1
|
Chua GNL, Watters JW, Olinares PDB, Begum M, Vostal LE, Luo JA, Chait BT, Liu S. Differential dynamics specify MeCP2 function at nucleosomes and methylated DNA. Nat Struct Mol Biol 2024:10.1038/s41594-024-01373-9. [PMID: 39164525 DOI: 10.1038/s41594-024-01373-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 07/16/2024] [Indexed: 08/22/2024]
Abstract
Methyl-CpG-binding protein 2 (MeCP2) is an essential chromatin-binding protein whose mutations cause Rett syndrome (RTT), a severe neurological disorder that primarily affects young females. The canonical view of MeCP2 as a DNA methylation-dependent transcriptional repressor has proven insufficient to describe its dynamic interaction with chromatin and multifaceted roles in genome organization and gene expression. Here we used single-molecule correlative force and fluorescence microscopy to directly visualize the dynamics of wild-type and RTT-causing mutant MeCP2 on DNA. We discovered that MeCP2 exhibits distinct one-dimensional diffusion kinetics when bound to unmethylated versus CpG methylated DNA, enabling methylation-specific activities such as co-repressor recruitment. We further found that, on chromatinized DNA, MeCP2 preferentially localizes to nucleosomes and stabilizes them from mechanical perturbation. Our results reveal the multimodal behavior of MeCP2 on chromatin that underlies its DNA methylation- and nucleosome-dependent functions and provide a biophysical framework for dissecting the molecular pathology of RTT mutations.
Collapse
Affiliation(s)
- Gabriella N L Chua
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA
- Tri-Institutional PhD Program in Chemical Biology, New York, NY, USA
| | - John W Watters
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA
| | - Paul Dominic B Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Masuda Begum
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA
| | - Lauren E Vostal
- Tri-Institutional PhD Program in Chemical Biology, New York, NY, USA
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY, USA
| | - Joshua A Luo
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Shixin Liu
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA.
| |
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
|
Bracha S, Johnson HJ, Pranckevicius NA, Catto F, Economides AE, Litvinov S, Hassi K, Rigoli MT, Cheroni C, Bonfanti M, Valenti A, Stucchi S, Attreya S, Ross PD, Walsh D, Malachi N, Livne H, Eshel R, Krupalnik V, Levin D, Cobb S, Koumoutsakos P, Caporale N, Testa G, Aguzzi A, Koshy AA, Sheiner L, Rechavi O. Engineering Toxoplasma gondii secretion systems for intracellular delivery of multiple large therapeutic proteins to neurons. Nat Microbiol 2024; 9:2051-2072. [PMID: 39075233 PMCID: PMC11306108 DOI: 10.1038/s41564-024-01750-6] [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: 12/02/2023] [Accepted: 06/05/2024] [Indexed: 07/31/2024]
Abstract
Delivering macromolecules across biological barriers such as the blood-brain barrier limits their application in vivo. Previous work has demonstrated that Toxoplasma gondii, a parasite that naturally travels from the human gut to the central nervous system (CNS), can deliver proteins to host cells. Here we engineered T. gondii's endogenous secretion systems, the rhoptries and dense granules, to deliver multiple large (>100 kDa) therapeutic proteins into neurons via translational fusions to toxofilin and GRA16. We demonstrate delivery in cultured cells, brain organoids and in vivo, and probe protein activity using imaging, pull-down assays, scRNA-seq and fluorescent reporters. We demonstrate robust delivery after intraperitoneal administration in mice and characterize 3D distribution throughout the brain. As proof of concept, we demonstrate GRA16-mediated brain delivery of the MeCP2 protein, a putative therapeutic target for Rett syndrome. By characterizing the potential and current limitations of the system, we aim to guide future improvements that will be required for broader application.
Collapse
Affiliation(s)
- Shahar Bracha
- Department of Neurobiology, Biochemistry and Biophysics, Wise Faculty of Life Sciences and Sagol School for Neuroscience, Tel Aviv University, Tel Aviv, Israel.
- McGovern Institute for Brain Research, MIT, Cambridge, MA, USA.
| | - Hannah J Johnson
- Neuroscience Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, USA
- Departments of Neurology and Immunobiology, College of Medicine, and BIO5 Institute, University of Arizona, Tucson, AZ, USA
| | - Nicole A Pranckevicius
- Centre for Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Francesca Catto
- Institute of Neuropathology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Athena E Economides
- Institute of Neuropathology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Sergey Litvinov
- Computational Science and Engineering Laboratory, School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Karoliina Hassi
- Centre for Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Marco Tullio Rigoli
- Human Technopole, Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | - Cristina Cheroni
- Human Technopole, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | | | - Alessia Valenti
- Human Technopole, Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | - Sarah Stucchi
- Human Technopole, Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | - Shruti Attreya
- Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, USA
| | - Paul D Ross
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Daniel Walsh
- Centre for Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | | | | | | | | | | | - Stuart Cobb
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Petros Koumoutsakos
- Computational Science and Engineering Laboratory, School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Nicolò Caporale
- Human Technopole, Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | - Giuseppe Testa
- Human Technopole, Milan, Italy.
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy.
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy.
| | - Adriano Aguzzi
- Institute of Neuropathology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Anita A Koshy
- Departments of Neurology and Immunobiology, College of Medicine, and BIO5 Institute, University of Arizona, Tucson, AZ, USA.
| | - Lilach Sheiner
- Centre for Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
| | - Oded Rechavi
- Department of Neurobiology, Biochemistry and Biophysics, Wise Faculty of Life Sciences and Sagol School for Neuroscience, Tel Aviv University, Tel Aviv, Israel.
| |
Collapse
|
4
|
Dong P, Zhang S, Gandin V, Xie L, Wang L, Lemire AL, Li W, Otsuna H, Kawase T, Lander AD, Chang HY, Liu ZJ. Cohesin prevents cross-domain gene coactivation. Nat Genet 2024; 56:1654-1664. [PMID: 39048795 PMCID: PMC11319207 DOI: 10.1038/s41588-024-01852-1] [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: 02/08/2023] [Accepted: 06/27/2024] [Indexed: 07/27/2024]
Abstract
The contrast between the disruption of genome topology after cohesin loss and the lack of downstream gene expression changes instigates intense debates regarding the structure-function relationship between genome and gene regulation. Here, by analyzing transcriptome and chromatin accessibility at the single-cell level, we discover that, instead of dictating population-wide gene expression levels, cohesin supplies a general function to neutralize stochastic coexpression tendencies of cis-linked genes in single cells. Notably, cohesin loss induces widespread gene coactivation and chromatin co-opening tens of million bases apart in cis. Spatial genome and protein imaging reveals that cohesin prevents gene co-bursting along the chromosome and blocks spatial mixing of transcriptional hubs. Single-molecule imaging shows that cohesin confines the exploration of diverse enhancer and core promoter binding transcriptional regulators. Together, these results support that cohesin arranges nuclear topology to control gene coexpression in single cells.
Collapse
Affiliation(s)
- Peng Dong
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
| | - Shu Zhang
- Center for Personal Dynamic Regulomes and Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Valentina Gandin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Liangqi Xie
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Cancer Biology and Infection Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Lihua Wang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Andrew L Lemire
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Wenhong Li
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Hideo Otsuna
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Takashi Kawase
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Arthur D Lander
- Department of Developmental and Cell Biology, Center for Complex Biological Systems, University of California, Irvine, CA, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes and Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Zhe J Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
| |
Collapse
|
5
|
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
|
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
|
Chai Y, Lee SSY, Shillington A, Du X, Fok CKM, Yeung KC, Siu GKY, Yuan S, Zheng Z, Tsang HWS, Gu S, Chen Y, Ye T, Ip JPK. Non-canonical C-terminal variant of MeCP2 R344W exhibits enhanced degradation rate. IBRO Neurosci Rep 2023; 15:218-224. [PMID: 37822516 PMCID: PMC10562907 DOI: 10.1016/j.ibneur.2023.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 09/21/2023] [Indexed: 10/13/2023] Open
Abstract
Rett Syndrome (RTT) is a neurodevelopmental disorder caused by pathogenic variants in the MECP2 gene. While the majority of RTT-causing variants are clustered in the methyl-CpG binding domain and NCoR/SMRT interaction domain, we report a female patient with a functionally uncharacterized MECP2 variant in the C-terminal domain, c.1030C>T (R344W). We functionally characterized MECP2-R344W in terms of protein stability, NCoR/SMRT complex interaction, and protein nuclear localization in vitro. MECP2-R344W cells showed an increased protein degradation rate without significant change in NCoR/SMRT complex interaction and nuclear localization pattern, suggesting that enhanced MECP2 degradation is sufficient to cause a Rett Syndrome-like phenotype. This study highlights the pathogenicity of the C-terminal domain in Rett Syndrome, and demonstrates the potential of targeting MECP2 protein stability as a therapeutic approach.
Collapse
Affiliation(s)
- Yue Chai
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Chinese Academy of Sciences Key Laboratory of Brain Connectome and Manipulation, Shenzhen Key Laboratory of Translational Research for Brain Diseases, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science—Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Sharon Shui Ying Lee
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Amelle Shillington
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Xiaoli Du
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Catalina Ka Man Fok
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Kam Chun Yeung
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Gavin Ka Yu Siu
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Shiyang Yuan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Zhongyu Zheng
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Hayley Wing Sum Tsang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Shen Gu
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Gerald Choa Neuroscience Institute, The Chinese University of Hong Kong, Hong Kong, China
- CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Yu Chen
- Chinese Academy of Sciences Key Laboratory of Brain Connectome and Manipulation, Shenzhen Key Laboratory of Translational Research for Brain Diseases, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science—Shenzhen Fundamental Research Institutions, Shenzhen, China
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science—Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Tao Ye
- Chinese Academy of Sciences Key Laboratory of Brain Connectome and Manipulation, Shenzhen Key Laboratory of Translational Research for Brain Diseases, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science—Shenzhen Fundamental Research Institutions, Shenzhen, China
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science—Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Jacque Pak Kan Ip
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Gerald Choa Neuroscience Institute, The Chinese University of Hong Kong, Hong Kong, China
- CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| |
Collapse
|
8
|
Tzeng CP, Whitwam T, Boxer LD, Li E, Silberfeld A, Trowbridge S, Mei K, Lin C, Shamah R, Griffith EC, Renthal W, Chen C, Greenberg ME. Activity-induced MeCP2 phosphorylation regulates retinogeniculate synapse refinement. Proc Natl Acad Sci U S A 2023; 120:e2310344120. [PMID: 37871205 PMCID: PMC10623012 DOI: 10.1073/pnas.2310344120] [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: 06/20/2023] [Accepted: 09/25/2023] [Indexed: 10/25/2023] Open
Abstract
Mutations in MECP2 give rise to Rett syndrome (RTT), an X-linked neurodevelopmental disorder that results in broad cognitive impairments in females. While the exact etiology of RTT symptoms remains unknown, one possible explanation for its clinical presentation is that loss of MECP2 causes miswiring of neural circuits due to defects in the brain's capacity to respond to changes in neuronal activity and sensory experience. Here, we show that MeCP2 is phosphorylated at four residues in the mouse brain (S86, S274, T308, and S421) in response to neuronal activity, and we generate a quadruple knock-in (QKI) mouse line in which all four activity-dependent sites are mutated to alanines to prevent phosphorylation. QKI mice do not display overt RTT phenotypes or detectable gene expression changes in two brain regions. However, electrophysiological recordings from the retinogeniculate synapse of QKI mice reveal that while synapse elimination is initially normal at P14, it is significantly compromised at P20. Notably, this phenotype is distinct from the synapse refinement defect previously reported for Mecp2 null mice, where synapses initially refine but then regress after the third postnatal week. We thus propose a model in which activity-induced phosphorylation of MeCP2 is critical for the proper timing of retinogeniculate synapse maturation specifically during the early postnatal period.
Collapse
Affiliation(s)
| | - Tess Whitwam
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
- Program in Neuroscience, Harvard Medical School, Boston, MA02115
| | - Lisa D. Boxer
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - Emmy Li
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | | | - Sara Trowbridge
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - Kevin Mei
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - Cindy Lin
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - Rebecca Shamah
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - Eric C. Griffith
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - William Renthal
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - Chinfei Chen
- Department of Neurology, F.M. Kirby Neurobiology Center, Children’s Hospital, Boston, MA02115
| | | |
Collapse
|
9
|
West AE. Imaging the binding of MECP2 to DNA. Genes Dev 2023; 37:863-864. [PMID: 37914350 PMCID: PMC10691463 DOI: 10.1101/gad.351285.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Mutations in the methyl-DNA binding domain of MECP2 cause Rett syndrome; however, distinct mutations are associated with different severity of the disease. Live-cell imaging and single-molecule tracking are sensitive methods to quantify the DNA binding affinity and diffusion dynamics of nuclear proteins. In this issue of Genes & Development, Zhou and colleagues (pp. 883-900) used these imaging methods to quantitatively describe the partial loss of DNA binding resulting from a novel pathological MECP2 mutation with intermediate disease severity. These data demonstrate how single-molecule tracking can advance understanding of the molecular mechanisms connecting MECP2 mutations with Rett syndrome pathophysiology.
Collapse
Affiliation(s)
- Anne E West
- Department of Neurobiology, Duke University School of Medicine, Durham, North Carolina 27710, USA
| |
Collapse
|
10
|
Zhou J, Cattoglio C, Shao Y, Tirumala HP, Vetralla C, Bajikar SS, Li Y, Chen H, Wang Q, Wu Z, Tang B, Zahabiyon M, Bajic A, Meng X, Ferrie JJ, LaGrone A, Zhang P, Kim JJ, Tang J, Liu Z, Darzacq X, Heintz N, Tjian R, Zoghbi HY. A novel pathogenic mutation of MeCP2 impairs chromatin association independent of protein levels. Genes Dev 2023; 37:883-900. [PMID: 37890975 PMCID: PMC10691473 DOI: 10.1101/gad.350733.123] [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: 04/20/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023]
Abstract
Loss-of-function mutations in MECP2 cause Rett syndrome (RTT), a severe neurological disorder that mainly affects girls. Mutations in MECP2 do occur in males occasionally and typically cause severe encephalopathy and premature lethality. Recently, we identified a missense mutation (c.353G>A, p.Gly118Glu [G118E]), which has never been seen before in MECP2, in a young boy who suffered from progressive motor dysfunction and developmental delay. To determine whether this variant caused the clinical symptoms and study its functional consequences, we established two disease models, including human neurons from patient-derived iPSCs and a knock-in mouse line. G118E mutation partially reduces MeCP2 abundance and its DNA binding, and G118E mice manifest RTT-like symptoms seen in the patient, affirming the pathogenicity of this mutation. Using live-cell and single-molecule imaging, we found that G118E mutation alters MeCP2's chromatin interaction properties in live neurons independently of its effect on protein levels. Here we report the generation and characterization of RTT models of a male hypomorphic variant and reveal new insight into the mechanism by which this pathological mutation affects MeCP2's chromatin dynamics. Our ability to quantify protein dynamics in disease models lays the foundation for harnessing high-resolution single-molecule imaging as the next frontier for developing innovative therapies for RTT and other diseases.
Collapse
Affiliation(s)
- Jian Zhou
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Claudia Cattoglio
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, Berkeley, California 94720, USA
| | - Yingyao Shao
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Harini P Tirumala
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Carlo Vetralla
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, Berkeley, California 94720, USA
- School of Medicine and Surgery, University of Milan-Bicocca, Milano 20126, Italy
| | - Sameer S Bajikar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Yan Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Hu Chen
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Qi Wang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Zhenyu Wu
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Bing Tang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Mahla Zahabiyon
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Aleksandar Bajic
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Xiangling Meng
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jack J Ferrie
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, Berkeley, California 94720, USA
| | - Anel LaGrone
- Advanced Technology Cores, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Ping Zhang
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jean J Kim
- Advanced Technology Cores, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Molecular and Cellular Biology, Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jianrong Tang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Zhandong Liu
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Xavier Darzacq
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10065, USA
| | - Robert Tjian
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, California Institute for Regenerative Medicine (CIRM) Center of Excellence, University of California, Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, Berkeley, California 94720, USA
| | - Huda Y Zoghbi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA;
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA
| |
Collapse
|
11
|
Okamoto K, Fujita H, Okada Y, Shinkai S, Onami S, Abe K, Fujimoto K, Sasaki K, Shioi G, Watanabe TM. Single-molecule tracking of Nanog and Oct4 in living mouse embryonic stem cells uncovers a feedback mechanism of pluripotency maintenance. EMBO J 2023; 42:e112305. [PMID: 37609947 PMCID: PMC10505915 DOI: 10.15252/embj.2022112305] [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: 08/05/2022] [Revised: 06/13/2023] [Accepted: 06/22/2023] [Indexed: 08/24/2023] Open
Abstract
Nanog and Oct4 are core transcription factors that form part of a gene regulatory network to regulate hundreds of target genes for pluripotency maintenance in mouse embryonic stem cells (ESCs). To understand their function in the pluripotency maintenance, we visualised and quantified the dynamics of single molecules of Nanog and Oct4 in a mouse ESCs during pluripotency loss. Interestingly, Nanog interacted longer with its target loci upon reduced expression or at the onset of differentiation, suggesting a feedback mechanism to maintain the pluripotent state. The expression level and interaction time of Nanog and Oct4 correlate with their fluctuation and interaction frequency, respectively, which in turn depend on the ESC differentiation status. The DNA viscoelasticity near the Oct4 target locus remained flexible during differentiation, supporting its role either in chromatin opening or a preferred binding to uncondensed chromatin regions. Based on these results, we propose a new negative feedback mechanism for pluripotency maintenance via the DNA condensation state-dependent interplay of Nanog and Oct4.
Collapse
Affiliation(s)
- Kazuko Okamoto
- Laboratory for Comprehensive BioimagingRIKEN Center for Biosystems Dynamics Research (BDR)KobeJapan
- Amphibian Research CenterHiroshima UniversityHiroshimaJapan
| | - Hideaki Fujita
- Department of Stem Cell Biology, Research Institute for Radiation Biology and MedicineHiroshima UniversityHigashi‐HiroshimaJapan
| | - Yasushi Okada
- Laboratory for Cell Polarity RegulationRIKEN Center for Biosystems Dynamics Research (BDR)OsakaJapan
- Department of Cell BiologyGraduate School of Medicine, The University of TokyoTokyoJapan
- Department of PhysicsUniversal Biology Institute (UBI)Graduate School of Science, The University of TokyoTokyoJapan
- International Research Center for Neurointelligence (WPI‐IRCN)Institutes for Advanced Study, The University of TokyoTokyoJapan
| | - Soya Shinkai
- Laboratory for Developmental DynamicsRIKEN Center for Biosystems Dynamics Research (BDR)KobeJapan
- Research Center for the Mathematics on Chromatin Live Dynamics (RcMcD)Hiroshima UniversityHiroshimaJapan
| | - Shuichi Onami
- Laboratory for Developmental DynamicsRIKEN Center for Biosystems Dynamics Research (BDR)KobeJapan
| | - Kuniya Abe
- Technology and Development Team for Mammalian Genome DynamicsRIKEN BioResource Research Center (BRC)TsukubaJapan
| | - Kenta Fujimoto
- Department of Stem Cell Biology, Research Institute for Radiation Biology and MedicineHiroshima UniversityHigashi‐HiroshimaJapan
| | - Kensuke Sasaki
- Laboratory for Comprehensive BioimagingRIKEN Center for Biosystems Dynamics Research (BDR)KobeJapan
| | - Go Shioi
- Laboratory for Comprehensive BioimagingRIKEN Center for Biosystems Dynamics Research (BDR)KobeJapan
| | - Tomonobu M Watanabe
- Laboratory for Comprehensive BioimagingRIKEN Center for Biosystems Dynamics Research (BDR)KobeJapan
- Department of Stem Cell Biology, Research Institute for Radiation Biology and MedicineHiroshima UniversityHigashi‐HiroshimaJapan
| |
Collapse
|
12
|
Rodrigues DC, Mufteev M, Yuki KE, Narula A, Wei W, Piekna A, Liu J, Pasceri P, Rissland OS, Wilson MD, Ellis J. Buffering of transcription rate by mRNA half-life is a conserved feature of Rett syndrome models. Nat Commun 2023; 14:1896. [PMID: 37019888 PMCID: PMC10076348 DOI: 10.1038/s41467-023-37339-6] [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: 01/26/2022] [Accepted: 03/13/2023] [Indexed: 04/07/2023] Open
Abstract
Transcriptional changes in Rett syndrome (RTT) are assumed to directly correlate with steady-state mRNA levels, but limited evidence in mice suggests that changes in transcription can be compensated by post-transcriptional regulation. We measure transcription rate and mRNA half-life changes in RTT patient neurons using RATEseq, and re-interpret nuclear and whole-cell RNAseq from Mecp2 mice. Genes are dysregulated by changing transcription rate or half-life and are buffered when both change. We utilized classifier models to predict the direction of transcription rate changes and find that combined frequencies of three dinucleotides are better predictors than CA and CG. MicroRNA and RNA-binding Protein (RBP) motifs are enriched in 3'UTRs of genes with half-life changes. Nuclear RBP motifs are enriched on buffered genes with increased transcription rate. We identify post-transcriptional mechanisms in humans and mice that alter half-life or buffer transcription rate changes when a transcriptional modulator gene is mutated in a neurodevelopmental disorder.
Collapse
Affiliation(s)
- Deivid C Rodrigues
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Marat Mufteev
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Kyoko E Yuki
- Genetics & Genome Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Ashrut Narula
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Molecular Medicine, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Wei Wei
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Alina Piekna
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Jiajie Liu
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Peter Pasceri
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Olivia S Rissland
- Molecular Medicine, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- RNA Bioscience Initiative and Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Michael D Wilson
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Genetics & Genome Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - James Ellis
- Developmental & Stem Cell Biology, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.
| |
Collapse
|
13
|
Chhatbar K, Connelly J, Webb S, Kriaucionis S, Bird A. A critique of the hypothesis that CA repeats are primary targets of neuronal MeCP2. Life Sci Alliance 2022; 5:5/12/e202201522. [PMID: 36122935 PMCID: PMC9485053 DOI: 10.26508/lsa.202201522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/07/2022] [Accepted: 09/07/2022] [Indexed: 11/24/2022] Open
Abstract
The DNA-binding protein MeCP2 is reported to bind methylated cytosine in CG and CA motifs in genomic DNA, but it was recently proposed that arrays of tandemly repeated CA containing either methylated or hydroxymethylated cytosine are the primary targets for MeCP2 binding and function. Here we investigated the predictions of this hypothesis using a range of published datasets. We failed to detect enrichment of cytosine modification at genomic CA repeat arrays in mouse brain regions and found no evidence for preferential MeCP2 binding at CA repeats. Moreover, we did not observe a correlation between the CA repeat density near genes and their degree of transcriptional deregulation when MeCP2 was absent. Our results do not provide support for the hypothesis that CA repeats are key mediators of MeCP2 function. Instead, we found that CA repeats are subject to CAC methylation to a degree that is typical of the surrounding genome and contribute modestly to MeCP2-mediated modulation of gene expression in accordance with their content of this canonical target motif.
Collapse
Affiliation(s)
- Kashyap Chhatbar
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, Edinburgh, UK.,Informatics Forum, School of Informatics, University of Edinburgh, Edinburgh, UK
| | - John Connelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, Edinburgh, UK
| | - Shaun Webb
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, Edinburgh, UK
| | | | - Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, Edinburgh, UK
| |
Collapse
|
14
|
MeCP2 inhibits ischemic neuronal injury by enhancing methylation of the FOXO3a promoter to repress the SPRY2-ZEB1 axis. Exp Mol Med 2022; 54:1076-1085. [PMID: 35915222 PMCID: PMC9440071 DOI: 10.1038/s12276-022-00790-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 03/21/2022] [Accepted: 04/06/2022] [Indexed: 11/08/2022] Open
Abstract
AbstractMethyl CpG binding protein 2 (MeCP2) is involved in nerve regeneration following ischemic stroke, but the related mechanism remains unclear. Here, we found low MeCP2 expression in hippocampal tissues. Using functional analysis, we demonstrated that MeCP2 accelerated FOXO3a methylation and subsequently inhibited its expression, thus repressing the apoptosis of neuronal cells. Mechanistically, FOXO3a could bind to the promoter region of SPRY2, consequently inducing its transcription and promoting the expression of the downstream target gene ZEB1. Altogether, our study revealed that overexpression of MeCP2 can protect mice against ischemic brain injury via disruption of the FOXO3a/SPRY2/ZEB1 signaling axis. Our results identify ectopic expression of MeCP2 as a therapeutic target in ischemic stroke.
Collapse
|
15
|
Kuchler O, Gerlach J, Vomhof T, Hettich J, Steinmetz J, Gebhardt JCM, Michaelis J, Knöll B. Single-molecule tracking (SMT) and localization of SRF and MRTF transcription factors during neuronal stimulation and differentiation. Open Biol 2022; 12:210383. [PMID: 35537478 PMCID: PMC9090491 DOI: 10.1098/rsob.210383] [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] [Indexed: 01/04/2023] Open
Abstract
In cells, proteins encoded by the same gene do not all behave uniformly but engage in functional subpopulations induced by spatial or temporal segregation. While conventional microscopy has limitations in revealing such spatial and temporal diversity, single-molecule tracking (SMT) microscopy circumvented this problem and allows for high-resolution imaging and quantification of dynamic single-molecule properties. Particularly in the nucleus, SMT has identified specific DNA residence times of transcription factors (TFs), DNA-bound TF fractions and positions of transcriptional hot-spots upon cell stimulation. By contrast to cell stimulation, SMT has not been employed to follow dynamic TF changes along stages of cell differentiation. Herein, we analysed the serum response factor (SRF), a TF involved in the differentiation of many cell types to study nuclear single-molecule dynamics in neuronal differentiation. Our data in living mouse hippocampal neurons show dynamic changes in SRF DNA residence time and SRF DNA-bound fraction between the stages of adhesion, neurite growth and neurite differentiation in axon and dendrites. Using TALM (tracking and localization microscopy), we identified nuclear positions of SRF clusters and observed changes in their numbers and size during differentiation. Furthermore, we show that the SRF cofactor MRTF-A (myocardin-related TF or MKL1) responds to cell activation by enhancing the long-bound DNA fraction. Finally, a first SMT colocalization study of two proteins was performed in living cells showing enhanced SRF/MRTF-A colocalization upon stimulation. In summary, SMT revealed modulation of dynamic TF properties during cell stimulation and differentiation.
Collapse
Affiliation(s)
- Oliver Kuchler
- Institute of Neurobiochemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany,Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Jule Gerlach
- Institute of Neurobiochemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany,Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Thomas Vomhof
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Johannes Hettich
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Julia Steinmetz
- Department of Statistics, TU Dortmund University, August-Schmidt Straße 1, 44227 Dortmund, Germany
| | | | - Jens Michaelis
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Bernd Knöll
- Institute of Neurobiochemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| |
Collapse
|
16
|
de Jonge WJ, Patel HP, Meeussen JVW, Lenstra TL. Following the tracks: how transcription factor binding dynamics control transcription. Biophys J 2022; 121:1583-1592. [PMID: 35337845 PMCID: PMC9117886 DOI: 10.1016/j.bpj.2022.03.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/28/2022] [Accepted: 03/21/2022] [Indexed: 11/29/2022] Open
Abstract
Transcription, the process of copying genetic information from DNA to messenger RNA, is regulated by sequence-specific DNA binding proteins known as transcription factors (TFs). Recent advances in single-molecule tracking (SMT) technologies have enabled visualization of individual TF molecules as they diffuse and interact with the DNA in the context of living cells. These SMT studies have uncovered multiple populations of DNA binding events characterized by their distinctive DNA residence times. In this perspective, we review recent insights into how these residence times relate to specific and non-specific DNA binding, as well as the contribution of TF domains on the DNA binding dynamics. We discuss different models that aim to link transient DNA binding by TFs to bursts of transcription and present an outlook for how future advances in microscopy development may broaden our understanding of the dynamics of the molecular steps that underlie transcription activation.
Collapse
Affiliation(s)
- Wim J de Jonge
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Heta P Patel
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Joseph V W Meeussen
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, the Netherlands
| | - Tineke L Lenstra
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, the Netherlands.
| |
Collapse
|
17
|
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
|
18
|
Stoyanova E, Riad M, Rao A, Heintz N. 5-Hydroxymethylcytosine-mediated active demethylation is required for mammalian neuronal differentiation and function. eLife 2021; 10:66973. [PMID: 34919053 PMCID: PMC8683082 DOI: 10.7554/elife.66973] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 11/02/2021] [Indexed: 01/02/2023] Open
Abstract
Although high levels of 5-hydroxymethylcytosine (5hmC) accumulate in mammalian neurons, our knowledge of its roles in terminal differentiation or as an intermediate in active DNA demethylation is incomplete. We report high-resolution mapping of DNA methylation and hydroxymethylation, chromatin accessibility, and histone marks in developing postmitotic Purkinje cells (PCs) in Mus musculus. Our data reveal new relationships between PC transcriptional and epigenetic programs, and identify a class of genes that lose both 5-methylcytosine (5mC) and 5hmC during terminal differentiation. Deletion of the 5hmC writers Tet1, Tet2, and Tet3 from postmitotic PCs prevents loss of 5mC and 5hmC in regulatory domains and gene bodies, and hinders transcriptional and epigenetic developmental transitions. Our data demonstrate that Tet-mediated active DNA demethylation occurs in vivo, and that acquisition of the precise molecular properties of adult PCs require continued oxidation of 5mC to 5hmC during the final phases of differentiation. At birth, the mammalian brain contains tens of billions of neurons. Although the number does not increase much as the animal grows, there are many dramatic changes to their size and structure. These changes allow the neurons to communicate with one another, develop into networks, and learn the tasks of the adult brain. One way that these changes occur is by the accumulation of chemical marks on each neuron’s DNA that help dictate which genes switch on, and which turn off. One of the most common ways that DNA can be marked is through the addition of a chemical group called a methyl group to one of the four DNA bases, cytosine. This process is called methylation. When methylation occurs, cytosine becomes 5-methylcytosine, or 5mC for short. In 2009, researchers found another modification present in the DNA in the brain: 5-hydroxymethylcytosine, or 5hmC. This modification appears when a group of proteins called the Tet hydroxylases turn 5mC into 5hmC. Converting 5mC to 5hmC normally helps cells remove marks on their DNA before they divide and expand. This is important because the newly generated cells need to be able to accumulate their own methylation marks to perform their roles properly. However, neurons in the brain accumulate 5hmC after birth, when the cells are no longer dividing, indicating that 5hmC may be required for the neurons to mature. Stoyanova et al. set out to determine whether mouse neurons need 5hmC to get their adult characteristics by tracking the chemical changes that occur in DNA from birth to adulthood. Some of the mice they tested produced 5hmC normally, while others lacked the genes necessary to make the Tet proteins in a specific class of neurons, preventing them from converting 5mC to 5hmC as they differentiate. The results reveal that neurons do not mature properly if 5hmC is not produced continuously following the first week of life. This is because neurons need to have the right genes switched on and off to differentiate correctly, and this only happens when 5hmC accumulates in some genes, while 5hmC and 5mC are removed from others. The data highlight the role of the Tet proteins, which convert 5mC into 5hmC, in preparing the marks for removal and demonstrate that active removal of these marks is essential for neuronal differentiation. Given the role of 5hmC in the development of neurons, it is possible that problems in this system could contribute to brain disorders. Further studies aimed at understanding how cells control 5hmC levels could lead to new ways to improve brain health. Research has also shown that if dividing cells lose the ability to make 5hmC, they can become cancerous. Future work could explain more about how and why this happens.
Collapse
Affiliation(s)
- Elitsa Stoyanova
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Michael Riad
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Anjana Rao
- Sanford Consortium for Regenerative Medicine, La Jolla, United States.,La Jolla Institute for Allergy and Immunology, La Jolla, United States.,Department of Pharmacology, University of California San Diego, La Jolla, United States
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| |
Collapse
|
19
|
Wang Z, Deng W. Dynamic transcription regulation at the single-molecule level. Dev Biol 2021; 482:67-81. [PMID: 34896367 DOI: 10.1016/j.ydbio.2021.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 11/14/2021] [Accepted: 11/15/2021] [Indexed: 02/07/2023]
Abstract
Cell fate changes during development, differentiation, and reprogramming are largely controlled at the transcription level. The DNA-binding transcription factors (TFs) often act in a combinatorial fashion to alter chromatin states and drive cell type-specific gene expression. Recent advances in fluorescent microscopy technologies have enabled direct visualization of biomolecules involved in the process of transcription and its regulatory events at the single-molecule level in living cells. Remarkably, imaging and tracking individual TF molecules at high temporal and spatial resolution revealed that they are highly dynamic in searching and binding cognate targets, rather than static and binding constantly. In combination with investigation using techniques from biochemistry, structure biology, genetics, and genomics, a more well-rounded view of transcription regulation is emerging. In this review, we briefly cover the technical aspects of live-cell single-molecule imaging and focus on the biological relevance and interpretation of the single-molecule dynamic features of transcription regulatory events observed in the native chromatin environment of living eukaryotic cells. We also discuss how these dynamic features might shed light on mechanistic understanding of transcription regulation.
Collapse
Affiliation(s)
- Zuhui Wang
- Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Wulan Deng
- Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China; Beijing Advanced Innovation Center for Genomics (ICG), Peking University, Beijing, 100871, China; Peking-Tsinghua Center for Life Sciences (CLS), Peking University, Beijing, 100871, China; School of Life Sciences, Peking University, Beijing, 100871, China.
| |
Collapse
|
20
|
Liu S, Wang S, Zou L, Xiong W. Mechanisms in cochlear hair cell mechano-electrical transduction for acquisition of sound frequency and intensity. Cell Mol Life Sci 2021; 78:5083-5094. [PMID: 33871677 PMCID: PMC11072359 DOI: 10.1007/s00018-021-03840-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 03/30/2021] [Accepted: 04/09/2021] [Indexed: 10/21/2022]
Abstract
Sound signals are acquired and digitized in the cochlea by the hair cells that further transmit the coded information to the central auditory pathways. Any defect in hair cell function may induce problems in the auditory system and hearing-based brain function. In the past 2 decades, our understanding of auditory transduction has been substantially deepened because of advances in molecular, structural, and functional studies. Results from these experiments can be perfectly embedded in the previously established profile from anatomical, histological, genetic, and biophysical research. This review aims to summarize the progress on the molecular and cellular mechanisms of the mechano-electrical transduction (MET) channel in the cochlear hair cells, which is involved in the acquisition of sound frequency and intensity-the two major parameters of an acoustic cue. We also discuss recent studies on TMC1, the molecule likely to form the MET channel pore.
Collapse
Affiliation(s)
- Shuang Liu
- School of Life Sciences, Tsinghua University, 1 Qinghuayuan, Beijing, 100084, China
- IDG/McGovern Institute for Brain Research at Tsinghua University, Tsinghua University, 1 Qinghuayuan, Beijing, 100084, China
| | - Shufeng Wang
- School of Life Sciences, Tsinghua University, 1 Qinghuayuan, Beijing, 100084, China
- IDG/McGovern Institute for Brain Research at Tsinghua University, Tsinghua University, 1 Qinghuayuan, Beijing, 100084, China
| | - Linzhi Zou
- School of Life Sciences, Tsinghua University, 1 Qinghuayuan, Beijing, 100084, China
- IDG/McGovern Institute for Brain Research at Tsinghua University, Tsinghua University, 1 Qinghuayuan, Beijing, 100084, China
| | - Wei Xiong
- School of Life Sciences, Tsinghua University, 1 Qinghuayuan, Beijing, 100084, China.
- IDG/McGovern Institute for Brain Research at Tsinghua University, Tsinghua University, 1 Qinghuayuan, Beijing, 100084, China.
| |
Collapse
|
21
|
Sharifi O, Yasui DH. The Molecular Functions of MeCP2 in Rett Syndrome Pathology. Front Genet 2021; 12:624290. [PMID: 33968128 PMCID: PMC8102816 DOI: 10.3389/fgene.2021.624290] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/08/2021] [Indexed: 12/13/2022] Open
Abstract
MeCP2 protein, encoded by the MECP2 gene, binds to DNA and affects transcription. Outside of this activity the true range of MeCP2 function is still not entirely clear. As MECP2 gene mutations cause the neurodevelopmental disorder Rett syndrome in 1 in 10,000 female births, much of what is known about the biologic function of MeCP2 comes from studying human cell culture models and rodent models with Mecp2 gene mutations. In this review, the full scope of MeCP2 research available in the NIH Pubmed (https://pubmed.ncbi.nlm.nih.gov/) data base to date is considered. While not all original research can be mentioned due to space limitations, the main aspects of MeCP2 and Rett syndrome research are discussed while highlighting the work of individual researchers and research groups. First, the primary functions of MeCP2 relevant to Rett syndrome are summarized and explored. Second, the conflicting evidence and controversies surrounding emerging aspects of MeCP2 biology are examined. Next, the most obvious gaps in MeCP2 research studies are noted. Finally, the most recent discoveries in MeCP2 and Rett syndrome research are explored with a focus on the potential and pitfalls of novel treatments and therapies.
Collapse
Affiliation(s)
- Osman Sharifi
- LaSalle Laboratory, Department of Medical Microbiology and Immunology, UC Davis School of Medicine, Davis, CA, United States
| | - Dag H Yasui
- LaSalle Laboratory, Department of Medical Microbiology and Immunology, UC Davis School of Medicine, Davis, CA, United States
| |
Collapse
|
22
|
Choquet D, Sainlos M, Sibarita JB. Advanced imaging and labelling methods to decipher brain cell organization and function. Nat Rev Neurosci 2021; 22:237-255. [PMID: 33712727 DOI: 10.1038/s41583-021-00441-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2021] [Indexed: 01/31/2023]
Abstract
The brain is arguably the most complex organ. The branched and extended morphology of nerve cells, their subcellular complexity, the multiplicity of brain cell types as well as their intricate connectivity and the scattering properties of brain tissue present formidable challenges to the understanding of brain function. Neuroscientists have often been at the forefront of technological and methodological developments to overcome these hurdles to visualize, quantify and modify cell and network properties. Over the last few decades, the development of advanced imaging methods has revolutionized our approach to explore the brain. Super-resolution microscopy and tissue imaging approaches have recently exploded. These instrumentation-based innovations have occurred in parallel with the development of new molecular approaches to label protein targets, to evolve new biosensors and to target them to appropriate cell types or subcellular compartments. We review the latest developments for labelling and functionalizing proteins with small localization and functionalized reporters. We present how these molecular tools are combined with the development of a wide variety of imaging methods that break either the diffraction barrier or the tissue penetration depth limits. We put these developments in perspective to emphasize how they will enable step changes in our understanding of the brain.
Collapse
Affiliation(s)
- Daniel Choquet
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France. .,University of Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, Bordeaux, France.
| | - Matthieu Sainlos
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France.
| | - Jean-Baptiste Sibarita
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France.
| |
Collapse
|
23
|
Tillotson R, Cholewa-Waclaw J, Chhatbar K, Connelly JC, Kirschner SA, Webb S, Koerner MV, Selfridge J, Kelly DA, De Sousa D, Brown K, Lyst MJ, Kriaucionis S, Bird A. Neuronal non-CG methylation is an essential target for MeCP2 function. Mol Cell 2021; 81:1260-1275.e12. [PMID: 33561390 PMCID: PMC7980222 DOI: 10.1016/j.molcel.2021.01.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/17/2020] [Accepted: 01/07/2021] [Indexed: 02/07/2023]
Abstract
DNA methylation is implicated in neuronal biology via the protein MeCP2, the mutation of which causes Rett syndrome. MeCP2 recruits the NCOR1/2 co-repressor complexes to methylated cytosine in the CG dinucleotide, but also to sites of non-CG methylation, which are abundant in neurons. To test the biological significance of the dual-binding specificity of MeCP2, we replaced its DNA binding domain with an orthologous domain from MBD2, which can only bind mCG motifs. Knockin mice expressing the domain-swap protein displayed severe Rett-syndrome-like phenotypes, indicating that normal brain function requires the interaction of MeCP2 with sites of non-CG methylation, specifically mCAC. The results support the notion that the delayed onset of Rett syndrome is due to the simultaneous post-natal accumulation of mCAC and its reader MeCP2. Intriguingly, genes dysregulated in both Mecp2 null and domain-swap mice are implicated in other neurological disorders, potentially highlighting targets of relevance to the Rett syndrome phenotype.
Collapse
Affiliation(s)
- Rebekah Tillotson
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Justyna Cholewa-Waclaw
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kashyap Chhatbar
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - John C Connelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Sophie A Kirschner
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Shaun Webb
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Martha V Koerner
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Jim Selfridge
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - David A Kelly
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Dina De Sousa
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kyla Brown
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Matthew J Lyst
- Wellcome Centre for Cell Biology, University of Edinburgh, The Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Skirmantas Kriaucionis
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, 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
|
24
|
Connelly JC, Cholewa-Waclaw J, Webb S, Steccanella V, Waclaw B, Bird A. Absence of MeCP2 binding to non-methylated GT-rich sequences in vivo. Nucleic Acids Res 2020; 48:3542-3552. [PMID: 32064528 PMCID: PMC7144902 DOI: 10.1093/nar/gkaa102] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/18/2020] [Accepted: 02/13/2020] [Indexed: 12/16/2022] Open
Abstract
MeCP2 is a nuclear protein that binds to sites of cytosine methylation in the genome. While most evidence confirms this epigenetic mark as the primary determinant of DNA binding, MeCP2 is also reported to have an affinity for non-methylated DNA sequences. Here we investigated the molecular basis and in vivo significance of its reported affinity for non-methylated GT-rich sequences. We confirmed this interaction with isolated domains of MeCP2 in vitro and defined a minimal target DNA sequence. Binding depends on pyrimidine 5′ methyl groups provided by thymine and requires adjacent guanines and a correctly orientated A/T-rich flanking sequence. Unexpectedly, full-length MeCP2 protein failed to bind GT-rich sequences in vitro. To test for MeCP2 binding to these motifs in vivo, we analysed human neuronal cells using ChIP-seq and ATAC-seq technologies. While both methods robustly detected DNA methylation-dependent binding of MeCP2 to mCG and mCAC, neither showed evidence of MeCP2 binding to GT-rich motifs. The data suggest that GT binding is an in vitro phenomenon without in vivo relevance. Our findings argue that MeCP2 does not read unadorned DNA sequence and therefore support the notion that its primary role is to interpret epigenetic modifications of DNA.
Collapse
Affiliation(s)
- John C Connelly
- The Wellcome Centre for Cell Biology, University of Edinburgh, EH9 3BF Edinburgh, UK
| | | | - Shaun Webb
- The Wellcome Centre for Cell Biology, University of Edinburgh, EH9 3BF Edinburgh, UK
| | - Verdiana Steccanella
- The Wellcome Centre for Cell Biology, University of Edinburgh, EH9 3BF Edinburgh, UK
| | - Bartlomiej Waclaw
- School of Physics and Astronomy, University of Edinburgh, EH9 3FD Edinburgh, UK
| | - Adrian Bird
- The Wellcome Centre for Cell Biology, University of Edinburgh, EH9 3BF Edinburgh, UK
| |
Collapse
|
25
|
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
|