51
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Islam R, Lai C. A Brief Overview of lncRNAs in Endothelial Dysfunction-Associated Diseases: From Discovery to Characterization. EPIGENOMES 2019; 3:epigenomes3030020. [PMID: 34968230 PMCID: PMC8594677 DOI: 10.3390/epigenomes3030020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 11/16/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) are a novel class of regulatory RNA molecules and they are involved in many biological processes and disease developments. Several unique features of lncRNAs have been identified, such as tissue-and/or cell-specific expression pattern, which suggest that they could be potential candidates for therapeutic and diagnostic applications. More recently, the scope of lncRNA studies has been extended to endothelial biology research. Many of lncRNAs were found to be critically involved in the regulation of endothelial function and its associated disease progression. An improved understanding of endothelial biology can thus facilitate the discovery of novel biomarkers and therapeutic targets for endothelial dysfunction-associated diseases, such as abnormal angiogenesis, hypertension, diabetes, and atherosclerosis. Nevertheless, the underlying mechanism of lncRNA remains undefined in previous published studies. Therefore, in this review, we aimed to discuss the current methodologies for discovering and investigating the functions of lncRNAs and, in particular, to address the functions of selected lncRNAs in endothelial dysfunction-associated diseases.
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Affiliation(s)
- Rashidul Islam
- Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hong Kong, China;
| | - Christopher Lai
- Health and Social Sciences Cluster, Singapore Institute of Technology, Singapore 138683, Singapore
- Correspondence: ; Tel.: +65-6592-1045
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52
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Regulation of CCL2 expression in human vascular endothelial cells by a neighboring divergently transcribed long noncoding RNA. Proc Natl Acad Sci U S A 2019; 116:16410-16419. [PMID: 31350345 PMCID: PMC6697820 DOI: 10.1073/pnas.1904108116] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Controlling vascular inflammation is critical for limiting the progression of chronic vascular diseases such as atherosclerosis. Although poorly studied in the context of human vascular inflammation, long noncoding RNAs (lncRNAs) have the potential to regulate their neighboring genes. However, what constitutes a neighboring lncRNA is currently not well defined. In this study, we took an innovative approach to define IL-1β−regulated neighboring mRNA−lncRNA pairs based on colocalization within the same chromatin neighborhood and divergent transcriptional orientation. This approach led to the discovery of lncRNA-CCL2, which positively regulates its neighboring gene, CCL2, an important player in atherogenesis. Furthermore, lncRNA-CCL2 is relevant to human disease, as it is elevated in human atherosclerotic plaques, and, given its regulatory role, it may contribute to atherogenesis. Atherosclerosis is a chronic inflammatory disease that is driven, in part, by activation of vascular endothelial cells (ECs). In response to inflammatory stimuli, the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway orchestrates the expression of a network of EC genes that contribute to monocyte recruitment and diapedesis across the endothelium. Although many long noncoding RNAs (lncRNAs) are dysregulated in atherosclerosis, they remain poorly characterized, especially in the context of human vascular inflammation. Prior studies have illustrated that lncRNAs can regulate their neighboring protein-coding genes via interaction with protein complexes. We therefore identified and characterized neighboring interleukin-1β (IL-1β)−regulated messenger RNA (mRNA)−lncRNA pairs in ECs. We found these pairs to be highly correlated in expression, especially when located within the same chromatin territory. Additionally, these pairs were predominantly divergently transcribed and shared common gene regulatory elements, characterized by active histone marks and NF-κB binding. Further analysis was performed on lncRNA-CCL2, which is transcribed divergently to the gene, CCL2, encoding a proatherosclerotic chemokine. LncRNA-CCL2 and CCL2 showed coordinate up-regulation in response to inflammatory stimuli, and their expression was correlated in unstable symptomatic human atherosclerotic plaques. Knock-down experiments revealed that lncRNA-CCL2 positively regulated CCL2 mRNA levels in multiple primary ECs and EC cell lines. This regulation appeared to involve the interaction of lncRNA-CCL2 with RNA binding proteins, including HNRNPU and IGF2BP2. Hence, our approach has uncovered a network of neighboring mRNA−lncRNA pairs in the setting of inflammation and identified the function of an lncRNA, lncRNA-CCL2, which may contribute to atherogenesis in humans.
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53
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Getz RA, Kwak G, Cornell S, Mbugua S, Eberhard J, Huang SX, Abbasi Z, de Medeiros AS, Thomas R, Bukowski B, Dranchak PK, Inglese J, Hoffman CS. A fission yeast platform for heterologous expression of mammalian adenylyl cyclases and high throughput screening. Cell Signal 2019; 60:114-121. [PMID: 31026495 DOI: 10.1016/j.cellsig.2019.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/12/2019] [Accepted: 04/22/2019] [Indexed: 01/18/2023]
Abstract
The fission yeast Schizosaccharomyces pombe uses a cAMP signaling pathway to link glucose-sensing to Protein Kinase A activity in order to regulate cell growth, sexual development, gluconeogenesis, and exit from stationary phase. We previously used a PKA-repressed fbp1-ura4 reporter to conduct high throughput screens (HTSs) for inhibitors of heterologously-expressed mammalian cyclic nucleotide phosphodiesterases (PDEs). Here, we describe the successful expression of all ten mammalian adenylyl cyclase (AC) genes, along with the human GNAS Gαs gene. By measuring expression of an fbp1-GFP reporter together with direct measurements of intracellular cAMP levels, we can detect both basal AC activity from all ten AC genes as well as GNAS-stimulated activity from eight of the nine transmembrane ACs (tmACs; AC2-AC9). The ability to use this platform to conduct HTS for novel chemical probes that reduce PKA activity was demonstrated by a pilot screen of the LOPAC®1280 library, leading to the identification of diphenyleneiodonium chloride (DPI) as an inhibitor of basal AC activity. This screening technology could open the door to the development of therapeutic compounds that target GNAS or the ACs, an area in which there is significant unmet need.
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Affiliation(s)
- Rachel A Getz
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA
| | - Grace Kwak
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA
| | - Stacie Cornell
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA
| | - Samuel Mbugua
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Jeremy Eberhard
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Sheng Xiang Huang
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Zainab Abbasi
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | | | - Rony Thomas
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Brett Bukowski
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Patricia K Dranchak
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA.
| | - James Inglese
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA.
| | - Charles S Hoffman
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
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54
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Liu XQ, Li BX, Zeng GR, Liu QY, Ai DM. Prediction of Long Non-Coding RNAs Based on Deep Learning. Genes (Basel) 2019; 10:genes10040273. [PMID: 30987229 PMCID: PMC6523782 DOI: 10.3390/genes10040273] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 03/29/2019] [Accepted: 03/29/2019] [Indexed: 01/09/2023] Open
Abstract
With the rapid development of high-throughput sequencing technology, a large number of transcript sequences have been discovered, and how to identify long non-coding RNAs (lncRNAs) from transcripts is a challenging task. The identification and inclusion of lncRNAs not only can more clearly help us to understand life activities themselves, but can also help humans further explore and study the disease at the molecular level. At present, the detection of lncRNAs mainly includes two forms of calculation and experiment. Due to the limitations of bio sequencing technology and ineluctable errors in sequencing processes, the detection effect of these methods is not very satisfactory. In this paper, we constructed a deep-learning model to effectively distinguish lncRNAs from mRNAs. We used k-mer embedding vectors obtained through training the GloVe algorithm as input features and set up the deep learning framework to include a bidirectional long short-term memory model (BLSTM) layer and a convolutional neural network (CNN) layer with three additional hidden layers. By testing our model, we have found that it obtained the best values of 97.9%, 96.4% and 99.0% in F1score, accuracy and auROC, respectively, which showed better classification performance than the traditional PLEK, CNCI and CPC methods for identifying lncRNAs. We hope that our model will provide effective help in distinguishing mature mRNAs from lncRNAs, and become a potential tool to help humans understand and detect the diseases associated with lncRNAs.
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Affiliation(s)
- Xiu-Qin Liu
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.
| | - Bing-Xiu Li
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.
| | - Guan-Rong Zeng
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.
| | - Qiao-Yue Liu
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.
| | - Dong-Mei Ai
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.
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55
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lncRNA transcriptional initiation induces chromatin remodeling within a limited range in the fission yeast fbp1 promoter. Sci Rep 2019; 9:299. [PMID: 30670704 PMCID: PMC6342983 DOI: 10.1038/s41598-018-36049-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 11/01/2018] [Indexed: 11/23/2022] Open
Abstract
Long noncoding RNAs (lncRNAs) transcribed across gene promoters have been detected. These regulate transcription by mechanisms that have not been fully elucidated. We herein show that the chromatin configuration is altered into an accessible state within 290 bp downstream from the initiation site of metabolic-stress-induced lncRNAs (mlonRNAs) in the promoter of the fission yeast fbp1 gene, whose transcription is massively induced upon glucose starvation. Chromatin upstream from fbp1 is progressively altered into an open configuration, as a cascade of transcription of three overlapping mlonRNA species (-a, -b and -c in order) occurs with transcriptional initiation sites progressing 5′ to 3′ upstream of the fbp1 promoter. Initiation of the shortest mlonRNA (mlonRNA-c) induces chromatin remodeling around a transcription factor-binding site and subsequent massive induction of fbp1. We identify the cis-element required for mlonRNA-c initiation, and by changing the distance between mlonRNA-initiation site and the transcription factor-binding site, we show that mlonRNA-initiation effectively induces chromatin remodeling in a limited distance within 290 bp. These results indicate that mlonRNAs are transcribed across the fbp1 promoter as a short-range inducer for local chromatin alterations, and suggest that strict chromatin modulation is archived via stepwise mlonRNA-initiations.
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56
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Zhen S, Li X. Application of CRISPR-Cas9 for Long Noncoding RNA Genes in Cancer Research. Hum Gene Ther 2019; 30:3-9. [PMID: 30045635 DOI: 10.1089/hum.2018.063] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Shuai Zhen
- Center for Translational Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- Key Laboratory for Tumor Precision Medicine of Shaanxi Province, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Xu Li
- Center for Translational Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- Key Laboratory for Tumor Precision Medicine of Shaanxi Province, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
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57
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Liu W, Liu X, Wu C, Jiang L. Transcriptome analysis demonstrates that long noncoding RNA is involved in the hypoxic response in Larimichthys crocea. FISH PHYSIOLOGY AND BIOCHEMISTRY 2018; 44:1333-1347. [PMID: 29948448 DOI: 10.1007/s10695-018-0525-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 05/23/2018] [Indexed: 06/08/2023]
Abstract
The large yellow croaker (Larimichthys crocea) has low hypoxia tolerance compared with other fish species, and the mRNA levels of hypoxia-inducible factor (HIF)-1α in its brain do not change markedly under hypoxic conditions. In this study, we investigated noncoding transcription in the hypoxic response mechanism of L. crocea. We generated a catalog of long noncoding RNAs (lncRNAs) from the brain of L. crocea individuals under hypoxic stress, investigated lncRNA expression patterns, and analyzed the HIF signaling pathway by RNA sequencing. Prolyl hydroxylase domain 2 (PHD2) expression significantly increased after 6 and 12 h of hypoxia, and a lncRNA (Linc_06633.1) was found in the upstream, antisense region of PHD2. Linc_06633.1 may be an important regulator that promotes PDH2 expression under hypoxia in L. crocea, and we constructed a regulatory profile of L. crocea under hypoxic conditions. To the best of our knowledge, it is the first study that has been conducted on hypoxia signaling pathway regulation by lncRNAs in L. crocea and elucidates the role played by lncRNAs in the regulation of the hypoxia stress response in teleost fish.
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Affiliation(s)
- Wei Liu
- National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, People's Republic of China
| | - Xiaoxu Liu
- National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, People's Republic of China
| | - Changwen Wu
- National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, People's Republic of China
| | - Lihua Jiang
- National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, People's Republic of China.
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58
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Histone Chaperone Asf1 Is Required for the Establishment of Repressive Chromatin in Schizosaccharomyces pombe fbp1 Gene Repression. Mol Cell Biol 2018; 38:MCB.00194-18. [PMID: 29967244 DOI: 10.1128/mcb.00194-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 06/23/2018] [Indexed: 11/20/2022] Open
Abstract
The arrangement of nucleosomes in chromatin plays a role in transcriptional regulation by restricting the accessibility of transcription factors and RNA polymerase II to cis-acting elements and promoters. For gene activation, the chromatin structure is altered to an open configuration. The mechanism for this process has been extensively analyzed. However, the mechanism by which repressive chromatin is reconstituted to terminate transcription has not been fully elucidated. Here, we investigated the mechanisms by which chromatin is reconstituted in the fission yeast Schizosaccharomyces pombefbp1 gene, which is robustly induced upon glucose starvation but tightly repressed under glucose-rich conditions. We found that the chromatin structure in the region upstream from fbp1 is closed by a two-step process. When cells are returned to glucose-rich medium following glucose starvation, changes in the nucleosome pattern alter the chromatin configuration at the transcription factor binding site to an inaccessible state, after which the nucleosome density upstream from fbp1 gradually increases via histone loading. Interestingly, this histone loading was observed in the absence of the Tup family corepressors Tup11 and Tup12. Analysis of strains carrying either gene disruptions or mutations affecting nine fission yeast histone chaperone genes demonstrated that the histone chaperone Asf1 induces nucleosome loading during glucose repression. These data establish a previously unappreciated chromatin reconstitution mechanism in fbp1 repression.
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59
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Liao K, Xu J, Yang W, You X, Zhong Q, Wang X. The research progress of LncRNA involved in the regulation of inflammatory diseases. Mol Immunol 2018; 101:182-188. [DOI: 10.1016/j.molimm.2018.05.030] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/23/2018] [Accepted: 05/31/2018] [Indexed: 02/07/2023]
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60
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Atkinson SR, Marguerat S, Bitton DA, Rodríguez-López M, Rallis C, Lemay JF, Cotobal C, Malecki M, Smialowski P, Mata J, Korber P, Bachand F, Bähler J. Long noncoding RNA repertoire and targeting by nuclear exosome, cytoplasmic exonuclease, and RNAi in fission yeast. RNA (NEW YORK, N.Y.) 2018; 24:1195-1213. [PMID: 29914874 PMCID: PMC6097657 DOI: 10.1261/rna.065524.118] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 06/14/2018] [Indexed: 05/31/2023]
Abstract
Long noncoding RNAs (lncRNAs), which are longer than 200 nucleotides but often unstable, contribute a substantial and diverse portion to pervasive noncoding transcriptomes. Most lncRNAs are poorly annotated and understood, although several play important roles in gene regulation and diseases. Here we systematically uncover and analyze lncRNAs in Schizosaccharomyces pombe. Based on RNA-seq data from twelve RNA-processing mutants and nine physiological conditions, we identify 5775 novel lncRNAs, nearly 4× the previously annotated lncRNAs. The expression of most lncRNAs becomes strongly induced under the genetic and physiological perturbations, most notably during late meiosis. Most lncRNAs are cryptic and suppressed by three RNA-processing pathways: the nuclear exosome, cytoplasmic exonuclease, and RNAi. Double-mutant analyses reveal substantial coordination and redundancy among these pathways. We classify lncRNAs by their dominant pathway into cryptic unstable transcripts (CUTs), Xrn1-sensitive unstable transcripts (XUTs), and Dicer-sensitive unstable transcripts (DUTs). XUTs and DUTs are enriched for antisense lncRNAs, while CUTs are often bidirectional and actively translated. The cytoplasmic exonuclease, along with RNAi, dampens the expression of thousands of lncRNAs and mRNAs that become induced during meiosis. Antisense lncRNA expression mostly negatively correlates with sense mRNA expression in the physiological, but not the genetic conditions. Intergenic and bidirectional lncRNAs emerge from nucleosome-depleted regions, upstream of positioned nucleosomes. Our results highlight both similarities and differences to lncRNA regulation in budding yeast. This broad survey of the lncRNA repertoire and characteristics in S. pombe, and the interwoven regulatory pathways that target lncRNAs, provides a rich framework for their further functional analyses.
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Affiliation(s)
- Sophie R Atkinson
- Research Department of Genetics, Evolution and Environment and UCL Genetics Institute, University College London, London WC1E 6BT, United Kingdom
| | - Samuel Marguerat
- Research Department of Genetics, Evolution and Environment and UCL Genetics Institute, University College London, London WC1E 6BT, United Kingdom
- MRC London Institute of Medical Sciences (LMS), London W12 0NN, United Kingdom
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London W12 0NN, United Kingdom
| | - Danny A Bitton
- Research Department of Genetics, Evolution and Environment and UCL Genetics Institute, University College London, London WC1E 6BT, United Kingdom
| | - Maria Rodríguez-López
- Research Department of Genetics, Evolution and Environment and UCL Genetics Institute, University College London, London WC1E 6BT, United Kingdom
| | - Charalampos Rallis
- Research Department of Genetics, Evolution and Environment and UCL Genetics Institute, University College London, London WC1E 6BT, United Kingdom
| | - Jean-François Lemay
- Department of Biochemistry, Sherbrooke, Université de Sherbrooke, Quebec J1H 5N4, Canada
| | - Cristina Cotobal
- Research Department of Genetics, Evolution and Environment and UCL Genetics Institute, University College London, London WC1E 6BT, United Kingdom
| | - Michal Malecki
- Research Department of Genetics, Evolution and Environment and UCL Genetics Institute, University College London, London WC1E 6BT, United Kingdom
| | - Pawel Smialowski
- LMU Munich, Biomedical Center, 82152 Planegg-Martinsried near Munich, Germany
| | - Juan Mata
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Philipp Korber
- LMU Munich, Biomedical Center, 82152 Planegg-Martinsried near Munich, Germany
| | - François Bachand
- Department of Biochemistry, Sherbrooke, Université de Sherbrooke, Quebec J1H 5N4, Canada
| | - Jürg Bähler
- Research Department of Genetics, Evolution and Environment and UCL Genetics Institute, University College London, London WC1E 6BT, United Kingdom
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61
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Zhao Q, Yang W, Qin T, Huang Z. Moonlighting Phosphatase Activity of Klenow DNA Polymerase in the Presence of RNA. Biochemistry 2018; 57:5127-5135. [PMID: 30059615 DOI: 10.1021/acs.biochem.8b00688] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
RNA is a key player in the cellular central dogma, including RNA transcription and protein synthesis. However, it is unknown whether RNA can directly interfere with DNA synthesis. Recently, we have found in vitro that while binding to DNA polymerase nonspecifically, RNA can transform DNA polymerase to display a moonlighting activity, dNTP phosphatase, in turn interfering with DNA synthesis. This phosphatase activity removes the γ-phosphate from dNTPs (generating dNDPs) and subsequently removes the β-phosphate from the formed dNDPs (generating dNMPs), confirmed by the noncleavable α,β-CH2-dGTP and β,γ-CH2-dGTP analogues. We also found that dGTP is the best substrate for the phosphatase, and the dNTP phosphatase activity is sensitive to the reaction medium. In addition, we have revealed that RNA can tune the activity of closely related proteins and give rise to new catalytic functions with subtle differences. Moreover, we have demonstrated in vitro that at the lower dNTP level, this phosphatase can directly inhibit DNA synthesis by dNTP depletion, though the phosphatase activity is 690-fold slower than the polymerase activity. Our observation in vitro suggests a plausible strategy for RNA to directly interfere with DNA polymerase and DNA synthesis in vivo.
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Affiliation(s)
- Qianwei Zhao
- College of Life Sciences , Sichuan University , Chengdu , China
| | - Wen Yang
- College of Life Sciences , Sichuan University , Chengdu , China
| | - Tong Qin
- College of Life Sciences , Sichuan University , Chengdu , China
| | - Zhen Huang
- College of Life Sciences , Sichuan University , Chengdu , China.,Department of Chemistry , Georgia State University , Atlanta , Georgia 30303 , United States
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62
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Hong H, Chai HH, Nam K, Lim D, Lee KT, Do YJ, Cho CY, Nam JW. Non-Coding Transcriptome Maps across Twenty Tissues of the Korean Black Chicken, Yeonsan Ogye. Int J Mol Sci 2018; 19:ijms19082359. [PMID: 30103450 PMCID: PMC6121550 DOI: 10.3390/ijms19082359] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 07/15/2018] [Accepted: 08/08/2018] [Indexed: 12/14/2022] Open
Abstract
Yeonsan Ogye is a rare Korean domestic chicken breed whose entire body, including feathers and skin, has a unique black coloring. Although some protein-coding genes related to this unique feature have been examined, non-coding elements have not been widely investigated. Thus, we evaluated coding and non-coding transcriptome expression and identified long non-coding RNAs functionally linked to protein-coding genes in Ogye. High-throughput RNA sequencing and DNA methylation sequencing were performed to profile the expression of 14,264 Ogye protein-coding and 6900 long non-coding RNA (lncRNA) genes and detect DNA methylation in 20 different tissues of an individual Ogye. Approximately 75% of Ogye lncRNAs and 45% of protein-coding genes showed tissue-specific expression. For some genes, tissue-specific expression levels were inversely correlated with DNA methylation levels in their promoters. Approximately 39% of tissue-specific lncRNAs displayed functional associations with proximal or distal protein-coding genes. Heat shock transcription factor 2-associated lncRNAs appeared to be functionally linked to protein-coding genes specifically expressed in black skin tissues, more syntenically conserved in mammals, and differentially expressed in black relative to in white tissues. Pending experimental validation, our findings increase the understanding of how the non-coding genome regulates unique phenotypes and can be used for future genomic breeding of chickens.
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Affiliation(s)
- Hyosun Hong
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133791, Korea.
| | - Han-Ha Chai
- Department of Animal Biotechnology & Environment of National Institute of Animal Science, RDA, Wanju 55365, Korea.
- College of Pharmacy, Chonnam National University, Kwangju 61186, Korea.
| | - Kyoungwoo Nam
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133791, Korea.
| | - Dajeong Lim
- Department of Animal Biotechnology & Environment of National Institute of Animal Science, RDA, Wanju 55365, Korea.
| | - Kyung-Tai Lee
- Department of Animal Biotechnology & Environment of National Institute of Animal Science, RDA, Wanju 55365, Korea.
| | - Yoon Jung Do
- Department of Animal Biotechnology & Environment of National Institute of Animal Science, RDA, Wanju 55365, Korea.
| | - Chang-Yeon Cho
- Animal Genetic Resource Research Center of National Institute of Animal Science, RDA, Namwon 55717, Korea.
| | - Jin-Wu Nam
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133791, Korea.
- Research Institute for Convergence of Basic Sciences, Hanyang University, Seoul 133791, Korea.
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63
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A current view on long noncoding RNAs in yeast and filamentous fungi. Appl Microbiol Biotechnol 2018; 102:7319-7331. [PMID: 29974182 PMCID: PMC6097775 DOI: 10.1007/s00253-018-9187-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 02/06/2023]
Abstract
Long noncoding RNAs (lncRNAs) are crucial players in epigenetic regulation. They were initially discovered in human, yet they emerged as common factors involved in a number of central cellular processes in several eukaryotes. For example, in the past decade, research on lncRNAs in yeast has steadily increased. Several examples of lncRNAs were described in Saccharomyces cerevisiae and Schizosaccharomyces pombe. Also, screenings for lncRNAs in ascomycetes were performed and, just recently, the first full characterization of a lncRNA was performed in the filamentous fungus Trichoderma reesei. In this review, we provide a broad overview about currently known fugal lncRNAs. We make an attempt to categorize them according to their functional context, regulatory strategies or special properties. Moreover, the potential of lncRNAs as a biotechnological tool is discussed.
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64
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Wang R, Zou J, Meng J, Wang J. Integrative analysis of genome-wide lncRNA and mRNA expression in newly synthesized Brassica hexaploids. Ecol Evol 2018; 8:6034-6052. [PMID: 29988444 PMCID: PMC6024132 DOI: 10.1002/ece3.4152] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/29/2018] [Accepted: 04/09/2018] [Indexed: 01/02/2023] Open
Abstract
Polyploidization, as a significant evolution force, has been considered to facilitate plant diversity. The expression levels of lncRNAs and how they control the expression of protein-coding genes in allopolyploids remain largely unknown. In this study, lncRNA expression profiles were compared between Brassica hexaploid and its parents using a high-throughput sequencing approach. A total of 2,725, 1,672, and 2,810 lncRNAs were discovered in Brassica rapa, Brassica carinata, and Brassica hexaploid, respectively. It was also discovered that 725 lncRNAs were differentially expressed between Brassica hexaploid and its parents, and 379 lncRNAs were nonadditively expressed in this hexaploid. LncRNAs have multiple expression patterns between Brassica hexaploid and its parents and show paternal parent-biased expression. These lncRNAs were found to implement regulatory functions directly in the long-chain form, and acted as precursors or targets of miRNAs. According to the prediction of the targets of differentially expressed lncRNAs, 109 lncRNAs were annotated, and their target genes were involved in the metabolic process, pigmentation, reproduction, exposure to stimulus, biological regulation, and so on. Compared with the paternal parent, differentially expressed lncRNAs between Brassica hexaploid and its maternal parent participated in more regulation pathways. Additionally, 61 lncRNAs were identified as putative targets of known miRNAs, and 15 other lncRNAs worked as precursors of miRNAs. Some conservative motifs of lncRNAs from different groups were detected, which indicated that these motifs could be responsible for their regulatory roles. Our findings may provide a reference for the further study of the function and action mechanisms of lncRNAs during plant evolution.
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Affiliation(s)
- Ruihua Wang
- State Key Laboratory of Hybrid RiceDepartment of Plant ScienceCollege of Life SciencesWuhan UniversityWuhanChina
| | - Jun Zou
- National Key Laboratory of Crop Genetic ImprovementCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Jinling Meng
- National Key Laboratory of Crop Genetic ImprovementCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Jianbo Wang
- State Key Laboratory of Hybrid RiceDepartment of Plant ScienceCollege of Life SciencesWuhan UniversityWuhanChina
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Till P, Pucher ME, Mach RL, Mach-Aigner AR. A long noncoding RNA promotes cellulase expression in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:78. [PMID: 29588663 PMCID: PMC5865335 DOI: 10.1186/s13068-018-1081-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 03/14/2018] [Indexed: 05/31/2023]
Abstract
BACKGROUND Due to its capability to secrete large quantities of plant biomass degrading enzymes (PBDE), Trichoderma reesei is widely applied for industrial purposes. In nature, expression of PBDE is efficiently regulated in this fungus. Several factors involved in this regulatory network have been identified. However, most of them are transcription factors. Long noncoding RNAs (lncRNAs) emerged as common players acting on epigenetic or transcriptional regulation in several eukaryotic organisms. To date, no lncRNA has been described in filamentous fungi. RESULTS A lncRNA termed HAX1 was identified in T. reesei QM9414. In this study, it was characterized and evidence for its regulatory impact on cellulase expression was provided. Interestingly, different versions of HAX1 were identified in different strains (namely, QM6a, QM9414, and Rut-C30), varying in terms of RNA length. Remarkably, considerable longer variants of this lncRNA are present in hypercellulolytic strains compared to the wild-type strain QM6a. Based on these results, a correlation between RNA length and the functional impact of HAX1 on PBDE expression was supposed. This assumption was verified by overexpressing the most abundant HAX1 versions identified in QM6a, QM9414, and Rut-C30. Such HAX1 overexpression on the one hand was suitable for regaining the function in hax1 disruption strains, and on the other hand resulted in notably higher cellulase activities in QM6a, especially by the expression of longer HAX1 versions. CONCLUSION With HAX1, for the first time the regulatory role of a lncRNA in filamentous fungi was uncovered. Besides this, a new player involved in the complex regulation of PBDE expression in T. reesei was identified. Due to its enhancing effect on cellulase activity, HAX1 was shown to be not only interesting for basic research, but also a promising candidate for expanding the set of biotechnological tools for industrial application of T. reesei.
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Affiliation(s)
- Petra Till
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Marion E. Pucher
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Robert L. Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Astrid R. Mach-Aigner
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
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Moretto F, Wood NE, Kelly G, Doncic A, van Werven FJ. A regulatory circuit of two lncRNAs and a master regulator directs cell fate in yeast. Nat Commun 2018; 9:780. [PMID: 29472539 PMCID: PMC5823921 DOI: 10.1038/s41467-018-03213-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 01/24/2018] [Indexed: 12/27/2022] Open
Abstract
Transcription of long noncoding RNAs (lncRNAs) regulates local gene expression in eukaryotes. Many examples of how a single lncRNA controls the expression of an adjacent or nearby protein-coding gene have been described. Here we examine the regulation of a locus consisting of two contiguous lncRNAs and the master regulator for entry into yeast meiosis, IME1. We find that the cluster of two lncRNAs together with several transcription factors form a regulatory circuit by which IME1 controls its own promoter and thereby promotes its own expression. Inhibition or stimulation of this unusual feedback circuit affects timing and rate of IME1 accumulation, and hence the ability for cells to enter meiosis. Our data demonstrate that orchestrated transcription through two contiguous lncRNAs promotes local gene expression and determines a critical cell fate decision.
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Affiliation(s)
- Fabien Moretto
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - N Ezgi Wood
- Department of Cell Biology, UT Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Gavin Kelly
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Andreas Doncic
- Department of Cell Biology, UT Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX, 75390, USA
- Green Center for Systems Biology, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX, 75390, USA
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Kim S, Nguyen QB, Wolyniak MJ, Frechette G, Lehman CR, Fox BK, Sundstrom P. Release of transcriptional repression through the HCR promoter region confers uniform expression of HWP1 on surfaces of Candida albicans germ tubes. PLoS One 2018; 13:e0192260. [PMID: 29438403 PMCID: PMC5810986 DOI: 10.1371/journal.pone.0192260] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/19/2018] [Indexed: 12/31/2022] Open
Abstract
The mechanisms that fungi use to co-regulate subsets of genes specifically associated with morphogenic states represent a basic unsolved problem in fungal biology. Candida albicans is an important model of fungal differentiation both for rapid interconversion between yeast and hyphal growth forms and for white/opaque switching mechanisms. The Sundstrom lab is interested in mechanisms regulating hypha-specific expression of adhesin genes that are critical for C. albicans hyphal growth phenotypes and pathogenicity. Early studies on hypha-specific genes such as HWP1 and ALS3 reported 5’ intergenic regions that are larger than those typically found in an average promoter and are associated with hypha-specific expression. In the case of HWP1, activation and repression involves a 368 bp region, denoted the HWP1 control region (HCR), located 1410 bp upstream of its transcription start site. In previous work we showed that HCR confers developmental regulation to a heterologous ENO1 promoter, indicating that HCR by itself contains sufficient information to couple gene expression to morphology. Here we show that the activation and repression mediated by HCR are localized to distinct HCR regions that are targeted by the transcription factors Nrg1p and Efg1p. The finding that Efg1p mediates both repression via HCR under yeast morphological conditions and activation conditions positions Efg1p as playing a central role in coupling HWP1 expression to morphogenesis through the HCR region. These localization studies revealed that the 120 terminal base pairs of HCR confer Efg1p-dependent repressive activity in addition to the Nrg1p repressive activity mediated by DNA upstream of this subregion. The 120 terminal base pair subregion of HCR also contained an initiation site for an HWP1 transcript that is specific to yeast growth conditions (HCR-Y) and may function in the repression of downstream DNA. The detection of an HWP1 mRNA isoform specific to hyphal growth conditions (HWP1-H) showed that morphology-specific mRNA isoforms occur under both yeast and hyphal growth conditions. Similar results were found at the ALS3 locus. Taken together, these results, suggest that the long 5’ intergenic regions upstream of hypha-specific genes function in generating mRNA isoforms that are important for morphology-specific gene expression. Additional complexity in the HWP1 promoter involving HCR-independent activation was discovered by creating a strain lacking HCR that exhibited variable HWP1 expression during hyphal growth conditions. These results show that while HCR is important for ensuring uniform HWP1 expression in cell populations, HCR independent expression also exists. Overall, these results elucidate HCR-dependent mechanisms for coupling HWP1-dependent gene expression to morphology uniformly in cell populations and prompt the hypothesis that mRNA isoforms may play a role in coupling gene expression to morphology in C. albicans.
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Affiliation(s)
- Samin Kim
- Department of Microbiology and Immunology, Microbiology and Molecular Pathogenesis Program, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Quoc Bao Nguyen
- Department of Microbiology and Immunology, Microbiology and Molecular Pathogenesis Program, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Michael J. Wolyniak
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, Virginia, United States of America
| | - Gregory Frechette
- Department of Microbiology and Immunology, Microbiology and Molecular Pathogenesis Program, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Christian R. Lehman
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, Virginia, United States of America
| | - Brandon K. Fox
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, Virginia, United States of America
| | - Paula Sundstrom
- Department of Microbiology and Immunology, Microbiology and Molecular Pathogenesis Program, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- * E-mail:
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Ooka M, Abe T, Cho K, Koike K, Takeda S, Hirota K. Chromatin remodeler ALC1 prevents replication-fork collapse by slowing fork progression. PLoS One 2018; 13:e0192421. [PMID: 29408941 PMCID: PMC5800655 DOI: 10.1371/journal.pone.0192421] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/23/2018] [Indexed: 11/18/2022] Open
Abstract
ALC1 (amplified in liver cancer 1), an SNF2 superfamily chromatin-remodeling factor also known as CHD1L (chromodomain helicase/ATPase DNA binding protein 1-like), is implicated in base-excision repair, where PARP (Poly(ADP-ribose) polymerase) mediated Poly(ADP-ribose) signaling facilitates the recruitment of this protein to damage sites. We here demonstrate the critical role played by ALC1 in the regulation of replication-fork progression in cleaved template strands. To analyze the role played by ALC1 as well as its functional relationship with PARP1, we generated ALC1-/-, PARP1-/-, and ALC1-/-/PARP1-/- cells from chicken DT40 cells. We then exposed these cells to camptothecin (CPT), a topoisomerase I poison that generates single-strand breaks and causes the collapse of replication forks. The ALC1-/- and PARP1-/- cells exhibited both higher sensitivity to CPT and an increased number of chromosome aberrations, compared with wild-type cells. Moreover, phenotypes were very similar across all three mutants, indicating that the role played by ALC1 in CPT tolerance is dependent upon the PARP pathway. Remarkably, inactivation of ALC1 resulted in a failure to slow replication-fork progression after CPT exposure, indicating that ALC1 regulates replication-fork progression at DNA-damage sites. We disrupted ATPase activity by inserting the E165Q mutation into the ALC1 gene, and found that the resulting ALC1-/E165Q cells displayed a CPT sensitivity indistinguishable from that of the null-mutant cells. This observation suggests that ALC1 contributes to cellular tolerance to CPT, possibly as a chromatin remodeler. This idea is supported by the fact that CPT exposure induced chromatin relaxation in the vicinity of newly synthesized DNA in wild-type but not in ALC1-/- cells. This implies a previously unappreciated role for ALC1 in DNA replication, in which ALC1 may regulate replication-fork slowing at CPT-induced DNA-damage sites.
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Affiliation(s)
- Masato Ooka
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1–1 Minami-osawa, Hachioji, Tokyo, Japan
| | - Takuya Abe
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1–1 Minami-osawa, Hachioji, Tokyo, Japan
| | - Kosai Cho
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
| | - Kaoru Koike
- Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- * E-mail: (KH); (ST)
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1–1 Minami-osawa, Hachioji, Tokyo, Japan
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- * E-mail: (KH); (ST)
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When Long Noncoding RNAs Meet Genome Editing in Pluripotent Stem Cells. Stem Cells Int 2017; 2017:3250624. [PMID: 29333164 PMCID: PMC5733163 DOI: 10.1155/2017/3250624] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/25/2017] [Indexed: 11/18/2022] Open
Abstract
Most of the human genome can be transcribed into RNAs, but only a minority of these regions produce protein-coding mRNAs whereas the remaining regions are transcribed into noncoding RNAs. Long noncoding RNAs (lncRNAs) were known for their influential regulatory roles in multiple biological processes such as imprinting, dosage compensation, transcriptional regulation, and splicing. The physiological functions of protein-coding genes have been extensively characterized through genome editing in pluripotent stem cells (PSCs) in the past 30 years; however, the study of lncRNAs with genome editing technologies only came into attentions in recent years. Here, we summarize recent advancements in dissecting the roles of lncRNAs with genome editing technologies in PSCs and highlight potential genome editing tools useful for examining the functions of lncRNAs in PSCs.
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Tsuda M, Cho K, Ooka M, Shimizu N, Watanabe R, Yasui A, Nakazawa Y, Ogi T, Harada H, Agama K, Nakamura J, Asada R, Fujiike H, Sakuma T, Yamamoto T, Murai J, Hiraoka M, Koike K, Pommier Y, Takeda S, Hirota K. ALC1/CHD1L, a chromatin-remodeling enzyme, is required for efficient base excision repair. PLoS One 2017; 12:e0188320. [PMID: 29149203 PMCID: PMC5693467 DOI: 10.1371/journal.pone.0188320] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 11/03/2017] [Indexed: 11/18/2022] Open
Abstract
ALC1/CHD1L is a member of the SNF2 superfamily of ATPases carrying a macrodomain that binds poly(ADP-ribose). Poly(ADP-ribose) polymerase (PARP) 1 and 2 synthesize poly(ADP-ribose) at DNA-strand cleavage sites, promoting base excision repair (BER). Although depletion of ALC1 causes increased sensitivity to various DNA-damaging agents (H2O2, UV, and phleomycin), the role played by ALC1 in BER has not yet been established. To explore this role, as well as the role of ALC1’s ATPase activity in BER, we disrupted the ALC1 gene and inserted the ATPase-dead (E165Q) mutation into the ALC1 gene in chicken DT40 cells, which do not express PARP2. The resulting ALC1-/- and ALC1-/E165Q cells displayed an indistinguishable hypersensitivity to methylmethane sulfonate (MMS), an alkylating agent, and to H2O2, indicating that ATPase plays an essential role in the DNA-damage response. PARP1-/- and ALC1-/-/PARP1-/- cells exhibited a very similar sensitivity to MMS, suggesting that ALC1 and PARP1 collaborate in BER. Following pulse-exposure to H2O2, PARP1-/- and ALC1-/-/PARP1-/- cells showed similarly delayed kinetics in the repair of single-strand breaks, which arise as BER intermediates. To ascertain ALC1’s role in BER in mammalian cells, we disrupted the ALC1 gene in human TK6 cells. Following exposure to MMS and to H2O2, the ALC1-/- TK6 cell line showed a delay in single-strand-break repair. We therefore conclude that ALC1 plays a role in BER. Following exposure to H2O2,ALC1-/- cells showed compromised chromatin relaxation. We thus propose that ALC1 is a unique BER factor that functions in a chromatin context, most likely as a chromatin-remodeling enzyme.
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Affiliation(s)
- Masataka Tsuda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Kosai Cho
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
| | - Masato Ooka
- Department of Chemistry, Tokyo Metropolitan University, Minami-Osawa, Hachioji- shi, Tokyo, Japan
| | - Naoto Shimizu
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Reiko Watanabe
- Division of Dynamic Proteome, Institute of Development, Aging and Cancer, Tohoku University, Seiryomachi 4–1, Aobaku, Sendai, Japan
| | - Akira Yasui
- Division of Dynamic Proteome, Institute of Development, Aging and Cancer, Tohoku University, Seiryomachi 4–1, Aobaku, Sendai, Japan
| | - Yuka Nakazawa
- Department of Genome Repair, Atomic Bomb Disease Institute, Nagasaki University Sakamoto, Nagasaki, Japan
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan
| | - Tomoo Ogi
- Department of Genome Repair, Atomic Bomb Disease Institute, Nagasaki University Sakamoto, Nagasaki, Japan
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan
| | - Hiroshi Harada
- Laboratory of Cancer Cell Biology, Radiation Biology Center, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Keli Agama
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Jun Nakamura
- Department of Environmental Sciences and Engineering, University of North Carolina Chapel Hill, North Carolina, United States of America
| | - Ryuta Asada
- Department of Chemistry, Tokyo Metropolitan University, Minami-Osawa, Hachioji- shi, Tokyo, Japan
| | - Haruna Fujiike
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Tetsushi Sakuma
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Hiroshima, Japan
| | - Takashi Yamamoto
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Hiroshima, Japan
| | - Junko Murai
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Masahiro Hiraoka
- Department of Radiation Oncology, Japanese Red Cross Society Wakayama Medical Center, Komatsubara-Dori, Wakayama, Japan
| | - Kaoru Koike
- Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
| | - Yves Pommier
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- * E-mail: (KH); (ST)
| | - Kouji Hirota
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
- Department of Chemistry, Tokyo Metropolitan University, Minami-Osawa, Hachioji- shi, Tokyo, Japan
- * E-mail: (KH); (ST)
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Genome-wide identification of miRNAs and lncRNAs in Cajanus cajan. BMC Genomics 2017; 18:878. [PMID: 29141604 PMCID: PMC5688659 DOI: 10.1186/s12864-017-4232-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 10/23/2017] [Indexed: 01/24/2023] Open
Abstract
Background Non-coding RNAs (ncRNAs) are important players in the post transcriptional regulation of gene expression (PTGR). On one hand, microRNAs (miRNAs) are an abundant class of small ncRNAs (~22nt long) that negatively regulate gene expression at the levels of messenger RNAs stability and translation inhibition, on the other hand, long ncRNAs (lncRNAs) are a large and diverse class of transcribed non-protein coding RNA molecules (> 200nt) that play both up-regulatory as well as down-regulatory roles at the transcriptional level. Cajanus cajan, a leguminosae pulse crop grown in tropical and subtropical areas of the world, is a source of high value protein to vegetarians or very poor populations globally. Hence, genome-wide identification of miRNAs and lncRNAs in C. cajan is extremely important to understand their role in PTGR with a possible implication to generate improve variety of crops. Results We have identified 616 mature miRNAs in C. cajan belonging to 118 families, of which 578 are novel and not reported in MirBase21. A total of 1373 target sequences were identified for 180 miRNAs. Of these, 298 targets were characterized at the protein level. Besides, we have also predicted 3919 lncRNAs. Additionally, we have identified 87 of the predicted lncRNAs to be targeted by 66 miRNAs. Conclusions miRNA and lncRNAs in plants are known to control a variety of traits including yield, quality and stress tolerance. Owing to its agricultural importance and medicinal value, the identified miRNA, lncRNA and their targets in C. cajan may be useful for genome editing to improve better quality crop. A thorough understanding of ncRNA-based cellular regulatory networks will aid in the improvement of C. cajan agricultural traits. Electronic supplementary material The online version of this article (10.1186/s12864-017-4232-2) contains supplementary material, which is available to authorized users.
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Mehra M, Chauhan R. Long Noncoding RNAs as a Key Player in Hepatocellular Carcinoma. BIOMARKERS IN CANCER 2017; 9:1179299X17737301. [PMID: 29147078 PMCID: PMC5673005 DOI: 10.1177/1179299x17737301] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Indexed: 12/16/2022]
Abstract
Hepatocellular carcinoma (HCC) is a major malignancy in the liver and has emerged as one of the main cancers in the world with a high mortality rate. However, the molecular mechanisms of HCC are still poorly understood. Long noncoding RNAs (lncRNAs) have recently come to the forefront as functional non-protein-coding RNAs that are involved in a variety of cellular processes ranging from maintaining the structural integrity of chromosomes to gene expression regulation in a spatiotemporal manner. Many recent studies have reported the involvement of lncRNAs in HCC which has led to a better understanding of the underlying molecular mechanisms operating in HCC. Long noncoding RNAs have been shown to regulate development and progression of HCC, and thus, lncRNAs have both diagnostic and therapeutic potentials. In this review, we present an overview of the lncRNAs involved in different stages of HCC and their potential in clinical applications which have been studied so far.
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Affiliation(s)
- Mrigaya Mehra
- Studio of Computational Biology & Bioinformatics, Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT), Palampur, India
- Academy of Scientific & Innovative Research, Chennai, India
| | - Ranjit Chauhan
- Department of Hepatology, Loyola University Chicago, Chicago, IL, USA
- Molecular Virology and Hepatology Research Group, Division of BioMedical Sciences, Health Sciences Center, Memorial University, St John’s, Newfoundland and Labrador, Canada
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Asada R, Umeda M, Adachi A, Senmatsu S, Abe T, Iwasaki H, Ohta K, Hoffman CS, Hirota K. Recruitment and delivery of the fission yeast Rst2 transcription factor via a local genome structure counteracts repression by Tup1-family corepressors. Nucleic Acids Res 2017; 45:9361-9371. [PMID: 28934464 PMCID: PMC5766161 DOI: 10.1093/nar/gkx555] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 06/14/2017] [Indexed: 12/12/2022] Open
Abstract
Transcription factors (TFs) determine the transcription activity of target genes and play a central role in controlling the transcription in response to various environmental stresses. Three dimensional genome structures such as local loops play a fundamental role in the regulation of transcription, although the link between such structures and the regulation of TF binding to cis-regulatory elements remains to be elucidated. Here, we show that during transcriptional activation of the fission yeast fbp1 gene, binding of Rst2 (a critical C2H2 zinc-finger TF) is mediated by a local loop structure. During fbp1 activation, Rst2 is first recruited to upstream-activating sequence 1 (UAS1), then it subsequently binds to UAS2 (a critical cis-regulatory site located approximately 600 base pairs downstream of UAS1) through a loop structure that brings UAS1 and UAS2 into spatially close proximity. Tup11/12 (the Tup-family corepressors) suppress direct binding of Rst2 to UAS2, but this suppression is counteracted by the recruitment of Rst2 at UAS1 and following delivery to UAS2 through a loop structure. These data demonstrate a previously unappreciated mechanism for the recruitment and expansion of TF-DNA interactions within a promoter mediated by local three-dimensional genome structures and for timely TF-binding via counteractive regulation by the Tup-family corepressors.
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Affiliation(s)
- Ryuta Asada
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Miki Umeda
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Akira Adachi
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Satoshi Senmatsu
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Takuya Abe
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Hiroshi Iwasaki
- Cell Biology Unit, Institute of Innovative Research, Tokyo Institute of Technology M6-11, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Kunihiro Ohta
- Department of Life Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan.,Universal Biology Institute, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | | | - Kouji Hirota
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
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Abstract
Eukaryotic genomes are rich in transcription units encoding "long noncoding RNAs" (lncRNAs). The purpose of all this transcription is unclear since most lncRNAs are quickly targeted for destruction during synthesis or shortly thereafter. As debates continue over the functional significance of many specific lncRNAs, support grows for the notion that the act of transcription rather than the RNA product itself is functionally important in many cases. Indeed, this alternative mechanism might better explain how low-abundance lncRNAs transcribed from noncoding DNA function in organisms. Here, we highlight some of the recently emerging features that distinguish coding from noncoding transcription and discuss how these differences might have important implications for the functional consequences of noncoding transcription.
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Functions of long non-coding RNAs in human disease and their conservation in Drosophila development. Biochem Soc Trans 2017; 45:895-904. [PMID: 28673935 DOI: 10.1042/bst20160428] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/18/2017] [Accepted: 05/31/2017] [Indexed: 02/06/2023]
Abstract
Genomic analysis has found that the transcriptome in both humans and Drosophila melanogaster features large numbers of long non-coding RNA transcripts (lncRNAs). This recently discovered class of RNAs regulates gene expression in diverse ways and has been involved in a large variety of important biological functions. Importantly, an increasing number of lncRNAs have also been associated with a range of human diseases, including cancer. Comparative analyses of their functions among these organisms suggest that some of their modes of action appear to be conserved. This highlights the importance of model organisms such as Drosophila, which shares many gene regulatory networks with humans, in understanding lncRNA function and its possible impact in human health. This review discusses some known functions and mechanisms of action of lncRNAs and their implication in human diseases, together with their functional conservation and relevance in Drosophila development.
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Adachi A, Senmatsu S, Asada R, Abe T, Hoffman CS, Ohta K, Hirota K. Interplay between chromatin modulators and histone acetylation regulates the formation of accessible chromatin in the upstream regulatory region of fission yeast fbp1. Genes Genet Syst 2017; 92:267-276. [PMID: 28674280 DOI: 10.1266/ggs.17-00018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Numerous noncoding RNA transcripts are detected in eukaryotic cells. Noncoding RNAs transcribed across gene promoters are involved in the regulation of mRNA transcription via chromatin modulation. This function of noncoding RNA transcription was first demonstrated for the fission yeast fbp1 gene, where a cascade of noncoding RNA transcription events induces chromatin remodeling to facilitate transcription factor binding. We recently demonstrated that the noncoding RNAs from the fbp1 upstream region facilitate binding of the transcription activator Atf1 and thereby promote histone acetylation. Histone acetylation by histone acetyl transferases (HATs) and ATP-dependent chromatin remodelers (ADCRs) are implicated in chromatin remodeling, but the interplay between HATs and ADCRs in this process has not been fully elucidated. Here, we examine the roles played by two distinct ADCRs, Snf22 and Hrp3, and by the HAT Gcn5 in the transcriptional activation of fbp1. Snf22 and Hrp3 redundantly promote disassembly of chromatin in the fbp1 upstream region. Gcn5 critically contributes to nucleosome eviction in the absence of either Snf22 or Hrp3, presumably by recruiting Hrp3 in snf22∆ cells and Snf22 in hrp3∆ cells. Conversely, Gcn5-dependent histone H3 acetylation is impaired in snf22∆/hrp3∆ cells, suggesting that both redundant ADCRs induce recruitment of Gcn5 to the chromatin array in the fbp1 upstream region. These results reveal a previously unappreciated interplay between ADCRs and histone acetylation in which histone acetylation facilitates recruitment of ADCRs, while ADCRs are required for histone acetylation.
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Affiliation(s)
- Akira Adachi
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University
| | - Satoshi Senmatsu
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University
| | - Ryuta Asada
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University
| | - Takuya Abe
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University
| | | | - Kunihiro Ohta
- Department of Life Sciences, The University of Tokyo
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University
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77
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Luo J, Liu L, Venkateswaran S, Song Q, Zhou X. RPI-Bind: a structure-based method for accurate identification of RNA-protein binding sites. Sci Rep 2017; 7:614. [PMID: 28377624 PMCID: PMC5429624 DOI: 10.1038/s41598-017-00795-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 03/13/2017] [Indexed: 01/11/2023] Open
Abstract
RNA and protein interactions play crucial roles in multiple biological processes, while these interactions are significantly influenced by the structures and sequences of protein and RNA molecules. In this study, we first performed an analysis of RNA-protein interacting complexes, and identified interface properties of sequences and structures, which reveal the diverse nature of the binding sites. With the observations, we built a three-step prediction model, namely RPI-Bind, for the identification of RNA-protein binding regions using the sequences and structures of both proteins and RNAs. The three steps include 1) the prediction of RNA binding regions on protein, 2) the prediction of protein binding regions on RNA, and 3) the prediction of interacting regions on both RNA and protein simultaneously, with the results from steps 1) and 2). Compared with existing methods, most of which employ only sequences, our model significantly improves the prediction accuracy at each of the three steps. Especially, our model outperforms the catRAPID by >20% at the 3rd step. All of these results indicate the importance of structures in RNA-protein interactions, and suggest that the RPI-Bind model is a powerful theoretical framework for studying RNA-protein interactions.
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Affiliation(s)
- Jiesi Luo
- Center for Bioinformatics and Systems Biology and Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Liang Liu
- Center for Bioinformatics and Systems Biology and Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Suresh Venkateswaran
- Center for Bioinformatics and Systems Biology and Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Qianqian Song
- Center for Bioinformatics and Systems Biology and Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Xiaobo Zhou
- Center for Bioinformatics and Systems Biology and Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA.
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78
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Jiang H, Good DJ. A molecular conundrum involving hypothalamic responses to and roles of long non-coding RNAs following food deprivation. Mol Cell Endocrinol 2016; 438:52-60. [PMID: 27555291 PMCID: PMC5116272 DOI: 10.1016/j.mce.2016.08.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 08/16/2016] [Accepted: 08/16/2016] [Indexed: 12/15/2022]
Abstract
Long non-coding RNAs (lncRNAs) are one of most poorly understood RNA classes in the mammalian transcriptome. However, they are emerging as important players in transcriptional regulation, especially within the complexity of the nervous system. This review summarizes the known information about lncRNAs, and their roles in endocrine processes, as well as the lesser-known information about lncRNAs in the brain, and in the neuroendocrine hypothalamus. A "call-to-action" is presented for researchers to use archival transcriptome data to characterize differentially expressed lncRNA species within the hypothalamus. In accordance, we analyze for differential-expression of lncRNA between normal mice and mice with a targeted deletion of the nescient helix-loop-helix 2 gene, and between C57Bl/6 and 129Sv/J mice. Finally, strategies and approaches for researchers to analyze their own datasets or those on the NCBI GEO datasets repository are provided, in hopes that future studies will reveal many new roles for lncRNAs in hypothalamic physiological responses, solving this so-called "molecular conundrum" once and for all.
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Affiliation(s)
- Hao Jiang
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Deborah J Good
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA, 24061, USA.
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79
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Takemata N, Ohta K. Role of non-coding RNA transcription around gene regulatory elements in transcription factor recruitment. RNA Biol 2016; 14:1-5. [PMID: 27763805 PMCID: PMC5270525 DOI: 10.1080/15476286.2016.1248020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Eukaryotic cells produce a variety of non-coding RNAs (ncRNAs), many of which have been shown to play pivotal roles in biological processes such as differentiation, maintenance of pluripotency of stem cells, and cellular response to various stresses. Genome-wide analyses have revealed that many ncRNAs are transcribed around regulatory DNA elements located proximal or distal to gene promoters, but their biological functions are largely unknown. Recently, it has been demonstrated in yeast and mouse that ncRNA transcription around gene promoters and enhancers facilitates DNA binding of transcription factors to their target sites. These results suggest universal roles of promoter/enhancer-associated ncRNAs in the recruitment of transcription factors to their binding sites.
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Affiliation(s)
| | - Kunihiro Ohta
- a Department of Life Sciences , The University of Tokyo , Japan.,b Department of Biological Sciences , The University of Tokyo , Japan
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80
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Miki A, Galipon J, Sawai S, Inada T, Ohta K. RNA decay systems enhance reciprocal switching of sense and antisense transcripts in response to glucose starvation. Genes Cells 2016; 21:1276-1289. [PMID: 27723196 DOI: 10.1111/gtc.12443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 09/13/2016] [Indexed: 02/03/2023]
Abstract
Antisense RNA has emerged as a crucial regulator of opposite-strand protein-coding genes in the long noncoding RNA (lncRNA) category, but little is known about their dynamics and decay process in the context of a stress response. Antisense transcripts from the fission yeast fbp1 locus (fbp1-as) are expressed in glucose-rich conditions and anticorrelated with transcription of metabolic stress-induced lncRNA (mlonRNA) and mRNA on the sense strand during glucose starvation. Here, we investigate the localization and decay of antisense RNAs at fbp1 and other loci, and propose a model to explain the rapid switch between antisense and sense mlonRNA/mRNA transcription triggered by glucose starvation. We show that fbp1-as shares many features with mRNAs, such as a 5'-cap and poly(A)-tail, and that its decay partially depends upon Rrp6, a cofactor of the nuclear exosome complex involved in 3'-5' degradation of RNA. Fluorescence in situ hybridization and polysome fractionation show that the majority of remaining fbp1-as localizes to the cytoplasm and binds to polyribosomes in glucose-rich conditions. Furthermore, fbp1-as and antisense RNA at other stress-responsive loci are promptly degraded via the cotranslational nonsense-mediated decay (NMD) pathway. These results suggest NMD may potentiate the swift disappearance of antisense RNAs in response to cellular stress.
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Affiliation(s)
- Atsuko Miki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan
| | - Josephine Galipon
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0035, Japan
| | - Satoshi Sawai
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan
| | - Toshifumi Inada
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, 980-8578, Japan
| | - Kunihiro Ohta
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan.,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan
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81
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Qu J, Zhao M, Hsiang T, Feng X, Zhang J, Huang C. Identification and Characterization of Small Noncoding RNAs in Genome Sequences of the Edible Fungus Pleurotus ostreatus. BIOMED RESEARCH INTERNATIONAL 2016; 2016:2503023. [PMID: 27703969 PMCID: PMC5040776 DOI: 10.1155/2016/2503023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/21/2016] [Accepted: 08/24/2016] [Indexed: 12/31/2022]
Abstract
Noncoding RNAs (ncRNAs) have been identified in many fungi. However, no genome-scale identification of ncRNAs has been inventoried for basidiomycetes. In this research, we detected 254 small noncoding RNAs (sncRNAs) in a genome assembly of an isolate (CCEF00389) of Pleurotus ostreatus, which is a widely cultivated edible basidiomycetous fungus worldwide. The identified sncRNAs include snRNAs, snoRNAs, tRNAs, and miRNAs. SnRNA U1 was not found in CCEF00389 genome assembly and some other basidiomycetous genomes by BLASTn. This implies that if snRNA U1 of basidiomycetes exists, it has a sequence that varies significantly from other organisms. By analyzing the distribution of sncRNA loci, we found that snRNAs and most tRNAs (88.6%) were located in pseudo-UTR regions, while miRNAs are commonly found in introns. To analyze the evolutionary conservation of the sncRNAs in P. ostreatus, we aligned all 254 sncRNAs to the genome assemblies of some other Agaricomycotina fungi. The results suggest that most sncRNAs (77.56%) were highly conserved in P. ostreatus, and 20% were conserved in Agaricomycotina fungi. These findings indicate that most sncRNAs of P. ostreatus were not conserved across Agaricomycotina fungi.
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Affiliation(s)
- Jibin Qu
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Microbial Resources, Ministry of Agriculture, Beijing, China
| | - Mengran Zhao
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Microbial Resources, Ministry of Agriculture, Beijing, China
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - Xiaoxing Feng
- College of Computer Science and Software Engineering, Shenzhen University, Shenzhen, Guangdong, China
- Shenzhen Micro & Nano Research Institute of IC and System Applications, Shenzhen, Guangdong, China
| | - Jinxia Zhang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Microbial Resources, Ministry of Agriculture, Beijing, China
| | - Chenyang Huang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Microbial Resources, Ministry of Agriculture, Beijing, China
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82
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Ard R, Allshire RC. Transcription-coupled changes to chromatin underpin gene silencing by transcriptional interference. Nucleic Acids Res 2016; 44:10619-10630. [PMID: 27613421 PMCID: PMC5159543 DOI: 10.1093/nar/gkw801] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/17/2016] [Accepted: 08/31/2016] [Indexed: 02/07/2023] Open
Abstract
Long non-coding RNA (lncRNA) transcription into a downstream promoter frequently results in transcriptional interference. However, the mechanism of this repression is not fully understood. We recently showed that drug tolerance in fission yeast Schizosaccharomyces pombe is controlled by lncRNA transcription upstream of the tgp1+ permease gene. Here we demonstrate that transcriptional interference of tgp1+ involves several transcription-coupled chromatin changes mediated by conserved elongation factors Set2, Clr6CII, Spt6 and FACT. These factors are known to travel with RNAPII and establish repressive chromatin in order to limit aberrant transcription initiation from cryptic promoters present in gene bodies. We therefore conclude that conserved RNAPII-associated mechanisms exist to both suppress intragenic cryptic promoters during genic transcription and to repress gene promoters by transcriptional interference. Our analyses also demonstrate that key mechanistic features of transcriptional interference are shared between S. pombe and the highly divergent budding yeast Saccharomyces cerevisiae. Thus, transcriptional interference is an ancient, conserved mechanism for tightly controlling gene expression. Our mechanistic insights allowed us to predict and validate a second example of transcriptional interference involving the S. pombe pho1+ gene. Given that eukaryotic genomes are pervasively transcribed, transcriptional interference likely represents a more general feature of gene regulation than is currently appreciated.
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Affiliation(s)
- Ryan Ard
- Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Robin C Allshire
- Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
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83
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Evidence for Regulation of ECM3 Expression by Methylation of Histone H3 Lysine 4 and Intergenic Transcription in Saccharomyces cerevisiae. G3-GENES GENOMES GENETICS 2016; 6:2971-81. [PMID: 27449519 PMCID: PMC5015954 DOI: 10.1534/g3.116.033118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Transcription of nonprotein-coding DNA is widespread in eukaryotes and plays important regulatory roles for many genes, including genes that are misregulated in cancer cells. Its pervasiveness presents the potential for a wealth of diverse regulatory roles for noncoding transcription. We previously showed that the act of transcribing noncoding DNA (ncDNA) across the promoter of the protein-coding SER3 gene in Saccharomyces cerevisiae positions nucleosomes over the upstream activating sequences, leading to strong repression of SER3 transcription. To explore the possibility of other regulatory roles for ncDNA transcription, we selected six candidate S. cerevisiae genes that express ncRNAs over their promoters and analyzed the regulation of one of these genes, ECM3, in detail. Because noncoding transcription can lead to changes in the local chromatin landscape that impinge on the expression of nearby coding genes, we surveyed the effects of various chromatin regulators on the expression of ECM3. These analyses identified roles for the Paf1 complex in positively regulating ECM3 transcription through methylation of histone H3 at lysine 4 (K4) and for Paf1 in controlling the pattern of intergenic transcription at this locus. By deleting a putative promoter for the noncoding transcription unit that lies upstream of ECM3, we provide evidence for a positive correlation between intergenic transcription and ECM3 expression. Our results are consistent with a model in which cotranscriptional methylation of histone H3 K4, mediated by the Paf1 complex and noncoding transcription, leads to activation of ECM3 transcription.
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84
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Signal B, Gloss BS, Dinger ME. Computational Approaches for Functional Prediction and Characterisation of Long Noncoding RNAs. Trends Genet 2016; 32:620-637. [PMID: 27592414 DOI: 10.1016/j.tig.2016.08.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 02/09/2023]
Abstract
Although a considerable portion of eukaryotic genomes is transcribed as long noncoding RNAs (lncRNAs), the vast majority are functionally uncharacterised. The rapidly expanding catalogue of mechanistically investigated lncRNAs has provided evidence for distinct functional subclasses, which are now ripe for exploitation as a general model to predict functions for uncharacterised lncRNAs. By utilising publicly-available genome-wide datasets and computational methods, we present several developed and emerging in silico approaches to characterise and predict the functions of lncRNAs. We propose that the application of these techniques provides valuable functional and mechanistic insight into lncRNAs, and is a crucial step for informing subsequent functional studies.
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Affiliation(s)
- Bethany Signal
- Garvan Institute of Medical Research, Sydney, Australia; St Vincent's Clinical School, University of New South Wales, Sydney, Australia
| | - Brian S Gloss
- Garvan Institute of Medical Research, Sydney, Australia; St Vincent's Clinical School, University of New South Wales, Sydney, Australia
| | - Marcel E Dinger
- Garvan Institute of Medical Research, Sydney, Australia; St Vincent's Clinical School, University of New South Wales, Sydney, Australia.
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85
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Goenka A, Sengupta S, Pandey R, Parihar R, Mohanta GC, Mukerji M, Ganesh S. Human satellite-III non-coding RNAs modulate heat-shock-induced transcriptional repression. J Cell Sci 2016; 129:3541-3552. [PMID: 27528402 DOI: 10.1242/jcs.189803] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 08/10/2016] [Indexed: 12/31/2022] Open
Abstract
The heat shock response is a conserved defense mechanism that protects cells from physiological stress, including thermal stress. Besides the activation of heat-shock-protein genes, the heat shock response is also known to bring about global suppression of transcription; however, the mechanism by which this occurs is poorly understood. One of the intriguing aspects of the heat shock response in human cells is the transcription of satellite-III (Sat3) long non-coding RNAs and their association with nuclear stress bodies (nSBs) of unknown function. Besides association with the Sat3 transcript, the nSBs are also known to recruit the transcription factors HSF1 and CREBBP, and several RNA-binding proteins, including the splicing factor SRSF1. We demonstrate here that the recruitment of CREBBP and SRSF1 to nSBs is Sat3-dependent, and that loss of Sat3 transcripts relieves the heat-shock-induced transcriptional repression of a few target genes. Conversely, forced expression of Sat3 transcripts results in the formation of nSBs and transcriptional repression even without a heat shock. Our results thus provide a novel insight into the regulatory role for the Sat3 transcripts in heat-shock-dependent transcriptional repression.
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Affiliation(s)
- Anshika Goenka
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Sonali Sengupta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Rajesh Pandey
- CSIR Ayurgenomics Unit - TRISUTRA, CSIR - Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Rashmi Parihar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Girish Chandra Mohanta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Mitali Mukerji
- CSIR Ayurgenomics Unit - TRISUTRA, CSIR - Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Subramaniam Ganesh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
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86
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Novel drought-responsive regulatory coding and non-coding transcripts from Oryza Sativa L. Genes Genomics 2016. [DOI: 10.1007/s13258-016-0439-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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87
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Qin D, Xu C. Study strategies for long non-coding RNAs and their roles in regulating gene expression. Cell Mol Biol Lett 2016. [PMID: 26204411 DOI: 10.1515/cmble-2015-0021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) have attracted considerable attention recently due to their involvement in numerous key cellular processes and in the development of various disorders. New high-throughput methods enable their study on a genome-wide scale. Numerous lncRNAs have been identified and characterized as important members of the biological regulatory network, with significant roles in regulating gene expression at the epigenetic, transcriptional and post-transcriptional levels. This paper summarizes the diverse mechanisms of action of these lncRNAs and looks at the study strategies in this field. A major challenge in future study is to establish more effective bioinformatics and experimental methods to explore the functions, detailed mechanisms of action and structures deciding the functional diversity of lncRNAs, since the vast majority remain unresolved.
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88
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Takemata N, Oda A, Yamada T, Galipon J, Miyoshi T, Suzuki Y, Sugano S, Hoffman CS, Hirota K, Ohta K. Local potentiation of stress-responsive genes by upstream noncoding transcription. Nucleic Acids Res 2016; 44:5174-89. [PMID: 26945040 PMCID: PMC4914089 DOI: 10.1093/nar/gkw142] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 02/25/2016] [Indexed: 02/06/2023] Open
Abstract
It has been postulated that a myriad of long noncoding RNAs (lncRNAs) contribute to gene regulation. In fission yeast, glucose starvation triggers lncRNA transcription across promoter regions of stress-responsive genes including fbp1 (fructose-1,6-bisphosphatase1). At the fbp1 promoter, this transcription promotes chromatin remodeling and fbp1 mRNA expression. Here, we demonstrate that such upstream noncoding transcription facilitates promoter association of the stress-responsive transcriptional activator Atf1 at the sites of transcription, leading to activation of the downstream stress genes. Genome-wide analyses revealed that ∼50 Atf1-binding sites show marked decrease in Atf1 occupancy when cells are treated with a transcription inhibitor. Most of these transcription-enhanced Atf1-binding sites are associated with stress-dependent induction of the adjacent mRNAs or lncRNAs, as observed in fbp1. These Atf1-binding sites exhibit low Atf1 occupancy and high histone density in glucose-rich conditions, and undergo dramatic changes in chromatin status after glucose depletion: enhanced Atf1 binding, histone eviction, and histone H3 acetylation. We also found that upstream transcripts bind to the Groucho-Tup1 type transcriptional corepressors Tup11 and Tup12, and locally antagonize their repressive functions on Atf1 binding. These results reveal a new mechanism in which upstream noncoding transcription locally magnifies the specific activation of stress-inducible genes via counteraction of corepressors.
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Affiliation(s)
- Naomichi Takemata
- Department of Life Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan
| | - Arisa Oda
- Department of Life Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan
| | - Takatomi Yamada
- Department of Biological Sciences, Chuo University, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Josephine Galipon
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0035, Japan
| | - Tomoichiro Miyoshi
- Department of Life Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan
| | - Yutaka Suzuki
- Department of Medical Genome Sciences, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - Sumio Sugano
- Department of Medical Genome Sciences, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | | | - Kouji Hirota
- Department of Chemistry, Tokyo Metropolitan University, Hachi-Ohji, Tokyo 192-0397, Japan
| | - Kunihiro Ohta
- Department of Life Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan Department of Biological Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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89
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Fujimoto M, Mano Y, Anai M, Yamamoto S, Fukuyo M, Aburatani H, Kaneda A. Epigenetic alteration to activate Bmp2-Smad signaling in Raf-induced senescence. World J Biol Chem 2016; 7:188-205. [PMID: 26981207 PMCID: PMC4768123 DOI: 10.4331/wjbc.v7.i1.188] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 10/30/2015] [Accepted: 12/04/2015] [Indexed: 02/05/2023] Open
Abstract
AIM: To investigate epigenomic and gene expression alterations during cellular senescence induced by oncogenic Raf.
METHODS: Cellular senescence was induced into mouse embryonic fibroblasts (MEFs) by infecting retrovirus to express oncogenic Raf (RafV600E). RNA was collected from RafV600E cells as well as MEFs without infection and MEFs with mock infection, and a genome-wide gene expression analysis was performed using microarray. The epigenomic status for active H3K4me3 and repressive H3K27me3 histone marks was analyzed by chromatin immunoprecipitation-sequencing for RafV600E cells on day 7 and for MEFs without infection. These data for Raf-induced senescence were compared with data for Ras-induced senescence that were obtained in our previous study. Gene knockdown and overexpression were done by retrovirus infection.
RESULTS: Although the expression of some genes including secreted factors was specifically altered in either Ras- or Raf-induced senescence, many genes showed similar alteration pattern in Raf- and Ras-induced senescence. A total of 841 commonly upregulated 841 genes and 573 commonly downregulated genes showed a significant enrichment of genes related to signal and secreted proteins, suggesting the importance of alterations in secreted factors. Bmp2, a secreted protein to activate Bmp2-Smad signaling, was highly upregulated with gain of H3K4me3 and loss of H3K27me3 during Raf-induced senescence, as previously detected in Ras-induced senescence, and the knockdown of Bmp2 by shRNA lead to escape from Raf-induced senescence. Bmp2-Smad inhibitor Smad6 was strongly repressed with H3K4me3 loss in Raf-induced senescence, as detected in Ras-induced senescence, and senescence was also bypassed by Smad6 induction in Raf-activated cells. Different from Ras-induced senescence, however, gain of H3K27me3 did not occur in the Smad6 promoter region during Raf-induced senescence. When comparing genome-wide alteration between Ras- and Raf-induced senescence, genes showing loss of H3K27me3 during senescence significantly overlapped; genes showing H3K4me3 gain, or those showing H3K4me3 loss, also well-overlapped between Ras- and Raf-induced senescence. However, genes with gain of H3K27me3 overlapped significantly rarely, compared with those with H3K27me3 loss, with H3K4me3 gain, or with H3K4me3 loss.
CONCLUSION: Although epigenetic alterations are partly different, Bmp2 upregulation and Smad6 repression occur and contribute to Raf-induced senescence, as detected in Ras-induced senescence.
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Yan K, Arfat Y, Li D, Zhao F, Chen Z, Yin C, Sun Y, Hu L, Yang T, Qian A. Structure Prediction: New Insights into Decrypting Long Noncoding RNAs. Int J Mol Sci 2016; 17:ijms17010132. [PMID: 26805815 PMCID: PMC4730372 DOI: 10.3390/ijms17010132] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 12/18/2015] [Accepted: 01/12/2016] [Indexed: 12/31/2022] Open
Abstract
Long noncoding RNAs (lncRNAs), which form a diverse class of RNAs, remain the least understood type of noncoding RNAs in terms of their nature and identification. Emerging evidence has revealed that a small number of newly discovered lncRNAs perform important and complex biological functions such as dosage compensation, chromatin regulation, genomic imprinting, and nuclear organization. However, understanding the wide range of functions of lncRNAs related to various processes of cellular networks remains a great experimental challenge. Structural versatility is critical for RNAs to perform various functions and provides new insights into probing the functions of lncRNAs. In recent years, the computational method of RNA structure prediction has been developed to analyze the structure of lncRNAs. This novel methodology has provided basic but indispensable information for the rapid, large-scale and in-depth research of lncRNAs. This review focuses on mainstream RNA structure prediction methods at the secondary and tertiary levels to offer an additional approach to investigating the functions of lncRNAs.
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Affiliation(s)
- Kun Yan
- Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Xilu, Xi'an 710072, China.
| | - Yasir Arfat
- Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Xilu, Xi'an 710072, China.
| | - Dijie Li
- Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Xilu, Xi'an 710072, China.
| | - Fan Zhao
- Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Xilu, Xi'an 710072, China.
| | - Zhihao Chen
- Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Xilu, Xi'an 710072, China.
| | - Chong Yin
- Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Xilu, Xi'an 710072, China.
| | - Yulong Sun
- Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Xilu, Xi'an 710072, China.
| | - Lifang Hu
- Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Xilu, Xi'an 710072, China.
| | - Tuanmin Yang
- Department of Bone Disease Oncology, Hong-Hui Hospital, Xi'an Jiaotong University College of Medicine, South Door slightly Friendship Road 555, Xi'an 710054, China.
| | - Airong Qian
- Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi Xilu, Xi'an 710072, China.
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91
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Xu X, Yu T, Chen SJ. Understanding the kinetic mechanism of RNA single base pair formation. Proc Natl Acad Sci U S A 2016; 113:116-21. [PMID: 26699466 PMCID: PMC4711849 DOI: 10.1073/pnas.1517511113] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
RNA functions are intrinsically tied to folding kinetics. The most elementary step in RNA folding is the closing and opening of a base pair. Understanding this elementary rate process is the basis for RNA folding kinetics studies. Previous studies mostly focused on the unfolding of base pairs. Here, based on a hybrid approach, we investigate the folding process at level of single base pairing/stacking. The study, which integrates molecular dynamics simulation, kinetic Monte Carlo simulation, and master equation methods, uncovers two alternative dominant pathways: Starting from the unfolded state, the nucleotide backbone first folds to the native conformation, followed by subsequent adjustment of the base conformation. During the base conformational rearrangement, the backbone either retains the native conformation or switches to nonnative conformations in order to lower the kinetic barrier for base rearrangement. The method enables quantification of kinetic partitioning among the different pathways. Moreover, the simulation reveals several intriguing ion binding/dissociation signatures for the conformational changes. Our approach may be useful for developing a base pair opening/closing rate model.
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Affiliation(s)
- Xiaojun Xu
- Department of Physics, University of Missouri, Columbia, MO 65211; Department of Biochemistry, University of Missouri, Columbia, MO 65211; Informatics Institute, University of Missouri, Columbia, MO 65211
| | - Tao Yu
- Department of Physics, University of Missouri, Columbia, MO 65211; Department of Biochemistry, University of Missouri, Columbia, MO 65211; Informatics Institute, University of Missouri, Columbia, MO 65211; Department of Physics, Jianghan University, Wuhan, Hubei 430056, China
| | - Shi-Jie Chen
- Department of Physics, University of Missouri, Columbia, MO 65211; Department of Biochemistry, University of Missouri, Columbia, MO 65211; Informatics Institute, University of Missouri, Columbia, MO 65211;
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92
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Mellor J, Woloszczuk R, Howe FS. The Interleaved Genome. Trends Genet 2016; 32:57-71. [DOI: 10.1016/j.tig.2015.10.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 09/29/2015] [Accepted: 10/23/2015] [Indexed: 12/25/2022]
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The conservation and signatures of lincRNAs in Marek's disease of chicken. Sci Rep 2015; 5:15184. [PMID: 26471251 PMCID: PMC4608010 DOI: 10.1038/srep15184] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 09/15/2015] [Indexed: 01/10/2023] Open
Abstract
Long intergenic non-coding RNAs (lincRNAs) associated with a number of cancers and other diseases have been identified in mammals, but they are still formidable to be comprehensively identified and characterized. Marek's disease (MD) is a T cell lymphoma of chickens induced by Marek's disease virus (MDV). Here, we used a MD chicken model to develop a precise pipeline for identifying lincRNAs and to determine the roles of lincRNAs in T cell tumorigenesis. More than 1,000 lincRNA loci were identified in chicken bursa. Computational analyses demonstrated that lincRNAs are conserved among different species such as human, mouse and chicken. The putative lincRNAs were found to be associated with a wide range of biological functions including immune responses. Interestingly, we observed distinct lincRNA expression signatures in bursa between MD resistant and susceptible lines of chickens. One of the candidate lincRNAs, termed linc-satb1, was found to play a crucial role in MD immune response by regulating a nearby protein-coding gene SATB1. Thus, our results manifested that lincRNAs may exert considerable influence on MDV-induced T cell tumorigenesis and provide a rich resource for hypothesis-driven functional studies to reveal genetic mechanisms underlying susceptibility to tumorigenesis.
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94
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Sarkar D, Leung EY, Baguley BC, Finlay GJ, Askarian-Amiri ME. Epigenetic regulation in human melanoma: past and future. Epigenetics 2015; 10:103-21. [PMID: 25587943 PMCID: PMC4622872 DOI: 10.1080/15592294.2014.1003746] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The development and progression of melanoma have been attributed to independent or combined genetic and epigenetic events. There has been remarkable progress in understanding melanoma pathogenesis in terms of genetic alterations. However, recent studies have revealed a complex involvement of epigenetic mechanisms in the regulation of gene expression, including methylation, chromatin modification and remodeling, and the diverse activities of non-coding RNAs. The roles of gene methylation and miRNAs have been relatively well studied in melanoma, but other studies have shown that changes in chromatin status and in the differential expression of long non-coding RNAs can lead to altered regulation of key genes. Taken together, they affect the functioning of signaling pathways that influence each other, intersect, and form networks in which local perturbations disturb the activity of the whole system. Here, we focus on how epigenetic events intertwine with these pathways and contribute to the molecular pathogenesis of melanoma.
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Key Words
- 5hmC, 5-hydroxymethylcytosine
- 5mC, 5-methylcytosine
- ACE, angiotensin converting enzyme
- ANCR, anti-differentiation non-coding RNA
- ANRIL, antisense noncoding RNA in INK4 locus
- ASK1, apoptosis signal-regulating kinase 1
- ATRA, all-trans retinoic acid
- BANCR, BRAF-activated non-coding RNA
- BCL-2, B-cell lymphoma 2
- BRAF, B-Raf proto-oncogene, serine/threonine kinase
- BRG1, ATP-dependent helicase SMARCA4
- CAF-1, chromatin assembly factor-1
- CBX7, chromobox homolog 7
- CCND1, cyclin D1
- CD28, cluster of differentiation 28
- CDK, cyclin-dependent kinase
- CDKN2A/B, cyclin-dependent kinase inhibitor 2A/B
- CHD8, chromodomain-helicase DNA-binding protein 8
- CREB, cAMP response element-binding protein
- CUDR, cancer upregulated drug resistant
- Cdc6, cell division cycle 6
- DNA methylation/demethylation
- DNMT, DNA methyltransferase
- EMT, epithelial-mesenchymal transition
- ERK, extracellular signal-regulated kinase
- EZH2, enhancer of zeste homolog 2
- GPCRs, G-protein coupled receptors
- GSK3a, glycogen synthase kinase 3 α
- GWAS, genome-wide association study
- HDAC, histone deacetylase
- HOTAIR, HOX antisense intergenic RNA
- IAP, inhibitor of apoptosis
- IDH2, isocitrate dehydrogenase
- IFN, interferon, interleukin 23
- JNK, Jun N-terminal kinase
- Jak/STAT, Janus kinase/signal transducer and activator of transcription
- MAFG, v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog G
- MALAT1, metastasis-associated lung adenocarcinoma transcript 1
- MAPK, mitogen-activated protein kinase
- MC1R, melanocortin-1 receptor
- MGMT, O6-methylguanine-DNA methyltransferase
- MIF, macrophage migration inhibitory factor
- MITF, microphthalmia-associated transcription factor
- MRE, miRNA recognition element
- MeCP2, methyl CpG binding protein 2
- NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells
- NOD, nucleotide-binding and oligomerization domain
- PBX, pre-B-cell leukemia homeobox
- PEDF, pigment epithelium derived factor
- PI3K, phosphatidylinositol-4, 5-bisphosphate 3-kinase
- PIB5PA, phosphatidylinositol-4, 5-biphosphate 5-phosphatase A
- PKA, protein kinase A
- PRC, polycomb repressor complex
- PSF, PTB associated splicing factor
- PTB, polypyrimidine tract-binding
- PTEN, phosphatase and tensin homolog
- RARB, retinoic acid receptor-β2
- RASSF1A, Ras association domain family 1A
- SETDB1, SET Domain, bifurcated 1
- SPRY4, Sprouty 4
- STAU1, Staufen1
- SWI/SNF, SWItch/Sucrose Non-Fermentable
- TCR, T-cell receptor
- TET, ten eleven translocase
- TGF β, transforming growth factor β
- TINCR, tissue differentiation-inducing non-protein coding RNA
- TOR, target of rapamycin
- TP53, tumor protein 53
- TRAF6, TNF receptor-associated factor 6
- UCA1, urothelial carcinoma-associated 1
- ceRNA, competitive endogenous RNAs
- chromatin modification
- chromatin remodeling
- epigenetics
- gene regulation
- lncRNA, long ncRNA
- melanoma
- miRNA, micro RNA
- ncRNA, non-coding RNA
- ncRNAs
- p14ARF, p14 alternative reading frame
- p16INK4a, p16 inhibitor of CDK4
- pRB, retinoblastoma protein
- snoRNA, small nucleolar RNA
- α-MSHm, α-melanocyte stimulating hormone
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Affiliation(s)
- Debina Sarkar
- a Auckland Cancer Society Research Center ; University of Auckland ; Auckland , New Zealand
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95
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Hoffman CS, Wood V, Fantes PA. An Ancient Yeast for Young Geneticists: A Primer on the Schizosaccharomyces pombe Model System. Genetics 2015; 201:403-23. [PMID: 26447128 PMCID: PMC4596657 DOI: 10.1534/genetics.115.181503] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The fission yeast Schizosaccharomyces pombe is an important model organism for the study of eukaryotic molecular and cellular biology. Studies of S. pombe, together with studies of its distant cousin, Saccharomyces cerevisiae, have led to the discovery of genes involved in fundamental mechanisms of transcription, translation, DNA replication, cell cycle control, and signal transduction, to name but a few processes. However, since the divergence of the two species approximately 350 million years ago, S. pombe appears to have evolved less rapidly than S. cerevisiae so that it retains more characteristics of the common ancient yeast ancestor, causing it to share more features with metazoan cells. This Primer introduces S. pombe by describing the yeast itself, providing a brief description of the origins of fission yeast research, and illustrating some genetic and bioinformatics tools used to study protein function in fission yeast. In addition, a section on some key differences between S. pombe and S. cerevisiae is included for readers with some familiarity with budding yeast research but who may have an interest in developing research projects using S. pombe.
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Affiliation(s)
- Charles S Hoffman
- Biology Department, Boston College, Chestnut Hill, Massachusetts 02467
| | - Valerie Wood
- Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, CB2 1GA Cambridge, United Kingdom
| | - Peter A Fantes
- School of Biological Sciences, College of Science and Engineering, University of Edinburgh EH9 3JR Edinburgh, United Kingdom
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96
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Protein synthesis as an integral quality control mechanism during ageing. Ageing Res Rev 2015; 23:75-89. [PMID: 25555680 DOI: 10.1016/j.arr.2014.12.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/18/2014] [Accepted: 12/22/2014] [Indexed: 01/17/2023]
Abstract
Ageing is manifested as functional and structural deterioration that affects cell and tissue physiology. mRNA translation is a central cellular process, supplying cells with newly synthesized proteins. Accumulating evidence suggests that alterations in protein synthesis are not merely a corollary but rather a critical factor for the progression of ageing. Here, we survey protein synthesis regulatory mechanisms and focus on the pre-translational regulation of the process exerted by non-coding RNA species, RNA binding proteins and alterations of intrinsic RNA properties. In addition, we discuss the tight relationship between mRNA translation and two central pathways that modulate ageing, namely the insulin/IGF-1 and TOR signalling cascades. A thorough understanding of the complex interplay between protein synthesis regulation and ageing will provide critical insights into the pathogenesis of age-related disorders, associated with impaired proteostasis and protein quality control.
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97
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Yamashita A, Shichino Y, Yamamoto M. The long non-coding RNA world in yeasts. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1859:147-54. [PMID: 26265144 DOI: 10.1016/j.bbagrm.2015.08.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/29/2015] [Accepted: 08/06/2015] [Indexed: 12/26/2022]
Abstract
In recent years, it has become evident that eukaryotic genomes are pervasively transcribed and produce numerous non-coding transcripts, including long non-coding RNAs (lncRNAs). Although research of such genomic enigmas is in the early stages, a growing number of lncRNAs have been characterized and found to be principal actors in a variety of biological processes rather than merely representing transcriptional noise. Here, we review recent findings on lncRNAs in yeast systems. We especially focus on lncRNA-mediated cellular regulations to respond to environmental changes in the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe. This article is part of a Special Issue entitled: Clues to long noncoding RNA taxonomy1, edited by Dr. Tetsuro Hirose and Dr. Shinichi Nakagawa.
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Affiliation(s)
- Akira Yamashita
- Laboratory of Cell Responses, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan; Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan.
| | - Yuichi Shichino
- Laboratory of Cell Responses, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Masayuki Yamamoto
- Laboratory of Cell Responses, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan; Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan
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98
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Materne P, Anandhakumar J, Migeot V, Soriano I, Yague-Sanz C, Hidalgo E, Mignion C, Quintales L, Antequera F, Hermand D. Promoter nucleosome dynamics regulated by signalling through the CTD code. eLife 2015; 4:e09008. [PMID: 26098123 PMCID: PMC4502402 DOI: 10.7554/elife.09008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 06/19/2015] [Indexed: 12/26/2022] Open
Abstract
The phosphorylation of the RNA polymerase II C-terminal domain (CTD) plays a key role in delineating transcribed regions within chromatin by recruiting histone methylases and deacetylases. Using genome-wide nucleosome mapping, we show that CTD S2 phosphorylation controls nucleosome dynamics in the promoter of a subset of 324 genes, including the regulators of cell differentiation ste11 and metabolic adaptation inv1. Mechanistic studies on these genes indicate that during gene activation a local increase of phospho-S2 CTD nearby the promoter impairs the phospho-S5 CTD-dependent recruitment of Set1 and the subsequent recruitment of specific HDACs, which leads to nucleosome depletion and efficient transcription. The early increase of phospho-S2 results from the phosphorylation of the CTD S2 kinase Lsk1 by MAP kinase in response to cellular signalling. The artificial tethering of the Lsk1 kinase at the ste11 promoter is sufficient to activate transcription. Therefore, signalling through the CTD code regulates promoter nucleosomes dynamics. DOI:http://dx.doi.org/10.7554/eLife.09008.001 The process of activating genes—known as gene expression—involves a number of steps. During the first step, the gene's DNA is copied or ‘transcribed’ to produce a molecule of messenger RNA. However, most of the DNA in a cell is wrapped around proteins called histones to make structures known as nucleosomes, and the DNA has to be unpacked to allow the enzymes that make messenger RNA to access it. Cells regulate how the DNA is packed by attaching chemical groups to the histone proteins. Adding acetyl groups to histones usually causes the nucleosomes to unwrap and creates loosely packed DNA that helps with gene expression. On the other hand, the addition of methyl groups has the opposite effect. RNA polymerase II is the enzyme that carries out transcription of messenger RNAs in all eukaryotic cells—that is, the cells of organisms like plants, animals, and fungi. Like all enzymes, RNA polymerase II is made of smaller building blocks called amino acids. One end of the RNA polymerase II enzyme, called the C-terminal domain (or CTD), contains a unique sequence of amino acids that serves as a scaffold to recruit other proteins involved in transcription and histone modifications. Different amino acids in this region of RNA polymerase II can be modified by the addition of phosphate groups. The pattern of these modifications is often thought of as a code and can influence which other proteins get recruited. It remains poorly understood how RNA polymerase II regulates nucleosomes to allow transcription to occur. Materne, Anandhakumar et al. have now addressed this issue by engineering mutant yeast cells in which phosphate groups cannot be added to specific amino acids in the RNA polymerase II enzyme. Most genes were expressed as normal in these yeast cells, but a few hundred genes were not expressed. Materne, Anandhakumar et al. then used a technique called MNase-Seq to map the position of nucleosomes across the genome and found that there were more nucleosomes near to start of these down-regulated genes. Further experiments showed that the addition of phosphate groups onto the RNA polymerase II is required to deplete the nucleosomes at the start of a gene called ste11, which allows transcription to occur. Materne, Anandhakumar et al. also found that artificially tethering the enzyme that adds phosphate groups to the C-terminal domain to the start of the ste11 gene was sufficient to oust nucleosomes and activate transcription by RNA polymerase II. Future work will address if this newly discovered mechanism is implicated in the activation of specific patterns of gene expression during the development of more complex organisms. DOI:http://dx.doi.org/10.7554/eLife.09008.002
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Affiliation(s)
- Philippe Materne
- URPHYM-GEMO, Namur Research College, University of Namur, Namur, Belgium
| | | | - Valerie Migeot
- URPHYM-GEMO, Namur Research College, University of Namur, Namur, Belgium
| | - Ignacio Soriano
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Carlo Yague-Sanz
- URPHYM-GEMO, Namur Research College, University of Namur, Namur, Belgium
| | - Elena Hidalgo
- Departament de Ciencies Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Carole Mignion
- URPHYM-GEMO, Namur Research College, University of Namur, Namur, Belgium
| | - Luis Quintales
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Francisco Antequera
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Damien Hermand
- URPHYM-GEMO, Namur Research College, University of Namur, Namur, Belgium
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Kannan S, Chernikova D, Rogozin IB, Poliakov E, Managadze D, Koonin EV, Milanesi L. Transposable Element Insertions in Long Intergenic Non-Coding RNA Genes. Front Bioeng Biotechnol 2015; 3:71. [PMID: 26106594 PMCID: PMC4460805 DOI: 10.3389/fbioe.2015.00071] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 05/06/2015] [Indexed: 11/13/2022] Open
Abstract
Transposable elements (TEs) are abundant in mammalian genomes and appear to have contributed to the evolution of their hosts by providing novel regulatory or coding sequences. We analyzed different regions of long intergenic non-coding RNA (lincRNA) genes in human and mouse genomes to systematically assess the potential contribution of TEs to the evolution of the structure and regulation of expression of lincRNA genes. Introns of lincRNA genes contain the highest percentage of TE-derived sequences (TES), followed by exons and then promoter regions although the density of TEs is not significantly different between exons and promoters. Higher frequencies of ancient TEs in promoters and exons compared to introns implies that many lincRNA genes emerged before the split of primates and rodents. The content of TES in lincRNA genes is substantially higher than that in protein-coding genes, especially in exons and promoter regions. A significant positive correlation was detected between the content of TEs and evolutionary rate of lincRNAs indicating that inserted TEs are preferentially fixed in fast-evolving lincRNA genes. These results are consistent with the repeat insertion domains of LncRNAs hypothesis under which TEs have substantially contributed to the origin, evolution, and, in particular, fast functional diversification, of lincRNA genes.
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Affiliation(s)
- Sivakumar Kannan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health , Bethesda, MD , USA
| | - Diana Chernikova
- Department of Genetics, Institute for Quantitative Biomedical Sciences, Geisel School of Medicine, Dartmouth College , Hanover, NH , USA
| | - Igor B Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health , Bethesda, MD , USA
| | - Eugenia Poliakov
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health , Bethesda, MD , USA
| | - David Managadze
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health , Bethesda, MD , USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health , Bethesda, MD , USA
| | - Luciano Milanesi
- Institute for Biomedical Technologies, National Research Council , Segrate , Italy
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100
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Halder A, Halder S, Bhattacharyya D, Mitra A. Feasibility of occurrence of different types of protonated base pairs in RNA: a quantum chemical study. Phys Chem Chem Phys 2015; 16:18383-96. [PMID: 25070186 DOI: 10.1039/c4cp02541e] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Protonated nucleobases have significant roles in facilitating catalytic functions of RNA, and in stabilizing different structural motifs. Reported pKa values of nucleobase protonation suggest that the population of neutral nucleobases is 10(3)-10(4) times higher than that of protonated nucleobases under physiological conditions (pH ∼ 7.4). Therefore, a molecular level understanding of various putative roles of protonated nucleobases cannot be achieved without addressing the question of how their occurrence propensities and stabilities are related to the free energy costs associated with the process of protonation under physiological conditions. With water as the proton donor, we use advanced QM methods to evaluate the site specific protonation propensities of nucleobases in terms of their associated free energy changes (ΔGprot). Quantitative follow up on the energetics of base pair formation and database search for evaluating their occurrence frequencies, reveal a lack of correlation between base pair stability and occurrence propensities on the one hand, and ease of protonation on the other. For example, although N7 protonated adenine (ΔGprot = 40.0 kcal mol(-1)) is found to participate in stable base pairing, base pairs involving N7 protonated guanine (ΔGprot = 36.8 kcal mol(-1)), on geometry optimization, converge to a minima where guanine transfers its extra proton to its partner base. Such observations, along with examples of weak base pairs involving N3 protonation of cytosine (ΔGprot = 37.0 kcal mol(-1)) are rationalized by analysing the protonation induced charge redistributions which are found to significantly influence, both positively and negatively, the hydrogen bonding potentials of different functional sites of individual nucleobases. Protonation induced charge redistribution is also found to strongly influence (i) the aromatic character of the rings of the participating bases and (ii) hydrogen bonding potential of the free edges of the protonated base pair. Comprehensive analysis of a non-redundant RNA crystal structure dataset further reveals that, while availability of stabilization possibilities determine the feasibility of occurrence of protonated bases, their occurrence context and specific functional roles are important factors determining their occurrence propensities.
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Affiliation(s)
- Antarip Halder
- Center for Computational Natural Sciences and Bioinformatics (CCNSB), International Institute of Information Technology (IIIT-H), Gachibowli, Hyderabad 500032, India.
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