201
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Webster DE, Barajas B, Bussat RT, Yan KJ, Neela PH, Flockhart RJ, Kovalski J, Zehnder A, Khavari PA. Enhancer-targeted genome editing selectively blocks innate resistance to oncokinase inhibition. Genome Res 2014; 24:751-60. [PMID: 24443471 PMCID: PMC4009605 DOI: 10.1101/gr.166231.113] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Thousands of putative enhancers are characterized in the human genome, yet few have been shown to have a functional role in cancer progression. Inhibiting oncokinases, such as EGFR, ALK, ERBB2, and BRAF, is a mainstay of current cancer therapy but is hindered by innate drug resistance mediated by up-regulation of the HGF receptor, MET. The mechanisms mediating such genomic responses to targeted therapy are unknown. Here, we identify lineage-specific enhancers at the MET locus for multiple common tumor types, including a melanoma lineage-specific enhancer 63 kb downstream from the MET TSS. This enhancer displays inducible chromatin looping with the MET promoter to up-regulate MET expression upon BRAF inhibition. Epigenomic analysis demonstrated that the melanocyte-specific transcription factor, MITF, mediates this enhancer function. Targeted genomic deletion (<7 bp) of the MITF motif within the MET enhancer suppressed inducible chromatin looping and innate drug resistance, while maintaining MITF-dependent, inhibitor-induced melanoma cell differentiation. Epigenomic analysis can thus guide functional disruption of regulatory DNA to decouple pro- and anti-oncogenic functions of a dominant transcription factor and block innate resistance to oncokinase therapy.
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Affiliation(s)
- Dan E Webster
- The Veterans Affairs Palo Alto Healthcare System, Palo Alto, California 94304, USA; The Program in Epithelial Biology, Stanford University School of Medicine, Stanford, California 94305, USA
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202
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Polak P, Lawrence MS, Haugen E, Stoletzki N, Stojanov P, Thurman RE, Garraway LA, Mirkin S, Getz G, Stamatoyannopoulos JA, Sunyaev SR. Reduced local mutation density in regulatory DNA of cancer genomes is linked to DNA repair. Nat Biotechnol 2013; 32:71-5. [PMID: 24336318 PMCID: PMC4116484 DOI: 10.1038/nbt.2778] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 11/22/2013] [Indexed: 12/28/2022]
Abstract
Carcinogenesis and neoplastic progression are mediated by the accumulation of somatic mutations. Here we report that the local density of somatic mutations in cancer genomes is highly reduced specifically in accessible regulatory DNA defined by DNase I hypersensitive sites. This reduction is independent of any known factors influencing somatic mutation density and is observed in diverse cancer types, suggesting a general mechanism. By analyzing individual cancer genomes1, we show that the reduced local mutation density within regulatory DNA is linked to intact global genome repair machinery, with nearly complete abrogation of the hypomutation phenomenon in individual cancers that possess mutations in multiple nucleotide excision repair components. Together, our results connect chromatin structure, gene regulation and cancer-associated somatic mutation.
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Affiliation(s)
- Paz Polak
- 1] Division of Genetics, Department of Medicine, Brigham & Women's Hospital, Boston, Massachusetts, USA. [2] Harvard Medical School, Boston, Massachusetts, USA. [3] The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA. [4]
| | - Michael S Lawrence
- 1] The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA. [2]
| | - Eric Haugen
- Departments of Genome Sciences and Medicine (Oncology), University of Washington, Seattle, Washington, USA
| | - Nina Stoletzki
- 1] Division of Genetics, Department of Medicine, Brigham & Women's Hospital, Boston, Massachusetts, USA. [2] Harvard Medical School, Boston, Massachusetts, USA. [3] The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Petar Stojanov
- The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Robert E Thurman
- Departments of Genome Sciences and Medicine (Oncology), University of Washington, Seattle, Washington, USA
| | - Levi A Garraway
- 1] Harvard Medical School, Boston, Massachusetts, USA. [2] The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA. [3] Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA. [4] Center for Cancer Genome Discovery, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Sergei Mirkin
- Department of Biology, Tufts University, Medford, Massachusetts, USA
| | - Gad Getz
- The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - John A Stamatoyannopoulos
- Departments of Genome Sciences and Medicine (Oncology), University of Washington, Seattle, Washington, USA
| | - Shamil R Sunyaev
- 1] Division of Genetics, Department of Medicine, Brigham & Women's Hospital, Boston, Massachusetts, USA. [2] Harvard Medical School, Boston, Massachusetts, USA. [3] The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
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203
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Singh AP, Archer TK. Analysis of the SWI/SNF chromatin-remodeling complex during early heart development and BAF250a repression cardiac gene transcription during P19 cell differentiation. Nucleic Acids Res 2013; 42:2958-75. [PMID: 24335282 PMCID: PMC3950667 DOI: 10.1093/nar/gkt1232] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The regulatory networks of differentiation programs and the molecular mechanisms of lineage-specific gene regulation in mammalian embryos remain only partially defined. We document differential expression and temporal switching of BRG1-associated factor (BAF) subunits, core pluripotency factors and cardiac-specific genes during post-implantation development and subsequent early organogenesis. Using affinity purification of BRG1 ATPase coupled to mass spectrometry, we characterized the cardiac-enriched remodeling complexes present in E8.5 mouse embryos. The relative abundance and combinatorial assembly of the BAF subunits provides functional specificity to Switch/Sucrose NonFermentable (SWI/SNF) complexes resulting in a unique gene expression profile in the developing heart. Remarkably, the specific depletion of the BAF250a subunit demonstrated differential effects on cardiac-specific gene expression and resulted in arrhythmic contracting cardiomyocytes in vitro. Indeed, the BAF250a physically interacts and functionally cooperates with Nucleosome Remodeling and Histone Deacetylase (NURD) complex subunits to repressively regulate chromatin structure of the cardiac genes by switching open and poised chromatin marks associated with active and repressed gene expression. Finally, BAF250a expression modulates BRG1 occupancy at the loci of cardiac genes regulatory regions in P19 cell differentiation. These findings reveal specialized and novel cardiac-enriched SWI/SNF chromatin-remodeling complexes, which are required for heart formation and critical for cardiac gene expression regulation at the early stages of heart development.
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Affiliation(s)
- Ajeet Pratap Singh
- Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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204
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Quigley DA, Fiorito E, Nord S, Van Loo P, Alnæs GG, Fleischer T, Tost J, Moen Vollan HK, Tramm T, Overgaard J, Bukholm IR, Hurtado A, Balmain A, Børresen-Dale AL, Kristensen V. The 5p12 breast cancer susceptibility locus affects MRPS30 expression in estrogen-receptor positive tumors. Mol Oncol 2013; 8:273-84. [PMID: 24388359 DOI: 10.1016/j.molonc.2013.11.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 11/19/2013] [Accepted: 11/21/2013] [Indexed: 11/17/2022] Open
Abstract
Genome-wide association studies have identified numerous loci linked to breast cancer susceptibility, but the mechanism by which variations at these loci influence susceptibility is usually unknown. Some variants are only associated with particular clinical subtypes of breast cancer. Understanding how and why these variants influence subtype-specific cancer risk contributes to our understanding of cancer etiology. We conducted a genome-wide expression Quantitative Trait Locus (eQTL) study in a discovery set of 287 breast tumors and 97 normal mammary tissue samples and a replication set of 235 breast tumors. We found that the risk-associated allele of rs7716600 in the 5p12 estrogen receptor-positive (ER-positive) susceptibility locus was associated with elevated expression of the nearby gene MRPS30 exclusively in ER-positive tumors. We replicated this finding in 235 independent tumors. Further, we showed the rs7716600 risk genotype was associated with decreased MRPS30 promoter methylation exclusively in ER-positive breast tumors. In vitro studies in MCF-7 cells carrying the protective genotype showed that estrogen stimulation decreased MRPS30 promoter chromatin availability and mRNA levels. In contrast, in 600MPE cells carrying the risk genotype, estrogen increased MRPS30 expression and did not affect promoter availability. Our data suggest the 5p12 risk allele affects MRPS30 expression in estrogen-responsive tumor cells after tumor initiation by a mechanism affecting chromatin availability. These studies emphasize that the genetic architecture of breast cancer is context-specific, and integrated analysis of gene expression and chromatin remodeling in normal and tumor tissues will be required to explain the mechanisms of risk alleles.
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Affiliation(s)
- David A Quigley
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway; K.G. Jebsen Center for Breast Cancer Research, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Helen Diller Family Comprehensive Cancer Center, University of California at San Francisco, San Francisco, USA.
| | - Elisa Fiorito
- Breast Cancer Research Group, Nordic EMBL Partnership, Centre for Molecular Medicine Norway, (NCMM), University of Oslo, Norway.
| | - Silje Nord
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway; K.G. Jebsen Center for Breast Cancer Research, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Peter Van Loo
- Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton UK; Department of Human Genetics, VIB and KU Leuven, Leuven, Belgium.
| | - Grethe Grenaker Alnæs
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway; K.G. Jebsen Center for Breast Cancer Research, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Thomas Fleischer
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway; K.G. Jebsen Center for Breast Cancer Research, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Jorg Tost
- Laboratory for Functional Genomics, Fondation Jean Dausset, Centre Etude Polymorphism Humain, (CEPH), Paris, France; Laboratory of Epigenetics, Centre National de Génotypage, Commissariat à l'énergie Atomique et, aux énergies Alternatives (CEA)-Institut de Génomique, Evry, France.
| | - Hans Kristian Moen Vollan
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway; K.G. Jebsen Center for Breast Cancer Research, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Trine Tramm
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark.
| | - Jens Overgaard
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark.
| | - Ida R Bukholm
- Department of Breast-Endocrine Surgery, Akershus University Hospital, Oslo, Norway; Department of Oncology, Division of Cancer Medicine, Surgery and Transplantation, Oslo University Hospital, Oslo, Norway.
| | - Antoni Hurtado
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway; K.G. Jebsen Center for Breast Cancer Research, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Breast Cancer Research Group, Nordic EMBL Partnership, Centre for Molecular Medicine Norway, (NCMM), University of Oslo, Norway.
| | - Allan Balmain
- Helen Diller Family Comprehensive Cancer Center, University of California at San Francisco, San Francisco, USA.
| | - Anne-Lise Børresen-Dale
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway; K.G. Jebsen Center for Breast Cancer Research, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Vessela Kristensen
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway; K.G. Jebsen Center for Breast Cancer Research, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Clinical Molecular Biology (EpiGen), Medical Division, Akershus University Hospital, Lørenskog, Norway.
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205
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Insights into chromatin structure and dynamics in plants. BIOLOGY 2013; 2:1378-410. [PMID: 24833230 PMCID: PMC4009787 DOI: 10.3390/biology2041378] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 11/15/2013] [Accepted: 11/18/2013] [Indexed: 11/17/2022]
Abstract
The packaging of chromatin into the nucleus of a eukaryotic cell requires an extraordinary degree of compaction and physical organization. In recent years, it has been shown that this organization is dynamically orchestrated to regulate responses to exogenous stimuli as well as to guide complex cell-type-specific developmental programs. Gene expression is regulated by the compartmentalization of functional domains within the nucleus, by distinct nucleosome compositions accomplished via differential modifications on the histone tails and through the replacement of core histones by histone variants. In this review, we focus on these aspects of chromatin organization and discuss novel approaches such as live cell imaging and photobleaching as important tools likely to give significant insights into our understanding of the very dynamic nature of chromatin and chromatin regulatory processes. We highlight the contribution plant studies have made in this area showing the potential advantages of plants as models in understanding this fundamental aspect of biology.
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206
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Zhong S, He X, Bar-Joseph Z. Predicting tissue specific transcription factor binding sites. BMC Genomics 2013; 14:796. [PMID: 24238150 PMCID: PMC3898213 DOI: 10.1186/1471-2164-14-796] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 11/06/2013] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Studies of gene regulation often utilize genome-wide predictions of transcription factor (TF) binding sites. Most existing prediction methods are based on sequence information alone, ignoring biological contexts such as developmental stages and tissue types. Experimental methods to study in vivo binding, including ChIP-chip and ChIP-seq, can only study one transcription factor in a single cell type and under a specific condition in each experiment, and therefore cannot scale to determine the full set of regulatory interactions in mammalian transcriptional regulatory networks. RESULTS We developed a new computational approach, PIPES, for predicting tissue-specific TF binding. PIPES integrates in vitro protein binding microarrays (PBMs), sequence conservation and tissue-specific epigenetic (DNase I hypersensitivity) information. We demonstrate that PIPES improves over existing methods on distinguishing between in vivo bound and unbound sequences using ChIP-seq data for 11 mouse TFs. In addition, our predictions are in good agreement with current knowledge of tissue-specific TF regulation. CONCLUSIONS We provide a systematic map of computationally predicted tissue-specific binding targets for 284 mouse TFs across 55 tissue/cell types. Such comprehensive resource is useful for researchers studying gene regulation.
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Affiliation(s)
| | | | - Ziv Bar-Joseph
- Lane Center for Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
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207
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Stergachis AB, Neph S, Reynolds A, Humbert R, Miller B, Paige SL, Vernot B, Cheng JB, Thurman RE, Sandstrom R, Haugen E, Heimfeld S, Murry CE, Akey JM, Stamatoyannopoulos JA. Developmental fate and cellular maturity encoded in human regulatory DNA landscapes. Cell 2013; 154:888-903. [PMID: 23953118 DOI: 10.1016/j.cell.2013.07.020] [Citation(s) in RCA: 255] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 04/16/2013] [Accepted: 07/12/2013] [Indexed: 10/26/2022]
Abstract
Cellular-state information between generations of developing cells may be propagated via regulatory regions. We report consistent patterns of gain and loss of DNase I-hypersensitive sites (DHSs) as cells progress from embryonic stem cells (ESCs) to terminal fates. DHS patterns alone convey rich information about cell fate and lineage relationships distinct from information conveyed by gene expression. Developing cells share a proportion of their DHS landscapes with ESCs; that proportion decreases continuously in each cell type as differentiation progresses, providing a quantitative benchmark of developmental maturity. Developmentally stable DHSs densely encode binding sites for transcription factors involved in autoregulatory feedback circuits. In contrast to normal cells, cancer cells extensively reactivate silenced ESC DHSs and those from developmental programs external to the cell lineage from which the malignancy derives. Our results point to changes in regulatory DNA landscapes as quantitative indicators of cell-fate transitions, lineage relationships, and dysfunction.
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Affiliation(s)
- Andrew B Stergachis
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - Shane Neph
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - Alex Reynolds
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - Richard Humbert
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - Brady Miller
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA.,Department of Medicine, Division of Hematology University of Washington, Seattle, WA 98195, USA
| | - Sharon L Paige
- Department of Pathology, University of Washington, Seattle, WA 98109, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA
| | - Benjamin Vernot
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - Jeffrey B Cheng
- Department of Dermatology, University of California, San Francisco, CA 94143, USA
| | - Robert E Thurman
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - Richard Sandstrom
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - Eric Haugen
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - Shelly Heimfeld
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Charles E Murry
- Department of Pathology, University of Washington, Seattle, WA 98109, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA.,Department of Bioengineering, University of Washington, Seattle, WA 98109, USA.,Department of Medicine, Division of Cardiology University of Washington, Seattle, WA 98195, USA
| | - Joshua M Akey
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - John A Stamatoyannopoulos
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA.,Department of Medicine, Division of Oncology University of Washington, Seattle, WA 98195, USA
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208
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Benner C, Konovalov S, Mackintosh C, Hutt KR, Stunnenberg R, Garcia-Bassets I. Decoding a signature-based model of transcription cofactor recruitment dictated by cardinal cis-regulatory elements in proximal promoter regions. PLoS Genet 2013; 9:e1003906. [PMID: 24244184 PMCID: PMC3820735 DOI: 10.1371/journal.pgen.1003906] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 09/10/2013] [Indexed: 11/19/2022] Open
Abstract
Genome-wide maps of DNase I hypersensitive sites (DHSs) reveal that most human promoters contain perpetually active cis-regulatory elements between −150 bp and +50 bp (−150/+50 bp) relative to the transcription start site (TSS). Transcription factors (TFs) recruit cofactors (chromatin remodelers, histone/protein-modifying enzymes, and scaffold proteins) to these elements in order to organize the local chromatin structure and coordinate the balance of post-translational modifications nearby, contributing to the overall regulation of transcription. However, the rules of TF-mediated cofactor recruitment to the −150/+50 bp promoter regions remain poorly understood. Here, we provide evidence for a general model in which a series of cis-regulatory elements (here termed ‘cardinal’ motifs) prefer acting individually, rather than in fixed combinations, within the −150/+50 bp regions to recruit TFs that dictate cofactor signatures distinctive of specific promoter subsets. Subsequently, human promoters can be subclassified based on the presence of cardinal elements and their associated cofactor signatures. In this study, furthermore, we have focused on promoters containing the nuclear respiratory factor 1 (NRF1) motif as the cardinal cis-regulatory element and have identified the pervasive association of NRF1 with the cofactor lysine-specific demethylase 1 (LSD1/KDM1A). This signature might be distinctive of promoters regulating nuclear-encoded mitochondrial and other particular genes in at least some cells. Together, we propose that decoding a signature-based, expanded model of control at proximal promoter regions should lead to a better understanding of coordinated regulation of gene transcription. Human cells exploit different mechanisms to coordinate the expression of both protein-coding and non-coding RNAs. Elucidating these mechanisms is essential to understanding normal physiology and disease. In our attempt to identify new regulatory layers acting particularly at proximal promoters, we have computationally analyzed the genomic sequences located from −150 bp to +50 bp relative to the transcriptional start site (TSS), which are often at the center of ‘open’ chromatin regions in human promoters. We have confirmed the presence of a series of cis-regulatory elements (here referred to as ‘cardinal’ motifs) that show a strong preference for these short regions. Interestingly, these elements tend to act independently rather than in fixed combinations. Therefore, we propose that they confer unique regulatory features to the human promoter subsets that contain each of these particular elements. In agreement with this model, we have identified a large repertoire of preferential partnerships between transcription factors recognizing cardinal motifs and their associated proteins (cofactors), thus decoding a signature-based model that distinguishes distinctive regulatory types of promoters based on cardinal motifs. These signatures may underlie a new layer of transcriptional regulation to orchestrate coordinated gene expression in human promoters.
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Affiliation(s)
- Christopher Benner
- The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Sergiy Konovalov
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Carlos Mackintosh
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Kasey R. Hutt
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Rieka Stunnenberg
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Ivan Garcia-Bassets
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
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209
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Vierstra J, Wang H, John S, Sandstrom R, Stamatoyannopoulos JA. Coupling transcription factor occupancy to nucleosome architecture with DNase-FLASH. Nat Methods 2013; 11:66-72. [PMID: 24185839 DOI: 10.1038/nmeth.2713] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 10/04/2013] [Indexed: 12/16/2022]
Abstract
It is currently not possible to resolve the genome-wide relationship of transcription factors (TFs) and nucleosomes at the level of individual chromatin templates despite rapidly increasing data on TF and nucleosome occupancy in the human genome. Here we describe DNase I-released fragment-length analysis of hypersensitivity (DNase-FLASH), an approach that directly couples mapping of TF occupancy, via quantification of DNA microfragments released from individual TF recognition sites in regulatory DNA, to the surrounding nucleosome architecture, via analysis of larger DNA fragments, in a single assay. DNase-FLASH enables coupling of individual TF footprints to nucleosome occupancy, identifying TFs that precisely demarcate the regulatory DNA-nucleosome interface.
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Affiliation(s)
- Jeff Vierstra
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Hao Wang
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Sam John
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Richard Sandstrom
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - John A Stamatoyannopoulos
- 1] Department of Genome Sciences, University of Washington, Seattle, Washington, USA. [2] Department of Medicine, Division of Oncology, University of Washington, Seattle, Washington, USA
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210
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Ferg M, Armant O, Yang L, Dickmeis T, Rastegar S, Strähle U. Gene transcription in the zebrafish embryo: regulators and networks. Brief Funct Genomics 2013; 13:131-43. [PMID: 24152666 DOI: 10.1093/bfgp/elt044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The precise spatial and temporal control of gene expression is a key process in the development, maintenance and regeneration of the vertebrate body. A substantial proportion of vertebrate genomes encode genes that control the transcription of the genetic information into mRNA. The zebrafish is particularly well suited to investigate gene regulatory networks underlying the control of gene expression during development due to the external development of its transparent embryos and the increasingly sophisticated tools for genetic manipulation available for this model system. We review here recent data on the analysis of cis-regulatory modules, transcriptional regulators and their integration into gene regulatory networks in the zebrafish, using the developing spinal cord as example.
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Affiliation(s)
- Marco Ferg
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Postfach 3640, 76021 Karlsruhe, Germany.
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211
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A quantitative analysis of the impact on chromatin accessibility by histone modifications and binding of transcription factors in DNase I hypersensitive sites. BIOMED RESEARCH INTERNATIONAL 2013; 2013:914971. [PMID: 24236298 PMCID: PMC3819824 DOI: 10.1155/2013/914971] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/03/2013] [Indexed: 11/17/2022]
Abstract
It is known that chromatin features such as histone modifications and the binding of transcription factors exert a significant impact on the "openness" of chromatin. In this study, we present a quantitative analysis of the genome-wide relationship between chromatin features and chromatin accessibility in DNase I hypersensitive sites. We found that these features show distinct preference to localize in open chromatin. In order to elucidate the exact impact, we derived quantitative models to directly predict the "openness" of chromatin using histone modification features and transcription factor binding features, respectively. We show that these two types of features are highly predictive for chromatin accessibility in a statistical viewpoint. Moreover, our results indicate that these features are highly redundant and only a small number of features are needed to achieve a very high predictive power. Our study provides new insights into the true biological phenomena and the combinatorial effects of chromatin features to differential DNase I hypersensitivity.
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212
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Lu Y, Zhou Y, Tian W. Combining Hi-C data with phylogenetic correlation to predict the target genes of distal regulatory elements in human genome. Nucleic Acids Res 2013; 41:10391-402. [PMID: 24003029 PMCID: PMC3905853 DOI: 10.1093/nar/gkt785] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Defining the target genes of distal regulatory elements (DREs), such as enhancer, repressors and insulators, is a challenging task. The recently developed Hi-C technology is designed to capture chromosome conformation structure by high-throughput sequencing, and can be potentially used to determine the target genes of DREs. However, Hi-C data are noisy, making it difficult to directly use Hi-C data to identify DRE-target gene relationships. In this study, we show that DREs-gene pairs that are confirmed by Hi-C data are strongly phylogenetic correlated, and have thus developed a method that combines Hi-C read counts with phylogenetic correlation to predict long-range DRE-target gene relationships. Analysis of predicted DRE-target gene pairs shows that genes regulated by large number of DREs tend to have essential functions, and genes regulated by the same DREs tend to be functionally related and co-expressed. In addition, we show with a couple of examples that the predicted target genes of DREs can help explain the causal roles of disease-associated single-nucleotide polymorphisms located in the DREs. As such, these predictions will be of importance not only for our understanding of the function of DREs but also for elucidating the causal roles of disease-associated noncoding single-nucleotide polymorphisms.
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Affiliation(s)
- Yulan Lu
- State Key Laboratory of Genetic Engineering, Department of Biostatistics and Computational Biology, School of Life Science, Fudan University, Shanghai 200433, China
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213
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Xiong Q, Zhang Z, Chang KH, Qu H, Wang H, Qi H, Li Y, Ruan X, Yang Y, Yang Y, Li Y, Sandstrom R, Sabo PJ, Li Q, Stamatoyannopoulos G, Stamatoyannopoulos JA, Fang X. Comprehensive characterization of erythroid-specific enhancers in the genomic regions of human Krüppel-like factors. BMC Genomics 2013; 14:587. [PMID: 23985037 PMCID: PMC3846580 DOI: 10.1186/1471-2164-14-587] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 08/23/2013] [Indexed: 11/10/2022] Open
Abstract
Background Mapping of DNase I hypersensitive sites (DHSs) is a powerful tool to experimentally identify cis-regulatory elements (CREs). Among CREs, enhancers are abundant and predominantly act in driving cell-specific gene expression. Krüppel-like factors (KLFs) are a family of eukaryotic transcription factors. Several KLFs have been demonstrated to play important roles in hematopoiesis. However, transcriptional regulation of KLFs via CREs, particularly enhancers, in erythroid cells has been poorly understood. Results In this study, 23 erythroid-specific or putative erythroid-specific DHSs were identified by DNase-seq in the genomic regions of 17 human KLFs, and their enhancer activities were evaluated using dual-luciferase reporter (DLR) assay. Of the 23 erythroid-specific DHSs, the enhancer activities of 15 DHSs were comparable to that of the classical enhancer HS2 in driving minimal promoter (minP). Fifteen DHSs, some overlapping those that increased minP activities, acted as enhancers when driving the corresponding KLF promoters (KLF-Ps) in erythroid cells; of these, 10 DHSs were finally characterized as erythroid-specific KLF enhancers. These 10 erythroid-specific KLF enhancers were further confirmed using chromatin immunoprecipitation coupled to sequencing (ChIP-seq) data-based bioinformatic and biochemical analyses. Conclusion Our present findings provide a feasible strategy to extensively identify gene- and cell-specific enhancers from DHSs obtained by high-throughput sequencing, which will help reveal the transcriptional regulation and biological functions of genes in some specific cells.
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Affiliation(s)
- Qian Xiong
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, P,R, China.
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214
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Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic gammaherpesvirus which establishes latent infection in endothelial and B cells, as well as in primary effusion lymphoma (PEL). During latency, the viral genome exists as a circular DNA minichromosome (episome) and is packaged into chromatin analogous to human chromosomes. Only a small subset of promoters, those which drive latent RNAs, are active in latent episomes. In general, nucleosome depletion ("open chromatin") is a hallmark of eukaryotic regulatory elements such as promoters and transcriptional enhancers or insulators. We applied formaldehyde-assisted isolation of regulatory elements (FAIRE) followed by next-generation sequencing to identify regulatory elements in the KSHV genome and integrated these data with previously identified locations of histone modifications, RNA polymerase II occupancy, and CTCF binding sites. We found that (i) regions of open chromatin were not restricted to the transcriptionally defined latent loci; (ii) open chromatin was adjacent to regions harboring activating histone modifications, even at transcriptionally inactive loci; and (iii) CTCF binding sites fell within regions of open chromatin with few exceptions, including the constitutive LANA promoter and the vIL6 promoter. FAIRE-identified nucleosome depletion was similar among B and endothelial cell lineages, suggesting a common viral genome architecture in all forms of latency.
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215
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Abstract
Significant progress in molecular genetics has advanced our understanding of the genetic basis of migraine. The fundamentals of molecular genetics, and the recent advances in the field, are important for clinicians to understand, as they provide a foundation for critical appraisal of the literature, unprecedented insights into the pathogenesis of the disorder, and reveal promising treatment targets for future drug development. This paper provides a primer of molecular genetics and will be followed by a companion paper on the genetic advances in migraine, the methodology of genome wide association studies, and the potential clinical implications.
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216
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Hosseini M, Goodstadt L, Hughes JR, Kowalczyk MS, de Gobbi M, Otto GW, Copley RR, Mott R, Higgs DR, Flint J. Causes and consequences of chromatin variation between inbred mice. PLoS Genet 2013; 9:e1003570. [PMID: 23785304 PMCID: PMC3681629 DOI: 10.1371/journal.pgen.1003570] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 05/02/2013] [Indexed: 12/28/2022] Open
Abstract
Variation at regulatory elements, identified through hypersensitivity to digestion by DNase I, is believed to contribute to variation in complex traits, but the extent and consequences of this variation are poorly characterized. Analysis of terminally differentiated erythroblasts in eight inbred strains of mice identified reproducible variation at approximately 6% of DNase I hypersensitive sites (DHS). Only 30% of such variable DHS contain a sequence variant predictive of site variation. Nevertheless, sequence variants within variable DHS are more likely to be associated with complex traits than those in non-variant DHS, and variants associated with complex traits preferentially occur in variable DHS. Changes at a small proportion (less than 10%) of variable DHS are associated with changes in nearby transcriptional activity. Our results show that whilst DNA sequence variation is not the major determinant of variation in open chromatin, where such variants exist they are likely to be causal for complex traits. Regulatory sites of the genome affect gene expression and complex traits, including disease susceptibility. Variable regulatory sites are potentially interesting because they are a likely cause of phenotypic variation, providing a bridge between sequence and transcriptional variation. In this paper we identify regions of the genome where DNA is not wrapped up in chromatin (hence potentially regulatory) in eight inbred strains of mice. We compare sites that vary among strains and compare them to non-variable sites. We show that more than half of variable sites cannot be attributed to local sequence variation. Functional consequences (in terms of readily detectable changes in gene expression) are associated with less than 10% of variable DNase I hypersensitive sites. We show that variable sites are enriched for sequence variants contributing to complex traits in mice.
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Affiliation(s)
- Mona Hosseini
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Leo Goodstadt
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Jim R. Hughes
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Monika S. Kowalczyk
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Marco de Gobbi
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Georg W. Otto
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | | | - Richard Mott
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Douglas R. Higgs
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Jonathan Flint
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
- * E-mail:
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217
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Simon JM, Giresi PG, Davis IJ, Lieb JD. A detailed protocol for formaldehyde-assisted isolation of regulatory elements (FAIRE). ACTA ACUST UNITED AC 2013; Chapter 21:Unit21.26. [PMID: 23547014 DOI: 10.1002/0471142727.mb2126s102] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Nucleosome displacement is a key event in the regulation of gene expression in the eukaryotic genome. This unit details an approach called Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) for isolating nucleosome-depleted regions. FAIRE does not rely on the use of antibodies or enzymes, and has proven successful in most eukaryotic cells and tissues. The set of regulatory elements enriched by FAIRE is similar to those identified through DNase hypersensitivity. The enriched fragments can be detected by quantitative PCR, tiling DNA microarrays, or next-generation sequencing. Although the signal-to-noise ratio is typically lower than that observed for DNase assays, FAIRE has high sample-to-sample reproducibility, requires very low amounts of input material, is inexpensive, is amenable to high-throughput adaptations, and is a relatively simple procedure with a high rate of success, even for those without extensive experience in molecular biology protocols.
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Affiliation(s)
- Jeremy M Simon
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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218
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Li L, Liu D, Bu D, Chen S, Wu J, Tang C, Du J, Jin H. Brg1-dependent epigenetic control of vascular smooth muscle cell proliferation by hydrogen sulfide. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1347-55. [DOI: 10.1016/j.bbamcr.2013.03.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 03/02/2013] [Accepted: 03/03/2013] [Indexed: 12/19/2022]
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219
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Nelson AC, Wardle FC. Conserved non-coding elements and cis regulation: actions speak louder than words. Development 2013; 140:1385-95. [PMID: 23482485 DOI: 10.1242/dev.084459] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
It is a truth (almost) universally acknowledged that conserved non-coding genomic sequences function in the cis regulation of neighbouring genes. But is this a misconception? The literature is strewn with examples of conserved non-coding sequences being able to drive reporter expression, but the extent to which such sequences are actually used endogenously in vivo is only now being rigorously explored using unbiased genome-scale approaches. Here, we review the emerging picture, examining the extent to which conserved non-coding sequences equivalently regulate gene expression in different species, or at different developmental stages, and how genomics approaches are revealing the relationship between sequence conservation and functional use of cis-regulatory elements.
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Affiliation(s)
- Andrew C Nelson
- Randall Division of Cell and Molecular Biophysics, New Hunt's House, King's College London, Guy's Campus, London SE1 1UL, UK.
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220
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Winter DR, Song L, Mukherjee S, Furey TS, Crawford GE. DNase-seq predicts regions of rotational nucleosome stability across diverse human cell types. Genome Res 2013; 23:1118-29. [PMID: 23657885 PMCID: PMC3698505 DOI: 10.1101/gr.150482.112] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
DNase-seq is primarily used to identify nucleosome-depleted DNase I hypersensitive (DHS) sites genome-wide that correspond to active regulatory elements. However, ∼40 yr ago it was demonstrated that DNase I also digests with a ∼10-bp periodicity around nucleosomes matching the exposure of the DNA minor groove as it wraps around histones. Here, we use DNase-seq data from 49 samples representing diverse cell types to reveal this digestion pattern at individual loci and predict genomic locations where nucleosome rotational positioning, the orientation of DNA with respect to the histone surface, is stably maintained. We call these regions DNase I annotated regions of nucleosome stability (DARNS). Compared to MNase-seq experiments, we show DARNS correspond well to annotated nucleosomes. Interestingly, many DARNS are positioned over only one side of annotated nucleosomes, suggesting that the periodic digestion pattern attenuates over the nucleosome dyad. DARNS reproduce the arrangement of nucleosomes around transcription start sites and are depleted at ubiquitous DHS sites. We also generated DARNS from multiple lymphoblast cell line (LCL) samples. We found that LCL DARNS were enriched at DHS sites present in most of the original 49 samples but absent in LCLs, while multi-cell-type DARNS were enriched at LCL-specific DHS sites. This indicates that variably open DHS sites are often occupied by rotationally stable nucleosomes in cell types where the DHS site is closed. DARNS provide additional information about precise DNA orientation within individual nucleosomes not available from other nucleosome positioning assays and contribute to understanding the role of chromatin in gene regulation.
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Affiliation(s)
- Deborah R Winter
- Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27708, USA
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221
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Yoo EJ, Cooke NE, Liebhaber SA. Identification of a secondary promoter within the human B cell receptor component gene hCD79b. J Biol Chem 2013; 288:18353-65. [PMID: 23649625 DOI: 10.1074/jbc.m113.461988] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The human B cell-specific protein, CD79b (also known as Igβ and B29) constitutes an essential signal transduction component of the B cell receptor. Although its function is central to the triggering of B cell terminal differentiation in response to antigen stimulation, the transcriptional determinants that control CD79b gene expression remain poorly defined. In the present study, we explored these determinants using a series of hCD79b transgenic mouse models. Remarkably, we observed that the previously described hCD79b promoter along with its associated enhancer elements and first exon could be deleted without appreciable loss of hCD79b transcriptional activity or tissue specificity. In this deletion setting, a secondary promoter located within exon 2 maintained full levels and specificity of hCD79b transcription. Of note, this secondary promoter was also active, albeit at lower levels, in the wild-type hCD79b locus. The activity of the secondary promoter was dependent on the action(s) of a conserved sequence element mapping to a chromatin DNase I hypersensitive site located within intron 1. mRNA generated from this secondary promoter is predicted to encode an Igβ protein lacking a signal sequence and thus unable to serve normal B cell receptor function. Although the physiologic role of the hCD79b secondary promoter and its encoded protein remain unclear, the current data suggest that it has the capacity to play a role in normal as well as pathologic states in B cell proliferation and function.
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Affiliation(s)
- Eung Jae Yoo
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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222
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Symmons O, Spitz F. From remote enhancers to gene regulation: charting the genome's regulatory landscapes. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120358. [PMID: 23650632 DOI: 10.1098/rstb.2012.0358] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Vertebrate genes are characterized by the presence of cis-regulatory elements located at great distances from the genes they control. Alterations of these elements have been implicated in human diseases and evolution, yet little is known about how these elements interact with their surrounding sequences. A recent survey of the mouse genome with a regulatory sensor showed that the regulatory activities of these elements are not organized in a gene-centric manner, but instead are broadly distributed along chromosomes, forming large regulatory landscapes with distinct tissue-specific activities. A large genome-wide collection of expression data from this regulatory sensor revealed some basic principles of this complex genome regulatory architecture, including a substantial interplay between enhancers and other types of activities to modulate gene expression. We discuss the implications of these findings for our understanding of non-coding transcription, and of the possible consequences of structural genomic variations in disease and evolution.
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Affiliation(s)
- Orsolya Symmons
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
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223
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Hwang YC, Zheng Q, Gregory BD, Wang LS. High-throughput identification of long-range regulatory elements and their target promoters in the human genome. Nucleic Acids Res 2013; 41:4835-46. [PMID: 23525463 PMCID: PMC3643598 DOI: 10.1093/nar/gkt188] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 02/26/2013] [Accepted: 02/27/2013] [Indexed: 01/05/2023] Open
Abstract
Enhancer elements are essential for tissue-specific gene regulation during mammalian development. Although these regulatory elements are often distant from their target genes, they affect gene expression by recruiting transcription factors to specific promoter regions. Because of this long-range action, the annotation of enhancer element-target promoter pairs remains elusive. Here, we developed a novel analysis methodology that takes advantage of Hi-C data to comprehensively identify these interactions throughout the human genome. To do this, we used a geometric distribution-based model to identify DNA-DNA interaction hotspots that contact gene promoters with high confidence. We observed that these promoter-interacting hotspots significantly overlap with known enhancer-associated histone modifications and DNase I hypersensitive sites. Thus, we defined thousands of candidate enhancer elements by incorporating these features, and found that they have a significant propensity to be bound by p300, an enhancer binding transcription factor. Furthermore, we revealed that their target genes are significantly bound by RNA Polymerase II and demonstrate tissue-specific expression. Finally, we uncovered that these elements are generally found within 1 Mb of their targets, and often regulate multiple genes. In total, our study presents a novel high-throughput workflow for confident, genome-wide discovery of enhancer-target promoter pairs, which will significantly improve our understanding of these regulatory interactions.
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Affiliation(s)
- Yih-Chii Hwang
- Genomics and Computational Biology Graduate Program, University of Pennsylvania, Philadelphia, PA, USA, Department of Biology, University of Pennsylvania, Philadelphia, PA, USA, Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA, USA and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Qi Zheng
- Genomics and Computational Biology Graduate Program, University of Pennsylvania, Philadelphia, PA, USA, Department of Biology, University of Pennsylvania, Philadelphia, PA, USA, Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA, USA and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Brian D. Gregory
- Genomics and Computational Biology Graduate Program, University of Pennsylvania, Philadelphia, PA, USA, Department of Biology, University of Pennsylvania, Philadelphia, PA, USA, Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA, USA and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Li-San Wang
- Genomics and Computational Biology Graduate Program, University of Pennsylvania, Philadelphia, PA, USA, Department of Biology, University of Pennsylvania, Philadelphia, PA, USA, Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia, PA, USA and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
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224
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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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225
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Vadnais C, Awan AA, Harada R, Clermont PL, Leduy L, Bérubé G, Nepveu A. Long-range transcriptional regulation by the p110 CUX1 homeodomain protein on the ENCODE array. BMC Genomics 2013; 14:258. [PMID: 23590133 PMCID: PMC3770232 DOI: 10.1186/1471-2164-14-258] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 03/26/2013] [Indexed: 01/19/2023] Open
Abstract
Background Overexpression of the Cut homeobox 1 gene, CUX1, inversely
correlates with patient survival in breast cancers. Cell-based assays and
molecular studies have revealed that transcriptional regulation by
CUX1 involves mostly the proteolytically processed p110
isoform. As there is no antibody specific to p110 CUX1 only, an alternate
strategy must be employed to identify its targets. Results We expressed physiological levels of a tagged-p110 CUX1 protein and performed
chromatin affinity purification followed by hybridization on ENCODE and
promoter arrays. Targets were validated by chromatin immunoprecipitation and
transcriptional regulation by CUX1 was analyzed in expression profiling and
RT-qPCR assays following CUX1 knockdown or p110 CUX1 overexpression.
Approximately 47% and 14% of CUX1 binding sites were respectively mapped
less than 4 Kbp, or more than 40 Kbp, away from a transcription start site.
More genes exhibited changes in expression following CUX1 knockdown than
p110 CUX1 overexpression. CUX1 directly activated or repressed 7.4% and 8.4%
of putative targets identified on the ENCODE and promoter arrays
respectively. This proportion increased to 11.2% for targets with 2 binding
sites or more. Transcriptional repression was observed in a slightly higher
proportion of target genes. The CUX1 consensus binding motif, ATCRAT, was
found at 47.2% of the CUX1 binding sites, yet only 8.3% of the CUX1
consensus motifs present on the array were bound in vivo. The
presence of a consensus binding motif did not have an impact on whether a
target gene was repressed or activated. Interestingly, the distance between
a binding site and a transcription start site did not significantly reduced
the ability of CUX1 to regulate a target gene. Moreover, CUX1 not only was
able to regulate the next adjacent gene, but also regulated the gene located
beyond this one as well as the gene located further away in the opposite
direction. Conclusion Our results demonstrate that p110 CUX1 can activate or repress transcription
when bound at a distance and can regulate more than one gene on certain
genomic loci.
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Affiliation(s)
- Charles Vadnais
- Goodman Cancer Centre, McGill University, 1160 Pine avenue West, Montreal, Quebec H3A 1A3, Canada
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226
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Simonatto M, Barozzi I, Natoli G. Non-coding transcription at cis-regulatory elements: computational and experimental approaches. Methods 2013; 63:66-75. [PMID: 23542771 DOI: 10.1016/j.ymeth.2013.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/18/2013] [Accepted: 03/20/2013] [Indexed: 12/17/2022] Open
Abstract
Mammalian genomes are pervasively transcribed, generating mostly RNAs with no coding potential that display different size, structure and interspecies sequence conservation. A prominent contribution to the ncRNA pool comes from the transcription of cis-regulatory elements, namely promoters, enhancers and locus control regions. While this phenomenon has been extensively documented, possible roles of such ncRNAs in gene regulation are still unclear. Addressing this issue will require experimental strategies dealing with the low abundance of enhancer-templated ncRNAs and aimed at specifically dissecting the relative role of transcription per se vs. RNA products. In this review, we first focus on the identification and characterization of cis-regulatory elements, highlighting the differences between emerging classes of ncRNAs associated to specific chromatin signatures. We then discuss current experimental strategies to dissect the function of nc transcription and computational approaches to the analysis and classification of regulatory sequences identified in next-generation sequencing experiments.
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Affiliation(s)
- Marta Simonatto
- Department of Experimental Oncology, European Institute of Oncology (IEO), Via Adamello 16, 20139 Milan, Italy.
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227
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Witham J, Ouboussad L, Lefevre PF. A NF-κB-dependent dual promoter-enhancer initiates the lipopolysaccharide-mediated transcriptional activation of the chicken lysozyme in macrophages. PLoS One 2013; 8:e59389. [PMID: 23533622 PMCID: PMC3606415 DOI: 10.1371/journal.pone.0059389] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 02/14/2013] [Indexed: 02/06/2023] Open
Abstract
The transcriptional activation of the chicken lysozyme gene (cLys) by lipopolysaccharide (LPS) in macrophages is dependent on transcription of a LPS-Inducible Non-Coding RNA (LINoCR) triggering eviction of the CCCTC-binding factor (CTCF) from a negative regulatory element upstream of the lysozyme transcription start site. LINoCR is transcribed from a promoter originally characterized as a hormone response enhancer in the oviduct. Herein, we report the characterization of this cis-regulatory element (CRE). In activated macrophages, a 60 bp region bound by NF-κB, AP1 and C/EBPβ controls this CRE, which is strictly dependent on NF-κB binding for its activity in luciferase assays. Moreover, the serine/threonine kinase IKKα, known to be recruited by NF-κB to NF-κB-dependent genes is found at the CRE and within the transcribing regions of both cLys and LINoCR. Such repartition suggests a simultaneous promoter and enhancer activity of this CRE, initiating cLys transcriptional activation and driving CTCF eviction. This recruitment was transient despite persistence of both cLys transcription and NF-κB binding to the CRE. Finally, comparing cLys with other LPS-inducible genes indicates that IKKα detection within transcribing regions can be correlated with the presence of the elongating form of RNA polymerase II or concentrated in the 3′ end of the gene.
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Affiliation(s)
- James Witham
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Wellcome Trust Brenner Building, St. James’s University Hospital, Leeds, United Kingdom
| | - Lylia Ouboussad
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Wellcome Trust Brenner Building, St. James’s University Hospital, Leeds, United Kingdom
| | - Pascal F. Lefevre
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Wellcome Trust Brenner Building, St. James’s University Hospital, Leeds, United Kingdom
- * E-mail:
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228
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Latent enhancers activated by stimulation in differentiated cells. Cell 2013; 152:157-71. [PMID: 23332752 DOI: 10.1016/j.cell.2012.12.018] [Citation(s) in RCA: 584] [Impact Index Per Article: 53.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 10/12/2012] [Accepted: 12/13/2012] [Indexed: 01/27/2023]
Abstract
According to current models, once the cell has reached terminal differentiation, the enhancer repertoire is completely established and maintained by cooperatively acting lineage-specific transcription factors (TFs). TFs activated by extracellular stimuli operate within this predetermined repertoire, landing close to where master regulators are constitutively bound. Here, we describe latent enhancers, defined as regions of the genome that in terminally differentiated cells are unbound by TFs and lack the histone marks characteristic of enhancers but acquire these features in response to stimulation. Macrophage stimulation caused sequential binding of stimulus-activated and lineage-determining TFs to these regions, enabling deposition of enhancer marks. Once unveiled, many of these enhancers did not return to a latent state when stimulation ceased; instead, they persisted and mediated a faster and stronger response upon restimulation. We suggest that stimulus-specific expansion of the cis-regulatory repertoire provides an epigenomic memory of the exposure to environmental agents.
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229
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Calo E, Wysocka J. Modification of enhancer chromatin: what, how, and why? Mol Cell 2013; 49:825-37. [PMID: 23473601 PMCID: PMC3857148 DOI: 10.1016/j.molcel.2013.01.038] [Citation(s) in RCA: 998] [Impact Index Per Article: 90.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/28/2013] [Accepted: 01/30/2013] [Indexed: 01/01/2023]
Abstract
Emergence of form and function during embryogenesis arises in large part through cell-type- and cell-state-specific variation in gene expression patterns, mediated by specialized cis-regulatory elements called enhancers. Recent large-scale epigenomic mapping revealed unexpected complexity and dynamics of enhancer utilization patterns, with 400,000 putative human enhancers annotated by the ENCODE project alone. These large-scale efforts were largely enabled through the understanding that enhancers share certain stereotypical chromatin features. However, an important question still lingers: what is the functional significance of enhancer chromatin modification? Here we give an overview of enhancer-associated modifications of histones and DNA and discuss enzymatic activities involved in their dynamic deposition and removal. We describe potential downstream effectors of these marks and propose models for exploring functions of chromatin modification in regulating enhancer activity during development.
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Affiliation(s)
- Eliezer Calo
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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230
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Vahedi G, Poholek A, Hand TW, Laurence A, Kann Y, O’Shea JJ, Hirahara K. Helper T-cell identity and evolution of differential transcriptomes and epigenomes. Immunol Rev 2013; 252:24-40. [PMID: 23405893 PMCID: PMC3577092 DOI: 10.1111/imr.12037] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
CD4(+) T cells are critical for the elimination of an immense array of microbial pathogens. Among the ways they accomplish this task is to generate progeny with specialized, characteristic patterns of gene expression. From this perspective, helper cells can be viewed as pluripotent precursors that adopt distinct cell fates. Although there are aspects of helper cell differentiation that can be modeled as a classic cell fate commitment, CD4(+) T cells also maintain considerable flexibility in their transcriptional program. This makes sense in terms of host defense, but raises the question of how these remarkable cells balance both these requirements, a high degree of specific gene expression and the capacity for plasticity. In this review, we discuss recent advances in our understanding of CD4(+) T-cell specification, focusing on how genomic perspectives have influenced our views of these processes. The relative contributions of sensors of the cytokine milieu, especially the signal transducer and activator of transcription family transcription factors, 'master regulators', and other transcription factors are considered as they relate to the helper cell transcriptome and epigenome.
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Affiliation(s)
- Golnaz Vahedi
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - Amanda Poholek
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - Timothy W. Hand
- Laboratory of parasitic diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Arian Laurence
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - Yuka Kann
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - John J. O’Shea
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - Kiyoshi Hirahara
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
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231
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Glidewell-Kenney CA, Shao PP, Iyer AK, Grove AMH, Meadows JD, Mellon PL. Neurokinin B causes acute GnRH secretion and repression of GnRH transcription in GT1-7 GnRH neurons. Mol Endocrinol 2013; 27:437-54. [PMID: 23393128 DOI: 10.1210/me.2012-1271] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Genetic studies in human patients with idiopathic hypogonadotropic hypogonadism (IHH) identified mutations in the genes that encode neurokinin B (NKB) and the neurokinin 3 receptor (NK3R). However, determining the mechanism whereby NKB regulates gonadotropin secretion has been difficult because of conflicting results from in vivo studies investigating the luteinizing hormone (LH) response to senktide, a NK3R agonist. NK3R is expressed in a subset of GnRH neurons and in kisspeptin neurons that are known to regulate GnRH secretion. Thus, one potential source of inconsistency is that NKB could produce opposing direct and indirect effects on GnRH secretion. Here, we employ the GT1-7 cell model to elucidate the direct effects of NKB on GnRH neuron function. We find that GT1-7 cells express NK3R and respond to acute senktide treatment with c-Fos induction and increased GnRH secretion. In contrast, long-term senktide treatment decreased GnRH secretion. Next, we focus on the examination of the mechanism underlying the long-term decrease in secretion and determine that senktide treatment represses transcription of GnRH. We further show that this repression of GnRH transcription may involve enhanced c-Fos protein binding at novel activator protein-1 (AP-1) half-sites identified in enhancer 1 and the promoter, as well as chromatin remodeling at the promoter of the GnRH gene. These data indicate that NKB could directly regulate secretion from NK3R-expressing GnRH neurons. Furthermore, whether the response is inhibitory or stimulatory toward GnRH secretion could depend on the history or length of exposure to NKB because of a repressive effect on GnRH transcription.
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Affiliation(s)
- Christine A Glidewell-Kenney
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA 92093-0674, USA
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232
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Vernot B, Stergachis AB, Maurano MT, Vierstra J, Neph S, Thurman RE, Stamatoyannopoulos JA, Akey JM. Personal and population genomics of human regulatory variation. Genome Res 2013; 22:1689-97. [PMID: 22955981 PMCID: PMC3431486 DOI: 10.1101/gr.134890.111] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The characteristics and evolutionary forces acting on regulatory variation in humans remains elusive because of the difficulty in defining functionally important noncoding DNA. Here, we combine genome-scale maps of regulatory DNA marked by DNase I hypersensitive sites (DHSs) from 138 cell and tissue types with whole-genome sequences of 53 geographically diverse individuals in order to better delimit the patterns of regulatory variation in humans. We estimate that individuals likely harbor many more functionally important variants in regulatory DNA compared with protein-coding regions, although they are likely to have, on average, smaller effect sizes. Moreover, we demonstrate that there is significant heterogeneity in the level of functional constraint in regulatory DNA among different cell types. We also find marked variability in functional constraint among transcription factor motifs in regulatory DNA, with sequence motifs for major developmental regulators, such as HOX proteins, exhibiting levels of constraint comparable to protein-coding regions. Finally, we perform a genome-wide scan of recent positive selection and identify hundreds of novel substrates of adaptive regulatory evolution that are enriched for biologically interesting pathways such as melanogenesis and adipocytokine signaling. These data and results provide new insights into patterns of regulatory variation in individuals and populations and demonstrate that a large proportion of functionally important variation lies beyond the exome.
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Affiliation(s)
- Benjamin Vernot
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA
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233
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Schaub MA, Boyle AP, Kundaje A, Batzoglou S, Snyder M. Linking disease associations with regulatory information in the human genome. Genome Res 2013; 22:1748-59. [PMID: 22955986 PMCID: PMC3431491 DOI: 10.1101/gr.136127.111] [Citation(s) in RCA: 536] [Impact Index Per Article: 48.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Genome-wide association studies have been successful in identifying single nucleotide polymorphisms (SNPs) associated with a large number of phenotypes. However, an associated SNP is likely part of a larger region of linkage disequilibrium. This makes it difficult to precisely identify the SNPs that have a biological link with the phenotype. We have systematically investigated the association of multiple types of ENCODE data with disease-associated SNPs and show that there is significant enrichment for functional SNPs among the currently identified associations. This enrichment is strongest when integrating multiple sources of functional information and when highest confidence disease-associated SNPs are used. We propose an approach that integrates multiple types of functional data generated by the ENCODE Consortium to help identify “functional SNPs” that may be associated with the disease phenotype. Our approach generates putative functional annotations for up to 80% of all previously reported associations. We show that for most associations, the functional SNP most strongly supported by experimental evidence is a SNP in linkage disequilibrium with the reported association rather than the reported SNP itself. Our results show that the experimental data sets generated by the ENCODE Consortium can be successfully used to suggest functional hypotheses for variants associated with diseases and other phenotypes.
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Affiliation(s)
- Marc A Schaub
- Department of Computer Science, Stanford University, Stanford, California 94305, USA
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234
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Codrington AM, Hales BF, Robaire B. Spermiogenic Germ Cell Phase-Specific DNA Damage Following Cyclophosphamide Exposure. ACTA ACUST UNITED AC 2013; 25:354-62. [PMID: 15064312 DOI: 10.1002/j.1939-4640.2004.tb02800.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The production of genetically competent spermatozoa is essential for normal embryo development. The chemotherapeutic drug cyclophosphamide creates cross-links and DNA strand breaks in many cell types, including germ cells. This study assessed the phase specificity of the susceptibility of spermiogenic germ cells to genetic damage induced by cyclophosphamide. Adult male rats were given cyclophosphamide using one of four schedules: 1) high dose/acute- day 1, 100 mg/kg; 2) low dose/subchronic, 4 days-days 1-4, 6.0 mg/kg/d; 3) high dose/subchronic, 4 days-day 1, 100 mg/kg, and days 2-4, 50 mg/kg/d; and 4) low dose/chronic-daily, 6.0 mg/kg/d for 14-28 days. To capture cauda epididymal spermatozoa exposed to cyclophosphamide during late, mid-, and early spermiogenesis, animals were sacrificed on days 14, 21, and 28, respectively. Spermatozoa were analyzed for DNA strand breaks using the comet assay. No dramatic increases in damage were seen after high-dose/acute exposure to cyclophosphamide. Subchronic exposure showed a dose-related increase in DNA damage; maximal damage, as demonstrated by comet tail parameters, was seen after 21 days, reflecting an increased susceptibility of step 9-14 spermatids. Low-dose chronic exposure to cyclophosphamide induced DNA damage, which reached a plateau by day 21. The magnitude of damage at all time points after low-dose chronic exposure was much greater than that following low-dose exposure for 4 days, indicating an accumulation of damage over time. Thus, the DNA damage induced by cyclophosphamide is germ cell phase-specific. The most damaging effects of cyclophosphamide occurred during a key point of sperm chromatin remodeling (histone hyperacetylation and transition protein deposition). We speculate that strand breaks disrupt chromatin remodeling, hence affecting chromatin structure and embryo development.
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Affiliation(s)
- Alexis M Codrington
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
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235
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Ling G, Waxman DJ. Isolation of nuclei for use in genome-wide DNase hypersensitivity assays to probe chromatin structure. Methods Mol Biol 2013; 977:13-9. [PMID: 23436350 PMCID: PMC3815455 DOI: 10.1007/978-1-62703-284-1_2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
DNase hypersensitivity (DHS) analysis coupled with high-throughput DNA sequencing (DNase-seq) has emerged as a powerful tool to analyze chromatin accessibility and identify regulatory sequences in genomic DNA on a global scale. In this method, intact nuclei are isolated from fresh tissue or cultured cells and then subjected to limited digestion using DNase I. The resulting short DNA fragments released by DNase digestion, which correspond to regions of open chromatin structure, are subsequently purified and identified by high throughput next generation DNA sequencing. This chapter describes methods used to isolate intact nuclei from mouse liver suitable for DNase-seq studies. The following chapter presents a detailed protocol for DNase I digestion of liver nuclei followed by the isolation of DNase-released fragments for sequencing and genome-wide mapping of DHS sites.
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Affiliation(s)
- Guoyu Ling
- Dept. of Biology, Boston University, Boston, MA 02215, USA
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236
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Abstract
This review concisely highlights the complexity of regulatory events. It provides examples of how interconnectivity of regulatory hubs could maintain transcriptional synergy and orchestrate the proper spatial and temporal patterns of gene expression.
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Affiliation(s)
- Minou Bina
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
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237
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Upstream distal regulatory elements contact the Lmo2 promoter in mouse erythroid cells. PLoS One 2012; 7:e52880. [PMID: 23285212 PMCID: PMC3528669 DOI: 10.1371/journal.pone.0052880] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 11/22/2012] [Indexed: 01/06/2023] Open
Abstract
The Lim domain only 2 (Lmo2) gene encodes a transcriptional cofactor critical for the development of hematopoietic stem cells. Several distal regulatory elements have been identified upstream of the Lmo2 gene in the human and mouse genomes that are capable of enhancing reporter gene expression in erythroid cells and may be responsible for the high level transcription of Lmo2 in the erythroid lineage. In this study we investigate how these elements regulate transcription of Lmo2 and whether or not they function cooperatively in the endogenous context. Chromosome conformation capture (3C) experiments show that chromatin-chromatin interactions exist between upstream regulatory elements and the Lmo2 promoter in erythroid cells but that these interactions are absent from kidney where Lmo2 is transcribed at twelve fold lower levels. Specifically, long range chromatin-chromatin interactions occur between the Lmo2 proximal promoter and two broad regions, 3–31 and 66–105 kb upstream of Lmo2, which we term the proximal and distal control regions for Lmo2 (pCR and dCR respectively). Each of these regions is bound by several transcription factors suggesting that multiple regulatory elements cooperate in regulating high level transcription of Lmo2 in erythroid cells. Binding of CTCF and cohesin which support chromatin loops at other loci were also found within the dCR and at the Lmo2 proximal promoter. Intergenic transcription occurs throughout the dCR in erythroid cells but not in kidney suggesting a role for these intergenic transcripts in regulating Lmo2, similar to the broad domain of intergenic transcription observed at the human β-globin locus control region. Our data supports a model in which the dCR functions through a chromatin looping mechanism to contact and enhance Lmo2 transcription specifically in erythroid cells. Furthermore, these chromatin loops are supported by the cohesin complex recruited to both CTCF and transcription factor bound regions.
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238
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Nair SS, Kumar R. Chromatin remodeling in cancer: a gateway to regulate gene transcription. Mol Oncol 2012; 6:611-9. [PMID: 23127546 PMCID: PMC3538127 DOI: 10.1016/j.molonc.2012.09.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 09/30/2012] [Indexed: 01/01/2023] Open
Abstract
Cancer cells are remarkably adaptive to diverse survival strategies, probably due to its ability to interpret signaling cues differently than the normal cells. It appears as if cancer cells are constantly sampling, selecting and adapting signaling pathways to favor its proliferation. This process of successful adaptive evolution eventually renders a retractile nature to therapeutic regimens, fueling to the process of cancer progression. Based on plethora of available information, it is now evident that multiple signaling pathways eventually converge, perhaps, in a tempo-spatial manner, onto DNA template-dependent dynamic processes. Considering the complexity and packaging of eukaryotic genome, this process involves energy-dependent sub-events mediated by chromatin remodelers. Chromatin remodeler proteins function as gatekeepers and constitute a major determinant of accessibility of accessory factors to nucleosome DNA, allowing a wide repertoire of biological functions. And thus, aberrant expression or epigenetic modulation of remodeler proteins confers a unique ability to cancer cells to reprogram its genome for the maintenance of oncogenic phenotypes. Cancer cells can uniquely select a multi-subunit remodeler proteome for oncogenic advantage. This review summarizes our current understanding and importance of remodeler and chromatin proteins in cancer biology and also highlights the paradoxical role of proteins with or without dual-regulator functions. It is our hope that an in-depth understanding of these events is likely to provide a next set of opportunities for novel strategies for targeted cancer therapeutics.
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Affiliation(s)
- Sujit S Nair
- Department of Biochemistry and Molecular Biology, The McCormick Genomic and Proteomic Center, The School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA
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239
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Fingerman IM, Zhang X, Ratzat W, Husain N, Cohen RF, Schuler GD. NCBI Epigenomics: what's new for 2013. Nucleic Acids Res 2012. [PMID: 23193265 PMCID: PMC3531100 DOI: 10.1093/nar/gks1171] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The Epigenomics resource at the National Center for Biotechnology Information (NCBI) has been created to serve as a comprehensive public repository for whole-genome epigenetic data sets (www.ncbi.nlm.nih.gov/epigenomics). We have constructed this resource by selecting the subset of epigenetics-specific data from the Gene Expression Omnibus (GEO) database and then subjecting them to further review and annotation. Associated data tracks can be viewed using popular genome browsers or downloaded for local analysis. We have performed extensive user testing throughout the development of this resource, and new features and improvements are continuously being implemented based on the results. We have made substantial usability improvements to user interfaces, enhanced functionality, made identification of data tracks of interest easier and created new tools for preliminary data analyses. Additionally, we have made efforts to enhance the integration between the Epigenomics resource and other NCBI databases, including the Gene database and PubMed. Data holdings have also increased dramatically since the initial publication describing the NCBI Epigenomics resource and currently consist of >3700 viewable and downloadable data tracks from 955 biological sources encompassing five well-studied species. This updated manuscript highlights these changes and improvements.
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Affiliation(s)
- Ian M Fingerman
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, 45 Center Drive, Bethesda, MD 20892, USA.
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240
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Marsman J, Horsfield JA. Long distance relationships: enhancer-promoter communication and dynamic gene transcription. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:1217-27. [PMID: 23124110 DOI: 10.1016/j.bbagrm.2012.10.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 10/18/2012] [Accepted: 10/22/2012] [Indexed: 11/27/2022]
Abstract
The three-dimensional regulation of gene transcription involves loop formation between enhancer and promoter elements, controlling spatiotemporal gene expression in multicellular organisms. Enhancers are usually located in non-coding DNA and can activate gene transcription by recruiting transcription factors, chromatin remodeling factors and RNA Polymerase II. Research over the last few years has revealed that enhancers have tell-tale characteristics that facilitate their detection by several approaches, although the hallmarks of enhancers are not always uniform. Enhancers likely play an important role in the activation of genes by functioning as a primary point of contact for transcriptional activators, and by making physical contact with gene promoters often by means of a chromatin loop. Although numerous transcriptional regulators participate in the formation of chromatin loops that bring enhancers into proximity with promoters, the mechanism(s) of enhancer-promoter connectivity remain enigmatic. Here we discuss enhancer function, review some of the many proteins shown to be involved in establishing enhancer-promoter loops, and describe the dynamics of enhancer-promoter contacts during development, differentiation and in specific cell types.
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Affiliation(s)
- Judith Marsman
- Department of Pathology, The University of Otago, Dunedin, New Zealand
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241
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ChIP-seq and beyond: new and improved methodologies to detect and characterize protein-DNA interactions. Nat Rev Genet 2012; 13:840-52. [PMID: 23090257 DOI: 10.1038/nrg3306] [Citation(s) in RCA: 485] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chromatin immunoprecipitation experiments followed by sequencing (ChIP-seq) detect protein-DNA binding events and chemical modifications of histone proteins. Challenges in the standard ChIP-seq protocol have motivated recent enhancements in this approach, such as reducing the number of cells that are required and increasing the resolution. Complementary experimental approaches - for example, DNaseI hypersensitive site mapping and analysis of chromatin interactions that are mediated by particular proteins - provide additional information about DNA-binding proteins and their function. These data are now being used to identify variability in the functions of DNA-binding proteins across genomes and individuals. In this Review, I describe the latest advances in methods to detect and functionally characterize DNA-bound proteins.
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242
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Sheffield NC, Furey TS. Identifying and characterizing regulatory sequences in the human genome with chromatin accessibility assays. Genes (Basel) 2012; 3:651-70. [PMID: 24705081 PMCID: PMC3899983 DOI: 10.3390/genes3040651] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 08/17/2012] [Accepted: 09/25/2012] [Indexed: 01/11/2023] Open
Abstract
After finishing a human genome reference sequence in 2002, the genomics community has turned to the task of interpreting it. A primary focus is to identify and characterize not only protein-coding genes, but all functional elements in the genome. The effort includes both individual investigators and large-scale projects like the Encyclopedia of DNA Elements (ENCODE) project. As part of the ENCODE project, several groups have identified millions of regulatory elements in hundreds of human cell-types using DNase-seq and FAIRE-seq experiments that detect regions of nucleosome-free open chromatin. ChIP-seq experiments have also been used to discover transcription factor binding sites and map histone modifications. Nearly all identified elements are found in non-coding DNA, hypothesizing a function for previously unannotated sequence. In this review, we provide an overview of the ENCODE effort to define regulatory elements, summarize the main results, and discuss implications of the millions of regulatory elements distributed throughout the genome.
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Affiliation(s)
- Nathan C Sheffield
- Program in Computational Biology and Bioinformatics, Institute for Genome Sciences & Policy, Duke University, Durham, NC 27708, USA.
| | - Terrence S Furey
- Depts of Genetics and Biology, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
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243
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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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244
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Tewari AK, Yardimci GG, Shibata Y, Sheffield NC, Song L, Taylor BS, Georgiev SG, Coetzee GA, Ohler U, Furey TS, Crawford GE, Febbo PG. Chromatin accessibility reveals insights into androgen receptor activation and transcriptional specificity. Genome Biol 2012; 13:R88. [PMID: 23034120 PMCID: PMC3491416 DOI: 10.1186/gb-2012-13-10-r88] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 08/14/2012] [Accepted: 10/03/2012] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Epigenetic mechanisms such as chromatin accessibility impact transcription factor binding to DNA and transcriptional specificity. The androgen receptor (AR), a master regulator of the male phenotype and prostate cancer pathogenesis, acts primarily through ligand-activated transcription of target genes. Although several determinants of AR transcriptional specificity have been elucidated, our understanding of the interplay between chromatin accessibility and AR function remains incomplete. RESULTS We used deep sequencing to assess chromatin structure via DNase I hypersensitivity and mRNA abundance, and paired these datasets with three independent AR ChIP-seq datasets. Our analysis revealed qualitative and quantitative differences in chromatin accessibility that corresponded to both AR binding and an enrichment of motifs for potential collaborating factors, one of which was identified as SP1. These quantitative differences were significantly associated with AR-regulated mRNA transcription across the genome. Base-pair resolution of the DNase I cleavage profile revealed three distinct footprinting patterns associated with the AR-DNA interaction, suggesting multiple modes of AR interaction with the genome. CONCLUSIONS In contrast with other DNA-binding factors, AR binding to the genome does not only target regions that are accessible to DNase I cleavage prior to hormone induction. AR binding is invariably associated with an increase in chromatin accessibility and, consequently, changes in gene expression. Furthermore, we present the first in vivo evidence that a significant fraction of AR binds only to half of the full AR DNA motif. These findings indicate a dynamic quantitative relationship between chromatin structure and AR-DNA binding that impacts AR transcriptional specificity.
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Affiliation(s)
- Alok K Tewari
- Institute for Genome Sciences & Policy, Duke University, Durham, NC 27708, USA
| | | | - Yoichiro Shibata
- Institute for Genome Sciences & Policy, Duke University, Durham, NC 27708, USA
| | - Nathan C Sheffield
- Institute for Genome Sciences & Policy, Duke University, Durham, NC 27708, USA
| | - Lingyun Song
- Institute for Genome Sciences & Policy, Duke University, Durham, NC 27708, USA
| | - Barry S Taylor
- Computational Biology Center, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Stoyan G Georgiev
- Institute for Genome Sciences & Policy, Duke University, Durham, NC 27708, USA
| | - Gerhard A Coetzee
- Department of Preventive Medicine, Norris Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Urology, Norris Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Uwe Ohler
- Institute for Genome Sciences & Policy, Duke University, Durham, NC 27708, USA
- Department of Biostatistics and Bioinformatics, Duke University, Durham, NC 27708, USA
- Department of Computer Science, Duke University, Durham, NC 27708, USA
| | - Terrence S Furey
- Departments of Biology and Genetics, Carolina Center for Genome Sciences and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Gregory E Crawford
- Institute for Genome Sciences & Policy, Duke University, Durham, NC 27708, USA
- Department of Pediatrics, Division of Medical Genetics, Duke University, Durham, NC 27708, USA
| | - Phillip G Febbo
- Helen Diller Family Comprehensive Cancer Center, University of California at San Francisco, San Francisco, CA 94115, USA
- Department of Medicine, University of California at San Francisco School of Medicine, San Francisco, CA 94115, USA
- Department of Urology, University of California at San Francisco School of Medicine, San Francisco, CA 94115, USA
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245
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Vinckevicius A, Chakravarti D. Chromatin immunoprecipitation: advancing analysis of nuclear hormone signaling. J Mol Endocrinol 2012; 49:R113-23. [PMID: 22872135 PMCID: PMC3839787 DOI: 10.1530/jme-12-0016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Recent decades have been filled with groundbreaking research in the field of endocrine hormone signaling. Pivotal events like the isolation and purification of the estrogen receptor, the cloning of glucocorticoid receptor cDNA, or dissemination of nuclear hormone receptor (NHR) DNA binding sequences are well recognized for their contributions. However, the novel genome-wide and gene-specific information obtained over the last decade describing NHR association with chromatin, cofactors, and epigenetic modifications, as well as their role in gene regulation, has been largely facilitated by the adaptation of the chromatin immunoprecipitation (ChIP) technique. Use of ChIP-based technologies has taken the field of hormone signaling from speculating about the transcription-enabling properties of acetylated chromatin and putative transcription (co-)factor genomic occupancy to demonstrating the detailed, stepwise mechanisms of factor binding and transcriptional initiation; from treating hormone-induced transcription as a steady-state event to understanding its dynamic and cyclic nature; from looking at the DNA sequences recognized by various DNA-binding domains in vitro to analyzing the cell-specific genome-wide pattern of nuclear receptor binding and interpreting its physiological implications. Not only have these events propelled hormone research, but, as some of the pioneering studies, have also contributed tremendously to the field of molecular endocrinology as a whole. In this review, we give a brief summary of some of the most important discoveries in hormone signaling using ChIP and other derivative techniques and speculate on what the future may hold.
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Affiliation(s)
- Aurimas Vinckevicius
- Division of Reproductive Biology Research, Department of Obstetrics and Gynecology, Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, 303 East Superior Street, Lurie 4-119, Chicago, Illinois 60611, USA
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246
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Chen X, Chen Z, Chen H, Su Z, Yang J, Lin F, Shi S, He X. Nucleosomes suppress spontaneous mutations base-specifically in eukaryotes. Science 2012; 335:1235-8. [PMID: 22403392 DOI: 10.1126/science.1217580] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
It is unknown how the composition and structure of DNA within the cell affect spontaneous mutations. Theory suggests that in eukaryotic genomes, nucleosomal DNA undergoes fewer C→T mutations because of suppressed cytosine hydrolytic deamination relative to nucleosome-depleted DNA. Comparative genomic analyses and a mutation accumulation experiment showed that nucleosome occupancy nearly eliminated cytosine deamination, resulting in an ~50% decrease of the C→T mutation rate in nucleosomal DNA. Furthermore, the rates of G→T and A→T mutations were also about twofold suppressed by nucleosomes. On the basis of these results, we conclude that nucleosome-dependent mutation spectra affect eukaryotic genome structure and evolution and may have implications for understanding the origin of mutations in cancers and in induced pluripotent stem cells.
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Affiliation(s)
- Xiaoshu Chen
- State Key Laboratory of Bio-control, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
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247
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Thurman RE, Rynes E, Humbert R, Vierstra J, Maurano MT, Haugen E, Sheffield NC, Stergachis AB, Wang H, Vernot B, Garg K, Sandstrom R, Bates D, Canfield TK, Diegel M, Dunn D, Ebersol AK, Frum T, Giste E, Harding L, Johnson AK, Johnson EM, Kutyavin T, Lajoie B, Lee BK, Lee K, London D, Lotakis D, Neph S, Neri F, Nguyen ED, Reynolds AP, Roach V, Safi A, Sanchez ME, Sanyal A, Shafer A, Simon JM, Song L, Vong S, Weaver M, Zhang Z, Zhang Z, Lenhard B, Tewari M, Dorschner MO, Hansen RS, Navas PA, Stamatoyannopoulos G, Iyer VR, Lieb JD, Sunyaev SR, Akey JM, Sabo PJ, Kaul R, Furey TS, Dekker J, Crawford GE, Stamatoyannopoulos JA. The accessible chromatin landscape of the human genome. Nature 2012; 489:75-82. [PMID: 22955617 PMCID: PMC3721348 DOI: 10.1038/nature11232] [Citation(s) in RCA: 1919] [Impact Index Per Article: 159.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 05/15/2012] [Indexed: 02/07/2023]
Abstract
DNase I hypersensitive sites (DHSs) are markers of regulatory DNA and have underpinned the discovery of all classes of cis-regulatory elements including enhancers, promoters, insulators, silencers and locus control regions. Here we present the first extensive map of human DHSs identified through genome-wide profiling in 125 diverse cell and tissue types. We identify ∼2.9 million DHSs that encompass virtually all known experimentally validated cis-regulatory sequences and expose a vast trove of novel elements, most with highly cell-selective regulation. Annotating these elements using ENCODE data reveals novel relationships between chromatin accessibility, transcription, DNA methylation and regulatory factor occupancy patterns. We connect ∼580,000 distal DHSs with their target promoters, revealing systematic pairing of different classes of distal DHSs and specific promoter types. Patterning of chromatin accessibility at many regulatory regions is organized with dozens to hundreds of co-activated elements, and the transcellular DNase I sensitivity pattern at a given region can predict cell-type-specific functional behaviours. The DHS landscape shows signatures of recent functional evolutionary constraint. However, the DHS compartment in pluripotent and immortalized cells exhibits higher mutation rates than that in highly differentiated cells, exposing an unexpected link between chromatin accessibility, proliferative potential and patterns of human variation.
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Affiliation(s)
- Robert E. Thurman
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Eric Rynes
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Richard Humbert
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Jeff Vierstra
- Department of Genome Sciences, University of Washington, Seattle, WA
| | | | - Eric Haugen
- Department of Genome Sciences, University of Washington, Seattle, WA
| | | | | | - Hao Wang
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Benjamin Vernot
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Kavita Garg
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Richard Sandstrom
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Daniel Bates
- Department of Genome Sciences, University of Washington, Seattle, WA
| | | | - Morgan Diegel
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Douglas Dunn
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Abigail K. Ebersol
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Tristan Frum
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Erika Giste
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Lisa Harding
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Audra K. Johnson
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Ericka M. Johnson
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Tanya Kutyavin
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Bryan Lajoie
- Program in Gene Function, University of Massachusetts Medical School, Worcester, MA
| | - Bum-Kyu Lee
- Institute for Cellular and Molecular Biology, University of Texas, Austin, TX
| | - Kristen Lee
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Darin London
- Institute for Genome Sciences and Policy, Duke University, Durham, NC
| | - Dimitra Lotakis
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Shane Neph
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Fidencio Neri
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Eric D. Nguyen
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Alex P. Reynolds
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Vaughn Roach
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Alexias Safi
- Institute for Genome Sciences and Policy, Duke University, Durham, NC
| | - Minerva E. Sanchez
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Amartya Sanyal
- Program in Gene Function, University of Massachusetts Medical School, Worcester, MA
| | - Anthony Shafer
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Jeremy M. Simon
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Lingyun Song
- Institute for Genome Sciences and Policy, Duke University, Durham, NC
| | - Shinny Vong
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Molly Weaver
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Zhancheng Zhang
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Zhuzhu Zhang
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Boris Lenhard
- Bergen Center for Computational Science, University of Bergen, Bergen, Norway
| | - Muneesh Tewari
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Michael O. Dorschner
- Dept. of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA
| | - R. Scott Hansen
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Patrick A. Navas
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | | | - Vishwanath R. Iyer
- Institute for Cellular and Molecular Biology, University of Texas, Austin, TX
| | - Jason D. Lieb
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Shamil R. Sunyaev
- Dept. of Medicine, Division of Genetics, Brigham & Women’s Hospital and Harvard Medical School, Boston, MA
| | - Joshua M. Akey
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Peter J. Sabo
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Rajinder Kaul
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Terrence S. Furey
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Job Dekker
- Program in Gene Function, University of Massachusetts Medical School, Worcester, MA
| | | | - John A. Stamatoyannopoulos
- Department of Genome Sciences, University of Washington, Seattle, WA
- Department of Medicine, Division of Oncology, University of Washington, Seattle, WA
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248
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Neph S, Vierstra J, Stergachis AB, Reynolds AP, Haugen E, Vernot B, Thurman RE, Sandstrom R, Johnson AK, Maurano MT, Humbert R, Rynes E, Wang H, Vong S, Lee K, Bates D, Diegel M, Roach V, Dunn D, Neri J, Schafer A, Hansen RS, Kutyavin T, Giste E, Weaver M, Canfield T, Sabo P, Zhang M, Balasundaram G, Byron R, MacCoss MJ, Akey JM, Bender M, Groudine M, Kaul R, Stamatoyannopoulos JA. An expansive human regulatory lexicon encoded in transcription factor footprints. Nature 2012; 489:83-90. [PMID: 22955618 PMCID: PMC3736582 DOI: 10.1038/nature11212] [Citation(s) in RCA: 566] [Impact Index Per Article: 47.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Accepted: 05/10/2012] [Indexed: 01/04/2023]
Abstract
Regulatory factor binding to genomic DNA protects the underlying sequence from cleavage by DNase I, leaving nucleotide-resolution footprints. Using genomic DNase I footprinting across 41 diverse cell and tissue types, we detected 45 million transcription factor occupancy events within regulatory regions, representing differential binding to 8.4 million distinct short sequence elements. Here we show that this small genomic sequence compartment, roughly twice the size of the exome, encodes an expansive repertoire of conserved recognition sequences for DNA-binding proteins that nearly doubles the size of the human cis-regulatory lexicon. We find that genetic variants affecting allelic chromatin states are concentrated in footprints, and that these elements are preferentially sheltered from DNA methylation. High-resolution DNase I cleavage patterns mirror nucleotide-level evolutionary conservation and track the crystallographic topography of protein-DNA interfaces, indicating that transcription factor structure has been evolutionarily imprinted on the human genome sequence. We identify a stereotyped 50-base-pair footprint that precisely defines the site of transcript origination within thousands of human promoters. Finally, we describe a large collection of novel regulatory factor recognition motifs that are highly conserved in both sequence and function, and exhibit cell-selective occupancy patterns that closely parallel major regulators of development, differentiation and pluripotency.
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Affiliation(s)
- Shane Neph
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Jeff Vierstra
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | | | - Alex P. Reynolds
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Eric Haugen
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Benjamin Vernot
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Robert E. Thurman
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Richard Sandstrom
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Audra K. Johnson
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Matthew T. Maurano
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Richard Humbert
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Eric Rynes
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Hao Wang
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Shinny Vong
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Kristen Lee
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Daniel Bates
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Morgan Diegel
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Vaughn Roach
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Douglas Dunn
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Jun Neri
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Anthony Schafer
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - R. Scott Hansen
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA 98195
| | - Tanya Kutyavin
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Erika Giste
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Molly Weaver
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Theresa Canfield
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Peter Sabo
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Miaohua Zhang
- Basic Sciences Division, Fred Hutchison Cancer Research Center, Seattle, WA 98109
| | | | - Rachel Byron
- Basic Sciences Division, Fred Hutchison Cancer Research Center, Seattle, WA 98109
| | - Michael J. MacCoss
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Joshua M. Akey
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Michael Bender
- Basic Sciences Division, Fred Hutchison Cancer Research Center, Seattle, WA 98109
| | - Mark Groudine
- Basic Sciences Division, Fred Hutchison Cancer Research Center, Seattle, WA 98109
| | - Rajinder Kaul
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA 98195
| | - John A. Stamatoyannopoulos
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
- Division of Oncology, Deparment of Medicine, University of Washington, Seattle, WA 98195
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249
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Abstract
The human genome encodes the blueprint of life, but the function of the vast majority of its nearly three billion bases is unknown. The Encyclopedia of DNA Elements (ENCODE) project has systematically mapped regions of transcription, transcription factor association, chromatin structure and histone modification. These data enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions. Many discovered candidate regulatory elements are physically associated with one another and with expressed genes, providing new insights into the mechanisms of gene regulation. The newly identified elements also show a statistical correspondence to sequence variants linked to human disease, and can thereby guide interpretation of this variation. Overall, the project provides new insights into the organization and regulation of our genes and genome, and is an expansive resource of functional annotations for biomedical research.
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250
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Maurano MT, Humbert R, Rynes E, Thurman RE, Haugen E, Wang H, Reynolds AP, Sandstrom R, Qu H, Brody J, Shafer A, Neri F, Lee K, Kutyavin T, Stehling-Sun S, Johnson AK, Canfield TK, Giste E, Diegel M, Bates D, Hansen RS, Neph S, Sabo PJ, Heimfeld S, Raubitschek A, Ziegler S, Cotsapas C, Sotoodehnia N, Glass I, Sunyaev SR, Kaul R, Stamatoyannopoulos JA. Systematic localization of common disease-associated variation in regulatory DNA. Science 2012; 337:1190-5. [PMID: 22955828 DOI: 10.1126/science.1222794] [Citation(s) in RCA: 2490] [Impact Index Per Article: 207.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Genome-wide association studies have identified many noncoding variants associated with common diseases and traits. We show that these variants are concentrated in regulatory DNA marked by deoxyribonuclease I (DNase I) hypersensitive sites (DHSs). Eighty-eight percent of such DHSs are active during fetal development and are enriched in variants associated with gestational exposure-related phenotypes. We identified distant gene targets for hundreds of variant-containing DHSs that may explain phenotype associations. Disease-associated variants systematically perturb transcription factor recognition sequences, frequently alter allelic chromatin states, and form regulatory networks. We also demonstrated tissue-selective enrichment of more weakly disease-associated variants within DHSs and the de novo identification of pathogenic cell types for Crohn's disease, multiple sclerosis, and an electrocardiogram trait, without prior knowledge of physiological mechanisms. Our results suggest pervasive involvement of regulatory DNA variation in common human disease and provide pathogenic insights into diverse disorders.
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Affiliation(s)
- Matthew T Maurano
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
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