51
|
Zhang T, Wei G, Millard CJ, Fischer R, Konietzny R, Kessler BM, Schwabe JWR, Brockdorff N. A variant NuRD complex containing PWWP2A/B excludes MBD2/3 to regulate transcription at active genes. Nat Commun 2018; 9:3798. [PMID: 30228260 PMCID: PMC6143588 DOI: 10.1038/s41467-018-06235-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 08/03/2018] [Indexed: 02/07/2023] Open
Abstract
Transcriptional regulation by chromatin is a highly dynamic process directed through the recruitment and coordinated action of epigenetic modifiers and readers of these modifications. Using an unbiased proteomic approach to find interactors of H3K36me3, a modification enriched on active chromatin, here we identify PWWP2A and HDAC2 among the top interactors. PWWP2A and its paralog PWWP2B form a stable complex with NuRD subunits MTA1/2/3:HDAC1/2:RBBP4/7, but not with MBD2/3, p66α/β, and CHD3/4. PWWP2A competes with MBD3 for binding to MTA1, thus defining a new variant NuRD complex that is mutually exclusive with the MBD2/3 containing NuRD. In mESCs, PWWP2A/B is most enriched at highly transcribed genes. Loss of PWWP2A/B leads to increases in histone acetylation predominantly at highly expressed genes, accompanied by decreases in Pol II elongation. Collectively, these findings suggest a role for PWWP2A/B in regulating transcription through the fine-tuning of histone acetylation dynamics at actively transcribed genes. Transcription regulation requires recruitment of different epigenetic regulators to the chromatin. Here the authors provide evidence that an H3K36me3 reader PWWP2A forms a variant NuRD complex and plays a role in regulating transcription and histone acetylation dynamics.
Collapse
Affiliation(s)
- Tianyi Zhang
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Guifeng Wei
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Christopher J Millard
- Leicester Institute for Structural and Chemical Biology and Department of Molecular and Cell Biology, University of Leicester, Leicester, LE1 7RH, United Kingdom
| | - Roman Fischer
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom
| | - Rebecca Konietzny
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom.,Agilent Technologies, Hewlett-Packard-Str. 8, 76337, Waldbronn, Germany
| | - Benedikt M Kessler
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom
| | - John W R Schwabe
- Leicester Institute for Structural and Chemical Biology and Department of Molecular and Cell Biology, University of Leicester, Leicester, LE1 7RH, United Kingdom
| | - Neil Brockdorff
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom.
| |
Collapse
|
52
|
Cremer T, Cremer M, Cremer C. The 4D Nucleome: Genome Compartmentalization in an Evolutionary Context. BIOCHEMISTRY (MOSCOW) 2018; 83:313-325. [PMID: 29626919 DOI: 10.1134/s000629791804003x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
4D nucleome research aims to understand the impact of nuclear organization in space and time on nuclear functions, such as gene expression patterns, chromatin replication, and the maintenance of genome integrity. In this review we describe evidence that the origin of 4D genome compartmentalization can be traced back to the prokaryotic world. In cell nuclei of animals and plants chromosomes occupy distinct territories, built up from ~1 Mb chromatin domains, which in turn are composed of smaller chromatin subdomains and also form larger chromatin domain clusters. Microscopic evidence for this higher order chromatin landscape was strengthened by chromosome conformation capture studies, in particular Hi-C. This approach demonstrated ~1 Mb sized, topologically associating domains in mammalian cell nuclei separated by boundaries. Mutations, which destroy boundaries, can result in developmental disorders and cancer. Nucleosomes appeared first as tetramers in the Archaea kingdom and later evolved to octamers built up each from two H2A, two H2B, two H3, and two H4 proteins. Notably, nucleosomes were lost during the evolution of the Dinoflagellata phylum. Dinoflagellate chromosomes remain condensed during the entire cell cycle, but their chromosome architecture differs radically from the architecture of other eukaryotes. In summary, the conservation of fundamental features of higher order chromatin arrangements throughout the evolution of metazoan animals suggests the existence of conserved, but still unknown mechanism(s) controlling this architecture. Notwithstanding this conservation, a comparison of metazoans and protists also demonstrates species-specific structural and functional features of nuclear organization.
Collapse
Affiliation(s)
- T Cremer
- Biocenter, Department of Biology II, Ludwig Maximilian University (LMU), Munich, Germany.
| | | | | |
Collapse
|
53
|
Stachecka J, Walczak A, Kociucka B, Ruszczycki B, Wilczyński G, Szczerbal I. Nuclear organization during in vitro differentiation of porcine mesenchymal stem cells (MSCs) into adipocytes. Histochem Cell Biol 2017; 149:113-126. [PMID: 29134302 DOI: 10.1007/s00418-017-1618-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2017] [Indexed: 12/19/2022]
Abstract
Differentiation of progenitor cells into adipocytes is accompanied by remarkable changes in cell morphology, cytoskeletal organization, and gene expression profile. Mature adipocytes are filled with a large lipid droplet and the nucleus tends to move to the cell periphery. It was hypothesized that the differentiation process is also associated with changes of nuclear organization. The aim of this study was to determine the number and distribution of selected components of nuclear architecture during porcine in vitro adipogenesis. The pig is an important animal model sharing many similarities to humans at the anatomical, physiological, and genetic levels and has been recognized as a good model for human obesity. Thus, understanding how cellular structures important for fundamental nuclear processes may be altered during adipocyte differentiation is of great importance. Mesenchymal stem cells (MSCs) were derived from bone marrow (BM-MSCs) and adipose tissue (AD-MSCs) and were cultured for 7 days in the adipogenic medium. A variable differentiation potential of these cell populations towards adipogenic lineage was observed, and for further study, a comparative characteristic of the nuclear organization in BM-MSCs and AD-MSCs was performed. Nuclear substructures were visualized by indirect immunofluorescence (nucleoli, nuclear speckles, PML bodies, lamins, and HP1α) or fluorescence in situ hybridization (telomeres) on fixed cells at 0, 3, 5, and 7 days of differentiation. Comprehensive characterization of these structures, in terms of their number, size, dynamics, and arrangement in three-dimensional space of the nucleus, was performed. It was found that during differentiation of porcine MSCs into adipocytes, changes of nuclear organization occurred and concerned: (1) the nuclear size and shape; (2) reduced lamin A/C expression; and (3) reorganization of chromocenters. Other elements of nuclear architecture such as nucleoli, SC-35 nuclear speckles, and telomeres showed no significant changes when compared to undifferentiated and mature fat cells. In addition, the presence of a low number of PML bodies was characteristic of the studied porcine mesenchymal stem cell adipogenesis system. It has been shown that the arrangement of selected components of nuclear architecture was very similar in MSCs derived from different sources, whereas adipocyte differentiation involves nuclear reorganization. This study adds new data on nuclear organization during adipogenesis using the pig as a model organism.
Collapse
Affiliation(s)
- Joanna Stachecka
- Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637, Poznan, Poland
| | - Agnieszka Walczak
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland
| | - Beata Kociucka
- Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637, Poznan, Poland
| | - Błażej Ruszczycki
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteura 3, 02-093, Warsaw, Poland
| | - Grzegorz Wilczyński
- Laboratory of Molecular and Systemic Neuromorphology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteura 3, 02-093, Warsaw, Poland
| | - Izabela Szczerbal
- Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637, Poznan, Poland.
| |
Collapse
|
54
|
Festuccia N, Gonzalez I, Owens N, Navarro P. Mitotic bookmarking in development and stem cells. Development 2017; 144:3633-3645. [DOI: 10.1242/dev.146522] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The changes imposed on the nucleus, chromatin and its regulators during mitosis lead to the dismantlement of most gene regulatory processes. However, an increasing number of transcriptional regulators are being identified as capable of binding their genomic targets during mitosis. These so-called ‘mitotic bookmarking factors’ encompass transcription factors and chromatin modifiers that are believed to convey gene regulatory information from mother to daughter cells. In this Primer, we review mitotic bookmarking processes in development and stem cells and discuss the interest and potential importance of this concept with regard to epigenetic regulation and cell fate transitions involving cellular proliferation.
Collapse
Affiliation(s)
- Nicola Festuccia
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Inma Gonzalez
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Nick Owens
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Pablo Navarro
- Epigenetics of Stem Cells, Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| |
Collapse
|
55
|
Hubé F, Ulveling D, Sureau A, Forveille S, Francastel C. Short intron-derived ncRNAs. Nucleic Acids Res 2017; 45:4768-4781. [PMID: 28053119 PMCID: PMC5416886 DOI: 10.1093/nar/gkw1341] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/21/2016] [Indexed: 01/02/2023] Open
Abstract
Introns represent almost half of the human genome, although they are eliminated from transcripts through RNA splicing. Yet, different classes of non-canonical miRNAs have been proposed to originate directly from intron splicing. Here, we considered the alternative splicing of introns as an interesting source of miRNAs, compatible with a developmental switch. We report computational prediction of new Short Intron-Derived ncRNAs (SID), defined as precursors of smaller ncRNAs like miRNAs and snoRNAs produced directly by splicing, and tested their dependence on each key factor in canonical or alternative miRNAs biogenesis (Drosha, DGCR8, DBR1, snRNP70, U2AF65, PRP8, Dicer, Ago2). We found that about half of predicted SID rely on debranching of the excised intron-lariat by the enzyme DBR1, as proposed for mirtrons. However, we identified new classes of SID for which miRNAs biogenesis may rely on intermingling between canonical and alternative pathways. We validated selected SID as putative miRNAs precursors and identified new endogenous miRNAs produced by non-canonical pathways, including one hosted in the first intron of SRA (Steroid Receptor RNA activator). Consistent with increased SRA intron retention during myogenic differentiation, release of SRA intron and its associated mature miRNA decreased in cells from healthy subjects but not from myotonic dystrophy patients with splicing defects.
Collapse
Affiliation(s)
- Florent Hubé
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Epigénétique et Destin Cellulaire, CNRS UMR 7216, Paris, France
| | - Damien Ulveling
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Epigénétique et Destin Cellulaire, CNRS UMR 7216, Paris, France
| | - Alain Sureau
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Epigénétique et Destin Cellulaire, CNRS UMR 7216, Paris, France
| | - Sabrina Forveille
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Epigénétique et Destin Cellulaire, CNRS UMR 7216, Paris, France
| | - Claire Francastel
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Epigénétique et Destin Cellulaire, CNRS UMR 7216, Paris, France
| |
Collapse
|
56
|
Imai R, Nozaki T, Tani T, Kaizu K, Hibino K, Ide S, Tamura S, Takahashi K, Shribak M, Maeshima K. Density imaging of heterochromatin in live cells using orientation-independent-DIC microscopy. Mol Biol Cell 2017; 28:3349-3359. [PMID: 28835378 PMCID: PMC5687035 DOI: 10.1091/mbc.e17-06-0359] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/17/2017] [Accepted: 08/18/2017] [Indexed: 11/27/2022] Open
Abstract
Using orientation-independent-DIC microscopy, we revealed that the density of total materials in heterochromatin was only 1.53-fold higher than that of euchromatin, whereas the DNA density was 7.5-fold higher. This surprisingly small difference may be due to the dominance of proteins and RNAs in both chromatins, which may help create a moderate barrier to heterochromatin. In eukaryotic cells, highly condensed inactive/silenced chromatin has long been called “heterochromatin.” However, recent research suggests that such regions are in fact not fully transcriptionally silent and that there exists only a moderate access barrier to heterochromatin. To further investigate this issue, it is critical to elucidate the physical properties of heterochromatin such as its total density in live cells. Here, using orientation-independent differential interference contrast (OI-DIC) microscopy, which is capable of mapping optical path differences, we investigated the density of the total materials in pericentric foci, a representative heterochromatin model, in live mouse NIH3T3 cells. We demonstrated that the total density of heterochromatin (208 mg/ml) was only 1.53-fold higher than that of the surrounding euchromatic regions (136 mg/ml) while the DNA density of heterochromatin was 5.5- to 7.5-fold higher. We observed similar minor differences in density in typical facultative heterochromatin, the inactive human X chromosomes. This surprisingly small difference may be due to that nonnucleosomal materials (proteins/RNAs) (∼120 mg/ml) are dominant in both chromatin regions. Monte Carlo simulation suggested that nonnucleosomal materials contribute to creating a moderate access barrier to heterochromatin, allowing minimal protein access to functional regions. Our OI-DIC imaging offers new insight into the live cellular environments.
Collapse
Affiliation(s)
- Ryosuke Imai
- Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.,Department of Genetics, School of Life Science, Sokendai (Graduate University for Advanced Studies), Mishima, Shizuoka 411-8540, Japan
| | - Tadasu Nozaki
- Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Tomomi Tani
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543
| | - Kazunari Kaizu
- Laboratory for Biochemical Simulation, RIKEN Quantitative Biology Center, Suita, Osaka 565-0874, Japan
| | - Kayo Hibino
- Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.,Department of Genetics, School of Life Science, Sokendai (Graduate University for Advanced Studies), Mishima, Shizuoka 411-8540, Japan
| | - Satoru Ide
- Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.,Department of Genetics, School of Life Science, Sokendai (Graduate University for Advanced Studies), Mishima, Shizuoka 411-8540, Japan
| | - Sachiko Tamura
- Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Koichi Takahashi
- Laboratory for Biochemical Simulation, RIKEN Quantitative Biology Center, Suita, Osaka 565-0874, Japan
| | - Michael Shribak
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543
| | - Kazuhiro Maeshima
- Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan .,Department of Genetics, School of Life Science, Sokendai (Graduate University for Advanced Studies), Mishima, Shizuoka 411-8540, Japan
| |
Collapse
|
57
|
Ludwig AK, Zhang P, Hastert FD, Meyer S, Rausch C, Herce HD, Müller U, Lehmkuhl A, Hellmann I, Trummer C, Storm C, Leonhardt H, Cardoso MC. Binding of MBD proteins to DNA blocks Tet1 function thereby modulating transcriptional noise. Nucleic Acids Res 2017; 45:2438-2457. [PMID: 27923996 PMCID: PMC5389475 DOI: 10.1093/nar/gkw1197] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/20/2016] [Indexed: 12/18/2022] Open
Abstract
Aberrant DNA methylation is a hallmark of various human disorders, indicating that the spatial and temporal regulation of methylation readers and modifiers is imperative for development and differentiation. In particular, the cross-regulation between 5-methylcytosine binders (MBD) and modifiers (Tet) has not been investigated. Here, we show that binding of Mecp2 and Mbd2 to DNA protects 5-methylcytosine from Tet1-mediated oxidation. The mechanism is not based on competition for 5-methylcytosine binding but on Mecp2 and Mbd2 directly restricting Tet1 access to DNA. We demonstrate that the efficiency of this process depends on the number of bound MBDs per DNA molecule. Accordingly, we find 5-hydroxymethylcytosine enriched at heterochromatin of Mecp2-deficient neurons of a mouse model for Rett syndrome and Tet1-induced reexpression of silenced major satellite repeats. These data unveil fundamental regulatory mechanisms of Tet enzymes and their potential pathophysiological role in Rett syndrome. Importantly, it suggests that Mecp2 and Mbd2 have an essential physiological role as guardians of the epigenome.
Collapse
Affiliation(s)
- Anne K Ludwig
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Peng Zhang
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Florian D Hastert
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Stephanie Meyer
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Cathia Rausch
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Henry D Herce
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Udo Müller
- Human Biology and BioImaging, Department of Biology II, LMU Munich, 82152 Martinsried, Germany
| | - Anne Lehmkuhl
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Ines Hellmann
- Anthropology and Human Genomics, Department Biology II, LMU Munich, 82152 Martinsried, Germany
| | - Carina Trummer
- Human Biology and BioImaging, Department of Biology II, LMU Munich, 82152 Martinsried, Germany
| | - Christian Storm
- Chemical Plant Ecology, Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Heinrich Leonhardt
- Human Biology and BioImaging, Department of Biology II, LMU Munich, 82152 Martinsried, Germany
| | - M Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| |
Collapse
|
58
|
Herce HD, Schumacher D, Schneider AFL, Ludwig AK, Mann FA, Fillies M, Kasper MA, Reinke S, Krause E, Leonhardt H, Cardoso MC, Hackenberger CPR. Cell-permeable nanobodies for targeted immunolabelling and antigen manipulation in living cells. Nat Chem 2017; 9:762-771. [DOI: 10.1038/nchem.2811] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 05/24/2017] [Indexed: 12/19/2022]
|
59
|
Zhang P, Rausch C, Hastert FD, Boneva B, Filatova A, Patil SJ, Nuber UA, Gao Y, Zhao X, Cardoso MC. Methyl-CpG binding domain protein 1 regulates localization and activity of Tet1 in a CXXC3 domain-dependent manner. Nucleic Acids Res 2017; 45:7118-7136. [PMID: 28449087 PMCID: PMC5499542 DOI: 10.1093/nar/gkx281] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 03/30/2017] [Accepted: 04/06/2017] [Indexed: 12/20/2022] Open
Abstract
Cytosine modifications diversify and structure the genome thereby controlling proper development and differentiation. Here, we focus on the interplay of the 5-methylcytosine reader Mbd1 and modifier Tet1 by analyzing their dynamic subcellular localization and the formation of the Tet oxidation product 5-hydroxymethylcytosine in mammalian cells. Our results demonstrate that Mbd1 enhances Tet1-mediated 5-methylcytosine oxidation. We show that this is due to enhancing the localization of Tet1, but not of Tet2 and Tet3 at heterochromatic DNA. We find that the recruitment of Tet1 and concomitantly its catalytic activity eventually leads to the displacement of Mbd1 from methylated DNA. Finally, we demonstrate that increased Tet1 heterochromatin localization and 5-methylcytosine oxidation are dependent on the CXXC3 domain of Mbd1, which recognizes unmethylated CpG dinucleotides. The Mbd1 CXXC3 domain deletion isoform, which retains only binding to methylated CpGs, on the other hand, blocks Tet1-mediated 5-methylcytosine to 5-hydroxymethylcytosine conversion, indicating opposite biological effects of Mbd1 isoforms. Our study provides new insights on how cytosine modifications, their modifiers and readers cross-regulate themselves.
Collapse
Affiliation(s)
- Peng Zhang
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Cathia Rausch
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Florian D. Hastert
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Boyana Boneva
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Alina Filatova
- Stem Cell and Developmental Biology, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Sujit J. Patil
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Ulrike A. Nuber
- Stem Cell and Developmental Biology, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Yu Gao
- Waisman Center & Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Xinyu Zhao
- Waisman Center & Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - M. Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| |
Collapse
|
60
|
Zhang P, Ludwig AK, Hastert FD, Rausch C, Lehmkuhl A, Hellmann I, Smets M, Leonhardt H, Cardoso MC. L1 retrotransposition is activated by Ten-eleven-translocation protein 1 and repressed by methyl-CpG binding proteins. Nucleus 2017; 8:548-562. [PMID: 28524723 PMCID: PMC5703239 DOI: 10.1080/19491034.2017.1330238] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
One of the major functions of DNA methylation is the repression of transposable elements, such as the long-interspersed nuclear element 1 (L1). The underlying mechanism(s), however, are unclear. Here, we addressed how retrotransposon activation and mobilization are regulated by methyl-cytosine modifying ten-eleven-translocation (Tet) proteins and how this is modulated by methyl-CpG binding domain (MBD) proteins. We show that Tet1 activates both, endogenous and engineered L1 retrotransposons. Furthermore, we found that Mecp2 and Mbd2 repress Tet1-mediated activation of L1 by preventing 5hmC formation at the L1 promoter. Finally, we demonstrate that the methyl-CpG binding domain, as well as the adjacent non-sequence specific DNA binding domain of Mecp2 are each sufficient to mediate repression of Tet1-induced L1 mobilization. Our study reveals a mechanism how L1 elements get activated in the absence of Mecp2 and suggests that Tet1 may contribute to Mecp2/Mbd2-deficiency phenotypes, such as the Rett syndrome. We propose that the balance between methylation "reader" and "eraser/writer" controls L1 retrotransposition.
Collapse
Affiliation(s)
- Peng Zhang
- a Department of Biology , Technical University Darmstadt , Darmstadt , Germany
| | - Anne K Ludwig
- a Department of Biology , Technical University Darmstadt , Darmstadt , Germany
| | - Florian D Hastert
- a Department of Biology , Technical University Darmstadt , Darmstadt , Germany
| | - Cathia Rausch
- a Department of Biology , Technical University Darmstadt , Darmstadt , Germany
| | - Anne Lehmkuhl
- a Department of Biology , Technical University Darmstadt , Darmstadt , Germany
| | - Ines Hellmann
- b Anthropology and Human Genomics, Department Biology II , LMU Munich , Germany
| | - Martha Smets
- c Human Biology and BioImaging, Department of Biology II , LMU Munich , Germany
| | - Heinrich Leonhardt
- c Human Biology and BioImaging, Department of Biology II , LMU Munich , Germany
| | - M Cristina Cardoso
- a Department of Biology , Technical University Darmstadt , Darmstadt , Germany
| |
Collapse
|
61
|
The Crucial Role of DNA Methylation and MeCP2 in Neuronal Function. Genes (Basel) 2017; 8:genes8050141. [PMID: 28505093 PMCID: PMC5448015 DOI: 10.3390/genes8050141] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/25/2017] [Accepted: 05/05/2017] [Indexed: 12/16/2022] Open
Abstract
A neuron is unique in its ability to dynamically modify its transcriptional output in response to synaptic activity while maintaining a core gene expression program that preserves cellular identity throughout a lifetime that is longer than almost every other cell type in the body. A contributing factor to the immense adaptability of a neuron is its unique epigenetic landscape that elicits locus-specific alterations in chromatin architecture, which in turn influences gene expression. One such epigenetic modification that is sensitive to changes in synaptic activity, as well as essential for maintaining cellular identity, is DNA methylation. The focus of this article is on the importance of DNA methylation in neuronal function, summarizing recent studies on critical players in the establishment of (the “writing”), the modification or erasure of (the “editing”), and the mediation of (the “reading”) DNA methylation in neurodevelopment and neuroplasticity. One “reader” of DNA methylation in particular, methyl-CpG-binding protein 2 (MeCP2), is highlighted, given its undisputed importance in neuronal function.
Collapse
|
62
|
Salsman J, Rapkin LM, Margam NN, Duncan R, Bazett-Jones DP, Dellaire G. Myogenic differentiation triggers PML nuclear body loss and DAXX relocalization to chromocentres. Cell Death Dis 2017; 8:e2724. [PMID: 28358373 PMCID: PMC5386546 DOI: 10.1038/cddis.2017.151] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/05/2017] [Accepted: 03/07/2017] [Indexed: 12/12/2022]
Abstract
The promyelocytic leukemia protein (PML) is expressed in most normal human tissues and forms nuclear bodies (NBs) that have roles in gene regulation and cellular processes such as DNA repair, cell cycle control, and cell fate decisions. Using murine C2C12 myoblasts, we demonstrate that activation of skeletal muscle differentiation results in loss of PML and PML NBs prior to myotube fusion. Myotube formation was associated with marked chromatin reorganization and the relocalization of DAXX from PML NBs to chromocentres. MyoD expression was sufficient to cause PML NB loss, and silencing of PML induced DAXX relocalization. Fusion of C2C12 cells using the reptilian reovirus p14 fusogenic protein failed to disrupt PML NBs yet still promoted DAXX redistribution and loss; whereas ectopic expression of PML in differentiated cells only partially restored PML NB formation and DAXX localization at NBs. Finally, we determined that the C-terminal SUMO-interacting motif of DAXX is required for its colocalization with ATRX in heterochromatin domains during myotube formation. These data support a model in which activation of myogenic differentiation results in PML NB loss, chromatin reorganization and DAXX relocalization, and provides a paradigm for understanding the consequence of PML loss in other cellular contexts, such as during cancer development and progression.
Collapse
Affiliation(s)
- Jayme Salsman
- Department of Pathology, Dalhousie University, Halifax, NS, Canada, B3H 4R2
| | - Lindsy M Rapkin
- Genetics & Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 1X8
| | - Nandini N Margam
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS, Canada, B3H 4R2
| | - Roy Duncan
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS, Canada, B3H 4R2
| | - David P Bazett-Jones
- Genetics & Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 1X8
| | - Graham Dellaire
- Department of Pathology, Dalhousie University, Halifax, NS, Canada, B3H 4R2.,Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, Canada, B3H 4R2
| |
Collapse
|
63
|
DNA methylation is dispensable for changes in global chromatin architecture but required for chromocentre formation in early stem cell differentiation. Chromosoma 2017; 126:605-614. [PMID: 28084535 DOI: 10.1007/s00412-017-0625-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 12/21/2016] [Accepted: 01/02/2017] [Indexed: 01/05/2023]
Abstract
Epiblast stem cells (EpiSCs), which are pluripotent cells isolated from early post-implantation mouse embryos (E5.5), show both similarities and differences compared to mouse embryonic stem cells (mESCs), isolated earlier from the inner cell mass (ICM) of the E3.5 embryo. Previously, we have observed that while chromatin is very dispersed in E3.5 ICM, compact chromatin domains and chromocentres appear in E5.5 epiblasts after embryo implantation. Given that the observed chromatin re-organization in E5.5 epiblasts coincides with an increase in DNA methylation, in this study, we aimed to examine the role of DNA methylation in chromatin re-organization during the in vitro conversion of ESCs to EpiSCs. The requirement for DNA methylation was determined by converting both wild-type and DNA methylation-deficient ESCs to EpiSCs, followed by structural analysis with electron spectroscopic imaging (ESI). We show that the chromatin re-organization which occurs in vivo can be re-capitulated in vitro during the ESC to EpiSC conversion. Indeed, after 7 days in EpiSC media, compact chromatin domains begin to appear throughout the nuclear volume, creating a chromatin organization similar to E5 epiblasts and embryo-derived EpiSCs. Our data demonstrate that DNA methylation is dispensable for this global chromatin re-organization but required for the compaction of pericentromeric chromatin into chromocentres.
Collapse
|
64
|
Chen KW, Chang YJ, Yeh CM, Lian YL, Chan MWY, Kao CF, Chen L. SH2B1 modulates chromatin state and MyoD occupancy to enhance expressions of myogenic genes. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1860:270-281. [PMID: 28039048 DOI: 10.1016/j.bbagrm.2016.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 11/29/2016] [Accepted: 12/23/2016] [Indexed: 10/20/2022]
Abstract
As mesoderm-derived cell lineage commits to myogenesis, a spectrum of signaling molecules, including insulin growth factor (IGF), activate signaling pathways and ultimately instruct chromatin remodeling and the transcription of myogenic genes. MyoD is a key transcription factor during myogenesis. In this study, we have identified and characterized a novel myogenic regulator, SH2B1. Knocking down SH2B1 delays global chromatin condensation and decreases the formation of myotubes. SH2B1 interacts with histone H1 and is required for the removal of histone H1 from active transcription sites, allowing for the expressions of myogenic genes, IGF2 and MYOG. Chromatin immunoprecipitation assays suggest the requirement of SH2B1 for the induction of histone H3 lysine 4 trimethylation as well as the reduction of histone H3 lysine 9 trimethylation at the promoters and/or enhancers of IGF2 and MYOG genes during myogenesis. Furthermore, SH2B1 is required for the transcriptional activity of MyoD and MyoD occupancy at the enhancer/promoter regions of IGF2 and MYOG during myogenesis. Together, this study demonstrates that SH2B1 fine-tunes global-local chromatin states, expressions of myogenic genes and ultimately promotes myogenesis.
Collapse
Affiliation(s)
- Kuan-Wei Chen
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, Taiwan, R.O.C
| | - Yu-Jung Chang
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, Taiwan, R.O.C
| | - Chia-Ming Yeh
- Department of Life Science, National Chung Cheng University, Chia-yi, Taiwan, R.O.C
| | - Yen-Ling Lian
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, Taiwan, R.O.C
| | - Michael W Y Chan
- Department of Life Science, National Chung Cheng University, Chia-yi, Taiwan, R.O.C
| | - Cheng-Fu Kao
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, R.O.C
| | - Linyi Chen
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, Taiwan, R.O.C.; Department of Medical Science, National Tsing Hua University, Hsinchu, Taiwan, R.O.C..
| |
Collapse
|
65
|
Leonard H, Cobb S, Downs J. Clinical and biological progress over 50 years in Rett syndrome. Nat Rev Neurol 2016; 13:37-51. [PMID: 27934853 DOI: 10.1038/nrneurol.2016.186] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the 50 years since Andreas Rett first described the syndrome that came to bear his name, and is now known to be caused by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene, a compelling blend of astute clinical observations and clinical and laboratory research has substantially enhanced our understanding of this rare disorder. Here, we document the contributions of the early pioneers in Rett syndrome (RTT) research, and describe the evolution of knowledge in terms of diagnostic criteria, clinical variation, and the interplay with other Rett-related disorders. We provide a synthesis of what is known about the neurobiology of MeCP2, considering the lessons learned from both cell and animal models, and how they might inform future clinical trials. With a focus on the core criteria, we examine the relationships between genotype and clinical severity. We review current knowledge about the many comorbidities that occur in RTT, and how genotype may modify their presentation. We also acknowledge the important drivers that are accelerating this research programme, including the roles of research infrastructure, international collaboration and advocacy groups. Finally, we highlight the major milestones since 1966, and what they mean for the day-to-day lives of individuals with RTT and their families.
Collapse
Affiliation(s)
- Helen Leonard
- Telethon Kids Institute, 100 Roberts Road, Subiaco, Perth, Western Australia 6008, Australia
| | - Stuart Cobb
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Jenny Downs
- Telethon Kids Institute, 100 Roberts Road, Subiaco, Perth, Western Australia 6008, Australia
| |
Collapse
|
66
|
Maslova A, Zlotina A, Kosyakova N, Sidorova M, Krasikova A. Three-dimensional architecture of tandem repeats in chicken interphase nucleus. Chromosome Res 2016; 23:625-39. [PMID: 26316311 DOI: 10.1007/s10577-015-9485-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Tandem repeats belong to a class of genomic repetitive elements that form arrays of head-to-tail monomers. Due to technical difficulties in sequencing and assembly of large tandem repeat arrays, it remains largely unknown by which mechanisms tandem-repeat-containing regions aid in maintenance of ordered radial genome organization during interphase. Here we analyzed spatial distribution of several types of tandem repeats in interphase nuclei of chicken MDCC-MSB1 cells and somatic tissues relative to heterochromatin compartments and nuclear center. We showed that telomere and subtelomere repeats generally localize at the nuclear or chromocenters periphery. A tandem repeat known as CNM, typical for centromere regions of gene-dense microchromosomes, forms interchromosome clusters and occupies DAPI-positive chromocenters that appear predominantly within the nuclear interior. In contrast, centromere-specific tandem repeats of the majority of gene-poor macrochromosomes are embedded into the peripheral layer of heterochromatin. Chicken chromocenters rarely comprise centromere sequences of both macro- and microchromosomes, whose territories localize in different radial nuclear zones. Possible mechanisms of observed tandem repeats positioning and its implication in highly ordered arrangement of chromosome territories in chicken interphase nucleus are discussed.
Collapse
Affiliation(s)
- Antonina Maslova
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - Anna Zlotina
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - Nadezhda Kosyakova
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Marina Sidorova
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - Alla Krasikova
- Saint Petersburg State University, Saint Petersburg, 198504, Russia.
| |
Collapse
|
67
|
Li R, Dong Q, Yuan X, Zeng X, Gao Y, Chiao C, Li H, Zhao X, Keles S, Wang Z, Chang Q. Misregulation of Alternative Splicing in a Mouse Model of Rett Syndrome. PLoS Genet 2016; 12:e1006129. [PMID: 27352031 PMCID: PMC4924826 DOI: 10.1371/journal.pgen.1006129] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 05/25/2016] [Indexed: 12/13/2022] Open
Abstract
Mutations in the human MECP2 gene cause Rett syndrome (RTT), a severe neurodevelopmental disorder that predominantly affects girls. Despite decades of work, the molecular function of MeCP2 is not fully understood. Here we report a systematic identification of MeCP2-interacting proteins in the mouse brain. In addition to transcription regulators, we found that MeCP2 physically interacts with several modulators of RNA splicing, including LEDGF and DHX9. These interactions are disrupted by RTT causing mutations, suggesting that they may play a role in RTT pathogenesis. Consistent with the idea, deep RNA sequencing revealed misregulation of hundreds of splicing events in the cortex of Mecp2 knockout mice. To reveal the functional consequence of altered RNA splicing due to the loss of MeCP2, we focused on the regulation of the splicing of the flip/flop exon of Gria2 and other AMPAR genes. We found a significant splicing shift in the flip/flop exon toward the flop inclusion, leading to a faster decay in the AMPAR gated current and altered synaptic transmission. In summary, our study identified direct physical interaction between MeCP2 and splicing factors, a novel MeCP2 target gene, and established functional connection between a specific RNA splicing change and synaptic phenotypes in RTT mice. These results not only help our understanding of the molecular function of MeCP2, but also reveal potential drug targets for future therapies. Rett syndrome (RTT) is a debilitating neurodevelopmental disorder with no cure or effective treatment. To fully understand the disease mechanism and develop therapies, it is necessary to study all aspects of the molecular function of methyl-CpG binding protein 2 (MeCP2), mutations in which have been identified as the genetic cause of RTT. Over the years, MeCP2 has been shown to maintain DNA methylation, regulate transcription and chromatin structure, control microRNA processing, and modulate RNA splicing. Among these known functions, the role of MeCP2 in modulating RNA splicing is less well understood. We took several unbiased approaches to investigate the how MeCP2 may regulate splicing, what splicing changes are caused by the loss of MeCP2, and what functional consequences are caused by altered splicing. We discovered that MeCP2 interacts with splicing factors to regulated the splicing of glutamate receptor genes, which mediate the vast majority of excitatory synaptic transmission in the brain; and linked the altered splicing of glutamate receptor genes to specific synaptic changes in a RTT mouse model. Our findings not only advance the understanding of RTT disease mechanism, but also reveal a potential drug target for future development of therapies.
Collapse
Affiliation(s)
- Ronghui Li
- CMB Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Qiping Dong
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Xinni Yuan
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Xin Zeng
- Department of Statistics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Yu Gao
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Cassandra Chiao
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Hongda Li
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Genetics Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Sunduz Keles
- Department of Statistics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Zefeng Wang
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Chinese Academy of Sciences (CAS) Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai, China
| | - Qiang Chang
- CMB Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Genetics Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Departments of Medical Genetics and Neurology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
| |
Collapse
|
68
|
Ludwig AK, Zhang P, Cardoso MC. Modifiers and Readers of DNA Modifications and Their Impact on Genome Structure, Expression, and Stability in Disease. Front Genet 2016; 7:115. [PMID: 27446199 PMCID: PMC4914596 DOI: 10.3389/fgene.2016.00115] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/06/2016] [Indexed: 12/16/2022] Open
Abstract
Cytosine base modifications in mammals underwent a recent expansion with the addition of several naturally occurring further modifications of methylcytosine in the last years. This expansion was accompanied by the identification of the respective enzymes and proteins reading and translating the different modifications into chromatin higher order organization as well as genome activity and stability, leading to the hypothesis of a cytosine code. Here, we summarize the current state-of-the-art on DNA modifications, the enzyme families setting the cytosine modifications and the protein families reading and translating the different modifications with emphasis on the mouse protein homologs. Throughout this review, we focus on functional and mechanistic studies performed on mammalian cells, corresponding mouse models and associated human diseases.
Collapse
Affiliation(s)
- Anne K Ludwig
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Darmstadt Germany
| | - Peng Zhang
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Darmstadt Germany
| | - M C Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Darmstadt Germany
| |
Collapse
|
69
|
Della Ragione F, Vacca M, Fioriniello S, Pepe G, D'Esposito M. MECP2, a multi-talented modulator of chromatin architecture. Brief Funct Genomics 2016; 15:420-431. [PMID: 27296483 DOI: 10.1093/bfgp/elw023] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
It has been a long trip from 1992, the year of the discovery of MECP2, to the present day. What is surprising is that some of the pivotal roles of MeCP2 were already postulated at that time, such as repression of inappropriate expression from repetitive elements and the regulation of pericentric heterochromatin condensation. However, MeCP2 performs many more functions. MeCP2 is a reader of epigenetic information contained in methylated (and hydroxymethylated) DNA, moving from the 'classical' CpG doublet to the more complex view addressed by the non-CpG methylation, which is a feature of the postnatal brain. MECP2 is a transcriptional repressor, although when it forms complexes with the appropriate molecules, it can become a transcriptional activator. For all of these aspects, Rett syndrome, which is caused by MECP2 mutations, is considered a paradigmatic example of a 'chromatin disorder'. Even if the hunt for bona-fide MECP2 target genes is far from concluded today, the role of MeCP2 in the maintenance of chromatin architecture appears to be clearly established. Taking a cue from the non-scientific literature, we can firmly attest that MeCP2 is a player with 'a great future behind it'*.*V. Gassmann 'Un grande avvenire dietro le spalle'. TEA Eds.
Collapse
|
70
|
Becker A, Zhang P, Allmann L, Meilinger D, Bertulat B, Eck D, Hofstaetter M, Bartolomei G, Hottiger MO, Schreiber V, Leonhardt H, Cardoso MC. Poly(ADP-ribosyl)ation of Methyl CpG Binding Domain Protein 2 Regulates Chromatin Structure. J Biol Chem 2016; 291:4873-81. [PMID: 26772194 PMCID: PMC4777825 DOI: 10.1074/jbc.m115.698357] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Indexed: 11/06/2022] Open
Abstract
The epigenetic information encoded in the genomic DNA methylation pattern is translated by methylcytosine binding proteins like MeCP2 into chromatin topology and structure and gene activity states. We have shown previously that the MeCP2 level increases during differentiation and that it causes large-scale chromatin reorganization, which is disturbed by MeCP2 Rett syndrome mutations. Phosphorylation and other posttranslational modifications of MeCP2 have been described recently to modulate its function. Here we show poly(ADP-ribosyl)ation of endogenous MeCP2 in mouse brain tissue. Consequently, we found that MeCP2 induced aggregation of pericentric heterochromatin and that its chromatin accumulation was enhanced in poly(ADP-ribose) polymerase (PARP) 1(-/-) compared with wild-type cells. We mapped the poly(ADP-ribosyl)ation domains and engineered MeCP2 mutation constructs to further analyze potential effects on DNA binding affinity and large-scale chromatin remodeling. Single or double deletion of the poly(ADP-ribosyl)ated regions and PARP inhibition increased the heterochromatin clustering ability of MeCP2. Increased chromatin clustering may reflect increased binding affinity. In agreement with this hypothesis, we found that PARP-1 deficiency significantly increased the chromatin binding affinity of MeCP2 in vivo. These data provide novel mechanistic insights into the regulation of MeCP2-mediated, higher-order chromatin architecture and suggest therapeutic opportunities to manipulate MeCP2 function.
Collapse
Affiliation(s)
- Annette Becker
- From the Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Peng Zhang
- From the Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Lena Allmann
- From the Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Daniela Meilinger
- the Center for Integrated Protein Science at the Department of Biology, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany
| | - Bianca Bertulat
- From the Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Daniel Eck
- From the Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Maria Hofstaetter
- the Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Giody Bartolomei
- the Department of Molecular Mechanisms of Disease, University of Zurich, 8057 Zurich, Switzerland, and
| | - Michael O Hottiger
- the Department of Molecular Mechanisms of Disease, University of Zurich, 8057 Zurich, Switzerland, and
| | - Valérie Schreiber
- UMR7242 Biotechnology and Cell Signaling, Laboratory of Excellence Medalis, Strasbourg University, CNRS, Ecole Superieure de Biotechnologie de Strasbourg, BP10413, 67412 Illkirch Cedex, France
| | - Heinrich Leonhardt
- the Center for Integrated Protein Science at the Department of Biology, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany
| | - M Cristina Cardoso
- From the Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany,
| |
Collapse
|
71
|
Rapkin LM, Ahmed K, Dulev S, Li R, Kimura H, Ishov AM, Bazett-Jones DP. The histone chaperone DAXX maintains the structural organization of heterochromatin domains. Epigenetics Chromatin 2015; 8:44. [PMID: 26500702 PMCID: PMC4617904 DOI: 10.1186/s13072-015-0036-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 10/07/2015] [Indexed: 12/20/2022] Open
Abstract
Background The death domain-associated protein (DAXX) collaborates with accessory proteins to deposit the histone variant H3.3 into mouse telomeric and pericentromeric repeat DNA. Pericentromeric repeats are the main genetic contributor to spatially discrete, compact, constitutive heterochromatic structures called chromocentres. Chromocentres are enriched in the H3K9me3 histone modification and serve as integral, functionally important components of nuclear organization. To date, the role of DAXX as an H3.3-specific histone chaperone has been investigated primarily using biochemical approaches which provide genome-wide views on cell populations and information on changes in local chromatin structures. However, the global chromatin and subnuclear reorganization events that coincide with these changes remain to be investigated. Results Using electron spectroscopic imagine (ESI), a specialized form of energy-filtered transmission electron microscopy that allows us to visualize chromatin domains in situ with high contrast and spatial resolution, we show that in the absence of DAXX, H3K9me3-enriched domains are structurally altered and become uncoupled from major satellite DNA. In addition, the structural integrity of nucleoli and the organization of ribosomal DNA (rDNA) are disrupted. Moreover, the absence of DAXX leads to chromatin that is more sensitive, on a global level, to micrococcal nuclease digestion. Conclusions We identify a novel role of DAXX as a major regulator of subnuclear organization through the maintenance of the global heterochromatin structural landscape. As well, we show, for the first time, that the loss of a histone chaperone can have severe consequences for global nuclear organization. Electronic supplementary material The online version of this article (doi:10.1186/s13072-015-0036-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Lindsy M Rapkin
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4 Canada ; Department of Biochemistry, The University of Toronto, Toronto, ON M5S 1A8 Canada
| | - Kashif Ahmed
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4 Canada
| | - Stanimir Dulev
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4 Canada
| | - Ren Li
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4 Canada
| | - Hiroshi Kimura
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-Ku, Yokohama 226-8501 Japan
| | - Alexander M Ishov
- Department of Anatomy and Cell Biology, University of Florida College of Medicine, and University of Florida Cancer Center, Gainesville, FL 32610 USA
| | - David P Bazett-Jones
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4 Canada ; Department of Biochemistry, The University of Toronto, Toronto, ON M5S 1A8 Canada
| |
Collapse
|
72
|
Jost KL, Bertulat B, Rapp A, Brero A, Hardt T, Domaing P, Gösele C, Schulz H, Hübner N, Cardoso MC. Gene repositioning within the cell nucleus is not random and is determined by its genomic neighborhood. Epigenetics Chromatin 2015; 8:36. [PMID: 26388944 PMCID: PMC4574441 DOI: 10.1186/s13072-015-0025-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 09/01/2015] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Heterochromatin has been reported to be a major silencing compartment during development and differentiation. Prominent heterochromatin compartments are located at the nuclear periphery and inside the nucleus (e.g., pericentric heterochromatin). Whether the position of a gene in relation to some or all heterochromatin compartments matters remains a matter of debate, which we have addressed in this study. Answering this question demanded solving the technical challenges of 3D measurements and the large-scale morphological changes accompanying cellular differentiation. RESULTS Here, we investigated the proximity effects of the nuclear periphery and pericentric heterochromatin on gene expression and additionally considered the effect of neighboring genomic features on a gene's nuclear position. Using a well-established myogenic in vitro differentiation system and a differentiation-independent heterochromatin remodeling system dependent on ectopic MeCP2 expression, we first identified genes with statistically significant expression changes by transcriptional profiling. We identified nuclear gene positions by 3D fluorescence in situ hybridization followed by 3D distance measurements toward constitutive and facultative heterochromatin domains. Single-cell-based normalization enabled us to acquire morphologically unbiased data and we finally correlated changes in gene positioning to changes in transcriptional profiles. We found no significant correlation of gene silencing and proximity to constitutive heterochromatin and a rather unexpected inverse correlation of gene activity and position relative to facultative heterochromatin at the nuclear periphery. CONCLUSION In summary, our data question the hypothesis of heterochromatin as a general silencing compartment. Nonetheless, compared to a simulated random distribution, we found that genes are not randomly located within the nucleus. An analysis of neighboring genomic context revealed that gene location within the nucleus is rather dependent on CpG islands, GC content, gene density, and short and long interspersed nuclear elements, collectively known as RIDGE (regions of increased gene expression) properties. Although genes do not move away/to the heterochromatin upon up-/down-regulation, genomic regions with RIDGE properties are generally excluded from peripheral heterochromatin. Hence, we suggest that individual gene activity does not influence gene positioning, but rather chromosomal context matters for sub-nuclear location.
Collapse
Affiliation(s)
- K Laurence Jost
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Bianca Bertulat
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Alexander Rapp
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Alessandro Brero
- Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Tanja Hardt
- Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Petra Domaing
- Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Claudia Gösele
- Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Herbert Schulz
- Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Norbert Hübner
- Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - M Cristina Cardoso
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| |
Collapse
|
73
|
Meng H, Harrison DJ, Meehan RR. MBD4 interacts with and recruits USP7 to heterochromatic foci. J Cell Biochem 2015; 116:476-85. [PMID: 25358258 PMCID: PMC4964934 DOI: 10.1002/jcb.25001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/23/2014] [Indexed: 12/19/2022]
Abstract
MBD4 is the only methyl‐CpG binding protein that possesses a C‐terminal glycosylase domain. It has been associated with a number of nuclear pathways including DNA repair, DNA damage response, the initiation of apoptosis, transcriptional repression, and DNA demethylation. However, the precise contribution of MBD4 to these processes in development and relevant diseases remains elusive. We identified UHRF1 and USP7 as two new interaction partners for MBD4. Both UHRF1, a E3 ubiquitin ligase, and USP7, a de‐ubiquinating enzyme, regulate the stability of the DNA maintenance methyltransferase, Dnmt1. The ability of MBD4 to directly interact with and recruit USP7 to chromocenters implicates it as an additional factor that can potentially regulate Dnmt1 activity during cell proliferation. J. Cell. Biochem. 116: 476–485, 2015. © 2014 The Authors. Journal of Cellular Biochemistry published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Huan Meng
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK; Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | | | | |
Collapse
|
74
|
Du Q, Luu PL, Stirzaker C, Clark SJ. Methyl-CpG-binding domain proteins: readers of the epigenome. Epigenomics 2015; 7:1051-73. [DOI: 10.2217/epi.15.39] [Citation(s) in RCA: 265] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
How DNA methylation is interpreted and influences genome regulation remains largely unknown. Proteins of the methyl-CpG-binding domain (MBD) family are primary candidates for the readout of DNA methylation as they recruit chromatin remodelers, histone deacetylases and methylases to methylated DNA associated with gene repression. MBD protein binding requires both functional MBD domains and methyl-CpGs; however, some MBD proteins also bind unmethylated DNA and active regulatory regions via alternative regulatory domains or interaction with the nucleosome remodeling deacetylase (NuRD/Mi-2) complex members. Mutations within MBD domains occur in many diseases, including neurological disorders and cancers, leading to loss of MBD binding specificity to methylated sites and gene deregulation. Here, we summarize the current state of knowledge about MBD proteins and their role as readers of the epigenome.
Collapse
Affiliation(s)
- Qian Du
- Epigenetics Research Laboratory, Genomics & Epigenetics Division, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
| | - Phuc-Loi Luu
- Epigenetics Research Laboratory, Genomics & Epigenetics Division, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
| | - Clare Stirzaker
- Epigenetics Research Laboratory, Genomics & Epigenetics Division, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
- St Vincent's Clinical School, University of NSW, Darlinghurst, NSW 2010, Australia
| | - Susan J Clark
- Epigenetics Research Laboratory, Genomics & Epigenetics Division, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
- St Vincent's Clinical School, University of NSW, Darlinghurst, NSW 2010, Australia
| |
Collapse
|
75
|
Kameoka Y, Kitazawa R, Ariasu K, Tachibana R, Mizuno Y, Haraguchi R, Kitazawa S. Reactivation of CDX2 in Gastric Cancer as Mark for Gene Silencing Memory. Acta Histochem Cytochem 2015; 48:115-24. [PMID: 26379313 PMCID: PMC4564377 DOI: 10.1267/ahc.15014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 06/30/2015] [Indexed: 01/05/2023] Open
Abstract
To explore the epigenetic mechanism that reactivates CDX2 (a homeobox transcription factor that serves as a tumor-suppressor gene) in intestinal-type gastric cancer during cancer progression, we examined the methylation status of the CDX2 gene promoter and the expression pattern of methyl-CpG binding protein-2 (MeCP2). From archives of the pathology records of surgically excised advanced stomach cancer cases in the Department of Molecular Pathology, Ehime University in a past decate (n=265), 10 cases of intestinal-type tubular adenocarcinoma, well-differentiated type (wel) with minor poorly-differentiated adenocarcinoma (por) components were selected. The expression pattern of CDX2, MUC2 and MeCP2 in these 10 cases was analyzed by immunohistochemistry. The cancerous and non-cancerous areas were selectively obtained by microdissection, and the methylation status of the CDX2 promoter of each area was assessed by methylation-specific polymerase chain reaction (MSP). In all 10 cases, CDX2 expression was clearly observed in the nucleus of the non-cancerous background of the intestinal metaplasic area, where the unmethylation pattern of the CDX2 gene promoter prevailed with reduced MeCP2 expression. In this metaplastic area, CDX2 expression was co-localized with its target gene, MUC2. CDX2 expression then disappeared from the deep invasive wel area. Reflecting the reduced CDX2 expression, microdissected samples from all the wel areas showed hypermethylation of the CDX2 gene promoter by MSP, with prominent MeCP2 expression. Interestingly, while hypermethylation of the CDX2 gene promoter was maintained in the por area in 8 of the 10 cases, CDX2 expression was restored in por areas where MeCP2 expression was markedly and selectively reduced. The other two cases, however, showed a constant MeCP2 expression level comparable to the surrounding deep invasive wel area with negative CDX2 expression. Therefore, gene silencing by hypermethylation may be overcome by the reduction of methyl-CpG binding proteins, resulting in apparent but non-functional reactivation of CDX2 as a mere molecular mark for gene silencing memory.
Collapse
Affiliation(s)
- Yuri Kameoka
- Department of Molecular Pathology, Ehime University Graduate School of Medicine
| | - Riko Kitazawa
- Department of Molecular Pathology, Ehime University Graduate School of Medicine
- Department of Diagnostic Pathology, Ehime University Hospital
| | - Kanazu Ariasu
- Department of Molecular Pathology, Ehime University Graduate School of Medicine
| | - Ryosuke Tachibana
- Department of Molecular Pathology, Ehime University Graduate School of Medicine
| | - Yosuke Mizuno
- Department of Diagnostic Pathology, Ehime University Hospital
| | - Ryuma Haraguchi
- Department of Molecular Pathology, Ehime University Graduate School of Medicine
| | - Sohei Kitazawa
- Department of Molecular Pathology, Ehime University Graduate School of Medicine
| |
Collapse
|
76
|
PHF6 Degrees of Separation: The Multifaceted Roles of a Chromatin Adaptor Protein. Genes (Basel) 2015; 6:325-52. [PMID: 26103525 PMCID: PMC4488667 DOI: 10.3390/genes6020325] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/12/2015] [Accepted: 06/16/2015] [Indexed: 12/13/2022] Open
Abstract
The importance of chromatin regulation to human disease is highlighted by the growing number of mutations identified in genes encoding chromatin remodeling proteins. While such mutations were first identified in severe developmental disorders, or in specific cancers, several genes have been implicated in both, including the plant homeodomain finger protein 6 (PHF6) gene. Indeed, germline mutations in PHF6 are the cause of the Börjeson–Forssman–Lehmann X-linked intellectual disability syndrome (BFLS), while somatic PHF6 mutations have been identified in T-cell acute lymphoblastic leukemia (T-ALL) and acute myeloid leukemia (AML). Studies from different groups over the last few years have made a significant impact towards a functional understanding of PHF6 protein function. In this review, we summarize the current knowledge of PHF6 with particular emphasis on how it interfaces with a distinct set of interacting partners and its functional roles in the nucleoplasm and nucleolus. Overall, PHF6 is emerging as a key chromatin adaptor protein critical to the regulation of neurogenesis and hematopoiesis.
Collapse
|
77
|
Ollion J, Loll F, Cochennec J, Boudier T, Escudé C. Proliferation-dependent positioning of individual centromeres in the interphase nucleus of human lymphoblastoid cell lines. Mol Biol Cell 2015; 26:2550-60. [PMID: 25947134 PMCID: PMC4571307 DOI: 10.1091/mbc.e14-05-1002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 04/27/2015] [Indexed: 01/01/2023] Open
Abstract
Centromeres are not randomly distributed in interphase nuclei. High-throughput imaging provides an accurate characterization of how their organization varies as a function of the proliferation state in human lymphoblastoid cells. The results suggest the existence of mechanisms that drive the nuclear positioning of centromeres. The cell nucleus is a highly organized structure and plays an important role in gene regulation. Understanding the mechanisms that sustain this organization is therefore essential for understanding genome function. Centromeric regions (CRs) of chromosomes have been known for years to adopt specific nuclear positioning patterns, but the significance of this observation is not yet completely understood. Here, using a combination of fluorescence in situ hybridization and immunochemistry on fixed human cells and high-throughput imaging, we directly and quantitatively investigated the nuclear positioning of specific human CRs. We observe differential attraction of individual CRs toward both the nuclear border and the nucleoli, the former being enhanced in nonproliferating cells and the latter being enhanced in proliferating cells. Similar positioning patterns are observed in two different lymphoblastoid cell lines. Moreover, the positioning of CRs differs from that of noncentromeric regions, and CRs display specific orientations within chromosome territories. These results suggest the existence of not-yet-characterized mechanisms that drive the nuclear positioning of CRs and therefore pave the way toward a better understanding of how CRs affect nuclear organization.
Collapse
Affiliation(s)
- Jean Ollion
- Institut National de la Santé et de la Recherche Médicale U1154, Centre National de la Recherche Scientifique UMR7196, Muséum National d'Histoire Naturelle, 75231 Paris, France
| | - François Loll
- Institut National de la Santé et de la Recherche Médicale U1154, Centre National de la Recherche Scientifique UMR7196, Muséum National d'Histoire Naturelle, 75231 Paris, France
| | - Julien Cochennec
- Institut National de la Santé et de la Recherche Médicale U1154, Centre National de la Recherche Scientifique UMR7196, Muséum National d'Histoire Naturelle, 75231 Paris, France
| | - Thomas Boudier
- Université Pierre et Marie Curie, Sorbonne Universités, 75005 Paris, France
| | - Christophe Escudé
- Institut National de la Santé et de la Recherche Médicale U1154, Centre National de la Recherche Scientifique UMR7196, Muséum National d'Histoire Naturelle, 75231 Paris, France
| |
Collapse
|
78
|
Alvarado S, Mak T, Liu S, Storey KB, Szyf M. Dynamic changes in global and gene-specific DNA methylation during hibernation in adult thirteen-lined ground squirrels, Ictidomys tridecemlineatus. ACTA ACUST UNITED AC 2015; 218:1787-95. [PMID: 25908059 DOI: 10.1242/jeb.116046] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 04/15/2015] [Indexed: 12/21/2022]
Abstract
Hibernating mammals conserve energy in the winter by undergoing prolonged bouts of torpor, interspersed with brief arousals back to euthermia. These bouts are accompanied by a suite of reversible physiological and biochemical changes; however, much remains to be discovered about the molecular mechanisms involved. Given the seasonal nature of hibernation, it stands to reason that underlying plastic epigenetic mechanisms should exist. One such form of epigenomic regulation involves the reversible modification of cytosine bases in DNA by methylation. DNA methylation is well known to be a mechanism that confers upon DNA its cellular identity during differentiation in response to innate developmental cues. However, it has recently been hypothesized that DNA methylation also acts as a mechanism for adapting genome function to changing external environmental and experiential signals over different time scales, including during adulthood. Here, we tested the hypothesis that DNA methylation is altered during hibernation in adult wild animals. This study evaluated global changes in DNA methylation in response to hibernation in the liver and skeletal muscle of thirteen-lined ground squirrels along with changes in expression of DNA methyltransferases (DNMT1/3B) and methyl binding domain proteins (MBDs). A reduction in global DNA methylation occurred in muscle during torpor phases whereas significant changes in DNMTs and MBDs were seen in both tissues. We also report dynamic changes in DNA methylation in the promoter of the myocyte enhancer factor 2C (mef2c) gene, a candidate regulator of metabolism in skeletal muscle. Taken together, these data show that genomic DNA methylation is dynamic across torpor-arousal bouts during winter hibernation, consistent with a role for this regulatory mechanism in contributing to the hibernation phenotype.
Collapse
Affiliation(s)
- Sebastian Alvarado
- Department of Pharmacology, McGill University, 3655 Sir William Osler Suite 1309, Montreal, QC, Canada H3G 1Y6; Sackler program in Epigenetics and Psychobiology at McGill University
| | - Timothy Mak
- Department of Pharmacology, McGill University, 3655 Sir William Osler Suite 1309, Montreal, QC, Canada H3G 1Y6; Sackler program in Epigenetics and Psychobiology at McGill University
| | - Sara Liu
- Department of Pharmacology, McGill University, 3655 Sir William Osler Suite 1309, Montreal, QC, Canada H3G 1Y6; Sackler program in Epigenetics and Psychobiology at McGill University
| | - Kenneth B Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6
| | - Moshe Szyf
- Department of Pharmacology, McGill University, 3655 Sir William Osler Suite 1309, Montreal, QC, Canada H3G 1Y6; Sackler program in Epigenetics and Psychobiology at McGill University
| |
Collapse
|
79
|
Abstract
Rett syndrome (RTT) is a severe neurological disorder caused by mutations in the X-linked gene MECP2 (methyl-CpG-binding protein 2). Two decades of research have fostered the view that MeCP2 is a multifunctional chromatin protein that integrates diverse aspects of neuronal biology. More recently, studies have focused on specific RTT-associated mutations within the protein. This work has yielded molecular insights into the critical functions of MeCP2 that promise to simplify our understanding of RTT pathology.
Collapse
Affiliation(s)
- Matthew J Lyst
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh EH9 3BF, UK
| | - Adrian Bird
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh EH9 3BF, UK
| |
Collapse
|
80
|
Chromatin-Driven Behavior of Topologically Associating Domains. J Mol Biol 2015; 427:608-25. [DOI: 10.1016/j.jmb.2014.09.013] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/17/2014] [Accepted: 09/23/2014] [Indexed: 12/19/2022]
|
81
|
Romero-Fernández I, Casas-Delucchi CS, Cano-Linares M, Arroyo M, Sánchez A, Cardoso MC, Marchal JA. Epigenetic modifications in sex heterochromatin of vole rodents. Chromosoma 2014; 124:341-51. [PMID: 25527445 DOI: 10.1007/s00412-014-0502-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/05/2014] [Accepted: 12/05/2014] [Indexed: 11/26/2022]
Abstract
The genome of some vole rodents contains large blocks of heterochromatin coupled to the sex chromosomes. While the DNA content of these heterochromatic blocks has been extensively analyzed, little is known about the epigenetic modifications controlling their structure and dynamics. To better understand its organization and functions within the nucleus, we have compared the distribution pattern of several epigenetic marks in cells from two species, Microtus agrestis and Microtus cabrerae. We first could show that the heterochromatic blocks are identifiable within the nuclei due to their AT enrichment detectable by DAPI staining. By immunostaining analyses, we demonstrated that enrichment in H3K9me3 and HP1, depletion of DNA methylation as well as H4K8ac and H3K4me2, are major conserved epigenetic features of this heterochromatin in both sex chromosomes. Furthermore, we provide evidence of transcriptional activity for some repeated DNAs in cultivated cells. These transcripts are partially polyadenylated and their levels are not altered during mitotic arrest. In summary, we show here that enrichment in H3K9me3 and HP1, DNA demethylation, and transcriptional activity are major epigenetic features of sex heterochromatin in vole rodents.
Collapse
Affiliation(s)
- I Romero-Fernández
- Department of Experimental Biology, University of Jaén, Jaén, E-23071, Spain
| | | | | | | | | | | | | |
Collapse
|
82
|
Menafra R, Stunnenberg HG. MBD2 and MBD3: elusive functions and mechanisms. Front Genet 2014; 5:428. [PMID: 25538734 PMCID: PMC4260518 DOI: 10.3389/fgene.2014.00428] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 11/21/2014] [Indexed: 02/05/2023] Open
Abstract
Deoxyribonucleic acid methylation is a long known epigenetic mark involved in many biological processes and the 'readers' of this mark belong to several distinct protein families that 'read' and 'translate' the methylation mark into a function. Methyl-CpG binding domain proteins belong to one of these families that are associated with transcriptional activation/repression, regulation of chromatin structure, pluripotency, development, and differentiation. Discovered decades ago, the systematic determination of the genomic binding sites of these readers and their epigenome make-up at a genome-wide level revealed the tip of the functional iceberg. This review focuses on two members of the methyl binding proteins, namely MBD2 and MBD3 that reside in very similar complexes, yet appear to have very different biological roles. We provide a comprehensive comparison of their genome-wide binding features and emerging roles in gene regulation.
Collapse
Affiliation(s)
- Roberta Menafra
- Department of Molecular Biology, Radboud University Nijmegen, Netherlands
| | | |
Collapse
|
83
|
Nishide K, Hirano T. Overlapping and non-overlapping functions of condensins I and II in neural stem cell divisions. PLoS Genet 2014; 10:e1004847. [PMID: 25474630 PMCID: PMC4256295 DOI: 10.1371/journal.pgen.1004847] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 10/24/2014] [Indexed: 11/18/2022] Open
Abstract
During development of the cerebral cortex, neural stem cells (NSCs) divide symmetrically to proliferate and asymmetrically to generate neurons. Although faithful segregation of mitotic chromosomes is critical for NSC divisions, its fundamental mechanism remains unclear. A class of evolutionarily conserved protein complexes, known as condensins, is thought to be central to chromosome assembly and segregation among eukaryotes. Here we report the first comprehensive genetic study of mammalian condensins, demonstrating that two different types of condensin complexes (condensins I and II) are both essential for NSC divisions and survival in mice. Simultaneous depletion of both condensins leads to severe defects in chromosome assembly and segregation, which in turn cause DNA damage and trigger p53-induced apoptosis. Individual depletions of condensins I and II lead to slower loss of NSCs compared to simultaneous depletion, but they display distinct mitotic defects: chromosome missegregation was observed more prominently in NSCs depleted of condensin II, whereas mitotic delays were detectable only in condensin I-depleted NSCs. Remarkably, NSCs depleted of condensin II display hyperclustering of pericentric heterochromatin and nucleoli, indicating that condensin II, but not condensin I, plays a critical role in establishing interphase nuclear architecture. Intriguingly, these defects are taken over to postmitotic neurons. Our results demonstrate that condensins I and II have overlapping and non-overlapping functions in NSCs, and also provide evolutionary insight into intricate balancing acts of the two condensin complexes.
Collapse
Affiliation(s)
- Kenji Nishide
- Chromosome Dynamics Laboratory, RIKEN, Hirosawa, Wako, Saitama, Japan
| | - Tatsuya Hirano
- Chromosome Dynamics Laboratory, RIKEN, Hirosawa, Wako, Saitama, Japan
- * E-mail:
| |
Collapse
|
84
|
Oyama K, El-Nachef D, Zhang Y, Sdek P, MacLellan WR. Epigenetic regulation of cardiac myocyte differentiation. Front Genet 2014; 5:375. [PMID: 25408700 PMCID: PMC4219506 DOI: 10.3389/fgene.2014.00375] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 10/07/2014] [Indexed: 12/04/2022] Open
Abstract
Cardiac myocytes (CMs) proliferate robustly during fetal life but withdraw permanently from the cell cycle soon after birth and undergo terminal differentiation. This cell cycle exit is associated with the upregulation of a host of adult cardiac-specific genes. The vast majority of adult CMs (ACMs) do not reenter cell cycle even if subjected to mitogenic stimuli. The basis for this irreversible cell cycle exit is related to the stable silencing of cell cycle genes specifically involved in the progression of G2/M transition and cytokinesis. Studies have begun to clarify the molecular basis for this stable gene repression and have identified epigenetic and chromatin structural changes in this process. In this review, we summarize the current understanding of epigenetic regulation of CM cell cycle and cardiac-specific gene expression with a focus on histone modifications and the role of retinoblastoma family members.
Collapse
Affiliation(s)
- Kyohei Oyama
- Division of Cardiology, Department of Medicine, Center for Cardiovascular Biology and Institute for Stem Cell and Regenerative Medicine, University of Washington Seattle, WA, USA
| | - Danny El-Nachef
- Division of Cardiology, Department of Medicine, Center for Cardiovascular Biology and Institute for Stem Cell and Regenerative Medicine, University of Washington Seattle, WA, USA
| | - Yiqiang Zhang
- Division of Cardiology, Department of Medicine, Center for Cardiovascular Biology and Institute for Stem Cell and Regenerative Medicine, University of Washington Seattle, WA, USA
| | - Patima Sdek
- Division of Cardiology, Department of Medicine, Center for Cardiovascular Biology and Institute for Stem Cell and Regenerative Medicine, University of Washington Seattle, WA, USA
| | - W Robb MacLellan
- Division of Cardiology, Department of Medicine, Center for Cardiovascular Biology and Institute for Stem Cell and Regenerative Medicine, University of Washington Seattle, WA, USA
| |
Collapse
|
85
|
Wieneke R, Labòria N, Rajan M, Kollmannsperger A, Natale F, Cardoso MC, Tampé R. Live-cell targeting of his-tagged proteins by multivalent N-nitrilotriacetic acid carrier complexes. J Am Chem Soc 2014; 136:13975-8. [PMID: 25238106 DOI: 10.1021/ja5063357] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Selective and fast labeling of proteins in living cells is a major challenge. Live-cell labeling techniques require high specificity, high labeling density, and cell permeability of the tagging molecule to target the protein of interest. Here we report on the site-specific, rapid, and efficient labeling of endogenous and recombinant histidine-tagged proteins in distinct subcellular compartments using cell-penetrating multivalent chelator carrier complexes. In vivo labeling was followed in real time in living cells, demonstrating a high specificity and high degree of colocalization in the crowded cellular environment.
Collapse
Affiliation(s)
- Ralph Wieneke
- Institute of Biochemistry, Goethe-University Frankfurt , Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany
| | | | | | | | | | | | | |
Collapse
|
86
|
Chu Y, Wang Y, Zhang G, Chen H, Dowdy SC, Xiong Y, Liu F, Zhang R, Li J, Jiang SW. Chromatin composition alterations and the critical role of MeCP2 for epigenetic silencing of progesterone receptor-B gene in endometrial cancers. Cell Mol Life Sci 2014; 71:3393-408. [PMID: 24531693 PMCID: PMC11113436 DOI: 10.1007/s00018-014-1580-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Revised: 01/17/2014] [Accepted: 01/28/2014] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To understand the epigenetic mechanism underlying the PR-B gene silencing in endometrial cancer (EC) cells, we compared the chromatin composition between transcriptionally active and silenced PR-B genes in EC cell lines and cancer tissues. METHODS Chromatin Immunoprecipitation (ChIP) assay was performed to measure MBD occupancy and histone acetylation/methylation in transcriptionally active and silenced PR-B genes. PR-B-positive/-negative, as well as epigenetic inhibitor-treated/-untreated EC cells were used as study models. Real-time polymerase chain reaction (PCR) and Western blot analysis were applied to measure the mRNA and protein levels of PR-B, MBD, and histones. RESULTS A close association among PR-B methylation, MBD binding and PR-B gene silencing was observed. Treatment with epigenetic inhibitors led to dynamic changes in the PR-B chromatin composition and gene expression. Increased H3/H4 acetylation and H3-K4 methylation, and decreased H3-K9 methylation were found to be associated with re-activation of silenced PR-B genes. MeCP2 knockdown resulted in a decreased MeCP2 binding to PR-B genes and an increased PR-B expression. ChIP analysis of MeCP2 binding to PR-B genes in the PR-B-positive/-negative EC samples confirmed the significant role of MeCP2 in PR-B silencing. CONCLUSION PR-B gene expression is regulated by a concerted action of epigenetic factors including DNA methylation, MBD binding, and histone modifications. MeCP2 occupancy of PR-B genes plays a critical role in PR-B gene silencing. These findings enriched our knowledge of the epigenetic regulation of PR-B expression in EC, and suggested that the epigenetic re-activation of PR-B could be explored as a potential strategy to sensitize the PR-B-negative endometrial cancers to progestational therapy.
Collapse
Affiliation(s)
- Yongli Chu
- Yantai Yuhuangding Hospital Affiliated to Qingdao University, Yantai, 264000 China
| | - Yanlin Wang
- Department of Reproductive Medicine, Binzhou Medical University Hospital, Binzhou, 256603 China
| | - Guanghua Zhang
- Tianjin Medical University Cancer Hospital, Tianjin, 300060 China
| | - Haibin Chen
- Department of Histology and Embryology, Shantou University Medical College, Guangdong, China
| | - Sean C. Dowdy
- Department of Obstetrics and Gynecology, Mayo Clinic and Mayo Medical School, Rochester, MN 55905 USA
| | - Yuning Xiong
- Department of Obstetrics and Gynecology, Mayo Clinic and Mayo Medical School, Rochester, MN 55905 USA
| | - Fengming Liu
- Department of Research and Development, Guangxi Medicinal Botanical Institute, Nanning, 530024 China
| | - Run Zhang
- Department of Biomedical Science, Mercer University School of Medicine, Savannah, GA 31404 USA
| | - Jinping Li
- Department of Obstetrics and Gynecology, Mayo Clinic and Mayo Medical School, Rochester, MN 55905 USA
- Curtis & Elizabeth Anderson Cancer Institute, Memorial Health University Medical Center, 4700 Waters Avenue, Savannah, GA 31404 USA
- Department of Biomedical Science, Mercer University School of Medicine, Savannah, GA 31404 USA
| | - Shi-Wen Jiang
- Department of Obstetrics and Gynecology, Mayo Clinic and Mayo Medical School, Rochester, MN 55905 USA
- Curtis & Elizabeth Anderson Cancer Institute, Memorial Health University Medical Center, 4700 Waters Avenue, Savannah, GA 31404 USA
- Department of Obstetrics and Gynecology, Memorial Health University Medical Center, 4700 Waters Avenue, Savannah, GA 31404 USA
- Department of Biomedical Science, Mercer University School of Medicine, Savannah, GA 31404 USA
| |
Collapse
|
87
|
Müller-Ott K, Erdel F, Matveeva A, Mallm JP, Rademacher A, Hahn M, Bauer C, Zhang Q, Kaltofen S, Schotta G, Höfer T, Rippe K. Specificity, propagation, and memory of pericentric heterochromatin. Mol Syst Biol 2014; 10:746. [PMID: 25134515 PMCID: PMC4299515 DOI: 10.15252/msb.20145377] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The cell establishes heritable patterns of active and silenced chromatin via interacting factors
that set, remove, and read epigenetic marks. To understand how the underlying networks operate, we
have dissected transcriptional silencing in pericentric heterochromatin (PCH) of mouse fibroblasts.
We assembled a quantitative map for the abundance and interactions of 16 factors related to PCH in
living cells and found that stably bound complexes of the histone methyltransferase SUV39H1/2
demarcate the PCH state. From the experimental data, we developed a predictive mathematical model
that explains how chromatin-bound SUV39H1/2 complexes act as nucleation sites and propagate a
spatially confined PCH domain with elevated histone H3 lysine 9 trimethylation levels via chromatin
dynamics. This “nucleation and looping” mechanism is particularly robust toward
transient perturbations and stably maintains the PCH state. These features make it an attractive
model for establishing functional epigenetic domains throughout the genome based on the localized
immobilization of chromatin-modifying enzymes.
Collapse
Affiliation(s)
- Katharina Müller-Ott
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Research Group Genome Organization & Function, Heidelberg, Germany
| | - Fabian Erdel
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Research Group Genome Organization & Function, Heidelberg, Germany
| | - Anna Matveeva
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Division Theoretical Systems Biology, Heidelberg, Germany
| | - Jan-Philipp Mallm
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Research Group Genome Organization & Function, Heidelberg, Germany
| | - Anne Rademacher
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Research Group Genome Organization & Function, Heidelberg, Germany
| | - Matthias Hahn
- Munich Center for Integrated Protein Science and Adolf Butenandt Institute, Ludwig Maximilians University, Munich, Germany
| | - Caroline Bauer
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Research Group Genome Organization & Function, Heidelberg, Germany
| | - Qin Zhang
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Division Theoretical Systems Biology, Heidelberg, Germany
| | - Sabine Kaltofen
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Research Group Genome Organization & Function, Heidelberg, Germany
| | - Gunnar Schotta
- Munich Center for Integrated Protein Science and Adolf Butenandt Institute, Ludwig Maximilians University, Munich, Germany
| | - Thomas Höfer
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Division Theoretical Systems Biology, Heidelberg, Germany
| | - Karsten Rippe
- Deutsches Krebsforschungszentrum (DKFZ) and BioQuant, Research Group Genome Organization & Function, Heidelberg, Germany
| |
Collapse
|
88
|
Scherthan H, Schöfisch K, Dell T, Illner D. Contrasting behavior of heterochromatic and euchromatic chromosome portions and pericentric genome separation in pre-bouquet spermatocytes of hybrid mice. Chromosoma 2014; 123:609-24. [PMID: 25119530 PMCID: PMC4226931 DOI: 10.1007/s00412-014-0479-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/03/2014] [Accepted: 07/16/2014] [Indexed: 12/22/2022]
Abstract
The spatial distribution of parental genomes has attracted much interest because intranuclear chromosome distribution can modulate the transcriptome of cells and influence the efficacy of meiotic homologue pairing. Pairing of parental chromosomes is imperative to sexual reproduction as it translates into homologue segregation and genome haploidization to counteract the genome doubling at fertilization. Differential FISH tagging of parental pericentromeric genome portions and specific painting of euchromatic chromosome arms in Mus musculus (MMU) × Mus spretus (MSP) hybrid spermatogenesis disclosed a phase of homotypic non-homologous pericentromere clustering that led to parental pericentric genome separation from the pre-leptoteneup to zygotene stages. Preferential clustering of MMU pericentromeres correlated with particular enrichment of epigenetic marks (H3K9me3), HP1-γ and structural maintenance of chromosomes SMC6 complex proteins at the MMU major satellite DNA repeats. In contrast to the separation of heterochromatic pericentric genome portions, the euchromatic arms of homeologous chromosomes showed considerable presynaptic pairing already during leptotene stage of all mice investigated. Pericentric genome separation was eventually disbanded by telomere clustering that concentrated both parental pericentric genome portions in a limited nuclear sector of the bouquet nucleus. Our data disclose the differential behavior of pericentromeric heterochromatin and the euchromatic portions of the parental genomes during homologue search. Homotypic pericentromere clustering early in prophase I may contribute to the exclusion of large repetitive DNA domains from homology search, while the telomere bouquet congregates and registers spatially separated portions of the genome to fuel synapsis initiation and high levels of homologue pairing, thus contributing to the fidelity of meiosis and reproduction.
Collapse
Affiliation(s)
- Harry Scherthan
- Institut für Radiobiologie der Bundeswehr in Verb. mit der Univ. Ulm, 80937, München, Germany,
| | | | | | | |
Collapse
|
89
|
Song C, Feodorova Y, Guy J, Peichl L, Jost KL, Kimura H, Cardoso MC, Bird A, Leonhardt H, Joffe B, Solovei I. DNA methylation reader MECP2: cell type- and differentiation stage-specific protein distribution. Epigenetics Chromatin 2014; 7:17. [PMID: 25170345 PMCID: PMC4148084 DOI: 10.1186/1756-8935-7-17] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 07/23/2014] [Indexed: 11/21/2022] Open
Abstract
Background Methyl-CpG binding protein 2 (MECP2) is a protein that specifically binds methylated DNA, thus regulating transcription and chromatin organization. Mutations in the gene have been identified as the principal cause of Rett syndrome, a severe neurological disorder. Although the role of MECP2 has been extensively studied in nervous tissues, still very little is known about its function and cell type specific distribution in other tissues. Results Using immunostaining on tissue cryosections, we characterized the distribution of MECP2 in 60 cell types of 16 mouse neuronal and non-neuronal tissues. We show that MECP2 is expressed at a very high level in all retinal neurons except rod photoreceptors. The onset of its expression during retina development coincides with massive synapse formation. In contrast to astroglia, retinal microglial cells lack MECP2, similar to microglia in the brain, cerebellum, and spinal cord. MECP2 is also present in almost all non-neural cell types, with the exception of intestinal epithelial cells, erythropoietic cells, and hair matrix keratinocytes. Our study demonstrates the role of MECP2 as a marker of the differentiated state in all studied cells other than oocytes and spermatogenic cells. MECP2-deficient male (Mecp2-/y) mice show no apparent defects in the morphology and development of the retina. The nuclear architecture of retinal neurons is also unaffected as the degree of chromocenter fusion and the distribution of major histone modifications do not differ between Mecp2-/y and Mecp2wt mice. Surprisingly, the absence of MECP2 is not compensated by other methyl-CpG binding proteins. On the contrary, their mRNA levels were downregulated in Mecp2-/y mice. Conclusions MECP2 is almost universally expressed in all studied cell types with few exceptions, including microglia. MECP2 deficiency does not change the nuclear architecture and epigenetic landscape of retinal cells despite the missing compensatory expression of other methyl-CpG binding proteins. Furthermore, retinal development and morphology are also preserved in Mecp2-null mice. Our study reveals the significance of MECP2 function in cell differentiation and sets the basis for future investigations in this direction.
Collapse
Affiliation(s)
- Congdi Song
- Department of Biology II, Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Yana Feodorova
- Department of Biology II, Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Jacky Guy
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, EH9 3JR Edinburgh, UK
| | - Leo Peichl
- Max Planck Institute for Brain Research, Max-von-Laue-Str. 4, Frankfurt am Main 60438, Germany
| | - Katharina Laurence Jost
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstr. 10, Darmstadt 64287, Germany
| | - Hiroshi Kimura
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, 565-0871 Suita, Osaka, Japan
| | - Maria Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstr. 10, Darmstadt 64287, Germany
| | - Adrian Bird
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, EH9 3JR Edinburgh, UK
| | - Heinrich Leonhardt
- Department of Biology II, Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Boris Joffe
- Department of Biology II, Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Irina Solovei
- Department of Biology II, Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| |
Collapse
|
90
|
Abstract
Rett syndrome (RTT) is a severe and progressive neurological disorder, which mainly affects young females. Mutations of the methyl-CpG binding protein 2 (MECP2) gene are the most prevalent cause of classical RTT cases. MECP2 mutations or altered expression are also associated with a spectrum of neurodevelopmental disorders such as autism spectrum disorders with recent links to fetal alcohol spectrum disorders. Collectively, MeCP2 relation to these neurodevelopmental disorders highlights the importance of understanding the molecular mechanisms by which MeCP2 impacts brain development, mental conditions, and compromised brain function. Since MECP2 mutations were discovered to be the primary cause of RTT, a significant progress has been made in the MeCP2 research, with respect to the expression, function and regulation of MeCP2 in the brain and its contribution in RTT pathogenesis. To date, there have been intensive efforts in designing effective therapeutic strategies for RTT benefiting from mouse models and cells collected from RTT patients. Despite significant progress in MeCP2 research over the last few decades, there is still a knowledge gap between the in vitro and in vivo research findings and translating these findings into effective therapeutic interventions in human RTT patients. In this review, we will provide a synopsis of Rett syndrome as a severe neurological disorder and will discuss the role of MeCP2 in RTT pathophysiology.
Collapse
|
91
|
Thanisch K, Schneider K, Morbitzer R, Solovei I, Lahaye T, Bultmann S, Leonhardt H. Targeting and tracing of specific DNA sequences with dTALEs in living cells. Nucleic Acids Res 2013; 42:e38. [PMID: 24371265 PMCID: PMC3973286 DOI: 10.1093/nar/gkt1348] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Epigenetic regulation of gene expression involves, besides DNA and histone modifications, the relative positioning of DNA sequences within the nucleus. To trace specific DNA sequences in living cells, we used programmable sequence-specific DNA binding of designer transcription activator-like effectors (dTALEs). We designed a recombinant dTALE (msTALE) with variable repeat domains to specifically bind a 19-bp target sequence of major satellite DNA. The msTALE was fused with green fluorescent protein (GFP) and stably expressed in mouse embryonic stem cells. Hybridization with a major satellite probe (3D-fluorescent in situ hybridization) and co-staining for known cellular structures confirmed in vivo binding of the GFP-msTALE to major satellite DNA present at nuclear chromocenters. Dual tracing of major satellite DNA and the replication machinery throughout S-phase showed co-localization during mid to late S-phase, directly demonstrating the late replication timing of major satellite DNA. Fluorescence bleaching experiments indicated a relatively stable but still dynamic binding, with mean residence times in the range of minutes. Fluorescently labeled dTALEs open new perspectives to target and trace DNA sequences and to monitor dynamic changes in subnuclear positioning as well as interactions with functional nuclear structures during cell cycle progression and cellular differentiation.
Collapse
Affiliation(s)
- Katharina Thanisch
- Department of Biology II, Humanbiology and Bioimaging, Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany and Department of Biology I, Genetics, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany
| | | | | | | | | | | | | |
Collapse
|
92
|
Yasui DH, Gonzales ML, Aflatooni JO, Crary FK, Hu DJ, Gavino BJ, Golub MS, Vincent JB, Carolyn Schanen N, Olson CO, Rastegar M, Lasalle JM. Mice with an isoform-ablating Mecp2 exon 1 mutation recapitulate the neurologic deficits of Rett syndrome. Hum Mol Genet 2013; 23:2447-58. [PMID: 24352790 DOI: 10.1093/hmg/ddt640] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mutations in MECP2 cause the neurodevelopmental disorder Rett syndrome (RTT OMIM 312750). Alternative inclusion of MECP2/Mecp2 exon 1 with exons 3 and 4 encodes MeCP2-e1 or MeCP2-e2 protein isoforms with unique amino termini. While most MECP2 mutations are located in exons 3 and 4 thus affecting both isoforms, MECP2 exon 1 mutations but not exon 2 mutations have been identified in RTT patients, suggesting that MeCP2-e1 deficiency is sufficient to cause RTT. As expected, genetic deletion of Mecp2 exons 3 and/or 4 recapitulates RTT-like neurologic defects in mice. However, Mecp2 exon 2 knockout mice have normal neurologic function. Here, a naturally occurring MECP2 exon 1 mutation is recapitulated in a mouse model by genetic engineering. A point mutation in the translational start codon of Mecp2 exon 1, transmitted through the germline, ablates MeCP2-e1 translation while preserving MeCP2-e2 production in mouse brain. The resulting MeCP2-e1 deficient mice developed forelimb stereotypy, hindlimb clasping, excessive grooming and hypo-activity prior to death between 7 and 31 weeks. MeCP2-e1 deficient mice also exhibited abnormal anxiety, sociability and ambulation. Despite MeCP2-e1 and MeCP2-e2 sharing, 96% amino acid identity, differences were identified. A fraction of phosphorylated MeCP2-e1 differed from the bulk of MeCP2 in subnuclear localization and co-factor interaction. Furthermore, MeCP2-e1 exhibited enhanced stability compared with MeCP2-e2 in neurons. Therefore, MeCP2-e1 deficient mice implicate MeCP2-e1 as the sole contributor to RTT with non-redundant functions.
Collapse
Affiliation(s)
- Dag H Yasui
- Department of Medical Microbiology and Immunology, UC Davis, Davis, CA, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
93
|
Riviere G, Wu GC, Fellous A, Goux D, Sourdaine P, Favrel P. DNA methylation is crucial for the early development in the Oyster C. gigas. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2013; 15:739-53. [PMID: 23877618 DOI: 10.1007/s10126-013-9523-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 06/04/2013] [Indexed: 05/02/2023]
Abstract
In vertebrates, epigenetic modifications influence gene transcription, and an appropriate DNA methylation is critical in development. Indeed, a precise temporal and spatial pattern of early gene expression is mandatory for a normal embryogenesis. However, such a regulation and its underlying mechanisms remain poorly understood in more distant organisms such as Lophotrochozoa. Thus, despite DNA in the oyster genome being methylated, the role of DNA methylation in development is unknown. To clarify this point, oyster genomic DNA was examined during early embryogenesis and found differentially methylated. Reverse transcriptase quantitative polymerase chain reaction indicated stage-specific levels of transcripts encoding DNA-methyltransferase (DNMT) and methyl-binding domain proteins. In addition, as highlighted by electronic microscopy and immunohistochemistry, the DNMT inhibitor 5-aza-cytidine induced alterations in the quantity and the localisation of methylated DNA and severe dose-dependent development alterations and was lethal after zygotic genome reinitiation. Furthermore, methyl-DNA-immunoprecipitation-quantitative polymerase chain reaction revealed that the transcription level of most of the homeobox gene orthologues examined, but not of the other early genes investigated, was inversely correlated with their specific DNA methylation. Altogether, our results demonstrate that DNA methylation influences gene expression in Crassostrea gigas and is critical for oyster development, possibly by specifically controlling the transcription level of homeobox orthologues. These findings provide evidence for the importance of epigenetic regulation of development in Lophotrochozoans and bring new insights into the early life of C. gigas, one of the most important aquaculture resources worldwide.
Collapse
Affiliation(s)
- Guillaume Riviere
- Biologie des Organismes Marins et des Ecosystèmes Associés (BioMEA) Esplanade de la paix, Université de Caen Basse-Normandie, 14032, Caen Cedex, France,
| | | | | | | | | | | |
Collapse
|
94
|
A role for MeCP2 in switching gene activity via chromatin unfolding and HP1γ displacement. PLoS One 2013; 8:e69347. [PMID: 23935992 PMCID: PMC3720725 DOI: 10.1371/journal.pone.0069347] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 06/07/2013] [Indexed: 11/19/2022] Open
Abstract
Methyl-CpG-binding protein 2 (MeCP2) is generally considered to act as a transcriptional repressor, whereas recent studies suggest that MeCP2 is also involved in transcription activation. To gain insight into this dual function of MeCP2, we assessed the impact of MeCP2 on higher-order chromatin structure in living cells using mammalian cell systems harbouring a lactose operator and reporter gene-containing chromosomal domain to assess the effect of lactose repressor-tagged MeCP2 (and separate MeCP2 domains) binding in living cells. Our data reveal that targeted binding of MeCP2 elicits extensive chromatin unfolding. MeCP2-induced chromatin unfolding is triggered independently of the methyl-cytosine-binding domain. Interestingly, MeCP2 binding triggers the loss of HP1γ at the chromosomal domain and an increased HP1γ mobility, which is not observed for HP1α and HP1β. Surprisingly, MeCP2-induced chromatin unfolding is not associated with transcriptional activation. Our study suggests a novel role for MeCP2 in reorganizing chromatin to facilitate a switch in gene activity.
Collapse
|
95
|
Ritland Politz JC, Scalzo D, Groudine M. Something silent this way forms: the functional organization of the repressive nuclear compartment. Annu Rev Cell Dev Biol 2013; 29:241-70. [PMID: 23834025 PMCID: PMC3999972 DOI: 10.1146/annurev-cellbio-101512-122317] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The repressive compartment of the nucleus is comprised primarily of telomeric and centromeric regions, the silent portion of ribosomal RNA genes, the majority of transposable element repeats, and facultatively repressed genes specific to different cell types. This compartment localizes into three main regions: the peripheral heterochromatin, perinucleolar heterochromatin, and pericentromeric heterochromatin. Both chromatin remodeling proteins and transcription of noncoding RNAs are involved in maintenance of repression in these compartments. Global reorganization of the repressive compartment occurs at each cell division, during early development, and during terminal differentiation. Differential action of chromatin remodeling complexes and boundary element looping activities are involved in mediating these organizational changes. We discuss the evidence that heterochromatin formation and compartmentalization may drive nuclear organization.
Collapse
Affiliation(s)
| | - David Scalzo
- Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
| | - Mark Groudine
- Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
| |
Collapse
|
96
|
Cao K, Lailler N, Zhang Y, Kumar A, Uppal K, Liu Z, Lee EK, Wu H, Medrzycki M, Pan C, Ho PY, Cooper GP, Dong X, Bock C, Bouhassira EE, Fan Y. High-resolution mapping of h1 linker histone variants in embryonic stem cells. PLoS Genet 2013; 9:e1003417. [PMID: 23633960 PMCID: PMC3636266 DOI: 10.1371/journal.pgen.1003417] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 02/13/2013] [Indexed: 02/07/2023] Open
Abstract
H1 linker histones facilitate higher-order chromatin folding and are essential for mammalian development. To achieve high-resolution mapping of H1 variants H1d and H1c in embryonic stem cells (ESCs), we have established a knock-in system and shown that the N-terminally tagged H1 proteins are functionally interchangeable to their endogenous counterparts in vivo. H1d and H1c are depleted from GC- and gene-rich regions and active promoters, inversely correlated with H3K4me3, but positively correlated with H3K9me3 and associated with characteristic sequence features. Surprisingly, both H1d and H1c are significantly enriched at major satellites, which display increased nucleosome spacing compared with bulk chromatin. While also depleted at active promoters and enriched at major satellites, overexpressed H10 displays differential binding patterns in specific repetitive sequences compared with H1d and H1c. Depletion of H1c, H1d, and H1e causes pericentric chromocenter clustering and de-repression of major satellites. These results integrate the localization of an understudied type of chromatin proteins, namely the H1 variants, into the epigenome map of mouse ESCs, and we identify significant changes at pericentric heterochromatin upon depletion of this epigenetic mark. Embryonic stem cells (ESCs) possess unique chromatin and epigenetic signatures, which are important in defining the identity and genome plasticity of pluripotent stem cells. Although ESC epigenomes have been extensively characterized, the genome localization of histone H1 variants, the chromatin structural proteins facilitating higher-order chromatin folding, remains elusive. Linker histone H1 is essential for mammalian development and regulates the expression of specific genes in ESCs. Here, by using a knock-in system coupled with ChIP–seq, we first achieve the high resolution mapping of two H1 variants on a genome-wide scale in mouse ESCs. Our study reveals the correlations of this underexplored histone family with other epigenetic marks and genome attributes. Surprisingly, we identify a dramatic enrichment of H1d and H1c at major satellite sequences. H10, mapped using an overexpressing ESC line, shows similar features at active promoters but differential binding at repetitive sequences compared with H1d and H1c. Furthermore, using mutant ESCs that are deficient for multiple H1 variants, we demonstrate the role of H1 in chromocenter clustering and transcriptional repression of major satellites. Thus, these results connect this important repressive mark with the well understood ESC epigenome and identify novel functions of H1 in mammalian genome organization.
Collapse
Affiliation(s)
- Kaixiang Cao
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Nathalie Lailler
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Yunzhe Zhang
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Ashwath Kumar
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Karan Uppal
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Zheng Liu
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Eva K. Lee
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Hongwei Wu
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Magdalena Medrzycki
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Chenyi Pan
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Po-Yi Ho
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Guy P. Cooper
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Xiao Dong
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Christoph Bock
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
- Max Planck Institute for Informatics, Saarbrücken, Germany
| | - Eric E. Bouhassira
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Yuhong Fan
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- * E-mail:
| |
Collapse
|
97
|
Sdek P, Oyama K, Angelis E, Chan SS, Schenke-Layland K, MacLellan WR. Epigenetic regulation of myogenic gene expression by heterochromatin protein 1 alpha. PLoS One 2013; 8:e58319. [PMID: 23505487 PMCID: PMC3594309 DOI: 10.1371/journal.pone.0058319] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 02/02/2013] [Indexed: 12/17/2022] Open
Abstract
Heterochromatin protein 1 (HP1) is an essential heterochromatin-associated protein typically involved in the epigenetic regulation of gene silencing. However, recent reports have demonstrated that HP1 can also activate gene expression in certain contexts including differentiation. To explore the role of each of the three mammalian HP1 family members (α, β and γ) in skeletal muscle, their expression was individually disrupted in differentiating skeletal myocytes. Among the three isoforms of HP1, HP1α was specifically required for myogenic gene expression in myoblasts only. Knockdown of HP1α led to a defect in transcription of skeletal muscle-specific genes including Lbx1, MyoD and myogenin. HP1α binds to the genomic region of myogenic genes and depletion of HP1α results in a paradoxical increase in histone H3 lysine 9 trimethylation (H3K9me3) at these sites. JHDM3A, a H3K9 demethylase also binds to myogenic gene's genomic regions in myoblasts in a HP1α-dependent manner. JHDM3A interacts with HP1α and knockdown of JHDM3A in myoblasts recapitulates the decreased myogenic gene transcription seen with HP1α depletion. These results propose a novel mechanism for HP1α-dependent gene activation by interacting with the demethylase JHDM3A and that HP1α is required for maintenance of myogenic gene expression in myoblasts.
Collapse
Affiliation(s)
- Patima Sdek
- Departments of Medicine/Cardiology, Center for Cardiovascular Biology, Institute for Stem Cell Research, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Kyohei Oyama
- Departments of Medicine/Cardiology, Center for Cardiovascular Biology, Institute for Stem Cell Research, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Ekaterini Angelis
- Departments of Medicine/Cardiology, Center for Cardiovascular Biology, Institute for Stem Cell Research, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Shing S. Chan
- Departments of Medicine/Cardiology, Center for Cardiovascular Biology, Institute for Stem Cell Research, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Katja Schenke-Layland
- Departments of Medicine/Cardiology, Center for Cardiovascular Biology, Institute for Stem Cell Research, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - W. Robb MacLellan
- Departments of Medicine/Cardiology, Center for Cardiovascular Biology, Institute for Stem Cell Research, University of Washington School of Medicine, Seattle, Washington, United States of America
- * E-mail:
| |
Collapse
|
98
|
Becker A, Allmann L, Hofstätter M, Casà V, Weber P, Lehmkuhl A, Herce HD, Cardoso MC. Direct homo- and hetero-interactions of MeCP2 and MBD2. PLoS One 2013; 8:e53730. [PMID: 23335972 PMCID: PMC3546041 DOI: 10.1371/journal.pone.0053730] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 12/04/2012] [Indexed: 01/11/2023] Open
Abstract
Epigenetic marks like methylation of cytosines at CpG dinucleotides are essential for mammalian development and play a major role in the regulation of gene expression and chromatin architecture. The methyl-cytosine binding domain (MBD) protein family recognizes and translates this methylation mark. We have recently shown that the level of MeCP2 and MBD2, two members of the MBD family, increased during differentiation and their ectopic expression induced heterochromatin clustering in vivo. As oligomerization of these MBD proteins could constitute a factor contributing to the chromatin clustering effect, we addressed potential associations among the MBD family performing a series of different interaction assays in vitro as well as in vivo. Using recombinant purified MBDs we found that MeCP2 and MBD2 showed the stronger self and cross association as compared to the other family members. Besides demonstrating that these homo- and hetero-interactions occur in the absence of DNA, we could confirm them in mammalian cells using co-immunoprecipitation analysis. Employing a modified form of the fluorescent two-hybrid protein-protein interaction assay, we could clearly visualize these associations in single cells in vivo. Deletion analysis indicated that the region of MeCP2 comprising amino acids 163–309 as well the first 152 amino acids of MBD2 are the domains responsible for MeCP2 and MBD2 associations. Our results strengthen the possibility that MeCP2 and MBD2 direct interactions could crosslink chromatin fibers and therefore give novel insight into the molecular mechanism of MBD mediated global heterochromatin architecture.
Collapse
Affiliation(s)
- Annette Becker
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Lena Allmann
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | | | - Valentina Casà
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Patrick Weber
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Anne Lehmkuhl
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Henry D. Herce
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - M. Cristina Cardoso
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
- * E-mail:
| |
Collapse
|
99
|
Herce HD, Deng W, Helma J, Leonhardt H, Cardoso MC. Visualization and targeted disruption of protein interactions in living cells. Nat Commun 2013; 4:2660. [PMID: 24154492 PMCID: PMC3826628 DOI: 10.1038/ncomms3660] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 09/23/2013] [Indexed: 11/10/2022] Open
Abstract
Protein-protein interactions are the basis of all processes in living cells, but most studies of these interactions rely on biochemical in vitro assays. Here we present a simple and versatile fluorescent-three-hybrid (F3H) strategy to visualize and target protein-protein interactions. A high-affinity nanobody anchors a GFP-fusion protein of interest at a defined cellular structure and the enrichment of red-labelled interacting proteins is measured at these sites. With this approach, we visualize the p53-HDM2 interaction in living cells and directly monitor the disruption of this interaction by Nutlin 3, a drug developed to boost p53 activity in cancer therapy. We further use this approach to develop a cell-permeable vector that releases a highly specific peptide disrupting the p53 and HDM2 interaction. The availability of multiple anchor sites and the simple optical readout of this nanobody-based capture assay enable systematic and versatile analyses of protein-protein interactions in practically any cell type and species.
Collapse
Affiliation(s)
- Henry D. Herce
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
- These authors contributed equally to this work
| | - Wen Deng
- Department of Biology II, Center for Integrated Protein Science Munich, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany
- These authors contributed equally to this work
| | - Jonas Helma
- Department of Biology II, Center for Integrated Protein Science Munich, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany
| | - Heinrich Leonhardt
- Department of Biology II, Center for Integrated Protein Science Munich, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany
| | - M. Cristina Cardoso
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| |
Collapse
|
100
|
Dubinska-Magiera M, Zaremba-Czogalla M, Rzepecki R. Muscle development, regeneration and laminopathies: how lamins or lamina-associated proteins can contribute to muscle development, regeneration and disease. Cell Mol Life Sci 2012; 70:2713-41. [PMID: 23138638 PMCID: PMC3708280 DOI: 10.1007/s00018-012-1190-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 09/28/2012] [Accepted: 10/03/2012] [Indexed: 12/22/2022]
Abstract
The aim of this review article is to evaluate the current knowledge on associations between muscle formation and regeneration and components of the nuclear lamina. Lamins and their partners have become particularly intriguing objects of scientific interest since it has been observed that mutations in genes coding for these proteins lead to a wide range of diseases called laminopathies. For over the last 10 years, various laboratories worldwide have tried to explain the pathogenesis of these rare disorders. Analyses of the distinct aspects of laminopathies resulted in formulation of different hypotheses regarding the mechanisms of the development of these diseases. In the light of recent discoveries, A-type lamins—the main building blocks of the nuclear lamina—together with other key elements, such as emerin, LAP2α and nesprins, seem to be of great importance in the modulation of various signaling pathways responsible for cellular differentiation and proliferation.
Collapse
Affiliation(s)
- Magda Dubinska-Magiera
- Department of Animal Developmental Biology, University of Wroclaw, 21 Sienkiewicza Street, 50-335, Wroclaw, Poland
| | | | | |
Collapse
|