1
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Bray SM, Hämälä T, Zhou M, Busoms S, Fischer S, Desjardins SD, Mandáková T, Moore C, Mathers TC, Cowan L, Monnahan P, Koch J, Wolf EM, Lysak MA, Kolar F, Higgins JD, Koch MA, Yant L. Kinetochore and ionomic adaptation to whole-genome duplication in Cochlearia shows evolutionary convergence in three autopolyploids. Cell Rep 2024; 43:114576. [PMID: 39116207 DOI: 10.1016/j.celrep.2024.114576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 05/17/2024] [Accepted: 07/18/2024] [Indexed: 08/10/2024] Open
Abstract
Whole-genome duplication (WGD) occurs in all kingdoms and impacts speciation, domestication, and cancer outcome. However, doubled DNA management can be challenging for nascent polyploids. The study of within-species polyploidy (autopolyploidy) permits focus on this DNA management aspect, decoupling it from the confounding effects of hybridization (in allopolyploid hybrids). How is autopolyploidy tolerated, and how do young polyploids stabilize? Here, we introduce a powerful model to address this: the genus Cochlearia, which has experienced many polyploidization events. We assess meiosis and other polyploid-relevant phenotypes, generate a chromosome-scale genome, and sequence 113 individuals from 33 ploidy-contrasting populations. We detect an obvious autopolyploidy-associated selection signal at kinetochore components and ion transporters. Modeling the selected alleles, we detail evidence of the kinetochore complex mediating adaptation to polyploidy. We compare candidates in independent autopolyploids across three genera separated by 40 million years, highlighting a common function at the process and gene levels, indicating evolutionary flexibility in response to polyploidy.
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Affiliation(s)
- Sian M Bray
- The University of Nottingham, Nottingham NG7 2RD, UK; The John Innes Centre, Norwich NR4 7UH, UK
| | - Tuomas Hämälä
- The University of Nottingham, Nottingham NG7 2RD, UK
| | - Min Zhou
- The University of Nottingham, Nottingham NG7 2RD, UK
| | - Silvia Busoms
- The John Innes Centre, Norwich NR4 7UH, UK; Department of Plant Physiology, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
| | - Sina Fischer
- The University of Nottingham, Nottingham NG7 2RD, UK
| | - Stuart D Desjardins
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Terezie Mandáková
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Chris Moore
- The University of Nottingham, Nottingham NG7 2RD, UK
| | - Thomas C Mathers
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Laura Cowan
- The University of Nottingham, Nottingham NG7 2RD, UK
| | | | | | - Eva M Wolf
- Centre for Organismal Studies (COS), Heidelberg University, 69120 Heidelberg, Germany
| | - Martin A Lysak
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Filip Kolar
- Department of Botany, Charles University, Benátská 2, 12801 Prague, Czech Republic; The Czech Academy of Sciences, Zámek 1, 252 43 Průhonice, Czech Republic
| | - James D Higgins
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Marcus A Koch
- Centre for Organismal Studies (COS), Heidelberg University, 69120 Heidelberg, Germany
| | - Levi Yant
- The University of Nottingham, Nottingham NG7 2RD, UK; Department of Botany, Charles University, Benátská 2, 12801 Prague, Czech Republic.
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2
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Dard A, Van Breusegem F, Mhamdi A. Redox regulation of gene expression: proteomics reveals multiple previously undescribed redox-sensitive cysteines in transcription complexes and chromatin modifiers. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4476-4493. [PMID: 38642390 DOI: 10.1093/jxb/erae177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 04/17/2024] [Indexed: 04/22/2024]
Abstract
Redox signalling is crucial for regulating plant development and adaptation to environmental changes. Proteins with redox-sensitive cysteines can sense oxidative stress and modulate their functions. Recent proteomics efforts have comprehensively mapped the proteins targeted by oxidative modifications. The nucleus, the epicentre of transcriptional reprogramming, contains a large number of proteins that control gene expression. Specific redox-sensitive transcription factors have long been recognized as key players in decoding redox signals in the nucleus and thus in regulating transcriptional responses. Consequently, the redox regulation of the nuclear transcription machinery and its cofactors has received less attention. In this review, we screened proteomic datasets for redox-sensitive cysteines on proteins of the core transcription complexes and chromatin modifiers in Arabidopsis thaliana. Our analysis indicates that redox regulation affects every step of gene transcription, from initiation to elongation and termination. We report previously undescribed redox-sensitive subunits in transcription complexes and discuss the emerging challenges in unravelling the landscape of redox-regulated processes involved in nuclear gene transcription.
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Affiliation(s)
- Avilien Dard
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
| | - Frank Van Breusegem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
| | - Amna Mhamdi
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Gent, Belgium
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3
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Corrêa RL, Kutnjak D, Ambrós S, Bustos M, Elena SF. Identification of epigenetically regulated genes involved in plant-virus interaction and their role in virus-triggered induced resistance. BMC PLANT BIOLOGY 2024; 24:172. [PMID: 38443837 PMCID: PMC10913459 DOI: 10.1186/s12870-024-04866-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 02/26/2024] [Indexed: 03/07/2024]
Abstract
BACKGROUND Plant responses to a wide range of stresses are known to be regulated by epigenetic mechanisms. Pathogen-related investigations, particularly against RNA viruses, are however scarce. It has been demonstrated that Arabidopsis thaliana plants defective in some members of the RNA-directed DNA methylation (RdDM) or histone modification pathways presented differential susceptibility to the turnip mosaic virus. In order to identify genes directly targeted by the RdDM-related RNA Polymerase V (POLV) complex and the histone demethylase protein JUMONJI14 (JMJ14) during infection, the transcriptomes of infected mutant and control plants were obtained and integrated with available chromatin occupancy data for various epigenetic proteins and marks. RESULTS A comprehensive list of virus-responsive gene candidates to be regulated by the two proteins was obtained. Twelve genes were selected for further characterization, confirming their dynamic regulation during the course of infection. Several epigenetic marks on their promoter sequences were found using in silico data, raising confidence that the identified genes are actually regulated by epigenetic mechanisms. The altered expression of six of these genes in mutants of the methyltransferase gene CURLY LEAF and the histone deacetylase gene HISTONE DEACETYLASE 19 suggests that some virus-responsive genes may be regulated by multiple coordinated epigenetic complexes. A temporally separated multiple plant virus infection experiment in which plants were transiently infected with one virus and then infected by a second one was designed to investigate the possible roles of the identified POLV- and JMJ14-regulated genes in wild-type (WT) plants. Plants that had previously been stimulated with viruses were found to be more resistant to subsequent virus challenge than control plants. Several POLV- and JMJ14-regulated genes were found to be regulated in virus induced resistance in WT plants, with some of them poisoned to be expressed in early infection stages. CONCLUSIONS A set of confident candidate genes directly regulated by the POLV and JMJ14 proteins during virus infection was identified, with indications that some of them may be regulated by multiple epigenetic modules. A subset of these genes may also play a role in the tolerance of WT plants to repeated, intermittent virus infections.
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Affiliation(s)
- Régis L Corrêa
- Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Cientificas (CSIC) - Universitat de València (UV), Paterna, Valencia, 46980, Spain.
- Department of Genetics, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, 21941-590, Brazil.
| | - Denis Kutnjak
- Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Cientificas (CSIC) - Universitat de València (UV), Paterna, Valencia, 46980, Spain
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, 1000, Slovenia
| | - Silvia Ambrós
- Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Cientificas (CSIC) - Universitat de València (UV), Paterna, Valencia, 46980, Spain
| | - Mónica Bustos
- Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Cientificas (CSIC) - Universitat de València (UV), Paterna, Valencia, 46980, Spain
| | - Santiago F Elena
- Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Cientificas (CSIC) - Universitat de València (UV), Paterna, Valencia, 46980, Spain
- The Santa Fe Institute, Santa Fe, NM, 87501, USA
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4
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Serrano A, Moret M, Fernández-Parras I, Bombarely A, Luque F, Navarro F. RNA Polymerases IV and V Are Involved in Olive Fruit Development. Genes (Basel) 2023; 15:1. [PMID: 38275583 PMCID: PMC10815247 DOI: 10.3390/genes15010001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/11/2023] [Accepted: 12/15/2023] [Indexed: 01/27/2024] Open
Abstract
Transcription is carried out in most eukaryotes by three multimeric complexes (RNA polymerases I, II and III). However, plants contain two additional RNA polymerases (IV and V), which have evolved from RNA polymerase II. RNA polymerases II, IV and V contain both common and specific subunits that may specialise some of their functions. In this study, we conducted a search for the genes that putatively code for the specific subunits of RNA polymerases IV and V, as well as those corresponding to RNA polymerase II in olive trees. Based on the homology with the genes of Arabidopsis thaliana, we identified 13 genes that putatively code for the specific subunits of polymerases IV and V, and 16 genes that code for the corresponding specific subunits of polymerase II in olives. The transcriptomic analysis by RNA-Seq revealed that the expression of the RNA polymerases IV and V genes was induced during the initial stages of fruit development. Given that RNA polymerases IV and V are involved in the transcription of long non-coding RNAs, we investigated their expression and observed relevant changes in the expression of this type of RNAs. Particularly, the expression of the intergenic and intronic long non-coding RNAs tended to increase in the early steps of fruit development, suggesting their potential role in this process. The positive correlation between the expression of RNA polymerases IV and V subunits and the expression of non-coding RNAs supports the hypothesis that RNA polymerases IV and V may play a role in fruit development through the synthesis of this type of RNAs.
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Affiliation(s)
- Alicia Serrano
- Instituto Universitario de Investigación en Olivar y Aceites de Oliva, Universidad de Jaén, 23071 Jaén, Spain; (A.S.); (M.M.); (I.F.-P.)
| | - Martín Moret
- Instituto Universitario de Investigación en Olivar y Aceites de Oliva, Universidad de Jaén, 23071 Jaén, Spain; (A.S.); (M.M.); (I.F.-P.)
| | - Isabel Fernández-Parras
- Instituto Universitario de Investigación en Olivar y Aceites de Oliva, Universidad de Jaén, 23071 Jaén, Spain; (A.S.); (M.M.); (I.F.-P.)
| | - Aureliano Bombarely
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC and Universitat Politécnica de Valencia, 46011 Valencia, Spain;
| | - Francisco Luque
- Instituto Universitario de Investigación en Olivar y Aceites de Oliva, Universidad de Jaén, 23071 Jaén, Spain; (A.S.); (M.M.); (I.F.-P.)
| | - Francisco Navarro
- Departamento de Biología Experimental, Universidad de Jaén, 23071 Jaén, Spain
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5
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Yang DL, Huang K, Deng D, Zeng Y, Wang Z, Zhang Y. DNA-dependent RNA polymerases in plants. THE PLANT CELL 2023; 35:3641-3661. [PMID: 37453082 PMCID: PMC10533338 DOI: 10.1093/plcell/koad195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 06/09/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
DNA-dependent RNA polymerases (Pols) transfer the genetic information stored in genomic DNA to RNA in all organisms. In eukaryotes, the typical products of nuclear Pol I, Pol II, and Pol III are ribosomal RNAs, mRNAs, and transfer RNAs, respectively. Intriguingly, plants possess two additional Pols, Pol IV and Pol V, which produce small RNAs and long noncoding RNAs, respectively, mainly for silencing transposable elements. The five plant Pols share some subunits, but their distinct functions stem from unique subunits that interact with specific regulatory factors in their transcription cycles. Here, we summarize recent advances in our understanding of plant nucleus-localized Pols, including their evolution, function, structures, and transcription cycles.
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Affiliation(s)
- Dong-Lei Yang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Kun Huang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Deyin Deng
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Lin’an, Hangzhou 311300, China
| | - Yuan Zeng
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhenxing Wang
- College of Horticulture, National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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6
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Zhang S, Wu XQ, Xie HT, Zhao SS, Wu JG. Multifaceted roles of RNA polymerase IV in plant growth and development. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5725-5732. [PMID: 32969476 PMCID: PMC7541909 DOI: 10.1093/jxb/eraa346] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We discuss the latest findings on RNA polymerase IV (Pol IV) in plant growth and development, providing new insights and expanding on new ideas for further, more in-depth research on Pol IV.
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Affiliation(s)
- Shuai Zhang
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Province Key Laboratory of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiao-Qing Wu
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Province Key Laboratory of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Hui-Ting Xie
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Province Key Laboratory of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Shan-Shan Zhao
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Province Key Laboratory of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jian-Guo Wu
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Province Key Laboratory of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
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7
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Characterization of Local and Systemic Impact of Whitefly ( Bemisia tabaci) Feeding and Whitefly-Transmitted Tomato Mottle Virus Infection on Tomato Leaves by Comprehensive Proteomics. Int J Mol Sci 2020; 21:ijms21197241. [PMID: 33008056 PMCID: PMC7583044 DOI: 10.3390/ijms21197241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/21/2020] [Accepted: 09/26/2020] [Indexed: 11/23/2022] Open
Abstract
Tomato mottle virus (ToMoV) is a single-stranded DNA (ssDNA) begomovirus transmitted to solanaceous crops by the whitefly species complex (Bemisia tabaci), causing stunted growth, leaf mottling, and reduced yield. Using a genetic repertoire of seven genes, ToMoV pathogenesis includes the manipulation of multiple plant biological processes to circumvent antiviral defenses. To further understand the effects of whitefly feeding and whitefly-transmitted ToMoV infection on tomato plants (Solanum lycopersicum ‘Florida Lanai’), we generated comprehensive protein profiles of leaves subjected to feeding by either viruliferous whiteflies harboring ToMoV, or non-viruliferous whiteflies, or a no-feeding control. The effects of whitefly feeding and ToMoV infection were measured both locally and systemically by sampling either a mature leaf directly from the site of clip-cage confined whitefly feeding, or from a newly formed leaf 10 days post feeding (dpf). At 3 dpf, tomato’s response to ToMoV included proteins associated with translation initiation and elongation as well as plasmodesmata dynamics. In contrast, systemic impacts of ToMoV on younger leaves 10 dpf were more pronounced and included a virus-specific change in plant proteins associated with mRNA maturation and export, RNA-dependent DNA methylation, and other antiviral plant processes. Our analysis supports previous findings and provides novel insight into tomato’s local and systemic response to whitefly feeding and ToMoV infection.
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8
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Xiong F, Liu HH, Duan CY, Zhang BK, Wei G, Zhang Y, Li S. Arabidopsis JANUS Regulates Embryonic Pattern Formation through Pol II-Mediated Transcription of WOX2 and PIN7. iScience 2019; 19:1179-1188. [PMID: 31542701 PMCID: PMC6831869 DOI: 10.1016/j.isci.2019.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 04/07/2019] [Accepted: 09/04/2019] [Indexed: 02/06/2023] Open
Abstract
Embryonic pattern formation relies on positional coordination of cell division and specification. Early axis formation during Arabidopsis embryogenesis requires WUSCHEL RELATED HOMEOBOX (WOX)-mediated transcription activation and PIN-FORMED7 (PIN7)-mediated auxin asymmetry. How these events are regulated is obscure. We report that Arabidopsis JANUS, a putative subunit of spliceosome, is essential for embryonic pattern formation. Significantly reduced transcription but not mRNA processing of WOX2 and PIN7 in janus suggested its role in transcriptional regulation. JANUS interacts with RNA polymerase II (Pol II) through a region outside of its spliceosome-association domain. We further show that Pol II mediates the transcription of WOX2 and PIN7 in a JANUS-dependent way and is essential for embryonic pattern formation. These findings reveal that JANUS recruits Pol II for the activation of two parallel pathways to ensure proper pattern formation during embryogenesis. Arabidopsis JANUS, a putative spliceosome subunit, is essential for embryogenesis JANUS mediates the transcription but not RNA processing of WOX2 and PIN7 JANUS interacts with RNA polymerase II whose mutations caused embryo lethality Pol II mediates the transcription of WOX2 and PIN7 in a JANUS-dependent manner
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Affiliation(s)
- Feng Xiong
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Hai-Hong Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Cun-Ying Duan
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Bi-Ke Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Guo Wei
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Yan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Sha Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China; Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China.
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9
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Blevins T, Podicheti R, Mishra V, Marasco M, Wang J, Rusch D, Tang H, Pikaard CS. Identification of Pol IV and RDR2-dependent precursors of 24 nt siRNAs guiding de novo DNA methylation in Arabidopsis. eLife 2015; 4:e09591. [PMID: 26430765 PMCID: PMC4716838 DOI: 10.7554/elife.09591] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 10/01/2015] [Indexed: 12/21/2022] Open
Abstract
In Arabidopsis thaliana, abundant 24 nucleotide small interfering RNAs (24 nt siRNA) guide the cytosine methylation and silencing of transposons and a subset of genes. 24 nt siRNA biogenesis requires nuclear RNA polymerase IV (Pol IV), RNA-dependent RNA polymerase 2 (RDR2) and DICER-like 3 (DCL3). However, siRNA precursors are mostly undefined. We identified Pol IV and RDR2-dependent RNAs (P4R2 RNAs) that accumulate in dcl3 mutants and are diced into 24 nt RNAs by DCL3 in vitro. P4R2 RNAs are mostly 26-45 nt and initiate with a purine adjacent to a pyrimidine, characteristics shared by Pol IV transcripts generated in vitro. RDR2 terminal transferase activity, also demonstrated in vitro, may account for occasional non-templated nucleotides at P4R2 RNA 3' termini. The 24 nt siRNAs primarily correspond to the 5' or 3' ends of P4R2 RNAs, suggesting a model whereby siRNAs are generated from either end of P4R2 duplexes by single dicing events.
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Affiliation(s)
- Todd Blevins
- Howard Hughes Medical Institute, Indiana University, Bloomington, United States
- Department of Biology, Indiana University, Bloomington, United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
| | - Ram Podicheti
- Center for Genomics and Bioinformatics, Indiana University, Bloomington, United States
- School of Informatics and Computing, Indiana University, Bloomington, United States
| | - Vibhor Mishra
- Department of Biology, Indiana University, Bloomington, United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
| | - Michelle Marasco
- Department of Biology, Indiana University, Bloomington, United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
| | - Jing Wang
- Department of Biology, Indiana University, Bloomington, United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
| | - Doug Rusch
- Center for Genomics and Bioinformatics, Indiana University, Bloomington, United States
| | - Haixu Tang
- School of Informatics and Computing, Indiana University, Bloomington, United States
| | - Craig S Pikaard
- Howard Hughes Medical Institute, Indiana University, Bloomington, United States
- Department of Biology, Indiana University, Bloomington, United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
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10
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Zhou M, Law JA. RNA Pol IV and V in gene silencing: Rebel polymerases evolving away from Pol II's rules. CURRENT OPINION IN PLANT BIOLOGY 2015; 27:154-64. [PMID: 26344361 PMCID: PMC4618083 DOI: 10.1016/j.pbi.2015.07.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 07/15/2015] [Accepted: 07/19/2015] [Indexed: 05/19/2023]
Abstract
Noncoding RNAs regulate gene expression at both the transcriptional and post-transcriptional levels, and play critical roles in development, imprinting and the maintenance of genome integrity in eukaryotic organisms [1,2,3]. Therefore, it is important to understand how the production of such RNAs are controlled. In addition to the three canonical DNA dependent RNA polymerases (Pol) Pol I, II and III, two non-redundant plant-specific RNA polymerases, Pol IV and Pol V, have been identified and shown to generate noncoding RNAs that are required for transcriptional gene silencing via the RNA-directed DNA methylation (RdDM) pathway. Thus, somewhat paradoxically, transcription is required for gene silencing. This paradox extends beyond plants, as silencing pathways in yeast, fungi, flies, worms, and mammals also require transcriptional machinery [4,5]. As plants have evolved specialized RNA polymerases to carry out gene silencing in a manner that is separate from the essential roles of Pol II, their characterization offers unique insights into how RNA polymerases facilitate gene silencing. In this review, we focus on the mechanisms of Pol IV and Pol V function, including their compositions, their transcripts, and their modes of recruitment to chromatin.
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Affiliation(s)
- Ming Zhou
- Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Julie A Law
- Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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11
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Wang Y, Ma H. Step-wise and lineage-specific diversification of plant RNA polymerase genes and origin of the largest plant-specific subunits. THE NEW PHYTOLOGIST 2015; 207:1198-212. [PMID: 25921392 DOI: 10.1111/nph.13432] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 03/24/2015] [Indexed: 05/25/2023]
Abstract
Proteins often function as complexes, yet little is known about the evolution of dissimilar subunits of complexes. DNA-directed RNA polymerases (RNAPs) are multisubunit complexes, with distinct eukaryotic types for different classes of transcripts. In addition to Pol I-III, common in eukaryotes, plants have Pol IV and V for epigenetic regulation. Some RNAP subunits are specific to one type, whereas other subunits are shared by multiple types. We have conducted extensive phylogenetic and sequence analyses, and have placed RNAP gene duplication events in land plant history, thereby reconstructing the subunit compositions of the novel RNAPs during land plant evolution. We found that Pol IV/V have experienced step-wise duplication and diversification of various subunits, with increasingly distinctive subunit compositions. Also, lineage-specific duplications have further increased RNAP complexity with distinct copies in different plant families and varying divergence for subunits of different RNAPs. Further, the largest subunits of Pol IV/V probably originated from a gene fusion in the ancestral land plants. We propose a framework of plant RNAP evolution, providing an excellent model for protein complex evolution.
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Affiliation(s)
- Yaqiong Wang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, Institute of Plant Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China
- Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering and Institute of Biodiversity Sciences, Fudan University, Shanghai, 200433, China
| | - Hong Ma
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, Institute of Plant Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, China
- Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering and Institute of Biodiversity Sciences, Fudan University, Shanghai, 200433, China
- Institutes of Biomedical Sciences, Fudan University, 138 Yixueyuan Road, Shanghai, 200032, China
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12
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Ream TS, Haag JR, Pontvianne F, Nicora CD, Norbeck AD, Paša-Tolić L, Pikaard CS. Subunit compositions of Arabidopsis RNA polymerases I and III reveal Pol I- and Pol III-specific forms of the AC40 subunit and alternative forms of the C53 subunit. Nucleic Acids Res 2015; 43:4163-78. [PMID: 25813043 PMCID: PMC4417161 DOI: 10.1093/nar/gkv247] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 03/10/2015] [Indexed: 12/17/2022] Open
Abstract
Using affinity purification and mass spectrometry, we identified the subunits of Arabidopsis thaliana multisubunit RNA polymerases I and III (abbreviated as Pol I and Pol III), the first analysis of their physical compositions in plants. In all eukaryotes examined to date, AC40 and AC19 subunits are common to Pol I (a.k.a. Pol A) and Pol III (a.k.a. Pol C) and are encoded by single genes. Surprisingly, A. thaliana and related species express two distinct AC40 paralogs, one of which assembles into Pol I and the other of which assembles into Pol III. Changes at eight amino acid positions correlate with the functional divergence of Pol I- and Pol III-specific AC40 paralogs. Two genes encode homologs of the yeast C53 subunit and either protein can assemble into Pol III. By contrast, only one of two potential C17 variants, and one of two potential C31 variants were detected in Pol III. We introduce a new nomenclature system for plant Pol I and Pol III subunits in which the 12 subunits that are structurally and functionally homologous among Pols I through V are assigned equivalent numbers.
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Affiliation(s)
- Thomas S Ream
- Division of Biology and Biomedical Sciences, Washington University, St. Louis, MO 63130, USA
| | - Jeremy R Haag
- Division of Biology and Biomedical Sciences, Washington University, St. Louis, MO 63130, USA Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Frederic Pontvianne
- Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Carrie D Nicora
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Angela D Norbeck
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Ljiljana Paša-Tolić
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Craig S Pikaard
- Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA Howard Hughes Medical Institute, Indiana University, Bloomington, IN 47405, USA
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Huang Y, Kendall T, Forsythe ES, Dorantes-Acosta A, Li S, Caballero-Pérez J, Chen X, Arteaga-Vázquez M, Beilstein MA, Mosher RA. Ancient Origin and Recent Innovations of RNA Polymerase IV and V. Mol Biol Evol 2015; 32:1788-99. [PMID: 25767205 PMCID: PMC4476159 DOI: 10.1093/molbev/msv060] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Small RNA-mediated chromatin modification is a conserved feature of eukaryotes. In flowering plants, the short interfering (si)RNAs that direct transcriptional silencing are abundant and subfunctionalization has led to specialized machinery responsible for synthesis and action of these small RNAs. In particular, plants possess polymerase (Pol) IV and Pol V, multi-subunit homologs of the canonical DNA-dependent RNA Pol II, as well as specialized members of the RNA-dependent RNA Polymerase (RDR), Dicer-like (DCL), and Argonaute (AGO) families. Together these enzymes are required for production and activity of Pol IV-dependent (p4-)siRNAs, which trigger RNA-directed DNA methylation (RdDM) at homologous sequences. p4-siRNAs accumulate highly in developing endosperm, a specialized tissue found only in flowering plants, and are rare in nonflowering plants, suggesting that the evolution of flowers might coincide with the emergence of specialized RdDM machinery. Through comprehensive identification of RdDM genes from species representing the breadth of the land plant phylogeny, we describe the ancient origin of Pol IV and Pol V, suggesting that a nearly complete and functional RdDM pathway could have existed in the earliest land plants. We also uncover innovations in these enzymes that are coincident with the emergence of seed plants and flowering plants, and recent duplications that might indicate additional subfunctionalization. Phylogenetic analysis reveals rapid evolution of Pol IV and Pol V subunits relative to their Pol II counterparts and suggests that duplicates were retained and subfunctionalized through Escape from Adaptive Conflict. Evolution within the carboxy-terminal domain of the Pol V largest subunit is particularly striking, where illegitimate recombination facilitated extreme sequence divergence.
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Affiliation(s)
- Yi Huang
- The School of Plant Sciences, The University of Arizona
| | - Timmy Kendall
- The School of Plant Sciences, The University of Arizona
| | | | - Ana Dorantes-Acosta
- Instituto de Biotecnología y Ecología Aplicada (INBIOTECA), Universidad Veracruzana, Veracruz, México
| | - Shaofang Li
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside
| | | | - Xuemei Chen
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside
| | - Mario Arteaga-Vázquez
- Instituto de Biotecnología y Ecología Aplicada (INBIOTECA), Universidad Veracruzana, Veracruz, México
| | | | - Rebecca A Mosher
- The School of Plant Sciences, The University of Arizona The Bio5 Institute, The University of Arizona
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Matzke MA, Kanno T, Matzke AJM. RNA-Directed DNA Methylation: The Evolution of a Complex Epigenetic Pathway in Flowering Plants. ANNUAL REVIEW OF PLANT BIOLOGY 2015; 66:243-67. [PMID: 25494460 DOI: 10.1146/annurev-arplant-043014-114633] [Citation(s) in RCA: 294] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
RNA-directed DNA methylation (RdDM) is an epigenetic process in plants that involves both short and long noncoding RNAs. The generation of these RNAs and the induction of RdDM rely on complex transcriptional machineries comprising two plant-specific, RNA polymerase II (Pol II)-related RNA polymerases known as Pol IV and Pol V, as well as a host of auxiliary factors that include both novel and refashioned proteins. We present current views on the mechanism of RdDM with a focus on evolutionary innovations that occurred during the transition from a Pol II transcriptional pathway, which produces mRNA precursors and numerous noncoding RNAs, to the Pol IV and Pol V pathways, which are specialized for RdDM and gene silencing. We describe recently recognized deviations from the canonical RdDM pathway, discuss unresolved issues, and speculate on the biological significance of RdDM for flowering plants, which have a highly developed Pol V pathway.
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Affiliation(s)
- Marjori A Matzke
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115, Taiwan; , ,
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15
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Abstract
The study of epigenetics in plants has a long and rich history, from initial descriptions of non-Mendelian gene behaviors to seminal discoveries of chromatin-modifying proteins and RNAs that mediate gene silencing in most eukaryotes, including humans. Genetic screens in the model plant Arabidopsis have been particularly rewarding, identifying more than 130 epigenetic regulators thus far. The diversity of epigenetic pathways in plants is remarkable, presumably contributing to the phenotypic plasticity of plant postembryonic development and the ability to survive and reproduce in unpredictable environments.
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Affiliation(s)
- Craig S Pikaard
- Department of Biology, Department of Molecular and Cellular Biochemistry, and Howard Hughes Medical Institute, Indiana University, Bloomington, Indiana 47405
| | - Ortrun Mittelsten Scheid
- Gregor Mendel-Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
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16
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Abstract
The study of epigenetics in plants has a long and rich history, from initial descriptions of non-Mendelian gene behaviors to seminal discoveries of chromatin-modifying proteins and RNAs that mediate gene silencing in most eukaryotes, including humans. Genetic screens in the model plant Arabidopsis have been particularly rewarding, identifying more than 130 epigenetic regulators thus far. The diversity of epigenetic pathways in plants is remarkable, presumably contributing to the phenotypic plasticity of plant postembryonic development and the ability to survive and reproduce in unpredictable environments.
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Affiliation(s)
- Craig S Pikaard
- Department of Biology, Department of Molecular and Cellular Biochemistry, and Howard Hughes Medical Institute, Indiana University, Bloomington, Indiana 47405
| | - Ortrun Mittelsten Scheid
- Gregor Mendel-Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
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17
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Functional diversification of maize RNA polymerase IV and V subtypes via alternative catalytic subunits. Cell Rep 2014; 9:378-390. [PMID: 25284785 DOI: 10.1016/j.celrep.2014.08.067] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/09/2014] [Accepted: 08/26/2014] [Indexed: 01/08/2023] Open
Abstract
Unlike nuclear multisubunit RNA polymerases I, II, and III, whose subunit compositions are conserved throughout eukaryotes, plant RNA polymerases IV and V are nonessential, Pol II-related enzymes whose subunit compositions are still evolving. Whereas Arabidopsis Pols IV and V differ from Pol II in four or five of their 12 subunits, respectively, and differ from one another in three subunits, proteomic analyses show that maize Pols IV and V differ from Pol II in six subunits but differ from each other only in their largest subunits. Use of alternative catalytic second subunits, which are nonredundant for development and paramutation, yields at least two subtypes of Pol IV and three subtypes of Pol V in maize. Pol IV/Pol V associations with MOP1, RMR1, AGO121, Zm_DRD1/CHR127, SHH2a, and SHH2b extend parallels between paramutation in maize and the RNA-directed DNA methylation pathway in Arabidopsis.
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18
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He XJ, Ma ZY, Liu ZW. Non-coding RNA transcription and RNA-directed DNA methylation in Arabidopsis. MOLECULAR PLANT 2014; 7:1406-1414. [PMID: 24966349 DOI: 10.1093/mp/ssu075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
RNA-directed DNA methylation (RdDM) is responsible for transcriptional silencing of endogenous transposable elements and introduced transgenes. This process requires non-coding RNAs produced by DNA-dependent RNA polymerases IV and V (Pol IV and Pol V). Pol IV-produced non-coding RNAs are precursors of 24-nt small interfering RNAs, whereas Pol V-produced ncRNAs directly act as scaffold RNAs. In this review, we summarize recent advances in the understanding of RdDM. In particular, we focus on the mechanisms underlying the recruitment of Pol IV and Pol V to chromatin and the targeting of RdDM.
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Affiliation(s)
- Xin-Jian He
- National Institute of Biological Sciences, Beijing 102206, China.
| | - Ze-Yang Ma
- National Institute of Biological Sciences, Beijing 102206, China
| | - Zhang-Wei Liu
- National Institute of Biological Sciences, Beijing 102206, China
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19
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Abstract
RNA-directed DNA methylation (RdDM) is the major small RNA-mediated epigenetic pathway in plants. RdDM requires a specialized transcriptional machinery that comprises two plant-specific RNA polymerases - Pol IV and Pol V - and a growing number of accessory proteins, the functions of which in the RdDM mechanism are only partially understood. Recent work has revealed variations in the canonical RdDM pathway and identified factors that recruit Pol IV and Pol V to specific target sequences. RdDM, which transcriptionally represses a subset of transposons and genes, is implicated in pathogen defence, stress responses and reproduction, as well as in interallelic and intercellular communication.
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20
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Knutson BA. Emergence and expansion of TFIIB-like factors in the plant kingdom. Gene 2013; 526:30-8. [PMID: 23608173 DOI: 10.1016/j.gene.2013.04.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 03/29/2013] [Accepted: 04/01/2013] [Indexed: 11/27/2022]
Abstract
Many gene families in higher plants have expanded in number, giving rise to diverse protein paralogs with specialized biochemical functions. For instance, plant general transcription factors such as TFIIB have expanded in number and in some cases perform specialized transcriptional functions in the plant cell. To date, no comprehensive genome-wide identification of the TFIIB gene family has been conducted in the plant kingdom. To determine the extent of TFIIB expansion in plants, I used the remote homology program HHPred to search for TFIIB homologs in the plant kingdom and performed a comprehensive analysis of eukaryotic TFIIB gene families. I discovered that higher plants encode more than 10 different TFIIB-like proteins. In particular, Arabidopsis thaliana encodes 14 different TFIIB-like proteins and predicted domain architectures of the newly identified TFIIB-like proteins revealed that they have unique modular domain structures that are divergent in sequence and size. Phylogenetic analysis of selected eukaryotic organisms showed that most life forms encode three major TFIIB subfamilies that include TFIIB, Brf, Rrn7/TAF1B/MEE12 subfamilies, while all plants and some algae species encode one or two additional TFIIB-related protein subfamilies. A subset of A. thaliana GTFs have also expanded in number, indicating that GTF diversification and expansion is a general phenomenon in higher plants. Together, these findings were used to generate a model for the evolutionary history of TFIIB-like proteins in eukaryotes.
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Affiliation(s)
- Bruce A Knutson
- Fred Hutchinson Cancer Research Center, Division of Basic Sciences, 1100 Fairview Ave N, PO Box 19024, Mailstop A1-162, Seattle, WA 98109, USA.
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21
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Havecker ER, Wallbridge LM, Fedito P, Hardcastle TJ, Baulcombe DC. Metastable differentially methylated regions within Arabidopsis inbred populations are associated with modified expression of non-coding transcripts. PLoS One 2012; 7:e45242. [PMID: 23028873 PMCID: PMC3447930 DOI: 10.1371/journal.pone.0045242] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Accepted: 08/17/2012] [Indexed: 01/26/2023] Open
Abstract
Individual plants within a population may vary at both genetic and epigenetic levels. The rate of genetic divergence and its underlying mechanisms is well understood. Less is known about the factors contributing to epigenetic divergence among isogenic populations except that, despite the presence of mechanisms that faithfully maintain epigenetic marks, epigenetic differences are more frequent than genetic variation. Epigenetically divergent stretches of isogenic DNA sequence are called epialleles. Currently, it is not clear why certain regions exhibit variable epigenetic status. We identified and characterised two long RNA transcripts with altered expression and DNA methylation in an ago5 mutant. However, further investigation revealed that these changes were not dependent upon AGO5. Rather, the variable transcription of these loci in Arabidopsis mutant and wild-type populations corresponds to spontaneous differential methylated regions (DMRs) or epialleles. These two DMRs are delineated by RNAs which are highly expressed when the DMR is hypomethylated. Furthermore, they control the expression of 5′ transcriptional start site mRNA variants of nearby protein coding genes. Our data support the recent observations that meiotically stable DMRs exist within inbred populations. We further demonstrate that DMR boundaries can be defined by putative non-coding promoter-associated transcripts.
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Affiliation(s)
- Ericka R. Havecker
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Laura M. Wallbridge
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Paola Fedito
- BIOMAA, University Mediterranea of Reggio Calabria, Reggio Calabria, Italy
| | - Thomas J. Hardcastle
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - David C. Baulcombe
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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