse corneas and tomato plants revealed that, while both strains cause symptoms in both hosts, MRL8996 caused more severe corneal ulceration and perforation in mice, whereas Fol4287 induced more pronounced wilting symptoms in tomato. In vitro assays using abiotic stress treatments revealed that the human pathogen MRL8996 was better adapted to elevated temperatures, whereas the plant pathogen Fol4287 was more tolerant of osmotic and cell wall stresses. Both strains displayed broad resistance to antifungal treatment, with MRL8996 exhibiting the paradoxical effect of increased tolerance to higher concentrations of the antifungal caspofungin. We identified a set of accessory chromosomes (ACs) and protein-encoding genes with distinct transposon profiles and functions, respectively, between MRL8996 and Fol4287. Interestingly, ACs from both genomes also encode proteins with shared functions, such as chromatin remodeling and post-translational protein modifications. Our phenotypic assays and comparative genomics analyses lay the foundation for future studies correlating genotype with phenotype and for developing targeted antifungals for agricultural and clinical uses.
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Affiliation(s)
- Dilay Hazal Ayhan
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Serena Abbondante
- Physiology and Biophysics and Ophthalmology, University of California, Irvine, USA University of Massachusetts Amherst, Amherst, MA, USA
| | - Domingo Martínez-Soto
- Department of Microbiology, Centro de Investigación Científica y Educación Superior de Ensenada (CICESE), Ensenada, Baja California, Mexico
| | - Shira Milo
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Katherine Rickelton
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Vista Sohrab
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Shunsuke Kotera
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Tokyo, Japan
| | - Tsutomu Arie
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Tokyo, Japan
| | - Michaela Ellen Marshall
- Physiology and Biophysics and Ophthalmology, University of California, Irvine, USA University of Massachusetts Amherst, Amherst, MA, USA
| | - Marina Campos Rocha
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sajeet Haridas
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Neta Shlezinger
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eric Pearlman
- Physiology and Biophysics and Ophthalmology, University of California, Irvine, USA University of Massachusetts Amherst, Amherst, MA, USA
| | - Li-Jun Ma
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA, USA
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2
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Phan TM, Kim YC, Debelouchina GT, Mittal J. Interplay between charge distribution and DNA in shaping HP1 paralog phase separation and localization. eLife 2024; 12:RP90820. [PMID: 38592759 PMCID: PMC11003746 DOI: 10.7554/elife.90820] [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: 04/10/2024] Open
Abstract
The heterochromatin protein 1 (HP1) family is a crucial component of heterochromatin with diverse functions in gene regulation, cell cycle control, and cell differentiation. In humans, there are three paralogs, HP1α, HP1β, and HP1γ, which exhibit remarkable similarities in their domain architecture and sequence properties. Nevertheless, these paralogs display distinct behaviors in liquid-liquid phase separation (LLPS), a process linked to heterochromatin formation. Here, we employ a coarse-grained simulation framework to uncover the sequence features responsible for the observed differences in LLPS. We highlight the significance of the net charge and charge patterning along the sequence in governing paralog LLPS propensities. We also show that both highly conserved folded and less-conserved disordered domains contribute to the observed differences. Furthermore, we explore the potential co-localization of different HP1 paralogs in multicomponent assemblies and the impact of DNA on this process. Importantly, our study reveals that DNA can significantly reshape the stability of a minimal condensate formed by HP1 paralogs due to competitive interactions of HP1α with HP1β and HP1γ versus DNA. In conclusion, our work highlights the physicochemical nature of interactions that govern the distinct phase-separation behaviors of HP1 paralogs and provides a molecular framework for understanding their role in chromatin organization.
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Affiliation(s)
- Tien M Phan
- Artie McFerrin Department of Chemical Engineering, Texas A&M UniversityCollege StationUnited States
| | - Young C Kim
- Center for Materials Physics and Technology, Naval Research LaboratoryWashingtonUnited States
| | - Galia T Debelouchina
- Department of Chemistry and Biochemistry, University of California, San DiegoLa JollaUnited States
| | - Jeetain Mittal
- Artie McFerrin Department of Chemical Engineering, Texas A&M UniversityCollege StationUnited States
- Department of Chemistry, Texas A&M UniversityCollege StationUnited States
- Interdisciplinary Graduate Program in Genetics and Genomics, Texas A&M UniversityCollege StationUnited States
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3
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Phan TM, Kim YC, Debelouchina GT, Mittal J. Interplay between charge distribution and DNA in shaping HP1 paralog phase separation and localization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.28.542535. [PMID: 37398008 PMCID: PMC10312469 DOI: 10.1101/2023.05.28.542535] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The heterochromatin protein 1 (HP1) family is a crucial component of heterochromatin with diverse functions in gene regulation, cell cycle control, and cell differentiation. In humans, there are three paralogs, HP1α, HP1β, and HP1γ, which exhibit remarkable similarities in their domain architecture and sequence properties. Nevertheless, these paralogs display distinct behaviors in liquid-liquid phase separation (LLPS), a process linked to heterochromatin formation. Here, we employ a coarse-grained simulation framework to uncover the sequence features responsible for the observed differences in LLPS. We highlight the significance of the net charge and charge patterning along the sequence in governing paralog LLPS propensities. We also show that both highly conserved folded and less-conserved disordered domains contribute to the observed differences. Furthermore, we explore the potential co-localization of different HP1 paralogs in multicomponent assemblies and the impact of DNA on this process. Importantly, our study reveals that DNA can significantly reshape the stability of a minimal condensate formed by HP1 paralogs due to competitive interactions of HP1α with HP1β and HP1γ versus DNA. In conclusion, our work highlights the physicochemical nature of interactions that govern the distinct phase-separation behaviors of HP1 paralogs and provides a molecular framework for understanding their role in chromatin organization.
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Affiliation(s)
- Tien M. Phan
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Young C. Kim
- Center for Materials Physics and Technology, Naval Research Laboratory, Washington, DC, USA
| | - Galia T. Debelouchina
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| | - Jeetain Mittal
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
- Department of Chemistry, Texas A&M University, College Station, TX, USA
- Interdisciplinary Graduate Program in Genetics and Genomics, Texas A&M University, College Station, TX, USA
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4
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Nishitani A, Hiramatsu K, Kadooka C, Mori K, Okutsu K, Yoshizaki Y, Takamine K, Tashiro K, Goto M, Tamaki H, Futagami T. Expression of heterochromatin protein 1 affects citric acid production in Aspergillus luchuensis mut. kawachii. J Biosci Bioeng 2023; 136:443-451. [PMID: 37775438 DOI: 10.1016/j.jbiosc.2023.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 08/17/2023] [Accepted: 09/07/2023] [Indexed: 10/01/2023]
Abstract
A putative methyltransferase, LaeA, controls citric acid production through epigenetic regulation of the citrate exporter gene, cexA, in the white koji fungus Aspergillus luchuensis mut. kawachii. In this study, we investigated the role of another epigenetic regulator, heterochromatin protein 1, HepA, in citric acid production. The ΔhepA strain exhibited reduced citric acid production in liquid culture, although to a lesser extent compared to the ΔlaeA strain. In addition, the ΔlaeA ΔhepA strain showed citric acid production similar to the ΔlaeA strain, indicating that HepA plays a role in citric acid production, albeit with a less-significant regulatory effect than LaeA. RNA-seq analysis revealed that the transcriptomic profiles of the ΔhepA and ΔlaeA strains were similar, and the expression level of cexA was reduced in both strains. These findings suggest that the genes regulated by HepA are similar to those regulated by LaeA in A. luchuensis mut. kawachii. However, the reductions in citric acid production and cexA expression observed in the disruptants were mitigated in rice koji, a solid-state culture. Thus, the mechanism by which citric acid production is regulated differs between liquid and solid cultivation. Further investigation is thus needed to understand the regulatory mechanism in koji.
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Affiliation(s)
- Atsushi Nishitani
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Center for Advanced Science Research and Promotion, Kagoshima University, Kagoshima 890-0065, Japan
| | - Kentaro Hiramatsu
- Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan
| | - Chihiro Kadooka
- Department of Biotechnology and Life Sciences, Faculty of Biotechnology and Life Sciences, Sojo University, Kumamoto 860-0082, Japan
| | - Kazuki Mori
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Kayu Okutsu
- Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Yumiko Yoshizaki
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Kazunori Takamine
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Kosuke Tashiro
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Masatoshi Goto
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga 840-8502, Japan
| | - Hisanori Tamaki
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Taiki Futagami
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan.
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5
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Yu Y, Wang S, Wang Z, Gao R, Lee J. Arabidopsis thaliana: a powerful model organism to explore histone modifications and their upstream regulations. Epigenetics 2023; 18:2211362. [PMID: 37196184 DOI: 10.1080/15592294.2023.2211362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 04/07/2023] [Accepted: 04/28/2023] [Indexed: 05/19/2023] Open
Abstract
Histones are subjected to extensive covalent modifications that affect inter-nucleosomal interactions as well as alter chromatin structure and DNA accessibility. Through switching the corresponding histone modifications, the level of transcription and diverse downstream biological processes can be regulated. Although animal systems are widely used in studying histone modifications, the signalling processes that occur outside the nucleus prior to histone modifications have not been well understood due to the limitations including non viable mutants, partial lethality, and infertility of survivors. Here, we review the benefits of using Arabidopsis thaliana as the model organism to study histone modifications and their upstream regulations. Similarities among histones and key histone modifiers such as the Polycomb group (PcG) and Trithorax group (TrxG) in Drosophila, Human, and Arabidopsis are examined. Furthermore, prolonged cold-induced vernalization system has been well-studied and revealed the relationship between the controllable environment input (duration of vernalization), its chromatin modifications of FLOWERING LOCUS C (FLC), following gene expression, and the corresponding phenotypes. Such evidence suggests that research on Arabidopsis can bring insights into incomplete signalling pathways outside of the histone box, which can be achieved through viable reverse genetic screenings based on the phenotypes instead of direct monitoring of histone modifications among individual mutants. The potential upstream regulators in Arabidopsis can provide cues or directions for animal research based on the similarities between them.
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Affiliation(s)
- Yang Yu
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
| | - Sihan Wang
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
| | - Ziqin Wang
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
| | - Renwei Gao
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
| | - Joohyun Lee
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
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6
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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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7
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Seman M, Levashkevich A, Larkin A, Huang F, Ragunathan K. Uncoupling the distinct functions of HP1 proteins during heterochromatin establishment and maintenance. Cell Rep 2023; 42:113428. [PMID: 37952152 DOI: 10.1016/j.celrep.2023.113428] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 09/28/2023] [Accepted: 10/26/2023] [Indexed: 11/14/2023] Open
Abstract
H3K9 methylation (H3K9me) marks transcriptionally silent genomic regions called heterochromatin. HP1 proteins are required to establish and maintain heterochromatin. HP1 proteins bind to H3K9me, recruit factors that promote heterochromatin formation, and oligomerize to form phase-separated condensates. We do not understand how these different HP1 properties are involved in establishing and maintaining transcriptional silencing. Here, we demonstrate that the S. pombe HP1 homolog, Swi6, can be completely bypassed to establish silencing at ectopic and endogenous loci when an H3K4 methyltransferase, Set1, and an H3K14 acetyltransferase, Mst2, are deleted. Deleting Set1 and Mst2 enhances Clr4 enzymatic activity, leading to higher H3K9me levels and spreading. In contrast, Swi6 and its capacity to oligomerize were indispensable during epigenetic maintenance. Our results demonstrate the role of HP1 proteins in regulating histone modification crosstalk during establishment and identify a genetically separable function in maintaining epigenetic memory.
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Affiliation(s)
- Melissa Seman
- Department of Biology, Brandeis University, Waltham, MA 02451, USA
| | | | - Ajay Larkin
- Department of Biology, Brandeis University, Waltham, MA 02451, USA
| | - Fengting Huang
- Department of Biology, Brandeis University, Waltham, MA 02451, USA
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8
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Li B. Telomere maintenance in African trypanosomes. Front Mol Biosci 2023; 10:1302557. [PMID: 38074093 PMCID: PMC10704157 DOI: 10.3389/fmolb.2023.1302557] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/15/2023] [Indexed: 02/12/2024] Open
Abstract
Telomere maintenance is essential for genome integrity and chromosome stability in eukaryotic cells harboring linear chromosomes, as telomere forms a specialized structure to mask the natural chromosome ends from DNA damage repair machineries and to prevent nucleolytic degradation of the telomeric DNA. In Trypanosoma brucei and several other microbial pathogens, virulence genes involved in antigenic variation, a key pathogenesis mechanism essential for host immune evasion and long-term infections, are located at subtelomeres, and expression and switching of these major surface antigens are regulated by telomere proteins and the telomere structure. Therefore, understanding telomere maintenance mechanisms and how these pathogens achieve a balance between stability and plasticity at telomere/subtelomere will help develop better means to eradicate human diseases caused by these pathogens. Telomere replication faces several challenges, and the "end replication problem" is a key obstacle that can cause progressive telomere shortening in proliferating cells. To overcome this challenge, most eukaryotes use telomerase to extend the G-rich telomere strand. In addition, a number of telomere proteins use sophisticated mechanisms to coordinate the telomerase-mediated de novo telomere G-strand synthesis and the telomere C-strand fill-in, which has been extensively studied in mammalian cells. However, we recently discovered that trypanosomes lack many telomere proteins identified in its mammalian host that are critical for telomere end processing. Rather, T. brucei uses a unique DNA polymerase, PolIE that belongs to the DNA polymerase A family (E. coli DNA PolI family), to coordinate the telomere G- and C-strand syntheses. In this review, I will first briefly summarize current understanding of telomere end processing in mammals. Subsequently, I will describe PolIE-mediated coordination of telomere G- and C-strand synthesis in T. brucei and implication of this recent discovery.
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Affiliation(s)
- Bibo Li
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Arts and Sciences, Cleveland State University, Cleveland, OH, United States
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, United States
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, OH, United States
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9
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González J, Bosch-Presegué L, Marazuela-Duque A, Guitart-Solanes A, Espinosa-Alcantud M, Fernandez AF, Brown JP, Ausió J, Vazquez BN, Singh PB, Fraga MF, Vaquero A. A complex interplay between H2A.Z and HP1 isoforms regulates pericentric heterochromatin. Front Cell Dev Biol 2023; 11:1293122. [PMID: 38020886 PMCID: PMC10665487 DOI: 10.3389/fcell.2023.1293122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Pericentric heterochromatin (PCH) plays an essential role in the maintenance of genome integrity and alterations in PCH have been linked to cancer and aging. HP1 α, β, and γ, are hallmarks of constitutive heterochromatin that are thought to promote PCH structure through binding to heterochromatin-specific histone modifications and interaction with a wide range of factors. Among the less understood components of PCH is the histone H2A variant H2A.Z, whose role in the organization and maintenance of PCH is poorly defined. Here we show that there is a complex interplay between H2A.Z and HP1 isoforms in PCH. While the loss of HP1α results in the accumulation of H2A.Z.1 in PCH, which is associated with a significant decrease in its mobile fraction, H2A.Z.1 binds preferentially to HP1β in these regions. Of note, H2A.Z.1 downregulation results in increased heterochromatinization and instability of PCH, reflected by accumulation of the major epigenetic hallmarks of heterochromatin in these regions and increased frequency of chromosome aberrations related to centromeric/pericentromeric defects. Our studies support a role for H2A.Z in genome stability and unveil a key role of H2A.Z in the regulation of heterochromatin-specific epigenetic modifications through a complex interplay with the HP1 isoforms.
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Affiliation(s)
- Jessica González
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
| | - Laia Bosch-Presegué
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
- Tissue Repair and Regeneration Laboratory (TR2Lab), Institut de Recerca I Innovació en Ciències de La Vida i de La Salut a La Catalunya Central (IrisCC), Barcelona, Spain
| | - Anna Marazuela-Duque
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
| | - Anna Guitart-Solanes
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
| | - María Espinosa-Alcantud
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
| | - Agustín F. Fernandez
- Nanomaterials and Nanotechnology Research Center (CINN), Spanish National Research Council (CSIC), El Entrego, Spain
- Institute of Oncology of Asturias (IUOPA), University of Oviedo, Oviedo, Spain
- Health Research Institute of the Principality of Asturias (ISPA), Oviedo, Spain
- Spanish Biomedical Research Network in Rare Diseases (CIBERER), Madrid, Spain
| | - Jeremy P. Brown
- Department of Immunology and Inflammation, Imperial College London, Commonwealth Building, The Hammersmith Hospital, London, United Kingdom
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Berta N. Vazquez
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
- Cytology and Histology Unit. Department of Cell Biology, Physiology, and Immunology, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Prim B. Singh
- Nazarbayev University School of Medicine, Astana, Kazakhstan
| | - Mario F. Fraga
- Nanomaterials and Nanotechnology Research Center (CINN), Spanish National Research Council (CSIC), El Entrego, Spain
- Institute of Oncology of Asturias (IUOPA), University of Oviedo, Oviedo, Spain
- Health Research Institute of the Principality of Asturias (ISPA), Oviedo, Spain
- Spanish Biomedical Research Network in Rare Diseases (CIBERER), Madrid, Spain
| | - Alejandro Vaquero
- Chromatin Biology Laboratory, Josep Carreras Leukaemia Research Institute (IJC), Barcelona, Spain
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10
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Seman M, Levashkevich A, Larkin A, Huang F, Ragunathan K. Uncoupling the distinct functions of HP1 proteins during heterochromatin establishment and maintenance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.30.538869. [PMID: 37961629 PMCID: PMC10634687 DOI: 10.1101/2023.04.30.538869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
H3K9 methylation (H3K9me) marks transcriptionally silent genomic regions called heterochromatin. HP1 proteins are required to establish and maintain heterochromatin. HP1 proteins bind to H3K9me, recruit factors that promote heterochromatin formation, and oligomerize to form phase-separated condensates. We do not understand how HP1 protein binding to heterochromatin establishes and maintains transcriptional silencing. Here, we demonstrate that the S.pombe HP1 homolog, Swi6, can be completely bypassed to establish silencing at ectopic and endogenous loci when an H3K4 methyltransferase, Set1 and an H3K14 acetyltransferase, Mst2 are deleted. Deleting Set1 and Mst2 enhances Clr4 enzymatic activity, leading to higher H3K9me levels and spreading. In contrast, Swi6 and its capacity to oligomerize were indispensable during epigenetic maintenance. Our results demonstrate the role of HP1 proteins in regulating histone modification crosstalk during establishment and identifies a genetically separable function in maintaining epigenetic memory.
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Affiliation(s)
- Melissa Seman
- Department of Biology, Brandeis University, Waltham, MA 02451 USA
| | | | - Ajay Larkin
- Department of Biology, Brandeis University, Waltham, MA 02451 USA
| | - Fengting Huang
- Department of Biology, Brandeis University, Waltham, MA 02451 USA
| | - Kaushik Ragunathan
- Department of Biology, Brandeis University, Waltham, MA 02451 USA
- Lead Contact
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11
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Lee GE, Byun J, Lee CJ, Cho YY. Molecular Mechanisms for the Regulation of Nuclear Membrane Integrity. Int J Mol Sci 2023; 24:15497. [PMID: 37895175 PMCID: PMC10607757 DOI: 10.3390/ijms242015497] [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: 09/26/2023] [Revised: 10/19/2023] [Accepted: 10/22/2023] [Indexed: 10/29/2023] Open
Abstract
The nuclear membrane serves a critical role in protecting the contents of the nucleus and facilitating material and signal exchange between the nucleus and cytoplasm. While extensive research has been dedicated to topics such as nuclear membrane assembly and disassembly during cell division, as well as interactions between nuclear transmembrane proteins and both nucleoskeletal and cytoskeletal components, there has been comparatively less emphasis on exploring the regulation of nuclear morphology through nuclear membrane integrity. In particular, the role of type II integral proteins, which also function as transcription factors, within the nuclear membrane remains an area of research that is yet to be fully explored. The integrity of the nuclear membrane is pivotal not only during cell division but also in the regulation of gene expression and the communication between the nucleus and cytoplasm. Importantly, it plays a significant role in the development of various diseases. This review paper seeks to illuminate the biomolecules responsible for maintaining the integrity of the nuclear membrane. It will delve into the mechanisms that influence nuclear membrane integrity and provide insights into the role of type II membrane protein transcription factors in this context. Understanding these aspects is of utmost importance, as it can offer valuable insights into the intricate processes governing nuclear membrane integrity. Such insights have broad-reaching implications for cellular function and our understanding of disease pathogenesis.
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Affiliation(s)
- Ga-Eun Lee
- BK21-4th, and BRL, College of Pharmacy, The Catholic University of Korea, 43, Jibong-ro, Wonmi-gu, Bucheon-si 14662, Gyeonggi-do, Republic of Korea; (G.-E.L.); (J.B.)
| | - Jiin Byun
- BK21-4th, and BRL, College of Pharmacy, The Catholic University of Korea, 43, Jibong-ro, Wonmi-gu, Bucheon-si 14662, Gyeonggi-do, Republic of Korea; (G.-E.L.); (J.B.)
| | - Cheol-Jung Lee
- Research Center for Materials Analysis, Korea Basic Science Institute, 169-148, Gwahak-ro, Yuseong-gu, Daejeon 34133, Chungcheongnam-do, Republic of Korea
| | - Yong-Yeon Cho
- BK21-4th, and BRL, College of Pharmacy, The Catholic University of Korea, 43, Jibong-ro, Wonmi-gu, Bucheon-si 14662, Gyeonggi-do, Republic of Korea; (G.-E.L.); (J.B.)
- RCD Control and Material Research Institute, The Catholic University of Korea, 43, Jibong-ro, Wonmi-gu, Bucheon-si 14662, Gyeonggi-do, Republic of Korea
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Papamokos GV, Kaxiras E. How to evict HP1 from H3: Using a complex salt bridge. Biophys Chem 2023; 300:107062. [PMID: 37302360 DOI: 10.1016/j.bpc.2023.107062] [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: 04/26/2023] [Revised: 05/21/2023] [Accepted: 06/03/2023] [Indexed: 06/13/2023]
Abstract
In an effort to unravel the unknown "binary switch" mechanisms underlying the "histone code" hypothesis of gene silencing and activation, we study the dynamics of Heterochromatin Protein 1 (HP1). We find in the literature that when HP1 is bound to tri-methylated Lysine9 (K9me3) of histone-H3 through an aromatic cage consisting of two tyrosines and one tryptophan, it is evicted upon phosphorylation of Serine10 (S10phos) during mitosis. In this work, the kick-off intermolecular interaction of the eviction process is proposed and described in detail on the basis of quantum mechanical calculations: specifically, an electrostatic interaction competes with the cation-π interaction and draws away K9me3 from the aromatic cage. An arginine, abundant in the histonic environment, can form an intermolecular "complex salt bridge" with S10phos and dislodge HP1. The study attempts to reveal the role of phosphorylation of Ser10 on the H3 tail in atomic detail.
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Affiliation(s)
- George V Papamokos
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138, USA..
| | - Efthimios Kaxiras
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138, USA..
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Doan PTB, Nio K, Shimakami T, Kuroki K, Li YY, Sugimoto S, Takayama H, Okada H, Kaneko S, Honda M, Yamashita T. Super-Resolution Microscopy Analysis of Hepatitis B Viral cccDNA and Host Factors. Viruses 2023; 15:v15051178. [PMID: 37243264 DOI: 10.3390/v15051178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/13/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
Infection with hepatitis B virus (HBV) cannot be cured completely because of the persistence of covalently closed circular DNA (cccDNA). We previously found that the host gene dedicator of cytokinesis 11 (DOCK11) was required for HBV persistence. In this study, we further investigated the mechanism that links DOCK11 to other host genes in the regulation of cccDNA transcription. cccDNA levels were determined by quantitative real-time polymerase chain reaction (qPCR) and fluorescence in situ hybridization (FISH) in stable HBV-producing cell lines and HBV-infected PXB-cells®. Interactions between DOCK11 and other host genes were identified by super-resolution microscopy, immunoblotting, and chromatin immunoprecipitation. FISH facilitated the subcellular localization of key HBV nucleic acids. Interestingly, although DOCK11 partially colocalized with histone proteins, such as H3K4me3 and H3K27me3, and nonhistone proteins, such as RNA Pol II, it played limited roles in histone modification and RNA transcription. DOCK11 was functionally involved in regulating the subnuclear distribution of host factors and/or cccDNA, resulting in an increase in cccDNA closely located to H3K4me3 and RNA Pol II for activating cccDNA transcription. Thus, it was suggested that the association of cccDNA-bound Pol II and H3K4me3 required the assistance of DOCK11. DOCK11 facilitated the association of cccDNA with H3K4me3 and RNA Pol II.
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Affiliation(s)
- Phuong Thi Bich Doan
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Kouki Nio
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Tetsuro Shimakami
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Kazuyuki Kuroki
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Ying-Yi Li
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Saiho Sugimoto
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Hideo Takayama
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Hikari Okada
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Shuichi Kaneko
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Masao Honda
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
| | - Taro Yamashita
- Department of Gastroenterology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa 920-8641, Japan
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Endogenous Retroviral Sequences Behave as Putative Enhancers Controlling Gene Expression through HP1-Regulated Long-Range Chromatin Interactions. Cells 2022; 11:cells11152392. [PMID: 35954237 PMCID: PMC9368123 DOI: 10.3390/cells11152392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 07/25/2022] [Accepted: 08/02/2022] [Indexed: 02/01/2023] Open
Abstract
About half of the mammalian genome is constituted of repeated elements, among which endogenous retroviruses (ERVs) are known to influence gene expression and cancer development. The HP1 (Heterochromatin Protein 1) proteins are known to be essential for heterochromatin establishment and function and its loss in hepatocytes leads to the reactivation of specific ERVs and to liver tumorigenesis. Here, by studying two ERVs located upstream of genes upregulated upon loss of HP1, Mbd1 and Trim24, we show that these HP1-dependent ERVs behave as either alternative promoters or as putative enhancers forming a loop with promoters of endogenous genes depending on the genomic context and HP1 expression level. These ERVs are characterised by a specific HP1-independent enrichment in heterochromatin-associated marks H3K9me3 and H4K20me3 as well as in the enhancer-specific mark H3K4me1, a combination that might represent a bookmark of putative ERV-derived enhancers. These ERVs are further enriched in a HP1-dependent manner in H3K27me3, suggesting a critical role of this mark together with HP1 in the silencing of the ERVs, as well as for the repression of the associated genes. Altogether, these results lead to the identification of a new regulatory hub involving the HP1-dependent formation of a physical loop between specific ERVs and endogenous genes.
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