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Razin SV, Kantidze OL. The twisted path of the 3D genome: where does it lead? Trends Biochem Sci 2022; 47:736-744. [DOI: 10.1016/j.tibs.2022.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/19/2022] [Accepted: 04/11/2022] [Indexed: 01/01/2023]
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2
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Ulianov SV, Razin SV. The two waves in single-cell 3D genomics. Semin Cell Dev Biol 2021; 121:143-152. [PMID: 34030950 DOI: 10.1016/j.semcdb.2021.05.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/11/2021] [Accepted: 05/16/2021] [Indexed: 02/07/2023]
Abstract
For decades, biochemical methods for the analysis of genome structure and function provided cell-population-averaged data that allowed general principles and tendencies to be disclosed. Microscopy-based studies, which immanently involve single-cell analysis, did not provide sufficient spatial resolution to investigate the particularly small details of 3D genome folding. Nevertheless, these studies demonstrated that mutual positions of chromosome territories within cell nuclei and individual genomic loci within chromosomal territories can vary significantly in individual cells. The development of new technologies in biochemistry and the advent of super-resolution microscopy in the last decade have made possible the full-scale study of 3D genome organization in individual cells. Maps of the 3D genome build based on C-data and super-resolution microscopy are highly consistent and, therefore, biologically relevant. The internal structures of individual chromosomes, loci, and topologically associating domains (TADs) are resolved as well as cell-cycle dynamics. 3D modeling allows one to investigate the physical mechanisms underlying genome folding. Finally, joint profiling of genome topology and epigenetic features will allow 3D genomics to handle complex cell-to-cell heterogeneity. In this review, we summarize the present state of studies into 3D genome organization in individual cells, analyze the technical problems of single-cell studies, and outline perspectives of 3D genomics.
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Affiliation(s)
- Sergey V Ulianov
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia.
| | - Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia.
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Karpukhina A, Tiukacheva E, Dib C, Vassetzky YS. Control of DUX4 Expression in Facioscapulohumeral Muscular Dystrophy and Cancer. Trends Mol Med 2021; 27:588-601. [PMID: 33863674 DOI: 10.1016/j.molmed.2021.03.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/10/2021] [Accepted: 03/16/2021] [Indexed: 12/13/2022]
Abstract
DUX4, a gene encoding a transcription factor involved in early embryogenesis, is located within the D4Z4 subtelomeric repeat on chromosome 4q35. In most healthy somatic tissues, DUX4 is heavily repressed by multiple genetic and epigenetic mechanisms, and its aberrant expression is linked to facioscapulohumeral muscular dystrophy (FSHD) where it has been extensively studied. Recently, DUX4 expression has been implicated in oncogenesis, although this is much less explored. In this review, we discuss multiple levels of control of DUX4 expression, including enhancer-promoter interactions, DNA methylation, histone modifications, noncoding RNAs, and telomere positioning effect. We also connect disparate data on intrachromosomal contacts involving DUX4 and emphasize the feedback loops in DUX4 regulation. Finally, we bridge data on DUX4 in FSHD and cancer and discuss prospective approaches for future FSHD therapies and the potential outcomes of DUX4 inhibition in cancer.
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Affiliation(s)
- Anna Karpukhina
- UMR 9018, CNRS, Université Paris Saclay, Institut Gustave Roussy, Villejuif F-94805, France; Koltzov Institute of Developmental Biology, Moscow 117334, Russia; Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Eugenia Tiukacheva
- UMR 9018, CNRS, Université Paris Saclay, Institut Gustave Roussy, Villejuif F-94805, France
| | - Carla Dib
- UMR 9018, CNRS, Université Paris Saclay, Institut Gustave Roussy, Villejuif F-94805, France; Stanford University School of Medicine, Stanford, CA 94305-510, USA
| | - Yegor S Vassetzky
- UMR 9018, CNRS, Université Paris Saclay, Institut Gustave Roussy, Villejuif F-94805, France; Koltzov Institute of Developmental Biology, Moscow 117334, Russia.
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Sjakste T, Leonova E, Petrovs R, Trapina I, Röder MS, Sjakste N. Tight DNA-protein complexes isolated from barley seedlings are rich in potential guanine quadruplex sequences. PeerJ 2020; 8:e8569. [PMID: 32110488 PMCID: PMC7034378 DOI: 10.7717/peerj.8569] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/15/2020] [Indexed: 11/20/2022] Open
Abstract
Background The concept of chromatin domains attached to the nuclear matrix is being revisited, with nucleus described as a set of topologically associating domains. The significance of the tightly bound to DNA proteins (TBP), a protein group that remains attached to DNA after its deproteinization should be also revisited, as the existence of these interactions is in good agreement with the concept of the topologically associating domain. The work aimed to characterize the DNA component of TBP isolated from barley seedlings. Methods The tight DNA-protein complexes from the first leaves, coleoptiles, and roots of barley seedlings were isolated by purification with chromatography on nitrocellulose or exhaustive digestion of DNA with DNase I. Cloning and transformation were performed using pMOSBBlue Blunt Ended Cloning Kit. Inserts were amplified by PCR, and sequencing was performed on the MegaBace 1000 Sequencing System. The BLAST search was performed using sequence databases at NCBI, CR-EST, and TREP and Ensembl Plants databases. Comparison to MAR/SAR sequences was performed using http://smartdb.bioinf.med.uni-goettingen.de/cgi-bin/SMARtDB/smar.cgi database. The prediction of G quadruplexes (GQ) was performed with the aid of R-studio library pqsfinder. CD spectra were recorded on a Chirascan CS/3D spectrometer. Results Although the barley genome is AT-rich (43% of GC pairs), most DNA fragments associated with TBP were GC-rich (up to 70% in some fractions). Both fractionation procedures yielded a high proportion of CT-motif sequences presented predominantly by the 16-bp CC(TCTCCC)2 TC fragment present in clones derived from the TBP-bound DNA and absent in free DNA. BLAST analysis revealed alignment with different barley repeats. Some clones, however, aligned with both nuclear and chloroplast structural genes. Alignments with MAR/SAR motifs were very few. The analysis produced by the pqsfinder program revealed numerous potential quadruplex-forming sites in the TBP-bound sequences. A set of oligonucleotides containing sites of possible GQs were designed and ordered. Three of them represented the minus strand of the CT-repeat. Two were derived from sequences of two clones of nitrocellulose retained fraction from leaves and contained GC-rich motifs different from the CT motif. Circular dichroism spectroscopy revealed profound changes in spectra when oligonucleotides were incubated with 100 mM KCl. There was either an increase of positive band in the area of 260 nm or the formation of a positive band at 290 nm. In the former case, changes are typical for parallel G-quadruplexes and, in the latter, 3 + 1 structures. Discussion The G-quadruplexes anchor proteins are probably involved in the maintenance of the topologically associated domain structure.
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Affiliation(s)
- Tatjana Sjakste
- Genomics and Bioinformatics Group, Institute of Biology, University of Latvia, Riga, Latvia
| | - Elina Leonova
- Faculty of Medicine, University of Latvia, Riga, Latvia
| | | | - Ilva Trapina
- Genomics and Bioinformatics Group, Institute of Biology, University of Latvia, Riga, Latvia
| | - Marion S Röder
- Leibniz Institute for Plant Genetics and Crop Research, Gatersleben, Germany
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5
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Razin SV, Ulianov SV, Gavrilov AA. 3D Genomics. Mol Biol 2019; 53:802-812. [DOI: 10.1134/s0026893319060153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/01/2019] [Accepted: 06/03/2019] [Indexed: 08/30/2023]
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Bazlekowa-Karaban M, Prorok P, Baconnais S, Taipakova S, Akishev Z, Zembrzuska D, Popov AV, Endutkin AV, Groisman R, Ishchenko AA, Matkarimov BT, Bissenbaev A, Le Cam E, Zharkov DO, Tudek B, Saparbaev M. Mechanism of stimulation of DNA binding of the transcription factors by human apurinic/apyrimidinic endonuclease 1, APE1. DNA Repair (Amst) 2019; 82:102698. [PMID: 31518879 DOI: 10.1016/j.dnarep.2019.102698] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 08/11/2019] [Accepted: 08/31/2019] [Indexed: 12/22/2022]
Abstract
Aerobic respiration generates reactive oxygen species (ROS), which can damage nucleic acids, proteins and lipids. A number of transcription factors (TFs) contain redox-sensitive cysteine residues at their DNA-binding sites, hence ROS-induced thiol oxidation strongly inhibits their recognition of the cognate DNA sequences. Major human apurinic/apyrimidinic (AP) endonuclease 1 (APE1/APEX1/HAP-1), referred also as a redox factor 1 (Ref-1), stimulates the DNA binding activities of the oxidized TFs such as AP-1 and NF-κB. Also, APE1 participates in the base excision repair (BER) and nucleotide incision repair (NIR) pathways to remove oxidative DNA base damage. At present, the molecular mechanism underlying the TF-stimulating/redox function of APE1 and its biological role remains disputed. Here, we provide evidence that, instead of direct cysteine reduction in TFs by APE1, APE1-catalyzed NIR and TF-stimulating activities may be based on transient cooperative binding of APE1 to DNA and induction of conformational changes in the helix. The structure of DNA duplex strongly influences NIR and TF-stimulating activities. Homologous plant AP endonucleases lacking conserved cysteine residues stimulate DNA binding of the p50 subunit of NF-κB. APE1 acts synergistically with low-molecular-weight reducing agents on TFs. Finally, APE1 stimulates DNA binding of the redox-insensitive p50-C62S mutant protein. Electron microscopy imaging of APE1 complexes with DNA revealed preferential polymerization of APE1 on the gapped and intrinsically curved DNA duplexes. Molecular modeling offers a structural explanation how full-length APE1 can oligomerize on DNA. In conclusion, we propose that DNA-directed APE1 oligomerization can be regarded as a substitute for diffusion of APE1 along the DNA contour to probe for anisotropic flexibility. APE1 oligomers exacerbate pre-existing distortions in DNA and enable both NIR activity and DNA binding by TFs regardless of their oxidation state.
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Affiliation(s)
- Milena Bazlekowa-Karaban
- Groupe «Réparation de l'ADN», Equipe Labellisée par la Ligue Nationale Contre le Cancer, CNRS UMR8200, Université Paris-Sud, Université Paris-Saclay, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France; Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | - Paulina Prorok
- Groupe «Réparation de l'ADN», Equipe Labellisée par la Ligue Nationale Contre le Cancer, CNRS UMR8200, Université Paris-Sud, Université Paris-Saclay, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France; Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Human Genetics, UMR 9002, CNRS - University of Montpellier, Replication and Genome Dynamics, 141 rue de la Cardonille, 34396, Montpellier, France
| | - Sonia Baconnais
- CNRS UMR8126, Université Paris-Sud, Université Paris-Saclay, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France
| | - Sabira Taipakova
- Department of Molecular Biology and Genetics, Faculty of Biology, al-Farabi Kazakh National University, 0530040, Almaty, Kazakhstan
| | - Zhiger Akishev
- Department of Molecular Biology and Genetics, Faculty of Biology, al-Farabi Kazakh National University, 0530040, Almaty, Kazakhstan
| | - Dominika Zembrzuska
- Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | - Alexander V Popov
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia
| | - Anton V Endutkin
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia
| | - Regina Groisman
- Groupe «Réparation de l'ADN», Equipe Labellisée par la Ligue Nationale Contre le Cancer, CNRS UMR8200, Université Paris-Sud, Université Paris-Saclay, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France
| | - Alexander A Ishchenko
- Groupe «Réparation de l'ADN», Equipe Labellisée par la Ligue Nationale Contre le Cancer, CNRS UMR8200, Université Paris-Sud, Université Paris-Saclay, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France
| | - Bakhyt T Matkarimov
- National laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan
| | - Amangeldy Bissenbaev
- Department of Molecular Biology and Genetics, Faculty of Biology, al-Farabi Kazakh National University, 0530040, Almaty, Kazakhstan
| | - Eric Le Cam
- CNRS UMR8126, Université Paris-Sud, Université Paris-Saclay, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France
| | - Dmitry O Zharkov
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia
| | - Barbara Tudek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | - Murat Saparbaev
- Groupe «Réparation de l'ADN», Equipe Labellisée par la Ligue Nationale Contre le Cancer, CNRS UMR8200, Université Paris-Sud, Université Paris-Saclay, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France.
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Luzhin AV, Flyamer IM, Khrameeva EE, Ulianov SV, Razin SV, Gavrilov AA. Quantitative differences in TAD border strength underly the TAD hierarchy in Drosophila chromosomes. J Cell Biochem 2018; 120:4494-4503. [PMID: 30260021 DOI: 10.1002/jcb.27737] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 09/30/2018] [Indexed: 12/19/2022]
Abstract
Chromosomes in many organisms, including Drosophila and mammals, are folded into topologically associating domains (TADs). Increasing evidence suggests that TAD folding is hierarchical, wherein subdomains combine to form larger superdomains, instead of a sequence of nonoverlapping domains. Here, we studied the hierarchical structure of TADs in Drosophila. We show that the boundaries of TADs of different hierarchical levels are characterized by the presence of different portions of active chromatin, but do not vary in the binding of architectural proteins, such as CCCTC binding factor or cohesin. The apparent hierarchy of TADs in Drosophila chromosomes is not likely to have functional importance but rather reflects various options of long-range chromatin folding directed by the distribution of active and inactive chromatin segments and may represent population average.
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Affiliation(s)
- Artem V Luzhin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Ilya M Flyamer
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Ekaterina E Khrameeva
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia.,Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Sergey V Ulianov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,Department of Molecular Biology, Lomonosov Moscow State University, Russia
| | - Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,Department of Molecular Biology, Lomonosov Moscow State University, Russia
| | - Alexey A Gavrilov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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Pellestor F, Gatinois V. Chromothripsis, a credible chromosomal mechanism in evolutionary process. Chromosoma 2018; 128:1-6. [DOI: 10.1007/s00412-018-0679-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 01/17/2023]
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Razin SV. Structural-Functional Organization of the Eukaryotic Cell Nucleus and Transcription Regulation: Introduction to This Special Issue of Biochemistry (Moscow). BIOCHEMISTRY (MOSCOW) 2018; 83:299-301. [PMID: 29626917 DOI: 10.1134/s0006297918040016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This issue of Biochemistry (Moscow) is devoted to the cell nucleus and mechanisms of transcription regulation. Over the years, biochemical processes in the cell nucleus have been studied in isolation, outside the context of their spatial organization. Now it is clear that segregation of functional processes within a compartmentalized cell nucleus is very important for the implementation of basic genetic processes. The functional compartmentalization of the cell nucleus is closely related to the spatial organization of the genome, which in turn plays a key role in the operation of epigenetic mechanisms. In this issue of Biochemistry (Moscow), we present a selection of review articles covering the functional architecture of the eukaryotic cell nucleus, the mechanisms of genome folding, the role of stochastic processes in establishing 3D architecture of the genome, and the impact of genome spatial organization on transcription regulation.
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Affiliation(s)
- S V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
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Cremer T, Cremer M, Cremer C. The 4D Nucleome: Genome Compartmentalization in an Evolutionary Context. BIOCHEMISTRY (MOSCOW) 2018; 83:313-325. [PMID: 29626919 DOI: 10.1134/s000629791804003x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
4D nucleome research aims to understand the impact of nuclear organization in space and time on nuclear functions, such as gene expression patterns, chromatin replication, and the maintenance of genome integrity. In this review we describe evidence that the origin of 4D genome compartmentalization can be traced back to the prokaryotic world. In cell nuclei of animals and plants chromosomes occupy distinct territories, built up from ~1 Mb chromatin domains, which in turn are composed of smaller chromatin subdomains and also form larger chromatin domain clusters. Microscopic evidence for this higher order chromatin landscape was strengthened by chromosome conformation capture studies, in particular Hi-C. This approach demonstrated ~1 Mb sized, topologically associating domains in mammalian cell nuclei separated by boundaries. Mutations, which destroy boundaries, can result in developmental disorders and cancer. Nucleosomes appeared first as tetramers in the Archaea kingdom and later evolved to octamers built up each from two H2A, two H2B, two H3, and two H4 proteins. Notably, nucleosomes were lost during the evolution of the Dinoflagellata phylum. Dinoflagellate chromosomes remain condensed during the entire cell cycle, but their chromosome architecture differs radically from the architecture of other eukaryotes. In summary, the conservation of fundamental features of higher order chromatin arrangements throughout the evolution of metazoan animals suggests the existence of conserved, but still unknown mechanism(s) controlling this architecture. Notwithstanding this conservation, a comparison of metazoans and protists also demonstrates species-specific structural and functional features of nuclear organization.
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Affiliation(s)
- T Cremer
- Biocenter, Department of Biology II, Ludwig Maximilian University (LMU), Munich, Germany.
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The 10-nm chromatin fiber and its relationship to interphase chromosome organization. Biochem Soc Trans 2017; 46:67-76. [PMID: 29263138 PMCID: PMC5818668 DOI: 10.1042/bst20170101] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/25/2017] [Accepted: 10/27/2017] [Indexed: 01/09/2023]
Abstract
A chromosome is a single long DNA molecule assembled along its length with nucleosomes and proteins. During interphase, a mammalian chromosome exists as a highly organized supramolecular globule in the nucleus. Here, we discuss new insights into how genomic DNA is packaged and organized within interphase chromosomes. Our emphasis is on the structural principles that underlie chromosome organization, with a particular focus on the intrinsic contributions of the 10-nm chromatin fiber, but not the regular 30-nm fiber. We hypothesize that the hierarchical globular organization of an interphase chromosome is fundamentally established by the self-interacting properties of a 10-nm zig-zag array of nucleosomes, while histone post-translational modifications, histone variants, and chromatin-associated proteins serve to mold generic chromatin domains into specific structural and functional entities.
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Razin SV, Ulianov SV. Gene functioning and storage within a folded genome. Cell Mol Biol Lett 2017; 22:18. [PMID: 28861108 PMCID: PMC5575855 DOI: 10.1186/s11658-017-0050-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 08/24/2017] [Indexed: 01/28/2023] Open
Abstract
In mammals, genomic DNA that is roughly 2 m long is folded to fit the size of the cell nucleus that has a diameter of about 10 μm. The folding of genomic DNA is mediated via assembly of DNA-protein complex, chromatin. In addition to the reduction of genomic DNA linear dimensions, the assembly of chromatin allows to discriminate and to mark active (transcribed) and repressed (non-transcribed) genes. Consequently, epigenetic regulation of gene expression occurs at the level of DNA packaging in chromatin. Taking into account the increasing attention of scientific community toward epigenetic systems of gene regulation, it is very important to understand how DNA folding in chromatin is related to gene activity. For many years the hierarchical model of DNA folding was the most popular. It was assumed that nucleosome fiber (10-nm fiber) is folded into 30-nm fiber and further on into chromatin loops attached to a nuclear/chromosome scaffold. Recent studies have demonstrated that there is much less regularity in chromatin folding within the cell nucleus. The very existence of 30-nm chromatin fibers in living cells was questioned. On the other hand, it was found that chromosomes are partitioned into self-interacting spatial domains that restrict the area of enhancers action. Thus, TADs can be considered as structural-functional domains of the chromosomes. Here we discuss the modern view of DNA packaging within the cell nucleus in relation to the regulation of gene expression. Special attention is paid to the possible mechanisms of the chromatin fiber self-assembly into TADs. We discuss the model postulating that partitioning of the chromosome into TADs is determined by the distribution of active and inactive chromatin segments along the chromosome. This article was specially invited by the editors and represents work by leading researchers.
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Affiliation(s)
- Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, 119334 Moscow, Russia.,Lomonosov Moscow State University, Biological Faculty, Leninskie Gory 1, building 12, 119192 Moscow, Russia
| | - Sergey V Ulianov
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, 119334 Moscow, Russia.,Lomonosov Moscow State University, Biological Faculty, Leninskie Gory 1, building 12, 119192 Moscow, Russia
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