1
|
Arroyo M, Casas-Delucchi CS, Pabba MK, Prorok P, Pradhan SK, Rausch C, Lehmkuhl A, Maiser A, Buschbeck M, Pasque V, Bernstein E, Luck K, Cardoso MC. Histone variant macroH2A1 regulates synchronous firing of replication origins in the inactive X chromosome. Nucleic Acids Res 2024:gkae734. [PMID: 39189450 DOI: 10.1093/nar/gkae734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 08/07/2024] [Accepted: 08/14/2024] [Indexed: 08/28/2024] Open
Abstract
MacroH2A has been linked to transcriptional silencing, cell identity, and is a hallmark of the inactive X chromosome (Xi). However, it remains unclear whether macroH2A plays a role in DNA replication. Using knockdown/knockout cells for each macroH2A isoform, we show that macroH2A-containing nucleosomes slow down replication progression rate in the Xi reflecting the higher nucleosome stability. Moreover, macroH2A1, but not macroH2A2, regulates the number of nano replication foci in the Xi, and macroH2A1 downregulation increases DNA loop sizes corresponding to replicons. This relates to macroH2A1 regulating replicative helicase loading during G1 by interacting with it. We mapped this interaction to a phenylalanine in macroH2A1 that is not conserved in macroH2A2 and the C-terminus of Mcm3 helicase subunit. We propose that macroH2A1 enhances the licensing of pre-replication complexes via DNA helicase interaction and loading onto the Xi.
Collapse
Affiliation(s)
- Maria Arroyo
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Corella S Casas-Delucchi
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Maruthi K Pabba
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Paulina Prorok
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Sunil K Pradhan
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Cathia Rausch
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Anne Lehmkuhl
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Andreas Maiser
- Faculty of Biology and Center for Molecular Biosystems (BioSysM), Human Biology and BioImaging, LMU Munich, Munich 81377, Germany
| | - Marcus Buschbeck
- Program of Myeloid Neoplasms, Program of Applied Epigenetics, Josep Carreras Leukaemia Research Institute (IJC), Germans Trias i Pujol Research Institute (IGTP), Campus Can Ruti, Camí de les Escoles, 08916 Badalona, Barcelona, Spain
| | - Vincent Pasque
- Department of Development and Regeneration, Leuven Stem Cell Institute, Leuven Institute for Single-Cell Omics (LISCO), KU Leuven-University of Leuven, 3000 Leuven, Belgium
| | - Emily Bernstein
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, Tisch Cancer Institute, NY, NY 10029, USA
| | - Katja Luck
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany
| | - M Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| |
Collapse
|
2
|
Battista S, Fedele M, Secco L, Ingo AMD, Sgarra R, Manfioletti G. Binding to the Other Side: The AT-Hook DNA-Binding Domain Allows Nuclear Factors to Exploit the DNA Minor Groove. Int J Mol Sci 2024; 25:8863. [PMID: 39201549 PMCID: PMC11354804 DOI: 10.3390/ijms25168863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Revised: 08/08/2024] [Accepted: 08/10/2024] [Indexed: 09/02/2024] Open
Abstract
The "AT-hook" is a peculiar DNA-binding domain that interacts with DNA in the minor groove in correspondence to AT-rich sequences. This domain has been first described in the HMGA protein family of architectural factors and later in various transcription factors and chromatin proteins, often in association with major groove DNA-binding domains. In this review, using a literature search, we identified about one hundred AT-hook-containing proteins, mainly chromatin proteins and transcription factors. After considering the prototypes of AT-hook-containing proteins, the HMGA family, we review those that have been studied in more detail and that have been involved in various pathologies with a particular focus on cancer. This review shows that the AT-hook is a domain that gives proteins not only the ability to interact with DNA but also with RNA and proteins. This domain can have enzymatic activity and can influence the activity of the major groove DNA-binding domain and chromatin docking modules when present, and its activity can be modulated by post-translational modifications. Future research on the function of AT-hook-containing proteins will allow us to better decipher their function and contribution to the different pathologies and to eventually uncover their mutual influences.
Collapse
Affiliation(s)
- Sabrina Battista
- Institute of Experimental Endocrinology and Oncology “G. Salvatore” (IEOS), National Research Council (CNR), 80131 Naples, Italy; (S.B.); (M.F.)
| | - Monica Fedele
- Institute of Experimental Endocrinology and Oncology “G. Salvatore” (IEOS), National Research Council (CNR), 80131 Naples, Italy; (S.B.); (M.F.)
| | - Luca Secco
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (L.S.); (A.M.D.I.)
| | | | - Riccardo Sgarra
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (L.S.); (A.M.D.I.)
| | - Guidalberto Manfioletti
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (L.S.); (A.M.D.I.)
| |
Collapse
|
3
|
Pantier R, Brown M, Han S, Paton K, Meek S, Montavon T, Shukeir N, McHugh T, Kelly DA, Hochepied T, Libert C, Jenuwein T, Burdon T, Bird A. MeCP2 binds to methylated DNA independently of phase separation and heterochromatin organisation. Nat Commun 2024; 15:3880. [PMID: 38719804 PMCID: PMC11079052 DOI: 10.1038/s41467-024-47395-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 03/29/2024] [Indexed: 05/12/2024] Open
Abstract
Correlative evidence has suggested that the methyl-CpG-binding protein MeCP2 contributes to the formation of heterochromatin condensates via liquid-liquid phase separation. This interpretation has been reinforced by the observation that heterochromatin, DNA methylation and MeCP2 co-localise within prominent foci in mouse cells. The findings presented here revise this view. MeCP2 localisation is independent of heterochromatin as MeCP2 foci persist even when heterochromatin organisation is disrupted. Additionally, MeCP2 foci fail to show hallmarks of phase separation in live cells. Importantly, we find that mouse cellular models are highly atypical as MeCP2 distribution is diffuse in most mammalian species, including humans. Notably, MeCP2 foci are absent in Mus spretus which is a mouse subspecies lacking methylated satellite DNA repeats. We conclude that MeCP2 has no intrinsic tendency to form condensates and its localisation is independent of heterochromatin. Instead, the distribution of MeCP2 in the nucleus is primarily determined by global DNA methylation patterns.
Collapse
Affiliation(s)
- Raphaël Pantier
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Megan Brown
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Sicheng Han
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Katie Paton
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Stephen Meek
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Thomas Montavon
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Nicholas Shukeir
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Toni McHugh
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - David A Kelly
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK
| | - Tino Hochepied
- Center for Inflammation Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Claude Libert
- Center for Inflammation Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Thomas Jenuwein
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Tom Burdon
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Adrian Bird
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, The King's Buildings, Edinburgh, EH9 3BF, UK.
| |
Collapse
|
4
|
Bijlani S, Pang KM, Bugga LV, Rangasamy S, Narayanan V, Chatterjee S. Nuclease-free precise genome editing corrects MECP2 mutations associated with Rett syndrome. Front Genome Ed 2024; 6:1346781. [PMID: 38495533 PMCID: PMC10940404 DOI: 10.3389/fgeed.2024.1346781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/12/2024] [Indexed: 03/19/2024] Open
Abstract
Rett syndrome is an acquired progressive neurodevelopmental disorder caused by de novo mutations in the X-linked MECP2 gene which encodes a pleiotropic protein that functions as a global transcriptional regulator and a chromatin modifier. Rett syndrome predominantly affects heterozygous females while affected male hemizygotes rarely survive. Gene therapy of Rett syndrome has proven challenging due to a requirement for stringent regulation of expression with either over- or under-expression being toxic. Ectopic expression of MECP2 in conjunction with regulatory miRNA target sequences has achieved some success, but the durability of this approach remains unknown. Here we evaluated a nuclease-free homologous recombination (HR)-based genome editing strategy to correct mutations in the MECP2 gene. The stem cell-derived AAVHSCs have previously been shown to mediate seamless and precise HR-based genome editing. We tested the ability of HR-based genome editing to correct pathogenic mutations in Exons 3 and 4 of the MECP2 gene and restore the wild type sequence while preserving all native genomic regulatory elements associated with MECP2 expression, thus potentially addressing a significant issue in gene therapy for Rett syndrome. Moreover, since the mutations are edited directly at the level of the genome, the corrections are expected to be durable with progeny cells inheriting the edited gene. The AAVHSC MECP2 editing vector was designed to be fully homologous to the target MECP2 region and to insert a promoterless Venus reporter at the end of Exon 4. Evaluation of AAVHSC editing in a panel of Rett cell lines bearing mutations in Exons 3 and 4 demonstrated successful correction and rescue of expression of the edited MECP2 gene. Sequence analysis of edited Rett cells revealed successful and accurate correction of mutations in both Exons 3 and 4 and permitted mapping of HR crossover events. Successful correction was observed only when the mutations were flanked at both the 5' and 3' ends by crossover events, but not when both crossovers occurred either exclusively upstream or downstream of the mutation. Importantly, we concluded that pathogenic mutations were successfully corrected in every Rett line analyzed, demonstrating the therapeutic potential of HR-based genome editing.
Collapse
Affiliation(s)
- Swati Bijlani
- Department of Surgery, Beckman Research Institute of the City of Hope, Duarte, CA, United States
| | - Ka Ming Pang
- Department of Surgery, Beckman Research Institute of the City of Hope, Duarte, CA, United States
| | - Lakshmi V. Bugga
- Department of Surgery, Beckman Research Institute of the City of Hope, Duarte, CA, United States
| | - Sampath Rangasamy
- Center for Rare Childhood Disorders (C4RCD), Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ, United States
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders (C4RCD), Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ, United States
| | - Saswati Chatterjee
- Department of Surgery, Beckman Research Institute of the City of Hope, Duarte, CA, United States
| |
Collapse
|
5
|
Schmidt A, Zhang H, Schmitt S, Rausch C, Popp O, Chen J, Cmarko D, Butter F, Dittmar G, Lermyte F, Cardoso MC. The Proteomic Composition and Organization of Constitutive Heterochromatin in Mouse Tissues. Cells 2024; 13:139. [PMID: 38247831 PMCID: PMC10814525 DOI: 10.3390/cells13020139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/13/2023] [Accepted: 01/09/2024] [Indexed: 01/23/2024] Open
Abstract
Pericentric heterochromatin (PCH) forms spatio-temporarily distinct compartments and affects chromosome organization and stability. Albeit some of its components are known, an elucidation of its proteome and how it differs between tissues in vivo is lacking. Here, we find that PCH compartments are dynamically organized in a tissue-specific manner, possibly reflecting compositional differences. As the mouse brain and liver exhibit very different PCH architecture, we isolated native PCH fractions from these tissues, analyzed their protein compositions using quantitative mass spectrometry, and compared them to identify common and tissue-specific PCH proteins. In addition to heterochromatin-enriched proteins, the PCH proteome includes RNA/transcription and membrane-related proteins, which showed lower abundance than PCH-enriched proteins. Thus, we applied a cut-off of PCH-unspecific candidates based on their abundance and validated PCH-enriched proteins. Amongst the hits, MeCP2 was classified into brain PCH-enriched proteins, while linker histone H1 was not. We found that H1 and MeCP2 compete to bind to PCH and regulate PCH organization in opposite ways. Altogether, our workflow of unbiased PCH isolation, quantitative mass spectrometry, and validation-based analysis allowed the identification of proteins that are common and tissue-specifically enriched at PCH. Further investigation of selected hits revealed their opposing role in heterochromatin higher-order architecture in vivo.
Collapse
Affiliation(s)
- Annika Schmidt
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
| | - Hui Zhang
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
| | - Stephanie Schmitt
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
| | - Cathia Rausch
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
| | - Oliver Popp
- Proteomics Platform, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Jiaxuan Chen
- Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Dusan Cmarko
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 00 Prague, Czech Republic
| | - Falk Butter
- Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Gunnar Dittmar
- Proteomics Platform, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Frederik Lermyte
- Clemens-Schöpf Institute of Organic Chemistry and Biochemistry, Department of Chemistry, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - M. Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
| |
Collapse
|
6
|
Abstract
The eukaryotic nucleus displays a variety of membraneless compartments with distinct biomolecular composition and specific cellular activities. Emerging evidence indicates that protein-based liquid-liquid phase separation (LLPS) plays an essential role in the formation and dynamic regulation of heterochromatin compartmentalization. This feature is especially conspicuous at the pericentric heterochromatin domains. In this review, we will describe our understanding of heterochromatin organization and LLPS. In addition, we will highlight the increasing importance of multivalent weak homo- and heteromolecular interactions in LLPS-mediated heterochromatin compartmentalization in the complex environment inside living cells.
Collapse
Affiliation(s)
- Hui Zhang
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Weihua Qin
- Human Biology and Bioimaging, Faculty of Biology, Ludwig Maximilians University Munich, Planegg-Martinsried, Germany
| | - Hector Romero
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Heinrich Leonhardt
- Human Biology and Bioimaging, Faculty of Biology, Ludwig Maximilians University Munich, Planegg-Martinsried, Germany
| | - M. Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany,CONTACT M. Cristina Cardoso Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Schnittspahnstr. 10, 64287Darmstadt, Germany
| |
Collapse
|
7
|
Senapati S, Irshad IU, Sharma AK, Kumar H. Fundamental insights into the correlation between chromosome configuration and transcription. Phys Biol 2023; 20:051002. [PMID: 37467757 DOI: 10.1088/1478-3975/ace8e5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 07/19/2023] [Indexed: 07/21/2023]
Abstract
Eukaryotic chromosomes exhibit a hierarchical organization that spans a spectrum of length scales, ranging from sub-regions known as loops, which typically comprise hundreds of base pairs, to much larger chromosome territories that can encompass a few mega base pairs. Chromosome conformation capture experiments that involve high-throughput sequencing methods combined with microscopy techniques have enabled a new understanding of inter- and intra-chromosomal interactions with unprecedented details. This information also provides mechanistic insights on the relationship between genome architecture and gene expression. In this article, we review the recent findings on three-dimensional interactions among chromosomes at the compartment, topologically associating domain, and loop levels and the impact of these interactions on the transcription process. We also discuss current understanding of various biophysical processes involved in multi-layer structural organization of chromosomes. Then, we discuss the relationships between gene expression and genome structure from perturbative genome-wide association studies. Furthermore, for a better understanding of how chromosome architecture and function are linked, we emphasize the role of epigenetic modifications in the regulation of gene expression. Such an understanding of the relationship between genome architecture and gene expression can provide a new perspective on the range of potential future discoveries and therapeutic research.
Collapse
Affiliation(s)
- Swayamshree Senapati
- School of Basic Sciences, Indian Institute of Technology, Bhubaneswar, Argul, Odisha 752050, India
| | - Inayat Ullah Irshad
- Department of Physics, Indian Institute of Technology, Jammu, Jammu 181221, India
| | - Ajeet K Sharma
- Department of Physics, Indian Institute of Technology, Jammu, Jammu 181221, India
- Department of Biosciences and Bioengineering, Indian Institute of Technology Jammu, Jammu 181221, India
| | - Hemant Kumar
- School of Basic Sciences, Indian Institute of Technology, Bhubaneswar, Argul, Odisha 752050, India
| |
Collapse
|
8
|
Mok RSF, Zhang W, Sheikh TI, Pradeepan K, Fernandes IR, DeJong LC, Benigno G, Hildebrandt MR, Mufteev M, Rodrigues DC, Wei W, Piekna A, Liu J, Muotri AR, Vincent JB, Muller L, Martinez-Trujillo J, Salter MW, Ellis J. Wide spectrum of neuronal and network phenotypes in human stem cell-derived excitatory neurons with Rett syndrome-associated MECP2 mutations. Transl Psychiatry 2022; 12:450. [PMID: 36253345 PMCID: PMC9576700 DOI: 10.1038/s41398-022-02216-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/01/2022] [Accepted: 10/03/2022] [Indexed: 11/19/2022] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder primarily caused by heterozygous loss-of-function mutations in the X-linked gene MECP2 that is a global transcriptional regulator. Mutations in the methyl-CpG binding domain (MBD) of MECP2 disrupt its interaction with methylated DNA. Here, we investigate the effect of a novel MECP2 L124W missense mutation in the MBD of an atypical RTT patient with preserved speech in comparison to severe MECP2 null mutations. L124W protein had a limited ability to disrupt heterochromatic chromocenters due to decreased binding dynamics. We isolated two pairs of isogenic WT and L124W induced pluripotent stem cells. L124W induced excitatory neurons expressed stable protein, exhibited increased input resistance and decreased voltage-gated Na+ and K+ currents, and their neuronal dysmorphology was limited to decreased dendritic complexity. Three isogenic pairs of MECP2 null neurons had the expected more extreme morphological and electrophysiological phenotypes. We examined development and maturation of L124W and MECP2 null excitatory neural network activity using micro-electrode arrays. Relative to isogenic controls, L124W neurons had an increase in synchronous network burst frequency, in contrast to MECP2 null neurons that suffered a significant decrease in synchronous network burst frequency and a transient extension of network burst duration. A biologically motivated computational neural network model shows the observed changes in network dynamics are explained by changes in intrinsic Na+ and K+ currents in individual neurons. Our multilevel results demonstrate that RTT excitatory neurons show a wide spectrum of morphological, electrophysiological and circuitry phenotypes that are dependent on the severity of the MECP2 mutation.
Collapse
Grants
- R01 MH108528 NIMH NIH HHS
- MOP-133423 CIHR
- R01 MH109885 NIMH NIH HHS
- FDN-154336 CIHR
- R01 MH100175 NIMH NIH HHS
- Col Harland Sanders Rett Syndrome Research Fund at the University of Toronto (to J.E.), SFARI (Research grant #514918 to J.E. and J.M-T), CIHR (MOP-133423 to J.E. and M.W.S.; ERARE Team Grant ERT161303 to J.E.), CIHR foundation grant (FDN-154336 to M.W.S), Ontario Brain Institute (POND Network to J.E.), McLaughlin Centre Accelerator grant (to J.E.), John Evans Leadership Fund & Ontario Research Fund (to J.E), Canada Research Chair in Stem Cell Models of Childhood Disease (to J.E.), Beta Sigma Phi International Endowment Fund (to J.E.).
- BrainsCAN at Western University through the Canada First Research Excellence Fund (CFREF) (to GB, KP, LM, JMT). NSERC Postgraduate Scholarship–Doctoral (PGS-D) Scholarship to KP.
- Trainee support was provided by Restracomp (to LCD).
- National Institutes of Health (NIH) grants # R01MH108528, R01MH109885, and R01MH1000175 to ARM.
- Ontario Rett Syndrome Association to JBV.
- SFARI (Research grant #514918 to J.E. and J.M-T), BrainsCAN at Western University through the Canada First Research Excellence Fund (CFREF) (to GB, KP, LM, JMT)
- CIHR (MOP-133423 to J.E. and M.W.S.; CIHR foundation grant (FDN-154336 to M.W.S),
Collapse
Affiliation(s)
- Rebecca S F Mok
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Wenbo Zhang
- Neurosciences & Mental Health Program, The Hospital for Sick Children, Toronto, M5G 0A4, ON, Canada
| | - Taimoor I Sheikh
- Molecular Neuropsychiatry & Development (MiND) Lab, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, M5T 1R8, Canada
| | - Kartik Pradeepan
- Department of Physiology and Pharmacology, Department of Psychiatry, Neuroscience Graduate Program, Robarts Research and Brain and Mind Institutes, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 5B7, Canada
| | - Isabella R Fernandes
- University of California San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, Stem Cell Program, La Jolla, CA, 92037-0695, USA
| | - Leah C DeJong
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Gabriel Benigno
- Department of Applied Mathematics, Robarts Research Institute, Brain and Mind Institute, Western University, London, ON, N6A 5B7, Canada
| | - Matthew R Hildebrandt
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Marat Mufteev
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Deivid C Rodrigues
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Wei Wei
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Alina Piekna
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Jiajie Liu
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Alysson R Muotri
- University of California San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, Stem Cell Program, La Jolla, CA, 92037-0695, USA
- Department of Pediatrics/Rady Children's Hospital, Department of Cellular & Molecular Medicine, Center for Academic Research and Training in Anthropogeny, Archealization Center, Kavli Institute, University of California San Diego, La Jolla, CA, 92037, USA
| | - John B Vincent
- Molecular Neuropsychiatry & Development (MiND) Lab, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, M5T 1R8, Canada
| | - Lyle Muller
- Department of Applied Mathematics, Robarts Research Institute, Brain and Mind Institute, Western University, London, ON, N6A 5B7, Canada
| | - Julio Martinez-Trujillo
- Department of Physiology and Pharmacology, Department of Psychiatry, Neuroscience Graduate Program, Robarts Research and Brain and Mind Institutes, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 5B7, Canada
| | - Michael W Salter
- Neurosciences & Mental Health Program, The Hospital for Sick Children, Toronto, M5G 0A4, ON, Canada
- Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - James Ellis
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.
| |
Collapse
|
9
|
Schmidt A, Frei J, Poetsch A, Chittka A, Zhang H, Aßmann C, Lehmkuhl A, Bauer UM, Nuber UA, Cardoso MC. MeCP2 heterochromatin organization is modulated by arginine methylation and serine phosphorylation. Front Cell Dev Biol 2022; 10:941493. [PMID: 36172281 PMCID: PMC9510713 DOI: 10.3389/fcell.2022.941493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/19/2022] [Indexed: 11/23/2022] Open
Abstract
Rett syndrome is a human intellectual disability disorder that is associated with mutations in the X-linked MECP2 gene. The epigenetic reader MeCP2 binds to methylated cytosines on the DNA and regulates chromatin organization. We have shown previously that MECP2 Rett syndrome missense mutations are impaired in chromatin binding and heterochromatin reorganization. Here, we performed a proteomics analysis of post-translational modifications of MeCP2 isolated from adult mouse brain. We show that MeCP2 carries various post-translational modifications, among them phosphorylation on S80 and S421, which lead to minor changes in either heterochromatin binding kinetics or clustering. We found that MeCP2 is (di)methylated on several arginines and that this modification alters heterochromatin organization. Interestingly, we identified the Rett syndrome mutation site R106 as a dimethylation site. In addition, co-expression of protein arginine methyltransferases (PRMT)1 and PRMT6 lead to a decrease of heterochromatin clustering. Altogether, we identified and validated novel modifications of MeCP2 in the brain and show that these can modulate its ability to bind as well as reorganize heterochromatin, which may play a role in the pathology of Rett syndrome.
Collapse
Affiliation(s)
- Annika Schmidt
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Jana Frei
- Stem Cell and Developmental Biology, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Ansgar Poetsch
- Queen Mary School, Medical College, Nanchang University, Nanchang, China
- Plant Biochemistry, Ruhr University Bochum, Bochum, Germany
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Alexandra Chittka
- Division of Medicine, The Wolfson Institute for Biomedical Research, University College London, London, United Kingdom
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Hui Zhang
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Chris Aßmann
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, Marburg, Germany
| | - Anne Lehmkuhl
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Uta-Maria Bauer
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, Marburg, Germany
| | - Ulrike A. Nuber
- Stem Cell and Developmental Biology, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
- *Correspondence: Ulrike A. Nuber, ; M. Cristina Cardoso,
| | - M. Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
- *Correspondence: Ulrike A. Nuber, ; M. Cristina Cardoso,
| |
Collapse
|
10
|
Arroyo M, Hastert FD, Zhadan A, Schelter F, Zimbelmann S, Rausch C, Ludwig AK, Carell T, Cardoso MC. Isoform-specific and ubiquitination dependent recruitment of Tet1 to replicating heterochromatin modulates methylcytosine oxidation. Nat Commun 2022; 13:5173. [PMID: 36056023 PMCID: PMC9440122 DOI: 10.1038/s41467-022-32799-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 08/15/2022] [Indexed: 01/26/2023] Open
Abstract
Oxidation of the epigenetic DNA mark 5-methylcytosine by Tet dioxygenases is an established route to diversify the epigenetic information, modulate gene expression and overall cellular (patho-)physiology. Here, we demonstrate that Tet1 and its short isoform Tet1s exhibit distinct nuclear localization during DNA replication resulting in aberrant cytosine modification levels in human and mouse cells. We show that Tet1 is tethered away from heterochromatin via its zinc finger domain, which is missing in Tet1s allowing its targeting to these regions. We find that Tet1s interacts with and is ubiquitinated by CRL4(VprBP). The ubiquitinated Tet1s is then recognized by Uhrf1 and recruited to late replicating heterochromatin. This leads to spreading of 5-methylcytosine oxidation to heterochromatin regions, LINE 1 activation and chromatin decondensation. In summary, we elucidate a dual regulation mechanism of Tet1, contributing to the understanding of how epigenetic information can be diversified by spatio-temporal directed Tet1 catalytic activity.
Collapse
Affiliation(s)
- María Arroyo
- grid.6546.10000 0001 0940 1669Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany
| | - Florian D. Hastert
- grid.6546.10000 0001 0940 1669Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany ,grid.425396.f0000 0001 1019 0926Section AIDS and newly emerging pathogens, Paul Ehrlich Institute, Paul-Ehrlich-Str. 51-59, 63225 Langen, Germany
| | - Andreas Zhadan
- grid.6546.10000 0001 0940 1669Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany
| | - Florian Schelter
- grid.5252.00000 0004 1936 973XDepartment of Chemistry, Ludwig Maximilians University, Butenandstr. 5-13, 81377 Munich, Germany
| | - Susanne Zimbelmann
- grid.6546.10000 0001 0940 1669Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany
| | - Cathia Rausch
- grid.6546.10000 0001 0940 1669Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany ,grid.16008.3f0000 0001 2295 9843Present Address: Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6, avenue du Swing, L-4367 Belvaux, Luxembourg
| | - Anne K. Ludwig
- grid.6546.10000 0001 0940 1669Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany ,grid.5253.10000 0001 0328 4908Present Address: Department of Medicine, Hematology, Oncology and Rheumatology, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Thomas Carell
- grid.5252.00000 0004 1936 973XDepartment of Chemistry, Ludwig Maximilians University, Butenandstr. 5-13, 81377 Munich, Germany
| | - M. Cristina Cardoso
- grid.6546.10000 0001 0940 1669Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany
| |
Collapse
|
11
|
Zhang H, Romero H, Schmidt A, Gagova K, Qin W, Bertulat B, Lehmkuhl A, Milden M, Eck M, Meckel T, Leonhardt H, Cardoso MC. MeCP2-induced heterochromatin organization is driven by oligomerization-based liquid–liquid phase separation and restricted by DNA methylation. Nucleus 2022; 13:1-34. [PMID: 35156529 PMCID: PMC8855868 DOI: 10.1080/19491034.2021.2024691] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Hui Zhang
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Hector Romero
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Annika Schmidt
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Katalina Gagova
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Weihua Qin
- Faculty of Biology, Ludwig Maximilians University Munich, Munich, Germany
| | - Bianca Bertulat
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Anne Lehmkuhl
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Manuela Milden
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Malte Eck
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Tobias Meckel
- Department of Chemistry, Technical University of Darmstadt, Darmstadt, Germany
| | - Heinrich Leonhardt
- Faculty of Biology, Ludwig Maximilians University Munich, Munich, Germany
| | - M. Cristina Cardoso
- Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| |
Collapse
|
12
|
Abstract
In eukaryotic cells, protein and RNA factors involved in genome activities like transcription, RNA processing, DNA replication, and repair accumulate in self-organizing membraneless chromatin subcompartments. These structures contribute to efficiently conduct chromatin-mediated reactions and to establish specific cellular programs. However, the underlying mechanisms for their formation are only partly understood. Recent studies invoke liquid-liquid phase separation (LLPS) of proteins and RNAs in the establishment of chromatin activity patterns. At the same time, the folding of chromatin in the nucleus can drive genome partitioning into spatially distinct domains. Here, the interplay between chromatin organization, chromatin binding, and LLPS is discussed by comparing and contrasting three prototypical chromatin subcompartments: the nucleolus, clusters of active RNA polymerase II, and pericentric heterochromatin domains. It is discussed how the different ways of chromatin compartmentalization are linked to transcription regulation, the targeting of soluble factors to certain parts of the genome, and to disease-causing genetic aberrations.
Collapse
Affiliation(s)
- Karsten Rippe
- Division of Chromatin Networks, German Cancer Research Center (DKFZ) and Bioquant, 69120 Heidelberg, Germany
| |
Collapse
|
13
|
Fioriniello S, Csukonyi E, Marano D, Brancaccio A, Madonna M, Zarrillo C, Romano A, Marracino F, Matarazzo MR, D'Esposito M, Della Ragione F. MeCP2 and Major Satellite Forward RNA Cooperate for Pericentric Heterochromatin Organization. Stem Cell Reports 2021; 15:1317-1332. [PMID: 33296675 PMCID: PMC7724518 DOI: 10.1016/j.stemcr.2020.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 11/07/2020] [Accepted: 11/10/2020] [Indexed: 12/20/2022] Open
Abstract
Methyl-CpG binding protein 2 (MeCP2) has historically been linked to heterochromatin organization, and in mouse cells it accumulates at pericentric heterochromatin (PCH), closely following major satellite (MajSat) DNA distribution. However, little is known about the specific function of MeCP2 in these regions. We describe the first evidence of a role in neurons for MeCP2 and MajSat forward (MajSat-fw) RNA in reciprocal targeting to PCH through their physical interaction. Moreover, MeCP2 contributes to maintenance of PCH by promoting deposition of H3K9me3 and H4K20me3. We highlight that the MeCP2B isoform is required for correct higher-order PCH organization, and underline involvement of the methyl-binding and transcriptional repression domains. The T158 residue, which is commonly mutated in Rett patients, is directly involved in this process. Our findings support the hypothesis that MeCP2 and the MajSat-fw transcript are mutually dependent for PCH organization, and contribute to clarify MeCP2 function in the regulation of chromatin architecture.
Collapse
Affiliation(s)
- Salvatore Fioriniello
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', CNR, Naples 80131, Italy
| | - Eva Csukonyi
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', CNR, Naples 80131, Italy
| | - Domenico Marano
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', CNR, Naples 80131, Italy
| | - Arianna Brancaccio
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', CNR, Naples 80131, Italy
| | | | - Carmela Zarrillo
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', CNR, Naples 80131, Italy
| | | | | | - Maria R Matarazzo
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', CNR, Naples 80131, Italy
| | - Maurizio D'Esposito
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', CNR, Naples 80131, Italy
| | | |
Collapse
|
14
|
Anania C, Lupiáñez DG. Order and disorder: abnormal 3D chromatin organization in human disease. Brief Funct Genomics 2021; 19:128-138. [PMID: 32025693 PMCID: PMC7115703 DOI: 10.1093/bfgp/elz028] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 07/23/2019] [Accepted: 09/20/2019] [Indexed: 02/06/2023] Open
Abstract
A precise three-dimensional (3D) organization of chromatin is central to achieve the intricate transcriptional patterns that are required to form complex organisms. Growing evidence supports an important role of 3D chromatin architecture in development and delineates its alterations as prominent causes of disease. In this review, we discuss emerging concepts on the fundamental forces shaping genomes in space and on how their disruption can lead to pathogenic phenotypes. We describe the molecular mechanisms underlying a wide range of diseases, from the systemic effects of coding mutations on 3D architectural factors, to the more tissue-specific phenotypes resulting from genetic and epigenetic modifications at specific loci. Understanding the connection between the 3D organization of the genome and its underlying biological function will allow a better interpretation of human pathogenesis.
Collapse
Affiliation(s)
- Chiara Anania
- Epigenetics and Sex Development Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Darío G Lupiáñez
- Epigenetics and Sex Development Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Center for Molecular Medicine, Berlin, Germany
| |
Collapse
|
15
|
Transcriptomic and Epigenomic Landscape in Rett Syndrome. Biomolecules 2021; 11:biom11070967. [PMID: 34209228 PMCID: PMC8301932 DOI: 10.3390/biom11070967] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 12/13/2022] Open
Abstract
Rett syndrome (RTT) is an extremely invalidating, cureless, developmental disorder, and it is considered one of the leading causes of intellectual disability in female individuals. The vast majority of RTT cases are caused by de novo mutations in the X-linked Methyl-CpG binding protein 2 (MECP2) gene, which encodes a multifunctional reader of methylated DNA. MeCP2 is a master epigenetic modulator of gene expression, with a role in the organization of global chromatin architecture. Based on its interaction with multiple molecular partners and the diverse epigenetic scenario, MeCP2 triggers several downstream mechanisms, also influencing the epigenetic context, and thus leading to transcriptional activation or repression. In this frame, it is conceivable that defects in such a multifaceted factor as MeCP2 lead to large-scale alterations of the epigenome, ranging from an unbalanced deposition of epigenetic modifications to a transcriptional alteration of both protein-coding and non-coding genes, with critical consequences on multiple downstream biological processes. In this review, we provide an overview of the current knowledge concerning the transcriptomic and epigenomic alterations found in RTT patients and animal models.
Collapse
|
16
|
Sun J, Yang J, Miao X, Loh HH, Pei D, Zheng H. Proteins in DNA methylation and their role in neural stem cell proliferation and differentiation. CELL REGENERATION (LONDON, ENGLAND) 2021; 10:7. [PMID: 33649938 PMCID: PMC7921253 DOI: 10.1186/s13619-020-00070-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 11/25/2020] [Indexed: 01/03/2023]
Abstract
BACKGROUND Epigenetic modifications, namely non-coding RNAs, DNA methylation, and histone modifications such as methylation, phosphorylation, acetylation, ubiquitylation, and sumoylation play a significant role in brain development. DNA methyltransferases, methyl-CpG binding proteins, and ten-eleven translocation proteins facilitate the maintenance, interpretation, and removal of DNA methylation, respectively. Different forms of methylation, including 5-methylcytosine, 5-hydroxymethylcytosine, and other oxidized forms, have been detected by recently developed sequencing technologies. Emerging evidence suggests that the diversity of DNA methylation patterns in the brain plays a key role in fine-tuning and coordinating gene expression in the development, plasticity, and disorders of the mammalian central nervous system. Neural stem cells (NSCs), originating from the neuroepithelium, generate neurons and glial cells in the central nervous system and contribute to brain plasticity in the adult mammalian brain. MAIN BODY Here, we summarized recent research in proteins responsible for the establishment, maintenance, interpretation, and removal of DNA methylation and those involved in the regulation of the proliferation and differentiation of NSCs. In addition, we discussed the interactions of chemicals with epigenetic pathways to regulate NSCs as well as the connections between proteins involved in DNA methylation and human diseases. CONCLUSION Understanding the interplay between DNA methylation and NSCs in a broad biological context can facilitate the related studies and reduce potential misunderstanding.
Collapse
Affiliation(s)
- Jiaqi Sun
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China.
| | - Junzheng Yang
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China
| | - Xiaoli Miao
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China
| | - Horace H Loh
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China
| | - Duanqing Pei
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China.,CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou, 510530, China.,Institutes for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.,School of Life Science, Westlake University, Hangzhou, 310024, China
| | - Hui Zheng
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), #188 Kaiyuan Ave., Science City, Huangpu District, Guangzhou, 510700, China. .,CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. .,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou, 510530, China. .,Institutes for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
| |
Collapse
|
17
|
D'Mello SR. MECP2 and the Biology of MECP2 Duplication Syndrome. J Neurochem 2021; 159:29-60. [PMID: 33638179 DOI: 10.1111/jnc.15331] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/21/2021] [Accepted: 02/18/2021] [Indexed: 11/27/2022]
Abstract
MECP2 duplication syndrome (MDS), a rare X-linked genomic disorder affecting predominantly males, is caused by duplication of the chromosomal region containing the methyl CpG binding protein-2 (MECP2) gene, which encodes methyl-CpG-binding protein 2 (MECP2), a multi-functional protein required for proper brain development and maintenance of brain function during adulthood. Disease symptoms include severe motor and cognitive impairment, delayed or absent speech development, autistic features, seizures, ataxia, recurrent respiratory infections and shortened lifespan. The cellular and molecular mechanisms by which a relatively modest increase in MECP2 protein causes such severe disease symptoms are poorly understood and consequently there are no treatments available for this fatal disorder. This review summarizes what is known to date about the structure and complex regulation of MECP2 and its many functions in the developing and adult brain. Additionally, recent experimental findings on the cellular and molecular underpinnings of MDS based on cell culture and mouse models of the disorder are reviewed. The emerging picture from these studies is that MDS is a neurodegenerative disorder in which neurons die in specific parts of the central nervous system, including the cortex, hippocampus, cerebellum and spinal cord. Neuronal death likely results from astrocytic dysfunction, including a breakdown of glutamate homeostatic mechanisms. The role of elevations in the expression of glial acidic fibrillary protein (GFAP) in astrocytes and the microtubule-associated protein, Tau, in neurons to the pathogenesis of MDS is discussed. Lastly, potential therapeutic strategies to potentially treat MDS are discussed.
Collapse
|
18
|
Good KV, Vincent JB, Ausió J. MeCP2: The Genetic Driver of Rett Syndrome Epigenetics. Front Genet 2021; 12:620859. [PMID: 33552148 PMCID: PMC7859524 DOI: 10.3389/fgene.2021.620859] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/05/2021] [Indexed: 12/24/2022] Open
Abstract
Mutations in methyl CpG binding protein 2 (MeCP2) are the major cause of Rett syndrome (RTT), a rare neurodevelopmental disorder with a notable period of developmental regression following apparently normal initial development. Such MeCP2 alterations often result in changes to DNA binding and chromatin clustering ability, and in the stability of this protein. Among other functions, MeCP2 binds to methylated genomic DNA, which represents an important epigenetic mark with broad physiological implications, including neuronal development. In this review, we will summarize the genetic foundations behind RTT, and the variable degrees of protein stability exhibited by MeCP2 and its mutated versions. Also, past and emerging relationships that MeCP2 has with mRNA splicing, miRNA processing, and other non-coding RNAs (ncRNA) will be explored, and we suggest that these molecules could be missing links in understanding the epigenetic consequences incurred from genetic ablation of this important chromatin modifier. Importantly, although MeCP2 is highly expressed in the brain, where it has been most extensively studied, the role of this protein and its alterations in other tissues cannot be ignored and will also be discussed. Finally, the additional complexity to RTT pathology introduced by structural and functional implications of the two MeCP2 isoforms (MeCP2-E1 and MeCP2-E2) will be described. Epigenetic therapeutics are gaining clinical popularity, yet treatment for Rett syndrome is more complicated than would be anticipated for a purely epigenetic disorder, which should be taken into account in future clinical contexts.
Collapse
Affiliation(s)
- Katrina V. Good
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - John B. Vincent
- Molecular Neuropsychiatry & Development (MiND) Lab, Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| |
Collapse
|
19
|
Epigenetic Factors That Control Pericentric Heterochromatin Organization in Mammals. Genes (Basel) 2020; 11:genes11060595. [PMID: 32481609 PMCID: PMC7349813 DOI: 10.3390/genes11060595] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/17/2020] [Accepted: 05/25/2020] [Indexed: 12/11/2022] Open
Abstract
Pericentric heterochromatin (PCH) is a particular form of constitutive heterochromatin that is localized to both sides of centromeres and that forms silent compartments enriched in repressive marks. These genomic regions contain species-specific repetitive satellite DNA that differs in terms of nucleotide sequences and repeat lengths. In spite of this sequence diversity, PCH is involved in many biological phenomena that are conserved among species, including centromere function, the preservation of genome integrity, the suppression of spurious recombination during meiosis, and the organization of genomic silent compartments in the nucleus. PCH organization and maintenance of its repressive state is tightly regulated by a plethora of factors, including enzymes (e.g., DNA methyltransferases, histone deacetylases, and histone methyltransferases), DNA and histone methylation binding factors (e.g., MECP2 and HP1), chromatin remodeling proteins (e.g., ATRX and DAXX), and non-coding RNAs. This evidence helps us to understand how PCH organization is crucial for genome integrity. It then follows that alterations to the molecular signature of PCH might contribute to the onset of many genetic pathologies and to cancer progression. Here, we describe the most recent updates on the molecular mechanisms known to underlie PCH organization and function.
Collapse
|
20
|
MeCP2 and Chromatin Compartmentalization. Cells 2020; 9:cells9040878. [PMID: 32260176 PMCID: PMC7226738 DOI: 10.3390/cells9040878] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/27/2020] [Accepted: 04/01/2020] [Indexed: 12/24/2022] Open
Abstract
Methyl-CpG binding protein 2 (MeCP2) is a multifunctional epigenetic reader playing a role in transcriptional regulation and chromatin structure, which was linked to Rett syndrome in humans. Here, we focus on its isoforms and functional domains, interactions, modifications and mutations found in Rett patients. Finally, we address how these properties regulate and mediate the ability of MeCP2 to orchestrate chromatin compartmentalization and higher order genome architecture.
Collapse
|
21
|
Tillotson R, Bird A. The Molecular Basis of MeCP2 Function in the Brain. J Mol Biol 2020; 432:1602-1623. [PMID: 31629770 DOI: 10.1016/j.jmb.2019.10.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/14/2022]
Abstract
MeCP2 is a reader of the DNA methylome that occupies a large proportion of the genome due to its high abundance and the frequency of its target sites. It has been the subject of extensive study because of its link with 'MECP2-related disorders', of which Rett syndrome is the most prevalent. This review integrates evidence from patient mutation data with results of experimental studies using mouse models, cell lines and in vitro systems to critically evaluate our understanding of MeCP2 protein function. Recent evidence challenges the idea that MeCP2 is a multifunctional hub that integrates diverse processes to underpin neuronal function, suggesting instead that its primary role is to recruit the NCoR1/2 co-repressor complex to methylated sites in the genome, leading to dampening of gene expression.
Collapse
Affiliation(s)
- Rebekah Tillotson
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada; Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK.
| |
Collapse
|
22
|
Rett syndrome-causing mutations compromise MeCP2-mediated liquid-liquid phase separation of chromatin. Cell Res 2020; 30:393-407. [PMID: 32111972 DOI: 10.1038/s41422-020-0288-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/05/2020] [Indexed: 01/09/2023] Open
Abstract
Rett syndrome (RTT), a severe postnatal neurodevelopmental disorder, is caused by mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MeCP2). MeCP2 is a chromatin organizer regulating gene expression. RTT-causing mutations have been shown to affect this function. However, the mechanism by which MeCP2 organizes chromatin is unclear. In this study, we found that MeCP2 can induce compaction and liquid-liquid phase separation of nucleosomal arrays in vitro, and DNA methylation further enhances formation of chromatin condensates by MeCP2. Interestingly, RTT-causing mutations compromise MeCP2-mediated chromatin phase separation, while benign variants have little effect on this process. Moreover, MeCP2 competes with linker histone H1 to form mutually exclusive chromatin condensates in vitro and distinct heterochromatin foci in vivo. RTT-causing mutations reduce or even abolish the ability of MeCP2 to compete with histone H1 and to form chromatin condensates. Together, our results identify a novel mechanism by which phase separation underlies MeCP2-mediated heterochromatin formation and reveal the potential link between this process and the pathology of RTT.
Collapse
|
23
|
Maternal Experience-Dependent Cortical Plasticity in Mice Is Circuit- and Stimulus-Specific and Requires MECP2. J Neurosci 2020; 40:1514-1526. [PMID: 31911459 DOI: 10.1523/jneurosci.1964-19.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/12/2019] [Accepted: 12/20/2019] [Indexed: 01/26/2023] Open
Abstract
The neurodevelopmental disorder Rett syndrome is caused by mutations in the gene Mecp2 Misexpression of the protein MECP2 is thought to contribute to neuropathology by causing dysregulation of plasticity. Female heterozygous Mecp2 mutants (Mecp2het ) failed to acquire a learned maternal retrieval behavior when exposed to pups, an effect linked to disruption of parvalbumin-expressing inhibitory interneurons (PV) in the auditory cortex. Nevertheless, how dysregulated PV networks affect the neural activity dynamics that underlie auditory cortical plasticity during early maternal experience is unknown. Here we show that maternal experience in WT adult female mice (WT) triggers suppression of PV auditory responses. We also observe concomitant disinhibition of auditory responses in deep-layer pyramidal neurons that is selective for behaviorally relevant pup vocalizations. These neurons further exhibit sharpened tuning for pup vocalizations following maternal experience. All of these neuronal changes are abolished in Mecp2het , suggesting that they are an essential component of maternal learning. This is further supported by our finding that genetic manipulation of GABAergic networks that restores accurate retrieval behavior in Mecp2het also restores maternal experience-dependent plasticity of PV. Our data are consistent with a growing body of evidence that cortical networks are particularly vulnerable to mutations of Mecp2 in PV neurons. Moreover, our work links, for the first time, impaired in vivo cortical plasticity in awake Mecp2 mutant animals to a natural, ethologically relevant behavior.SIGNIFICANCE STATEMENT Rett syndrome is a genetic disorder that includes language communication problems. Nearly all Rett syndrome is caused by mutations in the gene that produces the protein MECP2, which is important for changes in brain connectivity believed to underlie learning. We previously showed that female Mecp2 mutants fail to learn a simple maternal care behavior performed in response to their pups' distress cries. This impairment appeared to critically involve inhibitory neurons in the auditory cortex called parvalbumin neurons. Here we record from these neurons before and after maternal experience, and we show that they adapt their response to pup calls during maternal learning in nonmutants, but not in mutants. This adaptation is partially restored by a manipulation that improves learning.
Collapse
|
24
|
Piccolo FM, Liu Z, Dong P, Hsu CL, Stoyanova EI, Rao A, Tjian R, Heintz N. MeCP2 nuclear dynamics in live neurons results from low and high affinity chromatin interactions. eLife 2019; 8:51449. [PMID: 31868585 PMCID: PMC6957317 DOI: 10.7554/elife.51449] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/22/2019] [Indexed: 01/08/2023] Open
Abstract
Methyl-CpG-binding-Protein 2 (MeCP2) is an abundant nuclear protein highly enriched in neurons. Here we report live-cell single-molecule imaging studies of the kinetic features of mouse MeCP2 at high spatial-temporal resolution. MeCP2 displays dynamic features that are distinct from both highly mobile transcription factors and immobile histones. Stable binding of MeCP2 in living neurons requires its methyl-binding domain and is sensitive to DNA modification levels. Diffusion of unbound MeCP2 is strongly constrained by weak, transient interactions mediated primarily by its AT-hook domains, and varies with the level of chromatin compaction and cell type. These findings extend previous studies of the role of the MeCP2 MBD in high affinity DNA binding to living neurons, and identify a new role for its AT-hooks domains as critical determinants of its kinetic behavior. They suggest that limited nuclear diffusion of MeCP2 in live neurons contributes to its local impact on chromatin structure and gene expression.
Collapse
Affiliation(s)
- Francesco M Piccolo
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Zhe Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Peng Dong
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Ching-Lung Hsu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Elitsa I Stoyanova
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Anjana Rao
- La Jolla Institute for Allergy and Immunology, La Jolla, United States
| | - Robert Tjian
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, CIRM Center of Excellence, University of California, Howard Hughes Medical Institute, Berkeley, United States
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| |
Collapse
|
25
|
DNA Modification Readers and Writers and Their Interplay. J Mol Biol 2019:S0022-2836(19)30718-1. [PMID: 31866298 DOI: 10.1016/j.jmb.2019.12.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 11/28/2019] [Accepted: 12/05/2019] [Indexed: 12/15/2022]
Abstract
Genomic DNA is modified in a postreplicative manner and several modifications, the enzymes responsible for their deposition as well as proteins that read these modifications, have been described. Here, we focus on the impact of DNA modifications on the DNA helix and review the writers and readers of cytosine modifications and how they interplay to shape genome composition, stability, and function.
Collapse
|
26
|
Gulmez Karaca K, Brito DV, Oliveira AM. MeCP2: A Critical Regulator of Chromatin in Neurodevelopment and Adult Brain Function. Int J Mol Sci 2019; 20:ijms20184577. [PMID: 31527487 PMCID: PMC6769791 DOI: 10.3390/ijms20184577] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/11/2019] [Accepted: 09/12/2019] [Indexed: 01/08/2023] Open
Abstract
Methyl CpG binding protein 2 (MeCP2) was first identified as a nuclear protein with a transcriptional repressor role that recognizes DNA methylation marks. MeCP2 has a well-established function in neurodevelopment, as evidenced by the severe neurological impairments characteristic of the Rett syndrome (RTT) pathology and the MeCP2 duplication syndrome (MDS), caused by loss or gain of MeCP2 function, respectively. Research aimed at the underlying pathophysiological mechanisms of RTT and MDS has significantly advanced our understanding of MeCP2 functions in the nervous system. It has revealed, however, that MeCP2 has more varied and complex roles than previously thought. Here we review recent insights into the functions of MeCP2 in neurodevelopment and the less explored requirement for MeCP2 in adult brain function. We focus on the emerging view that MeCP2 is a global chromatin organizer. Finally, we discuss how the individual functions of MeCP2 in neurodevelopment and adulthood are linked to its role as a chromatin regulator.
Collapse
Affiliation(s)
- Kubra Gulmez Karaca
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany; (K.G.K.)
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 EN Nijmegen, The Netherlands
| | - David V.C. Brito
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany; (K.G.K.)
| | - Ana M.M. Oliveira
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany; (K.G.K.)
- Correspondence: ; Tel.: +49-(0)6221-5416510
| |
Collapse
|
27
|
Choi MH, Palanichamy Kala M, Ow JR, Rao VK, Suriyamurthy S, Taneja R. GLP inhibits heterochromatin clustering and myogenic differentiation by repressing MeCP2. J Mol Cell Biol 2019; 10:161-174. [PMID: 28992061 DOI: 10.1093/jmcb/mjx038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 08/17/2017] [Indexed: 01/07/2023] Open
Abstract
Myogenic differentiation is accompanied by alterations in the chromatin states, which permit or restrict the transcriptional machinery and thus impact distinctive gene expression profiles. The mechanisms by which higher-order chromatin remodeling is associated with gene activation and silencing during differentiation is not fully understood. In this study, we provide evidence that the euchromatic lysine methyltransferase GLP regulates heterochromatin organization and myogenic differentiation. Interestingly, GLP represses expression of the methyl-binding protein MeCP2 that induces heterochromatin clustering during differentiation. Consequently, MeCP2 and HP1γ localization at major satellites are altered upon modulation of GLP expression. In GLP knockdown cells, depletion of MeCP2 restored both chromatin organization and myogenic differentiation. These results identify a novel regulatory axis between a histone methylation writer and DNA methylation reader, which is important for heterochromatin organization during differentiation.
Collapse
Affiliation(s)
- Min Hee Choi
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 117456, Singapore
| | - Monica Palanichamy Kala
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
| | - Jin Rong Ow
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 117456, Singapore
| | - Vinay Kumar Rao
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
| | - Sudha Suriyamurthy
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
| | - Reshma Taneja
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 117456, Singapore
| |
Collapse
|
28
|
Franklin D. P152R Mutation Within MeCP2 Can Cause Loss of DNA-Binding Selectivity. Interdiscip Sci 2019; 11:10-20. [PMID: 30673959 DOI: 10.1007/s12539-019-00316-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 01/04/2019] [Accepted: 01/09/2019] [Indexed: 11/29/2022]
Abstract
MeCP2 is a protein highly expressed in the brain that participates in the genetic expression and RNA splicing regulation. MeCP2 binds preferably to methylated DNA and other nuclear corepressors to alter chromatin. MECP2 gene mutations can cause rett syndrome (RTT), a severe neurological disorder that affects around one in ten thousand girls. In this paper, Molecular Dynamics (MD) simulations were performed to scrutinize how the MeCP2 P152R mutation influences the protein binding to DNA. Also, the Umbrella Sampling technique was used to obtain the potential mean forces (PMFs) of both wild-type and mutated MeCP2 Methyl-CpG-binding domain (MBD) binding to both non-methylated and methylated DNA. P152R is a common missense mutation in MBD associated with RTT; however, there are no studies that explain how it causes protein dysfunction. The results from this study hypothesize that P152R mutation leads to MBD binding more strongly to DNA, while selectively decreasing binding affinity to methylated DNA. These provide an explanation for previous not conclusive experimental results regarding the mechanism of how this mutation affects the binding of the protein to DNA, and subsequently its effects on RTT. Furthermore, the results of this research-in-progress can be used as the basis for further investigations into the molecular basis of RTT and to potentially reveal a target for therapy in the future.
Collapse
Affiliation(s)
- Dino Franklin
- Faculty of Computing, Federal University of Uberlandia, Uberlândia, Brazil.
| |
Collapse
|
29
|
Gandaglia A, Brivio E, Carli S, Palmieri M, Bedogni F, Stefanelli G, Bergo A, Leva B, Cattaneo C, Pizzamiglio L, Cicerone M, Bianchi V, Kilstrup-Nielsen C, D’Annessa I, Di Marino D, D’Adamo P, Antonucci F, Frasca A, Landsberger N. A Novel Mecp2Y120D Knock-in Model Displays Similar Behavioral Traits But Distinct Molecular Features Compared to the Mecp2-Null Mouse Implying Precision Medicine for the Treatment of Rett Syndrome. Mol Neurobiol 2018; 56:4838-4854. [DOI: 10.1007/s12035-018-1412-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 10/24/2018] [Indexed: 10/27/2022]
|
30
|
Sheikh TI, de Paz AM, Akhtar S, Ausió J, Vincent JB. MeCP2_E1 N-terminal modifications affect its degradation rate and are disrupted by the Ala2Val Rett mutation. Hum Mol Genet 2018; 26:4132-4141. [PMID: 28973632 DOI: 10.1093/hmg/ddx300] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 07/24/2017] [Indexed: 11/14/2022] Open
Abstract
Methyl CpG-binding protein 2 (MeCP2), the mutated protein in Rett syndrome (RTT), is a crucial chromatin-modifying and gene-regulatory protein that has two main isoforms (MeCP2_E1 and MeCP2_ E2) due to the alternative splicing and switching between translation start codons in exons one and two. Functionally, these two isoforms appear to be virtually identical; however, evidence suggests that only MeCP2_E1 is relevant to RTT, including a single RTT missense mutation in exon 1, Ala2Val. Here, we show that N-terminal co- and post-translational modifications differ for MeCP2_E1 and MeCP2_E1-Ala2Val, which result in different protein degradation rates in vitro. We report complete N-methionine excision (NME) for MeCP2_E1 and evidence of excision of multiple alanine residues from the N-terminal polyalanine stretch. For MeCP2_E1-Ala2Val, we observed only partial NME and N-acetylation (NA) of either methionine or valine. The localization of MeCP2_E1 and co-localization with chromatin appear to be unaffected by the Ala2Val mutation. However, a higher proteasomal degradation rate was observed for MeCP2_E1-Ala2Val compared with that for wild type MeCP2_E1. Thus, the etiopathology of Ala2Val is likely due to a reduced bio-availability of MeCP2 because of the faster degradation rate of the unmodified defective protein. Our data on the effects of the Ala2Val mutation on N-terminal modifications of MeCP2 may be applicable to Ala2Val mutations in other disease genes for which no etiopathological mechanism has been established.
Collapse
Affiliation(s)
- Taimoor I Sheikh
- Molecular Neuropsychiatry & Development (MiND) Lab, Brain Science Division, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A8, Canada
| | | | - Shamim Akhtar
- University of Engineering and Technology Taxila, Taxila, Punjab 47080, Pakistan
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, BC V8P 5C2, Canada
| | - John B Vincent
- Molecular Neuropsychiatry & Development (MiND) Lab, Brain Science Division, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
| |
Collapse
|
31
|
Sheikh TI, Harripaul R, Ayub M, Vincent JB. MeCP2 AT-Hook1 mutations in patients with intellectual disability and/or schizophrenia disrupt DNA binding and chromatin compaction in vitro. Hum Mutat 2018; 39:717-728. [DOI: 10.1002/humu.23409] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/10/2018] [Accepted: 02/07/2018] [Indexed: 01/29/2023]
Affiliation(s)
- Taimoor I. Sheikh
- Molecular Neuropsychiatry & Development (MiND) Lab; Campbell Family Mental Health Research Institute; Centre for Addiction and Mental Health; Toronto Ontario Canada
- Institute of Medical Science; University of Toronto; Toronto Ontario Canada
| | - Ricardo Harripaul
- Molecular Neuropsychiatry & Development (MiND) Lab; Campbell Family Mental Health Research Institute; Centre for Addiction and Mental Health; Toronto Ontario Canada
- Institute of Medical Science; University of Toronto; Toronto Ontario Canada
| | - Muhammad Ayub
- Lahore Institute of Research & Development; Lahore Pakistan
- Department of Psychiatry; Queen's University; Kingston Ontario Canada
| | - John B. Vincent
- Molecular Neuropsychiatry & Development (MiND) Lab; Campbell Family Mental Health Research Institute; Centre for Addiction and Mental Health; Toronto Ontario Canada
- Institute of Medical Science; University of Toronto; Toronto Ontario Canada
- Department of Psychiatry; University of Toronto; Toronto Ontario Canada
| |
Collapse
|
32
|
D'Annessa I, Gandaglia A, Brivio E, Stefanelli G, Frasca A, Landsberger N, Di Marino D. Tyr120Asp mutation alters domain flexibility and dynamics of MeCP2 DNA binding domain leading to impaired DNA interaction: Atomistic characterization of a Rett syndrome causing mutation. Biochim Biophys Acta Gen Subj 2018; 1862:1180-1189. [PMID: 29428602 DOI: 10.1016/j.bbagen.2018.02.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/30/2018] [Accepted: 02/06/2018] [Indexed: 11/28/2022]
Abstract
Mutations in the X-linked MECP2 gene represent the main origin of Rett syndrome, causing a profound intellectual disability in females. MeCP2 is an epigenetic transcriptional regulator containing two main functional domains: a methyl-CpG binding domain (MBD) and a transcription repression domain (TRD). Over 600 pathogenic mutations were reported to affect the whole protein; almost half of missense mutations affect the MBD. Understanding the impact of these mutations on the MBD structure and interaction with DNA will foster the comprehension of their pathogenicity and possibly genotype/phenotype correlation studies. Herein, we use molecular dynamics simulations to obtain a detailed view of the dynamics of WT and mutated MBD in the presence and absence of DNA. The pathogenic mutation Y120D is used as paradigm for our studies. Further, since the Y120 residue was previously found to be a phosphorylation site, we characterize the dynamic profile of the MBD also in the presence of Y120 phosphorylation (pY120). We found that addition of a phosphate group to Y120 or mutation in aspartic acid affect domain mobility that samples an alternative conformational space with respect to the WT, leading to impaired ability to interact with DNA. Experimental assays showing a significant reduction in the binding affinity between the mutated MBD and the DNA confirmed our predictions.
Collapse
Affiliation(s)
- Ilda D'Annessa
- Istituto di Chimica del Riconoscimento Molecolare, CNR, Milan, Italy
| | - Anna Gandaglia
- San Raffaele Rett Research Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Elena Brivio
- San Raffaele Rett Research Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Gilda Stefanelli
- San Raffaele Rett Research Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Angelisa Frasca
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Nicoletta Landsberger
- San Raffaele Rett Research Unit, San Raffaele Scientific Institute, Milan, Italy; Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy.
| | - Daniele Di Marino
- Department of Informatics, Institute of Computational Science, Università della Svizzera Italiana, Lugano, Switzerland.
| |
Collapse
|
33
|
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
|
34
|
Fujita Y, Yamashita T. Spatial organization of genome architecture in neuronal development and disease. Neurochem Int 2017; 119:49-56. [PMID: 28757389 DOI: 10.1016/j.neuint.2017.06.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 06/19/2017] [Accepted: 06/26/2017] [Indexed: 01/19/2023]
Abstract
Although mammalian genomes encode genetic information in their linear sequences, their fundamental function with regard to gene expression depends on the higher-order structure of chromosomes. Current techniques for the evaluation of chromosomal structure have revealed that genomes are arranged at several hierarchical levels in three-dimensional space. The spatial organization of genomes involves the formation of chromatin loops that bypass a wide range of genomic distances, providing a connection between enhancers and chromosomal domains. Furthermore, they form chromatin domains that are arranged into chromosome territories in the three-dimensional space of the cell nucleus. Recent studies have shown that the spatial organization of the genome is essential for normal brain development and function. Activity-dependent alterations in the spatial organization of the genome can regulate transcriptional activity related to neuronal plasticity. Disruptions in the higher-order chromatin architecture have been implicated in neuropsychiatric disorders, such as cognitive dysfunction and anxiety. Here, we discuss the growing interest in the role of genome organization in brain development and neurological disorders.
Collapse
Affiliation(s)
- Yuki Fujita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; WPI Immunology Frontier Research Center, Osaka University, Suita, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; WPI Immunology Frontier Research Center, Osaka University, Suita, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
| |
Collapse
|
35
|
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
|
36
|
Abstract
Monoallelic expression not due to cis-regulatory sequence polymorphism poses an intriguing problem in epigenetics because it requires the unequal treatment of two segments of DNA that are present in the same nucleus and that can indeed have absolutely identical sequences. Here, I focus on a few recent developments in the field of monoallelic expression that are of particular interest and raise interesting questions for future work. One development is regarding analyses of imprinted genes, in which recent work suggests the possibility that intriguing networks of imprinted genes exist and are important for genetic and physiological studies. Another issue that has been raised in recent years by a number of publications is the question of how skewed allelic expression should be for it to be designated as monoallelic expression and, further, what methods are appropriate or inappropriate for analyzing genomic data to examine allele-specific expression. Perhaps the most exciting recent development in mammalian monoallelic expression is a clever and carefully executed analysis of genetic diversity of autosomal genes subject to random monoallelic expression (RMAE), which provides compelling evidence for distinct evolutionary forces acting on random monoallelically expressed genes.
Collapse
Affiliation(s)
- Andrew Chess
- Department of Genetics and Genomic Sciences, Department of Developmental and Regenerative Biology, Fishberg Department of Neuroscience, and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029-6574;
| |
Collapse
|
37
|
From Function to Phenotype: Impaired DNA Binding and Clustering Correlates with Clinical Severity in Males with Missense Mutations in MECP2. Sci Rep 2016; 6:38590. [PMID: 27929079 PMCID: PMC5144150 DOI: 10.1038/srep38590] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/11/2016] [Indexed: 11/25/2022] Open
Abstract
Mutations in the MECP2 gene cause Rett syndrome (RTT). MeCP2 binds to chromocentric DNA through its methyl CpG-binding domain (MBD) to regulate gene expression. In heterozygous females the variable phenotypic severity is modulated by non-random X-inactivation, thus making genotype-phenotype comparisons unreliable. However, genotype-phenotype correlations in males with hemizygousMECP2 mutations can provide more accurate insights in to the true biological effect of specific mutations. Here, we compared chromatin organization and binding dynamics for twelve MeCP2 missense mutations (including two novel and the five most common MBD missense RTT mutations) and identifiedacorrelation with phenotype in hemizygous males. We observed impaired interaction of MeCP2-DNA for mutations around the MBD-DNA binding interface, and defective chromatin clustering for distal MBD mutations. Furthermore, binding and mobility dynamics show a gradient of impairment depending on the amino acid properties and tertiary structure within the MBD. Interestingly, a wide range of phenotypic/clinical severity, ranging from neonatal encephalopathy to mild psychiatric abnormalities were observed and all are consistent with our functional/molecular results. Overall, clinical severity showed a direct correlation with the functional impairment of MeCP2. These mechanistic and phenotypic correlations of MeCP2 mutations will enable improved and individualized diagnostics, and may lead to personalized therapeutic interventions.
Collapse
|
38
|
Medrano-Fernández A, Barco A. Nuclear organization and 3D chromatin architecture in cognition and neuropsychiatric disorders. Mol Brain 2016; 9:83. [PMID: 27595843 PMCID: PMC5011999 DOI: 10.1186/s13041-016-0263-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 08/06/2016] [Indexed: 01/08/2023] Open
Abstract
The current view of neuroplasticity depicts the changes in the strength and number of synaptic connections as the main physical substrate for behavioral adaptation to new experiences in a changing environment. Although transcriptional regulation is known to play a role in these synaptic changes, the specific contribution of activity-induced changes to both the structure of the nucleus and the organization of the genome remains insufficiently characterized. Increasing evidence indicates that plasticity-related genes may work in coordination and share architectural and transcriptional machinery within discrete genomic foci. Here we review the molecular and cellular mechanisms through which neuronal nuclei structurally adapt to stimuli and discuss how the perturbation of these mechanisms can trigger behavioral malfunction.
Collapse
Affiliation(s)
- Alejandro Medrano-Fernández
- Instituto de Neurociencias (Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas), Av. Santiago Ramón y Cajal s/n. Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Angel Barco
- Instituto de Neurociencias (Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas), Av. Santiago Ramón y Cajal s/n. Sant Joan d'Alacant, 03550, Alicante, Spain.
| |
Collapse
|
39
|
Khrapunov S, Tao Y, Cheng H, Padlan C, Harris R, Galanopoulou AS, Greally JM, Girvin ME, Brenowitz M. MeCP2 Binding Cooperativity Inhibits DNA Modification-Specific Recognition. Biochemistry 2016; 55:4275-85. [PMID: 27420643 DOI: 10.1021/acs.biochem.6b00451] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Methyl-CpG binding protein 2 (MeCP2) is a multifunctional protein that guides neuronal development through its binding to DNA, recognition of sites of methyl-CpG (mCpG) DNA modification, and interaction with other regulatory proteins. Our study explores the relationship between mCpG and hydroxymethyl-CpG (hmCpG) recognition mediated by its mCpG binding domain (MBD) and binding cooperativity mediated by its C-terminal polypeptide. Previous study of the isolated MBD of MeCP2 documented an unusual mechanism by which ion uptake is required for discrimination of mCpG and hmCpG from CpG. MeCP2 binding cooperativity suppresses discrimination of modified DNA and is highly sensitive to both the total ion concentration and the type of counterions. Higher than physiological total ion concentrations completely suppress MeCP2 binding cooperativity, indicating a dominant electrostatic component to the interaction. Substitution of SO4(2-) for Cl(-) at physiological total ion concentrations also suppresses MeCP2 binding cooperativity, This effect is of particular note as the intracellular Cl(-) concentration changes during neuronal development. A related effect is that the protein-stabilizing solutes, TMAO and glutamate, reduce MeCP2 (but not isolated MBD) binding affinity by 2 orders of magnitude without affecting the apparent binding cooperativity. These observations suggest that polypeptide flexibility facilitates DNA binding by MeCP2. Consistent with this view, nuclear magnetic resonance (NMR) analyses show that ions have discrete effects on the structure of MeCP2, both MBD and the C-terminal domains. Notably, anion substitution results in changes in the NMR chemical shifts of residues, including some whose mutation causes the autism spectrum disorder Rett syndrome. Binding cooperativity makes MeCP2 an effective competitor with histone H1 for accessible DNA sites. The relationship between MeCP2 binding specificity and cooperativity is discussed in the context of chromatin binding, neuronal function, and neuronal development.
Collapse
Affiliation(s)
- Sergei Khrapunov
- Department of Biochemistry, ‡Departments of Neurology and Neuroscience, and §Department of Genetics, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - Yisong Tao
- Department of Biochemistry, ‡Departments of Neurology and Neuroscience, and §Department of Genetics, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - Huiyong Cheng
- Department of Biochemistry, ‡Departments of Neurology and Neuroscience, and §Department of Genetics, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - Camille Padlan
- Department of Biochemistry, ‡Departments of Neurology and Neuroscience, and §Department of Genetics, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - Richard Harris
- Department of Biochemistry, ‡Departments of Neurology and Neuroscience, and §Department of Genetics, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - Aristea S Galanopoulou
- Department of Biochemistry, ‡Departments of Neurology and Neuroscience, and §Department of Genetics, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - John M Greally
- Department of Biochemistry, ‡Departments of Neurology and Neuroscience, and §Department of Genetics, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - Mark E Girvin
- Department of Biochemistry, ‡Departments of Neurology and Neuroscience, and §Department of Genetics, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - Michael Brenowitz
- Department of Biochemistry, ‡Departments of Neurology and Neuroscience, and §Department of Genetics, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| |
Collapse
|
40
|
Brain phosphorylation of MeCP2 at serine 164 is developmentally regulated and globally alters its chromatin association. Sci Rep 2016; 6:28295. [PMID: 27323888 PMCID: PMC4915018 DOI: 10.1038/srep28295] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/01/2016] [Indexed: 12/31/2022] Open
Abstract
MeCP2 is a transcriptional regulator whose functional alterations are responsible for several autism spectrum and mental disorders. Post-translational modifications (PTMs), and particularly differential phosphorylation, modulate MeCP2 function in response to diverse stimuli. Understanding the detailed role of MeCP2 phosphorylation is thus instrumental to ascertain how MeCP2 integrates the environmental signals and directs its adaptive transcriptional responses. The evolutionarily conserved serine 164 (S164) was found phosphorylated in rodent brain but its functional role has remained uncharacterized. We show here that phosphorylation of S164 in brain is dynamically regulated during neuronal maturation. S164 phosphorylation highly impairs MeCP2 binding to DNA in vitro and largely affects its nucleosome binding and chromatin affinity in vivo. Strikingly, the chromatin-binding properties of the global MeCP2 appear also extensively altered during the course of brain maturation. Functional assays reveal that proper temporal regulation of S164 phosphorylation controls the ability of MeCP2 to regulate neuronal morphology. Altogether, our results support the hypothesis of a complex PTM-mediated functional regulation of MeCP2 potentially involving a still poorly characterized epigenetic code. Furthermore, they demonstrate the relevance of the Intervening Domain of MeCP2 for binding to DNA.
Collapse
|
41
|
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
|
42
|
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
|
43
|
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
|
44
|
Hamidi T, Singh AK, Chen T. Genetic alterations of DNA methylation machinery in human diseases. Epigenomics 2015; 7:247-65. [PMID: 25942534 DOI: 10.2217/epi.14.80] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
DNA methylation plays a critical role in the regulation of chromatin structure and gene expression and is involved in a variety of biological processes. The levels and patterns of DNA methylation are regulated by both DNA methyltransferases (DNMT1, DNMT3A and DNMT3B) and 'demethylating' proteins, including the ten-eleven translocation (TET) family of dioxygenases (TET1, TET2 and TET3). The effects of DNA methylation on chromatin and gene expression are largely mediated by methylated DNA 'reader' proteins, including MeCP2. Numerous mutations in DNMTs, TETs and MeCP2 have been identified in cancer and developmental disorders, highlighting the importance of the DNA methylation machinery in human development and physiology. In this review, we describe these mutations and discuss how they may lead to disease phenotypes.
Collapse
Affiliation(s)
- Tewfik Hamidi
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Science Park - Research Division, 1808 Park Road 1C, P. O. Box 389, Smithville, TX 78957, USA
| | | | | |
Collapse
|
45
|
Andoh-Noda T, Akamatsu W, Miyake K, Matsumoto T, Yamaguchi R, Sanosaka T, Okada Y, Kobayashi T, Ohyama M, Nakashima K, Kurosawa H, Kubota T, Okano H. Differentiation of multipotent neural stem cells derived from Rett syndrome patients is biased toward the astrocytic lineage. Mol Brain 2015; 8:31. [PMID: 26012557 PMCID: PMC4446051 DOI: 10.1186/s13041-015-0121-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 04/30/2015] [Indexed: 12/23/2022] Open
Abstract
Background Rett syndrome (RTT) is one of the most prevalent neurodevelopmental disorders in females, caused by de novo mutations in the X-linked methyl CpG-binding protein 2 gene, MECP2. Although abnormal regulation of neuronal genes due to mutant MeCP2 is thought to induce autistic behavior and impaired development in RTT patients, precise cellular mechanisms underlying the aberrant neural progression remain unclear. Results Two sets of isogenic pairs of either wild-type or mutant MECP2-expressing human induced pluripotent stem cell (hiPSC) lines were generated from a single pair of 10-year-old RTT-monozygotic (MZ) female twins. Mutant MeCP2-expressing hiPSC lines did not express detectable MeCP2 protein during any stage of differentiation. The lack of MeCP2 reflected altered gene expression patterns in differentiated neural cells rather than in undifferentiated hiPSCs, as assessed by microarray analysis. Furthermore, MeCP2 deficiency in the neural cell lineage increased astrocyte-specific differentiation from multipotent neural stem cells. Additionally, chromatin immunoprecipitation (ChIP) and bisulfite sequencing assays indicated that anomalous glial fibrillary acidic protein gene (GFAP) expression in the MeCP2-negative, differentiated neural cells resulted from the absence of MeCP2 binding to the GFAP gene. Conclusions An isogenic RTT-hiPSC model demonstrated that MeCP2 participates in the differentiation of neural cells. Moreover, MeCP2 deficiency triggers perturbation of astrocytic gene expression, yielding accelerated astrocyte formation from RTT-hiPSC-derived neural stem cells. These findings are likely to shed new light on astrocytic abnormalities in RTT, and suggest that astrocytes, which are required for neuronal homeostasis and function, might be a new target of RTT therapy. Electronic supplementary material The online version of this article (doi:10.1186/s13041-015-0121-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Tomoko Andoh-Noda
- Division of Medicine and Engineering Science, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37 Takeda, Yamanashi, Kofu, 400-8510, Japan. .,Department of Physiology, Keio University School of Medicine, 35 Shinanomachi,Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Wado Akamatsu
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi,Shinjuku-ku, Tokyo, 160-8582, Japan. .,Center for Genomic and Regenerative Medicine, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
| | - Kunio Miyake
- Department of Epigenetic Medicine, Faculty of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan.
| | - Takuya Matsumoto
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi,Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Ryo Yamaguchi
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi,Shinjuku-ku, Tokyo, 160-8582, Japan. .,Sumitomo Dainipponn Pharma Co. Ltd., Osaka, Osaka, 541-0045, Japan.
| | - Tsukasa Sanosaka
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi,Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Yohei Okada
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi,Shinjuku-ku, Tokyo, 160-8582, Japan. .,Department of Neurology,School of Meidicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan.
| | - Tetsuro Kobayashi
- Department of Dermatology, Keio University School of Medicine, 35 Shinanomachi,Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Manabu Ohyama
- Department of Dermatology, Keio University School of Medicine, 35 Shinanomachi,Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Kinichi Nakashima
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
| | - Hiroshi Kurosawa
- Division of Medicine and Engineering Science, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37 Takeda, Yamanashi, Kofu, 400-8510, Japan.
| | - Takeo Kubota
- Department of Epigenetic Medicine, Faculty of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan.
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi,Shinjuku-ku, Tokyo, 160-8582, Japan.
| |
Collapse
|
46
|
Martínez de Paz A, Sanchez-Mut JV, Samitier-Martí M, Petazzi P, Sáez M, Szczesna K, Huertas D, Esteller M, Ausió J. Circadian cycle-dependent MeCP2 and brain chromatin changes. PLoS One 2015; 10:e0123693. [PMID: 25875630 PMCID: PMC4395115 DOI: 10.1371/journal.pone.0123693] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/06/2015] [Indexed: 11/30/2022] Open
Abstract
Methyl CpG binding protein 2 (MeCP2) is a chromosomal protein of the brain, very abundant especially in neurons, where it plays an important role in the regulation of gene expression. Hence it has the potential to be affected by the mammalian circadian cycle. We performed expression analyses of mice brain frontal cortices obtained at different time points and we found that the levels of MeCP2 are altered circadianly, affecting overall organization of brain chromatin and resulting in a circadian-dependent regulation of well-stablished MeCP2 target genes. Furthermore, this data suggests that alterations of MeCP2 can be responsible for the sleeping disorders arising from pathological stages, such as in autism and Rett syndrome.
Collapse
Affiliation(s)
- Alexia Martínez de Paz
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Jose Vicente Sanchez-Mut
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Mireia Samitier-Martí
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Paolo Petazzi
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Mauricio Sáez
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Karolina Szczesna
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Dori Huertas
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Manel Esteller
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
- Department of Physiological Sciences II, School of Medicine, University of Barcelona, Barcelona, Catalonia, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain
- * E-mail: (ME); (JA)
| | - Juan Ausió
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
- * E-mail: (ME); (JA)
| |
Collapse
|
47
|
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
|
48
|
Bergo A, Strollo M, Gai M, Barbiero I, Stefanelli G, Sertic S, Cobolli Gigli C, Di Cunto F, Kilstrup-Nielsen C, Landsberger N. Methyl-CpG binding protein 2 (MeCP2) localizes at the centrosome and is required for proper mitotic spindle organization. J Biol Chem 2014; 290:3223-37. [PMID: 25527496 DOI: 10.1074/jbc.m114.608125] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in MECP2 cause a broad spectrum of neuropsychiatric disorders of which Rett syndrome represents the best defined condition. Both neuronal and non-neuronal functions of the methyl-binding protein underlie the related pathologies. Nowadays MeCP2 is recognized as a multifunctional protein that modulates its activity depending on its protein partners and posttranslational modifications. However, we are still missing a comprehensive understanding of all MeCP2 functions and their involvement in the related pathologies. The study of human mutations often offers the possibility of clarifying the functions of a protein. Therefore, we decided to characterize a novel MeCP2 phospho-isoform (Tyr-120) whose relevance was suggested by a Rett syndrome patient carrying a Y120D substitution possibly mimicking a constitutively phosphorylated state. Unexpectedly, we found MeCP2 and its Tyr-120 phospho-isoform enriched at the centrosome both in dividing and postmitotic cells. The molecular and functional connection of MeCP2 to the centrosome was further reinforced through cellular and biochemical approaches. We show that, similar to many centrosomal proteins, MeCP2 deficiency causes aberrant spindle geometry, prolonged mitosis, and defects in microtubule nucleation. Collectively, our data indicate a novel function of MeCP2 that might reconcile previous data regarding the role of MeCP2 in cell growth and cytoskeleton stability and that might be relevant to understand some aspects of MeCP2-related conditions. Furthermore, they link the Tyr-120 residue and its phosphorylation to cell division, prompting future studies on the relevance of Tyr-120 for cortical development.
Collapse
Affiliation(s)
- Anna Bergo
- From the Department of Theoretical and Applied Sciences, Section of Biomedical Research, University of Insubria, 21052 Busto Arsizio, Italy
| | - Marta Strollo
- From the Department of Theoretical and Applied Sciences, Section of Biomedical Research, University of Insubria, 21052 Busto Arsizio, Italy
| | - Marta Gai
- the Molecular Biotechnology Center, Department of Molecular Biotechnologies and Health Sciences, University of Turin, 10126 Turin, Italy
| | - Isabella Barbiero
- From the Department of Theoretical and Applied Sciences, Section of Biomedical Research, University of Insubria, 21052 Busto Arsizio, Italy
| | - Gilda Stefanelli
- From the Department of Theoretical and Applied Sciences, Section of Biomedical Research, University of Insubria, 21052 Busto Arsizio, Italy
| | - Sarah Sertic
- the Department of Life Sciences, University of Milan, 20133 Milan, Italy, and
| | - Clementina Cobolli Gigli
- the San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Ferdinando Di Cunto
- the Molecular Biotechnology Center, Department of Molecular Biotechnologies and Health Sciences, University of Turin, 10126 Turin, Italy
| | - Charlotte Kilstrup-Nielsen
- From the Department of Theoretical and Applied Sciences, Section of Biomedical Research, University of Insubria, 21052 Busto Arsizio, Italy
| | - Nicoletta Landsberger
- From the Department of Theoretical and Applied Sciences, Section of Biomedical Research, University of Insubria, 21052 Busto Arsizio, Italy, the San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| |
Collapse
|
49
|
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
|
50
|
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
|