1
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Bui M, Baek S, Bentahar RS, Melters DP, Dalal Y. Native and tagged CENP-A histones are functionally inequivalent. Epigenetics Chromatin 2024; 17:19. [PMID: 38825690 PMCID: PMC11145777 DOI: 10.1186/s13072-024-00543-9] [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: 02/07/2024] [Accepted: 05/22/2024] [Indexed: 06/04/2024] Open
Abstract
BACKGROUND Over the past several decades, the use of biochemical and fluorescent tags has elucidated mechanistic and cytological processes that would otherwise be impossible. The challenging nature of certain nuclear proteins includes low abundancy, poor antibody recognition, and transient dynamics. One approach to get around those issues is the addition of a peptide or larger protein tag to the target protein to improve enrichment, purification, and visualization. However, many of these studies were done under the assumption that tagged proteins can fully recapitulate native protein function. RESULTS We report that when C-terminally TAP-tagged CENP-A histone variant is introduced, it undergoes altered kinetochore protein binding, differs in post-translational modifications (PTMs), utilizes histone chaperones that differ from that of native CENP-A, and can partially displace native CENP-A in human cells. Additionally, these tagged CENP-A-containing nucleosomes have reduced centromeric incorporation at early G1 phase and poorly associates with linker histone H1.5 compared to native CENP-A nucleosomes. CONCLUSIONS These data suggest expressing tagged versions of histone variant CENP-A may result in unexpected utilization of non-native pathways, thereby altering the biological function of the histone variant.
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Affiliation(s)
- Minh Bui
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, 41 Medlars Drive, Bldg 41/Rm B1300, Bethesda, MD, 20892, USA.
| | - Songjoon Baek
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, 41 Medlars Drive, Bldg 41/Rm B1300, Bethesda, MD, 20892, USA
| | - Reda S Bentahar
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, 41 Medlars Drive, Bldg 41/Rm B1300, Bethesda, MD, 20892, USA
| | - Daniël P Melters
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, 41 Medlars Drive, Bldg 41/Rm B1300, Bethesda, MD, 20892, USA
| | - Yamini Dalal
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, 41 Medlars Drive, Bldg 41/Rm B1300, Bethesda, MD, 20892, USA.
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2
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Packiaraj J, Thakur J. DNA satellite and chromatin organization at mouse centromeres and pericentromeres. Genome Biol 2024; 25:52. [PMID: 38378611 PMCID: PMC10880262 DOI: 10.1186/s13059-024-03184-z] [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: 06/02/2023] [Accepted: 02/12/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND Centromeres are essential for faithful chromosome segregation during mitosis and meiosis. However, the organization of satellite DNA and chromatin at mouse centromeres and pericentromeres is poorly understood due to the challenges of assembling repetitive genomic regions. RESULTS Using recently available PacBio long-read sequencing data from the C57BL/6 strain, we find that contrary to the previous reports of their homogeneous nature, both centromeric minor satellites and pericentromeric major satellites exhibit a high degree of variation in sequence and organization within and between arrays. While most arrays are continuous, a significant fraction is interspersed with non-satellite sequences, including transposable elements. Using chromatin immunoprecipitation sequencing (ChIP-seq), we find that the occupancy of CENP-A and H3K9me3 chromatin at centromeric and pericentric regions, respectively, is associated with increased sequence enrichment and homogeneity at these regions. The transposable elements at centromeric regions are not part of functional centromeres as they lack significant CENP-A enrichment. Furthermore, both CENP-A and H3K9me3 nucleosomes occupy minor and major satellites spanning centromeric-pericentric junctions and a low yet significant amount of CENP-A spreads locally at centromere junctions on both pericentric and telocentric sides. Finally, while H3K9me3 nucleosomes display a well-phased organization on major satellite arrays, CENP-A nucleosomes on minor satellite arrays are poorly phased. Interestingly, the homogeneous class of major satellites also phase CENP-A and H3K27me3 nucleosomes, indicating that the nucleosome phasing is an inherent property of homogeneous major satellites. CONCLUSIONS Our findings reveal that mouse centromeres and pericentromeres display a high diversity in satellite sequence, organization, and chromatin structure.
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Affiliation(s)
- Jenika Packiaraj
- Department of Biology, Emory University, 1510 Clifton Rd, Atlanta, GA, 30322, USA
| | - Jitendra Thakur
- Department of Biology, Emory University, 1510 Clifton Rd, Atlanta, GA, 30322, USA.
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3
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Melters DP, Neuman KC, Bentahar RS, Rakshit T, Dalal Y. Single molecule analysis of CENP-A chromatin by high-speed atomic force microscopy. eLife 2023; 12:e86709. [PMID: 37728600 PMCID: PMC10511241 DOI: 10.7554/elife.86709] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 09/01/2023] [Indexed: 09/21/2023] Open
Abstract
Chromatin accessibility is modulated in a variety of ways to create open and closed chromatin states, both of which are critical for eukaryotic gene regulation. At the single molecule level, how accessibility is regulated of the chromatin fiber composed of canonical or variant nucleosomes is a fundamental question in the field. Here, we developed a single-molecule tracking method where we could analyze thousands of canonical H3 and centromeric variant nucleosomes imaged by high-speed atomic force microscopy. This approach allowed us to investigate how changes in nucleosome dynamics in vitro inform us about transcriptional potential in vivo. By high-speed atomic force microscopy, we tracked chromatin dynamics in real time and determined the mean square displacement and diffusion constant for the variant centromeric CENP-A nucleosome. Furthermore, we found that an essential kinetochore protein CENP-C reduces the diffusion constant and mobility of centromeric nucleosomes along the chromatin fiber. We subsequently interrogated how CENP-C modulates CENP-A chromatin dynamics in vivo. Overexpressing CENP-C resulted in reduced centromeric transcription and impaired loading of new CENP-A molecules. From these data, we speculate that factors altering nucleosome mobility in vitro, also correspondingly alter transcription in vivo. Subsequently, we propose a model in which variant nucleosomes encode their own diffusion kinetics and mobility, and where binding partners can suppress or enhance nucleosome mobility.
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Affiliation(s)
- Daniël P Melters
- National Cancer Institute, Center for Cancer Research, Laboratory Receptor Biology and Gene ExpressionBethesdaUnited States
| | - Keir C Neuman
- National Heart, Lung, and Blood Institute, Laboratory of Single Molecule BiophysicsBethesdaUnited States
| | - Reda S Bentahar
- National Cancer Institute, Center for Cancer Research, Laboratory Receptor Biology and Gene ExpressionBethesdaUnited States
| | - Tatini Rakshit
- National Cancer Institute, Center for Cancer Research, Laboratory Receptor Biology and Gene ExpressionBethesdaUnited States
- Department of Chemistry, Shiv Nadar UniversityDadriIndia
| | - Yamini Dalal
- National Cancer Institute, Center for Cancer Research, Laboratory Receptor Biology and Gene ExpressionBethesdaUnited States
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4
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Packiaraj J, Thakur J. DNA satellite and chromatin organization at house mouse centromeres and pericentromeres. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.18.549612. [PMID: 37503200 PMCID: PMC10370071 DOI: 10.1101/2023.07.18.549612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Centromeres are essential for faithful chromosome segregation during mitosis and meiosis. However, the organization of satellite DNA and chromatin at mouse centromeres and pericentromeres is poorly understood due to the challenges of sequencing and assembling repetitive genomic regions. Using recently available PacBio long-read sequencing data from the C57BL/6 strain and chromatin profiling, we found that contrary to the previous reports of their highly homogeneous nature, centromeric and pericentromeric satellites display varied sequences and organization. We find that both centromeric minor satellites and pericentromeric major satellites exhibited sequence variations within and between arrays. While most arrays are continuous, a significant fraction is interspersed with non-satellite sequences, including transposable elements. Additionally, we investigated CENP-A and H3K9me3 chromatin organization at centromeres and pericentromeres using Chromatin immunoprecipitation sequencing (ChIP-seq). We found that the occupancy of CENP-A and H3K9me3 chromatin at centromeric and pericentric regions, respectively, is associated with increased sequence abundance and homogeneity at these regions. Furthermore, the transposable elements at centromeric regions are not part of functional centromeres as they lack CENP-A enrichment. Finally, we found that while H3K9me3 nucleosomes display a well-phased organization on major satellite arrays, CENP-A nucleosomes on minor satellite arrays lack phased organization. Interestingly, the homogeneous class of major satellites phase CENP-A and H3K27me3 nucleosomes as well, indicating that the nucleosome phasing is an inherent property of homogeneous major satellites. Overall, our findings reveal that house mouse centromeres and pericentromeres, which were previously thought to be highly homogenous, display significant diversity in satellite sequence, organization, and chromatin structure.
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Affiliation(s)
- Jenika Packiaraj
- Department of Biology, Emory University, 1510 Clifton Rd, Atlanta, GA 30322
| | - Jitendra Thakur
- Department of Biology, Emory University, 1510 Clifton Rd, Atlanta, GA 30322
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5
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Morrison O, Thakur J. Molecular Complexes at Euchromatin, Heterochromatin and Centromeric Chromatin. Int J Mol Sci 2021; 22:6922. [PMID: 34203193 PMCID: PMC8268097 DOI: 10.3390/ijms22136922] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 01/19/2023] Open
Abstract
Chromatin consists of a complex of DNA and histone proteins as its core components and plays an important role in both packaging DNA and regulating DNA metabolic pathways such as DNA replication, transcription, recombination, and chromosome segregation. Proper functioning of chromatin further involves a network of interactions among molecular complexes that modify chromatin structure and organization to affect the accessibility of DNA to transcription factors leading to the activation or repression of the transcription of target DNA loci. Based on its structure and compaction state, chromatin is categorized into euchromatin, heterochromatin, and centromeric chromatin. In this review, we discuss distinct chromatin factors and molecular complexes that constitute euchromatin-open chromatin structure associated with active transcription; heterochromatin-less accessible chromatin associated with silencing; centromeric chromatin-the site of spindle binding in chromosome segregation.
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Affiliation(s)
| | - Jitendra Thakur
- Department of Biology, Emory University, 1510 Clifton Rd #2006, Atlanta, GA 30322, USA;
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Bond KH, Fetting JL, Lary CW, Emery IF, Oxburgh L. FOXD1 regulates cell division in clear cell renal cell carcinoma. BMC Cancer 2021; 21:312. [PMID: 33761914 PMCID: PMC7988646 DOI: 10.1186/s12885-021-07957-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 02/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Forkhead transcription factors control cell growth in multiple cancer types. Foxd1 is essential for kidney development and mitochondrial metabolism, but its significance in renal cell carcinoma (ccRCC) has not been reported. METHODS Transcriptome data from the TCGA database was used to correlate FOXD1 expression with patient survival. FOXD1 was knocked out in the 786-O cell line and known targets were analyzed. Reduced cell growth was observed and investigated in vitro using growth rate and Seahorse XF metabolic assays and in vivo using a xenograft model. Cell cycle characteristics were determined by flow cytometry and immunoblotting. Immunostaining for TUNEL and γH2AX was used to measure DNA damage. Association of the FOXD1 pathway with cell cycle progression was investigated through correlation analysis using the TCGA database. RESULTS FOXD1 expression level in ccRCC correlated inversely with patient survival. Knockout of FOXD1 in 786-O cells altered expression of FOXD1 targets, particularly genes involved in metabolism (MICU1) and cell cycle progression. Investigation of metabolic state revealed significant alterations in mitochondrial metabolism and glycolysis, but no net change in energy production. In vitro growth rate assays showed a significant reduction in growth of 786-OFOXD1null. In vivo, xenografted 786-OFOXD1null showed reduced capacity for tumor formation and reduced tumor size. Cell cycle analysis showed that 786-OFOXD1null had an extended G2/M phase. Investigation of mitosis revealed a deficiency in phosphorylation of histone H3 in 786-OFOXD1null, and increased DNA damage. Genes correlate with FOXD1 in the TCGA dataset associate with several aspects of mitosis, including histone H3 phosphorylation. CONCLUSIONS We show that FOXD1 regulates the cell cycle in ccRCC cells by control of histone H3 phosphorylation, and that FOXD1 expression governs tumor formation and tumor growth. Transcriptome analysis supports this role for FOXD1 in ccRCC patient tumors and provides an explanation for the inverse correlation between tumor expression of FOXD1 and patient survival. Our findings reveal an important role for FOXD1 in maintaining chromatin stability and promoting cell cycle progression and provide a new tool with which to study the biology of FOXD1 in ccRCC.
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Affiliation(s)
- Kyle H Bond
- The Rogosin Institute, 310 East 67th Street, New York, NY, 10065, USA
- Graduate School of Biomedical Sciences and Engineering, University of Maine, 168 College Ave, Orono, 04469, ME, USA
| | - Jennifer L Fetting
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME, 04074, USA
- Current affiliation: ICON Plc, 2100 Pembrook Parkway, North Wales, 19446, PA, USA
| | - Christine W Lary
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME, 04074, USA
| | - Ivette F Emery
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME, 04074, USA
| | - Leif Oxburgh
- The Rogosin Institute, 310 East 67th Street, New York, NY, 10065, USA.
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7
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Melters DP, Dalal Y. Nano-Surveillance: Tracking Individual Molecules in a Sea of Chromatin. J Mol Biol 2020; 433:166720. [PMID: 33221335 PMCID: PMC8770095 DOI: 10.1016/j.jmb.2020.11.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/06/2020] [Accepted: 11/16/2020] [Indexed: 01/12/2023]
Abstract
Chromatin is the epigenomic platform for diverse nuclear processes such as DNA repair, replication, transcription, telomere, and centromere function. In cancer cells, mutations in key processes result in DNA amplification, chromosome translocations, and chromothripsis, severely distorting the natural chromatin state. In normal and diseased states, dozens of chromatin effectors alter the physical integrity and dynamics of chromatin at the level of both single nucleosomes and arrays of nucleosomes folded into 3-dimensional shapes. Integrating these length scales, from the 10 nm sized nucleosome to mitotic chromosomes, whilst jostling within the crowded environment of the cell, cannot yet be achieved by a single technology. In this review, we discuss tools that have proven powerful in the investigation of nucleosome and chromatin fiber dynamics. We also provide a deeper focus into atomic force microscopy (AFM) applications that can bridge diverse length and time scales. Using time course AFM, we observe that chromatin condensation by H1.5 is dynamic, whereas using nano-indentation force spectroscopy we observe that both histone variants and nucleosome binding partners alter material properties of individual nucleosomes. Finally, we demonstrate how high-speed AFM can visualize plasmid DNA dynamics, intermittent nucleosome-nucleosome contacts, and changes in nucleosome phasing along a contiguous chromatin fiber. Altogether, the development of innovative technologies holds the promise of revealing the secret lives of nucleosomes, potentially bridging the gaps in our understanding of how chromatin works within living cells and tissues.
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Affiliation(s)
- Daniël P Melters
- National Cancer Institute, Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, Bethesda, MD, United States.
| | - Yamini Dalal
- National Cancer Institute, Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, Bethesda, MD, United States.
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8
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Mitra S, Srinivasan B, Jansen LE. Stable inheritance of CENP-A chromatin: Inner strength versus dynamic control. J Cell Biol 2020; 219:e202005099. [PMID: 32931551 PMCID: PMC7659725 DOI: 10.1083/jcb.202005099] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/08/2020] [Accepted: 08/12/2020] [Indexed: 12/22/2022] Open
Abstract
Chromosome segregation during cell division is driven by mitotic spindle attachment to the centromere region on each chromosome. Centromeres form a protein scaffold defined by chromatin featuring CENP-A, a conserved histone H3 variant, in a manner largely independent of local DNA cis elements. CENP-A nucleosomes fulfill two essential criteria to epigenetically identify the centromere. They undergo self-templated duplication to reestablish centromeric chromatin following DNA replication. More importantly, CENP-A incorporated into centromeric chromatin is stably transmitted through consecutive cell division cycles. CENP-A nucleosomes have unique structural properties and binding partners that potentially explain their long lifetime in vivo. However, rather than a static building block, centromeric chromatin is dynamically regulated throughout the cell cycle, indicating that CENP-A stability is also controlled by external factors. We discuss recent insights and identify the outstanding questions on how dynamic control of the long-term stability of CENP-A ensures epigenetic centromere inheritance.
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Affiliation(s)
- Sreyoshi Mitra
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Bharath Srinivasan
- Mechanistic Biology and Profiling, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
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9
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Mahlke MA, Nechemia-Arbely Y. Guarding the Genome: CENP-A-Chromatin in Health and Cancer. Genes (Basel) 2020; 11:genes11070810. [PMID: 32708729 PMCID: PMC7397030 DOI: 10.3390/genes11070810] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/10/2020] [Accepted: 07/15/2020] [Indexed: 02/07/2023] Open
Abstract
Faithful chromosome segregation is essential for the maintenance of genomic integrity and requires functional centromeres. Centromeres are epigenetically defined by the histone H3 variant, centromere protein A (CENP-A). Here we highlight current knowledge regarding CENP-A-containing chromatin structure, specification of centromere identity, regulation of CENP-A deposition and possible contribution to cancer formation and/or progression. CENP-A overexpression is common among many cancers and predicts poor prognosis. Overexpression of CENP-A increases rates of CENP-A deposition ectopically at sites of high histone turnover, occluding CCCTC-binding factor (CTCF) binding. Ectopic CENP-A deposition leads to mitotic defects, centromere dysfunction and chromosomal instability (CIN), a hallmark of cancer. CENP-A overexpression is often accompanied by overexpression of its chaperone Holliday Junction Recognition Protein (HJURP), leading to epigenetic addiction in which increased levels of HJURP and CENP-A become necessary to support rapidly dividing p53 deficient cancer cells. Alterations in CENP-A posttranslational modifications are also linked to chromosome segregation errors and CIN. Collectively, CENP-A is pivotal to genomic stability through centromere maintenance, perturbation of which can lead to tumorigenesis.
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Affiliation(s)
- Megan A. Mahlke
- UPMC Hillman Cancer Center, Pittsburgh, PA 15213, USA;
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Yael Nechemia-Arbely
- UPMC Hillman Cancer Center, Pittsburgh, PA 15213, USA;
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Correspondence: ; Tel.: +1-412-623-3228; Fax: +1-412-623-7828
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10
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Melters DP, Pitman M, Rakshit T, Dimitriadis EK, Bui M, Papoian GA, Dalal Y. Intrinsic elasticity of nucleosomes is encoded by histone variants and calibrated by their binding partners. Proc Natl Acad Sci U S A 2019; 116:24066-24074. [PMID: 31712435 PMCID: PMC6883791 DOI: 10.1073/pnas.1911880116] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Histone variants fine-tune transcription, replication, DNA damage repair, and faithful chromosome segregation. Whether and how nucleosome variants encode unique mechanical properties to their cognate chromatin structures remains elusive. Here, using in silico and in vitro nanoindentation methods, extending to in vivo dissections, we report that histone variant nucleosomes are intrinsically more elastic than their canonical counterparts. Furthermore, binding proteins, which discriminate between histone variant nucleosomes, suppress this innate elasticity and also compact chromatin. Interestingly, when we overexpress the binding proteins in vivo, we also observe increased compaction of chromatin enriched for histone variant nucleosomes, correlating with diminished access. Taken together, these data suggest a plausible link between innate mechanical properties possessed by histone variant nucleosomes, the adaptability of chromatin states in vivo, and the epigenetic plasticity of the underlying locus.
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Affiliation(s)
- Daniël P Melters
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Mary Pitman
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
- Department of Chemistry and Biochemistry, Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742
| | - Tatini Rakshit
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Emilios K Dimitriadis
- Scanning Probe Microscopy Unit, Biomedical Engineering and Physical Science Shared Resource, National Institute for Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892
| | - Minh Bui
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Garegin A Papoian
- Department of Chemistry and Biochemistry, Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742;
| | - Yamini Dalal
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892;
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11
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Zhang W, Lukoyanova N, Miah S, Lucas J, Vaughan CK. Insights into Centromere DNA Bending Revealed by the Cryo-EM Structure of the Core Centromere Binding Factor 3 with Ndc10. Cell Rep 2018; 24:744-754. [PMID: 30021170 PMCID: PMC6077249 DOI: 10.1016/j.celrep.2018.06.068] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 05/06/2018] [Accepted: 06/15/2018] [Indexed: 12/21/2022] Open
Abstract
The centromere binding factor 3 (CBF3) complex binds the third centromere DNA element in organisms with point centromeres, such as S. cerevisiae. It is an essential complex for assembly of the kinetochore in these organisms, as it facilitates genetic centromere specification and allows association of all other kinetochore components. We determined high-resolution structures of the core complex of CBF3 alone and in association with a monomeric construct of Ndc10, using cryoelectron microscopy (cryo-EM). We identify the DNA-binding site of the complex and present a model in which CBF3 induces a tight bend in centromeric DNA, thus facilitating assembly of the centromeric nucleosome. Cryo-EM studies of CBF3 reveal the core complex has a deep asymmetric channel The size, conservation, and charge of the channel suggest that it binds centromere DNA Unique insertions in the Ctf13 F box provide the binding site for one Ndc10 monomer The Ndc10 DNA-binding site is in plane with and perpendicular to the CBF3 channel
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Affiliation(s)
- Wenjuan Zhang
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK; Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Natalya Lukoyanova
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Shomon Miah
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Jonathan Lucas
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Cara K Vaughan
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK; Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK.
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12
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Nechemia-Arbely Y, Fachinetti D, Miga KH, Sekulic N, Soni GV, Kim DH, Wong AK, Lee AY, Nguyen K, Dekker C, Ren B, Black BE, Cleveland DW. Human centromeric CENP-A chromatin is a homotypic, octameric nucleosome at all cell cycle points. J Cell Biol 2017; 216:607-621. [PMID: 28235947 PMCID: PMC5350519 DOI: 10.1083/jcb.201608083] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/18/2016] [Accepted: 01/17/2017] [Indexed: 12/11/2022] Open
Abstract
In this study, the authors use new reference models for 23 human centromeres and find that at all cell cycle phases centromeric CENP-A chromatin complexes are octameric nucleosomes with two molecules of CENP-A. This finding refutes previous models that have suggested that hemisomes may briefly transition to octameric nucleosomes. Chromatin assembled with centromere protein A (CENP-A) is the epigenetic mark of centromere identity. Using new reference models, we now identify sites of CENP-A and histone H3.1 binding within the megabase, α-satellite repeat–containing centromeres of 23 human chromosomes. The overwhelming majority (97%) of α-satellite DNA is found to be assembled with histone H3.1–containing nucleosomes with wrapped DNA termini. In both G1 and G2 cell cycle phases, the 2–4% of α-satellite assembled with CENP-A protects DNA lengths centered on 133 bp, consistent with octameric nucleosomes with DNA unwrapping at entry and exit. CENP-A chromatin is shown to contain equimolar amounts of CENP-A and histones H2A, H2B, and H4, with no H3. Solid-state nanopore analyses show it to be nucleosomal in size. Thus, in contrast to models for hemisomes that briefly transition to octameric nucleosomes at specific cell cycle points or heterotypic nucleosomes containing both CENP-A and histone H3, human CENP-A chromatin complexes are octameric nucleosomes with two molecules of CENP-A at all cell cycle phases.
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Affiliation(s)
- Yael Nechemia-Arbely
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Daniele Fachinetti
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Karen H Miga
- Center for Biomolecular Science and Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Nikolina Sekulic
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Gautam V Soni
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - Dong Hyun Kim
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Adeline K Wong
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Ah Young Lee
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Kristen Nguyen
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - Bing Ren
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Ben E Black
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Don W Cleveland
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
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13
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Ordu O, Lusser A, Dekker NH. Recent insights from in vitro single-molecule studies into nucleosome structure and dynamics. Biophys Rev 2016; 8:33-49. [PMID: 28058066 PMCID: PMC5167136 DOI: 10.1007/s12551-016-0212-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/17/2016] [Indexed: 01/04/2023] Open
Abstract
Eukaryotic DNA is tightly packed into a hierarchically ordered structure called chromatin in order to fit into the micron-scaled nucleus. The basic unit of chromatin is the nucleosome, which consists of a short piece of DNA wrapped around a core of eight histone proteins. In addition to their role in packaging DNA, nucleosomes impact the regulation of essential nuclear processes such as replication, transcription, and repair by controlling the accessibility of DNA. Thus, knowledge of this fundamental DNA-protein complex is crucial for understanding the mechanisms of gene control. While structural and biochemical studies over the past few decades have provided key insights into both the molecular composition and functional aspects of nucleosomes, these approaches necessarily average over large populations and times. In contrast, single-molecule methods are capable of revealing features of subpopulations and dynamic changes in the structure or function of biomolecules, rendering them a powerful complementary tool for probing mechanistic aspects of DNA-protein interactions. In this review, we highlight how these single-molecule approaches have recently yielded new insights into nucleosomal and subnucleosomal structures and dynamics.
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Affiliation(s)
- Orkide Ordu
- Bionanoscience Department, Kavli Institute of Nanoscience,, Delft University of Technology, Van der Maasweg 9,, 2629 HZ Delft, The Netherlands
| | - Alexandra Lusser
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Nynke H. Dekker
- Bionanoscience Department, Kavli Institute of Nanoscience,, Delft University of Technology, Van der Maasweg 9,, 2629 HZ Delft, The Netherlands
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14
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Thakur J, Henikoff S. CENPT bridges adjacent CENPA nucleosomes on young human α-satellite dimers. Genome Res 2016; 26:1178-87. [PMID: 27384170 PMCID: PMC5052034 DOI: 10.1101/gr.204784.116] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 06/29/2016] [Indexed: 12/15/2022]
Abstract
Nucleosomes containing the CenH3 (CENPA or CENP-A) histone variant replace H3 nucleosomes at centromeres to provide a foundation for kinetochore assembly. CENPA nucleosomes are part of the constitutive centromere associated network (CCAN) that forms the inner kinetochore on which outer kinetochore proteins assemble. Two components of the CCAN, CENPC and the histone-fold protein CENPT, provide independent connections from the ∼171-bp centromeric α-satellite repeat units to the outer kinetochore. However, the spatial relationship between CENPA nucleosomes and these two branches remains unclear. To address this issue, we use a base-pair resolution genomic readout of protein-protein interactions, comparative chromatin immunoprecipitation (ChIP) with sequencing, together with sequential ChIP, to infer the in vivo molecular architecture of the human CCAN. In contrast to the currently accepted model in which CENPT associates with H3 nucleosomes, we find that CENPT is centered over the CENPB box between two well-positioned CENPA nucleosomes on the most abundant centromeric young α-satellite dimers and interacts with the CENPB/CENPC complex. Upon cross-linking, the entire CENPA/CENPB/CENPC/CENPT complex is nuclease-protected over an α-satellite dimer that comprises the fundamental unit of centromeric chromatin. We conclude that CENPA/CENPC and CENPT pathways for kinetochore assembly are physically integrated over young α-satellite dimers.
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Affiliation(s)
- Jitendra Thakur
- Howard Hughes Medical Institute, Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Steven Henikoff
- Howard Hughes Medical Institute, Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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15
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Lunelli L, Bernabò P, Bolner A, Vaghi V, Marchioretto M, Viero G. Peering at Brain Polysomes with Atomic Force Microscopy. J Vis Exp 2016. [PMID: 27023752 DOI: 10.3791/53851] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The translational machinery, i.e., the polysome or polyribosome, is one of the biggest and most complex cytoplasmic machineries in cells. Polysomes, formed by ribosomes, mRNAs, several proteins and non-coding RNAs, represent integrated platforms where translational controls take place. However, while the ribosome has been widely studied, the organization of polysomes is still lacking comprehensive understanding. Thus much effort is required in order to elucidate polysome organization and any novel mechanism of translational control that may be embedded. Atomic force microscopy (AFM) is a type of scanning probe microscopy that allows the acquisition of 3D images at nanoscale resolution. Compared to electron microscopy (EM) techniques, one of the main advantages of AFM is that it can acquire thousands of images both in air and in solution, enabling the sample to be maintained under near physiological conditions without any need for staining and fixing procedures. Here, a detailed protocol for the accurate purification of polysomes from mouse brain and their deposition on mica substrates is described. This protocol enables polysome imaging in air and liquid with AFM and their reconstruction as three-dimensional objects. Complementary to cryo-electron microscopy (cryo-EM), the proposed method can be conveniently used for systematically analyzing polysomes and studying their organization.
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Affiliation(s)
- Lorenzo Lunelli
- Laboratory of Biomolecular Sequence and Structure Analysis for Health, Fondazione Bruno Kessler
| | | | | | - Valentina Vaghi
- Laboratory of Biomolecular Sequence and Structure Analysis for Health, Fondazione Bruno Kessler
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16
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Kaur P, Wu D, Lin J, Countryman P, Bradford KC, Erie DA, Riehn R, Opresko PL, Wang H. Enhanced electrostatic force microscopy reveals higher-order DNA looping mediated by the telomeric protein TRF2. Sci Rep 2016; 6:20513. [PMID: 26856421 PMCID: PMC4746636 DOI: 10.1038/srep20513] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 01/04/2016] [Indexed: 12/19/2022] Open
Abstract
Shelterin protein TRF2 modulates telomere structures by promoting dsDNA compaction and T-loop formation. Advancement of our understanding of the mechanism underlying TRF2-mediated DNA compaction requires additional information regarding DNA paths in TRF2-DNA complexes. To uncover the location of DNA inside protein-DNA complexes, we recently developed the Dual-Resonance-frequency-Enhanced Electrostatic force Microscopy (DREEM) imaging technique. DREEM imaging shows that in contrast to chromatin with DNA wrapping around histones, large TRF2-DNA complexes (with volumes larger than TRF2 tetramers) compact DNA inside TRF2 with portions of folded DNA appearing at the edge of these complexes. Supporting coarse-grained molecular dynamics simulations uncover the structural requirement and sequential steps during TRF2-mediated DNA compaction and result in folded DNA structures with protruding DNA loops as seen in DREEM imaging. Revealing DNA paths in TRF2 complexes provides new mechanistic insights into structure-function relationships underlying telomere maintenance pathways.
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Affiliation(s)
- Parminder Kaur
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Dong Wu
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Jiangguo Lin
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA.,School of Bioscience and Engineering, South China University of Technology, Guangzhou, Guangdong 510006, P.R. China
| | - Preston Countryman
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Kira C Bradford
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599
| | - Dorothy A Erie
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599.,Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, NC 27599
| | - Robert Riehn
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Patricia L Opresko
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania 15219, USA
| | - Hong Wang
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
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17
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Zhao H, Zhu X, Wang K, Gent JI, Zhang W, Dawe RK, Jiang J. Gene Expression and Chromatin Modifications Associated with Maize Centromeres. G3 (BETHESDA, MD.) 2015; 6:183-92. [PMID: 26564952 PMCID: PMC4704717 DOI: 10.1534/g3.115.022764] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 11/09/2015] [Indexed: 12/23/2022]
Abstract
Centromeres are defined by the presence of CENH3, a variant of histone H3. Centromeres in most plant species contain exclusively highly repetitive DNA sequences, which has hindered research on structure and function of centromeric chromatin. Several maize centromeres have been nearly completely sequenced, providing a sequence-based platform for genomic and epigenomic research of plant centromeres. Here we report a high resolution map of CENH3 nucleosomes in the maize genome. Although CENH3 nucleosomes are spaced ∼190 bp on average, CENH3 nucleosomes that occupied CentC, a 156-bp centromeric satellite repeat, showed clear positioning aligning with CentC monomers. Maize centromeres contain alternating CENH3-enriched and CENH3-depleted subdomains, which account for 87% and 13% of the centromeres, respectively. A number of annotated genes were identified in the centromeres, including 11 active genes that were located exclusively in CENH3-depleted subdomains. The euchromatic histone modification marks, including H3K4me3, H3K36me3 and H3K9ac, detected in maize centromeres were associated mainly with the active genes. Interestingly, maize centromeres also have lower levels of the heterochromatin histone modification mark H3K27me2 relative to pericentromeric regions. We conclude that neither H3K27me2 nor the three euchromatic histone modifications are likely to serve as functionally important epigenetic marks of centromere identity in maize.
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Affiliation(s)
- Hainan Zhao
- Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706
| | - Xiaobiao Zhu
- Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706
| | - Kai Wang
- Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706
| | - Jonathan I Gent
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602
| | - Wenli Zhang
- Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706
| | - R Kelly Dawe
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602
| | - Jiming Jiang
- Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706
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18
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Díaz-Ingelmo O, Martínez-García B, Segura J, Valdés A, Roca J. DNA Topology and Global Architecture of Point Centromeres. Cell Rep 2015; 13:667-677. [PMID: 26489472 DOI: 10.1016/j.celrep.2015.09.039] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 08/08/2015] [Accepted: 09/14/2015] [Indexed: 12/21/2022] Open
Abstract
DNA is wrapped in a left-handed fashion around histone octasomes containing the centromeric histone H3 variant CENP-A. However, DNA topology studies have suggested that DNA is wrapped in a right-handed manner around the CENP-A nucleosome that occupies the yeast point centromere. Here, we determine the DNA linking number difference (ΔLk) stabilized by the yeast centromere and the contribution of the centromere determining elements (CDEI, CDEII, and CDEIII). We show that the intrinsic architecture of the yeast centromere stabilizes +0.6 units of ΔLk. This topology depends on the integrity of CDEII and CDEIII, but it is independent of cbf1 binding to CDEI and of the variable length of CDEII. These findings suggest that the interaction of the CBF3 complex with CDEIII and a distal CDEII segment configures a right-handed DNA loop that excludes CDEI. This loop is then occupied by a CENP-A histone complex, which does not have to be inherently right-handed.
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Affiliation(s)
- Ofelia Díaz-Ingelmo
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona 08028, Spain
| | - Belén Martínez-García
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona 08028, Spain
| | - Joana Segura
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona 08028, Spain
| | - Antonio Valdés
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona 08028, Spain
| | - Joaquim Roca
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona 08028, Spain.
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19
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Fujita R, Otake K, Arimura Y, Horikoshi N, Miya Y, Shiga T, Osakabe A, Tachiwana H, Ohzeki JI, Larionov V, Masumoto H, Kurumizaka H. Stable complex formation of CENP-B with the CENP-A nucleosome. Nucleic Acids Res 2015; 43:4909-22. [PMID: 25916850 PMCID: PMC4446444 DOI: 10.1093/nar/gkv405] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 04/15/2015] [Indexed: 01/16/2023] Open
Abstract
CENP-A and CENP-B are major components of centromeric chromatin. CENP-A is the histone H3 variant, which forms the centromere-specific nucleosome. CENP-B specifically binds to the CENP-B box DNA sequence on the centromere-specific repetitive DNA. In the present study, we found that the CENP-A nucleosome more stably retains human CENP-B than the H3.1 nucleosome in vitro. Specifically, CENP-B forms a stable complex with the CENP-A nucleosome, when the CENP-B box sequence is located at the proximal edge of the nucleosome. Surprisingly, the CENP-B binding was weaker when the CENP-B box sequence was located in the distal linker region of the nucleosome. This difference in CENP-B binding, depending on the CENP-B box location, was not observed with the H3.1 nucleosome. Consistently, we found that the DNA-binding domain of CENP-B specifically interacted with the CENP-A-H4 complex, but not with the H3.1-H4 complex, in vitro. These results suggested that CENP-B forms a more stable complex with the CENP-A nucleosome through specific interactions with CENP-A, if the CENP-B box is located proximal to the CENP-A nucleosome. Our in vivo assay also revealed that CENP-B binding in the vicinity of the CENP-A nucleosome substantially stabilizes the CENP-A nucleosome on alphoid DNA in human cells.
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Affiliation(s)
- Risa Fujita
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Koichiro Otake
- Laboratory of Cell Engineering, Department of Frontier Research, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
| | - Yasuhiro Arimura
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Naoki Horikoshi
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Yuta Miya
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Tatsuya Shiga
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Akihisa Osakabe
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Hiroaki Tachiwana
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Jun-ichirou Ohzeki
- Laboratory of Cell Engineering, Department of Frontier Research, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
| | - Vladimir Larionov
- Development Therapeutic Branch, National Cancer Institute, National Institutes of Health, Building 37, Room 5040, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Hiroshi Masumoto
- Laboratory of Cell Engineering, Department of Frontier Research, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
| | - Hitoshi Kurumizaka
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
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20
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Abendroth C, Hofmeister A, Hake SB, Kamweru PK, Miess E, Dornblut C, Küffner I, Deng W, Leonhardt H, Orthaus S, Hoischen C, Diekmann S. The CENP-T C-terminus is exclusively proximal to H3.1 and not to H3.2 or H3.3. Int J Mol Sci 2015; 16:5839-63. [PMID: 25775162 PMCID: PMC4394509 DOI: 10.3390/ijms16035839] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 02/18/2015] [Accepted: 02/18/2015] [Indexed: 12/17/2022] Open
Abstract
The kinetochore proteins assemble onto centromeric chromatin and regulate DNA segregation during cell division. The inner kinetochore proteins bind centromeres while most outer kinetochore proteins assemble at centromeres during mitosis, connecting the complex to microtubules. The centromere-kinetochore complex contains specific nucleosomes and nucleosomal particles. CENP-A replaces canonical H3 in centromeric nucleosomes, defining centromeric chromatin. Next to CENP-A, the CCAN multi-protein complex settles which contains CENP-T/W/S/X. These four proteins are described to form a nucleosomal particle at centromeres. We had found the CENP-T C-terminus and the CENP-S termini next to histone H3.1 but not to CENP-A, suggesting that the Constitutive Centromere-Associated Network (CCAN) bridges a CENP-A- and a H3-containing nucleosome. Here, we show by in vivo FRET that this proximity between CENP-T and H3 is specific for H3.1 but neither for the H3.1 mutants H3.1(C96A) and H3.1(C110A) nor for H3.2 or H3.3. We also found CENP-M next to H3.1 but not to these H3.1 mutants. Consistently, we detected CENP-M next to CENP-S. These data elucidate the local molecular neighborhood of CCAN proteins next to a H3.1-containing centromeric nucleosome. They also indicate an exclusive position of H3.1 clearly distinct from H3.2, thus documenting a local, and potentially also functional, difference between H3.1 and H3.2.
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Affiliation(s)
- Christian Abendroth
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Antje Hofmeister
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Sandra B Hake
- Department of Molecular Biology, Center for Integrated Protein Science Munich (CIPSM), Adolf-Butenandt-Institute, Ludwig-Maximilians-Universität Munich, Schillerstr. 44, D-80336 Munich, Germany.
| | - Paul K Kamweru
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Elke Miess
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Carsten Dornblut
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Isabell Küffner
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Wen Deng
- Department of Biology II, Center for Integrated Protein Science, Ludwig-Maximilians-Universität Munich, Planegg-Martinsried, D-82152 Munich, Germany.
| | - Heinrich Leonhardt
- Department of Biology II, Center for Integrated Protein Science, Ludwig-Maximilians-Universität Munich, Planegg-Martinsried, D-82152 Munich, Germany.
| | | | - Christian Hoischen
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Stephan Diekmann
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
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21
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Athwal RK, Walkiewicz MP, Baek S, Fu S, Bui M, Camps J, Ried T, Sung MH, Dalal Y. CENP-A nucleosomes localize to transcription factor hotspots and subtelomeric sites in human cancer cells. Epigenetics Chromatin 2015; 8:2. [PMID: 25788983 PMCID: PMC4363203 DOI: 10.1186/1756-8935-8-2] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 12/01/2014] [Indexed: 12/21/2022] Open
Abstract
Background The histone H3 variant CENP-A is normally tightly regulated to ensure only one centromere exists per chromosome. Native CENP-A is often found overexpressed in human cancer cells and a range of human tumors. Consequently, CENP-A misregulation is thought to contribute to genome instability in human cancers. However, the consequences of such overexpression have not been directly elucidated in human cancer cells. Results To investigate native CENP-A overexpression, we sought to uncover CENP-A-associated defects in human cells. We confirm that CENP-A is innately overexpressed in several colorectal cancer cell lines. In such cells, we report that a subset of structurally distinct CENP-A-containing nucleosomes associate with canonical histone H3, and with the transcription-coupled chaperones ATRX and DAXX. Furthermore, such hybrid CENP-A nucleosomes localize to DNase I hypersensitive and transcription factor binding sites, including at promoters of genes across the human genome. A distinct class of CENP-A hotspots also accumulates at subtelomeric chromosomal locations, including at the 8q24/Myc region long-associated with genomic instability. We show this 8q24 accumulation of CENP-A can also be seen in early stage primary colorectal tumors. Conclusions Our data demonstrate that excess CENP-A accumulates at noncentromeric locations in the human cancer genome. These findings suggest that ectopic CENP-A nucleosomes could alter the state of the chromatin fiber, potentially impacting gene regulation and chromosome fragility. Electronic supplementary material The online version of this article (doi:10.1186/1756-8935-8-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rajbir K Athwal
- Chromatin Structure and Epigenetics Mechanisms Unit, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA ; Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA
| | - Marcin P Walkiewicz
- Chromatin Structure and Epigenetics Mechanisms Unit, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA ; Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA
| | - Songjoon Baek
- Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA
| | - Song Fu
- Chromatin Structure and Epigenetics Mechanisms Unit, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA ; Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA
| | - Minh Bui
- Chromatin Structure and Epigenetics Mechanisms Unit, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA ; Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA
| | - Jordi Camps
- Genetics Branch, Center for Cancer Research, National Cancer Institute National Institutes of Health, 50 South Drive, Bethesda, MD 20892 USA
| | - Thomas Ried
- Genetics Branch, Center for Cancer Research, National Cancer Institute National Institutes of Health, 50 South Drive, Bethesda, MD 20892 USA
| | - Myong-Hee Sung
- Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA
| | - Yamini Dalal
- Chromatin Structure and Epigenetics Mechanisms Unit, Center for Cancer Research, National Cancer Institute National Institutes of Health, 41 Center Drive, Bethesda, MD 20892 USA
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22
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Westhorpe FG, Straight AF. The centromere: epigenetic control of chromosome segregation during mitosis. Cold Spring Harb Perspect Biol 2014; 7:a015818. [PMID: 25414369 DOI: 10.1101/cshperspect.a015818] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A fundamental challenge for the survival of all organisms is maintaining the integrity of the genome in all cells. Cells must therefore segregate their replicated genome equally during each cell division. Eukaryotic organisms package their genome into a number of physically distinct chromosomes, which replicate during S phase and condense during prophase of mitosis to form paired sister chromatids. During mitosis, cells form a physical connection between each sister chromatid and microtubules of the mitotic spindle, which segregate one copy of each chromatid to each new daughter cell. The centromere is the DNA locus on each chromosome that creates the site of this connection. In this review, we present a brief history of centromere research and discuss our current knowledge of centromere establishment, maintenance, composition, structure, and function in mitosis.
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Affiliation(s)
- Frederick G Westhorpe
- Department of Biochemistry, Stanford University Medical School, Stanford, California 94305
| | - Aaron F Straight
- Department of Biochemistry, Stanford University Medical School, Stanford, California 94305
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23
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Abstract
Since discovery of the centromere-specific histone H3 variant CENP-A, centromeres have come to be defined as chromatin structures that establish the assembly site for the complex kinetochore machinery. In most organisms, centromere activity is defined epigenetically, rather than by specific DNA sequences. In this review, we describe selected classic work and recent progress in studies of centromeric chromatin with a focus on vertebrates. We consider possible roles for repetitive DNA sequences found at most centromeres, chromatin factors and modifications that assemble and activate CENP-A chromatin for kinetochore assembly, plus the use of artificial chromosomes and kinetochores to study centromere function.
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Affiliation(s)
- Tatsuo Fukagawa
- Department of Molecular Genetics, National Institute of Genetics and Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka 411-8540, Japan.
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh, EH9 3JR, UK.
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24
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Biterge B, Schneider R. Histone variants: key players of chromatin. Cell Tissue Res 2014; 356:457-66. [PMID: 24781148 DOI: 10.1007/s00441-014-1862-4] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 02/27/2014] [Indexed: 01/01/2023]
Abstract
Histones are fundamental structural components of chromatin. Eukaryotic DNA is wound around an octamer of the core histones H2A, H2B, H3, and H4. Binding of linker histone H1 promotes higher order chromatin organization. In addition to their structural role, histones impact chromatin function and dynamics by, e.g., post-translational histone modifications or the presence of specific histone variants. Histone variants exhibit differential expression timings (DNA replication-independent) and mRNA characteristics compared to canonical histones. Replacement of canonical histones with histone variants can affect nucleosome stability and help to create functionally distinct chromatin domains. In line with this, several histone variants have been implicated in the regulation of cellular processes such as DNA repair and transcriptional activity. In this review, we focus on recent progress in the study of core histone variants H2A.X, H2A.Z, macroH2A, H3.3, and CENP-A, as well as linker histone H1 variants, their functions and their links to development and disease.
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Affiliation(s)
- Burcu Biterge
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR 7104, INSERM U 964, Université de Strasbourg, 67404, Illkirch, France
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25
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Reply to "CENP-A octamers do not confer a reduction in nucleosome height by AFM". Nat Struct Mol Biol 2014; 21:5-8. [PMID: 24389543 DOI: 10.1038/nsmb.2744] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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26
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Codomo CA, Furuyama T, Henikoff S. CENP-A octamers do not confer a reduction in nucleosome height by AFM. Nat Struct Mol Biol 2014; 21:4-5. [PMID: 24389542 DOI: 10.1038/nsmb.2743] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Christine A Codomo
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Takehito Furuyama
- 1] Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA. [2] Howard Hughes Medical Institute, Seattle, Washington, USA
| | - Steven Henikoff
- 1] Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA. [2] Howard Hughes Medical Institute, Seattle, Washington, USA
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27
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A network of players in H3 histone variant deposition and maintenance at centromeres. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:241-50. [DOI: 10.1016/j.bbagrm.2013.11.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 11/14/2013] [Accepted: 11/19/2013] [Indexed: 11/21/2022]
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Hamiche A, Shuaib M. Chaperoning the histone H3 family. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1819:230-237. [PMID: 24459725 DOI: 10.1016/j.bbagrm.2011.08.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Chromatin is a highly dynamic nucleoprotein structure, which orchestrates all nuclear process from DNA replication to DNA repair, fromtranscription to recombination. The proper in vivo assembly of nucleosome, the basic repeating unit of chromatin, requires the deposition of two H3-H4 dimer pairs followed by the addition of two dimers of H2A and H2B. Histone chaperones are responsible for delivery of histones to the site of chromatin assembly and histone deposition onto DNA, histone exchange and removal. Distinct factors have been found associated with different histone H3 variants, which facilitate their deposition. Unraveling the mechanism of histone depositionby specific chaperones is of key importance to epigenetic regulation. In this review, we focus on histoneH3 variants and their deposition mechanisms. This article is part of a Special Issue entitled: Histone chaperones and Chromatin assembly.
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29
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Abstract
The propagation of all organisms depends on the accurate and orderly segregation of chromosomes in mitosis and meiosis. Budding yeast has long served as an outstanding model organism to identify the components and underlying mechanisms that regulate chromosome segregation. This review focuses on the kinetochore, the macromolecular protein complex that assembles on centromeric chromatin and maintains persistent load-bearing attachments to the dynamic tips of spindle microtubules. The kinetochore also serves as a regulatory hub for the spindle checkpoint, ensuring that cell cycle progression is coupled to the achievement of proper microtubule-kinetochore attachments. Progress in understanding the composition and overall architecture of the kinetochore, as well as its properties in making and regulating microtubule attachments and the spindle checkpoint, is discussed.
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30
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Geiss CP, Keramisanou D, Sekulic N, Scheffer MP, Black BE, Frangakis AS. CENP-A arrays are more condensed than canonical arrays at low ionic strength. Biophys J 2014; 106:875-82. [PMID: 24559990 PMCID: PMC3944588 DOI: 10.1016/j.bpj.2014.01.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/02/2014] [Accepted: 01/07/2014] [Indexed: 10/25/2022] Open
Abstract
The centromeric histone H3 variant centromeric protein A (CENP-A), whose sequence is the least conserved among all histone variants, is responsible for specifying the location of the centromere. Here, we present a comprehensive study of CENP-A nucleosome arrays by cryo-electron tomography. We see that CENP-A arrays have different biophysical properties than canonical ones under low ionic conditions, as they are more condensed with a 20% smaller average nearest-neighbor distance and a 30% higher nucleosome density. We find that CENP-A nucleosomes have a predominantly crossed DNA entry/exit site that is narrowed on average by 8°, and they have a propensity to stack face to face. We therefore propose that CENP-A induces geometric constraints at the nucleosome DNA entry/exit site to bring neighboring nucleosomes into close proximity. This specific property of CENP-A may be responsible for generating a fundamental process that contributes to increased chromatin fiber compaction that is propagated under physiological conditions to form centromeric chromatin.
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Affiliation(s)
| | | | - Nikolina Sekulic
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Ben E Black
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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31
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Walkiewicz MP, Bui M, Quénet D, Dalal Y. Tracking histone variant nucleosomes across the human cell cycle using biophysical, biochemical, and cytological analyses. Methods Mol Biol 2014; 1170:589-615. [PMID: 24906339 PMCID: PMC6322406 DOI: 10.1007/978-1-4939-0888-2_34] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Histone variants such as H3.3, macroH2A, H2A.Z, and CENP-A are important epigenetic modifiers of the chromatin state in eukaryotic genomes. The centromeric histone H3 variant CENP-A/CENH3 epigenetically marks centromeres and is required for assembly of the kinetochore complex, a region of the chromosome that is responsible for proper genome segregation during mitosis. Several diverse techniques using biochemical, cell biology, and biophysical approaches have been utilized to study the nature of the CENP-A nucleosome across the cell cycle. In this chapter, we describe methods for CENP-A nucleosome purification and separation of CENP-A from other core histones using traditional SDS-PAGE and more resolving techniques such as Triton acid urea (TAU) and two-dimensional gels. We also discuss methods for observation of CENP-A on chromatin fibers using immunofluorescence. Finally, we provide a detailed description of analysis of chromatin structures using atomic force microscopy.
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Affiliation(s)
- Marcin P Walkiewicz
- Chromatin Structure and Epigenetic Mechanisms Unit, Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
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Walkiewicz MP, Dimitriadis EK, Dalal Y. CENP-A octamers do not confer a reduction in nucleosome height by AFM. Nat Struct Mol Biol 2014; 21:2-3. [PMID: 24389541 PMCID: PMC6756849 DOI: 10.1038/nsmb.2742] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Marcin P Walkiewicz
- National Cancer Institute, National Institutes of Health,
Bethesda Maryland, USA
| | - Emilios K Dimitriadis
- National Institute for BioImaging and BioEngineering,
National Institutes of Health, Bethesda, Maryland, USA
| | - Yamini Dalal
- National Cancer Institute, National Institutes of Health,
Bethesda Maryland, USA
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33
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Hwang YJ, Han D, Kim KY, Min SJ, Kowall NW, Yang L, Lee J, Kim Y, Ryu H. ESET methylates UBF at K232/254 and regulates nucleolar heterochromatin plasticity and rDNA transcription. Nucleic Acids Res 2013; 42:1628-43. [PMID: 24234436 PMCID: PMC3919562 DOI: 10.1093/nar/gkt1041] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The remodeling of chromatin in the nucleolus is important for the control of ribosomal DNA (rDNA) transcription and ribosome biogenesis. Herein, we found that upstream binding factor (UBF) interacts with ESET, a histone H3K9 methyltransferase and is trimethylated at Lys (K) 232/254 by ESET. UBF trimethylation leads to nucleolar chromatin condensation and decreased rDNA transcriptional activity. UBF mutations at K232/254A and K232/254R restored rDNA transcriptional activity in response to ESET. Both ESET-ΔSET mutant and knockdown of ESET by short hairpin RNA reduced trimethylation of UBF and resulted in the restoration of rDNA transcription. Atomic force microscopy confirmed that UBF trimethylated by ESET modulates the plasticity of nucleolar chromatin. We further demonstrated that UBF trimethylation at K232/254 by ESET deregulates rDNA transcription in a cell model of Huntington’s disease. Together, our findings show that a novel epigenetic modification of UBF is linked to impaired rDNA transcription and nucleolar chromatin remodeling, which may play key roles in the pathogenesis of neurodegeneration.
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Affiliation(s)
- Yu Jin Hwang
- Department of Biomedical Sciences, World Class University Neurocytomics Group, Seoul National University College of Medicine, Seoul 110-799, South Korea, Medical Engineering, Seoul National University College of Medicine, Seoul 110-799, South Korea, Center for Neuro-Medicine, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea, VA Boston Healthcare System, Boston, MA 02130, USA, Boston University Alzheimer's Disease Center and Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA, Department of Orthopedics and Division of Hematology, University of Washington School of Medicine, Seattle, WA 98195, USA and Medical Research Service, VA Puget Sound Health Care System, Seattle, WA 98108, USA
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34
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Catania S, Allshire RC. Anarchic centromeres: deciphering order from apparent chaos. Curr Opin Cell Biol 2013; 26:41-50. [PMID: 24529245 PMCID: PMC3978670 DOI: 10.1016/j.ceb.2013.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 09/20/2013] [Accepted: 09/24/2013] [Indexed: 12/16/2022]
Abstract
Specialised chromatin in which canonical histone H3 is replaced by CENP-A, an H3 related protein, is a signature of active centromeres and provides the foundation for kinetochore assembly. The location of centromeres is not fixed since centromeres can be inactivated and new centromeres can arise at novel locations independently of specific DNA sequence elements. Therefore, the establishment and maintenance of CENP-A chromatin and kinetochores provide an exquisite example of genuine epigenetic regulation. The composition of CENP-A nucleosomes is contentious but several studies suggest that, like regular H3 particles, they are octamers. Recent analyses have provided insight into how CENP-A is recognised and propagated, identified roles for post-translational modifications and dissected how CENP-A recruits other centromere proteins to mediate kinetochore assembly.
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Affiliation(s)
- Sandra Catania
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, 6.34 Swann Building, Mayfield Road, Edinburgh EH9 3JR, Scotland, UK
| | - Robin C Allshire
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, 6.34 Swann Building, Mayfield Road, Edinburgh EH9 3JR, Scotland, UK.
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35
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Topological similarity between the 2μm plasmid partitioning locus and the budding yeast centromere: evidence for a common evolutionary origin? Biochem Soc Trans 2013; 41:501-7. [PMID: 23514143 DOI: 10.1042/bst20120224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The partitioning locus STB of the selfish plasmid, the 2μm circle, of Saccharomyces cerevisiae is essential for the propagation of this multi-copy extra-chromosomal DNA element with nearly chromosome-like stability. The functional competence of STB requires the plasmid-coded partitioning proteins Rep1 and Rep2 as well as host-coded proteins. Host factors that associate with STB in a Rep1- and Rep2-dependent manner also interact with centromeres, and play important roles in chromosome segregation. They include the cohesin complex and the centromere-specific histone H3 variant Cse4. The genetically defined point centromere of S. cerevisiae differs starkly from the much more widespread epigenetically specified regional centromeres of eukaryotes. The particularly small size of the S. cerevisiae centromere and the association of chromosome segregation factors with STB raise the possibility of an evolutionary link between these two partitioning loci. The unusual positive supercoiling harboured by the S. cerevisiae centromere and STB in vivo in their functional states, unveiled by recent experiments, bolsters the notion of their potential descent from an ancestral plasmid partitioning locus.
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36
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A two-step mechanism for epigenetic specification of centromere identity and function. Nat Cell Biol 2013; 15:1056-66. [PMID: 23873148 DOI: 10.1038/ncb2805] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 06/11/2013] [Indexed: 02/06/2023]
Abstract
The basic determinant of chromosome inheritance, the centromere, is specified in many eukaryotes by an epigenetic mark. Using gene targeting in human cells and fission yeast, chromatin containing the centromere-specific histone H3 variant CENP-A is demonstrated to be the epigenetic mark that acts through a two-step mechanism to identify, maintain and propagate centromere function indefinitely. Initially, centromere position is replicated and maintained by chromatin assembled with the centromere-targeting domain (CATD) of CENP-A substituted into H3. Subsequently, nucleation of kinetochore assembly onto CATD-containing chromatin is shown to require either the amino- or carboxy-terminal tail of CENP-A for recruitment of inner kinetochore proteins, including stabilizing CENP-B binding to human centromeres or direct recruitment of CENP-C, respectively.
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37
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38
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Miell MDD, Fuller CJ, Guse A, Barysz HM, Downes A, Owen-Hughes T, Rappsilber J, Straight AF, Allshire RC. CENP-A confers a reduction in height on octameric nucleosomes. Nat Struct Mol Biol 2013; 20:763-5. [PMID: 23644598 PMCID: PMC3676451 DOI: 10.1038/nsmb.2574] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/03/2013] [Indexed: 02/05/2023]
Abstract
Nucleosomes with histone H3 replaced by CENP-A direct kinetochore assembly. CENP-A nucleosomes from human and Drosophila have been reported to have reduced heights as compared to canonical octameric H3 nucleosomes, thus suggesting a unique tetrameric hemisomal composition. We demonstrate that octameric CENP-A nucleosomes assembled in vitro exhibit reduced heights, indicating that they are physically distinct from H3 nucleosomes and negating the need to invoke the presence of hemisomes.
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Affiliation(s)
- Matthew D D Miell
- Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, UK
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39
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Vardabasso C, Hasson D, Ratnakumar K, Chung CY, Duarte LF, Bernstein E. Histone variants: emerging players in cancer biology. Cell Mol Life Sci 2013; 71:379-404. [PMID: 23652611 DOI: 10.1007/s00018-013-1343-z] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 04/09/2013] [Accepted: 04/11/2013] [Indexed: 01/01/2023]
Abstract
Histone variants are key players in shaping chromatin structure, and, thus, in regulating fundamental cellular processes such as chromosome segregation and gene expression. Emerging evidence points towards a role for histone variants in contributing to tumor progression, and, recently, the first cancer-associated mutation in a histone variant-encoding gene was reported. In addition, genetic alterations of the histone chaperones that specifically regulate chromatin incorporation of histone variants are rapidly being uncovered in numerous cancers. Collectively, these findings implicate histone variants as potential drivers of cancer initiation and/or progression, and, therefore, targeting histone deposition or the chromatin remodeling machinery may be of therapeutic value. Here, we review the mammalian histone variants of the H2A and H3 families in their respective cellular functions, and their involvement in tumor biology.
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Affiliation(s)
- Chiara Vardabasso
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY, 10029, USA
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40
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Padeganeh A, Ryan J, Boisvert J, Ladouceur AM, Dorn J, Maddox P. Octameric CENP-A Nucleosomes Are Present at Human Centromeres throughout the Cell Cycle. Curr Biol 2013; 23:764-9. [DOI: 10.1016/j.cub.2013.03.037] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/26/2013] [Accepted: 03/13/2013] [Indexed: 11/17/2022]
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41
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Furuyama T, Codomo CA, Henikoff S. Reconstitution of hemisomes on budding yeast centromeric DNA. Nucleic Acids Res 2013; 41:5769-83. [PMID: 23620291 PMCID: PMC3675498 DOI: 10.1093/nar/gkt314] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The structure of nucleosomes that contain the cenH3 histone variant has been controversial. In budding yeast, a single right-handed cenH3/H4/H2A/H2B tetramer wraps the ∼80-bp Centromere DNA Element II (CDE II) sequence of each centromere into a ‘hemisome’. However, attempts to reconstitute cenH3 particles in vitro have yielded exclusively ‘octasomes’, which are observed in vivo on chromosome arms only when Cse4 (yeast cenH3) is overproduced. Here, we show that Cse4 octamers remain intact under conditions of low salt and urea that dissociate H3 octamers. However, particles consisting of two DNA duplexes wrapped around a Cse4 octamer and separated by a gap efficiently split into hemisomes. Hemisome dimensions were confirmed using a calibrated gel-shift assay and atomic force microscopy, and their identity as tightly wrapped particles was demonstrated by gelFRET. Surprisingly, Cse4 hemisomes were stable in 4 M urea. Stable Cse4 hemisomes could be reconstituted using either full-length or tailless histones and with a 78-bp CDEII segment, which is predicted to be exceptionally stiff. We propose that CDEII DNA stiffness evolved to favor Cse4 hemisome over octasome formation. The precise correspondence between Cse4 hemisomes resident on CDEII in vivo and reconstituted on CDEII in vitro without any other factors implies that CDEII is sufficient for hemisome assembly.
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Affiliation(s)
- Takehito Furuyama
- Howard Hughes Medical Institute and Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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42
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Norman-Axelsson U, Durand-Dubief M, Prasad P, Ekwall K. DNA topoisomerase III localizes to centromeres and affects centromeric CENP-A levels in fission yeast. PLoS Genet 2013; 9:e1003371. [PMID: 23516381 PMCID: PMC3597498 DOI: 10.1371/journal.pgen.1003371] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 01/25/2013] [Indexed: 11/21/2022] Open
Abstract
Centromeres are specialized chromatin regions marked by the presence of nucleosomes containing the centromere-specific histone H3 variant CENP-A, which is essential for chromosome segregation. Assembly and disassembly of nucleosomes is intimately linked to DNA topology, and DNA topoisomerases have previously been implicated in the dynamics of canonical H3 nucleosomes. Here we show that Schizosaccharomyces pombe Top3 and its partner Rqh1 are involved in controlling the levels of CENP-ACnp1 at centromeres. Both top3 and rqh1 mutants display defects in chromosome segregation. Using chromatin immunoprecipitation and tiling microarrays, we show that Top3, unlike Top1 and Top2, is highly enriched at centromeric central domains, demonstrating that Top3 is the major topoisomerase in this region. Moreover, centromeric Top3 occupancy positively correlates with CENP-ACnp1 occupancy. Intriguingly, both top3 and rqh1 mutants display increased relative enrichment of CENP-ACnp1 at centromeric central domains. Thus, Top3 and Rqh1 normally limit the levels of CENP-ACnp1 in this region. This new role is independent of the established function of Top3 and Rqh1 in homologous recombination downstream of Rad51. Therefore, we hypothesize that the Top3-Rqh1 complex has an important role in controlling centromere DNA topology, which in turn affects the dynamics of CENP-ACnp1 nucleosomes. Centromeres are unique regions on eukaryotic chromosomes that are essential for chromosome segregation at mitosis and meiosis. Centromere identity and function depends on the presence of specialized chromatin with nucleosomes containing the centromere-specific histone H3 variant CENP-A. Assembly and disassembly of nucleosomes have previously been shown to involve a family of enzymes known as DNA topoisomerases. We show that centromeres are unique in that they are associated with high levels of Top3, but low levels of Top1 and Top2, suggesting that Top3 is particularly important for centromeric DNA topology. Impaired function of Top3 or its partner Rqh1 results in chromosome segregation defects and increased levels of CENP-ACnp1 at centromeres. This role in limiting the levels of CENP-ACnp1 at centromeres is independent of the established role for the Top3-Rqh1 complex in homologous recombination. Therefore, we hypothesize that the Top3-Rqh1 complex exerts this effect by regulating centromere DNA topology, which in turn affects CENP-ACnp1 nucleosome dynamics. Specific removal of negative supercoiling by Top3 could directly have a negative effect on assembly of CENP-ACnp1 nucleosomes with left-handed negative wrapping of DNA and/or act indirectly by inhibiting transcription-coupled CENP-ACnp1 assembly. Alternatively, Top3 may be a factor that promotes formation of CENP-ACnp1 hemisomes with right-handed wrapping of DNA over conventional octamers. This suggests a new role for the Top3-Rqh1 complex at centromeres and may contribute to the understanding of the structural and functional specification of centromeres.
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Affiliation(s)
- Ulrika Norman-Axelsson
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Mickaël Durand-Dubief
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Punit Prasad
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Karl Ekwall
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
- * E-mail:
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43
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Padeganeh A, De Rop V, Maddox PS. Nucleosomal composition at the centromere: a numbers game. Chromosome Res 2013; 21:27-36. [PMID: 23328870 PMCID: PMC3601254 DOI: 10.1007/s10577-012-9335-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 11/27/2012] [Accepted: 12/27/2012] [Indexed: 12/01/2022]
Abstract
The Centromere is a unique chromosomal locus where the kinetochore is formed to mediate faithful chromosome partitioning, thus maintaining ploidy during cell division. Centromere identity is inherited via an epigenetic mechanism involving a histone H3 variant, called centromere protein A (CENP-A) which replaces H3 in centromeric chromatin. In spite of extensive efforts in field of centromere biology during the past decade, controversy persists over the structural nature of the CENP-A-containing epigenetic mark, both at nucleosomal and chromatin levels. Here, we review recent findings and hypotheses regarding the structure of CENP-A-containing complexes.
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Affiliation(s)
- Abbas Padeganeh
- Institute for Research in Immunology and Cancer (IRIC), University of Montreal, Montreal, H3T1J4, QC, Canada
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44
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Tachiwana H, Miya Y, Shono N, Ohzeki JI, Osakabe A, Otake K, Larionov V, Earnshaw WC, Kimura H, Masumoto H, Kurumizaka H. Nap1 regulates proper CENP-B binding to nucleosomes. Nucleic Acids Res 2013; 41:2869-80. [PMID: 23325853 PMCID: PMC3597661 DOI: 10.1093/nar/gks1464] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
CENP-B is a widely conserved centromeric satellite DNA-binding protein, which specifically binds to a 17-bp DNA sequence known as the CENP-B box. CENP-B functions positively in the de novo assembly of centromeric nucleosomes, containing the centromere-specific histone H3 variant, CENP-A. At the same time, CENP-B also prevents undesired assembly of the CENP-A nucleosome through heterochromatin formation on satellite DNA integrated into ectopic sites. Therefore, improper CENP-B binding to chromosomes could be harmful. However, no CENP-B eviction mechanism has yet been reported. In the present study, we found that human Nap1, an acidic histone chaperone, inhibited the non-specific binding of CENP-B to nucleosomes and apparently stimulated CENP-B binding to its cognate CENP-B box DNA in nucleosomes. In human cells, the CENP-B eviction activity of Nap1 was confirmed in model experiments, in which the CENP-B binding to a human artificial chromosome or an ectopic chromosome locus bearing CENP-B boxes was significantly decreased when Nap1 was tethered near the CENP-B box sequence. In contrast, another acidic histone chaperone, sNASP, did not promote CENP-B eviction in vitro and in vivo and did not stimulate specific CENP-B binding to CENP-A nucleosomes in vitro. We therefore propose a novel mechanism of CENP-B regulation by Nap1.
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Affiliation(s)
- Hiroaki Tachiwana
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
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Bui M, Walkiewicz MP, Dimitriadis EK, Dalal Y. The CENP-A nucleosome: a battle between Dr Jekyll and Mr Hyde. Nucleus 2013; 4:37-42. [PMID: 23324462 PMCID: PMC3585026 DOI: 10.4161/nucl.23588] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The structure of the centromere-specific histone centromeric protein A (CENP-A) nucleosome has been a hot topic of debate for the past five years. Structures proposed include octamers, hexamers, homotypic and heterotypic tetramers. This controversy has led to the proposal that CENP-A nucleosomes undergo cell-cycle dependent transitions between the multiple states previously documented to exist in vivo and in vitro. In recent work from our laboratory, we sought to test this hypothesis. We discovered that CENP-A nucleosomes undergo unique oscillations in human cells, a finding mirrored in a parallel study performed in budding yeast. This review provides additional insights into the potential mechanisms for the interconversion of CENP-A nucleosomal species, and speculates on a biological role for oscillations in vivo.
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Affiliation(s)
- Minh Bui
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD USA
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Current progress on structural studies of nucleosomes containing histone H3 variants. Curr Opin Struct Biol 2012; 23:109-15. [PMID: 23265997 DOI: 10.1016/j.sbi.2012.10.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/21/2012] [Accepted: 10/25/2012] [Indexed: 02/04/2023]
Abstract
The nucleosome is the basic repeating unit of chromatin. During the nucleosome assembly process, DNA is wrapped around two H3-H4 dimers, followed by the inclusion of two H2A-H2B dimers. The H3-H4 dimers provide the fundamental architecture of the nucleosome. Many non-allelic variants have been found for H3, but not for H4, suggesting that the functions of chromatin domains may, at least in part, be dictated by the specific H3 variant that is incorporated. A prominent example is the centromeric H3 variant, CENP-A, which specifies the function of centromeres in chromosomes. In this review, we survey the current progress in the studies of nucleosomes containing H3 variants, and discuss their implications for the architecture and dynamics of chromatin domains.
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Tachiwana H, Kagawa W, Kurumizaka H. Comparison between the CENP-A and histone H3 structures in nucleosomes. Nucleus 2012; 3:6-11. [PMID: 22127263 DOI: 10.4161/nucl.18372] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Centromeres are epigenetically marked by the assembly of nucleosomes containing the centromere-specific histone H3 variant, CENP-A (CENP-A nucleosome) and their inheritance is probably dictated by the architecture of the centromeric nucleosome. We previously determined the crystal structure of the human CENP-A nucleosome. CENP-A forms a histone octamer containing two each of histones H2A, H2B, H4 and CENP-A and the DNA is left-handedly wrapped around the histone octamer, as in canonical nucleosomes containing histone H3. In the CENP-A nucleosome structure, 13 base pairs of the DNA ends are detached from the histone surface and two CENP-A regions, the αN helix and loop 1, adopt different structures from those in the H3 nucleosome. In this Extra View article, we provide a detailed structural comparison between CENP-A and H3 in nucleosomes and describe their distinctions and similarities.
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Affiliation(s)
- Hiroaki Tachiwana
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
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Abstract
Centromeres, the sites of spindle attachment during mitosis and meiosis, are located in specific positions in the human genome, normally coincident with diverse subsets of alpha satellite DNA. While there is strong evidence supporting the association of some subfamilies of alpha satellite with centromere function, the basis for establishing whether a given alpha satellite sequence is or is not designated a functional centromere is unknown, and attempts to understand the role of particular sequence features in establishing centromere identity have been limited by the near identity and repetitive nature of satellite sequences. Utilizing a broadly applicable experimental approach to test sequence competency for centromere specification, we have carried out a genomic and epigenetic functional analysis of endogenous human centromere sequences available in the current human genome assembly. The data support a model in which functionally competent sequences confer an opportunity for centromere specification, integrating genomic and epigenetic signals and promoting the concept of context-dependent centromere inheritance.
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Quénet D, Dalal Y. The CENP-A nucleosome: a dynamic structure and role at the centromere. Chromosome Res 2012; 20:465-79. [PMID: 22825424 DOI: 10.1007/s10577-012-9301-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The centromere is a specialized locus that directs the formation of the kinetochore protein complex for correct chromosome segregation. The specific centromere histone H3 variant CENP-A has been described as the epigenetic mark of this chromatin region. Several laboratories have explored its properties, its partners, and its role in centromere formation. Specifically, two types of CENP-A nucleosomes have been described, suggesting there may be more complexity involved in centromere structure than previously thought. Recent work adds to this paradox by questioning the role of CENP-A as a unique centromeric mark and highlighting the assembly of a functional kinetochore in the absence of CENP-A. In this review, we discuss recent literature on the CENP-A nucleosomes and the debate on its role in kinetochore formation and centromere identity.
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Affiliation(s)
- Delphine Quénet
- Laboratory of Receptor Biology & Gene Expression-NCI-NIH, Building 41, Room B901, 41 Library Drive MSC 5055, Bethesda, MD 20892, USA
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Shivaraju M, Unruh JR, Slaughter BD, Mattingly M, Berman J, Gerton JL. Cell-cycle-coupled structural oscillation of centromeric nucleosomes in yeast. Cell 2012; 150:304-16. [PMID: 22817893 DOI: 10.1016/j.cell.2012.05.034] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 03/16/2012] [Accepted: 05/18/2012] [Indexed: 11/17/2022]
Abstract
The centromere is a specialized chromosomal structure that regulates chromosome segregation. Centromeres are marked by a histone H3 variant. In budding yeast, the histone H3 variant Cse4 is present in a single centromeric nucleosome. Experimental evidence supports several different models for the structure of centromeric nucleosomes. To investigate Cse4 copy number in live yeast, we developed a method coupling fluorescence correlation spectroscopy and calibrated imaging. We find that centromeric nucleosomes have one copy of Cse4 during most of the cell cycle, whereas two copies are detected at anaphase. The proposal of an anaphase-coupled structural change is supported by Cse4-Cse4 interactions, incorporation of Cse4, and the absence of Scm3 in anaphase. Nucleosome reconstitution and ChIP suggests both Cse4 structures contain H2A/H2B. The increase in Cse4 intensity and deposition at anaphase are also observed in Candida albicans. Our experimental evidence supports a cell-cycle-coupled oscillation of centromeric nucleosome structure in yeast.
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