151
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Rahnamoun H, Lee J, Sun Z, Lu H, Ramsey KM, Komives EA, Lauberth SM. RNAs interact with BRD4 to promote enhanced chromatin engagement and transcription activation. Nat Struct Mol Biol 2018; 25:687-697. [PMID: 30076409 PMCID: PMC6859054 DOI: 10.1038/s41594-018-0102-0] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 06/20/2018] [Indexed: 12/31/2022]
Abstract
The bromodomain and extra-terminal motif (BET) protein BRD4 binds to acetylated histones at enhancers and promoters via its bromodomains (BDs) to regulate transcriptional elongation. In human colorectal cancer cells, we found that BRD4 was recruited to enhancers that were co-occupied by mutant p53 and supported the synthesis of enhancer-directed transcripts (eRNAs) in response to chronic immune signaling. BRD4 selectively associated with eRNAs that were produced from BRD4-bound enhancers. Using biochemical and biophysical methods, we found that BRD4 BDs function cooperatively as docking sites for eRNAs and that the BDs of BRD2, BRD3, BRDT, BRG1, and BRD7 directly interact with eRNAs. BRD4-eRNA interactions increased BRD4 binding to acetylated histones in vitro and augmented BRD4 enhancer recruitment and transcriptional cofactor activities. Our results suggest a mechanism by which eRNAs are directly involved in gene regulation by modulating enhancer interactions and transcriptional functions of BRD4.
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Affiliation(s)
- Homa Rahnamoun
- Section of Molecular Biology, University of California, San Diego, La Jolla, CA, USA
| | - Jihoon Lee
- Section of Molecular Biology, University of California, San Diego, La Jolla, CA, USA
| | - Zhengxi Sun
- Section of Molecular Biology, University of California, San Diego, La Jolla, CA, USA
| | - Hanbin Lu
- Section of Molecular Biology, University of California, San Diego, La Jolla, CA, USA
| | - Kristen M Ramsey
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Elizabeth A Komives
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Shannon M Lauberth
- Section of Molecular Biology, University of California, San Diego, La Jolla, CA, USA.
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152
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Temporal Viral Genome-Protein Interactions Define Distinct Stages of Productive Herpesviral Infection. mBio 2018; 9:mBio.01182-18. [PMID: 30018111 PMCID: PMC6050965 DOI: 10.1128/mbio.01182-18] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Herpesviruses utilize multiple mechanisms to redirect host proteins for use in viral processes and to avoid recognition and repression by the host. To investigate dynamic interactions between herpes simplex virus type 1 (HSV-1) DNA and viral and host proteins throughout infection, we developed an approach to identify proteins that associate with the infecting viral genome from nuclear entry through packaging. To accomplish this, virus stocks were prepared in the presence of ethynyl-modified nucleotides to enable covalent tagging of viral genomes after infection for analysis of viral genome-protein interactions by imaging or affinity purification. Affinity purification was combined with stable isotope labeling of amino acids in cell culture (SILAC) mass spectrometry to enable the distinction between proteins that were brought into the cell by the virus or expressed within the infected cell before or during infection. We found that input viral DNA progressed within 6 h through four temporal stages where the genomes sequentially (i) interacted with intrinsic antiviral and DNA damage response proteins, (ii) underwent a robust transcriptional switch mediated largely by ICP4, (iii) engaged in replication, repair, and continued transcription, and then (iv) transitioned to a more transcriptionally inert state engaging de novo-synthesized viral structural components while maintaining interactions with replication proteins. Using a combination of genetic, imaging, and proteomic approaches, we provide a new and temporally compressed view of the HSV-1 life cycle based on input genome-proteome dynamics. Herpesviruses are highly prevalent and ubiquitous human pathogens. Studies of herpesviruses and other viruses have previously been limited by the ability to directly study events that occur on the viral DNA throughout infection. We present a new powerful approach, which allows for the temporal investigation of viral genome-protein interactions at all phases of infection. This work has integrated many results from previous studies with the discovery of novel factors potentially involved in viral infection that may represent new antiviral targets. In addition, the study provides a new view of the HSV-1 life cycle based on genome-proteome dynamics.
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153
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Tsai PF, Dell'Orso S, Rodriguez J, Vivanco KO, Ko KD, Jiang K, Juan AH, Sarshad AA, Vian L, Tran M, Wangsa D, Wang AH, Perovanovic J, Anastasakis D, Ralston E, Ried T, Sun HW, Hafner M, Larson DR, Sartorelli V. A Muscle-Specific Enhancer RNA Mediates Cohesin Recruitment and Regulates Transcription In trans. Mol Cell 2018; 71:129-141.e8. [PMID: 29979962 PMCID: PMC6082425 DOI: 10.1016/j.molcel.2018.06.008] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/19/2018] [Accepted: 06/01/2018] [Indexed: 12/16/2022]
Abstract
The enhancer regions of the myogenic master regulator MyoD give rise to at least two enhancer RNAs. Core enhancer eRNA (CEeRNA) regulates transcription of the adjacent MyoD gene, whereas DRReRNA affects expression of Myogenin in trans. We found that DRReRNA is recruited at the Myogenin locus, where it colocalizes with Myogenin nascent transcripts. DRReRNA associates with the cohesin complex, and this association correlates with its transactivating properties. Despite being expressed in undifferentiated cells, cohesin is not loaded on Myogenin until the cells start expressing DRReRNA, which is then required for cohesin chromatin recruitment and maintenance. Functionally, depletion of either cohesin or DRReRNA reduces chromatin accessibility, prevents Myogenin activation, and hinders muscle cell differentiation. Thus, DRReRNA ensures spatially appropriate cohesin loading in trans to regulate gene expression.
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Affiliation(s)
- Pei-Fang Tsai
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Stefania Dell'Orso
- High-Throughput Sequencing Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Joseph Rodriguez
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Karinna O Vivanco
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Kyung-Dae Ko
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Kan Jiang
- Biodata Mining and Discovery Section, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Aster H Juan
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Aishe A Sarshad
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Laura Vian
- Translational Immunology Section, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Michelle Tran
- Light Imaging Section, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Darawalee Wangsa
- Genetics Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - A Hongjun Wang
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Jelena Perovanovic
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Dimitrios Anastasakis
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Evelyn Ralston
- Light Imaging Section, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Thomas Ried
- Genetics Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Hong-Wei Sun
- Biodata Mining and Discovery Section, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Markus Hafner
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA
| | - Daniel R Larson
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Vittorio Sartorelli
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), NIH, Bethesda, MD 20892, USA.
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154
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Birth, coming of age and death: The intriguing life of long noncoding RNAs. Semin Cell Dev Biol 2018; 79:143-152. [DOI: 10.1016/j.semcdb.2017.11.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Revised: 11/06/2017] [Accepted: 11/09/2017] [Indexed: 01/27/2023]
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155
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Barbieri E, Trizzino M, Welsh SA, Owens TA, Calabretta B, Carroll M, Sarma K, Gardini A. Targeted Enhancer Activation by a Subunit of the Integrator Complex. Mol Cell 2018; 71:103-116.e7. [PMID: 30008316 DOI: 10.1016/j.molcel.2018.05.031] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 04/11/2018] [Accepted: 05/24/2018] [Indexed: 01/12/2023]
Abstract
The control of cell fate is an epigenetic process initiated by transcription factors (TFs) that recognize DNA motifs and recruit activator complexes and transcriptional machineries to chromatin. Lineage specificity is thought to be provided solely by TF-motif pairing, while the recruited activators are passive. Here, we show that INTS13, a subunit of the Integrator complex, operates as monocytic/macrophagic differentiation factor. Integrator is a general activator of transcription at coding genes and is required for eRNA maturation. Here, we show that INTS13 functions as an independent sub-module and targets enhancers through Early Growth Response (EGR1/2) TFs and their co-factor NAB2. INTS13 binds poised monocytic enhancers eliciting chromatin looping and activation. Independent depletion of INTS13, EGR1, or NAB2 impairs monocytic differentiation of cell lines and primary human progenitors. Our data demonstrate that Integrator is not functionally homogeneous and has TF-specific regulatory potential, revealing a new enhancer regulatory axis that controls myeloid differentiation.
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Affiliation(s)
- Elisa Barbieri
- The Wistar Institute, Gene Expression and Regulation Program, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Marco Trizzino
- The Wistar Institute, Gene Expression and Regulation Program, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Sarah Ann Welsh
- The Wistar Institute, Gene Expression and Regulation Program, 3601 Spruce Street, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA
| | - Tori Alexandra Owens
- The Wistar Institute, Gene Expression and Regulation Program, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Bruno Calabretta
- Sidney Kimmel Cancer Center, Thomas Jefferson Medical School, Philadelphia, PA, USA
| | - Martin Carroll
- Division of Hematology and Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Kavitha Sarma
- The Wistar Institute, Gene Expression and Regulation Program, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Alessandro Gardini
- The Wistar Institute, Gene Expression and Regulation Program, 3601 Spruce Street, Philadelphia, PA 19104, USA.
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156
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Rickels R, Shilatifard A. Enhancer Logic and Mechanics in Development and Disease. Trends Cell Biol 2018; 28:608-630. [PMID: 29759817 DOI: 10.1016/j.tcb.2018.04.003] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 04/11/2018] [Accepted: 04/13/2018] [Indexed: 12/31/2022]
Abstract
Enhancers are distally located genomic cis-regulatory elements that integrate spatiotemporal cues to coordinate gene expression in a tissue-specific manner during metazoan development. Enhancer function depends on a combination of bound transcription factors and cofactors that regulate local chromatin structure, as well as on the topological interactions that are necessary for their activity. Numerous genome-wide studies concur that the vast majority of disease-associated variations occur within non-coding genomic sequences, in other words the 'cis-regulome', and this underscores their relevance for human health. Advances in DNA sequencing and genome-editing technologies have dramatically expanded our ability to identify enhancers and investigate their properties in vivo, revealing an extraordinary level of interconnectivity underlying cis-regulatory networks. We discuss here these recently developed methodologies, as well as emerging trends and remaining questions in the field of enhancer biology, and how perturbation of enhancer activities/functions results in enhanceropathies.
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Affiliation(s)
- Ryan Rickels
- Simpson Querrey Center for Epigenetics, and the Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, 320 East Superior Street, Chicago, IL 60611, USA
| | - Ali Shilatifard
- Simpson Querrey Center for Epigenetics, and the Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, 320 East Superior Street, Chicago, IL 60611, USA.
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157
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Irimie AI, Zimta AA, Ciocan C, Mehterov N, Dudea D, Braicu C, Berindan-Neagoe I. The Unforeseen Non-Coding RNAs in Head and Neck Cancer. Genes (Basel) 2018; 9:genes9030134. [PMID: 29494516 PMCID: PMC5867855 DOI: 10.3390/genes9030134] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/21/2018] [Accepted: 02/22/2018] [Indexed: 12/18/2022] Open
Abstract
Previously ignored non-coding RNAs (ncRNAs) have become the subject of many studies. However, there is an imbalance in the amount of consideration that ncRNAs are receiving. Some transcripts such as microRNAs (miRNAs) or small interfering RNAs (siRNAs) have gained much attention, but it is necessary to investigate other “pieces of the RNA puzzle”. These can offer a more complete view over normal and pathological cell behavior. The other ncRNA species are less studied, either due to their recent discovery, such as stable intronic sequence RNA (sisRNA), YRNA, miRNA-offset RNAs (moRNA), telomerase RNA component (TERC), natural antisense transcript (NAT), transcribed ultraconserved regions (T-UCR), and pseudogene transcript, or because they are still largely seen as non-coding transcripts with no relevance to pathogenesis. Moreover, some are still considered housekeeping RNAs, for instance small nucleolar RNAs (snoRNAs) and TERC. Our review summarizes the biogenesis, mechanism of action and potential role of less known ncRNAs in head and neck cancer, with a particular focus on the installment and progress for this particular cancer type.
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Affiliation(s)
- Alexandra Iulia Irimie
- Department of Prosthetic Dentistry and Dental Materials, Division Dental Propaedeutic, Aesthetic, "IuliuHatieganu" University of Medicine and Pharmacy, Cluj-Napoca, 23 Marinescu Street, 40015 Cluj-Napoca, Romania.
| | - Alina-Andreea Zimta
- MEDFUTURE-Research Center for Advanced Medicine, University of Medicine and Pharmacy Iuliu-Hatieganu, 23 Marinescu Street, 40015 Cluj-Napoca, Romania.
| | - Cristina Ciocan
- MEDFUTURE-Research Center for Advanced Medicine, University of Medicine and Pharmacy Iuliu-Hatieganu, 23 Marinescu Street, 40015 Cluj-Napoca, Romania.
| | - Nikolay Mehterov
- Department of Medical Biology, Medical University Plovdiv, BulVasilAprilov 15-А, Plovdiv 4002, Bulgaria.
- Technological Center for Emergency Medicine, BulVasilAprilov 15-А, Plovdiv 4002, Bulgaria.
| | - Diana Dudea
- Department of Prosthetic Dentistry and Dental Materials, Division Dental Propaedeutic, Aesthetic, "IuliuHatieganu" University of Medicine and Pharmacy, Cluj-Napoca, 23 Marinescu Street, 40015 Cluj-Napoca, Romania.
| | - Cornelia Braicu
- Research Center for Functional Genomics and Translational Medicine, "IuliuHatieganu" University of Medicine and Pharmacy, 23 Marinescu Street, 40015 Cluj-Napoca, Romania.
| | - Ioana Berindan-Neagoe
- MEDFUTURE-Research Center for Advanced Medicine, University of Medicine and Pharmacy Iuliu-Hatieganu, 23 Marinescu Street, 40015 Cluj-Napoca, Romania.
- Research Center for Functional Genomics and Translational Medicine, "IuliuHatieganu" University of Medicine and Pharmacy, 23 Marinescu Street, 40015 Cluj-Napoca, Romania.
- Department of Functional Genomics and Experimental Pathology, The Oncology Institute "Prof. Dr. Ion Chiricuta", Republicii 34 Street, 400015 Cluj-Napoca, Romania.
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158
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Goh KY, Inoue T. A large transcribed enhancer region regulates C. elegans bed-3 and the development of egg laying muscles. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:519-533. [PMID: 29481869 DOI: 10.1016/j.bbagrm.2018.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/21/2018] [Accepted: 02/21/2018] [Indexed: 01/05/2023]
Abstract
Gene expression is regulated by the interaction of the RNA polymerase with various transcription factors at promoter and enhancer elements. Transcriptome analyses found that many non-protein-coding regions are transcribed to produce long non-coding RNAs and enhancer-associated RNAs. Production of these transcripts is associated with activation of nearby protein-coding genes, and at least in some cases, the transcripts themselves mediate this activation. Non-coding transcripts are also reported from large enhancers or clusters of enhancers. However, not much is known about the function of large transcribed enhancer regions during organismal development. Here we investigated a transcribed 10.6 kb intergenic region located upstream of the C. elegans bed-3 gene. We found that parts of this region exhibit tissue-specific promoter and enhancer activities. Deletion of the region disrupts egg laying, a phenotype also observed in bed-3 mutants, but with the severity correlating with the size of the deletion. This phenotype is not caused by overall reduction in bed-3 expression. Rather, deletions reduce bed-3 expression specifically in the mesoderm lineage. We found that bed-3 has a previously unknown function in the generation of sex myoblast (SM) cells from the M lineage, and deletions cause loss of SM cells leading to loss of vulval muscles required for egg laying. Furthermore, injection of dsRNA targeting non-coding transcripts from this region disrupted egg laying in the wild type but not in RNAi-defective mutants. Therefore, the region upstream of bed-3 is required for robust expression of bed-3 in a specific tissue, and non-coding transcripts may mediate this interaction.
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Affiliation(s)
- Kah Yee Goh
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597
| | - Takao Inoue
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597.
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159
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Capturing the interactome of newly transcribed RNA. Nat Methods 2018; 15:213-220. [PMID: 29431736 DOI: 10.1038/nmeth.4595] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 12/11/2017] [Indexed: 12/18/2022]
Abstract
We combine the labeling of newly transcribed RNAs with 5-ethynyluridine with the characterization of bound proteins. This approach, named capture of the newly transcribed RNA interactome using click chemistry (RICK), systematically captures proteins bound to a wide range of RNAs, including nascent RNAs and traditionally neglected nonpolyadenylated RNAs. RICK has identified mitotic regulators amongst other novel RNA-binding proteins with preferential affinity for nonpolyadenylated RNAs, revealed a link between metabolic enzymes/factors and nascent RNAs, and expanded the known RNA-bound proteome of mouse embryonic stem cells. RICK will facilitate an in-depth interrogation of the total RNA-bound proteome in different cells and systems.
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160
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Chiu AC, Suzuki HI, Wu X, Mahat DB, Kriz AJ, Sharp PA. Transcriptional Pause Sites Delineate Stable Nucleosome-Associated Premature Polyadenylation Suppressed by U1 snRNP. Mol Cell 2018; 69:648-663.e7. [PMID: 29398447 DOI: 10.1016/j.molcel.2018.01.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/21/2017] [Accepted: 01/04/2018] [Indexed: 12/16/2022]
Abstract
Regulation of RNA polymerase II (Pol II) elongation is a critical step in gene regulation. Here, we report that U1 snRNP recognition and transcription pausing at stable nucleosomes are linked through premature polyadenylation signal (PAS) termination. By generating RNA exosome conditional deletion mouse embryonic stem cells, we identified a large class of polyadenylated short transcripts in the sense direction destabilized by the RNA exosome. These PAS termination events are enriched at the first few stable nucleosomes flanking CpG islands and suppressed by U1 snRNP. Thus, promoter-proximal Pol II pausing consists of two processes: TSS-proximal and +1 stable nucleosome pausing, with PAS termination coinciding with the latter. While pausing factors NELF/DSIF only function in the former step, flavopiridol-sensitive mechanism(s) and Myc modulate both steps. We propose that premature PAS termination near the nucleosome-associated pause site represents a common transcriptional elongation checkpoint regulated by U1 snRNP recognition, nucleosome stability, and Myc activity.
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Affiliation(s)
- Anthony C Chiu
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Hiroshi I Suzuki
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Xuebing Wu
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Dig B Mahat
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Andrea J Kriz
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Phillip A Sharp
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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161
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Catarino RR, Stark A. Assessing sufficiency and necessity of enhancer activities for gene expression and the mechanisms of transcription activation. Genes Dev 2018; 32:202-223. [PMID: 29491135 PMCID: PMC5859963 DOI: 10.1101/gad.310367.117] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Enhancers are important genomic regulatory elements directing cell type-specific transcription. They assume a key role during development and disease, and their identification and functional characterization have long been the focus of scientific interest. The advent of next-generation sequencing and clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9-based genome editing has revolutionized the means by which we study enhancer biology. In this review, we cover recent developments in the prediction of enhancers based on chromatin characteristics and their identification by functional reporter assays and endogenous DNA perturbations. We discuss that the two latter approaches provide different and complementary insights, especially in assessing enhancer sufficiency and necessity for transcription activation. Furthermore, we discuss recent insights into mechanistic aspects of enhancer function, including findings about cofactor requirements and the role of post-translational histone modifications such as monomethylation of histone H3 Lys4 (H3K4me1). Finally, we survey how these approaches advance our understanding of transcription regulation with respect to promoter specificity and transcriptional bursting and provide an outlook covering open questions and promising developments.
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Affiliation(s)
- Rui R Catarino
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Alexander Stark
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
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162
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Scruggs BS, Adelman K. The Importance of Controlling Transcription Elongation at Coding and Noncoding RNA Loci. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2018; 80:33-44. [PMID: 27325707 DOI: 10.1101/sqb.2015.80.027235] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Here we discuss current paradigms for how transcription initiation and elongation control are achieved in mammalian cells, and how they differ at protein-coding mRNA genes versus noncoding RNA (ncRNA) loci. We present a model for the function of ncRNAs wherein the act of transcription is regulatory, rather than the ncRNA products themselves. We further describe how the establishment of transcriptionally engaged, but paused, RNA polymerase II impacts chromatin structure around divergent transcription start sites, and how this can influence transcription factor binding and mRNA gene activity in the region.
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Affiliation(s)
- Benjamin S Scruggs
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Karen Adelman
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
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163
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Nilson KA, Lawson CK, Mullen NJ, Ball CB, Spector BM, Meier JL, Price DH. Oxidative stress rapidly stabilizes promoter-proximal paused Pol II across the human genome. Nucleic Acids Res 2017; 45:11088-11105. [PMID: 28977633 PMCID: PMC5737879 DOI: 10.1093/nar/gkx724] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/08/2017] [Indexed: 12/29/2022] Open
Abstract
Oxidative stress has pervasive effects on cells but how they respond transcriptionally upon the initial insult is incompletely understood. We developed a nuclear walk-on assay that semi-globally quantifies nascent transcripts in promoter-proximal paused RNA polymerase II (Pol II). Using this assay in conjunction with ChIP-Seq, in vitro transcription, and a chromatin retention assay, we show that within a minute, hydrogen peroxide causes accumulation of Pol II near promoters and enhancers that can best be explained by a rapid decrease in termination. Some of the accumulated polymerases slowly move or ‘creep’ downstream. This second effect is correlated with and probably results from loss of NELF association and function. Notably, both effects were independent of DNA damage and ADP-ribosylation. Our results demonstrate the unexpected speed at which a global transcriptional response can occur. The findings provide strong support for the residence time of paused Pol II elongation complexes being much shorter than estimated from previous studies.
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Affiliation(s)
- Kyle A Nilson
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA.,Molecular and Cellular Biology Program, University of Iowa, Iowa City, IA 52242, USA
| | - Christine K Lawson
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Nicholas J Mullen
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Christopher B Ball
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Benjamin M Spector
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Jeffery L Meier
- Department of Internal Medicine, University of Iowa and Veterans Affairs Health Care System, Iowa City, IA 52242, USA
| | - David H Price
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA.,Molecular and Cellular Biology Program, University of Iowa, Iowa City, IA 52242, USA
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164
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Meng H, Bartholomew B. Emerging roles of transcriptional enhancers in chromatin looping and promoter-proximal pausing of RNA polymerase II. J Biol Chem 2017; 293:13786-13794. [PMID: 29187597 DOI: 10.1074/jbc.r117.813485] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Initiation and regulation of transcription by RNA polymerase II (RNAPII) in eukaryotes rely on the transcriptional regulatory elements. Promoters and enhancers share similar architectures and functions, and the prevailing view is that they can initiate bidirectional transcription. We summarize functional roles of enhancer transcription and possible mechanisms in enhancer-promoter communication. We discuss the potential roles of enhancer RNAs (eRNAs) in early elongation and highlight that transcriptional enhancers might modulate the release of paused RNAPII via 3D chromatin looping. Emerging evidence suggests that transcriptional enhancers regulate the promoter-proximal pausing of RNAPII, a key rate-limiting step required for productive elongation.
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Affiliation(s)
- Huan Meng
- From the Department of Epigenetics and Molecular Carcinogenesis, the University of Texas MD Anderson Cancer Center, Smithville, Texas 78957
| | - Blaine Bartholomew
- From the Department of Epigenetics and Molecular Carcinogenesis, the University of Texas MD Anderson Cancer Center, Smithville, Texas 78957
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165
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Iasillo C, Schmid M, Yahia Y, Maqbool MA, Descostes N, Karadoulama E, Bertrand E, Andrau JC, Jensen TH. ARS2 is a general suppressor of pervasive transcription. Nucleic Acids Res 2017; 45:10229-10241. [PMID: 28973446 PMCID: PMC5622339 DOI: 10.1093/nar/gkx647] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 07/18/2017] [Indexed: 01/06/2023] Open
Abstract
Termination of transcription is important for establishing gene punctuation marks. It is also critical for suppressing many of the pervasive transcription events occurring throughout eukaryotic genomes and coupling their RNA products to efficient decay. In human cells, the ARS2 protein has been implicated in such function as its depletion causes transcriptional read-through of selected gene terminators and because it physically interacts with the ribonucleolytic nuclear RNA exosome. Here, we study the role of ARS2 on transcription and RNA metabolism genome wide. We show that ARS2 depletion negatively impacts levels of promoter-proximal RNA polymerase II at protein-coding (pc) genes. Moreover, our results reveal a general role of ARS2 in transcription termination-coupled RNA turnover at short transcription units like snRNA-, replication-dependent histone-, promoter upstream transcript- and enhancer RNA-loci. Depletion of the ARS2 interaction partner ZC3H18 mimics the ARS2 depletion, although to a milder extent, whereas depletion of the exosome core subunit RRP40 only impacts RNA abundance post-transcriptionally. Interestingly, ARS2 is also involved in transcription termination events within first introns of pc genes. Our work therefore establishes ARS2 as a general suppressor of pervasive transcription with the potential to regulate pc gene expression.
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Affiliation(s)
- Claudia Iasillo
- Department of Molecular Biology and Genetics, Aarhus University, C. F. M⊘llers Allé 3, Building 1130, DK-8000 Aarhus C, Denmark.,IGMM, CNRS, Univ. Montpellier, 34293 Montpellier, Cedex 5, France
| | - Manfred Schmid
- Department of Molecular Biology and Genetics, Aarhus University, C. F. M?llers Allé 3, Building 1130, DK-8000 Aarhus C, Denmark
| | - Yousra Yahia
- IGMM, CNRS, Univ. Montpellier, 34293 Montpellier, Cedex 5, France
| | | | - Nicolas Descostes
- IGMM, CNRS, Univ. Montpellier, 34293 Montpellier, Cedex 5, France.,Howard Hughes Medical Institute, New York, NY 10016, USA.,Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Evdoxia Karadoulama
- Department of Molecular Biology and Genetics, Aarhus University, C. F. M?llers Allé 3, Building 1130, DK-8000 Aarhus C, Denmark
| | - Edouard Bertrand
- IGMM, CNRS, Univ. Montpellier, 34293 Montpellier, Cedex 5, France
| | | | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. M?llers Allé 3, Building 1130, DK-8000 Aarhus C, Denmark
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166
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Yue J, Lai F, Beckedorff F, Zhang A, Pastori C, Shiekhattar R. Integrator orchestrates RAS/ERK1/2 signaling transcriptional programs. Genes Dev 2017; 31:1809-1820. [PMID: 28982763 PMCID: PMC5666678 DOI: 10.1101/gad.301697.117] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/01/2017] [Indexed: 01/02/2023]
Abstract
In this study, Yue et al. describe a new role for the RNAPII-associated complex Integrator in MAPK signaling. They show that Integrator mediates the transcriptional responsiveness following growth factor signaling, that depletion of Integrator can suppress MAPK signaling to the nucleus, and that Integrator could be targeted in MAPK-driven cancers that are resistant to conventional inhibitors of the MAPK pathway. Activating mutations in the mitogen-activated protein kinase (MAPK) cascade, also known as the RAS–MEK–extracellular signal-related kinase (ERK1/2) pathway, are an underlying cause of >70% of human cancers. While great strides have been made toward elucidating the cytoplasmic components of MAPK signaling, the key downstream coactivators that coordinate the transcriptional response have not been fully illustrated. Here, we demonstrate that the MAPK transcriptional response in human cells is funneled through Integrator, an RNA polymerase II-associated complex. Integrator depletion diminishes ERK1/2 transcriptional responsiveness and cellular growth in human cancers harboring activating mutations in MAPK signaling. Pharmacological inhibition of the MAPK pathway abrogates the stimulus-dependent recruitment of Integrator at immediate early genes and their enhancers. Following epidermal growth factor (EGF) stimulation, activated ERK1/2 is recruited to immediate early genes and phosphorylates INTS11, the catalytic subunit of Integrator. Importantly, in contrast to the broad effects of Integrator knockdown on MAPK responsiveness, depletion of a number of critical subunits of the coactivator complex Mediator alters only a few MAPK-responsive genes. Finally, human cancers with activating mutations in the MAPK cascade, rendered resistant to targeted therapies, display diminished growth following depletion of Integrator. We propose Integrator as a crucial transcriptional coactivator in MAPK signaling, which could serve as a downstream therapeutic target for cancer treatment.
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Affiliation(s)
- Jingyin Yue
- Department of Human Genetics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
| | - Fan Lai
- Department of Human Genetics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
| | - Felipe Beckedorff
- Department of Human Genetics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
| | - Anda Zhang
- Department of Human Genetics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
| | - Chiara Pastori
- Department of Neurological Surgery, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
| | - Ramin Shiekhattar
- Department of Human Genetics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
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167
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Armour SM, Remsberg JR, Damle M, Sidoli S, Ho WY, Li Z, Garcia BA, Lazar MA. An HDAC3-PROX1 corepressor module acts on HNF4α to control hepatic triglycerides. Nat Commun 2017; 8:549. [PMID: 28916805 PMCID: PMC5601916 DOI: 10.1038/s41467-017-00772-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 07/26/2017] [Indexed: 01/23/2023] Open
Abstract
The histone deacetylase HDAC3 is a critical mediator of hepatic lipid metabolism, and liver-specific deletion of HDAC3 leads to fatty liver. To elucidate the underlying mechanism, here we report a method of cross-linking followed by mass spectrometry to define a high-confidence HDAC3 interactome in vivo that includes the canonical NCoR-HDAC3 complex as well as Prospero-related homeobox 1 protein (PROX1). HDAC3 and PROX1 co-localize extensively on the mouse liver genome, and are co-recruited by hepatocyte nuclear factor 4α (HNF4α). The HDAC3-PROX1 module controls the expression of a gene program regulating lipid homeostasis, and hepatic-specific ablation of either component increases triglyceride content in liver. These findings underscore the importance of specific combinations of transcription factors and coregulators in the fine tuning of organismal metabolism.HDAC3 is a critical mediator of hepatic lipid metabolism and its loss leads to fatty liver. Here, the authors characterize the liver HDAC3 interactome in vivo, provide evidence that HDAC3 interacts with PROX1, and show that HDAC3 and PROX1 control expression of genes regulating lipid homeostasis.
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Affiliation(s)
- Sean M Armour
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA.,Divison of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA
| | - Jarrett R Remsberg
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA.,Divison of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA.,Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA
| | - Manashree Damle
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA.,Divison of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA
| | - Simone Sidoli
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA
| | - Wesley Y Ho
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA.,Divison of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA
| | - Zhenghui Li
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA.,Divison of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA. .,Divison of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, SCTR 12-102, Philadelphia, PA, 19104, USA.
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168
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Fok ET, Scholefield J, Fanucchi S, Mhlanga MM. The emerging molecular biology toolbox for the study of long noncoding RNA biology. Epigenomics 2017; 9:1317-1327. [PMID: 28875715 DOI: 10.2217/epi-2017-0062] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Long noncoding RNAs (lncRNAs) have been implicated in many biological processes. However, due to the unique nature of lncRNAs and the consequential difficulties associated with their characterization, there is a growing disparity between the rate at which lncRNAs are being discovered and the assignment of biological function to these transcripts. Here we present a molecular biology toolbox equipped to help dissect aspects of lncRNA biology and reveal functionality. We outline an approach that begins with a broad survey of genome-wide, high-throughput datasets to identify potential lncRNA candidates and then narrow the focus on specific methods that are well suited to interrogate the transcripts of interest more closely. This involves the use of imaging-based strategies to validate these candidates and observe the behaviors of these transcripts at single molecule resolution in individual cells. We also describe the use of gene editing tools and interactome capture techniques to interrogate functionality and infer mechanism, respectively. With the emergence of lncRNAs as important molecules in healthy and diseased cellular function, it remains crucial to deepen our understanding of their biology.
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Affiliation(s)
- Ezio T Fok
- Gene Expression & Biophysics Group, Biosciences, CSIR, Pretoria, Gauteng, South Africa.,Division of Chemical, Systems & Synthetic Biology, Institute for Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Janine Scholefield
- Gene Expression & Biophysics Group, Biosciences, CSIR, Pretoria, Gauteng, South Africa.,Division of Chemical, Systems & Synthetic Biology, Institute for Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Stephanie Fanucchi
- Gene Expression & Biophysics Group, Biosciences, CSIR, Pretoria, Gauteng, South Africa.,Division of Chemical, Systems & Synthetic Biology, Institute for Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Musa M Mhlanga
- Gene Expression & Biophysics Group, Biosciences, CSIR, Pretoria, Gauteng, South Africa.,Division of Chemical, Systems & Synthetic Biology, Institute for Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape, South Africa.,Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, Lisbon, Portugal
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169
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Abstract
Macrophages play essential roles in the response to injury and infection and contribute to the development and/or homeostasis of the various tissues they reside in. Conversely, macrophages also influence the pathogenesis of metabolic, neurodegenerative, and neoplastic diseases. Mechanisms that contribute to the phenotypic diversity of macrophages in health and disease remain poorly understood. Here we review the recent application of genome-wide approaches to characterize the transcriptomes and epigenetic landscapes of tissue-resident macrophages. These studies are beginning to provide insights into how distinct tissue environments are interpreted by transcriptional regulatory elements to drive specialized programs of gene expression.
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170
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Atlasi Y, Stunnenberg HG. The interplay of epigenetic marks during stem cell differentiation and development. Nat Rev Genet 2017; 18:643-658. [PMID: 28804139 DOI: 10.1038/nrg.2017.57] [Citation(s) in RCA: 293] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Chromatin, the template for epigenetic regulation, is a highly dynamic entity that is constantly reshaped during early development and differentiation. Epigenetic modification of chromatin provides the necessary plasticity for cells to respond to environmental and positional cues, and enables the maintenance of acquired information without changing the DNA sequence. The mechanisms involve, among others, chemical modifications of chromatin, changes in chromatin constituents and reconfiguration of chromatin interactions and 3D structure. New advances in genome-wide technologies have paved the way towards an integrative view of epigenome dynamics during cell state transitions, and recent findings in embryonic stem cells highlight how the interplay between different epigenetic layers reshapes the transcriptional landscape.
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Affiliation(s)
- Yaser Atlasi
- Department of Molecular Biology, Faculty of Science, Radboud University, 6525 GA Nijmegen, The Netherlands
| | - Hendrik G Stunnenberg
- Department of Molecular Biology, Faculty of Science, Radboud University, 6525 GA Nijmegen, The Netherlands
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171
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Rahman S, Zorca CE, Traboulsi T, Noutahi E, Krause MR, Mader S, Zenklusen D. Single-cell profiling reveals that eRNA accumulation at enhancer-promoter loops is not required to sustain transcription. Nucleic Acids Res 2017; 45:3017-3030. [PMID: 27932455 PMCID: PMC5389544 DOI: 10.1093/nar/gkw1220] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 11/23/2016] [Indexed: 02/06/2023] Open
Abstract
Enhancers are intergenic DNA elements that regulate the transcription of target genes in response to signaling pathways by interacting with promoters over large genomic distances. Recent studies have revealed that enhancers are bi-directionally transcribed into enhancer RNAs (eRNAs). Using single-molecule fluorescence in situ hybridization (smFISH), we investigated the eRNA-mediated regulation of transcription during estrogen induction in MCF-7 cells. We demonstrate that eRNAs are localized exclusively in the nucleus and are induced with similar kinetics as target mRNAs. However, eRNAs are mostly nascent at enhancers and their steady-state levels remain lower than those of their cognate mRNAs. Surprisingly, at the single-allele level, eRNAs are rarely co-expressed with their target loci, demonstrating that active gene transcription does not require the continuous transcription of eRNAs or their accumulation at enhancers. When co-expressed, sub-diffraction distance measurements between nascent mRNA and eRNA signals reveal that co-transcription of eRNAs and mRNAs rarely occurs within closed enhancer–promoter loops. Lastly, basal eRNA transcription at enhancers, but not E2-induced transcription, is maintained upon depletion of MLL1 and ERα, suggesting some degree of chromatin accessibility prior to signal-dependent activation of transcription. Together, our findings suggest that eRNA accumulation at enhancer–promoter loops is not required to sustain target gene transcription.
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Affiliation(s)
- Samir Rahman
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Cornelia E Zorca
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Tatiana Traboulsi
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC H3T 1J4, Canada.,Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Emmanuel Noutahi
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Matthew R Krause
- Montreal Neurological Institute, McGill University, Montréal, QC H3A 2B4, Canada
| | - Sylvie Mader
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC H3T 1J4, Canada.,Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Daniel Zenklusen
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC H3T 1J4, Canada
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172
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Chromatin-enriched lncRNAs can act as cell-type specific activators of proximal gene transcription. Nat Struct Mol Biol 2017. [PMID: 28628087 PMCID: PMC5682930 DOI: 10.1038/nsmb.3424] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We recently described a new class of long noncoding RNA defined by especially tight chromatin association, whose presence is strongly correlated with expression of nearby genes in HEK293 cells. Here we critically examine the generality and cis-enhancer mechanism of this class of chromatin enriched RNA (cheRNA). CheRNA are largely cell-type specific, and remain the most effective chromatin signature for predicting cis-gene transcription in all cell types examined. Targeted depletion of three cheRNAs decreases gene expression of their neighbors, indicating potential co-activator function. Single-molecule FISH of one cheRNA-distal target gene pair suggests spatial overlap consistent with a role in chromosome looping. In another example, the cheRNA HIDALGO stimulates the fetal hemoglobin HBG1 gene during erythroid differentiation by promoting contacts to a downstream enhancer. Our results suggest that many cheRNAs activate proximal, lineage-specific gene transcription.
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173
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Abstract
Long noncoding RNAs (lncRNAs) are emerging as potential key regulators in gene expression networks and exhibit a surprising range of shapes and sizes. Several distinct classes of lncRNAs are transcribed from different DNA elements, including promoters, enhancers, and intergenic regions in eukaryotic genomes. Additionally, others are derived from long primary transcripts with noncanonical RNA processing pathways, generating new RNA species with unexpected formats. These lncRNAs can be processed by several mechanisms, including ribonuclease P (RNase P) cleavage to generate mature 3' ends, capping by small nucleolar RNA (snoRNA)-protein (snoRNP) complexes at their ends, or the formation of circular structures. Here we review current knowledge on lncRNAs and highlight the most recent discoveries of the underlying mechanisms related to their formation.
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Affiliation(s)
- Huang Wu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Li Yang
- Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China; School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai 201210, China.
| | - Ling-Ling Chen
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China; School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai 201210, China.
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174
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Shii L, Song L, Maurer K, Zhang Z, Sullivan KE. SERPINB2 is regulated by dynamic interactions with pause-release proteins and enhancer RNAs. Mol Immunol 2017; 88:20-31. [PMID: 28578223 DOI: 10.1016/j.molimm.2017.05.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/03/2017] [Accepted: 05/04/2017] [Indexed: 01/08/2023]
Abstract
The SERPINB2 gene is strongly upregulated in inflammatory states. In monocytes, it can constitute up to 1% of total cellular protein. It functions in protection from proteotoxic stress and plays a role in angioedema. The purpose of this study was to define the roles of enhancer RNAs embedded in the SERPIN gene complex. We found that the upstream enhancer RNAs upregulated SERPINB2 and the enhancer RNAs were expressed prior to those of SERPINB2 mRNA. Studies of the SERPINB2 promoter demonstrated the presence of an RNA polymerase II pause-inducing protein, NELF. Stimulation with LPS led to recruitment of the pause-releasing kinase P-TEFb and departure of the pause-inducing protein NELF. RNA immunoprecipitation revealed that NELF and the CDK9 component of P-TEFb bound to the enhancer RNAs after stimulation with distinct kinetics. Knock-down of the enhancer RNAs compromised stimulus induction of promoter and enhancer chromatin changes. Conversely, over-expression was associated with enhanced recruitment of c-JUN and increased expression of SERPINB2 mRNA expression. This study is the first to associate enhancer RNAs with SERPINB2 and is the first demonstration of acquisition of NELF binding by enhancer RNAs on chromatin.
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Affiliation(s)
- Lihua Shii
- The Division of Allergy Immunology at The Children's Hospital of Philadelphia, 3615 Civic Center Blvd., Philadelphia, PA 19104, USA.
| | - Li Song
- The Division of Allergy Immunology at The Children's Hospital of Philadelphia, 3615 Civic Center Blvd., Philadelphia, PA 19104, USA.
| | - Kelly Maurer
- The Division of Allergy Immunology at The Children's Hospital of Philadelphia, 3615 Civic Center Blvd., Philadelphia, PA 19104, USA.
| | - Zhe Zhang
- The Department of Biomedical and Health informatics at the Children's Hospital of Philadelphia, 3535 Market St., Philadelphia, PA 19104, USA.
| | - Kathleen E Sullivan
- The Division of Allergy Immunology at The Children's Hospital of Philadelphia, 3615 Civic Center Blvd., Philadelphia, PA 19104, USA.
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175
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Oegema R, Baillat D, Schot R, van Unen LM, Brooks A, Kia SK, Hoogeboom AJM, Xia Z, Li W, Cesaroni M, Lequin MH, van Slegtenhorst M, Dobyns WB, de Coo IFM, Verheijen FW, Kremer A, van der Spek PJ, Heijsman D, Wagner EJ, Fornerod M, Mancini GMS. Human mutations in integrator complex subunits link transcriptome integrity to brain development. PLoS Genet 2017; 13:e1006809. [PMID: 28542170 PMCID: PMC5466333 DOI: 10.1371/journal.pgen.1006809] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 06/09/2017] [Accepted: 05/09/2017] [Indexed: 02/06/2023] Open
Abstract
Integrator is an RNA polymerase II (RNAPII)-associated complex that was recently identified to have a broad role in both RNA processing and transcription regulation. Importantly, its role in human development and disease is so far largely unexplored. Here, we provide evidence that biallelic Integrator Complex Subunit 1 (INTS1) and Subunit 8 (INTS8) gene mutations are associated with rare recessive human neurodevelopmental syndromes. Three unrelated individuals of Dutch ancestry showed the same homozygous truncating INTS1 mutation. Three siblings harboured compound heterozygous INTS8 mutations. Shared features by these six individuals are severe neurodevelopmental delay and a distinctive appearance. The INTS8 family in addition presented with neuronal migration defects (periventricular nodular heterotopia). We show that the first INTS8 mutation, a nine base-pair deletion, leads to a protein that disrupts INT complex stability, while the second missense mutation introduces an alternative splice site leading to an unstable messenger. Cells from patients with INTS8 mutations show increased levels of unprocessed UsnRNA, compatible with the INT function in the 3’-end maturation of UsnRNA, and display significant disruptions in gene expression and RNA processing. Finally, the introduction of the INTS8 deletion mutation in P19 cells using genome editing alters gene expression throughout the course of retinoic acid-induced neural differentiation. Altogether, our results confirm the essential role of Integrator to transcriptome integrity and point to the requirement of the Integrator complex in human brain development. Neurodevelopmental disorders often have a genetic cause, however the genes and the underlying mechanisms that are involved are increasingly diverse, pointing to the complexity of brain development. For normal cell function and in general for normal development, mechanisms that regulate gene transcription into mRNA are of outermost importance as proper spatial and temporal expression of key developmentally regulated transcripts is essential. The Integrator complex was recently identified to have a broad role in both RNA processing and transcription regulation. This complex is assembled from at least 14 different subunits and several animal studies have pointed to an important role in development. Nevertheless, studies directly demonstrating the relevance of this complex in human health and development have been lacking until now. We show here that mutations in the Integrator Complex Subunit 1 gene (INTS1) and Subunit 8 gene (INTS8) cause a severe neurodevelopmental syndrome, characterized by profound intellectual disability, epilepsy, spasticity, facial and limb dysmorphism and subtle structural brain abnormalities. While the role of the Integrator complex in neuronal migration has recently been established, we provide evidence that INTS8 mutations lead in vitro to instability of the complex and impaired function. In patients cultured fibroblasts we found evidence for abnormalities in mRNA transcription and processing. In addition, introduction of INTS8 mutations in an in vitro model of retinoic acid-induced neuronal differentiation results also in transcription alterations. Altogether our results suggest an evolutionary conserved requirement of INTS1 and INTS8 in brain development.
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Affiliation(s)
- Renske Oegema
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - David Baillat
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston TX, United States of America
| | - Rachel Schot
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Leontine M. van Unen
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Alice Brooks
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Sima Kheradmand Kia
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | | | - Zheng Xia
- Division of Biostatistics, Dan L Duncan Cancer Center, Baylor College of Medicine, Houston, TX, United States of America
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States of America
| | - Wei Li
- Division of Biostatistics, Dan L Duncan Cancer Center, Baylor College of Medicine, Houston, TX, United States of America
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States of America
| | - Matteo Cesaroni
- The Fels Institute, Temple University School of Medicine, Philadelphia, PA, United States of America
| | - Maarten H. Lequin
- Department of Pediatric Radiology, Erasmus MC- Sophia, University Medical Center Rotterdam, The Netherlands
| | - Marjon van Slegtenhorst
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - William B. Dobyns
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Irenaeus F. M. de Coo
- Department of Neurology, Erasmus MC- Sophia, University Medical Center Rotterdam, The Netherlands
| | - Frans W. Verheijen
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Andreas Kremer
- Department of Bioinformatics, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Peter J. van der Spek
- Department of Bioinformatics, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Daphne Heijsman
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Department of Bioinformatics, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Eric J. Wagner
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston TX, United States of America
- * E-mail: (GMSM); (EJW)
| | - Maarten Fornerod
- Department of Pediatric Oncology and Biochemistry, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Grazia M. S. Mancini
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- * E-mail: (GMSM); (EJW)
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176
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Pan-Cancer Mutational and Transcriptional Analysis of the Integrator Complex. Int J Mol Sci 2017; 18:ijms18050936. [PMID: 28468258 PMCID: PMC5454849 DOI: 10.3390/ijms18050936] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 04/20/2017] [Accepted: 04/23/2017] [Indexed: 12/28/2022] Open
Abstract
The integrator complex has been recently identified as a key regulator of RNA Polymerase II-mediated transcription, with many functions including the processing of small nuclear RNAs, the pause-release and elongation of polymerase during the transcription of protein coding genes, and the biogenesis of enhancer derived transcripts. Moreover, some of its components also play a role in genome maintenance. Thus, it is reasonable to hypothesize that their functional impairment or altered expression can contribute to malignancies. Indeed, several studies have described the mutations or transcriptional alteration of some Integrator genes in different cancers. Here, to draw a comprehensive pan-cancer picture of the genomic and transcriptomic alterations for the members of the complex, we reanalyzed public data from The Cancer Genome Atlas. Somatic mutations affecting Integrator subunit genes and their transcriptional profiles have been investigated in about 11,000 patients and 31 tumor types. A general heterogeneity in the mutation frequencies was observed, mostly depending on tumor type. Despite the fact that we could not establish them as cancer drivers, INTS7 and INTS8 genes were highly mutated in specific cancers. A transcriptome analysis of paired (normal and tumor) samples revealed that the transcription of INTS7, INTS8, and INTS13 is significantly altered in several cancers. Experimental validation performed on primary tumors confirmed these findings.
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177
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Enhancers and chromatin structures: regulatory hubs in gene expression and diseases. Biosci Rep 2017; 37:BSR20160183. [PMID: 28351896 PMCID: PMC5408663 DOI: 10.1042/bsr20160183] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/23/2017] [Accepted: 03/27/2017] [Indexed: 12/14/2022] Open
Abstract
Gene expression requires successful communication between enhancer and promoter regions, whose activities are regulated by a variety of factors and associated with distinct chromatin structures; in addition, functionally related genes and their regulatory repertoire tend to be arranged in the same subchromosomal regulatory domains. In this review, we discuss the importance of enhancers, especially clusters of enhancers (such as super-enhancers), as key regulatory hubs to integrate environmental cues and encode spatiotemporal instructions for genome expression, which are critical for a variety of biological processes governing mammalian development. Furthermore, we emphasize that the enhancer–promoter interaction landscape provides a critical context to understand the aetiologies and mechanisms behind numerous complex human diseases and provides new avenues for effective transcription-based interventions.
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178
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Molecular basis for the interaction between Integrator subunits IntS9 and IntS11 and its functional importance. Proc Natl Acad Sci U S A 2017; 114:4394-4399. [PMID: 28396433 DOI: 10.1073/pnas.1616605114] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The metazoan Integrator complex (INT) has important functions in the 3'-end processing of noncoding RNAs, including the uridine-rich small nuclear RNA (UsnRNA) and enhancer RNA (eRNA), and in the transcription of coding genes by RNA polymerase II. The INT contains at least 14 subunits, but its molecular mechanism of action is poorly understood, because currently there is little structural information about its subunits. The endonuclease activity of INT is mediated by its subunit 11 (IntS11), which belongs to the metallo-β-lactamase superfamily and is a paralog of CPSF-73, the endonuclease for pre-mRNA 3'-end processing. IntS11 forms a stable complex with Integrator complex subunit 9 (IntS9) through their C-terminal domains (CTDs). Here, we report the crystal structure of the IntS9-IntS11 CTD complex at 2.1-Å resolution and detailed, structure-based biochemical and functional studies. The complex is composed of a continuous nine-stranded β-sheet with four strands from IntS9 and five from IntS11. Highly conserved residues are located in the extensive interface between the two CTDs. Yeast two-hybrid assays and coimmunoprecipitation experiments confirm the structural observations on the complex. Functional studies demonstrate that the IntS9-IntS11 interaction is crucial for the role of INT in snRNA 3'-end processing.
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179
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Ssb1 and Ssb2 cooperate to regulate mouse hematopoietic stem and progenitor cells by resolving replicative stress. Blood 2017; 129:2479-2492. [PMID: 28270450 DOI: 10.1182/blood-2016-06-725093] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 02/26/2017] [Indexed: 12/14/2022] Open
Abstract
Hematopoietic stem and progenitor cells (HSPCs) are vulnerable to endogenous damage and defects in DNA repair can limit their function. The 2 single-stranded DNA (ssDNA) binding proteins SSB1 and SSB2 are crucial regulators of the DNA damage response; however, their overlapping roles during normal physiology are incompletely understood. We generated mice in which both Ssb1 and Ssb2 were constitutively or conditionally deleted. Constitutive Ssb1/Ssb2 double knockout (DKO) caused early embryonic lethality, whereas conditional Ssb1/Ssb2 double knockout (cDKO) in adult mice resulted in acute lethality due to bone marrow failure and intestinal atrophy featuring stem and progenitor cell depletion, a phenotype unexpected from the previously reported single knockout models of Ssb1 or Ssb2 Mechanistically, cDKO HSPCs showed altered replication fork dynamics, massive accumulation of DNA damage, genome-wide double-strand breaks enriched at Ssb-binding regions and CpG islands, together with the accumulation of R-loops and cytosolic ssDNA. Transcriptional profiling of cDKO HSPCs revealed the activation of p53 and interferon (IFN) pathways, which enforced cell cycling in quiescent HSPCs, resulting in their apoptotic death. The rapid cell death phenotype was reproducible in in vitro cultured cDKO-hematopoietic stem cells, which were significantly rescued by nucleotide supplementation or after depletion of p53. Collectively, Ssb1 and Ssb2 control crucial aspects of HSPC function, including proliferation and survival in vivo by resolving replicative stress to maintain genomic stability.
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180
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van den Berg DLC, Azzarelli R, Oishi K, Martynoga B, Urbán N, Dekkers DHW, Demmers JA, Guillemot F. Nipbl Interacts with Zfp609 and the Integrator Complex to Regulate Cortical Neuron Migration. Neuron 2017; 93:348-361. [PMID: 28041881 PMCID: PMC5263256 DOI: 10.1016/j.neuron.2016.11.047] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 10/10/2016] [Accepted: 11/17/2016] [Indexed: 12/18/2022]
Abstract
Mutations in NIPBL are the most frequent cause of Cornelia de Lange syndrome (CdLS), a developmental disorder encompassing several neurological defects, including intellectual disability and seizures. How NIPBL mutations affect brain development is not understood. Here we identify Nipbl as a functional interaction partner of the neural transcription factor Zfp609 in brain development. Depletion of Zfp609 or Nipbl from cortical neural progenitors in vivo is detrimental to neuronal migration. Zfp609 and Nipbl overlap at genomic binding sites independently of cohesin and regulate genes that control cortical neuron migration. We find that Zfp609 and Nipbl interact with the Integrator complex, which functions in RNA polymerase 2 pause release. Indeed, Zfp609 and Nipbl co-localize at gene promoters containing paused RNA polymerase 2, and Integrator similarly regulates neuronal migration. Our data provide a rationale and mechanistic insights for the role of Nipbl in the neurological defects associated with CdLS.
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Affiliation(s)
| | - Roberta Azzarelli
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK
| | - Koji Oishi
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK
| | - Ben Martynoga
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK
| | - Noelia Urbán
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK
| | - Dick H W Dekkers
- Center for Proteomics, Erasmus MC, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - Jeroen A Demmers
- Center for Proteomics, Erasmus MC, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - François Guillemot
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK.
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181
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Abstract
Transcription occurring at gene loci results in accumulation of mature RNA molecules (i.e., mRNAs) that can be easily assayed by RT-PCR or RNA sequencing. However, the steady-state level of RNA does not accurately mirror transcriptional activity per se. In fact, RNA stability plays a major role in determining the relative abundance of any given RNA molecule. Here, I describe a protocol of Nuclear Run-On assay coupled to deep sequencing to assess real-time transcription from engaged RNA polymerase. Mapping nascent transcripts at the genome-wide scale provides a reliable measure of transcriptional activity in mammalian cells and delivers a high-resolution map of coding and noncoding transcripts that is especially useful for annotation and quantification of short-lived RNA molecules.
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182
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Jarroux J, Morillon A, Pinskaya M. History, Discovery, and Classification of lncRNAs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1008:1-46. [PMID: 28815535 DOI: 10.1007/978-981-10-5203-3_1] [Citation(s) in RCA: 555] [Impact Index Per Article: 79.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The RNA World Hypothesis suggests that prebiotic life revolved around RNA instead of DNA and proteins. Although modern cells have changed significantly in 4 billion years, RNA has maintained its central role in cell biology. Since the discovery of DNA at the end of the nineteenth century, RNA has been extensively studied. Many discoveries such as housekeeping RNAs (rRNA, tRNA, etc.) supported the messenger RNA model that is the pillar of the central dogma of molecular biology, which was first devised in the late 1950s. Thirty years later, the first regulatory non-coding RNAs (ncRNAs) were initially identified in bacteria and then in most eukaryotic organisms. A few long ncRNAs (lncRNAs) such as H19 and Xist were characterized in the pre-genomic era but remained exceptions until the early 2000s. Indeed, when the sequence of the human genome was published in 2001, studies showed that only about 1.2% encodes proteins, the rest being deemed "non-coding." It was later shown that the genome is pervasively transcribed into many ncRNAs, but their functionality remained controversial. Since then, regulatory lncRNAs have been characterized in many species and were shown to be involved in processes such as development and pathologies, revealing a new layer of regulation in eukaryotic cells. This newly found focus on lncRNAs, together with the advent of high-throughput sequencing, was accompanied by the rapid discovery of many novel transcripts which were further characterized and classified according to specific transcript traits.In this review, we will discuss the many discoveries that led to the study of lncRNAs, from Friedrich Miescher's "nuclein" in 1869 to the elucidation of the human genome and transcriptome in the early 2000s. We will then focus on the biological relevance during lncRNA evolution and describe their basic features as genes and transcripts. Finally, we will present a non-exhaustive catalogue of lncRNA classes, thus illustrating the vast complexity of eukaryotic transcriptomes.
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Affiliation(s)
- Julien Jarroux
- ncRNA, epigenetic and genome fluidity, Institut Curie, Centre de Recherche, CNRS UMR 3244, PSL Research University and Université Pierre et Marie Curie, Paris, France
| | - Antonin Morillon
- ncRNA, epigenetic and genome fluidity, Institut Curie, Centre de Recherche, CNRS UMR 3244, PSL Research University and Université Pierre et Marie Curie, Paris, France.
| | - Marina Pinskaya
- ncRNA, epigenetic and genome fluidity, Institut Curie, Centre de Recherche, CNRS UMR 3244, PSL Research University and Université Pierre et Marie Curie, Paris, France
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183
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Epstein-Barr virus super-enhancer eRNAs are essential for MYC oncogene expression and lymphoblast proliferation. Proc Natl Acad Sci U S A 2016; 113:14121-14126. [PMID: 27864512 DOI: 10.1073/pnas.1616697113] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Epstein-Barr virus (EBV) super-enhancers (ESEs) are essential for lymphoblastoid cell (LCL) growth and survival. Reanalyses of LCL global run-on sequencing (Gro-seq) data found abundant enhancer RNAs (eRNAs) being transcribed at ESEs. Inactivation of ESE components, EBV nuclear antigen 2 (EBNA2) and bromodomain-containing protein 4 (BRD4), significantly decreased eRNAs at ESEs -428 and -525 kb upstream of the MYC oncogene transcription start site (TSS). shRNA knockdown of the MYC -428 and -525 ESE eRNA caused LCL growth arrest and reduced cell growth. Furthermore, MYC ESE eRNA knockdown also significantly reduced MYC expression, ESE H3K27ac signals, and MYC ESEs looping to MYC TSS. These data indicate that ESE eRNAs strongly affect cell gene expression and enable LCL growth.
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184
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Melamed P, Yosefzon Y, Rudnizky S, Pnueli L. Transcriptional enhancers: Transcription, function and flexibility. Transcription 2016; 7:26-31. [PMID: 26934309 DOI: 10.1080/21541264.2015.1128517] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Active transcriptional enhancers are often transcribed to eRNAs, whose changing levels mirror those of the target gene mRNA. We discuss some of the reported functions of these eRNAs and their likely diversity to allow utilization of distinct cis regulatory regions to enhance transcription in diverse developmental and cellular contexts.
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Affiliation(s)
- Philippa Melamed
- a Faculty of Biology, Technion-Israel Institute of Technology , Haifa , Israel
| | - Yahav Yosefzon
- a Faculty of Biology, Technion-Israel Institute of Technology , Haifa , Israel
| | - Sergei Rudnizky
- a Faculty of Biology, Technion-Israel Institute of Technology , Haifa , Israel
| | - Lilach Pnueli
- a Faculty of Biology, Technion-Israel Institute of Technology , Haifa , Israel
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185
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Liu Y, Li S, Chen Y, Kimberlin AN, Cahoon EB, Yu B. snRNA 3' End Processing by a CPSF73-Containing Complex Essential for Development in Arabidopsis. PLoS Biol 2016; 14:e1002571. [PMID: 27780203 PMCID: PMC5079582 DOI: 10.1371/journal.pbio.1002571] [Citation(s) in RCA: 13] [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: 08/04/2016] [Accepted: 09/26/2016] [Indexed: 01/26/2023] Open
Abstract
Uridine-rich small nuclear RNAs (snRNAs) are the basal components of the spliceosome and play essential roles in splicing. The biogenesis of the majority of snRNAs involves 3′ end endonucleolytic cleavage of the nascent transcript from the elongating DNA-dependent RNA ploymerase II. However, the protein factors responsible for this process remain elusive in plants. Here, we show that DEFECTIVE in snRNA PROCESSING 1 (DSP1) is an essential protein for snRNA 3′ end maturation in Arabidopsis. A hypomorphic dsp1-1 mutation causes pleiotropic developmental defects, impairs the 3′ end processing of snRNAs, increases the levels of snRNA primary transcripts (pre-snRNAs), and alters the occupancy of Pol II at snRNA loci. In addition, DSP1 binds snRNA loci and interacts with Pol-II in a DNA/RNA-dependent manner. We further show that DSP1 forms a conserved complex, which contains at least four additional proteins, to catalyze snRNA 3′ end maturation in Arabidopsis. The catalytic component of this complex is likely the cleavage and polyadenylation specificity factor 73 kDa-I (CSPF73-I), which is the nuclease cleaving the pre-mRNA 3′ end. However, the DSP1 complex does not affect pre-mRNA 3′ end cleavage, suggesting that plants may use different CPSF73-I-containing complexes to process snRNAs and pre-mRNAs. This study identifies a complex responsible for the snRNA 3′ end maturation in plants and uncovers a previously unknown function of CPSF73 in snRNA maturation. This study identifies a protein complex in plants that is responsible for the maturation of the 3′ ends of spliceosomal snRNAs and uncovers a novel function for the mRNA 3′ cleavage nuclease CPSF73. snRNAs form the RNA components of the spliceosome and are required for spliceosome formation and splicing. The generation of snRNAs involves 3′ end endonucleolytic cleavage of primary snRNA transcripts (pre-snRNAs). The factors responsible for pre-snRNA 3′ end cleavage are known in metazoans, but many of these components are missing in plants. Therefore, the proteins that catalyze pre-snRNA cleavage in plants and the mechanism leading to plant snRNA 3′ maturation are unknown. Here, we show that a DSP1 complex (containing DSP1, DSP2, DSP3, DSP4, and CPFS73-I) is responsible for pre-snRNA 3′ end cleavage in Arabidopsis. We further show that CPSF73-I, which is known to cleave the pre-mRNA 3′ end, is likely the enzyme also catalyzing snRNA 3′ end maturation in plants. Interestingly, plants appear to use two different CPSF73-I-containing complexes to catalyze the maturation of mRNAs and snRNAs. The study thereby identifies an snRNA-processing complex in plants and also elucidates a new role for CPSF73-I in this process.
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Affiliation(s)
- Yunfeng Liu
- Center for Plant Science Innovation and School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Shengjun Li
- Center for Plant Science Innovation and School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Yuan Chen
- Plant Gene Expression Center, US Department of Agriculture-Agricultural Research Service, University of California-Berkeley, Albany, California, United States of America
| | - Athen N. Kimberlin
- Center for Plant Science Innovation and Department of Biochemistry, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Edgar B. Cahoon
- Center for Plant Science Innovation and Department of Biochemistry, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Bin Yu
- Center for Plant Science Innovation and School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
- * E-mail:
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186
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Kashkin KN, Sverdlov ED. Properties, functions, and therapeutic prospects of enhancer RNAs. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2016. [DOI: 10.1134/s1068162016050083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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187
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CRISPR-Cas9 mediated genetic engineering for the purification of the endogenous integrator complex from mammalian cells. Protein Expr Purif 2016; 128:101-8. [PMID: 27546450 DOI: 10.1016/j.pep.2016.08.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 08/12/2016] [Accepted: 08/16/2016] [Indexed: 01/14/2023]
Abstract
The Integrator Complex (INT) is a large multi-subunit protein complex, containing at least 14 subunits and a host of associated factors. These protein components have been established through pulldowns of overexpressed epitope tagged subunits or by using antibodies raised against specific subunits. Here, we utilize CRISPR/Cas9 gene editing technology to introduce N-terminal FLAG epitope tags into the endogenous genes that encode Integrator subunit 4 and 11 within HEK293T cells. We provide specific details regarding design, approaches for facile screening, and our observed frequency of successful recombination. Finally, using silver staining, Western blotting and LC-MS/MS we compare the components of INT of purifications from CRISPR derived lines to 293T cells overexpressing FLAG-INTS11 to define a highly resolved constituency of mammalian INT.
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188
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Chen LL. Linking Long Noncoding RNA Localization and Function. Trends Biochem Sci 2016; 41:761-772. [PMID: 27499234 DOI: 10.1016/j.tibs.2016.07.003] [Citation(s) in RCA: 703] [Impact Index Per Article: 87.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/23/2016] [Accepted: 07/01/2016] [Indexed: 02/06/2023]
Abstract
Recent studies have revealed the regulatory potential of many long noncoding RNAs (lncRNAs). Most lncRNAs, like mRNAs, are transcribed by RNA polymerase II and are capped, polyadenylated, and spliced. However, the subcellular fates of lncRNAs are distinct and the mechanisms of action are diverse. Investigating the mechanisms that determine the subcellular fate of lncRNAs has the potential to provide new insights into their biogenesis and specialized functions.
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Affiliation(s)
- Ling-Ling Chen
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China; School of Life Science and Technology, Shanghai Tech University, 100 Haike Road, Shanghai, China.
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189
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Beagrie RA, Pombo A. Gene activation by metazoan enhancers: Diverse mechanisms stimulate distinct steps of transcription. Bioessays 2016; 38:881-93. [PMID: 27452946 DOI: 10.1002/bies.201600032] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Enhancers can stimulate transcription by a number of different mechanisms which control different stages of the transcription cycle of their target genes, from recruitment of the transcription machinery to elongation by RNA polymerase. These mechanisms may not be mutually exclusive, as a single enhancer may act through different pathways by binding multiple transcription factors. Multiple enhancers may also work together to regulate transcription of a shared target gene. Most of the evidence supporting different enhancer mechanisms comes from the study of single genes, but new high-throughput experimental frameworks offer the opportunity to integrate and generalize disparate mechanisms identified at single genes. This effort is especially important if we are to fully understand how sequence variation within enhancers contributes to human disease.
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Affiliation(s)
- Robert A Beagrie
- Epigenetic Regulation and Chromatin Architecture Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany
| | - Ana Pombo
- Epigenetic Regulation and Chromatin Architecture Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany
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190
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Vernimmen D, Bickmore WA. The Hierarchy of Transcriptional Activation: From Enhancer to Promoter. Trends Genet 2016; 31:696-708. [PMID: 26599498 DOI: 10.1016/j.tig.2015.10.004] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/18/2015] [Accepted: 10/15/2015] [Indexed: 12/20/2022]
Abstract
Regulatory elements (enhancers) that are remote from promoters play a critical role in the spatial, temporal, and physiological control of gene expression. Studies on specific loci, together with genome-wide approaches, suggest that there may be many common mechanisms involved in enhancer-promoter communication. Here, we discuss the multiprotein complexes that are recruited to enhancers and the hierarchy of events taking place between regulatory elements and promoters.
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Affiliation(s)
- Douglas Vernimmen
- The Roslin Institute, Developmental Biology Division, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK.
| | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
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191
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Rienzo M, Casamassimi A. Integrator complex and transcription regulation: Recent findings and pathophysiology. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1859:1269-80. [PMID: 27427483 DOI: 10.1016/j.bbagrm.2016.07.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/08/2016] [Accepted: 07/12/2016] [Indexed: 12/20/2022]
Abstract
In the last decade, a novel molecular complex has been added to the RNA polymerase II-mediated transcription machinery as one of the major components. This multiprotein complex, named Integrator, plays a pivotal role in the regulation of most RNA Polymerase II-dependent genes. This complex consists of at least 14 different subunits. However, studies investigating its structure and composition are still lacking. Although it was originally discovered as a complex implicated in the 3'-end formation of noncoding small nuclear RNAs, recent studies indicate additional roles for Integrator in transcription regulation, for example during transcription pause-release and elongation of polymerase, in the biogenesis of transcripts derived from enhancers, as well as in DNA and RNA metabolism for some of its components. Noteworthy, several subunits have been emerging to play roles during development and differentiation; more importantly, their alterations are likely to be involved in several human pathologies, including cancer and lung diseases.
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Affiliation(s)
- Monica Rienzo
- Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Via L. De Crecchio 7, 80138 Naples, Italy
| | - Amelia Casamassimi
- Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Via L. De Crecchio 7, 80138 Naples, Italy.
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192
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Abstract
RNA polymerase 2 (pol2) associates with enhancers and promoters, followed by transcription initiation and subsequent pausing. Upon release, pol2 proceeds into productive elongation. A wide spread view of transcription holds that during elongation, pol2 and associated factors clear the promoter proximal region to track along the chromatin fiber until a termination site is encountered. However, several studies are compatible with alternative models. One common feature among these models is that transcription elongation results from movement of the gene along a complex consisting of pol2 and associated factors. Such a scenario predicts that active enhancers and promoters that are bound by transcription complexes, including pol2 are in dynamic physical proximity with the gene body in a manner paralleling pol2 processivity. This has indeed been observed by chromosome conformation capture under conditions of synchronous transcription. Here we discuss these observations and their implication for architectural models of transcription elongation.
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Affiliation(s)
- Kiwon Lee
- a Division of Hematology , The Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | - Gerd A Blobel
- a Division of Hematology , The Children's Hospital of Philadelphia , Philadelphia , PA , USA.,b Perelman School of Medicine , University of Pennsylvania , Philadelphia , PA , USA
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193
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Kim TK, Shiekhattar R. Diverse regulatory interactions of long noncoding RNAs. Curr Opin Genet Dev 2016; 36:73-82. [PMID: 27151434 DOI: 10.1016/j.gde.2016.03.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 03/31/2016] [Indexed: 02/03/2023]
Abstract
Long noncoding RNAs (lncRNAs) are emerging as important regulators of diverse biological functions. Studies in the past decade indicate that a large number of lncRNAs are enriched in the nucleus and originate from transcriptionally active regulatory elements. These lncRNAs associate with transcription factors and chromatin regulatory elements to fine-tune the transcriptional output of protein coding genes. Importantly, lncRNAs display exquisite tissue specificity in their expression. Understanding how lncRNAs associate with their protein or nucleic acid partners and how they modulate gene expression provides insight into their scope of biological function. This review discusses notable functional properties and mechanisms of action of lncRNAs that have resulted from recent progress made in the field.
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Affiliation(s)
- Tae-Kyung Kim
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Ramin Shiekhattar
- Sylvester Comprehensive Cancer Center, Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA.
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194
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Liu T, Zhang J, Zhou T. Effect of Interaction between Chromatin Loops on Cell-to-Cell Variability in Gene Expression. PLoS Comput Biol 2016; 12:e1004917. [PMID: 27153118 PMCID: PMC4859557 DOI: 10.1371/journal.pcbi.1004917] [Citation(s) in RCA: 17] [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: 02/04/2016] [Accepted: 04/14/2016] [Indexed: 01/09/2023] Open
Abstract
According to recent experimental evidence, the interaction between chromatin loops, which can be characterized by three factors-connection pattern, distance between regulatory elements, and communication form, play an important role in determining the level of cell-to-cell variability in gene expression. These quantitative experiments call for a corresponding modeling effect that addresses the question of how changes in these factors affect variability at the expression level in a systematic rather than case-by-case fashion. Here we make such an effort, based on a mechanic model that maps three fundamental patterns for two interacting DNA loops into a 4-state model of stochastic transcription. We first show that in contrast to side-by-side loops, nested loops enhance mRNA expression and reduce expression noise whereas alternating loops have just opposite effects. Then, we compare effects of facilitated tracking and direct looping on gene expression. We find that the former performs better than the latter in controlling mean expression and in tuning expression noise, but this control or tuning is distance-dependent, remarkable for moderate loop lengths, and there is a limit loop length such that the difference in effect between two communication forms almost disappears. Our analysis and results justify the facilitated chromatin-looping hypothesis.
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Affiliation(s)
- Tuoqi Liu
- School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Jiajun Zhang
- School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou, People’s Republic of China
- Guangdong Province Key Laboratory of Computational Science, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Tianshou Zhou
- School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou, People’s Republic of China
- Guangdong Province Key Laboratory of Computational Science, Sun Yat-Sen University, Guangzhou, People’s Republic of China
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195
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Rutenberg-Schoenberg M, Sexton AN, Simon MD. The Properties of Long Noncoding RNAs That Regulate Chromatin. Annu Rev Genomics Hum Genet 2016; 17:69-94. [PMID: 27147088 DOI: 10.1146/annurev-genom-090314-024939] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Beyond coding for proteins, RNA molecules have well-established functions in the posttranscriptional regulation of gene expression. Less clear are the upstream roles of RNA in regulating transcription and chromatin-based processes in the nucleus. RNA is transcribed in the nucleus, so it is logical that RNA could play diverse and broad roles that would impact human physiology. Indeed, this idea is supported by well-established examples of noncoding RNAs that affect chromatin structure and function. There has been dramatic growth in studies focused on the nuclear roles of long noncoding RNAs (lncRNAs). Although little is known about the biochemical mechanisms of these lncRNAs, there is a developing consensus regarding the challenges of defining lncRNA function and mechanism. In this review, we examine the definition, discovery, functions, and mechanisms of lncRNAs. We emphasize areas where challenges remain and where consensus among laboratories has underscored the exciting ways in which human lncRNAs may affect chromatin biology.
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Affiliation(s)
- Michael Rutenberg-Schoenberg
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511; , , .,Chemical Biology Institute, Yale University, West Haven, Connecticut 06516
| | - Alec N Sexton
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511; , , .,Chemical Biology Institute, Yale University, West Haven, Connecticut 06516
| | - Matthew D Simon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511; , , .,Chemical Biology Institute, Yale University, West Haven, Connecticut 06516
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196
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Abstract
Long non-coding RNAs (lncRNAs) are a diverse class of RNAs that engage in numerous biological processes across every branch of life. Although initially discovered as mRNA-like transcripts that do not encode proteins, recent studies have revealed features of lncRNAs that further distinguish them from mRNAs. In this Review, we describe special events in the lifetimes of lncRNAs - before, during and after transcription - and discuss how these events ultimately shape the unique characteristics and functional roles of lncRNAs.
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Affiliation(s)
- Jeffrey J Quinn
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, California 94305, USA.,Department of Bioengineering, Stanford University School of Medicine and School of Engineering, Stanford, California 94305, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, California 94305, USA
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197
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Corujo D, Mas G, Malinverni R, Di Croce L, Buschbeck M. Barcelona conference on epigenetics and cancer 2015: Coding and non-coding functions of the genome. Epigenetics 2016; 11:95-100. [PMID: 26996885 DOI: 10.1080/15592294.2015.1131377] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The Barcelona Conference on Epigenetics and Cancer (BCEC) entitled "Coding and Non-Coding functions of the Genome" took place October 29-30, 2015 in Barcelona. The 2015 BCEC was the third edition of a series of annual conferences jointly organized by 5 leading research centers in Barcelona together with B-Debate, an initiative of BioCat. Luciano Di Croce from the Center for Genomic Regulation and Marcus Buschbeck from the Josep Carreras Leukemia Research Institute put together the scientific program with a particular focus on the role of non-coding RNAs in enhancer regulation, epigenetic control by Polycomb complexes, histone variants, and nuclear organization. In one and a half days, 22 talks and 56 posters were presented to an audience of 215 participants.
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Affiliation(s)
- David Corujo
- a Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Crta. Can Ruti, Cami de les Escoles , Badalona , Spain
| | - Gloria Mas
- b Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88 , Barcelona , Spain.,c Universitat Pompeu Fabra (UPF) , Barcelona , Spain
| | - Roberto Malinverni
- a Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Crta. Can Ruti, Cami de les Escoles , Badalona , Spain
| | - Luciano Di Croce
- b Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88 , Barcelona , Spain.,c Universitat Pompeu Fabra (UPF) , Barcelona , Spain.,d Institució Catalana de Recerca i Estudis Avançats, Passeig Lluis Companys 23 , Barcelona , Spain
| | - Marcus Buschbeck
- a Josep Carreras Leukaemia Research Institute (IJC), Campus ICO - Germans Trias i Pujol, Campus Can Ruti, Crta. Can Ruti, Cami de les Escoles , Badalona , Spain
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198
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Langdon YG, Fuentes R, Zhang H, Abrams EW, Marlow FL, Mullins MC. Split top: a maternal cathepsin B that regulates dorsoventral patterning and morphogenesis. Development 2016; 143:1016-28. [PMID: 26893345 PMCID: PMC4813285 DOI: 10.1242/dev.128900] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 01/29/2016] [Indexed: 12/28/2022]
Abstract
The vertebrate embryonic dorsoventral axis is established and patterned by Wnt and bone morphogenetic protein (BMP) signaling pathways, respectively. Whereas Wnt signaling establishes the dorsal side of the embryo and induces the dorsal organizer, a BMP signaling gradient patterns tissues along the dorsoventral axis. Early Wnt signaling is provided maternally, whereas BMP ligand expression in the zebrafish is zygotic, but regulated by maternal factors. Concomitant with BMP activity patterning dorsoventral axial tissues, the embryo also undergoes dramatic morphogenetic processes, including the cell movements of gastrulation, epiboly and dorsal convergence. Although the zygotic regulation of these cell migration processes is increasingly understood, far less is known of the maternal regulators of these processes. Similarly, the maternal regulation of dorsoventral patterning, and in particular the maternal control of ventral tissue specification, is poorly understood. We identified split top, a recessive maternal-effect zebrafish mutant that disrupts embryonic patterning upstream of endogenous BMP signaling. Embryos from split top mutant females exhibit a dorsalized embryonic axis, which can be rescued by BMP misexpression or by derepressing endogenous BMP signaling. In addition to dorsoventral patterning defects, split top mutants display morphogenesis defects that are both BMP dependent and independent. These morphogenesis defects include incomplete dorsal convergence, delayed epiboly progression and an early lysis phenotype during gastrula stages. The latter two morphogenesis defects are associated with disruption of the actin and microtubule cytoskeleton within the yolk cell and defects in the outer enveloping cell layer, which are both known mediators of epiboly movements. Through chromosomal mapping and RNA sequencing analysis, we identified the lysosomal endopeptidase cathepsin Ba (ctsba) as the gene deficient in split top embryos. Our results identify a novel role for Ctsba in morphogenesis and expand our understanding of the maternal regulation of dorsoventral patterning.
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Affiliation(s)
- Yvette G Langdon
- University of Pennsylvania Perelman School of Medicine, Department of Cell and Developmental Biology, 421 Curie Blvd., Philadelphia, PA 19104, USA Millsaps College, Department of Biology, Jackson, MS 39210, USA
| | - Ricardo Fuentes
- University of Pennsylvania Perelman School of Medicine, Department of Cell and Developmental Biology, 421 Curie Blvd., Philadelphia, PA 19104, USA
| | - Hong Zhang
- University of Pennsylvania Perelman School of Medicine, Department of Cell and Developmental Biology, 421 Curie Blvd., Philadelphia, PA 19104, USA
| | - Elliott W Abrams
- University of Pennsylvania Perelman School of Medicine, Department of Cell and Developmental Biology, 421 Curie Blvd., Philadelphia, PA 19104, USA
| | - Florence L Marlow
- University of Pennsylvania Perelman School of Medicine, Department of Cell and Developmental Biology, 421 Curie Blvd., Philadelphia, PA 19104, USA
| | - Mary C Mullins
- University of Pennsylvania Perelman School of Medicine, Department of Cell and Developmental Biology, 421 Curie Blvd., Philadelphia, PA 19104, USA
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199
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Li W, Notani D, Rosenfeld MG. Enhancers as non-coding RNA transcription units: recent insights and future perspectives. Nat Rev Genet 2016; 17:207-23. [PMID: 26948815 DOI: 10.1038/nrg.2016.4] [Citation(s) in RCA: 481] [Impact Index Per Article: 60.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Networks of regulatory enhancers dictate distinct cell identities and cellular responses to diverse signals by instructing precise spatiotemporal patterns of gene expression. However, 35 years after their discovery, enhancer functions and mechanisms remain incompletely understood. Intriguingly, recent evidence suggests that many, if not all, functional enhancers are themselves transcription units, generating non-coding enhancer RNAs. This observation provides a fundamental insight into the inter-regulation between enhancers and promoters, which can both act as transcription units; it also raises crucial questions regarding the potential biological roles of the enhancer transcription process and non-coding enhancer RNAs. Here, we review research progress in this field and discuss several important, unresolved questions regarding the roles and mechanisms of enhancers in gene regulation.
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Affiliation(s)
- Wenbo Li
- Howard Hughes Medical Institute, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92037-0648, USA
| | - Dimple Notani
- Howard Hughes Medical Institute, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92037-0648, USA
| | - Michael G Rosenfeld
- Howard Hughes Medical Institute, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92037-0648, USA
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200
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Fang Y, Fullwood MJ. Roles, Functions, and Mechanisms of Long Non-coding RNAs in Cancer. GENOMICS PROTEOMICS & BIOINFORMATICS 2016; 14:42-54. [PMID: 26883671 PMCID: PMC4792843 DOI: 10.1016/j.gpb.2015.09.006] [Citation(s) in RCA: 694] [Impact Index Per Article: 86.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 08/31/2015] [Accepted: 09/17/2015] [Indexed: 12/28/2022]
Abstract
Long non-coding RNAs (lncRNAs) play important roles in cancer. They are involved in chromatin remodeling, as well as transcriptional and post-transcriptional regulation, through a variety of chromatin-based mechanisms and via cross-talk with other RNA species. lncRNAs can function as decoys, scaffolds, and enhancer RNAs. This review summarizes the characteristics of lncRNAs, including their roles, functions, and working mechanisms, describes methods for identifying and annotating lncRNAs, and discusses future opportunities for lncRNA-based therapies using antisense oligonucleotides.
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Affiliation(s)
- Yiwen Fang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Melissa J Fullwood
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore; Yale-NUS Liberal Arts College, Singapore 138527, Singapore.
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