1
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Pande S, Ghosh DK. Nuclear proteostasis imbalance in laminopathy-associated premature aging diseases. FASEB J 2023; 37:e23116. [PMID: 37498235 DOI: 10.1096/fj.202300878r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/15/2023] [Accepted: 07/13/2023] [Indexed: 07/28/2023]
Abstract
Laminopathies are a group of rare genetic disorders with heterogeneous clinical phenotypes such as premature aging, cardiomyopathy, lipodystrophy, muscular dystrophy, microcephaly, epilepsy, and so on. The cellular phenomena associated with laminopathy invariably show disruption of nucleoskeleton of lamina due to deregulated expression, localization, function, and interaction of mutant lamin proteins. Impaired spatial and temporal tethering of lamin proteins to the lamina or nucleoplasmic aggregation of lamins are the primary molecular events that can trigger nuclear proteotoxicity by modulating differential protein-protein interactions, sequestering quality control proteins, and initiating a cascade of abnormal post-translational modifications. Clearly, laminopathic cells exhibit moderate to high nuclear proteotoxicity, raising the question of whether an imbalance in nuclear proteostasis is involved in laminopathic diseases, particularly in diseases of early aging such as HGPS and laminopathy-associated premature aging. Here, we review nuclear proteostasis and its deregulation in the context of lamin proteins and laminopathies.
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Affiliation(s)
- Shruti Pande
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Debasish Kumar Ghosh
- Enteric Disease Division, Department of Microbiology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
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2
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Singh AK, Saharan K, Baral S, Vasudevan D. The plant nucleoplasmin AtFKBP43 needs its extended arms for histone interaction. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2022; 1865:194872. [PMID: 36058470 DOI: 10.1016/j.bbagrm.2022.194872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/20/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
The nucleoplasmin family of histone chaperones is a key player in governing the dynamic architecture of chromatin, thereby regulating various DNA-templated processes. The crystal structure of the N-terminal domain of Arabidopsis thaliana FKBP43 (AtFKBP43), an FK506-binding immunophilin protein, revealed a characteristic nucleoplasmin fold, thus confirming it to be a member of the FKBP nucleoplasmin class. Small-Angle X-ray Scattering (SAXS) analyses confirmed its pentameric nature in solution, and additional studies confirmed the nucleoplasmin fold to be highly stable. Unlike its homolog AtFKBP53, the AtFKBP43 nucleoplasmin core domain could not interact with histones and required the acidic arms, C-terminal to the core, for histone association. However, SAXS generated low-resolution envelope structure, ITC, and AUC results revealed that an AtFKBP43 pentamer with C-terminal extensions interacts with H2A/H2B dimer and H3/H4 tetramer in an equimolar ratio, like AtFKBP53. Put together, AtFKBP43 belongs to a hitherto unreported subclass of FKBP nucleoplasmins that requires the C-terminal acidic stretches emanating from the core domain for histone interaction.
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Affiliation(s)
| | - Ketul Saharan
- Institute of Life Sciences, Bhubaneswar 751023, India; Regional Centre for Biotechnology, Faridabad 121001, India
| | - Somanath Baral
- Institute of Life Sciences, Bhubaneswar 751023, India; School of Biotechnology, KIIT University, Bhubaneswar 751024, India
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3
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A tri-functional amino acid enables mapping of binding sites for posttranslational-modification-mediated protein-protein interactions. Mol Cell 2021; 81:2669-2681.e9. [PMID: 33894155 DOI: 10.1016/j.molcel.2021.04.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/01/2021] [Accepted: 03/31/2021] [Indexed: 12/16/2022]
Abstract
Posttranslational modification (PTM), through the recruitment of effector proteins (i.e., "readers") that signal downstream events, plays key roles in regulating a variety of cellular processes. To understand how a PTM is recognized, it is necessary to find its readers and, importantly, the location of the binding pockets responsible for PTM recognition. Although various methods have been developed to identify PTM readers, it remains a challenge to directly map the PTM-binding regions, especially for intrinsically disordered domains. Here, we demonstrate a photo-crosslinkable, clickable, and cleavable tri-functional amino acid, ADdis-Cys, that when coupled with mass spectrometry (ADdis-Cys-MS) can not only identify PTM readers from complex proteomes but also simultaneously map their PTM-recognition modules. Using ADdis-Cys-MS, we successfully identify the binding sites of several reader-PTM interactions, among which we discover human C1QBP as a histone chaperone. This robust method should find wide applications in examining other histone or non-histone PTM-mediated protein-protein interactions.
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4
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Okimune KI, Nagy SK, Hataya S, Endo Y, Takasuka TE. Reconstitution of Drosophila and human chromatins by wheat germ cell-free co-expression system. BMC Biotechnol 2020; 20:62. [PMID: 33261588 PMCID: PMC7708258 DOI: 10.1186/s12896-020-00655-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 11/10/2020] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Elaboration of the epigenetic regulation of chromatin is a long-standing aim in molecular and cellular biology. Hence, there is a great demand for the development of in vitro methods to reconstitute chromatin that can be used directly for biochemical assays. The widely used wheat germ cell-free protein expression method provides broad applications to investigate the function and structure of eukaryotic proteins. Such advantages, including high translation efficiency, flexibility, and possible automatization, are beneficial for achieving native-like chromatin substrates for in vitro studies. RESULTS We describe a novel, single-step in vitro chromatin assembly method by using the wheat germ cell-free protein synthesis. We demonstrated that both Drosophila and human chromatins can be reconstituted in the course of the in vitro translation of core histones by the addition of chromatin assembly factors, circular plasmid, and topoisomerase I in an ATP-dependent manner. Drosophila chromatin assembly was performed in 4 h at 26 °C, in the presence of premixed mRNAs encoding the core histones, dAcf1/dISWI chromatin remodeling complex, and nucleosome assembly protein, dNAP1. Similarly, the human chromatin was assembled by co-expressing the human core histones with Drosophila chromatin remodeling factor, dISWI, and chromatin chaperone, dNLP, for 6 h at 26 °C. The presence of reconstituted chromatin was monitored by DNA supercoiling assay, also the regular spacing of nucleosomes was assessed by Micrococcal nuclease assay. Furthermore, Drosophila linker histone H1-containing chromatin was reconstituted, affirming that the in vitro assembled chromatin is suitable for downstream applications. CONCLUSIONS The method described in this study allows the assembly of Drosophila and human chromatins, possibly in native-like form, by using a wheat germ cell-free protein expression. Although both chromatins were reconstituted successfully, there were unexpected differences with respect to the required ratio of histone-coding mRNAs and the reaction time. Overall, our new in vitro chromatin reconstitution method will aid to characterize the unrevealed structure, function, and regulation of chromatin dynamics.
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Affiliation(s)
- Kei-Ichi Okimune
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.,Graduate School of Global Food Resources, Hokkaido University, Sapporo, Japan
| | - Szilvia K Nagy
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.,Department of Molecular Biology, Institute of Biochemistry and Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Shogo Hataya
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Yaeta Endo
- Proteo-Science Center of Ehime University, Matsuyama, Japan
| | - Taichi E Takasuka
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan. .,Graduate School of Global Food Resources, Hokkaido University, Sapporo, Japan. .,GI-CORE, Hokkaido University, Sapporo, 060-8589, Japan.
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5
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Mechanistic and structural insights into histone H2A–H2B chaperone in chromatin regulation. Biochem J 2020; 477:3367-3386. [DOI: 10.1042/bcj20190852] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/15/2020] [Accepted: 08/21/2020] [Indexed: 11/17/2022]
Abstract
Histone chaperones include a wide variety of proteins which associate with histones and regulate chromatin structure. The classic H2A–H2B type of histone chaperones, and the chromatin remodeling complex components possessing H2A–H2B chaperone activity, show a broad range of structures and functions. Rapid progress in the structural and functional study of H2A–H2B chaperones extends our knowledge about the epigenetic regulation of chromatin. In this review, we summarize the most recent advances in the understanding of the structure and function of H2A–H2B chaperones that interact with either canonical or variant H2A–H2B dimers. We discuss the current knowledge of the H2A–H2B chaperones, which present no preference for canonical and variant H2A–H2B dimers, describing how they interact with H2A–H2B to fulfill their functions. We also review recent advances of H2A variant-specific chaperones, demarcating how they achieve specific recognition for histone variant H2A.Z and how these interactions regulate chromatin structure by nucleosome editing. We highlight the universal mechanism underlying H2A–H2B dimers recognition by a large variety of histone chaperones. These findings will shed insight into the biological impacts of histone chaperone, chromatin remodeling complex, and histone variants in chromatin regulation.
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6
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Singh AK, Datta A, Jobichen C, Luan S, Vasudevan D. AtFKBP53: a chimeric histone chaperone with functional nucleoplasmin and PPIase domains. Nucleic Acids Res 2020; 48:1531-1550. [PMID: 31807785 PMCID: PMC7026663 DOI: 10.1093/nar/gkz1153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/20/2019] [Accepted: 12/02/2019] [Indexed: 12/23/2022] Open
Abstract
FKBP53 is one of the seven multi-domain FK506-binding proteins present in Arabidopsis thaliana, and it is known to get targeted to the nucleus. It has a conserved PPIase domain at the C-terminus and a highly charged N-terminal stretch, which has been reported to bind to histone H3 and perform the function of a histone chaperone. To better understand the molecular details of this PPIase with histone chaperoning activity, we have solved the crystal structures of its terminal domains and functionally characterized them. The C-terminal domain showed strong PPIase activity, no role in histone chaperoning and revealed a monomeric five-beta palm-like fold that wrapped over a helix, typical of an FK506-binding domain. The N-terminal domain had a pentameric nucleoplasmin-fold; making this the first report of a plant nucleoplasmin structure. Further characterization revealed the N-terminal nucleoplasmin domain to interact with H2A/H2B and H3/H4 histone oligomers, individually, as well as simultaneously, suggesting two different binding sites for H2A/H2B and H3/H4. The pentameric domain assists nucleosome assembly and forms a discrete complex with pre-formed nucleosomes; wherein two pentamers bind to a nucleosome.
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Affiliation(s)
- Ajit Kumar Singh
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar 751023, India.,Manipal Academy of Higher Education, Manipal 576104, India
| | - Aritreyee Datta
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar 751023, India
| | - Chacko Jobichen
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore 117543
| | - Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Dileep Vasudevan
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar 751023, India
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7
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Kumar A, Vasudevan D. Structure-function relationship of H2A-H2B specific plant histone chaperones. Cell Stress Chaperones 2020; 25:1-17. [PMID: 31707537 PMCID: PMC6985425 DOI: 10.1007/s12192-019-01050-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/15/2019] [Accepted: 10/28/2019] [Indexed: 10/25/2022] Open
Abstract
Studies on chromatin structure and function have gained a revived popularity. Histone chaperones are significant players in chromatin organization. They play a significant role in vital nuclear functions like transcription, DNA replication, DNA repair, DNA recombination, and epigenetic regulation, primarily by aiding processes such as histone shuttling and nucleosome assembly/disassembly. Like the other eukaryotes, plants also have a highly orchestrated and dynamic chromatin organization. Plants seem to have more isoforms within the same family of histone chaperones, as compared with other organisms. As some of these are specific to plants, they must have evolved to perform functions unique to plants. However, it appears that only little effort has gone into understanding the structural features of plant histone chaperones and their structure-function relationships. Studies on plant histone chaperones are essential for understanding their role in plant chromatin organization and how plants respond during stress conditions. This review is on the structural and functional aspects of plant histone chaperone families, specifically those which bind to H2A-H2B, viz nucleosome assembly protein (NAP), nucleoplasmin (NPM), and facilitates chromatin transcription (FACT). Here, we also present comparative analyses of these plant histone chaperones with available histone chaperone structures. The review hopes to incite interest among researchers to pursue further research in the area of plant chromatin and the associated histone chaperones.
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Affiliation(s)
- Ashish Kumar
- Institute of Life Sciences, Bhubaneswar, Odisha, 751023, India
- Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
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8
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Structural insights into the ability of nucleoplasmin to assemble and chaperone histone octamers for DNA deposition. Sci Rep 2019; 9:9487. [PMID: 31263230 PMCID: PMC6602930 DOI: 10.1038/s41598-019-45726-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/12/2019] [Indexed: 12/13/2022] Open
Abstract
Nucleoplasmin (NP) is a pentameric histone chaperone that regulates the condensation state of chromatin in different cellular processes. We focus here on the interaction of NP with the histone octamer, showing that NP could bind sequentially the histone components to assemble an octamer-like particle, and crosslinked octamers with high affinity. The three-dimensional reconstruction of the NP/octamer complex generated by single-particle cryoelectron microscopy, revealed that several intrinsically disordered tail domains of two NP pentamers, facing each other through their distal face, encage the histone octamer in a nucleosome-like conformation and prevent its dissociation. Formation of this complex depended on post-translational modification and exposure of the acidic tract at the tail domain of NP. Finally, NP was capable of transferring the histone octamers to DNA in vitro, assembling nucleosomes. This activity may have biological relevance for processes in which the histone octamer must be rapidly removed from or deposited onto the DNA.
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9
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Warren C, Matsui T, Karp JM, Onikubo T, Cahill S, Brenowitz M, Cowburn D, Girvin M, Shechter D. Dynamic intramolecular regulation of the histone chaperone nucleoplasmin controls histone binding and release. Nat Commun 2017; 8:2215. [PMID: 29263320 PMCID: PMC5738438 DOI: 10.1038/s41467-017-02308-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 11/17/2017] [Indexed: 12/21/2022] Open
Abstract
Nucleoplasmin (Npm) is a highly conserved histone chaperone responsible for the maternal storage and zygotic release of histones H2A/H2B. Npm contains a pentameric N-terminal core domain and an intrinsically disordered C-terminal tail domain. Though intrinsically disordered regions are common among histone chaperones, their roles in histone binding and chaperoning remain unclear. Using an NMR-based approach, here we demonstrate that the Xenopus laevis Npm tail domain controls the binding of histones at its largest acidic stretch (A2) via direct competition with both the C-terminal basic stretch and basic nuclear localization signal. NMR and small-angle X-ray scattering (SAXS) structural analyses allowed us to construct models of both the tail domain and the pentameric complex. Functional analyses demonstrate that these competitive intramolecular interactions negatively regulate Npm histone chaperone activity in vitro. Together these data establish a potentially generalizable mechanism of histone chaperone regulation via dynamic and specific intramolecular shielding of histone interaction sites.
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Affiliation(s)
- Christopher Warren
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Tsutomu Matsui
- Department of Chemistry, Stanford University, Stanford Synchrotron Radiation Lightsource, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Jerome M Karp
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Takashi Onikubo
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
- Laboratory of Biochemistry and Molecular Biology, Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Sean Cahill
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Michael Brenowitz
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | - David Cowburn
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Mark Girvin
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | - David Shechter
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
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10
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Bose D, Chakrabarti A. Substrate specificity in the context of molecular chaperones. IUBMB Life 2017; 69:647-659. [PMID: 28748601 DOI: 10.1002/iub.1656] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/03/2017] [Indexed: 12/23/2022]
Abstract
Molecular chaperones are one of the key players in protein biology and as such their structure and mechanism of action have been extensively studied. However the substrate specificity of molecular chaperones has not been well investigated. This review aims to summarize what is known about the substrate specificity and substrate recognition motifs of chaperones so as to better understand what substrate specificity means in the context of molecular chaperones. Available literature shows that the majority of chaperones have broad substrate range and recognize non-native conformations of proteins depending on recognition of hydrophobic and/or charged patches. Based on these recognition motifs chaperones can select for early, mid or late folding intermediates. Another major contributor to chaperone specificity are the co-chaperones they interact with as well as the sub-cellular location they are expressed in and the inducability of their expression. Some chaperones which have only one or a few known substrates are reported. In their case the mode of recognition seems to be specific structural complementarity between chaperone and substrate. It can be concluded that the vast majority of chaperones do not show a high degree of specificity but recognize elements that signal non-native protein conformation and their substrate range is modulated by the context they function in. However a few chaperones are known that display exquisite specificity of their substrate e.g. mammalian heat shock protein 47 collagen interaction. © 2017 IUBMB Life, 69(9):647-659, 2017.
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Affiliation(s)
- Dipayan Bose
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, HBNI, Kolkata, India
| | - Abhijit Chakrabarti
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, HBNI, Kolkata, India
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11
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Warren C, Shechter D. Fly Fishing for Histones: Catch and Release by Histone Chaperone Intrinsically Disordered Regions and Acidic Stretches. J Mol Biol 2017; 429:2401-2426. [PMID: 28610839 DOI: 10.1016/j.jmb.2017.06.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/05/2017] [Accepted: 06/06/2017] [Indexed: 01/21/2023]
Abstract
Chromatin is the complex of eukaryotic DNA and proteins required for the efficient compaction of the nearly 2-meter-long human genome into a roughly 10-micron-diameter cell nucleus. The fundamental repeating unit of chromatin is the nucleosome: 147bp of DNA wrapped about an octamer of histone proteins. Nucleosomes are stable enough to organize the genome yet must be dynamically displaced and reassembled to allow access to the underlying DNA for transcription, replication, and DNA damage repair. Histone chaperones are a non-catalytic group of proteins that are central to the processes of nucleosome assembly and disassembly and thus the fluidity of the ever-changing chromatin landscape. Histone chaperones are responsible for binding the highly basic histone proteins, shielding them from non-specific interactions, facilitating their deposition onto DNA, and aiding in their eviction from DNA. Although most histone chaperones perform these common functions, recent structural studies of many different histone chaperones reveal that there are few commonalities in their folds. Importantly, sequence-based predictions show that histone chaperones are highly enriched in intrinsically disordered regions (IDRs) and acidic stretches. In this review, we focus on the molecular mechanisms underpinning histone binding, selectivity, and regulation of these highly dynamic protein regions. We highlight new evidence suggesting that IDRs are often critical for histone chaperone function and play key roles in chromatin assembly and disassembly pathways.
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Affiliation(s)
- Christopher Warren
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - David Shechter
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
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12
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Hammond CM, Strømme CB, Huang H, Patel DJ, Groth A. Histone chaperone networks shaping chromatin function. Nat Rev Mol Cell Biol 2017; 18:141-158. [PMID: 28053344 DOI: 10.1038/nrm.2016.159] [Citation(s) in RCA: 328] [Impact Index Per Article: 46.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The association of histones with specific chaperone complexes is important for their folding, oligomerization, post-translational modification, nuclear import, stability, assembly and genomic localization. In this way, the chaperoning of soluble histones is a key determinant of histone availability and fate, which affects all chromosomal processes, including gene expression, chromosome segregation and genome replication and repair. Here, we review the distinct structural and functional properties of the expanding network of histone chaperones. We emphasize how chaperones cooperate in the histone chaperone network and via co-chaperone complexes to match histone supply with demand, thereby promoting proper nucleosome assembly and maintaining epigenetic information by recycling modified histones evicted from chromatin.
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Affiliation(s)
- Colin M Hammond
- Biotech Research and Innovation Centre (BRIC) and Centre for Epigenetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Caroline B Strømme
- Biotech Research and Innovation Centre (BRIC) and Centre for Epigenetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Hongda Huang
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Anja Groth
- Biotech Research and Innovation Centre (BRIC) and Centre for Epigenetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
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13
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A Quantitative Characterization of Nucleoplasmin/Histone Complexes Reveals Chaperone Versatility. Sci Rep 2016; 6:32114. [PMID: 27558753 PMCID: PMC4997359 DOI: 10.1038/srep32114] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 08/02/2016] [Indexed: 01/29/2023] Open
Abstract
Nucleoplasmin (NP) is an abundant histone chaperone in vertebrate oocytes and embryos involved in storing and releasing maternal histones to establish and maintain the zygotic epigenome. NP has been considered a H2A-H2B histone chaperone, and recently it has been shown that it can also interact with H3-H4. However, its interaction with different types of histones has not been quantitatively studied so far. We show here that NP binds H2A-H2B, H3-H4 and linker histones with Kd values in the subnanomolar range, forming different complexes. Post-translational modifications of NP regulate exposure of the polyGlu tract at the disordered distal face of the protein and induce an increase in chaperone affinity for all histones. The relative affinity of NP for H2A-H2B and linker histones and the fact that they interact with the distal face of the chaperone could explain their competition for chaperone binding, a relevant process in NP-mediated sperm chromatin remodelling during fertilization. Our data show that NP binds H3-H4 tetramers in a nucleosomal conformation and dimers, transferring them to DNA to form disomes and tetrasomes. This finding might be relevant to elucidate the role of NP in chromatin disassembly and assembly during replication and transcription.
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14
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Ellard K, Serpa JJ, Petrotchenko EV, Borchers CH, Ausió J. Expression and purification of the full murine NPM2 and study of its interaction with protamines and histones. Biochem Biophys Rep 2016; 6:165-171. [PMID: 28955874 PMCID: PMC5600342 DOI: 10.1016/j.bbrep.2016.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 03/19/2016] [Accepted: 04/04/2016] [Indexed: 11/27/2022] Open
Abstract
Mouse nucleoplasmin M.NPM2 was recombinantly expressed and the protein consisting of the complete sequence was purified and characterized. Similar to its Xenopus laevis X.NPM2 counterpart, the protein forms stable pentameric complexes and exhibits an almost undistinguishable hydrodynamic ionic strength-dependent unfolding behavior. The interaction of N.PM2 with histones and mouse P1/P2 protamines revealed that these chromosomal proteins bind preferentially to the distal part of the nucleoplasmin pentamer. Moreover, the present work highlights the critical role played by histones H2B and H4 in the association of the histone H2A-H2B dimers and histone octamer with nucleoplasmin. Characterization of the entire mouse M.NPM2 protein. Determination of sites of interaction of M.NPM2 with histones and mouse protamines. Use of crosslinking mass spectrometry to determine protein-protein interactions. Analysis of the C-terminal NPM2 unfolding.
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Affiliation(s)
- Katherine Ellard
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8W 3P6
| | - Jason J Serpa
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8W 3P6.,Genome British Columbia Proteomics Centre, University of Victoria, Victoria, BC, Canada V8Z 7X8
| | - Evgeniy V Petrotchenko
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8W 3P6.,Genome British Columbia Proteomics Centre, University of Victoria, Victoria, BC, Canada V8Z 7X8
| | - Christoph H Borchers
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8W 3P6.,Genome British Columbia Proteomics Centre, University of Victoria, Victoria, BC, Canada V8Z 7X8
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8W 3P6
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15
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Edlich-Muth C, Artero JB, Callow P, Przewloka MR, Watson AA, Zhang W, Glover DM, Debski J, Dadlez M, Round AR, Forsyth VT, Laue ED. The pentameric nucleoplasmin fold is present in Drosophila FKBP39 and a large number of chromatin-related proteins. J Mol Biol 2015; 427:1949-63. [PMID: 25813344 PMCID: PMC4414354 DOI: 10.1016/j.jmb.2015.03.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 03/17/2015] [Accepted: 03/17/2015] [Indexed: 11/28/2022]
Abstract
Nucleoplasmin is a histone chaperone that consists of a pentameric N-terminal domain and an unstructured C-terminal tail. The pentameric core domain, a doughnut-like structure with a central pore, is only found in the nucleoplasmin family. Here, we report the first structure of a nucleoplasmin-like domain (NPL) from the unrelated Drosophila protein, FKBP39, and we present evidence that this protein associates with chromatin. Furthermore, we show that two other chromatin proteins, Arabidopsis thaliana histone deacetylase type 2 (HD2) and Saccharomyces cerevisiae Fpr4, share the NPL fold and form pentamers, or a dimer of pentamers in the case of HD2. Thus, we propose a new family of proteins that share the pentameric nucleoplasmin-like NPL domain and are found in protists, fungi, plants and animals.
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Affiliation(s)
- Christian Edlich-Muth
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, CB2 1GA Cambridge, United Kingdom
| | - Jean-Baptiste Artero
- Life Sciences Group, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, Grenoble, Cedex 9, France; Faculty of Natural Sciences, Keele University, ST5 5BG Staffordshire, United Kingdom
| | - Phil Callow
- Life Sciences Group, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, Grenoble, Cedex 9, France; Faculty of Natural Sciences, Keele University, ST5 5BG Staffordshire, United Kingdom
| | - Marcin R Przewloka
- Department of Genetics, University of Cambridge, Downing Street, CB2 3EH Cambridge, United Kingdom
| | - Aleksandra A Watson
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, CB2 1GA Cambridge, United Kingdom
| | - Wei Zhang
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, CB2 1GA Cambridge, United Kingdom
| | - David M Glover
- Department of Genetics, University of Cambridge, Downing Street, CB2 3EH Cambridge, United Kingdom
| | - Janusz Debski
- Mass Spectrometry Laboratory, Department of Biophysics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 5A Pawinskiego Street, 02-106 Warsaw, Poland
| | - Michal Dadlez
- Mass Spectrometry Laboratory, Department of Biophysics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 5A Pawinskiego Street, 02-106 Warsaw, Poland
| | - Adam R Round
- European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, 38042 Grenoble, France; Unit for Virus Host-Cell Interactions, University Grenoble Alpes-European Molecular Biology Laboratory-CNRS, 71 Avenue des Martyrs, 38042 Grenoble, France; Faculty of Natural Sciences, Keele University, ST5 5BG Staffordshire, United Kingdom
| | - V Trevor Forsyth
- Life Sciences Group, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, Grenoble, Cedex 9, France; Faculty of Natural Sciences, Keele University, ST5 5BG Staffordshire, United Kingdom
| | - Ernest D Laue
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, CB2 1GA Cambridge, United Kingdom.
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16
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Developmentally Regulated Post-translational Modification of Nucleoplasmin Controls Histone Sequestration and Deposition. Cell Rep 2015; 10:1735-1748. [PMID: 25772360 DOI: 10.1016/j.celrep.2015.02.038] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 01/09/2015] [Accepted: 02/13/2015] [Indexed: 11/23/2022] Open
Abstract
Nucleoplasmin (Npm) is an abundant histone chaperone in vertebrate oocytes and embryos. During embryogenesis, regulation of Npm histone binding is critical for its function in storing and releasing maternal histones to establish and maintain the zygotic epigenome. Here, we demonstrate that Xenopus laevis Npm post-translational modifications (PTMs) specific to the oocyte and egg promote either histone deposition or sequestration, respectively. Mass spectrometry and Npm phosphomimetic mutations used in chromatin assembly assays identified hyperphosphorylation on the N-terminal tail as a critical regulator for sequestration. C-terminal tail phosphorylation and PRMT5-catalyzed arginine methylation enhance nucleosome assembly by promoting histone interaction with the second acidic tract of Npm. Electron microscopy reconstructions of Npm and TTLL4 activity toward the C-terminal tail demonstrate that oocyte- and egg-specific PTMs cause Npm conformational changes. Our results reveal that PTMs regulate Npm chaperoning activity by modulating Npm conformation and Npm-histone interaction, leading to histone sequestration in the egg.
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17
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Ramos I, Fernández-Rivero N, Arranz R, Aloria K, Finn R, Arizmendi JM, Ausió J, Valpuesta JM, Muga A, Prado A. The intrinsically disordered distal face of nucleoplasmin recognizes distinct oligomerization states of histones. Nucleic Acids Res 2013; 42:1311-25. [PMID: 24121686 PMCID: PMC3902905 DOI: 10.1093/nar/gkt899] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The role of Nucleoplasmin (NP) as a H2A-H2B histone chaperone has been extensively characterized. To understand its putative interaction with other histone ligands, we have characterized its ability to bind H3-H4 and histone octamers. We find that the chaperone forms distinct complexes with histones, which differ in the number of molecules that build the assembly and in their spatial distribution. When complexed with H3-H4 tetramers or histone octamers, two NP pentamers form an ellipsoidal particle with the histones located at the center of the assembly, in stark contrast with the NP/H2A-H2B complex that contains up to five histone dimers bound to one chaperone pentamer. This particular assembly relies on the ability of H3-H4 to form tetramers either in solution or as part of the octamer, and it is not observed when a variant of H3 (H3C110E), unable to form stable tetramers, is used instead of the wild-type protein. Our data also suggest that the distal face of the chaperone is involved in the interaction with distinct types of histones, as supported by electron microscopy analysis of the different NP/histone complexes. The use of the same structural region to accommodate all type of histones could favor histone exchange and nucleosome dynamics.
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Affiliation(s)
- Isbaal Ramos
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencia y Tecnología, Universidad del PaísVasco, P. O. Box 644, 48080 Bilbao, Spain, Unidad de Biofísica (Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea), Barrio Sarriena s/n, 48080 Leioa Spain, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain and Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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18
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Teperek M, Miyamoto K. Nuclear reprogramming of sperm and somatic nuclei in eggs and oocytes. Reprod Med Biol 2013; 12:133-149. [PMID: 24273450 PMCID: PMC3824936 DOI: 10.1007/s12522-013-0155-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 05/18/2013] [Indexed: 10/26/2022] Open
Abstract
Eggs and oocytes have a prominent ability to reprogram sperm nuclei for ensuring embryonic development. The reprogramming activity that eggs/oocytes intrinsically have towards sperm is utilised to reprogram somatic nuclei injected into eggs/oocytes in nuclear transfer (NT) embryos. NT embryos of various species can give rise to cloned animals, demonstrating that eggs/oocytes can confer totipotency even to somatic nuclei. However, many studies indicate that reprogramming of somatic nuclei is not as efficient as that of sperm nuclei. In this review, we explain how and why sperm and somatic nuclei are differentially reprogrammed in eggs/oocytes. Recent studies have shown that sperm chromatin is epigenetically modified to be adequate for early embryonic development, while somatic nuclei do not have such modifications. Moreover, epigenetic memories encoded in sperm chromatin are transgenerationally inherited, implying unique roles of sperm. We also discuss whether somatic nuclei can be artificially modified to acquire sperm-like chromatin states in order to increase the efficiency of nuclear reprogramming.
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Affiliation(s)
- Marta Teperek
- The Wellcome Trust/Cancer Research UK Gurdon Institute, The Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, CB2 1QN Cambridge, United Kingdom ; Department of Zoology, University of Cambridge, Cambridge, United Kingdom
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19
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Abstract
Chromatin acts as an organizer and indexer of genomic DNA and is a highly dynamic and regulated structure with properties directly related to its constituent parts. Histone variants are abundant components of chromatin that replace canonical histones in a subset of nucleosomes, thereby altering nucleosomal characteristics. The present review focuses on the H2A variant histones, summarizing current knowledge of how H2A variants can introduce chemical and functional heterogeneity into chromatin, the positions that nucleosomes containing H2A variants occupy in eukaryotic genomes, and the regulation of these localization patterns.
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20
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Structure of the arginine methyltransferase PRMT5-MEP50 reveals a mechanism for substrate specificity. PLoS One 2013; 8:e57008. [PMID: 23451136 PMCID: PMC3581573 DOI: 10.1371/journal.pone.0057008] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 01/16/2013] [Indexed: 01/07/2023] Open
Abstract
The arginine methyltransferase PRMT5-MEP50 is required for embryogenesis and is misregulated in many cancers. PRMT5 targets a wide variety of substrates, including histone proteins involved in specifying an epigenetic code. However, the mechanism by which PRMT5 utilizes MEP50 to discriminate substrates and to specifically methylate target arginines is unclear. To test a model in which MEP50 is critical for substrate recognition and orientation, we determined the crystal structure of Xenopus laevis PRMT5-MEP50 complexed with S-adenosylhomocysteine (SAH). PRMT5-MEP50 forms an unusual tetramer of heterodimers with substantial surface negative charge. MEP50 is required for PRMT5-catalyzed histone H2A and H4 methyltransferase activity and binds substrates independently. The PRMT5 catalytic site is oriented towards the cross-dimer paired MEP50. Histone peptide arrays and solution assays demonstrate that PRMT5-MEP50 activity is inhibited by substrate phosphorylation and enhanced by substrate acetylation. Electron microscopy and reconstruction showed substrate centered on MEP50. These data support a mechanism in which MEP50 binds substrate and stimulates PRMT5 activity modulated by substrate post-translational modifications.
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21
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Finn RM, Ellard K, Eirín-López JM, Ausió J. Vertebrate nucleoplasmin and NASP: egg histone storage proteins with multiple chaperone activities. FASEB J 2012; 26:4788-804. [PMID: 22968912 DOI: 10.1096/fj.12-216663] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recent reviews have focused on the structure and function of histone chaperones involved in different aspects of somatic cell chromatin metabolism. One of the most dramatic chromatin remodeling processes takes place immediately after fertilization and is mediated by egg histone storage chaperones. These include members of the nucleoplasmin (NPM2/NPM3), which are preferentially associated with histones H2A-H2B in the egg and the nuclear autoantigenic sperm protein (NASP) families. Interestingly, in addition to binding and providing storage to H3/H4 in the egg and in somatic cells, NASP has been shown to be a unique genuine chaperone for histone H1. This review revolves around the structural and functional roles of these two families of chaperones whose activity is modulated by their own post-translational modifications (PTMs), particularly phosphorylation. Beyond their important role in the remodeling of paternal chromatin in the early stages of embryogenesis, NPM and NASP members can interact with a plethora of proteins in addition to histones in somatic cells and play a critical role in processes of functional cell alteration, such as in cancer. Despite their common presence in the egg, these two histone chaperones appear to be evolutionarily unrelated. In contrast to members of the NPM family, which share a common monophyletic evolutionary origin, the different types of NASP appear to have evolved recurrently within different taxa.
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Affiliation(s)
- Ron M Finn
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8W 3P6
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22
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Wilczek C, Chitta R, Woo E, Shabanowitz J, Chait BT, Hunt DF, Shechter D. Protein arginine methyltransferase Prmt5-Mep50 methylates histones H2A and H4 and the histone chaperone nucleoplasmin in Xenopus laevis eggs. J Biol Chem 2011; 286:42221-42231. [PMID: 22009756 PMCID: PMC3234966 DOI: 10.1074/jbc.m111.303677] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 10/17/2011] [Indexed: 12/20/2022] Open
Abstract
Histone proteins carry information contained in post-translational modifications. Eukaryotic cells utilize this histone code to regulate the usage of the underlying DNA. In the maturing oocytes and eggs of the frog Xenopus laevis, histones are synthesized in bulk in preparation for deposition during the rapid early developmental cell cycles. During this key developmental time frame, embryonic pluripotent chromatin is established. In the egg, non-chromatin-bound histones are complexed with storage chaperone proteins, including nucleoplasmin. Here we describe the identification and characterization of a complex of the protein arginine methyltransferase 5 (Prmt5) and the methylosome protein 50 (Mep50) isolated from Xenopus eggs that specifically methylates predeposition histones H2A/H2A.X-F and H4 and the histone chaperone nucleoplasmin on a conserved motif (GRGXK). We demonstrate that nucleoplasmin (Npm), an exceedingly abundant maternally deposited protein, is a potent substrate for Prmt5-Mep50 and is monomethylated and symmetrically dimethylated at Arg-187. Furthermore, Npm modulates Prmt5-Mep50 activity directed toward histones, consistent with a regulatory role for Npm in vivo. We show that H2A and nucleoplasmin methylation appears late in oogenesis and is most abundant in the laid egg. We hypothesize that these very abundant arginine methylations are constrained to pre-mid blastula transition events in the embryo and therefore may be involved in the global transcriptional repression found in this developmental time frame.
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Affiliation(s)
- Carola Wilczek
- Department of Biochemistry, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461
| | - Raghu Chitta
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904
| | - Eileen Woo
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, Rockefeller University, New York, New York 10065
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, Rockefeller University, New York, New York 10065
| | - Donald F Hunt
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904
| | - David Shechter
- Department of Biochemistry, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461.
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23
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Hondele M, Ladurner AG. The chaperone-histone partnership: for the greater good of histone traffic and chromatin plasticity. Curr Opin Struct Biol 2011; 21:698-708. [PMID: 22054910 DOI: 10.1016/j.sbi.2011.10.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 10/11/2011] [Accepted: 10/11/2011] [Indexed: 01/25/2023]
Abstract
Histones are highly positively charged proteins that wrap our genome. Their surface properties also make them prone to nonspecific interactions and aggregation. A class of proteins known as histone chaperones is dedicated to safeguard histones by aiding their proper incorporation into nucleosomes. Histone chaperones facilitate ordered nucleosome assembly and disassembly reactions through the formation of semi-stable histone-chaperone intermediates without requiring ATP, but merely providing a complementary protein surface for histones to dynamically interact with. Recurrent 'chaperoning' mechanisms involve the masking of the histone's positive charge and the direct blocking of crucial histone surface sites, including those required for H3-H4 tetramerization or the binding of nucleosomal DNA. This shielding prevents histones from engaging in premature or unwanted interactions with nucleic acids and other cellular components. In this review, we analyze recent structural studies on chaperone-histone interactions and discuss the implications of this vital partnership for nucleosome assembly and disassembly pathways.
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Affiliation(s)
- Maria Hondele
- Department of Physiological Chemistry, Butenandt Institute of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität München, Butenandtstrasse 5, 81377 Munich, Germany
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24
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Platonova O, Akey IV, Head JF, Akey CW. Crystal structure and function of human nucleoplasmin (npm2): a histone chaperone in oocytes and embryos. Biochemistry 2011; 50:8078-89. [PMID: 21863821 DOI: 10.1021/bi2006652] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Human Npm2 is an ortholog of Xenopus nucleoplasmin (Np), a chaperone that binds histones. We have determined the crystal structure of a truncated Npm2-core at 1.9 Å resolution and show that the N-terminal domains of Npm2 and Np form similar pentamers. This allowed us to model an Npm2 decamer which may be formed by hydrogen bonds between quasi-conserved residues in the interface between two pentamers. Interestingly, the Npm2 pentamer lacks a prototypical A1-acidic tract in each of its subunits. This feature may be responsible for the inability of Npm2-core to bind histones. However, Npm2 with a large acidic tract in its C-terminal tail (Npm2-A2) is able to bind histones and form large complexes. Fluorescence resonance energy transfer experiments and biochemical analysis of loop mutations support the premise that nucleoplasmins form decamers when they bind H2A-H2B dimers and H3-H4 tetramers simultaneously. In the absence of histone tetramers, these chaperones bind H2A-H2B dimers with a single pentamer forming the central hub. When taken together, our data provide insights into the mechanism of histone binding by nucleoplasmins.
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Affiliation(s)
- Olga Platonova
- Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany St., Boston, Massachusetts 02118-2526, USA
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25
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Olguin-Lamas A, Madec E, Hovasse A, Werkmeister E, Callebaut I, Slomianny C, Delhaye S, Mouveaux T, Schaeffer-Reiss C, Van Dorsselaer A, Tomavo S. A novel Toxoplasma gondii nuclear factor TgNF3 is a dynamic chromatin-associated component, modulator of nucleolar architecture and parasite virulence. PLoS Pathog 2011; 7:e1001328. [PMID: 21483487 PMCID: PMC3068996 DOI: 10.1371/journal.ppat.1001328] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 03/01/2011] [Indexed: 01/13/2023] Open
Abstract
In Toxoplasma gondii, cis-acting elements present in promoter sequences of genes that are stage-specifically regulated have been described. However, the nuclear factors that bind to these cis-acting elements and regulate promoter activities have not been identified. In the present study, we performed affinity purification, followed by proteomic analysis, to identify nuclear factors that bind to a stage-specific promoter in T. gondii. This led to the identification of several nuclear factors in T. gondii including a novel factor, designated herein as TgNF3. The N-terminal domain of TgNF3 shares similarities with the N-terminus of yeast nuclear FK506-binding protein (FKBP), known as a histone chaperone regulating gene silencing. Using anti-TgNF3 antibodies, HA-FLAG and YFP-tagged TgNF3, we show that TgNF3 is predominantly a parasite nucleolar, chromatin-associated protein that binds specifically to T. gondii gene promoters in vivo. Genome-wide analysis using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) identified promoter occupancies by TgNF3. In addition, TgNF3 has a direct role in transcriptional control of genes involved in parasite metabolism, transcription and translation. The ectopic expression of TgNF3 in the tachyzoites revealed dynamic changes in the size of the nucleolus, leading to a severe attenuation of virulence in vivo. We demonstrate that TgNF3 physically interacts with H3, H4 and H2A/H2B assembled into bona fide core and nucleosome-associated histones. Furthermore, TgNF3 interacts specifically to histones in the context of stage-specific gene silencing of a promoter that lacks active epigenetic acetylated histone marks. In contrast to virulent tachyzoites, which express the majority of TgNF3 in the nucleolus, the protein is exclusively located in the cytoplasm of the avirulent bradyzoites. We propose a model where TgNF3 acts essentially to coordinate nucleolus and nuclear functions by modulating nucleosome activities during the intracellular proliferation of the virulent tachyzoites of T. gondii. Apicomplexa including Toxoplasma gondii are responsible for a variety of deadly infections. These intracellular parasites have complex life cycles within different hosts and their infectivity relies on their capacity to regulate gene expression in response to different environments. However, to date, little is known about nuclear factors that regulate their gene expression. Here, we have characterized parasite nuclear factors that bind to a stage-specific promoter. We identified several nuclear factors including a novel factor, designated herein as TgNF3. The N-terminal domain of TgNF3 shares similarities with the N-terminus of yeast nuclear FK506-binding protein (FKBP), known as a histone chaperone regulating gene silencing. We show that TgNF3 is predominantly a nucleolar, chromatin-associated protein that specifically binds to T. gondii nucleosome-associated histones and promoters. Genome-wide analysis identified promoter occupancies by TgNF3 and we demonstrated a direct role for this factor in transcriptional control of genes involved in parasite metabolism, transcription and translation. Ectopic expression of TgNF3 induces dynamic changes in the size of the nucleolus, and a severe attenuation of parasite virulence in vivo. In avirulent bradyzoites, TgNF3 is found exclusively in the cytoplasm, suggesting a potential role in regulating nucleolar and nuclear functions in the virulent tachyzoites of T. gondii.
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Affiliation(s)
- Alejandro Olguin-Lamas
- Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U 1019, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique, CNRS UMR 8576, UGSF, Université de Lille 1, Villeneuve d'Ascq, France
| | - Edwige Madec
- Centre National de la Recherche Scientifique, CNRS UMR 8576, UGSF, Université de Lille 1, Villeneuve d'Ascq, France
| | - Agnes Hovasse
- Laboratoire de Spectrométrie de Masse Bioorganique, IPHC, CNRS UMR 7178, Université de Strasbourg, Strasbourg, France
| | - Elisabeth Werkmeister
- Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U 1019, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
| | - Isabelle Callebaut
- Centre National de la Recherche Scientifique, Universités Pierre et Marie Curie-Paris 6 et Denis Diderot-Paris 7, UMR7590, Paris, France
| | - Christian Slomianny
- Laboratoire de Physiologie Cellulaire, INSERM U1003, Université de Lille 1, Villeneuve d'Ascq, France
| | - Stephane Delhaye
- Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U 1019, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique, CNRS UMR 8576, UGSF, Université de Lille 1, Villeneuve d'Ascq, France
| | - Thomas Mouveaux
- Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U 1019, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique, CNRS UMR 8576, UGSF, Université de Lille 1, Villeneuve d'Ascq, France
| | - Christine Schaeffer-Reiss
- Laboratoire de Spectrométrie de Masse Bioorganique, IPHC, CNRS UMR 7178, Université de Strasbourg, Strasbourg, France
| | - Alain Van Dorsselaer
- Laboratoire de Spectrométrie de Masse Bioorganique, IPHC, CNRS UMR 7178, Université de Strasbourg, Strasbourg, France
| | - Stanislas Tomavo
- Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U 1019, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique, CNRS UMR 8576, UGSF, Université de Lille 1, Villeneuve d'Ascq, France
- * E-mail:
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