1
|
Flipphi M, Harispe ML, Hamari Z, Kocsubé S, Scazzocchio C, Ramón A. An ascomycete H4 variant with an unknown function. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231705. [PMID: 38384781 PMCID: PMC10878826 DOI: 10.1098/rsos.231705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/22/2024] [Indexed: 02/23/2024]
Abstract
Histone variants leading to altered nucleosome structure, dynamics and DNA accessibility occur frequently, albeit rarely for H4. We carried out a comprehensive in silico scrutiny of fungal genomes, which revealed the presence of a novel H4 variant (H4E) in the ascomycetes, throughout the Pezizomycotina, in basal species of the Taphrinomycotina and also in the Glomeromycota. The coding cognate genes show a specific intron/exon organization, different from H4 canonical genes. H4Es diverge from canonical H4s mainly in the N- and C-terminal extensions, showing marked differences in the distribution and number of Lys and Arg residues, which may result in novel post-translational modifications. In Aspergillus nidulans (Pezizomycotina, Eurotiomycetes) the H4E variant protein level is low in mycelia. However, the encoding gene is well expressed at 37°C under nitrogen starvation. H4E localizes to the nucleus and interacts with H3, but its absence or overexpression does not result in any detectable phenotype. Deletion of only one of the of the two canonical H4 genes results in a strikingly impaired growth phenotype, which indicates that H4E cannot replace this canonical histone. Thus, an H4 variant is present throughout a whole subphylum of the ascomycetes, but with hitherto no experimentally detectable function.
Collapse
Affiliation(s)
- Michel Flipphi
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - María Laura Harispe
- Instituto de Profesores Artigas, Consejo de Formación en Educación (CFE, ANEP), Uruguay
| | - Zsuzsanna Hamari
- Faculty of Science and Informatics, Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Sándor Kocsubé
- Faculty of Science and Informatics, Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Claudio Scazzocchio
- Department of Life Sciences, Imperial College London, London, UK
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette 91198, France
| | - Ana Ramón
- Dpto. de Biología Celular y Molecular, Facultad de Ciencias, Sección Bioquímica, UdelaR, Uruguay
| |
Collapse
|
2
|
Ferraro AR, Ameri AJ, Lu Z, Kamei M, Schmitz RJ, Lewis ZA. Chromatin accessibility profiling in Neurospora crassa reveals molecular features associated with accessible and inaccessible chromatin. BMC Genomics 2021; 22:459. [PMID: 34147068 PMCID: PMC8214302 DOI: 10.1186/s12864-021-07774-0] [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: 10/25/2020] [Accepted: 06/04/2021] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Regulation of chromatin accessibility and transcription are tightly coordinated processes. Studies in yeast and higher eukaryotes have described accessible chromatin regions, but little work has been done in filamentous fungi. RESULTS Here we present a genome-scale characterization of accessible chromatin regions in Neurospora crassa, which revealed characteristic molecular features of accessible and inaccessible chromatin. We present experimental evidence of inaccessibility within heterochromatin regions in Neurospora, and we examine features of both accessible and inaccessible chromatin, including the presence of histone modifications, types of transcription, transcription factor binding, and relative nucleosome turnover rates. Chromatin accessibility is not strictly correlated with expression level. Accessible chromatin regions in the model filamentous fungus Neurospora are characterized the presence of H3K27 acetylation and commonly associated with pervasive non-coding transcription. Conversely, methylation of H3 lysine-36 catalyzed by ASH1 is correlated with inaccessible chromatin within promoter regions. CONCLUSIONS In N. crassa, H3K27 acetylation is the most predictive histone modification for open chromatin. Conversely, our data show that H3K36 methylation is a key marker of inaccessible chromatin in gene-rich regions of the genome. Our data are consistent with an expanded role for H3K36 methylation in intergenic regions of filamentous fungi compared to the model yeasts, S. cerevisiae and S. pombe, which lack homologs of the ASH1 methyltransferase.
Collapse
Affiliation(s)
- Aileen R Ferraro
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA
| | - Abigail J Ameri
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA
| | - Zefu Lu
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Masayuki Kamei
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Zachary A Lewis
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA.
| |
Collapse
|
3
|
IMITATION SWITCH is required for normal chromatin structure and gene repression in PRC2 target domains. Proc Natl Acad Sci U S A 2021; 118:2010003118. [PMID: 33468665 DOI: 10.1073/pnas.2010003118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Polycomb Group (PcG) proteins are part of an epigenetic cell memory system that plays essential roles in multicellular development, stem cell biology, X chromosome inactivation, and cancer. In animals, plants, and many fungi, Polycomb Repressive Complex 2 (PRC2) catalyzes trimethylation of histone H3 lysine 27 (H3K27me3) to assemble transcriptionally repressed facultative heterochromatin. PRC2 is structurally and functionally conserved in the model fungus Neurospora crassa, and recent work in this organism has generated insights into PRC2 control and function. To identify components of the facultative heterochromatin pathway, we performed a targeted screen of Neurospora deletion strains lacking individual ATP-dependent chromatin remodeling enzymes. We found the Neurospora homolog of IMITATION SWITCH (ISW) is critical for normal transcriptional repression, nucleosome organization, and establishment of typical histone methylation patterns in facultative heterochromatin domains. We also found that stable interaction between PRC2 and chromatin depends on ISW. A functional ISW ATPase domain is required for gene repression and normal H3K27 methylation. ISW homologs interact with accessory proteins to form multiple complexes with distinct functions. Using proteomics and molecular approaches, we identified three distinct Neurospora ISW-containing complexes. A triple mutant lacking three ISW accessory factors and disrupting multiple ISW complexes led to widespread up-regulation of PRC2 target genes and altered H3K27 methylation patterns, similar to an ISW-deficient strain. Taken together, our data show that ISW is a key component of the facultative heterochromatin pathway in Neurospora, and that distinct ISW complexes perform an apparently overlapping role to regulate chromatin structure and gene repression at PRC2 target domains.
Collapse
|
4
|
McKnight LE, Crandall JG, Bailey TB, Banks OGB, Orlandi KN, Truong VN, Donovan DA, Waddell GL, Wiles ET, Hansen SD, Selker EU, McKnight JN. Rapid and inexpensive preparation of genome-wide nucleosome footprints from model and non-model organisms. STAR Protoc 2021; 2:100486. [PMID: 34041500 PMCID: PMC8141940 DOI: 10.1016/j.xpro.2021.100486] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
MNase-seq (micrococcal nuclease sequencing) is used to map nucleosome positions in eukaryotic genomes to study the relationship between chromatin structure and DNA-dependent processes. Current protocols require at least two days to isolate nucleosome-protected DNA fragments. We have developed a streamlined protocol for S. cerevisiae and other fungi which takes only three hours. Modified protocols were developed for wild fungi and mammalian cells. This method for rapidly producing sequencing-ready nucleosome footprints from several organisms makes MNase-seq faster and easier, with less chemical waste. A fast way to prepare micrococcal nuclease nucleosome footprints for MNase-seq Eliminates use of phenol and chloroform and reduces the amount of cells required Adaptable for a variety of organisms
Collapse
Affiliation(s)
- Laura E McKnight
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | | | - Thomas B Bailey
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Orion G B Banks
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Kona N Orlandi
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Vi N Truong
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Drake A Donovan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Grace L Waddell
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Elizabeth T Wiles
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Scott D Hansen
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Eric U Selker
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Jeffrey N McKnight
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| |
Collapse
|
5
|
Seidl MF, Kramer HM, Cook DE, Fiorin GL, van den Berg GCM, Faino L, Thomma BPHJ. Repetitive Elements Contribute to the Diversity and Evolution of Centromeres in the Fungal Genus Verticillium. mBio 2020; 11:e01714-20. [PMID: 32900804 PMCID: PMC7482064 DOI: 10.1128/mbio.01714-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/05/2020] [Indexed: 02/07/2023] Open
Abstract
Centromeres are chromosomal regions that are crucial for chromosome segregation during mitosis and meiosis, and failed centromere formation can contribute to chromosomal anomalies. Despite this conserved function, centromeres differ significantly between and even within species. Thus far, systematic studies into the organization and evolution of fungal centromeres remain scarce. In this study, we identified the centromeres in each of the 10 species of the fungal genus Verticillium and characterized their organization and evolution. Chromatin immunoprecipitation of the centromere-specific histone CenH3 (ChIP-seq) and chromatin conformation capture (Hi-C) followed by high-throughput sequencing identified eight conserved, large (∼150-kb), AT-, and repeat-rich regional centromeres that are embedded in heterochromatin in the plant pathogen Verticillium dahliae Using Hi-C, we similarly identified repeat-rich centromeres in the other Verticillium species. Strikingly, a single degenerated long terminal repeat (LTR) retrotransposon is strongly associated with centromeric regions in some but not all Verticillium species. Extensive chromosomal rearrangements occurred during Verticillium evolution, of which some could be linked to centromeres, suggesting that centromeres contributed to chromosomal evolution. The size and organization of centromeres differ considerably between species, and centromere size was found to correlate with the genome-wide repeat content. Overall, our study highlights the contribution of repetitive elements to the diversity and rapid evolution of centromeres within the fungal genus VerticilliumIMPORTANCE The genus Verticillium contains 10 species of plant-associated fungi, some of which are notorious pathogens. Verticillium species evolved by frequent chromosomal rearrangements that contribute to genome plasticity. Centromeres are instrumental for separation of chromosomes during mitosis and meiosis, and failed centromere functionality can lead to chromosomal anomalies. Here, we used a combination of experimental techniques to identify and characterize centromeres in each of the Verticillium species. Intriguingly, we could strongly associate a single repetitive element to the centromeres of some of the Verticillium species. The presence of this element in the centromeres coincides with increased centromere sizes and genome-wide repeat expansions. Collectively, our findings signify a role of repetitive elements in the function, organization, and rapid evolution of centromeres in a set of closely related fungal species.
Collapse
Affiliation(s)
- Michael F Seidl
- Theoretical Biology & Bioinformatics, Utrecht University, Utrecht, the Netherlands
- Laboratory of Phytopathology, Wageningen University, Wageningen, the Netherlands
| | - H Martin Kramer
- Laboratory of Phytopathology, Wageningen University, Wageningen, the Netherlands
| | - David E Cook
- Laboratory of Phytopathology, Wageningen University, Wageningen, the Netherlands
- Plant Pathology, Kansas State University, Manhattan, Kansas, USA
| | - Gabriel L Fiorin
- Laboratory of Phytopathology, Wageningen University, Wageningen, the Netherlands
| | | | - Luigi Faino
- Laboratory of Phytopathology, Wageningen University, Wageningen, the Netherlands
- Environmental Biology Department, Sapienza Università di Roma, Rome, Italy
| | - Bart P H J Thomma
- Laboratory of Phytopathology, Wageningen University, Wageningen, the Netherlands
- University of Cologne, Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), Cologne, Germany
| |
Collapse
|
6
|
Courtney AJ, Kamei M, Ferraro AR, Gai K, He Q, Honda S, Lewis ZA. Normal Patterns of Histone H3K27 Methylation Require the Histone Variant H2A.Z in Neurospora crassa. Genetics 2020; 216:51-66. [PMID: 32651262 PMCID: PMC7463285 DOI: 10.1534/genetics.120.303442] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 07/05/2020] [Indexed: 12/14/2022] Open
Abstract
Neurospora crassa contains a minimal Polycomb repression system, which provides rich opportunities to explore Polycomb-mediated repression across eukaryotes and enables genetic studies that can be difficult in plant and animal systems. Polycomb Repressive Complex 2 is a multi-subunit complex that deposits mono-, di-, and trimethyl groups on lysine 27 of histone H3, and trimethyl H3K27 is a molecular marker of transcriptionally repressed facultative heterochromatin. In mouse embryonic stem cells and multiple plant species, H2A.Z has been found to be colocalized with H3K27 methylation. H2A.Z is required for normal H3K27 methylation in these experimental systems, though the regulatory mechanisms are not well understood. We report here that Neurospora crassa mutants lacking H2A.Z or SWR-1, the ATP-dependent histone variant exchanger, exhibit a striking reduction in levels of H3K27 methylation. RNA-sequencing revealed downregulation of eed, encoding a subunit of PRC2, in an hH2Az mutant compared to wild type, and overexpression of EED in a ΔhH2Az;Δeed background restored most H3K27 methylation. Reduced eed expression leads to region-specific losses of H3K27 methylation, suggesting that differential dependence on EED concentration is critical for normal H3K27 methylation at certain regions in the genome.
Collapse
Affiliation(s)
- Abigail J Courtney
- Department of Microbiology, University of Georgia, Athens, Georgia 30602
| | - Masayuki Kamei
- Department of Microbiology, University of Georgia, Athens, Georgia 30602
| | - Aileen R Ferraro
- Department of Microbiology, University of Georgia, Athens, Georgia 30602
| | - Kexin Gai
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Qun He
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Shinji Honda
- Division of Chromosome Biology, Faculty of Medical Sciences, University of Fukui, 910-1193, Japan
| | - Zachary A Lewis
- Department of Microbiology, University of Georgia, Athens, Georgia 30602
| |
Collapse
|
7
|
DNA Methylation and Histone H1 Jointly Repress Transposable Elements and Aberrant Intragenic Transcripts. Mol Cell 2020; 77:310-323.e7. [DOI: 10.1016/j.molcel.2019.10.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 08/26/2019] [Accepted: 10/10/2019] [Indexed: 12/12/2022]
|
8
|
Rutowicz K, Lirski M, Mermaz B, Teano G, Schubert J, Mestiri I, Kroteń MA, Fabrice TN, Fritz S, Grob S, Ringli C, Cherkezyan L, Barneche F, Jerzmanowski A, Baroux C. Linker histones are fine-scale chromatin architects modulating developmental decisions in Arabidopsis. Genome Biol 2019; 20:157. [PMID: 31391082 PMCID: PMC6685187 DOI: 10.1186/s13059-019-1767-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 07/21/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Chromatin provides a tunable platform for gene expression control. Besides the well-studied core nucleosome, H1 linker histones are abundant chromatin components with intrinsic potential to influence chromatin function. Well studied in animals, little is known about the evolution of H1 function in other eukaryotic lineages for instance plants. Notably, in the model plant Arabidopsis, while H1 is known to influence heterochromatin and DNA methylation, its contribution to transcription, molecular, and cytological chromatin organization remains elusive. RESULTS We provide a multi-scale functional study of Arabidopsis linker histones. We show that H1-deficient plants are viable yet show phenotypes in seed dormancy, flowering time, lateral root, and stomata formation-complemented by either or both of the major variants. H1 depletion also impairs pluripotent callus formation. Fine-scale chromatin analyses combined with transcriptome and nucleosome profiling reveal distinct roles of H1 on hetero- and euchromatin: H1 is necessary to form heterochromatic domains yet dispensable for silencing of most transposable elements; H1 depletion affects nucleosome density distribution and mobility in euchromatin, spatial arrangement of nanodomains, histone acetylation, and methylation. These drastic changes affect moderately the transcription but reveal a subset of H1-sensitive genes. CONCLUSIONS H1 variants have a profound impact on the molecular and spatial (nuclear) chromatin organization in Arabidopsis with distinct roles in euchromatin and heterochromatin and a dual causality on gene expression. Phenotypical analyses further suggest the novel possibility that H1-mediated chromatin organization may contribute to the epigenetic control of developmental and cellular transitions.
Collapse
Affiliation(s)
- Kinga Rutowicz
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
| | - Maciej Lirski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland
| | - Benoît Mermaz
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
- Department of Molecular, Cellular & Developmental Biology, Yale University, 352a Osborn memorial laboratories, New Haven, CT, 06511, USA
| | - Gianluca Teano
- Département de Biologie, IBENS, Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 46 rue d'Ulm, F-75005, Paris, France
| | - Jasmin Schubert
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
| | - Imen Mestiri
- Département de Biologie, IBENS, Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 46 rue d'Ulm, F-75005, Paris, France
| | - Magdalena A Kroteń
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, 02-089, Warsaw, Poland
| | - Tohnyui Ndinyanka Fabrice
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
| | - Simon Fritz
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
| | - Stefan Grob
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
| | - Christoph Ringli
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
| | - Lusik Cherkezyan
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Fredy Barneche
- Département de Biologie, IBENS, Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 46 rue d'Ulm, F-75005, Paris, France
| | - Andrzej Jerzmanowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland.
- Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106, Warsaw, Poland.
| | - Célia Baroux
- Institute of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland.
| |
Collapse
|
9
|
He S, Vickers M, Zhang J, Feng X. Natural depletion of histone H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation. eLife 2019; 8:42530. [PMID: 31135340 PMCID: PMC6594752 DOI: 10.7554/elife.42530] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 05/26/2019] [Indexed: 01/09/2023] Open
Abstract
Transposable elements (TEs), the movement of which can damage the genome, are epigenetically silenced in eukaryotes. Intriguingly, TEs are activated in the sperm companion cell - vegetative cell (VC) - of the flowering plant Arabidopsis thaliana. However, the extent and mechanism of this activation are unknown. Here we show that about 100 heterochromatic TEs are activated in VCs, mostly by DEMETER-catalyzed DNA demethylation. We further demonstrate that DEMETER access to some of these TEs is permitted by the natural depletion of linker histone H1 in VCs. Ectopically expressed H1 suppresses TEs in VCs by reducing DNA demethylation and via a methylation-independent mechanism. We demonstrate that H1 is required for heterochromatin condensation in plant cells and show that H1 overexpression creates heterochromatic foci in the VC progenitor cell. Taken together, our results demonstrate that the natural depletion of H1 during male gametogenesis facilitates DEMETER-directed DNA demethylation, heterochromatin relaxation, and TE activation.
Collapse
Affiliation(s)
- Shengbo He
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Martin Vickers
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Jingyi Zhang
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Xiaoqi Feng
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| |
Collapse
|
10
|
Nucleosome Positioning by an Evolutionarily Conserved Chromatin Remodeler Prevents Aberrant DNA Methylation in Neurospora. Genetics 2018; 211:563-578. [PMID: 30554169 DOI: 10.1534/genetics.118.301711] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 12/11/2018] [Indexed: 01/04/2023] Open
Abstract
In the filamentous fungus Neurospora crassa, constitutive heterochromatin is marked by tri-methylation of histone H3 lysine 9 (H3K9me3) and DNA methylation. We identified mutations in the Neurospora defective in methylation-1 (dim-1) gene that cause defects in cytosine methylation and implicate a putative AAA-ATPase chromatin remodeler. Although it was well-established that chromatin remodelers can affect transcription by influencing DNA accessibility with nucleosomes, little was known about the role of remodelers on chromatin that is normally not transcribed, including regions of constitutive heterochromatin. We found that dim-1 mutants display both reduced DNA methylation in heterochromatic regions as well as increased DNA methylation and H3K9me3 in some intergenic regions associated with highly expressed genes. Deletion of dim-1 leads to atypically spaced nucleosomes throughout the genome and numerous changes in gene expression. DIM-1 localizes to both heterochromatin and intergenic regions that become hyper-methylated in dim-1 strains. Our findings indicate that DIM-1 normally positions nucleosomes in both heterochromatin and euchromatin and that the standard arrangement and density of nucleosomes is required for the proper function of heterochromatin machinery.
Collapse
|
11
|
Liu X, Dang Y, Matsu-Ura T, He Y, He Q, Hong CI, Liu Y. DNA Replication Is Required for Circadian Clock Function by Regulating Rhythmic Nucleosome Composition. Mol Cell 2017. [PMID: 28648778 DOI: 10.1016/j.molcel.2017.05.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Although the coupling between circadian and cell cycles allows circadian clocks to gate cell division and DNA replication in many organisms, circadian clocks were thought to function independently of cell cycle. Here, we show that DNA replication is required for circadian clock function in Neurospora. Genetic and pharmacological inhibition of DNA replication abolished both overt and molecular rhythmicities by repressing frequency (frq) gene transcription. DNA replication is essential for the rhythmic changes of nucleosome composition at the frq promoter. The FACT complex, known to be involved in histone disassembly/reassembly, is required for clock function and is recruited to the frq promoter in a replication-dependent manner to promote replacement of histone H2A.Z by H2A. Finally, deletion of H2A.Z uncoupled the dependence of the circadian clock on DNA replication. Together, these results establish circadian clock and cell cycle as interdependent coupled oscillators and identify DNA replication as a critical process in the circadian mechanism.
Collapse
Affiliation(s)
- Xiao Liu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Yunkun Dang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Toru Matsu-Ura
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Yubo He
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA; Department of Biochemistry and Cell Biology, McMurtry College, Rice University, Houston, TX 77005, USA
| | - Qun He
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Christian I Hong
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Yi Liu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA.
| |
Collapse
|
12
|
Zhao Y, Ding J, Yuan W, Huang J, Huang W, Wang Y, Zheng W. Production of a fungal furocoumarin by a polyketide synthase gene cluster confers the chemo-resistance of Neurospora crassa to the predation by fungivorous arthropods. Environ Microbiol 2017; 19:3920-3929. [PMID: 28485098 DOI: 10.1111/1462-2920.13791] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 12/25/2022]
Abstract
The formation of sexual fruiting bodies and production of polyketides are believed to be the most important strategies for fungal survival in environmental insults. In Neurospora crassa, the backbone gene of polyketide synthase gene cluster 6 (pks-6), which is expressed at lower level under vegetative growth, is highly expressed during perithecia development. Intriguingly, deletion of pks-6 does not affect perithecia maturation. How the expression of pks-6 correlates with fungal sexual development remains to be established. Here, we showed that overexpression of pks-6 results in an enhanced production of an insecticidal furocoumarin (neurosporin A). Deletion of pks-6, however, abolished neurosporin A biosynthesis. Moreover, the content of neurosporin A negatively associates with the food preference of fungivores, where the pks-6 knockout strain is more prone to be grazed by collembolans Sinella curviseta. Additionally, during vegetative growth, confrontation with Drosophila melanogaster also results in an enhanced expression of pks-6 and production of neurosporin A. Thus, high expression of pks-6 positively interrelates with the chemo-resistance of N. crassa to arthropod predation. Our findings suggest that pks-6 confers the production of insecticidal neurosporin A counteracting the feeding attack by arthropods during sexual development of N. crassa.
Collapse
Affiliation(s)
- Yanxia Zhao
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Jianing Ding
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Weihua Yuan
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Jinjin Huang
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Wenxiu Huang
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Yan Wang
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Weifa Zheng
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| |
Collapse
|