1
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Zhang M, Ehmann ME, Matukumalli S, Boob AG, Gilbert DM, Zhao H. SHIELD: a platform for high-throughput screening of barrier-type DNA elements in human cells. Nat Commun 2023; 14:5616. [PMID: 37699958 PMCID: PMC10497619 DOI: 10.1038/s41467-023-41468-3] [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: 10/06/2022] [Accepted: 09/04/2023] [Indexed: 09/14/2023] Open
Abstract
Chromatin boundary elements contribute to the partitioning of mammalian genomes into topological domains to regulate gene expression. Certain boundary elements are adopted as DNA insulators for safe and stable transgene expression in mammalian cells. These elements, however, are ill-defined and less characterized in the non-coding genome, partially due to the lack of a platform to readily evaluate boundary-associated activities of putative DNA sequences. Here we report SHIELD (Site-specific Heterochromatin Insertion of Elements at Lamina-associated Domains), a platform tailored for the high-throughput screening of barrier-type DNA elements in human cells. SHIELD takes advantage of the high specificity of serine integrase at heterochromatin, and exploits the natural heterochromatin spreading inside lamina-associated domains (LADs) for the discovery of potent barrier elements. We adopt SHIELD to evaluate the barrier activity of 1000 DNA elements in a high-throughput manner and identify 8 candidates with barrier activities comparable to the core region of cHS4 element in human HCT116 cells. We anticipate SHIELD could facilitate the discovery of novel barrier DNA elements from the non-coding genome in human cells.
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Affiliation(s)
- Meng Zhang
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Mary Elisabeth Ehmann
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Srija Matukumalli
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Aashutosh Girish Boob
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - David M Gilbert
- San Diego Biomedical Research Institute, San Diego, CA, 92121, USA
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Chemistry, Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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2
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Pop RT, Pisante A, Nagy D, Martin PCN, Mikheeva L, Hayat A, Ficz G, Zabet NR. Identification of mammalian transcription factors that bind to inaccessible chromatin. Nucleic Acids Res 2023; 51:8480-8495. [PMID: 37486787 PMCID: PMC10484684 DOI: 10.1093/nar/gkad614] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/11/2023] [Indexed: 07/26/2023] Open
Abstract
Transcription factors (TFs) are proteins that affect gene expression by binding to regulatory regions of DNA in a sequence specific manner. The binding of TFs to DNA is controlled by many factors, including the DNA sequence, concentration of TF, chromatin accessibility and co-factors. Here, we systematically investigated the binding mechanism of hundreds of TFs by analysing ChIP-seq data with our explainable statistical model, ChIPanalyser. This tool uses as inputs the DNA sequence binding motif; the capacity to distinguish between strong and weak binding sites; the concentration of TF; and chromatin accessibility. We found that approximately one third of TFs are predicted to bind the genome in a DNA accessibility independent fashion, which includes TFs that can open the chromatin, their co-factors and TFs with similar motifs. Our model predicted this to be the case when the TF binds to its strongest binding regions in the genome, and only a small number of TFs have the capacity to bind dense chromatin at their weakest binding regions, such as CTCF, USF2 and CEBPB. Our study demonstrated that the binding of hundreds of human and mouse TFs is predicted by ChIPanalyser with high accuracy and showed that many TFs can bind dense chromatin.
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Affiliation(s)
- Romana T Pop
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, Oslo, Norway
| | - Alessandra Pisante
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - Dorka Nagy
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK
- National Heart and Lung Institute, Imperial College London, London SW3 6LY, UK
| | | | | | - Ateequllah Hayat
- Institute of Medical and Biomedical Education, St George's, University of London, Cranmer Terrace, Tooting SW17 0RE, London
| | - Gabriella Ficz
- Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, UK
| | - Nicolae Radu Zabet
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
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3
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Horvath RM, Sadowski I. Upstream Stimulatory Factors Regulate HIV-1 Latency and Are Required for Robust T Cell Activation. Viruses 2023; 15:1470. [PMID: 37515158 PMCID: PMC10384547 DOI: 10.3390/v15071470] [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: 04/27/2023] [Revised: 06/25/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
HIV-1 provirus expression is controlled by signaling pathways that are responsive to T cell receptor engagement, including those involving Ras and downstream protein kinases. The induction of transcription from the HIV-1 LTR in response to Ras signaling requires binding of the Ras-responsive element binding factor (RBF-2) to conserved cis elements flanking the enhancer region, designated RBE3 and RBE1. RBF-2 is composed minimally of the USF1, USF2, and TFII-I transcription factors. We recently determined that TFII-I regulates transcriptional elongation from the LTR through recruitment of the co-activator TRIM24. However, the function of USF1 and USF2 for this effect are uncharacterized. Here, we find that genetic deletion of USF2 but not USF1 in T cells inhibits HIV-1 expression. The loss of USF2 caused a reduction in expression of the USF1 protein, an effect that was not associated with decreased USF1 mRNA abundance. USF1 and USF2 were previously shown to exist predominately as heterodimers and to cooperatively regulate target genes. To examine cooperativity between these factors, we performed RNA-seq analysis of T cell lines bearing knockouts of the genes encoding these factors. In untreated cells, we found limited evidence of coordinated global gene regulation between USF1 and USF2. In contrast, we observed a high degree of genome-wide cooperative regulation of RNA expression between these factors in cells stimulated with the combination of PMA and ionomycin. In particular, we found that the deletion of USF1 or USF2 restricted T cell activation response. These observations indicate that USF2, but not USF1, is crucial for HIV-1 expression, while the combined function of these factors is required for a robust T cell inflammatory response.
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Affiliation(s)
- Riley M Horvath
- Molecular Epigenetics Group, Department of Biochemistry and Molecular Biology, LSI, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Ivan Sadowski
- Molecular Epigenetics Group, Department of Biochemistry and Molecular Biology, LSI, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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4
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Cosenza G, Martin P, Garro G, Gallo D, Auzino B, Ciampolini R, Pauciullo A. A novel allelic donkey β-lactogobulin I protein isoform generated by a non-AUG translation initiation codon is associated with a nonsynonymous SNP. J Dairy Sci 2023; 106:4158-4170. [PMID: 37080792 DOI: 10.3168/jds.2022-22598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 12/17/2022] [Indexed: 04/22/2023]
Abstract
β-Lactoglobulin I (β-LG I) is one of the most important whey proteins in donkey milk. However, to our knowledge, there has been no study focusing on the full nucleotide sequences of this gene (BLG I). Current investigation of donkey BLG I gene is very limited with only 2 variants (A and B) characterized so far at the protein level. Recently, a new β-LG I variant, with a significantly higher mass (+1,915 Da) than known variants has been detected. In this study, we report the whole nucleotide sequence of the BLG I gene from 2 donkeys, whose milk samples are characterized by the β-LG I SDS-PAGE band with a normal electrophoretic mobility (18,514.25 Da, β-LG I B1 form) the first, and by the presence of a unique β-LG I band with a higher electrophoretic mobility (20,428.5 Da, β-LG I D form) the latter. A high genetic variability was found all over the 2 sequenced BLG I alleles. In particular, 16 polymorphic sites were found in introns, one in the 5' flanking region, 3 SNPs in the 5' untranslated region and one SNP in the coding region (g.458G > A) located at the 40th nucleotide of exon 2 and responsible for the AA substitutions p.Asp28 > Asn in the mature protein. Two SNPs (g.920-922CAC > TGT and g.1871G/A) were genotyped in 93 donkeys of 2 Italian breeds (60 Ragusana and 33 Amiatina, respectively) and the overall frequencies of g.920-922CAC and g.1871A were 0.3065 and 0.043, respectively. Only the rare allele g.1871A was observed to be associated with the slower migrating β-LG I. Considering this genetic diversity and those found in the database, it was possible to deduce at least 5 different alleles (BLG I A, B, B1, C, D) responsible for 4 potential β-LG I translations. Among these alleles, B1 and D are those characterized in the present research, with the D allele of real novel identification. Haplotype data analysis suggests an evolutionary pathway of donkey BLG I gene and a possible phylogenetic map is proposed. Analyses of mRNA secondary structure showed relevant changes in the structures, as consequence of the g.1871G > A polymorphism, that might be responsible for the recognition of an alternative initiation site providing an additional signal peptide. The extension of 19 AA sequence to the mature protein, corresponding to the canonical signal peptide with an additional alanine residue, is sufficient to provide the observed molecular weight of the slower migrating β-LG I encoded by the BLG I D allele.
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Affiliation(s)
- G Cosenza
- Department of Agricultural Sciences, University of Naples "Federico II," 80055 Portici (Na), Italy.
| | - P Martin
- Université Paris-Saclay, INRAE, MICALIS Institute, PAPPSO, 78350 Jouy-en-Josas, France
| | - G Garro
- Department of Agricultural Sciences, University of Naples "Federico II," 80055 Portici (Na), Italy
| | - D Gallo
- Department of Agricultural Sciences, University of Naples "Federico II," 80055 Portici (Na), Italy
| | - B Auzino
- Department of Veterinary Science, University of Pisa, 56100, Italy
| | - R Ciampolini
- Department of Veterinary Science, University of Pisa, 56100, Italy.
| | - A Pauciullo
- Department of Agriculture, Forest and Food Sciences, University of Torino, 10095 Grugliasco (TO), Italy
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5
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Nam AS, Dusaj N, Izzo F, Murali R, Myers RM, Mouhieddine TH, Sotelo J, Benbarche S, Waarts M, Gaiti F, Tahri S, Levine R, Abdel-Wahab O, Godley LA, Chaligne R, Ghobrial I, Landau DA. Single-cell multi-omics of human clonal hematopoiesis reveals that DNMT3A R882 mutations perturb early progenitor states through selective hypomethylation. Nat Genet 2022; 54:1514-1526. [PMID: 36138229 PMCID: PMC10068894 DOI: 10.1038/s41588-022-01179-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 07/29/2022] [Indexed: 12/13/2022]
Abstract
Somatic mutations in cancer genes have been detected in clonal expansions across healthy human tissue, including in clonal hematopoiesis. However, because mutated and wild-type cells are admixed, we have limited ability to link genotypes with phenotypes. To overcome this limitation, we leveraged multi-modality single-cell sequencing, capturing genotype, transcriptomes and methylomes in progenitors from individuals with DNMT3A R882 mutated clonal hematopoiesis. DNMT3A mutations result in myeloid over lymphoid bias, and an expansion of immature myeloid progenitors primed toward megakaryocytic-erythroid fate, with dysregulated expression of lineage and leukemia stem cell markers. Mutated DNMT3A leads to preferential hypomethylation of polycomb repressive complex 2 targets and a specific CpG flanking motif. Notably, the hypomethylation motif is enriched in binding motifs of key hematopoietic transcription factors, serving as a potential mechanistic link between DNMT3A mutations and aberrant transcriptional phenotypes. Thus, single-cell multi-omics paves the road to defining the downstream consequences of mutations that drive clonal mosaicism.
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Affiliation(s)
- Anna S Nam
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, USA
- New York Genome Center, New York, NY, USA
| | - Neville Dusaj
- New York Genome Center, New York, NY, USA
- Division of Hematology and Medical Oncology, Department of Medicine and Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
- Tri-Institutional MD-PhD Program, Weill Cornell Medicine, Rockefeller University, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Franco Izzo
- New York Genome Center, New York, NY, USA
- Division of Hematology and Medical Oncology, Department of Medicine and Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Rekha Murali
- New York Genome Center, New York, NY, USA
- Division of Hematology and Medical Oncology, Department of Medicine and Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Robert M Myers
- New York Genome Center, New York, NY, USA
- Division of Hematology and Medical Oncology, Department of Medicine and Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
- Tri-Institutional MD-PhD Program, Weill Cornell Medicine, Rockefeller University, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Tarek H Mouhieddine
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Jesus Sotelo
- New York Genome Center, New York, NY, USA
- Division of Hematology and Medical Oncology, Department of Medicine and Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Salima Benbarche
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Michael Waarts
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Federico Gaiti
- New York Genome Center, New York, NY, USA
- Division of Hematology and Medical Oncology, Department of Medicine and Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Sabrin Tahri
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Ross Levine
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Omar Abdel-Wahab
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Lucy A Godley
- Section of Hematology/Oncology, Departments of Medicine and Human Genetics, The University of Chicago, Chicago, IL, USA
| | - Ronan Chaligne
- New York Genome Center, New York, NY, USA
- Division of Hematology and Medical Oncology, Department of Medicine and Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Irene Ghobrial
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
| | - Dan A Landau
- New York Genome Center, New York, NY, USA.
- Division of Hematology and Medical Oncology, Department of Medicine and Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA.
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA.
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6
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Sizer RE, Chahid N, Butterfield SP, Donze D, Bryant NJ, White RJ. TFIIIC-based chromatin insulators through eukaryotic evolution. Gene X 2022; 835:146533. [PMID: 35623477 DOI: 10.1016/j.gene.2022.146533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 04/19/2022] [Accepted: 04/29/2022] [Indexed: 11/04/2022] Open
Abstract
Eukaryotic chromosomes are divided into domains with distinct structural and functional properties, such as differing levels of chromatin compaction and gene transcription. Domains of relatively compact chromatin and minimal transcription are termed heterochromatic, whereas euchromatin is more open and actively transcribed. Insulators separate these domains and maintain their distinct features. Disruption of insulators can cause diseases such as cancer. Many insulators contain tRNA genes (tDNAs), examples of which have been shown to block the spread of activating or silencing activities. This characteristic of specific tDNAs is conserved through evolution, such that human tDNAs can serve as barriers to the spread of silencing in fission yeast. Here we demonstrate that tDNAs from the methylotrophic fungus Pichia pastoris can function effectively as insulators in distantly-related budding yeast. Key to the function of tDNAs as insulators is TFIIIC, a transcription factor that is also required for their expression. TFIIIC binds additional loci besides tDNAs, some of which have insulator activity. Although the mechanistic basis of TFIIIC-based insulation has been studied extensively in yeast, it is largely uncharacterized in metazoa. Utilising publicly-available genome-wide ChIP-seq data, we consider the extent to which mechanisms conserved from yeast to man may suffice to allow efficient insulation by TFIIIC in the more challenging chromatin environments of metazoa and suggest features that may have been acquired during evolution to cope with new challenges. We demonstrate the widespread presence at human tDNAs of USF1, a transcription factor with well-established barrier activity in vertebrates. We predict that tDNA-based insulators in higher organisms have evolved through incorporation of modules, such as binding sites for factors like USF1 and CTCF that are absent from yeasts, thereby strengthening function and providing opportunities for regulation between cell types.
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Affiliation(s)
- Rebecca E Sizer
- Department of Biology, The University of York, York YO10 5DD, UK
| | - Nisreen Chahid
- Department of Biology, The University of York, York YO10 5DD, UK
| | | | - David Donze
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Nia J Bryant
- Department of Biology, The University of York, York YO10 5DD, UK
| | - Robert J White
- Department of Biology, The University of York, York YO10 5DD, UK.
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7
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Beacon TH, Delcuve GP, López C, Nardocci G, Kovalchuk I, van Wijnen AJ, Davie JR. The dynamic broad epigenetic (H3K4me3, H3K27ac) domain as a mark of essential genes. Clin Epigenetics 2021; 13:138. [PMID: 34238359 PMCID: PMC8264473 DOI: 10.1186/s13148-021-01126-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/30/2021] [Indexed: 02/06/2023] Open
Abstract
Transcriptionally active chromatin is marked by tri-methylation of histone H3 at lysine 4 (H3K4me3) located after first exons and around transcription start sites. This epigenetic mark is typically restricted to narrow regions at the 5`end of the gene body, though a small subset of genes have a broad H3K4me3 domain which extensively covers the coding region. Although most studies focus on the H3K4me3 mark, the broad H3K4me3 domain is associated with a plethora of histone modifications (e.g., H3 acetylated at K27) and is therein termed broad epigenetic domain. Genes marked with the broad epigenetic domain are involved in cell identity and essential cell functions and have clinical potential as biomarkers for patient stratification. Reducing expression of genes with the broad epigenetic domain may increase the metastatic potential of cancer cells. Enhancers and super-enhancers interact with the broad epigenetic domain marked genes forming a hub of interactions involving nucleosome-depleted regions. Together, the regulatory elements coalesce with transcription factors, chromatin modifying/remodeling enzymes, coactivators, and the Mediator and/or Integrator complex into a transcription factory which may be analogous to a liquid–liquid phase-separated condensate. The broad epigenetic domain has a dynamic chromatin structure which supports frequent transcription bursts. In this review, we present the current knowledge of broad epigenetic domains.
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Affiliation(s)
- Tasnim H Beacon
- CancerCare Manitoba Research Institute, CancerCare Manitoba, Winnipeg, MB, R3E 0V9, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, 745 Bannatyne Avenue, Room 333A, Winnipeg, MB, Canada
| | - Geneviève P Delcuve
- Department of Biochemistry and Medical Genetics, University of Manitoba, 745 Bannatyne Avenue, Room 333A, Winnipeg, MB, Canada
| | - Camila López
- CancerCare Manitoba Research Institute, CancerCare Manitoba, Winnipeg, MB, R3E 0V9, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, 745 Bannatyne Avenue, Room 333A, Winnipeg, MB, Canada
| | - Gino Nardocci
- Faculty of Medicine, Universidad de Los Andes, Santiago, Chile.,Molecular Biology and Bioinformatics Lab, Program in Molecular Biology and Bioinformatics, Center for Biomedical Research and Innovation (CIIB), Universidad de Los Andes, Santiago, Chile
| | - Igor Kovalchuk
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada
| | - Andre J van Wijnen
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA.,Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - James R Davie
- CancerCare Manitoba Research Institute, CancerCare Manitoba, Winnipeg, MB, R3E 0V9, Canada. .,Department of Biochemistry and Medical Genetics, University of Manitoba, 745 Bannatyne Avenue, Room 333A, Winnipeg, MB, Canada.
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8
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Parental nucleosome segregation and the inheritance of cellular identity. Nat Rev Genet 2021; 22:379-392. [PMID: 33500558 DOI: 10.1038/s41576-020-00312-w] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2020] [Indexed: 12/20/2022]
Abstract
Gene expression programmes conferring cellular identity are achieved through the organization of chromatin structures that either facilitate or impede transcription. Among the key determinants of chromatin organization are the histone modifications that correlate with a given transcriptional status and chromatin state. Until recently, the details for the segregation of nucleosomes on DNA replication and their implications in re-establishing heritable chromatin domains remained unclear. Here, we review recent findings detailing the local segregation of parental nucleosomes and highlight important advances as to how histone methyltransferases associated with the establishment of repressive chromatin domains facilitate epigenetic inheritance.
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9
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Yeung BHY, Huang J, An SS, Solway J, Mitzner W, Tang WY. Role of Isocitrate Dehydrogenase 2 on DNA Hydroxymethylation in Human Airway Smooth Muscle Cells. Am J Respir Cell Mol Biol 2020; 63:36-45. [PMID: 32150688 DOI: 10.1165/rcmb.2019-0323oc] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Global DNA hydroxymethylation mediated by the TET (ten-eleven translocation) enzyme was induced in allergen-induced airway hyperresponsiveness in mouse lung tissues and specifically in isolated airway smooth muscle (ASM) cells. TET is an α-ketoglutarate (α-KG)-dependent enzyme, and the production of α-KG is catalyzed by IDH (isocitrate dehydrogenase). However, the role of IDH in the regulation of DNA hydroxymethylation in ASM cells is unknown. In comparison with nonasthmatic cells, asthmatic ASM cells exhibited higher TET activity and IDH2 (but not IDH-1 or IDH-3) gene expression levels. We modified the expression of IDH2 in ASM cells from humans with asthma by siRNA and examined the α-KG levels, TET activity, global DNA hydroxymethylation, cell proliferation, and expression of ASM phenotypic genes. Inhibition of IDH2 in asthmatic ASM cells decreased the α-KG levels, TET activity, and global DNA hydroxymethylation, and reversed the aberrant ASM phenotypes (including decreased cell proliferation and ASM phenotypic gene expression). Specifically, asthmatic cells transfected with siRNA against IDH2 showed decreased 5hmC (5-hydroxymethylcytosine) levels at the TGFB2 (transforming growth factor-β2) promoter determined by oxidative bisulfite sequencing. Taken together, our findings reveal that IDH2 plays an important role in the epigenetic regulation of ASM phenotypic changes in asthmatic ASM cells, suggesting that IDH2 is a potential therapeutic target for reversing the abnormal phenotypes seen in asthma.
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Affiliation(s)
- Bonnie H Y Yeung
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Jessie Huang
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,Center for Regenerative Medicine, Boston University School of Medicine, Boston, Massachusetts
| | - Steven S An
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, The State University of New Jersey, Piscataway, New Jersey.,Rutgers Institute for Translational Medicine and Science, New Brunswick, New Jersey
| | - Julian Solway
- Department of Medicine, University of Chicago, Chicago, Illinois; and
| | - Wayne Mitzner
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Wan-Yee Tang
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania
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10
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Carleton JB, Ginley-Hidinger M, Berrett KC, Layer RM, Quinlan AR, Gertz J. Regulatory sharing between estrogen receptor α bound enhancers. Nucleic Acids Res 2020; 48:6597-6610. [PMID: 32479598 PMCID: PMC7337896 DOI: 10.1093/nar/gkaa454] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/15/2020] [Accepted: 05/18/2020] [Indexed: 12/28/2022] Open
Abstract
The human genome encodes an order of magnitude more gene expression enhancers than promoters, suggesting that most genes are regulated by the combined action of multiple enhancers. We have previously shown that neighboring estrogen-responsive enhancers exhibit complex synergistic contributions to the production of an estrogenic transcriptional response. Here we sought to determine the molecular underpinnings of this enhancer cooperativity. We generated genetic deletions of four estrogen receptor α (ER) bound enhancers that regulate two genes and found that enhancers containing full estrogen response element (ERE) motifs control ER binding at neighboring sites, while enhancers with pre-existing histone acetylation/accessibility confer a permissible chromatin environment to the neighboring enhancers. Genome engineering revealed that two enhancers with half EREs could not compensate for the lack of a full ERE site within the cluster. In contrast, two enhancers with full EREs produced a transcriptional response greater than the wild-type locus. By swapping genomic sequences, we found that the genomic location of a full ERE strongly influences enhancer activity. Our results lead to a model in which a full ERE is required for ER recruitment, but the presence of a pre-existing permissible chromatin environment can also be needed for estrogen-driven gene regulation to occur.
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Affiliation(s)
- Julia B Carleton
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.,Department of Oncological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Matthew Ginley-Hidinger
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Kristofer C Berrett
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.,Department of Oncological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Ryan M Layer
- BioFrontiers Institute, University of Colorado, Boulder, CO, USA.,Department of Computer Science, University of Colorado, Boulder, CO, USA
| | - Aaron R Quinlan
- Departments of Human Genetics and Biomedical Informatics, University of Utah, Salt Lake City, UT, USA
| | - Jason Gertz
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.,Department of Oncological Sciences, University of Utah, Salt Lake City, UT, USA
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11
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Beacon TH, Xu W, Davie JR. Genomic landscape of transcriptionally active histone arginine methylation marks, H3R2me2s and H4R3me2a, relative to nucleosome depleted regions. Gene 2020; 742:144593. [DOI: 10.1016/j.gene.2020.144593] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/10/2020] [Accepted: 03/14/2020] [Indexed: 02/06/2023]
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12
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Hua ZY, Hansen JN, He M, Dai SK, Choi Y, Fulton MD, Lloyd SM, Szemes M, Sen J, Ding HF, Angelastro JM, Fei X, Li HP, Wu CR, Yang SY, Malik K, Bao X, George Zheng Y, Liu CM, Schor NF, Li ZJ, Li XG. PRMT1 promotes neuroblastoma cell survival through ATF5. Oncogenesis 2020; 9:50. [PMID: 32415090 PMCID: PMC7229216 DOI: 10.1038/s41389-020-0237-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 02/07/2023] Open
Abstract
Aberrant expression of protein arginine methyltransferases (PRMTs) has been implicated in a number of cancers, making PRMTs potential therapeutic targets. But it remains not well understood how PRMTs impact specific oncogenic pathways. We previously identified PRMTs as important regulators of cell growth in neuroblastoma, a deadly childhood tumor of the sympathetic nervous system. Here, we demonstrate a critical role for PRMT1 in neuroblastoma cell survival. PRMT1 depletion decreased the ability of murine neuroblastoma sphere cells to grow and form spheres, and suppressed proliferation and induced apoptosis of human neuroblastoma cells. Mechanistic studies reveal the prosurvival factor, activating transcription factor 5 (ATF5) as a downstream effector of PRMT1-mediated survival signaling. Furthermore, a diamidine class of PRMT1 inhibitors exhibited anti-neuroblastoma efficacy both in vitro and in vivo. Importantly, overexpression of ATF5 rescued cell apoptosis triggered by PRMT1 inhibition genetically or pharmacologically. Taken together, our findings shed new insights into PRMT1 signaling pathway, and provide evidence for PRMT1 as an actionable therapeutic target in neuroblastoma.
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Affiliation(s)
- Zhong-Yan Hua
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
- Liaoning Key Laboratory of Research and Application of Animal Models for Environmental and Metabolic Diseases, Medical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Jeanne N Hansen
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
- Department of Biology, Colgate University, Hamilton, NY, USA
| | - Miao He
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, China
| | - Shang-Kun Dai
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yoonjung Choi
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Melody D Fulton
- Department of Pharmaceutical and Biochemical Sciences, College of Pharmacy, University of Georgia, Athens, GA, USA
| | - Sarah M Lloyd
- Departments of Molecular Biosciences and Dermatology, Northwestern University, Evanston, IL, USA
| | - Marianna Szemes
- Cancer Epigenetics Laboratory, School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Ji Sen
- State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Han-Fei Ding
- The Georgia Cancer Center, Augusta University, Augusta, GA, USA
| | - James M Angelastro
- Department of Molecular Biosciences, University of California, Davis School of Veterinary Medicine, Davis, CA, USA
| | - Xiang Fei
- Shengjing Hospital of China Medical University, Shenyang, China
| | - Hui-Ping Li
- Department of Pulmonary and Critical Care Medicine, Shenzhen Renmin Hospital, Shenzhen, China
| | - Chao-Ran Wu
- Department of Anesthesiology, Shenzhen Renmin Hospital, Shenzhen, China
| | - Sheng-Yong Yang
- State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Karim Malik
- Cancer Epigenetics Laboratory, School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Xiaomin Bao
- Departments of Molecular Biosciences and Dermatology, Northwestern University, Evanston, IL, USA
| | - Y George Zheng
- Department of Pharmaceutical and Biochemical Sciences, College of Pharmacy, University of Georgia, Athens, GA, USA
| | - Chang-Mei Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Nina F Schor
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
- National Institute of Neurological Disorders & Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Zhi-Jie Li
- Liaoning Key Laboratory of Research and Application of Animal Models for Environmental and Metabolic Diseases, Medical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xing-Guo Li
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
- Wilmot Cancer Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
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13
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Taghizadeh E, Mirzaei F, Jalilian N, Ghayour Mobarhan M, Ferns GA, Pasdar A. A novel mutation in
USF1
gene is associated with familial combined hyperlipidemia. IUBMB Life 2019; 72:616-623. [DOI: 10.1002/iub.2186] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 10/01/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Eskandar Taghizadeh
- Department of Medical Genetics, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
- Cellular and Molecular Research CenterYasuj University of Medical Sciences Yasuj Iran
| | - Farzaneh Mirzaei
- Department of Medical Genetics, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
| | - Nazanin Jalilian
- Department of Clinical biochemistry, School of MedicineKermanshah University of Medical Sciences Kermanshah Iran
| | - Majid Ghayour Mobarhan
- Metabolic Syndrome Research Centre, School of MedicineMashhad University of Medical Sciences Mashhad Iran
| | - Gordon A. Ferns
- Department of Medical EducationBrighton and Sussex Medical School Perso Falmer Brighton UK
| | - Alireza Pasdar
- Department of Medical Genetics, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
- Medical Genetics Research Centre, Faculty of MedicineMashhad University of Medical Sciences Mashhad Iran
- Division of Applied Medicine, Medical School, University of Aberdeen Foresterhill Aberdeen UK
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14
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Bazov I, Sarkisyan D, Kononenko O, Watanabe H, Taqi MM, Stålhandske L, Verbeek DS, Mulder J, Rajkowska G, Sheedy D, Kril J, Sun X, Syvänen AC, Yakovleva T, Bakalkin G. Neuronal Expression of Opioid Gene is Controlled by Dual Epigenetic and Transcriptional Mechanism in Human Brain. Cereb Cortex 2019; 28:3129-3142. [PMID: 28968778 DOI: 10.1093/cercor/bhx181] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Indexed: 12/13/2022] Open
Abstract
Molecular mechanisms that define patterns of neuropeptide expression are essential for the formation and rewiring of neural circuits. The prodynorphin gene (PDYN) gives rise to dynorphin opioid peptides mediating depression and substance dependence. We here demonstrated that PDYN is expressed in neurons in human dorsolateral prefrontal cortex (dlPFC), and identified neuronal differentially methylated region in PDYN locus framed by CCCTC-binding factor binding sites. A short, nucleosome size human-specific promoter CpG island (CGI), a core of this region may serve as a regulatory module, which is hypomethylated in neurons, enriched in 5-hydroxymethylcytosine, and targeted by USF2, a methylation-sensitive E-box transcription factor (TF). USF2 activates PDYN transcription in model systems, and binds to nonmethylated CGI in dlPFC. USF2 and PDYN expression is correlated, and USF2 and PDYN proteins are co-localized in dlPFC. Segregation of activatory TF and repressive CGI methylation may ensure contrasting PDYN expression in neurons and glia in human brain.
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Affiliation(s)
- Igor Bazov
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Daniil Sarkisyan
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Olga Kononenko
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Hiroyuki Watanabe
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Mumtaz Malik Taqi
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden.,Faculty of Medicine, NORMENT, University of Oslo, Oslo, Norway
| | - Lada Stålhandske
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Dineke S Verbeek
- Department of Genetics, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands
| | - Jan Mulder
- Department of Neuroscience, Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden
| | - Grazyna Rajkowska
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA
| | - Donna Sheedy
- Discipline of Pathology, Sydney Medical School, University of Sydney, Sydney NSW, Australia
| | - Jillian Kril
- Discipline of Pathology, Sydney Medical School, University of Sydney, Sydney NSW, Australia
| | - Xueguang Sun
- Zymo Research Corporation, 17062 Murphy Avenue, Irvine, CA, USA.,Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Ann-Christine Syvänen
- Department of Medical Sciences, Molecular Medicine and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Tatiana Yakovleva
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Georgy Bakalkin
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
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15
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Skipper KA, Hollensen AK, Antoniou MN, Mikkelsen JG. Sustained transgene expression from sleeping beauty DNA transposons containing a core fragment of the HNRPA2B1-CBX3 ubiquitous chromatin opening element (UCOE). BMC Biotechnol 2019; 19:75. [PMID: 31706316 PMCID: PMC6842454 DOI: 10.1186/s12896-019-0570-2] [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: 06/03/2019] [Accepted: 10/15/2019] [Indexed: 12/22/2022] Open
Abstract
Background DNA transposon-based vectors are effective nonviral tools for gene therapy and genetic engineering of cells. However, promoter DNA methylation and a near-random integration profile, which can result in transgene integration into heterochromatin, renders such vectors vulnerable to transcriptional repression. Therefore, to secure persistent transgene expression it may be necessary to protect transposon-embedded transgenes with anti-transcriptional silencing elements. Results We compare four different protective strategies in CHO-K1 cells. Our findings show robust protection from silencing of transgene cassettes mediated by the ubiquitous chromatin-opening element (UCOE) derived from the HNRPA2B1-CBX3 locus. Using a bioinformatic approach, we define a shorter HNRPA2B1-CBX3 UCOE core fragment and demonstrate that this can robustly maintain transgene expression after extended passaging of CHO-K1 cells carrying DNA transposon vectors equipped with this protective feature. Conclusions Our findings contribute to the understanding of the mechanism of HNRPA2B1-CBX3 UCOE-based transgene protection and support the use of a correctly oriented core fragment of this UCOE for DNA transposon vector-based production of recombinant proteins in CHO-K1 cells.
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Affiliation(s)
| | - Anne Kruse Hollensen
- Department of Biomedicine, HEALTH, Aarhus University, DK- 8000, Aarhus C, Denmark.,Department of Molecular Biology and Genetics, Science and Technology, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Michael N Antoniou
- Gene Expression and Therapy Group, King's College London, Faculty of Life Sciences & Medicine, Department of Medical and Molecular Genetics, 8th Floor Tower Wing, Guy's Hospital, London, SE1 9RT, UK
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16
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Rozov SM, Deineko EV. Strategies for Optimizing Recombinant Protein Synthesis in Plant Cells: Classical Approaches and New Directions. Mol Biol 2019. [DOI: 10.1134/s0026893319020146] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Epigenomic analysis reveals DNA motifs regulating histone modifications in human and mouse. Proc Natl Acad Sci U S A 2019; 116:3668-3677. [PMID: 30755522 DOI: 10.1073/pnas.1813565116] [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] [Indexed: 11/18/2022] Open
Abstract
Histones are modified by enzymes that act in a locus, cell-type, and developmental stage-specific manner. The recruitment of enzymes to chromatin is regulated at multiple levels, including interaction with sequence-specific DNA-binding factors. However, the DNA-binding specificity of the regulatory factors that orchestrate specific histone modifications has not been broadly mapped. We have analyzed 6 histone marks (H3K4me1, H3K4me3, H3K27ac, H3K27me3, K3H9me3, H3K36me3) across 121 human cell types and tissues from the NIH Roadmap Epigenomics Project as well as 8 histone marks (with addition of H3K4me2 and H3K9ac) from the mouse ENCODE Consortium. We have identified 361 and 369 DNA motifs in human and mouse, respectively, that are the most predictive of each histone mark. Interestingly, 107 human motifs are conserved between the two species. In human embryonic cell line H1, we mutated only the found DNA motifs at particular loci and the significant reduction of H3K27ac levels validated the regulatory roles of the perturbed motifs. The functionality of these motifs was also supported by the evidence that histone-associated motifs, especially H3K4me3 motifs, significantly overlap with the expression of quantitative trait loci SNPs in cancer patients more than the known and random motifs. Furthermore, we observed possible feedbacks to control chromatin dynamics as the found motifs appear in the promoters or enhancers associated with various histone modification enzymes. These results pave the way toward revealing the molecular mechanisms of epigenetic events, such as histone modification dynamics and epigenetic priming.
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18
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Tsukamoto D, Ito M, Takamatsu N. Epigenetic regulation of hibernation-associated HP-20 and HP-27 gene transcription in chipmunk liver. Biochem Biophys Res Commun 2018; 495:1758-1765. [PMID: 29233692 DOI: 10.1016/j.bbrc.2017.12.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 12/08/2017] [Indexed: 11/19/2022]
Abstract
The chipmunk hibernation-related proteins (HPs) HP-20 and HP-27 are components of a 140-kDa complex that dramatically decreases in the blood during hibernation. The HP-20 and HP-27 genes are expressed specifically in the liver and are downregulated in hibernating chipmunks. Hibernation-associated physiological changes are assumed to be under genetic control. Therefore, to elucidate the molecular mechanisms of hibernation, here we examined the mechanisms behind the altered HP-20 and HP-27 gene expression in nonhibernating versus hibernating chipmunks. Chromatin immunoprecipitation (ChIP) analyses revealed that histone H3 on the HP-20 and HP-27 gene promoters was highly acetylated at lysine (K) 9 and K14 and highly trimethylated at K4 in the liver of nonhibernating chipmunks, while these active histone modifications were nearly absent in hibernating chipmunks. Furthermore, histone acetyltransferases and a histone methyltransferase were associated with the HP-20 and HP-27 gene promoters primarily in nonhibernating chipmunks. Consistent with a previous finding that HNF-1 and USF can activate HP-20 and HP-27 gene transcription by binding to the proximal promoter region, ChIP-quantitative PCR (qPCR) analyses revealed that significantly less HNF-1 and USF were bound to these gene promoters in hibernating than in nonhibernating chipmunks. These findings collectively indicated that the hibernation-associated HP-20 and HP-27 gene expression is epigenetically regulated at the transcriptional level by the binding of HNF-1 and USF to their proximal promoters, and that histone modification has a key role in hibernation-associated transcriptional regulation.
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Affiliation(s)
- Daisuke Tsukamoto
- Laboratory of Molecular Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Minamiku, Sagamihara, 252-0373, Japan.
| | - Michihiko Ito
- Laboratory of Molecular Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Minamiku, Sagamihara, 252-0373, Japan
| | - Nobuhiko Takamatsu
- Laboratory of Molecular Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Minamiku, Sagamihara, 252-0373, Japan.
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19
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Nora EP, Goloborodko A, Valton AL, Gibcus JH, Uebersohn A, Abdennur N, Dekker J, Mirny LA, Bruneau BG. Targeted Degradation of CTCF Decouples Local Insulation of Chromosome Domains from Genomic Compartmentalization. Cell 2017; 169:930-944.e22. [PMID: 28525758 PMCID: PMC5538188 DOI: 10.1016/j.cell.2017.05.004] [Citation(s) in RCA: 1011] [Impact Index Per Article: 144.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/14/2017] [Accepted: 05/02/2017] [Indexed: 01/17/2023]
Abstract
The molecular mechanisms underlying folding of mammalian chromosomes remain poorly understood. The transcription factor CTCF is a candidate regulator of chromosomal structure. Using the auxin-inducible degron system in mouse embryonic stem cells, we show that CTCF is absolutely and dose-dependently required for looping between CTCF target sites and insulation of topologically associating domains (TADs). Restoring CTCF reinstates proper architecture on altered chromosomes, indicating a powerful instructive function for CTCF in chromatin folding. CTCF remains essential for TAD organization in non-dividing cells. Surprisingly, active and inactive genome compartments remain properly segregated upon CTCF depletion, revealing that compartmentalization of mammalian chromosomes emerges independently of proper insulation of TADs. Furthermore, our data support that CTCF mediates transcriptional insulator function through enhancer blocking but not as a direct barrier to heterochromatin spreading. Beyond defining the functions of CTCF in chromosome folding, these results provide new fundamental insights into the rules governing mammalian genome organization.
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Affiliation(s)
- Elphège P Nora
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA; Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA.
| | - Anton Goloborodko
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anne-Laure Valton
- Howard Hughes Medical Institute, Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605-0103, USA
| | - Johan H Gibcus
- Howard Hughes Medical Institute, Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605-0103, USA
| | - Alec Uebersohn
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA; Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA
| | - Nezar Abdennur
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Job Dekker
- Howard Hughes Medical Institute, Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605-0103, USA
| | - Leonid A Mirny
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Benoit G Bruneau
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA; Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA; Department of Pediatrics, University of California, San Francisco, CA 94143, USA; Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA.
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20
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Hu T, Zhu X, Pi W, Yu M, Shi H, Tuan D. Hypermethylated LTR retrotransposon exhibits enhancer activity. Epigenetics 2017; 12:226-237. [PMID: 28165867 DOI: 10.1080/15592294.2017.1289300] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
LTR retrotransposons are repetitive DNA elements comprising ∼10% of the human genome. They are silenced by hypermethylation of cytosines in CpG dinucleotides and are considered parasitic DNA serving no useful function for the host genome. However, hypermethylated LTRs contain enhancer and promoter sequences and can promote tissue-specific transcription of cis-linked genes. To resolve the apparent paradox of hypermethylated LTRs possessing transcriptional activities, we studied the ERV-9 LTR retrotransposon located at the 5' border of the transcriptionally active β-globin gene locus in human erythroid progenitor and erythroleukemia K562 cells. We found that the ERV-9 LTR, containing 65 CpGs in 1.7 kb DNA, was hypermethylated (with > 90% methylated CpGs). Hypermethylated LTR possessed transcriptional enhancer activity, since in vivo deletion of the LTR by CRISPR-cas9 suppressed transcription of the globin genes by > 50%. ChIP-qPCR and ChIP-seq studies showed that the hypermethylated LTR enhancer spanning recurrent CCAATCG and GATA motifs associated respectively with key transcription factors (TFs) NF-Y and GATA-1 and -2 at reduced levels, compared with the unmethylated LTR in transfected LTR-reporter gene plasmids. Electrophoretic mobility shift assays with methylated LTR enhancer probe showed that the methylated probe bound both NF-Y and GATA-1 and -2 with lower affinities than the unmethylated enhancer probe. Thus, hypermethylation drastically reduced, but did not totally abolish, the binding affinities of the enhancer motifs to the key TFs to assemble the LTR-pol II transcription complex that activated transcription of cis-linked genes at reduced efficiency.
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Affiliation(s)
- Tianxiang Hu
- a Department of Biochemistry and Molecular Biology , Medical College of Georgia, Augusta University , Augusta , GA , USA
| | - Xingguo Zhu
- a Department of Biochemistry and Molecular Biology , Medical College of Georgia, Augusta University , Augusta , GA , USA
| | - Wenhu Pi
- a Department of Biochemistry and Molecular Biology , Medical College of Georgia, Augusta University , Augusta , GA , USA
| | - Miao Yu
- b Georgia Cancer Center , Medical College of Georgia, Augusta University , Augusta , GA , USA
| | - Huidong Shi
- b Georgia Cancer Center , Medical College of Georgia, Augusta University , Augusta , GA , USA
| | - Dorothy Tuan
- a Department of Biochemistry and Molecular Biology , Medical College of Georgia, Augusta University , Augusta , GA , USA
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21
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McKnight RA, Yost CC, Zinkhan EK, Fu Q, Callaway CW, Fung CM. Intrauterine growth restriction inhibits expression of eukaryotic elongation factor 2 kinase, a regulator of protein translation. Physiol Genomics 2016; 48:616-25. [PMID: 27317589 DOI: 10.1152/physiolgenomics.00045.2016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 06/14/2016] [Indexed: 11/22/2022] Open
Abstract
Nutrient deprivation suppresses protein synthesis by blocking peptide elongation. Transcriptional upregulation and activation of eukaryotic elongation factor 2 kinase (eEF2K) blocks peptide elongation by phosphorylating eukaryotic elongation factor 2. Previous studies examining placentas from intrauterine growth restricted (IUGR) newborn infants show decreased eEF2K expression and activity despite chronic nutrient deprivation. However, the effect of IUGR on hepatic eEF2K expression in the fetus is unknown. We, therefore, examined the transcriptional regulation of hepatic eEF2K gene expression in a Sprague-Dawley rat model of IUGR. We found decreased hepatic eEF2K mRNA and protein levels in IUGR offspring at birth compared with control, consistent with previous placental observations. Furthermore, the CpG island within the eEF2K promoter demonstrated increased methylation at a critical USF 1/2 transcription factor binding site. In vitro methylation of this binding site caused near complete loss of eEF2K promoter activity, designating this promoter as methylation sensitive. The eEF2K promotor in IUGR offspring also lost the protective histone covalent modifications associated with unmethylated CGIs. In addition, the +1 nucleosome was displaced 3' and RNA polymerase loading was reduced at the IUGR eEF2K promoter. Our findings provide evidence to explain why IUGR-induced chronic nutrient deprivation does not result in the upregulation of eEF2K gene transcription.
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Affiliation(s)
- Robert A McKnight
- Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Christian C Yost
- Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Erin K Zinkhan
- Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Qi Fu
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Christopher W Callaway
- Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Camille M Fung
- Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; and
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22
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Hyrsova L, Smutny T, Carazo A, Moravcik S, Mandikova J, Trejtnar F, Gerbal-Chaloin S, Pavek P. The pregnane X receptor down-regulates organic cation transporter 1 (SLC22A1) in human hepatocytes by competing for ("squelching") SRC-1 coactivator. Br J Pharmacol 2016; 173:1703-15. [PMID: 26920453 DOI: 10.1111/bph.13472] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE The organic cation transporter 1 (OCT1) transports cationic drugs into hepatocytes. The high hepatic expression of OCT1 is controlled by the HNF4α and USF transcription factors. Pregnane X receptor (PXR) mediates induction of the principal xenobiotic metabolizing enzymes and transporters in the liver. Here, we have assessed the down-regulation of OCT1 expression by PXR activation. EXPERIMENTAL APPROACH We used primary human hepatocytes and related cell lines to measure OCT1 expression and activity, by assaying MPP(+) accumulation. Western blotting, qRT-PCR, the OCT1 promoter gene reporter constructs and chromatin immunoprecipitation assays were also used. KEY RESULTS OCT1 mRNA in human hepatocytes was down-regulated along with reduced [(3) H]MPP(+) accumulation in differentiated HepaRG cells after treatment with rifampicin. Rifampicin and hyperforin as well as the constitutively active PXR mutant T248D suppressed activity of the 1.8 kb OCT1 promoter construct in gene reporter assays. Silencing of both PXR and HNF4α in HepaRG cells blocked the PXR ligand-mediated down-regulation of OCT1 expression. The mutation of HNF4α and USF1 (E-box) responsive elements reversed the PXR-mediated inhibition in gene reporter assays. Chromatin immunoprecipitation assays indicated that PXR activation sequestrates the SRC-1 coactivator from the HNF4α response element and E-box of the OCT1 promoter. Consistent with these findings, exogenous overexpression of the SRC-1, but not the PGC1α coactivator, relieved the PXR-mediated repression of OCT1 transactivation. CONCLUSIONS AND IMPLICATIONS PXR ligands reduced the HNF4α-mediated and USF-mediated transactivation of OCT1 gene expression by competing for SRC-1 and decreased delivery of a model OCT1 substrate into hepatocytes.
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Affiliation(s)
- Lucie Hyrsova
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Tomas Smutny
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Alejandro Carazo
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Stefan Moravcik
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Jana Mandikova
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Frantisek Trejtnar
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Sabine Gerbal-Chaloin
- INSERM, U1183, Institute for Regenerative Medicine and Biotherapy, Montpellier, France.,Université de Montpellier, Montpellier, France
| | - Petr Pavek
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
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Yuan Q, Bu Q, Li G, Zhang J, Cui T, Zhu R, Mu D. Association between single nucleotide polymorphisms of upstream transcription factor 1 (USF1) and susceptibility to papillary thyroid cancer. Clin Endocrinol (Oxf) 2016; 84:564-70. [PMID: 26052935 DOI: 10.1111/cen.12832] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 01/02/2015] [Accepted: 06/01/2015] [Indexed: 11/27/2022]
Abstract
BACKGROUND Thyroid cancer, predominantly by papillary thyroid cancer (PTC), is a malignant tumour of endocrine system with increasing incidence rate worldwide. Upstream transcription factor 1 (USF1) regulates a variety of biological processes by transactivation of functional genes. In this study, we investigated the association between USF1 polymorphisms and PTC risk. MATERIAL & METHODS A total of 334 patients with PTC, 186 patients with benign nodules (BN) and 668 healthy controls were enrolled in our study. Tag-SNPs were identified in Chinese Han in Beijing (CHB) from International HapMap Project Databases. Genomic DNAs were extracted by TaqMan Blood DNA kits. SNPs of USF1 were genotyped by TaqMan SNPs genotyping assay. Odds ratios (OR) and corresponding 95% confidence interval (CI) were used to assess the association between USF1 genetic variants and PTC risk. The statistical analyses were carried out with spss 13.0 software. RESULTS Five tag-SNPs were retrieved to capture all the genetic variants of USF1. Among the five tag-SNPs, genetic variants in rs2516838, rs3737787 and rs2516839 have significant association with PTC risk. The rs2516838 polymorphisms dominant model (CG+GG vs CC: OR = 0·71; 95% CI: 0·52-0·97; P = 0·033) and allelic model (C vs G: OR = 0·031; 95% CI: 0·56-0·97; P = 0·031) indicated it may act as a protective factor against PTC. On the contrary, the results of rs3737787 polymorphisms: dominant model (CT+TT vs CC: OR = 1·55; 95%CI: 1·09-2·02; P = 0·001) and allelic model (C vs T: OR = 1·35; 95%CI: 1·10-1·64; P = 0·003), as well as the results of rs2516839 polymorphisms: dominant model (GA+AA vs GG: OR = 1·77; 95%CI: 1·31-2·38; P < 0·001) and allelic model (G vs A: OR = 1·36; 95%CI: 1·13-1·63; P = 0·014), revealed that they may act as risk factors for PTC. CONCLUSION In this study, we found the SNPs of rs2516838 (mutant G alleles vs wild C alleles), rs3737787 (mutant T alleles vs wild C alleles) and rs2516839 (mutant A alleles vs wild G alleles) were significantly associated with PTC risk. Further large-scale studies with different ethnicities are still needed to validate our findings and explore the underlying mechanism of USF1 in PTC development.
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Affiliation(s)
- Qingzhong Yuan
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Qingao Bu
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Guoqiang Li
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Jun Zhang
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Tao Cui
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Rui Zhu
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Dongpo Mu
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
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Zeng Y, Li H, Zhang X, Shang J, Kang Y. Basal transcription of APOBEC3G is regulated by USF1 gene in hepatocyte. Biochem Biophys Res Commun 2016; 470:54-60. [PMID: 26772882 DOI: 10.1016/j.bbrc.2015.12.108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 12/23/2015] [Indexed: 11/13/2022]
Abstract
Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G, A3G) exert antiviral defense as an important factor of innate immunity. A variety of cytokines such as IFN-γ、IL2、IL15、IL7 could induce the transcription of A3G. However, the regulation of other nuclear factor on the transcription of A3G have not been reported at the present. To gain new insights into the transcriptional regulation of this restriction factor, we cloned and characterized the promoter region of A3G and investigate the modulation of USF1 gene on the transcription of A3G. We identified a 232 bp region that was sufficient to regulate the activity of full promoter. Transcriptional start sites (TSS) were identified by the luciferase reporter assays of plasmids containing full or shorter fragments of the A3G promoter. The results demonstrated that the core promoter of A3G is located within the region -159/-84 relative to the TSS. Transcriptional activity of A3G core promoter regulated by USF1 was dependent on an E-box (located at position -91/-86 relative to the major TSS) and was abolished after mutation of this DNA element. USF1 gene can take part in basal transcription regulation of the human A3G gene in hepatocyte, and the identified E-box represented a binding site for the USF1.
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Affiliation(s)
- Yanli Zeng
- Department of Infectious Diseases, Zhengzhou University People's Hospital (Henan Provincial People's Hospital), Zhengzhou, 450003, China
| | - Hui Li
- The Central Hospital of Wuhan, Tongji Medical College Huazhong University of Science Technology, Wuhan, 430000, China
| | - Xiaoju Zhang
- Department of Respiratory Medicine, Zhengzhou University People's Hospital (Henan Provincial People's Hospital), Zhengzhou, 450003, China
| | - Jia Shang
- Department of Infectious Diseases, Zhengzhou University People's Hospital (Henan Provincial People's Hospital), Zhengzhou, 450003, China
| | - Yi Kang
- Department of Infectious Diseases, Zhengzhou University People's Hospital (Henan Provincial People's Hospital), Zhengzhou, 450003, China.
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Cieślik M, Bekiranov S. Genome-wide predictors of NF-κB recruitment and transcriptional activity. BioData Min 2015; 8:37. [PMID: 26617673 PMCID: PMC4661973 DOI: 10.1186/s13040-015-0071-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 11/18/2015] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Inducible transcription factors (TFs) mediate transcriptional responses to environmental cues. In response to multiple inflammatory signals active NF-κB dimers enter the nucleus and trigger cell-type-, and stimulus-specific transcriptional programs. Although much is known about NF-κB inducing pathways and about locus-specific mechanisms of transcriptional control, it is poorly understood how the pre-existing chromatin landscape determines NF-κB target selection and activation. Specifically, it is not known which epigenetic marks and pre-bound TFs serve genome-wide as positive (negative) cues for active NF-κB. RESULTS We applied multivariate and combinatorial data mining techniques on a comprehensive dataset of DNA methylation, DNase I hypersensitivity, eight epigenetic marks, and 34 TFs to arrive at genome-wide patterns that predict NF-κB binding. Strikingly, we observed NF-κB recruitment to accessible and nucleosome-bound sites. Within nucleosomal DNA NF-κB binding was primed by H3K4me1 and H2A.Z, but also hyper-methylated DNA outside of promoters and CpG-islands. Many of these predictors showed combinatorial cooperativity and statistically significant interactions. Recruitment to pre-accessible sites was more frequent and influenced by chromatin-associated TFs. We observed that specific TF-combinations are greatly enriched for (or depleted of) NF-κB binding events. CONCLUSIONS We provide evidence of NF-κB binding within genomic regions that lack classical marks of activity. These pioneer binding events are relatively often associated with transcriptional regulation. Further, our predictive models indicate that specific combinations of epigenetic marks and transcription factors predetermine the NF-κB cistrome, supporting the feasibility of using statistical approaches to identify "histone codes".
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Affiliation(s)
- Marcin Cieślik
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia USA
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109 USA
| | - Stefan Bekiranov
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia USA
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Majumder K, Bassing CH, Oltz EM. Regulation of Tcrb Gene Assembly by Genetic, Epigenetic, and Topological Mechanisms. Adv Immunol 2015; 128:273-306. [PMID: 26477369 DOI: 10.1016/bs.ai.2015.07.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The adaptive immune system endows mammals with an ability to recognize nearly any foreign invader through antigen receptors that are expressed on the surface of all lymphocytes. This defense network is generated by V(D)J recombination, a set of sequentially controlled DNA cleavage and repair events that assemble antigen receptor genes from physically separated variable (V), joining (J), and sometimes diversity (D) gene segments. The recombination process itself must be stringently regulated to minimize oncogenic translocations involving chromosomes that harbor immunoglobulin and T cell receptor loci. Indeed, V(D)J recombination is controlled at several levels, including tissue-, developmental stage-, allele-, and gene segment-specificity. These levels of control are imposed by a collection of architectural and regulatory elements that are distributed throughout each antigen receptor locus. Together, the genetic elements regulate developmental changes in chromatin, transcription, and locus topology that promote or disfavor long-range recombination. This chapter focuses on the cross talk between these mechanisms at the T cell receptor beta (Tcrb) locus, and how they sculpt a diverse TCRβ repertoire while maintaining monospecificity of this antigen receptor on each mature T lymphocyte. We also discuss how insights obtained from studies of Tcrb are more generally relevant to our understanding of gene regulation strategies employed by mammals.
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Affiliation(s)
- Kinjal Majumder
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Craig H Bassing
- Division of Cancer Pathobiology, Department of Pathology and Laboratory Medicine, Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; Abramson Family Cancer Research Institute, Cell and Molecular Biology Graduate Program, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Eugene M Oltz
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA.
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González-Buendía E, Escamilla-Del-Arenal M, Pérez-Molina R, Tena JJ, Guerrero G, Suaste-Olmos F, Ayala-Ortega E, Gómez-Skarmeta JL, Recillas-Targa F. A novel chromatin insulator regulates the chicken folate receptor gene from the influence of nearby constitutive heterochromatin and the β-globin locus. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:955-65. [DOI: 10.1016/j.bbagrm.2015.05.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 05/22/2015] [Accepted: 05/25/2015] [Indexed: 11/17/2022]
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Maksimenko O, Gasanov NB, Georgiev P. Regulatory Elements in Vectors for Efficient Generation of Cell Lines Producing Target Proteins. Acta Naturae 2015; 7:15-26. [PMID: 26483956 PMCID: PMC4610161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
To date, there has been an increasing number of drugs produced in mammalian cell cultures. In order to enhance the expression level and stability of target recombinant proteins in cell cultures, various regulatory elements with poorly studied mechanisms of action are used. In this review, we summarize and discuss the potential mechanisms of action of such regulatory elements.
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Affiliation(s)
- O. Maksimenko
- Institute of Gene Biology, Russian Academy of Sciences, Vavilova str. 34/5, 119334, Moscow, Russia
| | - N. B. Gasanov
- Institute of Gene Biology, Russian Academy of Sciences, Vavilova str. 34/5, 119334, Moscow, Russia
| | - P. Georgiev
- Institute of Gene Biology, Russian Academy of Sciences, Vavilova str. 34/5, 119334, Moscow, Russia
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Guo Y, Fu X, Jin Y, Sun J, Liu Y, Huo B, Li X, Hu X. Histone demethylase LSD1-mediated repression of GATA-2 is critical for erythroid differentiation. DRUG DESIGN DEVELOPMENT AND THERAPY 2015; 9:3153-62. [PMID: 26124638 PMCID: PMC4482369 DOI: 10.2147/dddt.s81911] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Background The transcription factor GATA-2 is predominantly expressed in hematopoietic stem and progenitor cells and counteracts the erythroid-specific transcription factor GATA-1, to modulate the proliferation and differentiation of hematopoietic cells. During hematopoietic cell differentiation, GATA-2 exhibits dynamic expression patterns, which are regulated by multiple transcription factors. Methods Stable LSD1-knockdown cell lines were established by growing murine erythroleukemia (MEL) or mouse embryonic stem cells together with virus particles, in the presence of Polybrene® at 4 μg/mL, for 24–48 hours followed by puromycin selection (1 μg/mL) for 2 weeks. Real-time polymerase chain reaction (PCR)-based quantitative chromatin immunoprecipitation (ChIP) analysis was used to test whether the TAL1 transcription factor is bound to 1S promoter in the GATA-2 locus or whether LSD1 colocalizes with TAL1 at the 1S promoter. The sequential ChIP assay was utilized to confirm the role of LSD1 in the regulation of H3K4me2 at the GATA-2 locus during erythroid differentiation. Western blot analysis was employed to detect the protein expression. The alamarBlue® assay was used to examine the proliferation of the cells, and the absorbance was monitored at optical density (OD) 570 nm and OD 600 nm. Results In this study, we showed that LSD1 regulates the expression of GATA-2 during erythroid differentiation. Knockdown of LSD1 results in increased GATA-2 expression and inhibits the differentiation of MEL and embryonic stem cells. Furthermore, we demonstrated that LSD1 binds to the 1S promoter of the GATA-2 locus and suppresses GATA-2 expression, via histone demethylation. Conclusion Our data revealed that LSD1 mediates erythroid differentiation, via epigenetic modification of the GATA-2 locus.
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Affiliation(s)
- Yidi Guo
- School of Life Sciences, Jilin University, Changchun, People's Republic of China
| | - Xueqi Fu
- School of Life Sciences, Jilin University, Changchun, People's Republic of China ; Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, Jilin University, Changchun, People's Republic of China
| | - Yue Jin
- School of Life Sciences, Jilin University, Changchun, People's Republic of China
| | - Jing Sun
- School of Life Sciences, Jilin University, Changchun, People's Republic of China
| | - Ye Liu
- School of Life Sciences, Jilin University, Changchun, People's Republic of China
| | - Bo Huo
- School of Life Sciences, Jilin University, Changchun, People's Republic of China
| | - Xiang Li
- School of Life Sciences, Jilin University, Changchun, People's Republic of China
| | - Xin Hu
- School of Life Sciences, Jilin University, Changchun, People's Republic of China ; Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, Jilin University, Changchun, People's Republic of China ; National Engineering Laboratory of AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, People's Republic of China
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Cheng SL, Ramachandran B, Behrmann A, Shao JS, Mead M, Smith C, Krchma K, Bello Arredondo Y, Kovacs A, Kapoor K, Brill LM, Perera R, Williams BO, Towler DA. Vascular smooth muscle LRP6 limits arteriosclerotic calcification in diabetic LDLR-/- mice by restraining noncanonical Wnt signals. Circ Res 2015; 117:142-56. [PMID: 26034040 DOI: 10.1161/circresaha.117.306712] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/28/2015] [Indexed: 11/16/2022]
Abstract
RATIONALE Wnt signaling regulates key aspects of diabetic vascular disease. OBJECTIVE We generated SM22-Cre;LRP6(fl/fl);LDLR(-/-) mice to determine contributions of Wnt coreceptor low-density lipoprotein receptor-related protein 6 (LRP6) in the vascular smooth muscle lineage of male low-density lipoprotein receptor-null mice, a background susceptible to diet (high-fat diet)-induced diabetic arteriosclerosis. METHODS AND RESULTS As compared with LRP6(fl/fl);LDLR(-/-) controls, SM22-Cre;LRP6(fl/fl);LDLR(-/-) (LRP6-VKO) siblings exhibited increased aortic calcification on high-fat diet without changes in fasting glucose, lipids, or body composition. Pulse wave velocity (index of arterial stiffness) was also increased. Vascular calcification paralleled enhanced aortic osteochondrogenic programs and circulating osteopontin (OPN), a matricellular regulator of arteriosclerosis. Survey of ligands and Frizzled (Fzd) receptor profiles in LRP6-VKO revealed upregulation of canonical and noncanonical Wnts alongside Fzd10. Fzd10 stimulated noncanonical signaling and OPN promoter activity via an upstream stimulatory factor (USF)-activated cognate inhibited by LRP6. RNA interference revealed that USF1 but not USF2 supports OPN expression in LRP6-VKO vascular smooth muscle lineage, and immunoprecipitation confirmed increased USF1 association with OPN chromatin. ML141, an antagonist of cdc42/Rac1 noncanonical signaling, inhibited USF1 activation, osteochondrogenic programs, alkaline phosphatase, and vascular smooth muscle lineage calcification. Mass spectrometry identified LRP6 binding to protein arginine methyltransferase (PRMT)-1, and nuclear asymmetrical dimethylarginine modification was increased with LRP6-VKO. RNA interference demonstrated that PRMT1 inhibits OPN and TNAP, whereas PRMT4 supports expression. USF1 complexes containing the histone H3 asymmetrically dimethylated on Arg-17 signature of PRMT4 are increased with LRP6-VKO. Jmjd6, a demethylase downregulated with LRP6 deficiency, inhibits OPN and TNAP expression, USF1: histone H3 asymmetrically dimethylated on Arg-17 complex formation, and transactivation. CONCLUSIONS LRP6 restrains vascular smooth muscle lineage noncanonical signals that promote osteochondrogenic differentiation, mediated in part via USF1- and arginine methylation-dependent relays.
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Affiliation(s)
- Su-Li Cheng
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Bindu Ramachandran
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Abraham Behrmann
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Jian-Su Shao
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Megan Mead
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Carolyn Smith
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Karen Krchma
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Yoanna Bello Arredondo
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Attila Kovacs
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Kapil Kapoor
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Laurence M Brill
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Ranjan Perera
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Bart O Williams
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.)
| | - Dwight A Towler
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Cardiovascular Pathobiology, Orlando, FL (S.-L.C., B.R., A.B., M.M., C.S., Y.B.A., K.K., L.M.B., R.P., D.A.T.); MD Anderson Cancer Center, Cancer Biology, Houston, TX (J.-S.S.); Washington University, Department of Medicine, St. Louis, MO (K.K., A.K.); and Van Andel Research Institute, Department of Cancer and Cell Biology, Grand Rapids, MI (B.O.W.).
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Romero Z, Campo-Fernandez B, Wherley J, Kaufman ML, Urbinati F, Cooper AR, Hoban MD, Baldwin KM, Lumaquin D, Wang X, Senadheera S, Hollis RP, Kohn DB. The human ankyrin 1 promoter insulator sustains gene expression in a β-globin lentiviral vector in hematopoietic stem cells. Mol Ther Methods Clin Dev 2015; 2:15012. [PMID: 26029723 PMCID: PMC4445009 DOI: 10.1038/mtm.2015.12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 02/20/2015] [Indexed: 02/06/2023]
Abstract
Lentiviral vectors designed for the treatment of the hemoglobinopathies require the inclusion of regulatory and strong enhancer elements to achieve sufficient expression of the β-globin transgene. Despite the inclusion of these elements, the efficacy of these vectors may be limited by transgene silencing due to the genomic environment surrounding the integration site. Barrier insulators can be used to give more consistent expression and resist silencing even with lower vector copies. Here, the barrier activity of an insulator element from the human ankyrin-1 gene was analyzed in a lentiviral vector carrying an antisickling human β-globin gene. Inclusion of a single copy of the Ankyrin insulator did not affect viral titer, and improved the consistency of expression from the vector in murine erythroleukemia cells. The presence of the Ankyrin insulator element did not change transgene expression in human hematopoietic cells in short-term erythroid culture or in vivo in primary murine transplants. However, analysis in secondary recipients showed that the lentiviral vector with the Ankyrin element preserved transgene expression, whereas expression from the vector lacking the Ankyrin insulator decreased in secondary recipients. These studies demonstrate that the Ankyrin insulator may improve long-term β-globin expression in hematopoietic stem cells for gene therapy of hemoglobinopathies.
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Affiliation(s)
- Zulema Romero
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Beatriz Campo-Fernandez
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Jennifer Wherley
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Michael L Kaufman
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Fabrizia Urbinati
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Aaron R Cooper
- Molecular Biology Interdepartmental PhD Program, University of California, Los Angeles, California, USA
| | - Megan D Hoban
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Kismet M Baldwin
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Dianne Lumaquin
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Xiaoyan Wang
- Department of Internal Medicine and Health Services Research, University of California, Los Angeles, California, USA
| | - Shantha Senadheera
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Roger P Hollis
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Donald B Kohn
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
- Department of Pediatrics, UCLA Children’s Discovery and Innovation Institute David Geffen School of Medicine, University of California, Los Angeles, California, USA
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Carrió E, Díez-Villanueva A, Lois S, Mallona I, Cases I, Forn M, Peinado MA, Suelves M. Deconstruction of DNA methylation patterns during myogenesis reveals specific epigenetic events in the establishment of the skeletal muscle lineage. Stem Cells 2015; 33:2025-36. [PMID: 25801824 DOI: 10.1002/stem.1998] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/06/2015] [Indexed: 12/17/2022]
Abstract
The progressive restriction of differentiation potential from pluripotent embryonic stem cells (ESCs) to tissue-specific stem cells involves widespread epigenetic reprogramming, including modulation of DNA methylation patterns. Skeletal muscle stem cells are required for the growth, maintenance, and regeneration of skeletal muscle. To investigate the contribution of DNA methylation to the establishment of the myogenic program, we analyzed ESCs, skeletal muscle stem cells in proliferating (myoblasts) and differentiating conditions (myotubes), and mature myofibers. About 1.000 differentially methylated regions were identified during muscle-lineage determination and terminal differentiation, mainly located in gene bodies and intergenic regions. As a whole, myogenic stem cells showed a gain of DNA methylation, while muscle differentiation was accompanied by loss of DNA methylation in CpG-poor regions. Notably, the hypomethylated regions in myogenic stem cells were neighbored by enhancer-type chromatin, suggesting the involvement of DNA methylation in the regulation of cell-type specific enhancers. Interestingly, we demonstrated the hypomethylation of the muscle cell-identity Myf5 super-enhancer only in muscle cells. Furthermore, we observed that upstream stimulatory factor 1 binding to Myf5 super-enhancer occurs upon DNA demethylation in myogenic stem cells. Taken altogether, we characterized the unique DNA methylation signature of skeletal muscle stem cells and highlighted the importance of DNA methylation-mediated regulation of cell identity Myf5 super-enhancer during cellular differentiation.
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Affiliation(s)
- Elvira Carrió
- Institut de Medicina Predictiva i Personalitzada del Càncer (IMPPC).,Institut Germans Trias i Pujol (IGTP), Campus Can Ruti, 08916, Badalona, Spain
| | - Anna Díez-Villanueva
- Institut de Medicina Predictiva i Personalitzada del Càncer (IMPPC).,Institut Germans Trias i Pujol (IGTP), Campus Can Ruti, 08916, Badalona, Spain
| | - Sergi Lois
- Institut de Medicina Predictiva i Personalitzada del Càncer (IMPPC)
| | - Izaskun Mallona
- Institut de Medicina Predictiva i Personalitzada del Càncer (IMPPC).,Institut Germans Trias i Pujol (IGTP), Campus Can Ruti, 08916, Badalona, Spain
| | - Ildefonso Cases
- Institut de Medicina Predictiva i Personalitzada del Càncer (IMPPC)
| | - Marta Forn
- Institut de Medicina Predictiva i Personalitzada del Càncer (IMPPC)
| | - Miguel A Peinado
- Institut de Medicina Predictiva i Personalitzada del Càncer (IMPPC).,Institut Germans Trias i Pujol (IGTP), Campus Can Ruti, 08916, Badalona, Spain
| | - Mònica Suelves
- Institut de Medicina Predictiva i Personalitzada del Càncer (IMPPC).,Institut Germans Trias i Pujol (IGTP), Campus Can Ruti, 08916, Badalona, Spain
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33
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Tahara T, Arisawa T. Pathogenesis of CpG island methylator phenotype-positive colorectal cancers: role of genetic alteration and colonic flora. Epigenomics 2015; 6:249-51. [PMID: 25111477 DOI: 10.2217/epi.14.25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Tomomitsu Tahara
- Department of Gastroenterology, Fujita Health University School of Medicine, 1-98 Dengakugakubo Kutsukake-cho, Toyoake, Aichi, 470-1192, Toyoake, Japan
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34
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Wong KC, Li Y, Peng C, Zhang Z. SignalSpider: probabilistic pattern discovery on multiple normalized ChIP-Seq signal profiles. ACTA ACUST UNITED AC 2014; 31:17-24. [PMID: 25192742 DOI: 10.1093/bioinformatics/btu604] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
MOTIVATION Chromatin immunoprecipitation (ChIP) followed by high-throughput sequencing (ChIP-Seq) measures the genome-wide occupancy of transcription factors in vivo. Different combinations of DNA-binding protein occupancies may result in a gene being expressed in different tissues or at different developmental stages. To fully understand the functions of genes, it is essential to develop probabilistic models on multiple ChIP-Seq profiles to decipher the combinatorial regulatory mechanisms by multiple transcription factors. RESULTS In this work, we describe a probabilistic model (SignalSpider) to decipher the combinatorial binding events of multiple transcription factors. Comparing with similar existing methods, we found SignalSpider performs better in clustering promoter and enhancer regions. Notably, SignalSpider can learn higher-order combinatorial patterns from multiple ChIP-Seq profiles. We have applied SignalSpider on the normalized ChIP-Seq profiles from the ENCODE consortium and learned model instances. We observed different higher-order enrichment and depletion patterns across sets of proteins. Those clustering patterns are supported by Gene Ontology (GO) enrichment, evolutionary conservation and chromatin interaction enrichment, offering biological insights for further focused studies. We also proposed a specific enrichment map visualization method to reveal the genome-wide transcription factor combinatorial patterns from the models built, which extend our existing fine-scale knowledge on gene regulation to a genome-wide level. AVAILABILITY AND IMPLEMENTATION The matrix-algebra-optimized executables and source codes are available at the authors' websites: http://www.cs.toronto.edu/∼wkc/SignalSpider.
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Affiliation(s)
- Ka-Chun Wong
- Department of Computer Science and Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada, CEMSE Division, King Abdullah University of Science and Technology, Thuwal, Jeddah, K.S.A., Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada Department of Computer Science and Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada, CEMSE Division, King Abdullah University of Science and Technology, Thuwal, Jeddah, K.S.A., Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Yue Li
- Department of Computer Science and Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada, CEMSE Division, King Abdullah University of Science and Technology, Thuwal, Jeddah, K.S.A., Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada Department of Computer Science and Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada, CEMSE Division, King Abdullah University of Science and Technology, Thuwal, Jeddah, K.S.A., Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Chengbin Peng
- Department of Computer Science and Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada, CEMSE Division, King Abdullah University of Science and Technology, Thuwal, Jeddah, K.S.A., Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Zhaolei Zhang
- Department of Computer Science and Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada, CEMSE Division, King Abdullah University of Science and Technology, Thuwal, Jeddah, K.S.A., Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada Department of Computer Science and Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada, CEMSE Division, King Abdullah University of Science and Technology, Thuwal, Jeddah, K.S.A., Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada Department of Computer Science and Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada, CEMSE Division, King Abdullah University of Science and Technology, Thuwal, Jeddah, K.S.A., Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada Department of Computer Science and Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada, CEMSE Division, King Abdullah University of Science and Technology, Thuwal, Jeddah, K.S.A., Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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35
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Cohen AL, Jia S. Noncoding RNAs and the borders of heterochromatin. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:835-47. [PMID: 25044367 DOI: 10.1002/wrna.1249] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Revised: 04/30/2014] [Accepted: 05/21/2014] [Indexed: 11/08/2022]
Abstract
Eukaryotic genomes contain long stretches of repetitive DNA sequences, which are the preferred sites for the assembly of heterochromatin structures. The formation of heterochromatin results in highly condensed chromosomal domains that limit the accessibility of DNA to the transcription and recombination machinery to maintain genome stability. Heterochromatin has the tendency to spread, and the formation of boundaries that block heterochromatin spreading is required to maintain stable gene expression patterns. Recent work has suggested that noncoding RNAs (ncRNAs) are involved in regulating boundary formation in addition to their well-established roles in chromatin regulation. Here, we present a review of our current understanding of the involvement of ncRNA at the boundaries of heterochromatin, highlighting their mechanisms of action in different settings.
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Affiliation(s)
- Allison L Cohen
- Department of Biological Sciences, Columbia University, New York, NY, USA
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36
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p53 requires the stress sensor USF1 to direct appropriate cell fate decision. PLoS Genet 2014; 10:e1004309. [PMID: 24831529 PMCID: PMC4022457 DOI: 10.1371/journal.pgen.1004309] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 03/02/2014] [Indexed: 11/19/2022] Open
Abstract
Genomic instability is a major hallmark of cancer. To maintain genomic integrity, cells are equipped with dedicated sensors to monitor DNA repair or to force damaged cells into death programs. The tumor suppressor p53 is central in this process. Here, we report that the ubiquitous transcription factor Upstream Stimulatory factor 1 (USF1) coordinates p53 function in making proper cell fate decisions. USF1 stabilizes the p53 protein and promotes a transient cell cycle arrest, in the presence of DNA damage. Thus, cell proliferation is maintained inappropriately in Usf1 KO mice and in USF1-deficient melanoma cells challenged by genotoxic stress. We further demonstrate that the loss of USF1 compromises p53 stability by enhancing p53-MDM2 complex formation and MDM2-mediated degradation of p53. In USF1-deficient cells, the level of p53 can be restored by the re-expression of full-length USF1 protein similarly to what is observed using Nutlin-3, a specific inhibitor that prevents p53-MDM2 interaction. Consistent with a new function for USF1, a USF1 truncated protein lacking its DNA-binding and transactivation domains can also restore the induction and activity of p53. These findings establish that p53 function requires the ubiquitous stress sensor USF1 for appropriate cell fate decisions in response to DNA-damage. They underscore the new role of USF1 and give new clues of how p53 loss of function can occur in any cell type. Finally, these findings are of clinical relevance because they provide new therapeutic prospects in stabilizing and reactivating the p53 pathway. Cancer is a complex disease that is characterized by the sequential accumulation of genetic mutations. Exposure to environmental agents, such as solar ultraviolet, induces such alterations and thus contributes to the development of genomic instability. The tumor suppressor p53 has a central role in orchestrating cellular responses to genotoxic stress. In response to DNA-damage, p53 is stabilized and activated to direct cell fate decisions. Cells in which p53 stabilization is compromised become more vulnerable to mutagenic agents and hence the mutation rate increases, which promotes tumor development. Stabilization of p53 is thus a critical step towards cancer prevention. Using a genetic approach, we demonstrate that the ubiquitous transcription factor Upstream Stimulatory factor 1 (USF1) is required for immediate p53 stabilization and appropriate cell fate decisions following genotoxic stress. Furthermore, we show that this involves a novel function of USF1 that underscores its critical role as a stress sensor. The loss of USF1 expression should thus be considered as a potential initiator of tumorigenesis in the context of environmental insults.
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37
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Ong CT, Corces VG. CTCF: an architectural protein bridging genome topology and function. Nat Rev Genet 2014; 15:234-46. [PMID: 24614316 DOI: 10.1038/nrg3663] [Citation(s) in RCA: 703] [Impact Index Per Article: 70.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The eukaryotic genome is organized in the three-dimensional nuclear space in a specific manner that is both a cause and a consequence of its function. This organization is partly established by a special class of architectural proteins, of which CCCTC-binding factor (CTCF) is the best characterized. Although CTCF has been assigned various roles that are often contradictory, new results now help to draw a unifying model to explain the many functions of this protein. CTCF creates boundaries between topologically associating domains in chromosomes and, within these domains, facilitates interactions between transcription regulatory sequences. Thus, CTCF links the architecture of the genome to its function.
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Affiliation(s)
- Chin-Tong Ong
- Department of Biology, Emory University, 1510 Clifton Rd NE, Atlanta, Georgia 30322, USA
| | - Victor G Corces
- Department of Biology, Emory University, 1510 Clifton Rd NE, Atlanta, Georgia 30322, USA
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38
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Tahara T, Yamamoto E, Madireddi P, Suzuki H, Maruyama R, Chung W, Garriga J, Jelinek J, Yamano HO, Sugai T, Kondo Y, Toyota M, Issa JPJ, Estécio MRH. Colorectal carcinomas with CpG island methylator phenotype 1 frequently contain mutations in chromatin regulators. Gastroenterology 2014; 146:530-38.e5. [PMID: 24211491 PMCID: PMC3918446 DOI: 10.1053/j.gastro.2013.10.060] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 10/03/2013] [Accepted: 10/30/2013] [Indexed: 01/04/2023]
Abstract
BACKGROUND & AIMS Subgroups of colorectal carcinomas (CRCs) characterized by DNA methylation anomalies are termed CpG island methylator phenotype (CIMP)1, CIMP2, or CIMP-negative. The pathogenesis of CIMP1 colorectal carcinomas, and their effects on patients' prognoses and responses to treatment, differ from those of other CRCs. We sought to identify genetic somatic alterations associated with CIMP1 CRCs. METHODS We examined genomic DNA samples from 100 primary CRCs, 10 adenomas, and adjacent normal-appearing mucosae from patients undergoing surgery or colonoscopy at 3 tertiary medical centers. We performed exome sequencing of 16 colorectal tumors and their adjacent normal tissues. Extensive comparison with known somatic alterations in CRCs allowed segregation of CIMP1-exclusive alterations. The prevalence of mutations in selected genes was determined from an independent cohort. RESULTS We found that genes that regulate chromatin were mutated in CIMP1 CRCs; the highest rates of mutation were observed in CHD7 and CHD8, which encode members of the chromodomain helicase/adenosine triphosphate-dependent chromatin remodeling family. Somatic mutations in these 2 genes were detected in 5 of 9 CIMP1 CRCs. A prevalence screen showed that nonsilencing mutations in CHD7 and CHD8 occurred significantly more frequently in CIMP1 tumors (18 of 42 [43%]) than in CIMP2 (3 of 34 [9%]; P < .01) or CIMP-negative tumors (2 of 34 [6%]; P < .001). CIMP1 markers had increased binding by CHD7, compared with all genes. Genes altered in patients with CHARGE syndrome (congenital malformations involving the central nervous system, eye, ear, nose, and mediastinal organs) who had CHD7 mutations were also altered in CRCs with mutations in CHD7. CONCLUSIONS Aberrations in chromatin remodeling could contribute to the development of CIMP1 CRCs. A better understanding of the biological determinants of CRCs can be achieved when these tumors are categorized according to their epigenetic status.
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Affiliation(s)
- Tomomitsu Tahara
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Eiichiro Yamamoto
- First Department of Internal Medicine, Sapporo Medical University, Sapporo, Japan,Department of Molecular Biology, Sapporo Medical University, Sapporo, Japan
| | - Priyanka Madireddi
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Hiromu Suzuki
- Department of Molecular Biology, Sapporo Medical University, Sapporo, Japan
| | - Reo Maruyama
- Department of Molecular Biology, Sapporo Medical University, Sapporo, Japan
| | - Woonbok Chung
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Judith Garriga
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Jaroslav Jelinek
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Hiro-o Yamano
- Department of Gastroenterology, Akita Red Cross Hospital, Akita, Japan
| | - Tamotsu Sugai
- Department of Pathology, Iwate Medical University, Morioka, Japan
| | - Yutaka Kondo
- Division of Molecular Oncology, Aichi Cancer Center Research Institute, Nagoya, Japan
| | - Minoru Toyota
- Department of Molecular Biology, Sapporo Medical University, Sapporo, Japan
| | - Jean-Pierre J. Issa
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Marcos R. H. Estécio
- Department of Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, Texas,Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, Texas
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39
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Subtil-Rodríguez A, Vázquez-Chávez E, Ceballos-Chávez M, Rodríguez-Paredes M, Martín-Subero JI, Esteller M, Reyes JC. The chromatin remodeller CHD8 is required for E2F-dependent transcription activation of S-phase genes. Nucleic Acids Res 2013; 42:2185-96. [PMID: 24265227 PMCID: PMC3936757 DOI: 10.1093/nar/gkt1161] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The precise regulation of S-phase-specific genes is critical for cell proliferation. How the repressive chromatin configuration mediated by the retinoblastoma protein and repressor E2F factors changes at the G1/S transition to allow transcription activation is unclear. Here we show ChIP-on-chip studies that reveal that the chromatin remodeller CHD8 binds ∼ 2000 transcriptionally active promoters. The spectrum of CHD8 target genes was enriched in E2F-dependent genes. We found that CHD8 binds E2F-dependent promoters at the G1/S transition but not in quiescent cells. Consistently, CHD8 was required for G1/S-specific expression of these genes and for cell cycle re-entry on serum stimulation of quiescent cells. We also show that CHD8 interacts with E2F1 and, importantly, loading of E2F1 and E2F3, but not E2F4, onto S-specific promoters, requires CHD8. However, CHD8 recruiting is independent of these factors. Recruiting of MLL histone methyltransferase complexes to S-specific promoters was also severely impaired in the absence of CHD8. Furthermore, depletion of CHD8 abolished E2F1 overexpression-dependent S-phase stimulation of serum-starved cells, highlighting the essential role of CHD8 in E2F-dependent transcription activation.
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Affiliation(s)
- Alicia Subtil-Rodríguez
- Molecular Biology Department, Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), Av. Americo Vespucio 41092 Seville, Spain, Cancer Epigenetics and Biology Program, Bellvitge Biomedical Research Institute, L'Hospitalet, Barcelona, Spain and Department of Anatomic Pathology, Pharmacology and Microbiology, University of Barcelona, Spain
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The chicken HS4 insulator element does not protect the H19 ICR from differential DNA methylation in yeast artificial chromosome transgenic mouse. PLoS One 2013; 8:e73925. [PMID: 24023912 PMCID: PMC3762768 DOI: 10.1371/journal.pone.0073925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Accepted: 07/25/2013] [Indexed: 12/15/2022] Open
Abstract
Mono-allelic expression at the mouse IGF2/H19 locus is controlled by differential allelic DNA methylation of the imprinting control region (ICR). Because a randomly integrated H19 ICR fragment, when incorporated into the genome of transgenic mice (TgM), was allele-specifically methylated in somatic, but not in germ cells, it was suggested that allele-discriminating epigenetic signature, set within or somewhere outside of the Tg H19 ICR fragment in germ cells, was later translated into a differential DNA methylation pattern. To test if the chicken β-globin HS4 (cHS4) chromatin insulator might interfere with methylation imprinting establishment at the H19 ICR, we inserted the H19 ICR fragment, flanked by a set of floxed cHS4 core sequences, into a human β-globin locus YAC and generated TgM (insulated ICR' TgM). As controls, the cHS4 sequences were removed from one side (5'HS4-deleted ICR') or both sides (pseudo-WT ICR') of the insulated ICR' by in vivo cre-loxP recombination. The data show that while maternally inherited transgenic H19 ICR was not methylated in insulated ICR' TgM, it was significantly methylated upon paternal transmission, though the level was lower than in the pseudo-WT ICR' control. Because this reduced level of methylation was also observed in the 5'HS4-deleted ICR' TgM, we speculate that the phenotype is due to VEZF1-dependent demethylation activity, rather than the insulator function, borne in cHS4. Collectively, although we cannot rule out the possibility that cHS4 is incapable of blocking an allele-discriminating signal from outside of the transgene, the epigenetic signature appears to be marked intrinsically within the H19 ICR.
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41
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Lanni S, Goracci M, Borrelli L, Mancano G, Chiurazzi P, Moscato U, Ferrè F, Helmer-Citterich M, Tabolacci E, Neri G. Role of CTCF protein in regulating FMR1 locus transcription. PLoS Genet 2013; 9:e1003601. [PMID: 23874213 PMCID: PMC3715420 DOI: 10.1371/journal.pgen.1003601] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 05/13/2013] [Indexed: 01/07/2023] Open
Abstract
Fragile X syndrome (FXS), the leading cause of inherited intellectual disability, is caused by epigenetic silencing of the FMR1 gene, through expansion and methylation of a CGG triplet repeat (methylated full mutation). An antisense transcript (FMR1-AS1), starting from both promoter and intron 2 of the FMR1 gene, was demonstrated in transcriptionally active alleles, but not in silent FXS alleles. Moreover, a DNA methylation boundary, which is lost in FXS, was recently identified upstream of the FMR1 gene. Several nuclear proteins bind to this region, like the insulator protein CTCF. Here we demonstrate for the first time that rare unmethylated full mutation (UFM) alleles present the same boundary described in wild type (WT) alleles and that CTCF binds to this region, as well as to the FMR1 gene promoter, exon 1 and intron 2 binding sites. Contrariwise, DNA methylation prevents CTCF binding to FXS alleles. Drug-induced CpGs demethylation does not restore this binding. CTCF knock-down experiments clearly established that CTCF does not act as insulator at the active FMR1 locus, despite the presence of a CGG expansion. CTCF depletion induces heterochromatinic histone configuration of the FMR1 locus and results in reduction of FMR1 transcription, which however is not accompanied by spreading of DNA methylation towards the FMR1 promoter. CTCF depletion is also associated with FMR1-AS1 mRNA reduction. Antisense RNA, like sense transcript, is upregulated in UFM and absent in FXS cells and its splicing is correlated to that of the FMR1-mRNA. We conclude that CTCF has a complex role in regulating FMR1 expression, probably through the organization of chromatin loops between sense/antisense transcriptional regulatory regions, as suggested by bioinformatics analysis.
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Affiliation(s)
- Stella Lanni
- Istituto di Genetica Medica, Università Cattolica del S. Cuore, Rome, Italy
| | - Martina Goracci
- Istituto di Genetica Medica, Università Cattolica del S. Cuore, Rome, Italy
| | - Loredana Borrelli
- Istituto di Genetica Medica, Università Cattolica del S. Cuore, Rome, Italy
| | - Giorgia Mancano
- Istituto di Genetica Medica, Università Cattolica del S. Cuore, Rome, Italy
| | - Pietro Chiurazzi
- Istituto di Genetica Medica, Università Cattolica del S. Cuore, Rome, Italy
| | - Umberto Moscato
- Istituto di Igiene, Università Cattolica del S. Cuore, Rome, Italy
| | - Fabrizio Ferrè
- Dipartimento di Biologia, Università di Roma “Tor Vergata”, Rome, Italy
| | | | | | - Giovanni Neri
- Istituto di Genetica Medica, Università Cattolica del S. Cuore, Rome, Italy
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42
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Li G, Zhou L. Genome-wide identification of chromatin transitional regions reveals diverse mechanisms defining the boundary of facultative heterochromatin. PLoS One 2013; 8:e67156. [PMID: 23840609 PMCID: PMC3696093 DOI: 10.1371/journal.pone.0067156] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 05/14/2013] [Indexed: 11/18/2022] Open
Abstract
Due to the self-propagating nature of the heterochromatic modification H3K27me3, chromatin barrier activities are required to demarcate the boundary and prevent it from encroaching into euchromatic regions. Studies in Drosophila and vertebrate systems have revealed several important chromatin barrier elements and their respective binding factors. However, epigenomic data indicate that the binding of these factors are not exclusive to chromatin boundaries. To gain a comprehensive understanding of facultative heterochromatin boundaries, we developed a two-tiered method to identify the Chromatin Transitional Region (CTR), i.e. the nucleosomal region that shows the greatest transition rate of the H3K27me3 modification as revealed by ChIP-Seq. This approach was applied to identify CTRs in Drosophila S2 cells and human HeLa cells. Although many insulator proteins have been characterized in Drosophila, less than half of the CTRs in S2 cells are associated with known insulator proteins, indicating unknown mechanisms remain to be characterized. Our analysis also revealed that the peak binding of insulator proteins are usually 1–2 nucleosomes away from the CTR. Comparison of CTR-associated insulator protein binding sites vs. those in heterochromatic region revealed that boundary-associated binding sites are distinctively flanked by nucleosome destabilizing sequences, which correlates with significant decreased nucleosome density and increased binding intensities of co-factors. Interestingly, several subgroups of boundaries have enhanced H3.3 incorporation but reduced nucleosome turnover rate. Our genome-wide study reveals that diverse mechanisms are employed to define the boundaries of facultative heterochromatin. In both Drosophila and mammalian systems, only a small fraction of insulator protein binding sites co-localize with H3K27me3 boundaries. However, boundary-associated insulator binding sites are distinctively flanked by nucleosome destabilizing sequences, which correlates with significantly decreased nucleosome density and increased binding of co-factors.
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Affiliation(s)
- Guangyao Li
- Graduate Program in Genetics and Genomics, University of Florida Genetics Institute; Department of Molecular Genetics and Microbiology & University of Florida Shands Cancer Center, College of Medicine, University of Florida. Gainesville, Florida, United States of America
| | - Lei Zhou
- Graduate Program in Genetics and Genomics, University of Florida Genetics Institute; Department of Molecular Genetics and Microbiology & University of Florida Shands Cancer Center, College of Medicine, University of Florida. Gainesville, Florida, United States of America
- * E-mail:
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Deng C, Li Y, Liang S, Cui K, Salz T, Yang H, Tang Z, Gallagher PG, Qiu Y, Roeder R, Zhao K, Bungert J, Huang S. USF1 and hSET1A mediated epigenetic modifications regulate lineage differentiation and HoxB4 transcription. PLoS Genet 2013; 9:e1003524. [PMID: 23754954 PMCID: PMC3675019 DOI: 10.1371/journal.pgen.1003524] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 04/09/2013] [Indexed: 01/25/2023] Open
Abstract
The interplay between polycomb and trithorax complexes has been implicated in embryonic stem cell (ESC) self-renewal and differentiation. It has been shown recently that WRD5 and Dpy-30, specific components of the SET1/MLL protein complexes, play important roles during ESC self-renewal and differentiation of neural lineages. However, not much is known about how and where specific trithorax complexes are targeted to genes involved in self-renewal or lineage-specification. Here, we report that the recruitment of the hSET1A histone H3K4 methyltransferase (HMT) complex by transcription factor USF1 is required for mesoderm specification and lineage differentiation. In undifferentiated ESCs, USF1 maintains hematopoietic stem/progenitor cell (HS/PC) associated bivalent chromatin domains and differentiation potential. Furthermore, USF1 directed recruitment of the hSET1A complex to the HoxB4 promoter governs the transcriptional activation of HoxB4 gene and regulates the formation of early hematopoietic cell populations. Disruption of USF or hSET1A function by overexpression of a dominant-negative AUSF1 mutant or by RNA-interference-mediated knockdown, respectively, led to reduced expression of mesoderm markers and inhibition of lineage differentiation. We show that USF1 and hSET1A together regulate H3K4me3 modifications and transcription preinitiation complex assembly at the hematopoietic-associated HoxB4 gene during differentiation. Finally, ectopic expression of USF1 in ESCs promotes mesoderm differentiation and enforces the endothelial-to-hematopoietic transition by inducing hematopoietic-associated transcription factors, HoxB4 and TAL1. Taken together, our findings reveal that the guided-recruitment of the hSET1A histone methyltransferase complex and its H3K4 methyltransferase activity by transcription regulator USF1 safeguards hematopoietic transcription programs and enhances mesoderm/hematopoietic differentiation. Embryonic stem cells (ESCs) are capable of differentiating into any type of cell or tissue of the body. It is important to understand how developmental genes are controlled during differentiation of ESCs into specific cell types. The hSET1/MLL histone modifying protein complexes add methyl groups to lysine 4 on the N-terminal tails of the DNA associated protein histone H3 and activate gene expression. Although the hSET1/MLL enzymatic complexes play a role in activating genes involved in ESC growth and differentiation, how and where these activities are targeted to remains unclear. In this report, we demonstrate that DNA binding factor USF1 interacts with and brings the hSET1A enzymatic complex to its target gene, HoxB4, during blood cell specification and differentiation. Consistent with the function of HoxB4 in early blood cell formation, we found that the inactivation of USF1 or hSET1A activities leads to a block in the differentiation of blood cells and causes reductions in methylation levels of H3K4 and expression of HoxB4, without impairing the self-renewal capability of ESCs. Taken together, our findings reveal that the collaboration between the hSET1A enzymatic complex and DNA binding regulator USF1 activates developmental genes that control cellular differentiation programs during development.
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Affiliation(s)
- Changwang Deng
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Ying Li
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Shermi Liang
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Kairong Cui
- Systems Biology Center, NHLBI, NIH, Bethesda, Maryland, United States of America
| | - Tal Salz
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Hui Yang
- Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Zhanyun Tang
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York, United States of America
| | - Patrick G. Gallagher
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Yi Qiu
- Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Robert Roeder
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York, United States of America
| | - Keji Zhao
- Systems Biology Center, NHLBI, NIH, Bethesda, Maryland, United States of America
| | - Jörg Bungert
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, United States of America
- Genetics Institute, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Suming Huang
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, United States of America
- Genetics Institute, University of Florida College of Medicine, Gainesville, Florida, United States of America
- * E-mail:
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The dynamics of HCF-1 modulation of herpes simplex virus chromatin during initiation of infection. Viruses 2013; 5:1272-91. [PMID: 23698399 PMCID: PMC3712308 DOI: 10.3390/v5051272] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/14/2013] [Accepted: 05/14/2013] [Indexed: 12/30/2022] Open
Abstract
Successful infection of herpes simplex virus is dependent upon chromatin modulation by the cellular coactivator host cell factor-1 (HCF-1). This review focuses on the multiple chromatin modulation components associated with HCF-1 and the chromatin-related dynamics mediated by this coactivator that lead to the initiation of herpes simplex virus (HSV) immediate early gene expression.
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Yang CC, Buck MJ, Chen MH, Chen YF, Lan HC, Chen JJW, Cheng C, Liu CC. Discovering chromatin motifs using FAIRE sequencing and the human diploid genome. BMC Genomics 2013; 14:310. [PMID: 23656909 PMCID: PMC3655836 DOI: 10.1186/1471-2164-14-310] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 04/30/2013] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Specific chromatin structures are associated with active or inactive gene transcription. The gene regulatory elements are intrinsically dynamic and alternate between inactive and active states through the recruitment of DNA binding proteins, such as chromatin-remodeling proteins. RESULTS We developed a unique genome-wide method to discover DNA motifs associated with chromatin accessibility using formaldehyde-assisted isolation of regulatory elements with high-throughput sequencing (FAIRE-seq). We aligned the FAIRE-seq reads to the GM12878 diploid genome and subsequently identified differential chromatin-state regions (DCSRs) using heterozygous SNPs. The DCSR pairs represent the locations of imbalances of chromatin accessibility between alleles and are ideal to reveal chromatin motifs that may directly modulate chromatin accessibility. In this study, we used DNA 6-10mer sequences to interrogate all DCSRs, and subsequently discovered conserved chromatin motifs with significant changes in the occurrence frequency. To investigate their likely roles in biology, we studied the annotated protein associated with each of the top ten chromatin motifs genome-wide, in the intergenic regions and in genes, respectively. As a result, we found that most of these annotated motifs are associated with chromatin remodeling, reflecting their significance in biology. CONCLUSIONS Our method is the first one using fully phased diploid genome and FAIRE-seq to discover motifs associated with chromatin accessibility. Our results were collected to construct the first chromatin motif database (CMD), providing the potential DNA motifs recognized by chromatin-remodeling proteins and is freely available at http://syslab.nchu.edu.tw/chromatin.
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Affiliation(s)
- Chia-Chun Yang
- Institute of Molecular Biology, National Chung Hsing University, Taiwan, ROC
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Vorobyeva NE, Mazina MU, Golovnin AK, Kopytova DV, Gurskiy DY, Nabirochkina EN, Georgieva SG, Georgiev PG, Krasnov AN. Insulator protein Su(Hw) recruits SAGA and Brahma complexes and constitutes part of Origin Recognition Complex-binding sites in the Drosophila genome. Nucleic Acids Res 2013; 41:5717-30. [PMID: 23609538 PMCID: PMC3675495 DOI: 10.1093/nar/gkt297] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Despite increasing data on the properties of replication origins, molecular mechanisms underlying origin recognition complex (ORC) positioning in the genome are still poorly understood. The Su(Hw) protein accounts for the activity of best-studied Drosophila insulators. Here, we show that Su(Hw) recruits the histone acetyltransferase complex SAGA and chromatin remodeler Brahma to Su(Hw)-dependent insulators, which gives rise to regions with low nucleosome density and creates conditions for ORC binding. Depletion in Su(Hw) leads to a dramatic drop in the levels of SAGA, Brahma and ORC subunits and a significant increase in nucleosome density on Su(Hw)-dependent insulators, whereas artificial Su(Hw) recruitment itself is sufficient for subsequent SAGA, Brahma and ORC binding. In contrast to the majority of replication origins that associate with promoters of active genes, Su(Hw)-binding sites constitute a small proportion (6%) of ORC-binding sites that are localized preferentially in transcriptionally inactive chromatin regions termed BLACK and BLUE chromatin. We suggest that the key determinants of ORC positioning in the genome are DNA-binding proteins that constitute different DNA regulatory elements, including insulators, promoters and enhancers. Su(Hw) is the first example of such a protein.
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Affiliation(s)
- Nadezhda E Vorobyeva
- Department of Transcriptional Regulation and Chromatin Dynamics, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
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Fleming JD, Pavesi G, Benatti P, Imbriano C, Mantovani R, Struhl K. NF-Y coassociates with FOS at promoters, enhancers, repetitive elements, and inactive chromatin regions, and is stereo-positioned with growth-controlling transcription factors. Genome Res 2013; 23:1195-209. [PMID: 23595228 PMCID: PMC3730095 DOI: 10.1101/gr.148080.112] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
NF-Y, a trimeric transcription factor (TF) composed of two histone-like subunits (NF-YB and NF-YC) and a sequence-specific subunit (NF-YA), binds to the CCAAT motif, a common promoter element. Genome-wide mapping reveals 5000–15,000 NF-Y binding sites depending on the cell type, with the NF-YA and NF-YB subunits binding asymmetrically with respect to the CCAAT motif. Despite being characterized as a proximal promoter TF, only 25% of NF-Y sites map to promoters. A comparable number of NF-Y sites are located at enhancers, many of which are tissue specific, and nearly half of the NF-Y sites are in select subclasses of HERV LTR repeats. Unlike most TFs, NF-Y can access its target DNA motif in inactive (nonmodified) or polycomb-repressed chromatin domains. Unexpectedly, NF-Y extensively colocalizes with FOS in all genomic contexts, and this often occurs in the absence of JUN and the AP-1 motif. NF-Y also coassociates with a select cluster of growth-controlling and oncogenic TFs, consistent with the abundance of CCAAT motifs in the promoters of genes overexpressed in cancer. Interestingly, NF-Y and several growth-controlling TFs bind in a stereo-specific manner, suggesting a mechanism for cooperative action at promoters and enhancers. Our results indicate that NF-Y is not merely a commonly used proximal promoter TF, but rather performs a more diverse set of biological functions, many of which are likely to involve coassociation with FOS.
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Affiliation(s)
- Joseph D Fleming
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Razin SV, Ulianov SV, Ioudinkova ES, Gushchanskaya ES, Gavrilov AA, Iarovaia OV. Domains of α- and β-globin genes in the context of the structural-functional organization of the eukaryotic genome. BIOCHEMISTRY (MOSCOW) 2012; 77:1409-1423. [DOI: 10.1134/s0006297912130019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Ulyanov SV, Gavrilov AA. Chicken β-globin genes: A model system to study the transcriptional regulation at the level of genome domains. Mol Biol 2012. [DOI: 10.1134/s0026893312040127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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TFIIIC bound DNA elements in nuclear organization and insulation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1829:418-24. [PMID: 23000638 DOI: 10.1016/j.bbagrm.2012.09.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 09/14/2012] [Accepted: 09/15/2012] [Indexed: 11/23/2022]
Abstract
tRNA genes (tDNAs) have been known to have barrier insulator function in budding yeast, Saccharomyces cerevisiae, for over a decade. tDNAs also play a role in genome organization by clustering at sites in the nucleus and both of these functions are dependent on the transcription factor TFIIIC. More recently TFIIIC bound sites devoid of pol III, termed Extra-TFIIIC sites (ETC) have been identified in budding yeast and these sites also function as insulators and affect genome organization. Subsequent studies in Schizosaccharomyces pombe showed that TFIIIC bound sites were insulators and also functioned as Chromosome Organization Clamps (COC); tethering the sites to the nuclear periphery. Very recently studies have moved to mammalian systems where pol III genes and their associated factors have been investigated in both mouse and human cells. Short interspersed nuclear elements (SINEs) that bind TFIIIC, function as insulator elements and tDNAs can also function as both enhancer - blocking and barrier insulators in these organisms. It was also recently shown that tDNAs cluster with other tDNAs and with ETCs but not with pol II transcribed genes. Intriguingly, TFIIIC is often found near pol II transcription start sites and it remains unclear what the consequences of TFIIIC based genomic organization are and what influence pol III factors have on pol II transcribed genes and vice versa. In this review we provide a comprehensive overview of the known data on pol III factors in insulation and genome organization and identify the many open questions that require further investigation. This article is part of a Special Issue entitled: Transcription by Odd Pols.
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