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Amiard S, Feit L, Vanrobays E, Simon L, Le Goff S, Loizeau L, Wolff L, Butter F, Bourbousse C, Barneche F, Tatout C, Probst AV. The TELOMERE REPEAT BINDING proteins TRB4 and TRB5 function as transcriptional activators of PRC2-controlled genes to regulate plant development. PLANT COMMUNICATIONS 2024; 5:100890. [PMID: 38566416 DOI: 10.1016/j.xplc.2024.100890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 02/07/2024] [Accepted: 03/29/2024] [Indexed: 04/04/2024]
Abstract
Plant-specific transcriptional regulators called TELOMERE REPEAT BINDING proteins (TRBs) combine two DNA-binding domains, the GH1 domain, which binds to linker DNA and is shared with H1 histones, and the Myb/SANT domain, which specifically recognizes the telobox DNA-binding site motif. TRB1, TRB2, and TRB3 proteins recruit Polycomb group complex 2 (PRC2) to deposit H3K27me3 and JMJ14 to remove H3K4me3 at gene promoters containing telobox motifs to repress transcription. Here, we demonstrate that TRB4 and TRB5, two related paralogs belonging to a separate TRB clade conserved in spermatophytes, regulate the transcription of several hundred genes involved in developmental responses to environmental cues. TRB4 binds to several thousand sites in the genome, mainly at transcription start sites and promoter regions of transcriptionally active and H3K4me3-marked genes, but, unlike TRB1, it is not enriched at H3K27me3-marked gene bodies. However, TRB4 can physically interact with the catalytic components of PRC2, SWINGER, and CURLY LEAF (CLF). Unexpectedly, we show that TRB4 and TRB5 are required for distinctive phenotypic traits observed in clf mutant plants and thus function as transcriptional activators of several hundred CLF-controlled genes, including key flowering genes. We further demonstrate that TRB4 shares multiple target genes with TRB1 and physically and genetically interacts with members of both TRB clades. Collectively, these results reveal that TRB proteins engage in both positive and negative interactions with other members of the family to regulate plant development through both PRC2-dependent and -independent mechanisms.
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Affiliation(s)
- Simon Amiard
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000 Clermont-Ferrand, France.
| | - Léa Feit
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Emmanuel Vanrobays
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Lauriane Simon
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Samuel Le Goff
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Loriane Loizeau
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Léa Wolff
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Falk Butter
- Institute of Molecular Biology, 55128 Mainz, Germany
| | - Clara Bourbousse
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Fredy Barneche
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Christophe Tatout
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Aline V Probst
- iGReD, CNRS, Inserm, Université Clermont Auvergne, 63000 Clermont-Ferrand, France.
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2
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Davis JA, Chakrabarti K. Molecular and Evolutionary Analysis of RNA-Protein Interactions in Telomerase Regulation. Noncoding RNA 2024; 10:36. [PMID: 38921833 PMCID: PMC11206666 DOI: 10.3390/ncrna10030036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 05/30/2024] [Accepted: 06/10/2024] [Indexed: 06/27/2024] Open
Abstract
Telomerase is an enzyme involved in the maintenance of telomeres. Telomere shortening due to the end-replication problem is a threat to the genome integrity of all eukaryotes. Telomerase inside cells depends on a myriad of protein-protein and RNA-protein interactions to properly assemble and regulate the function of the telomerase holoenzyme. These interactions are well studied in model eukaryotes, like humans, yeast, and the ciliated protozoan known as Tetrahymena thermophila. Emerging evidence also suggests that deep-branching eukaryotes, such as the parasitic protist Trypanosoma brucei require conserved and novel RNA-binding proteins for the assembly and function of their telomerase. In this review, we will discuss telomerase regulatory pathways in the context of telomerase-interacting proteins, with special attention paid to RNA-binding proteins. We will discuss these interactors on an evolutionary scale, from parasitic protists to humans, to provide a broader perspective on the extensive role that protein-protein and RNA-protein interactions play in regulating telomerase activity in eukaryotes.
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Affiliation(s)
| | - Kausik Chakrabarti
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA;
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3
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Zheng SY, Guan BB, Yuan DY, Zhao QQ, Ge W, Tan LM, Chen SS, Li L, Chen S, Xu RM, He XJ. Dual roles of the Arabidopsis PEAT complex in histone H2A deubiquitination and H4K5 acetylation. MOLECULAR PLANT 2023; 16:1847-1865. [PMID: 37822080 DOI: 10.1016/j.molp.2023.10.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 09/06/2023] [Accepted: 10/08/2023] [Indexed: 10/13/2023]
Abstract
Histone H2A monoubiquitination is associated with transcriptional repression and needs to be removed by deubiquitinases to facilitate gene transcription in eukaryotes. However, the deubiquitinase responsible for genome-wide H2A deubiquitination in plants has yet to be identified. In this study, we found that the previously identified PWWP-EPCR-ARID-TRB (PEAT) complex components interact with both the ubiquitin-specific protease UBP5 and the redundant histone acetyltransferases HAM1 and HAM2 (HAM1/2) to form a larger version of PEAT complex in Arabidopsis thaliana. UBP5 functions as an H2A deubiquitinase in a nucleosome substrate-dependent manner in vitro and mediates H2A deubiquitination at the whole-genome level in vivo. HAM1/2 are shared subunits of the PEAT complex and the conserved NuA4 histone acetyltransferase complex, and are responsible for histone H4K5 acetylation. Within the PEAT complex, the PWWP components (PWWP1, PWWP2, and PWWP3) directly interact with UBP5 and are necessary for UBP5-mediated H2A deubiquitination, while the EPCR components (EPCR1 and EPCR2) directly interact with HAM1/2 and are required for HAM1/2-mediated H4K5 acetylation. Collectively, our study not only identifies dual roles of the PEAT complex in H2A deubiquitination and H4K5 acetylation but also illustrates how these processes collaborate at the whole-genome level to regulate the transcription and development in plants.
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Affiliation(s)
- Si-Yao Zheng
- College of Life Sciences, Beijing Normal University, Beijing, China; National Institute of Biological Sciences, Beijing, China
| | - Bin-Bin Guan
- National Institute of Biological Sciences, Beijing, China
| | - Dan-Yang Yuan
- National Institute of Biological Sciences, Beijing, China
| | | | - Weiran Ge
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; School of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Lian-Mei Tan
- National Institute of Biological Sciences, Beijing, China
| | - Shan-Shan Chen
- National Institute of Biological Sciences, Beijing, China
| | - Lin Li
- National Institute of Biological Sciences, Beijing, China
| | - She Chen
- National Institute of Biological Sciences, Beijing, China
| | - Rui-Ming Xu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; School of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xin-Jian He
- National Institute of Biological Sciences, Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China.
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4
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Teano G, Concia L, Wolff L, Carron L, Biocanin I, Adamusová K, Fojtová M, Bourge M, Kramdi A, Colot V, Grossniklaus U, Bowler C, Baroux C, Carbone A, Probst AV, Schrumpfová PP, Fajkus J, Amiard S, Grob S, Bourbousse C, Barneche F. Histone H1 protects telomeric repeats from H3K27me3 invasion in Arabidopsis. Cell Rep 2023; 42:112894. [PMID: 37515769 DOI: 10.1016/j.celrep.2023.112894] [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: 01/21/2021] [Revised: 12/02/2022] [Accepted: 07/13/2023] [Indexed: 07/31/2023] Open
Abstract
While the pivotal role of linker histone H1 in shaping nucleosome organization is well established, its functional interplays with chromatin factors along the epigenome are just starting to emerge. Here we show that, in Arabidopsis, as in mammals, H1 occupies Polycomb Repressive Complex 2 (PRC2) target genes where it favors chromatin condensation and H3K27me3 deposition. We further show that, contrasting with its conserved function in PRC2 activation at genes, H1 selectively prevents H3K27me3 accumulation at telomeres and large pericentromeric interstitial telomeric repeat (ITR) domains by restricting DNA accessibility to Telomere Repeat Binding (TRB) proteins, a group of H1-related Myb factors mediating PRC2 cis recruitment. This study provides a mechanistic framework by which H1 avoids the formation of gigantic H3K27me3-rich domains at telomeric sequences and contributes to safeguard nucleus architecture.
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Affiliation(s)
- Gianluca Teano
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, France; Université Paris-Saclay, 91190 Orsay, France
| | - Lorenzo Concia
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Léa Wolff
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Léopold Carron
- Sorbonne Université, CNRS, IBPS, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
| | - Ivona Biocanin
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, France; Université Paris-Saclay, 91190 Orsay, France
| | - Kateřina Adamusová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czech Republic; Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czech Republic; Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Michael Bourge
- Cytometry Facility, Imagerie-Gif, Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Amira Kramdi
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Vincent Colot
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Chris Bowler
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Célia Baroux
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Alessandra Carbone
- Sorbonne Université, CNRS, IBPS, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
| | - Aline V Probst
- CNRS UMR6293, Université Clermont Auvergne, INSERM U1103, GReD, CRBC, Clermont-Ferrand, France
| | - Petra Procházková Schrumpfová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czech Republic; Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czech Republic; Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Simon Amiard
- CNRS UMR6293, Université Clermont Auvergne, INSERM U1103, GReD, CRBC, Clermont-Ferrand, France
| | - Stefan Grob
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Clara Bourbousse
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Fredy Barneche
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris, France.
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5
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Kusová A, Steinbachová L, Přerovská T, Drábková LZ, Paleček J, Khan A, Rigóová G, Gadiou Z, Jourdain C, Stricker T, Schubert D, Honys D, Schrumpfová PP. Completing the TRB family: newly characterized members show ancient evolutionary origins and distinct localization, yet similar interactions. PLANT MOLECULAR BIOLOGY 2023; 112:61-83. [PMID: 37118559 PMCID: PMC10167121 DOI: 10.1007/s11103-023-01348-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/02/2023] [Indexed: 05/09/2023]
Abstract
Telomere repeat binding proteins (TRBs) belong to a family of proteins possessing a Myb-like domain which binds to telomeric repeats. Three members of this family (TRB1, TRB2, TRB3) from Arabidopsis thaliana have already been described as associated with terminal telomeric repeats (telomeres) or short interstitial telomeric repeats in gene promoters (telo-boxes). They are also known to interact with several protein complexes: telomerase, Polycomb repressive complex 2 (PRC2) E(z) subunits and the PEAT complex (PWOs-EPCRs-ARIDs-TRBs). Here we characterize two novel members of the TRB family (TRB4 and TRB5). Our wide phylogenetic analyses have shown that TRB proteins evolved in the plant kingdom after the transition to a terrestrial habitat in Streptophyta, and consequently TRBs diversified in seed plants. TRB4-5 share common TRB motifs while differing in several others and seem to have an earlier phylogenetic origin than TRB1-3. Their common Myb-like domains bind long arrays of telomeric repeats in vitro, and we have determined the minimal recognition motif of all TRBs as one telo-box. Our data indicate that despite the distinct localization patterns of TRB1-3 and TRB4-5 in situ, all members of TRB family mutually interact and also bind to telomerase/PRC2/PEAT complexes. Additionally, we have detected novel interactions between TRB4-5 and EMF2 and VRN2, which are Su(z)12 subunits of PRC2.
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Affiliation(s)
- Alžbeta Kusová
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Lenka Steinbachová
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Tereza Přerovská
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
| | - Lenka Záveská Drábková
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Paleček
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Ahamed Khan
- Institute of Plant Molecular Biology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Gabriela Rigóová
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
| | - Zuzana Gadiou
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Claire Jourdain
- Institute of Biology, Freie Universität Berlin, 14195, Berlin, Germany
| | - Tino Stricker
- Institute of Biology, Freie Universität Berlin, 14195, Berlin, Germany
| | - Daniel Schubert
- Institute of Biology, Freie Universität Berlin, 14195, Berlin, Germany
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Petra Procházková Schrumpfová
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic.
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
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6
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Wang M, Zhong Z, Gallego-Bartolomé J, Feng S, Shih YH, Liu M, Zhou J, Richey JC, Ng C, Jami-Alahmadi Y, Wohlschlegel J, Wu K, Jacobsen SE. Arabidopsis TRB proteins function in H3K4me3 demethylation by recruiting JMJ14. Nat Commun 2023; 14:1736. [PMID: 36977663 PMCID: PMC10049986 DOI: 10.1038/s41467-023-37263-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 03/06/2023] [Indexed: 03/30/2023] Open
Abstract
Arabidopsis telomeric repeat binding factors (TRBs) can bind telomeric DNA sequences to protect telomeres from degradation. TRBs can also recruit Polycomb Repressive Complex 2 (PRC2) to deposit tri-methylation of H3 lysine 27 (H3K27me3) over certain target loci. Here, we demonstrate that TRBs also associate and colocalize with JUMONJI14 (JMJ14) and trigger H3K4me3 demethylation at some loci. The trb1/2/3 triple mutant and the jmj14-1 mutant show an increased level of H3K4me3 over TRB and JMJ14 binding sites, resulting in up-regulation of their target genes. Furthermore, tethering TRBs to the promoter region of genes with an artificial zinc finger (TRB-ZF) successfully triggers target gene silencing, as well as H3K27me3 deposition, and H3K4me3 removal. Interestingly, JMJ14 is predominantly recruited to ZF off-target sites with low levels of H3K4me3, which is accompanied with TRB-ZFs triggered H3K4me3 removal at these loci. These results suggest that TRB proteins coordinate PRC2 and JMJ14 activities to repress target genes via H3K27me3 deposition and H3K4me3 removal.
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Affiliation(s)
- Ming Wang
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Zhenhui Zhong
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Javier Gallego-Bartolomé
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, 46022, Valencia, Spain
| | - Suhua Feng
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
- Eli & Edythe Broad Center of Regenerative Medicine & Stem Cell Research, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Yuan-Hsin Shih
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
- Institute of Plant Biology, National Taiwan University, Taipei, 10617, Taiwan
| | - Mukun Liu
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Jessica Zhou
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - John Curtis Richey
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Charmaine Ng
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - James Wohlschlegel
- Department of Biological Chemistry, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Keqiang Wu
- Institute of Plant Biology, National Taiwan University, Taipei, 10617, Taiwan
| | - Steven E Jacobsen
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, 90095, USA.
- Eli & Edythe Broad Center of Regenerative Medicine & Stem Cell Research, University of California at Los Angeles, Los Angeles, CA, 90095, USA.
- Department of Biological Chemistry, University of California at Los Angeles, Los Angeles, CA, 90095, USA.
- Howard Hughes Medical Institute (HHMI), University of California at Los Angeles, Los Angeles, CA, 90095, USA.
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7
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Telomeres and Their Neighbors. Genes (Basel) 2022; 13:genes13091663. [PMID: 36140830 PMCID: PMC9498494 DOI: 10.3390/genes13091663] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 11/21/2022] Open
Abstract
Telomeres are essential structures formed from satellite DNA repeats at the ends of chromosomes in most eukaryotes. Satellite DNA repeat sequences are useful markers for karyotyping, but have a more enigmatic role in the eukaryotic cell. Much work has been done to investigate the structure and arrangement of repetitive DNA elements in classical models with implications for species evolution. Still more is needed until there is a complete picture of the biological function of DNA satellite sequences, particularly when considering non-model organisms. Celebrating Gregor Mendel’s anniversary by going to the roots, this review is designed to inspire and aid new research into telomeres and satellites with a particular focus on non-model organisms and accessible experimental and in silico methods that do not require specialized equipment or expensive materials. We describe how to identify telomere (and satellite) repeats giving many examples of published (and some unpublished) data from these techniques to illustrate the principles behind the experiments. We also present advice on how to perform and analyse such experiments, including details of common pitfalls. Our examples are a selection of recent developments and underexplored areas of research from the past. As a nod to Mendel’s early work, we use many examples from plants and insects, especially as much recent work has expanded beyond the human and yeast models traditional in telomere research. We give a general introduction to the accepted knowledge of telomere and satellite systems and include references to specialized reviews for the interested reader.
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8
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Rahmani RS, Decap D, Fostier J, Marchal K. BLSSpeller to discover novel regulatory motifs in maize. DNA Res 2022; 29:6651838. [PMID: 35904558 PMCID: PMC9358016 DOI: 10.1093/dnares/dsac029] [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: 02/18/2022] [Indexed: 11/13/2022] Open
Abstract
Abstract
With the decreasing cost of sequencing and availability of larger numbers of sequenced genomes, comparative genomics is becoming increasingly attractive to complement experimental techniques for the task of transcription factor (TF) binding site identification. In this study, we redesigned BLSSpeller, a motif discovery algorithm, to cope with larger sequence datasets. BLSSpeller was used to identify novel motifs in Zea mays in a comparative genomics setting with 16 monocot lineages. We discovered 61 motifs of which 20 matched previously described motif models in Arabidopsis. In addition, novel, yet uncharacterized motifs were detected, several of which are supported by available sequence-based and/or functional data. Instances of the predicted motifs were enriched around transcription start sites and contained signatures of selection. Moreover, the enrichment of the predicted motif instances in open chromatin and TF binding sites indicates their functionality, supported by the fact that genes carrying instances of these motifs were often found to be co-expressed and/or enriched in similar GO functions. Overall, our study unveiled several novel candidate motifs that might help our understanding of the genotype to phenotype association in crops.
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Affiliation(s)
- Razgar Seyed Rahmani
- Department of Plant Biotechnology and Bioinformatics, Ghent University , Gent, Belgium
- Department of Information Technology, IDLab, Ghent University—imec , Gent, Belgium
| | - Dries Decap
- Department of Information Technology, IDLab, Ghent University—imec , Gent, Belgium
| | - Jan Fostier
- Department of Information Technology, IDLab, Ghent University—imec , Gent, Belgium
| | - Kathleen Marchal
- Department of Plant Biotechnology and Bioinformatics, Ghent University , Gent, Belgium
- Department of Information Technology, IDLab, Ghent University—imec , Gent, Belgium
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria , Pretoria, South Africa
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9
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Koskimäki JJ, Pohjanen J, Kvist J, Fester T, Härtig C, Podolich O, Fluch S, Edesi J, Häggman H, Pirttilä AM. The meristem-associated endosymbiont Methylorubrum extorquens DSM13060 reprograms development and stress responses of pine seedlings. TREE PHYSIOLOGY 2022; 42:391-410. [PMID: 34328183 PMCID: PMC8842435 DOI: 10.1093/treephys/tpab102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
Microbes living in plant tissues-endophytes-are mainly studied in crop plants where they typically colonize the root apoplast. Trees-a large carbon source with a high capacity for photosynthesis-provide a variety of niches for endophytic colonization. We have earlier identified a new type of plant-endophyte interaction in buds of adult Scots pine, where Methylorubrum species live inside the meristematic cells. The endosymbiont Methylorubrum extorquens DSM13060 significantly increases needle and root growth of pine seedlings without producing plant hormones, but by aggregating around host nuclei. Here, we studied gene expression and metabolites of the pine host induced by M. extorquens DSM13060 infection. Malic acid was produced by pine to potentially boost M. extorquens colonization and interaction. Based on gene expression, the endosymbiont activated the auxin- and ethylene (ET)-associated hormonal pathways through induction of CUL1 and HYL1, and suppressed salicylic and abscisic acid signaling of pine. Infection by the endosymbiont had an effect on pine meristem and leaf development through activation of GLP1-7 and ALE2, and suppressed flowering, root hair and lateral root formation by downregulation of AGL8, plantacyanin, GASA7, COW1 and RALFL34. Despite of systemic infection of pine seedlings by the endosymbiont, the pine genes CUL1, ETR2, ERF3, HYL, GLP1-7 and CYP71 were highly expressed in the shoot apical meristem, rarely in needles and not in stem or root tissues. Low expression of MERI5, CLH2, EULS3 and high quantities of ononitol suggest that endosymbiont promotes viability and protects pine seedlings against abiotic stress. Our results indicate that the endosymbiont positively affects host development and stress tolerance through mechanisms previously unknown for endophytic bacteria, manipulation of plant hormone signaling pathways, downregulation of senescence and cell death-associated genes and induction of ononitol biosynthesis.
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Affiliation(s)
- Janne J Koskimäki
- Ecology and Genetics Research Unit, University of Oulu, Paavo Havaksentie J1, FI-90014 Oulu, Finland
| | - Johanna Pohjanen
- Ecology and Genetics Research Unit, University of Oulu, Paavo Havaksentie J1, FI-90014 Oulu, Finland
| | - Jouni Kvist
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Haartmaninkatu 8, FI-00014 Helsinki, Finland
| | - Thomas Fester
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research – UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Claus Härtig
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research – UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Olga Podolich
- Institute of Molecular Biology and Genetics of NASU, Acad. Zabolotnoho str., 150 03680 Kyiv, Ukraine
| | | | - Jaanika Edesi
- Ecology and Genetics Research Unit, University of Oulu, Paavo Havaksentie J1, FI-90014 Oulu, Finland
- Production Systems, Tree Breeding, Natural Resources Institute Finland LUKE, FI-57200 Savonlinna, Finland
| | - Hely Häggman
- Ecology and Genetics Research Unit, University of Oulu, Paavo Havaksentie J1, FI-90014 Oulu, Finland
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10
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Vijayanathan M, Trejo-Arellano MG, Mozgová I. Polycomb Repressive Complex 2 in Eukaryotes-An Evolutionary Perspective. EPIGENOMES 2022; 6:3. [PMID: 35076495 PMCID: PMC8788455 DOI: 10.3390/epigenomes6010003] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/12/2022] [Accepted: 01/12/2022] [Indexed: 12/23/2022] Open
Abstract
Polycomb repressive complex 2 (PRC2) represents a group of evolutionarily conserved multi-subunit complexes that repress gene transcription by introducing trimethylation of lysine 27 on histone 3 (H3K27me3). PRC2 activity is of key importance for cell identity specification and developmental phase transitions in animals and plants. The composition, biochemistry, and developmental function of PRC2 in animal and flowering plant model species are relatively well described. Recent evidence demonstrates the presence of PRC2 complexes in various eukaryotic supergroups, suggesting conservation of the complex and its function. Here, we provide an overview of the current understanding of PRC2-mediated repression in different representatives of eukaryotic supergroups with a focus on the green lineage. By comparison of PRC2 in different eukaryotes, we highlight the possible common and diverged features suggesting evolutionary implications and outline emerging questions and directions for future research of polycomb repression and its evolution.
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Affiliation(s)
- Mallika Vijayanathan
- Biology Centre, Institute of Plant Molecular Biology, Czech Academy of Sciences, 370 05 Ceske Budejovice, Czech Republic; (M.V.); (M.G.T.-A.)
| | - María Guadalupe Trejo-Arellano
- Biology Centre, Institute of Plant Molecular Biology, Czech Academy of Sciences, 370 05 Ceske Budejovice, Czech Republic; (M.V.); (M.G.T.-A.)
| | - Iva Mozgová
- Biology Centre, Institute of Plant Molecular Biology, Czech Academy of Sciences, 370 05 Ceske Budejovice, Czech Republic; (M.V.); (M.G.T.-A.)
- Faculty of Science, University of South Bohemia, 370 05 Ceske Budejovice, Czech Republic
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11
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Telomerase Interaction Partners-Insight from Plants. Int J Mol Sci 2021; 23:ijms23010368. [PMID: 35008793 PMCID: PMC8745574 DOI: 10.3390/ijms23010368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/26/2021] [Accepted: 12/27/2021] [Indexed: 12/29/2022] Open
Abstract
Telomerase, an essential enzyme that maintains chromosome ends, is important for genome integrity and organism development. Various hypotheses have been proposed in human, ciliate and yeast systems to explain the coordination of telomerase holoenzyme assembly and the timing of telomerase performance at telomeres during DNA replication or repair. However, a general model is still unclear, especially pathways connecting telomerase with proposed non-telomeric functions. To strengthen our understanding of telomerase function during its intracellular life, we report on interactions of several groups of proteins with the Arabidopsis telomerase protein subunit (AtTERT) and/or a component of telomerase holoenzyme, POT1a protein. Among these are the nucleosome assembly proteins (NAP) and the minichromosome maintenance (MCM) system, which reveal new insights into the telomerase interaction network with links to telomere chromatin assembly and replication. A targeted investigation of 176 candidate proteins demonstrated numerous interactions with nucleolar, transport and ribosomal proteins, as well as molecular chaperones, shedding light on interactions during telomerase biogenesis. We further identified protein domains responsible for binding and analyzed the subcellular localization of these interactions. Moreover, additional interaction networks of NAP proteins and the DOMINO1 protein were identified. Our data support an image of functional telomerase contacts with multiprotein complexes including chromatin remodeling and cell differentiation pathways.
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12
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Watson JM, Trieb J, Troestl M, Renfrew K, Mandakova T, Fulnecek J, Shippen DE, Riha K. A hypomorphic allele of telomerase uncovers the minimal functional length of telomeres in Arabidopsis. Genetics 2021; 219:6339584. [PMID: 34849882 DOI: 10.1093/genetics/iyab126] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 07/23/2021] [Indexed: 12/23/2022] Open
Abstract
Despite the essential requirement of telomeric DNA for genome stability, the length of telomere tracts between species substantially differs, raising the question of the minimal length of telomeric DNA necessary for proper function. Here, we address this question using a hypomorphic allele of the telomerase catalytic subunit, TERT. We show that although this construct partially restored telomerase activity to a tert mutant, telomeres continued to shorten over several generations, ultimately stabilizing at a bimodal size distribution. Telomeres on two chromosome arms were maintained at a length of 1 kb, while the remaining telomeres were maintained at 400 bp. The longest telomeres identified in this background were also significantly longer in wild-type populations, suggesting cis-acting elements on these arms either promote telomerase processivity or recruitment. Genetically disrupting telomerase processivity in this background resulted in immediate lethality. Thus, telomeres of 400 bp are both necessary and sufficient for Arabidopsis viability. As this length is the estimated minimal length for t-loop formation, our data suggest that telomeres long enough to form a t-loop constitute the minimal functional length.
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Affiliation(s)
- J Matthew Watson
- Gregor Mendel Institute of Plant Molecular Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Johanna Trieb
- Gregor Mendel Institute of Plant Molecular Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Martina Troestl
- Gregor Mendel Institute of Plant Molecular Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Kyle Renfrew
- Department of Biochemistry, Texas A&M University, College Station, TX 77840, USA
| | - Terezie Mandakova
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Jaroslav Fulnecek
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Dorothy E Shippen
- Department of Biochemistry, Texas A&M University, College Station, TX 77840, USA
| | - Karel Riha
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
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13
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An JP, Xu RR, Liu X, Zhang JC, Wang XF, You CX, Hao YJ. Jasmonate induces biosynthesis of anthocyanin and proanthocyanidin in apple by mediating the JAZ1-TRB1-MYB9 complex. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1414-1430. [PMID: 33759251 DOI: 10.1111/tpj.15245] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/13/2021] [Accepted: 03/16/2021] [Indexed: 05/15/2023]
Abstract
Jasmonate (JA) induces the biosynthesis of anthocyanin and proanthocyanidin. MdMYB9 is essential for modulating the accumulation of both anthocyanin and proanthocyanidin in apple, but the molecular mechanism for induction of anthocyanin and proanthocyanidin biosynthesis by JA is unclear. In this study, we discovered an apple telomere-binding protein (MdTRB1) to be the interacting protein of MdMYB9. A series of biological assays showed that MdTRB1 acted as a positive modulator of anthocyanin and proanthocyanidin accumulation, and is dependent on MdMYB9. MdTRB1 interacted with MdMYB9 and enhanced the activation activity of MdMYB9 to its downstream genes. In addition, we found that the JA signaling repressor MdJAZ1 interacted with MdTRB1 and interfered with the interaction between MdTRB1 and MdMYB9, therefore negatively modulating MdTRB1-promoted biosynthesis of anthocyanin and proanthocyanidin. These results show that the JAZ1-TRB1-MYB9 module dynamically modulates JA-mediated accumulation of anthocyanin and proanthocyanidin. Taken together, our data further expand the functional study of TRB1 and provide insights for further studies of the modulation of anthocyanin and proanthocyanidin biosynthesis by JA.
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Affiliation(s)
- Jian-Ping An
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center for Fruit and Vegetable Production with High Quality and Efficiency, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, 271018, China
| | - Rui-Rui Xu
- Key Laboratory of Biochemistry and Molecular Biology in Universities of Shandong, College of Biological and Agricultural Engineering, Weifang University, Weifang, Shandong, 261061, China
| | - Xin Liu
- Beijing Academy of Forestry and Pomology Sciences, Beijing, 100093, China
| | - Jiu-Cheng Zhang
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center for Fruit and Vegetable Production with High Quality and Efficiency, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, 271018, China
| | - Xiao-Fei Wang
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center for Fruit and Vegetable Production with High Quality and Efficiency, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, 271018, China
| | - Chun-Xiang You
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center for Fruit and Vegetable Production with High Quality and Efficiency, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, 271018, China
| | - Yu-Jin Hao
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center for Fruit and Vegetable Production with High Quality and Efficiency, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, 271018, China
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14
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Aguilar M, Prieto P. Telomeres and Subtelomeres Dynamics in the Context of Early Chromosome Interactions During Meiosis and Their Implications in Plant Breeding. FRONTIERS IN PLANT SCIENCE 2021; 12:672489. [PMID: 34149773 PMCID: PMC8212018 DOI: 10.3389/fpls.2021.672489] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/06/2021] [Indexed: 05/08/2023]
Abstract
Genomic architecture facilitates chromosome recognition, pairing, and recombination. Telomeres and subtelomeres play an important role at the beginning of meiosis in specific chromosome recognition and pairing, which are critical processes that allow chromosome recombination between homologs (equivalent chromosomes in the same genome) in later stages. In plant polyploids, these terminal regions are even more important in terms of homologous chromosome recognition, due to the presence of homoeologs (equivalent chromosomes from related genomes). Although telomeres interaction seems to assist homologous pairing and consequently, the progression of meiosis, other chromosome regions, such as subtelomeres, need to be considered, because the DNA sequence of telomeres is not chromosome-specific. In addition, recombination operates at subtelomeres and, as it happens in rye and wheat, homologous recognition and pairing is more often correlated with recombining regions than with crossover-poor regions. In a plant breeding context, the knowledge of how homologous chromosomes initiate pairing at the beginning of meiosis can contribute to chromosome manipulation in hybrids or interspecific genetic crosses. Thus, recombination in interspecific chromosome associations could be promoted with the aim of transferring desirable agronomic traits from related genetic donor species into crops. In this review, we summarize the importance of telomeres and subtelomeres on chromatin dynamics during early meiosis stages and their implications in recombination in a plant breeding framework.
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Affiliation(s)
- Miguel Aguilar
- Área de Fisiología Vegetal, Universidad de Córdoba, Córdoba, Spain
| | - Pilar Prieto
- Plant Breeding Department, Institute for Sustainable Agriculture, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Córdoba, Spain
- *Correspondence: Pilar Prieto, ; orcid.org/0000-0002-8160-808X
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15
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Schrumpfová PP, Fajkus J. Composition and Function of Telomerase-A Polymerase Associated with the Origin of Eukaryotes. Biomolecules 2020; 10:biom10101425. [PMID: 33050064 PMCID: PMC7658794 DOI: 10.3390/biom10101425] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 12/19/2022] Open
Abstract
The canonical DNA polymerases involved in the replication of the genome are unable to fully replicate the physical ends of linear chromosomes, called telomeres. Chromosomal termini thus become shortened in each cell cycle. The maintenance of telomeres requires telomerase—a specific RNA-dependent DNA polymerase enzyme complex that carries its own RNA template and adds telomeric repeats to the ends of chromosomes using a reverse transcription mechanism. Both core subunits of telomerase—its catalytic telomerase reverse transcriptase (TERT) subunit and telomerase RNA (TR) component—were identified in quick succession in Tetrahymena more than 30 years ago. Since then, both telomerase subunits have been described in various organisms including yeasts, mammals, birds, reptiles and fish. Despite the fact that telomerase activity in plants was described 25 years ago and the TERT subunit four years later, a genuine plant TR has only recently been identified by our group. In this review, we focus on the structure, composition and function of telomerases. In addition, we discuss the origin and phylogenetic divergence of this unique RNA-dependent DNA polymerase as a witness of early eukaryotic evolution. Specifically, we discuss the latest information regarding the recently discovered TR component in plants, its conservation and its structural features.
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Affiliation(s)
- Petra Procházková Schrumpfová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic;
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
- Correspondence:
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic;
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
- The Czech Academy of Sciences, Institute of Biophysics, Královopolská 135, 612 65 Brno, Czech Republic
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16
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Khosravi S, Schindele P, Gladilin E, Dunemann F, Rutten T, Puchta H, Houben A. Application of Aptamers Improves CRISPR-Based Live Imaging of Plant Telomeres. FRONTIERS IN PLANT SCIENCE 2020; 11:1254. [PMID: 32973827 PMCID: PMC7468473 DOI: 10.3389/fpls.2020.01254] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/30/2020] [Indexed: 06/01/2023]
Abstract
Development of live imaging techniques for providing information how chromatin is organized in living cells is pivotal to decipher the regulation of biological processes. Here, we demonstrate the improvement of a live imaging technique based on CRISPR/Cas9. In this approach, the sgRNA scaffold is fused to RNA aptamers including MS2 and PP7. When the dead Cas9 (dCas9) is co-expressed with chimeric sgRNA, the fluorescent coat protein-tagged for MS2 and PP7 aptamers (tdMCP-FP and tdPCP-FP) are recruited to the targeted sequence. Compared to previous work with dCas9:GFP, we show that the quality of telomere labeling was improved in transiently transformed Nicotiana benthamiana using aptamer-based CRISPR-imaging constructs. Labeling is influenced by the copy number of aptamers and less by the promoter types. The same constructs were not applicable for labeling of repeats in stably transformed plants and roots. The constant interaction of the RNP complex with its target DNA might interfere with cellular processes.
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Affiliation(s)
- Solmaz Khosravi
- Department for Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Patrick Schindele
- Botanical Institute, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Evgeny Gladilin
- Department for Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Frank Dunemann
- Institute for Breeding Research on Horticultural Crops, Julius Kühn-Institut (JKI), Quedlinburg, Germany
| | - Twan Rutten
- Department for Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Holger Puchta
- Botanical Institute, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Andreas Houben
- Department for Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
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17
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Santos AP, Gaudin V, Mozgová I, Pontvianne F, Schubert D, Tek AL, Dvořáčková M, Liu C, Fransz P, Rosa S, Farrona S. Tidying-up the plant nuclear space: domains, functions, and dynamics. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5160-5178. [PMID: 32556244 PMCID: PMC8604271 DOI: 10.1093/jxb/eraa282] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 06/12/2020] [Indexed: 05/07/2023]
Abstract
Understanding how the packaging of chromatin in the nucleus is regulated and organized to guide complex cellular and developmental programmes, as well as responses to environmental cues is a major question in biology. Technological advances have allowed remarkable progress within this field over the last years. However, we still know very little about how the 3D genome organization within the cell nucleus contributes to the regulation of gene expression. The nuclear space is compartmentalized in several domains such as the nucleolus, chromocentres, telomeres, protein bodies, and the nuclear periphery without the presence of a membrane around these domains. The role of these domains and their possible impact on nuclear activities is currently under intense investigation. In this review, we discuss new data from research in plants that clarify functional links between the organization of different nuclear domains and plant genome function with an emphasis on the potential of this organization for gene regulation.
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Affiliation(s)
- Ana Paula Santos
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova
de Lisboa, Oeiras, Portugal
| | - Valérie Gaudin
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université
Paris-Saclay, Versailles, France
| | - Iva Mozgová
- Biology Centre of the Czech Academy of Sciences, České
Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České
Budějovice, Czech Republic
| | - Frédéric Pontvianne
- CNRS, Laboratoire Génome et Développement des Plantes (LGDP), Université de
Perpignan Via Domitia, Perpignan, France
| | - Daniel Schubert
- Institute for Biology, Freie Universität Berlin, Berlin, Germany
| | - Ahmet L Tek
- Agricultural Genetic Engineering Department, Niğde Ömer Halisdemir
University, Niğde, Turkey
| | | | - Chang Liu
- Center for Plant Molecular Biology (ZMBP), University of
Tübingen, Tübingen, Germany
- Institute of Biology, University of Hohenheim, Stuttgart,
Germany
| | - Paul Fransz
- University of Amsterdam, Amsterdam, The
Netherlands
| | - Stefanie Rosa
- Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Sara Farrona
- Plant and AgriBiosciences Centre, Ryan Institute, NUI Galway,
Galway, Ireland
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18
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Optimized Detection of Protein-Protein and Protein-DNA Interactions, with Particular Application to Plant Telomeres. Methods Mol Biol 2020. [PMID: 32681489 DOI: 10.1007/978-1-0716-0763-3_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Characterization of protein-protein and protein-DNA interactions is critical to understand mechanisms governing the biology of cells. Here we describe optimized methods and their mutual combinations for this purpose: bimolecular fluorescence complementation (BiFC), co-immunoprecipitation (Co-IP), yeast two-hybrid systems (Y2H), and chromatin immunoprecipitation (ChIP). These improved protocols detect trimeric complexes in which two proteins of interest interact indirectly via a protein sandwiched between them. They also allow isolation of low-abundance chromatin proteins and confirmation that proteins of interest are associated with specific DNA sequences, for example telomeric tracts. Here we describe these methods and their application to map interactions of several telomere- and telomerase-associated proteins and to purify a sufficient amount of chromatin from Arabidopsis thaliana for further investigations (e.g., next-generation sequencing, hybridization).
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19
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Kobayashi CR, Castillo-González C, Survotseva Y, Canal E, Nelson ADL, Shippen DE. Recent emergence and extinction of the protection of telomeres 1c gene in Arabidopsis thaliana. PLANT CELL REPORTS 2019; 38:1081-1097. [PMID: 31134349 PMCID: PMC6708462 DOI: 10.1007/s00299-019-02427-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/27/2019] [Indexed: 05/20/2023]
Abstract
Duplicate POT1 genes must rapidly diverge or be inactivated. Protection of telomeres 1 (POT1) encodes a conserved telomere binding protein implicated in both chromosome end protection and telomere length maintenance. Most organisms harbor a single POT1 gene, but in the few lineages where the POT1 family has expanded, the duplicate genes have diversified. Arabidopsis thaliana bears three POT1-like loci, POT1a, POT1b and POT1c. POT1a retains the ancestral function of telomerase regulation, while POT1b is implicated in chromosome end protection. Here we examine the function and evolution of the third POT1 paralog, POT1c. POT1c is a new gene, unique to A. thaliana, and was derived from a duplication event involving the POT1a locus and a neighboring gene encoding ribosomal protein S17. The duplicate S17 locus (dS17) is highly conserved across A. thaliana accessions, while POT1c is highly divergent, harboring multiple deletions within the gene body and two transposable elements within the promoter. The POT1c locus is transcribed at very low to non-detectable levels under standard growth conditions. In addition, no discernable molecular or developmental defects are associated with plants bearing a CRISPR mutation in the POT1c locus. However, forced expression of POT1c leads to decreased telomerase enzyme activity and shortened telomeres. Evolutionary reconstruction indicates that transposons invaded the POT1c promoter soon after the locus was formed, permanently silencing the gene. Altogether, these findings argue that POT1 dosage is critically important for viability and duplicate gene copies are retained only upon functional divergence.
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Affiliation(s)
- Callie R Kobayashi
- Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | | | - Yulia Survotseva
- Yale Center for Molecular Discovery, Yale University, New Haven, Connecticut, USA
| | - Elijah Canal
- Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - Andrew D L Nelson
- The School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Dorothy E Shippen
- Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
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20
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Ishii T, Schubert V, Khosravi S, Dreissig S, Metje‐Sprink J, Sprink T, Fuchs J, Meister A, Houben A. RNA-guided endonuclease - in situ labelling (RGEN-ISL): a fast CRISPR/Cas9-based method to label genomic sequences in various species. THE NEW PHYTOLOGIST 2019; 222:1652-1661. [PMID: 30847946 PMCID: PMC6593734 DOI: 10.1111/nph.15720] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 01/24/2019] [Indexed: 06/02/2023]
Abstract
Visualising the spatio-temporal organisation of the genome will improve our understanding of how chromatin structure and function are intertwined. We developed a tool to visualise defined genomic sequences in fixed nuclei and chromosomes based on a two-part guide RNA with a recombinant Cas9 endonuclease complex. This method does not require any special construct or transformation method. In contrast to classical fluorescence in situ hybridiaztion, RGEN-ISL (RNA-guided endonuclease - in situ labelling) does not require DNA denaturation, and therefore permits a better structural chromatin preservation. The application of differentially labelled trans-activating crRNAs allows the multiplexing of RGEN-ISL. Moreover, this technique is combinable with immunohistochemistry. Real-time visualisation of the CRISPR/Cas9-mediated DNA labelling process revealed the kinetics of the reaction. The broad range of adaptability of RGEN-ISL to different temperatures and combinations of methods has the potential to advance the field of chromosome biology.
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Affiliation(s)
- Takayoshi Ishii
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) GaterslebenSeelandD‐06466Germany
- Arid Land Research Center (ALRC)Tottori University1390 HamasakaTottori680‐0001Japan
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) GaterslebenSeelandD‐06466Germany
| | - Solmaz Khosravi
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) GaterslebenSeelandD‐06466Germany
| | - Steven Dreissig
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) GaterslebenSeelandD‐06466Germany
| | - Janina Metje‐Sprink
- Julius Kühn‐InstituteInstitute of Biosafety in Plant BiotechnologyQuedlinburgD‐06484Germany
| | - Thorben Sprink
- Julius Kühn‐InstituteInstitute of Biosafety in Plant BiotechnologyQuedlinburgD‐06484Germany
| | - Jörg Fuchs
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) GaterslebenSeelandD‐06466Germany
| | - Armin Meister
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) GaterslebenSeelandD‐06466Germany
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) GaterslebenSeelandD‐06466Germany
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21
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Schořová Š, Fajkus J, Záveská Drábková L, Honys D, Schrumpfová PP. The plant Pontin and Reptin homologues, RuvBL1 and RuvBL2a, colocalize with TERT and TRB proteins in vivo, and participate in telomerase biogenesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:195-212. [PMID: 30834599 DOI: 10.1111/tpj.14306] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 02/08/2019] [Accepted: 02/26/2019] [Indexed: 05/15/2023]
Abstract
Telomerase maturation and recruitment to telomeres is regulated by several telomerase- and telomere-associated proteins. Among a number of proteins, human Pontin and Reptin play critical roles in telomerase biogenesis. Here we characterized plant orthologues of Pontin and Reptin, RuvBL1 and RuvBL2a, respectively, and show association of Arabidopsis thaliana RuvBL1 (AtRuvBL1) with the catalytic subunit of telomerase (AtTERT) in the nucleolus in vivo. In contrast to mammals, interactions between AtTERT and AtRuvBL proteins in A. thaliana are not direct and they are rather mediated by one of the Arabidopsis thaliana Telomere Repeat Binding (AtTRB) proteins. We further show that plant orthologue of dyskerin, named AtCBF5, is indirectly associated with AtTRB proteins but not with the AtRuvBL proteins in the plant nucleus/nucleolus, and interacts with the Protection of telomere 1 (AtPOT1a) in the nucleolus or cytoplasmic foci. Our genome-wide phylogenetic analyses identify orthologues in RuvBL protein family within the plant kingdom. Dysfunction of AtRuvBL genes in heterozygous T-DNA insertion A. thaliana mutants results in reduced telomerase activity and indicate the involvement of AtRuvBL in plant telomerase biogenesis.
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Affiliation(s)
- Šárka Schořová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- Institute of Biophysics of the Czech Academy of Sciences, v.v.i., Brno, Czech Republic
| | - Lenka Záveská Drábková
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic
| | - Petra Procházková Schrumpfová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
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22
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Abstract
Epigenetic gene regulation ensures the mitotically or meiotically stable heritability (or both) of gene expression or protein activity states and maintains repetitive element repression and cellular identities. The repressive Polycomb-group (PcG) proteins consist of several large complexes that control cellular memory by acting on chromatin and are antagonized by the Trithorax-group proteins. Especially, Polycomb repressive complex 2 (PRC2) is highly conserved in plants and animals but its function in unicellular eukaryotes and during land plant evolution is less understood. Additional PcG complexes and associated proteins are only partially conserved and have evolved in a lineage-specific manner. In this review, I will focus on recent advances in the understanding of PcG function in the green lineage and its contribution to land plant evolution.
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Affiliation(s)
- Daniel Schubert
- Department of Biology, Epigenetics of Plants, Freie Universität Berlin, Berlin, Germany
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23
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Telomeres in Plants and Humans: Not So Different, Not So Similar. Cells 2019; 8:cells8010058. [PMID: 30654521 PMCID: PMC6356271 DOI: 10.3390/cells8010058] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/07/2019] [Accepted: 01/07/2019] [Indexed: 01/01/2023] Open
Abstract
Parallel research on multiple model organisms shows that while some principles of telomere biology are conserved among all eukaryotic kingdoms, we also find some deviations that reflect different evolutionary paths and life strategies, which may have diversified after the establishment of telomerase as a primary mechanism for telomere maintenance. Much more than animals, plants have to cope with environmental stressors, including genotoxic factors, due to their sessile lifestyle. This is, in principle, made possible by an increased capacity and efficiency of the molecular systems ensuring maintenance of genome stability, as well as a higher tolerance to genome instability. Furthermore, plant ontogenesis differs from that of animals in which tissue differentiation and telomerase silencing occur during early embryonic development, and the “telomere clock” in somatic cells may act as a preventive measure against carcinogenesis. This does not happen in plants, where growth and ontogenesis occur through the serial division of apical meristems consisting of a small group of stem cells that generate a linear series of cells, which differentiate into an array of cell types that make a shoot and root. Flowers, as generative plant organs, initiate from the shoot apical meristem in mature plants which is incompatible with the human-like developmental telomere shortening. In this review, we discuss differences between human and plant telomere biology and the implications for aging, genome stability, and cell and organism survival. In particular, we provide a comprehensive comparative overview of telomere proteins acting in humans and in Arabidopsis thaliana model plant, and discuss distinct epigenetic features of telomeric chromatin in these species.
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24
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Byun MY, Cui LH, Lee H, Kim WT. Telomere association of Oryza sativa telomere repeat-binding factor like 1 and its roles in telomere maintenance and development in rice, Oryza sativa L. BMB Rep 2018. [PMID: 29936933 PMCID: PMC6283022 DOI: 10.5483/bmbrep.2018.51.11.122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Telomeres are specialized nucleoprotein complexes that function to protect eukaryotic chromosomes from recombination and erosion. Several telomere binding proteins (TBPs) have been characterized in higher plants, but their detailed in vivo functions at the plant level are largely unknown. In this study, we identified and characterized OsTRFL1 (Oryza sativa Telomere Repeat-binding Factor Like 1) in rice, a monocot model crop. Although OsTRFL1 did not directly bind to telomere repeats (TTTAGGG)4in vitro, it was associated with telomeric sequences in planta. OsTRFL1 interacted with rice TBPs, such as OsTRBF1 and RTBP1, in yeast and plant cells as well as in vitro. Thus, it seems likely that the association of OsTRFL1 with other TBPs enables OsTRFL1 to bind to telomeres indirectly. T-DNA inserted OsTRFL1 knock-out mutant rice plants displayed significantly longer telomeres (6–25 kb) than those (5–12 kb) in wild-type plants, indicating that OsTRFL1 is a negative factor for telomere lengthening. The reduced levels of OsTRFL1 caused serious developmental defects in both vegetative and reproductive organs of rice plants. These results suggest that OsTRFL1 is an essential factor for the proper maintenance of telomeres and normal development of rice.
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Affiliation(s)
- Mi Young Byun
- Unit of Polar Genomics, Korea Polar Research Institute, Incheon 21990, Korea
| | - Li Hua Cui
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
| | - Hyoungseok Lee
- Unit of Polar Genomics, Korea Polar Research Institute, Incheon 21990, Korea
| | - Woo Taek Kim
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
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25
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Rendón-Gandarilla FJ, Álvarez-Hernández V, Castañeda-Ortiz EJ, Cárdenas-Hernández H, Cárdenas-Guerra RE, Valdés J, Betanzos A, Chávez-Munguía B, Lagunes-Guillen A, Orozco E, López-Canovas L, Azuara-Liceaga E. Telomeric Repeat-Binding Factor Homologs in Entamoeba histolytica: New Clues for Telomeric Research. Front Cell Infect Microbiol 2018; 8:341. [PMID: 30333961 PMCID: PMC6175992 DOI: 10.3389/fcimb.2018.00341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/10/2018] [Indexed: 12/19/2022] Open
Abstract
Telomeric Repeat Binding Factors (TRFs) are architectural nuclear proteins with critical roles in telomere-length regulation, chromosome end protection and, fusion prevention, DNA damage detection, and senescence regulation. Entamoeba histolytica, the parasite responsible of human amoebiasis, harbors three homologs of human TRFs, based on sequence similarities to their Myb DNA binding domain. These proteins were dubbed EhTRF-like I, II and III. In this work, we revealed that EhTRF-like I and II share similarity with human TRF1, while EhTRF-like III shares similarity with human TRF2 by in silico approach. The analysis of ehtrf-like genes showed they are expressed differentially under basal culture conditions. We also studied the cellular localization of EhTRF-like I and III proteins using subcellular fractionation and western blot assays. EhTRF-like I and III proteins were enriched in the nuclear fraction, but they were also present in the cytoplasm. Indirect immunofluorescence showed that these proteins were located at the nuclear periphery co-localizing with Lamin B1 and trimethylated H4K20, which is a characteristic mark of heterochromatic regions and telomeres. We found by transmission electron microscopy that EhTRF-like III was located in regions of more condensed chromatin. Finally, EMSA assays showed that EhTRF-like III forms specific DNA-protein complexes with telomeric related sequences. Our data suggested that EhTRF-like proteins play a role in the maintenance of the chromosome ends in this parasite.
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Affiliation(s)
| | - Víctor Álvarez-Hernández
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de Mexico, Mexico City, Mexico
| | | | | | | | - Jesús Valdés
- Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Abigail Betanzos
- Consejo Nacional de Ciencia y Tecnología, Mexico City, Mexico.,Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Bibiana Chávez-Munguía
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Anel Lagunes-Guillen
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Esther Orozco
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Lilia López-Canovas
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de Mexico, Mexico City, Mexico
| | - Elisa Azuara-Liceaga
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de Mexico, Mexico City, Mexico
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26
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Sováková PP, Magdolenová A, Konečná K, Rájecká V, Fajkus J, Fojtová M. Telomere elongation upon transfer to callus culture reflects the reprogramming of telomere stability control in Arabidopsis. PLANT MOLECULAR BIOLOGY 2018; 98:81-99. [PMID: 30128721 DOI: 10.1007/s11103-018-0765-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 08/12/2018] [Indexed: 05/23/2023]
Abstract
KEY MESSAGE Standard pathways involved in the regulation of telomere stability do not contribute to gradual telomere elongation observed in the course of A. thaliana calli propagation. Genetic and epigenetic changes accompanying the culturing of plant cells have frequently been reported. Here we aimed to characterize the telomere homeostasis during long term callus propagation. While in Arabidopsis thaliana calli gradual telomere elongation was observed, telomeres were stable in Nicotiana tabacum and N. sylvestris cultures. Telomere elongation during callus propagation is thus not a general feature of plant cells. The long telomere phenotype in Arabidopsis calli was correlated neither with changes in telomerase activity nor with activation of alternative mechanisms of telomere elongation. The dynamics of telomere length changes was maintained in mutant calli with loss of function of important epigenetic modifiers but compromised in the presence of epigenetically active drug zebularine. To examine whether the cell culture-induced disruption of telomere homeostasis is associated with the modulated structure of chromosome ends, epigenetic properties of telomere chromatin were analysed. Albeit distinct changes in epigenetic modifications of telomere histones were observed, these were broadly stochastic. Our results show that contrary to animal cells, the structure and function of plant telomeres is not determined significantly by the epigenetic character of telomere chromatin. Set of differentially transcribed genes was identified in calli, but considering the known telomere- or telomerase-related functions of respective proteins, none of these changes per se was apparently related to the elongated telomere phenotype. Based on our data, we propose that the disruption in telomere homeostasis in Arabidopsis calli arises from the interplay of multiple factors, as a part of reprogramming of plant cells to long-term culture conditions.
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Affiliation(s)
- Pavla Polanská Sováková
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
| | - Alžbeta Magdolenová
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic v.v.i., Prague, Czech Republic
| | - Klára Konečná
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
| | - Veronika Rájecká
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., 612 65, Brno, Czech Republic
| | - Miloslava Fojtová
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic.
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic.
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27
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Tan LM, Zhang CJ, Hou XM, Shao CR, Lu YJ, Zhou JX, Li YQ, Li L, Chen S, He XJ. The PEAT protein complexes are required for histone deacetylation and heterochromatin silencing. EMBO J 2018; 37:embj.201798770. [PMID: 30104406 DOI: 10.15252/embj.201798770] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 01/26/2023] Open
Abstract
In eukaryotes, heterochromatin regions are typically subjected to transcriptional silencing. DNA methylation has an important role in such silencing and has been studied extensively. However, little is known about how methylated heterochromatin regions are subjected to silencing. We conducted a genetic screen and identified an epcr (enhancer of polycomb-related) mutant that releases heterochromatin silencing in Arabidopsis thaliana We demonstrated that EPCR1 functions redundantly with its paralog EPCR2 and interacts with PWWP domain-containing proteins (PWWPs), AT-rich interaction domain-containing proteins (ARIDs), and telomere repeat binding proteins (TRBs), thus forming multiple functionally redundant protein complexes named PEAT (PWWPs-EPCRs-ARIDs-TRBs). The PEAT complexes mediate histone deacetylation and heterochromatin condensation and thereby facilitate heterochromatin silencing. In heterochromatin regions, the production of small interfering RNAs (siRNAs) and DNA methylation is repressed by the PEAT complexes. The study reveals how histone deacetylation, heterochromatin condensation, siRNA production, and DNA methylation interplay with each other and thereby maintain heterochromatin silencing.
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Affiliation(s)
- Lian-Mei Tan
- National Institute of Biological Sciences, Beijing, China.,Graduate School of Peking Union Medical College, Beijing, China
| | - Cui-Jun Zhang
- National Institute of Biological Sciences, Beijing, China
| | - Xiao-Mei Hou
- National Institute of Biological Sciences, Beijing, China
| | | | - Yu-Jia Lu
- National Institute of Biological Sciences, Beijing, China
| | - Jin-Xing Zhou
- National Institute of Biological Sciences, Beijing, China
| | - Yong-Qiang Li
- National Institute of Biological Sciences, Beijing, China
| | - Lin Li
- National Institute of Biological Sciences, Beijing, China
| | - She Chen
- National Institute of Biological Sciences, Beijing, China
| | - Xin-Jian He
- National Institute of Biological Sciences, Beijing, China .,Graduate School of Peking Union Medical College, Beijing, China
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28
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Dokládal L, Benková E, Honys D, Dupľáková N, Lee LY, Gelvin SB, Sýkorová E. An armadillo-domain protein participates in a telomerase interaction network. PLANT MOLECULAR BIOLOGY 2018; 97:407-420. [PMID: 29948659 DOI: 10.1007/s11103-018-0747-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
Arabidopsis and human ARM protein interact with telomerase. Deregulated mRNA levels of DNA repair and ribosomal protein genes in an Arabidopsis arm mutant suggest non-telomeric ARM function. The human homolog ARMC6 interacts with hTRF2. Telomerase maintains telomeres and has proposed non-telomeric functions. We previously identified interaction of the C-terminal domain of Arabidopsis telomerase reverse transcriptase (AtTERT) with an armadillo/β-catenin-like repeat (ARM) containing protein. Here we explore protein-protein interactions of the ARM protein, AtTERT domains, POT1a, TRF-like family and SMH family proteins, and the chromatin remodeling protein CHR19 using bimolecular fluorescence complementation (BiFC), yeast two-hybrid (Y2H) analysis, and co-immunoprecipitation. The ARM protein interacts with both the N- and C-terminal domains of AtTERT in different cellular compartments. ARM interacts with CHR19 and TRF-like I family proteins that also bind AtTERT directly or through interaction with POT1a. The putative human ARM homolog co-precipitates telomerase activity and interacts with hTRF2 protein in vitro. Analysis of Arabidopsis arm mutants shows no obvious changes in telomere length or telomerase activity, suggesting that ARM is not essential for telomere maintenance. The observed interactions with telomerase and Myb-like domain proteins (TRF-like family I) may therefore reflect possible non-telomeric functions. Transcript levels of several DNA repair and ribosomal genes are affected in arm mutants, and ARM, likely in association with other proteins, suppressed expression of XRCC3 and RPSAA promoter constructs in luciferase reporter assays. In conclusion, ARM can participate in non-telomeric functions of telomerase, and can also perform its own telomerase-independent functions.
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Affiliation(s)
- Ladislav Dokládal
- Institute of Biophysics, The Czech Academy of Sciences, Královopolská 135, 61265, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
- Department of Biology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Eva Benková
- Institute of Science and Technology Austria, 3400, Klosterneuburg, Austria
| | - David Honys
- Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojova 263, 16502, Prague, Czech Republic
| | - Nikoleta Dupľáková
- Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojova 263, 16502, Prague, Czech Republic
| | - Lan-Ying Lee
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907-1392, USA
| | - Stanton B Gelvin
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907-1392, USA
| | - Eva Sýkorová
- Institute of Biophysics, The Czech Academy of Sciences, Královopolská 135, 61265, Brno, Czech Republic.
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29
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Charbonnel C, Rymarenko O, Da Ines O, Benyahya F, White CI, Butter F, Amiard S. The Linker Histone GH1-HMGA1 Is Involved in Telomere Stability and DNA Damage Repair. PLANT PHYSIOLOGY 2018; 177:311-327. [PMID: 29622687 PMCID: PMC5933147 DOI: 10.1104/pp.17.01789] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 03/28/2018] [Indexed: 05/19/2023]
Abstract
Despite intensive searches, few proteins involved in telomere homeostasis have been identified in plants. Here, we used pull-down assays to identify potential telomeric interactors in the model plant species Arabidopsis (Arabidopsis thaliana). We identified the candidate protein GH1-HMGA1 (also known as HON4), an uncharacterized linker histone protein of the High Mobility Group Protein A (HMGA) family in plants. HMGAs are architectural transcription factors and have been suggested to function in DNA damage repair, but their precise biological roles remain unclear. Here, we show that GH1-HMGA1 is required for efficient DNA damage repair and telomere integrity in Arabidopsis. GH1-HMGA1 mutants exhibit developmental and growth defects, accompanied by ploidy defects, increased telomere dysfunction-induced foci, mitotic anaphase bridges, and degraded telomeres. Furthermore, mutants have a higher sensitivity to genotoxic agents such as mitomycin C and γ-irradiation. Our work also suggests that GH1-HMGA1 is involved directly in the repair process by allowing the completion of homologous recombination.
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Affiliation(s)
- Cyril Charbonnel
- Génétique, Reproduction, et Dévélopement, Université Clermont Auvergne-Centre National de la Recherche Scientifique Unité Mixte de Recherche 6293-INSERM U1103, F-63000 Clermont-Ferrand, France
| | | | - Olivier Da Ines
- Génétique, Reproduction, et Dévélopement, Université Clermont Auvergne-Centre National de la Recherche Scientifique Unité Mixte de Recherche 6293-INSERM U1103, F-63000 Clermont-Ferrand, France
| | - Fatiha Benyahya
- Génétique, Reproduction, et Dévélopement, Université Clermont Auvergne-Centre National de la Recherche Scientifique Unité Mixte de Recherche 6293-INSERM U1103, F-63000 Clermont-Ferrand, France
| | - Charles I White
- Génétique, Reproduction, et Dévélopement, Université Clermont Auvergne-Centre National de la Recherche Scientifique Unité Mixte de Recherche 6293-INSERM U1103, F-63000 Clermont-Ferrand, France
| | - Falk Butter
- Institute of Molecular Biology, 455128 Mainz, Germany
| | - Simon Amiard
- Génétique, Reproduction, et Dévélopement, Université Clermont Auvergne-Centre National de la Recherche Scientifique Unité Mixte de Recherche 6293-INSERM U1103, F-63000 Clermont-Ferrand, France
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30
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Telobox motifs recruit CLF/SWN–PRC2 for H3K27me3 deposition via TRB factors in Arabidopsis. Nat Genet 2018; 50:638-644. [DOI: 10.1038/s41588-018-0109-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 03/13/2018] [Indexed: 12/25/2022]
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31
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Shi Y, Yue X, An L. Integrated regulation triggered by a cryophyte ω-3 desaturase gene confers multiple-stress tolerance in tobacco. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:2131-2148. [PMID: 29432580 PMCID: PMC6019038 DOI: 10.1093/jxb/ery050] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/02/2018] [Indexed: 05/16/2023]
Abstract
ω-3 fatty acid desaturases (FADs) are thought to contribute to plant stress tolerance mainly through linolenic acid (C18:3)-induced membrane stabilization, but a comprehensive analysis of their roles in stress adaptation is lacking. Here, we isolated a microsomal ω-3 FAD gene (CbFAD3) from a cryophyte (Chorispora bungeana) and elucidated its functions in stress tolerance. CbFAD3, exhibiting a high identity to Arabidopsis AtFAD3, was up-regulated by abiotic stresses. Its functionality was verified by heterogonous expression in yeast. Overexpression of CbFAD3 in tobacco constitutively increased C18:3 in both leaves and roots, which maintained the membrane fluidity, and enhanced plant tolerance to cold, drought, and salt stresses. Notably, the constitutively increased C18:3 induced a sustained activation of plasma membrane Ca2+-ATPase, thereby, changing the stress-induced Ca2+ signaling. The reactive oxygen species (ROS) scavenging system, which was positively correlated with the level of C18:3, was also activated in the transgenic lines. Microarray analysis showed that CbFAD3-overexpressing plants increased the expression of stress-responsive genes, most of which are affected by C18:3, Ca2+, or ROS. Together, CbFAD3 confers tolerance to multiple stresses in tobacco through the C18:3-induced integrated regulation of membrane, Ca2+, ROS, and stress-responsive genes. This is in contrast with previous observations that simply attribute stress tolerance to membrane stabilization.
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Affiliation(s)
- Yulan Shi
- Extreme Stress Resistance and Biotechnology Laboratory, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, PR China
| | - Xiule Yue
- School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Lizhe An
- Extreme Stress Resistance and Biotechnology Laboratory, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, PR China
- School of Life Sciences, Lanzhou University, Lanzhou, PR China
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32
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Dreissig S, Schiml S, Schindele P, Weiss O, Rutten T, Schubert V, Gladilin E, Mette MF, Puchta H, Houben A. Live-cell CRISPR imaging in plants reveals dynamic telomere movements. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 91:565-573. [PMID: 28509419 PMCID: PMC5599988 DOI: 10.1111/tpj.13601] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/11/2017] [Accepted: 05/09/2017] [Indexed: 05/11/2023]
Abstract
Elucidating the spatiotemporal organization of the genome inside the nucleus is imperative to our understanding of the regulation of genes and non-coding sequences during development and environmental changes. Emerging techniques of chromatin imaging promise to bridge the long-standing gap between sequencing studies, which reveal genomic information, and imaging studies that provide spatial and temporal information of defined genomic regions. Here, we demonstrate such an imaging technique based on two orthologues of the bacterial clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated protein 9 (Cas9). By fusing eGFP/mRuby2 to catalytically inactive versions of Streptococcus pyogenes and Staphylococcus aureus Cas9, we show robust visualization of telomere repeats in live leaf cells of Nicotiana benthamiana. By tracking the dynamics of telomeres visualized by CRISPR-dCas9, we reveal dynamic telomere movements of up to 2 μm over 30 min during interphase. Furthermore, we show that CRISPR-dCas9 can be combined with fluorescence-labelled proteins to visualize DNA-protein interactions in vivo. By simultaneously using two dCas9 orthologues, we pave the way for the imaging of multiple genomic loci in live plants cells. CRISPR imaging bears the potential to significantly improve our understanding of the dynamics of chromosomes in live plant cells.
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Affiliation(s)
- Steven Dreissig
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)Gatersleben06466SeelandGermany
| | - Simon Schiml
- Botanical InstituteKarlsruhe Institute of TechnologyPOB 698076049KarlsruheGermany
| | - Patrick Schindele
- Botanical InstituteKarlsruhe Institute of TechnologyPOB 698076049KarlsruheGermany
| | - Oda Weiss
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)Gatersleben06466SeelandGermany
| | - Twan Rutten
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)Gatersleben06466SeelandGermany
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)Gatersleben06466SeelandGermany
| | - Evgeny Gladilin
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)Gatersleben06466SeelandGermany
| | - Michael F. Mette
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)Gatersleben06466SeelandGermany
- Present address:
King Abdullah University of Science & TechnologyThuwal23955‐6900Saudi Arabia
| | - Holger Puchta
- Botanical InstituteKarlsruhe Institute of TechnologyPOB 698076049KarlsruheGermany
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)Gatersleben06466SeelandGermany
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Majerská J, Schrumpfová PP, Dokládal L, Schořová Š, Stejskal K, Obořil M, Honys D, Kozáková L, Polanská PS, Sýkorová E. Tandem affinity purification of AtTERT reveals putative interaction partners of plant telomerase in vivo. PROTOPLASMA 2017; 254:1547-1562. [PMID: 27853871 DOI: 10.1007/s00709-016-1042-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/04/2016] [Indexed: 05/15/2023]
Abstract
The life cycle of telomerase involves dynamic and complex interactions between proteins within multiple macromolecular networks. Elucidation of these associations is a key to understanding the regulation of telomerase under diverse physiological and pathological conditions from telomerase biogenesis, through telomere recruitment and elongation, to its non-canonical activities outside of telomeres. We used tandem affinity purification coupled to mass spectrometry to build an interactome of the telomerase catalytic subunit AtTERT, using Arabidopsis thaliana suspension cultures. We then examined interactions occurring at the AtTERT N-terminus, which is thought to fold into a discrete domain connected to the rest of the molecule via a flexible linker. Bioinformatic analyses revealed that interaction partners of AtTERT have a range of molecular functions, a subset of which is specific to the network around its N-terminus. A significant number of proteins co-purifying with the N-terminal constructs have been implicated in cell cycle and developmental processes, as would be expected of bona fide regulatory interactions and we have confirmed experimentally the direct nature of selected interactions. To examine AtTERT protein-protein interactions from another perspective, we also analysed AtTERT interdomain contacts to test potential dimerization of AtTERT. In total, our results provide an insight into the composition and architecture of the plant telomerase complex and this will aid in delineating molecular mechanisms of telomerase functions.
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Affiliation(s)
- Jana Majerská
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic
- Central European Institute of Technology and Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Petra Procházková Schrumpfová
- Central European Institute of Technology and Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Ladislav Dokládal
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic
| | - Šárka Schořová
- Central European Institute of Technology and Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
| | - Karel Stejskal
- Central European Institute of Technology and Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
| | - Michal Obořil
- Central European Institute of Technology and Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
| | - David Honys
- Institute of Experimental Biology, Academy of Sciences of the Czech Republic, v.v.i., Rozvojová 263, CZ-165 02, Prague, Czech Republic
| | - Lucie Kozáková
- Central European Institute of Technology and Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
| | - Pavla Sováková Polanská
- Central European Institute of Technology and Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
| | - Eva Sýkorová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic.
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Kotliński M, Knizewski L, Muszewska A, Rutowicz K, Lirski M, Schmidt A, Baroux C, Ginalski K, Jerzmanowski A. Phylogeny-Based Systematization of Arabidopsis Proteins with Histone H1 Globular Domain. PLANT PHYSIOLOGY 2017; 174:27-34. [PMID: 28298478 PMCID: PMC5411143 DOI: 10.1104/pp.16.00214] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/10/2017] [Indexed: 05/19/2023]
Abstract
H1 (or linker) histones are basic nuclear proteins that possess an evolutionarily conserved nucleosome-binding globular domain, GH1. They perform critical functions in determining the accessibility of chromatin DNA to trans-acting factors. In most metazoan species studied so far, linker histones are highly heterogenous, with numerous nonallelic variants cooccurring in the same cells. The phylogenetic relationships among these variants as well as their structural and functional properties have been relatively well established. This contrasts markedly with the rather limited knowledge concerning the phylogeny and structural and functional roles of an unusually diverse group of GH1-containing proteins in plants. The dearth of information and the lack of a coherent phylogeny-based nomenclature of these proteins can lead to misunderstandings regarding their identity and possible relationships, thereby hampering plant chromatin research. Based on published data and our in silico and high-throughput analyses, we propose a systematization and coherent nomenclature of GH1-containing proteins of Arabidopsis (Arabidopsis thaliana [L.] Heynh) that will be useful for both the identification and structural and functional characterization of homologous proteins from other plant species.
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Affiliation(s)
- Maciej Kotliński
- Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland (M.K., A.J.)
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland (L.K., K.G.)
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland (A.M., K.R., M.L., A.J.)
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, 8008 Zurich, Switzerland (K.R., C.B.); and
- Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany (A.S.)
| | - Lukasz Knizewski
- Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland (M.K., A.J.)
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland (L.K., K.G.)
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland (A.M., K.R., M.L., A.J.)
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, 8008 Zurich, Switzerland (K.R., C.B.); and
- Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany (A.S.)
| | - Anna Muszewska
- Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland (M.K., A.J.)
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland (L.K., K.G.)
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland (A.M., K.R., M.L., A.J.)
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, 8008 Zurich, Switzerland (K.R., C.B.); and
- Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany (A.S.)
| | - Kinga Rutowicz
- Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland (M.K., A.J.)
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland (L.K., K.G.)
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland (A.M., K.R., M.L., A.J.)
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, 8008 Zurich, Switzerland (K.R., C.B.); and
- Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany (A.S.)
| | - Maciej Lirski
- Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland (M.K., A.J.)
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland (L.K., K.G.)
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland (A.M., K.R., M.L., A.J.)
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, 8008 Zurich, Switzerland (K.R., C.B.); and
- Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany (A.S.)
| | - Anja Schmidt
- Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland (M.K., A.J.)
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland (L.K., K.G.)
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland (A.M., K.R., M.L., A.J.)
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, 8008 Zurich, Switzerland (K.R., C.B.); and
- Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany (A.S.)
| | - Célia Baroux
- Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland (M.K., A.J.);
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland (L.K., K.G.);
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland (A.M., K.R., M.L., A.J.);
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, 8008 Zurich, Switzerland (K.R., C.B.); and
- Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany (A.S.)
| | - Krzysztof Ginalski
- Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland (M.K., A.J.)
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland (L.K., K.G.)
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland (A.M., K.R., M.L., A.J.)
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, 8008 Zurich, Switzerland (K.R., C.B.); and
- Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany (A.S.)
| | - Andrzej Jerzmanowski
- Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland (M.K., A.J.);
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland (L.K., K.G.);
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland (A.M., K.R., M.L., A.J.);
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, 8008 Zurich, Switzerland (K.R., C.B.); and
- Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany (A.S.)
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Hayama R, Sarid-Krebs L, Richter R, Fernández V, Jang S, Coupland G. PSEUDO RESPONSE REGULATORs stabilize CONSTANS protein to promote flowering in response to day length. EMBO J 2017; 36:904-918. [PMID: 28270524 PMCID: PMC5376961 DOI: 10.15252/embj.201693907] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 01/31/2017] [Accepted: 02/01/2017] [Indexed: 11/09/2022] Open
Abstract
Seasonal reproduction in many organisms requires detection of day length. This is achieved by integrating information on the light environment with an internal photoperiodic time-keeping mechanism. Arabidopsis thaliana promotes flowering in response to long days (LDs), and CONSTANS (CO) transcription factor represents a photoperiodic timer whose stability is higher when plants are exposed to light under LDs. Here, we show that PSEUDO RESPONSE REGULATOR (PRR) proteins directly mediate this stabilization. PRRs interact with and stabilize CO at specific times during the day, thereby mediating its accumulation under LDs. PRR-mediated stabilization increases binding of CO to the promoter of FLOWERING LOCUS T (FT), leading to enhanced FT transcription and early flowering under these conditions. PRRs were previously reported to contribute to timekeeping by regulating CO transcription through their roles in the circadian clock. We propose an additional role for PRRs in which they act upon CO protein to promote flowering, directly coupling information on light exposure to the timekeeper and allowing recognition of LDs.
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Affiliation(s)
- Ryosuke Hayama
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Liron Sarid-Krebs
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - René Richter
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Virginia Fernández
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Seonghoe Jang
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - George Coupland
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
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36
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Lee WK, Cho MH. Telomere-binding protein regulates the chromosome ends through the interaction with histone deacetylases in Arabidopsis thaliana. Nucleic Acids Res 2016; 44:4610-24. [PMID: 26857545 PMCID: PMC4889915 DOI: 10.1093/nar/gkw067] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 01/20/2016] [Accepted: 01/28/2016] [Indexed: 01/13/2023] Open
Abstract
Telomeres are nucleoprotein complexes at the end of eukaryotic chromosomes. Many telomere-binding proteins bind to telomeric repeat sequences and further generate T-loops in animals. However, it is not clear if they regulate telomere organization using epigenetic mechanisms and how the epigenetic molecules are involved in regulating the telomeres. Here, we show direct interactions between the telomere-binding protein, AtTRB2 and histone deacetylases, HDT4 and HDA6, in vitro and in vivo AtTRB2 mediates the associations of HDT4 and HDA6 with telomeric repeats. Telomere elongation is found in AtTRB2, HDT4 and HDA6 mutants over generations, but also in met1 and cmt3 DNA methyltransferases mutants. We also characterized HDT4 as an Arabidopsis H3K27 histone deacetylase. HDT4 binds to acetylated peptides at residue K27 of histone H3 in vitro, and deacetylates this residue in vivo Our results suggest that AtTRB2 also has a role in the regulation of telomeric chromatin as a possible scaffold protein for recruiting the epigenetic regulators in Arabidopsis, in addition to its telomere binding and length regulation activity. Our data provide evidences that epigenetic molecules associate with telomeres by direct physical interaction with telomere-binding proteins and further regulate homeostasis of telomeres in Arabidopsis thaliana.
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Affiliation(s)
- Won Kyung Lee
- Department of Systems Biology, Yonsei University, Seoul 03722, Republic of Korea
| | - Myeon Haeng Cho
- Department of Systems Biology, Yonsei University, Seoul 03722, Republic of Korea
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Fulcher N, Riha K. Using Centromere Mediated Genome Elimination to Elucidate the Functional Redundancy of Candidate Telomere Binding Proteins in Arabidopsis thaliana. Front Genet 2016; 6:349. [PMID: 26779251 PMCID: PMC4700174 DOI: 10.3389/fgene.2015.00349] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 11/29/2015] [Indexed: 12/23/2022] Open
Abstract
Proteins that bind to telomeric DNA form the key structural and functional constituents of telomeres. While telomere binding proteins have been described in the majority of organisms, their identity in plants remains unknown. Several protein families containing a telomere binding motif known as the telobox have been previously described in Arabidopsis thaliana. Nonetheless, functional evidence for their involvement at telomeres has not been obtained, likely due to functional redundancy. Here we performed genetic analysis on the TRF-like family consisting of six proteins (TRB1, TRP1, TRFL1, TRFL2, TRFL4, and TRF9) which have previously shown to bind telomeric DNA in vitro. We used haploid genetics to create multiple knock-out plants deficient for all six proteins of this gene family. These plants did not exhibit changes in telomere length, or phenotypes associated with telomere dysfunction. This data demonstrates that this telobox protein family is not involved in telomere maintenance in Arabidopsis. Phylogenetic analysis in major plant lineages revealed early diversification of telobox proteins families indicating that telomere function may be associated with other telobox proteins.
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Affiliation(s)
- Nick Fulcher
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Austria
| | - Karel Riha
- Central European Institute of Technology, Masaryk University, Brno Czech Republic
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Zhou Y, Hartwig B, James GV, Schneeberger K, Turck F. Complementary Activities of TELOMERE REPEAT BINDING Proteins and Polycomb Group Complexes in Transcriptional Regulation of Target Genes. THE PLANT CELL 2016; 28:87-101. [PMID: 26721861 PMCID: PMC4746681 DOI: 10.1105/tpc.15.00787] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/11/2015] [Accepted: 12/25/2015] [Indexed: 05/19/2023]
Abstract
In multicellular organisms, Polycomb Repressive Complex 1 (PRC1) and PRC2 repress target genes through histone modification and chromatin compaction. Arabidopsis thaliana mutants strongly compromised in the pathway cannot develop differentiated organs. LIKE HETEROCHROMATIN PROTEIN1 (LHP1) is so far the only known plant PRC1 component that directly binds to H3K27me3, the histone modification set by PRC2, and also associates genome-wide with trimethylation of lysine 27 of histone H3 (H3K27me3). Surprisingly, lhp1 mutants show relatively mild phenotypic alterations. To explain this paradox, we screened for genetic enhancers of lhp1 mutants to identify novel components repressing target genes together with, or in parallel to, LHP1. Two enhancing mutations were mapped to TELOMERE REPEAT BINDING PROTEIN1 (TRB1) and its paralog TRB3. We show that TRB1 binds to thousands of genomic sites containing telobox or related cis-elements with a significant increase of sites and strength of binding in the lhp1 background. Furthermore, in combination with lhp1, but not alone, trb1 mutants show increased transcription of LHP1 targets, such as floral meristem identity genes, which are more likely to be bound by TRB1 in the lhp1 background. By contrast, expression of a subset of LHP1-independent TRB1 target genes, many involved in primary metabolism, is decreased in the absence of TRB1 alone. Thus, TRB1 is a bivalent transcriptional modulator that maintains downregulation of Polycomb Group (PcG) target genes in lhp1 mutants, while it sustains high expression of targets that are regulated independently of PcG.
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Affiliation(s)
- Yue Zhou
- Department Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, 50829 Köln, Germany
| | - Benjamin Hartwig
- Department Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, 50829 Köln, Germany
| | - Geo Velikkakam James
- Department Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, 50829 Köln, Germany
| | - Korbinian Schneeberger
- Department Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, 50829 Köln, Germany
| | - Franziska Turck
- Department Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, 50829 Köln, Germany
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Procházková Schrumpfová P, Schořová Š, Fajkus J. Telomere- and Telomerase-Associated Proteins and Their Functions in the Plant Cell. FRONTIERS IN PLANT SCIENCE 2016; 7:851. [PMID: 27446102 PMCID: PMC4924339 DOI: 10.3389/fpls.2016.00851] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 05/31/2016] [Indexed: 05/20/2023]
Abstract
Telomeres, as physical ends of linear chromosomes, are targets of a number of specific proteins, including primarily telomerase reverse transcriptase. Access of proteins to the telomere may be affected by a number of diverse factors, e.g., protein interaction partners, local DNA or chromatin structures, subcellular localization/trafficking, or simply protein modification. Knowledge of composition of the functional nucleoprotein complex of plant telomeres is only fragmentary. Moreover, the plant telomeric repeat binding proteins that were characterized recently appear to also be involved in non-telomeric processes, e.g., ribosome biogenesis. This interesting finding was not totally unexpected since non-telomeric functions of yeast or animal telomeric proteins, as well as of telomerase subunits, have been reported for almost a decade. Here we summarize known facts about the architecture of plant telomeres and compare them with the well-described composition of telomeres in other organisms.
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Affiliation(s)
- Petra Procházková Schrumpfová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityBrno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrno, Czech Republic
- *Correspondence: Petra Procházková Schrumpfová,
| | - Šárka Schořová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityBrno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i.Brno, Czech Republic
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Schrumpfová PP, Vychodilová I, Hapala J, Schořová Š, Dvořáček V, Fajkus J. Telomere binding protein TRB1 is associated with promoters of translation machinery genes in vivo. PLANT MOLECULAR BIOLOGY 2016; 90:189-206. [PMID: 26597966 DOI: 10.1007/s11103-015-0409-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/16/2015] [Indexed: 05/24/2023]
Abstract
Recently we characterised TRB1, a protein from a single-myb-histone family, as a structural and functional component of telomeres in Arabidopsis thaliana. TRB proteins, besides their ability to bind specifically to telomeric DNA using their N-terminally positioned myb-like domain of the same type as in human shelterin proteins TRF1 or TRF2, also possess a histone-like domain which is involved in protein-protein interactions e.g., with POT1b. Here we set out to investigate the genome-wide localization pattern of TRB1 to reveal its preferential sites of binding to chromatin in vivo and its potential functional roles in the genome-wide context. Our results demonstrate that TRB1 is preferentially associated with promoter regions of genes involved in ribosome biogenesis, in addition to its roles at telomeres. This preference coincides with the frequent occurrence of telobox motifs in the upstream regions of genes in this category, but it is not restricted to the presence of a telobox. We conclude that TRB1 shows a specific genome-wide distribution pattern which suggests its role in regulation of genes involved in biogenesis of the translational machinery, in addition to its preferential telomeric localization.
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Affiliation(s)
- Petra Procházková Schrumpfová
- Mendel Centre for Plant Genomics and Proteomics, CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Ivona Vychodilová
- Mendel Centre for Plant Genomics and Proteomics, CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Jan Hapala
- Mendel Centre for Plant Genomics and Proteomics, CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Šárka Schořová
- Mendel Centre for Plant Genomics and Proteomics, CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Vojtěch Dvořáček
- Mendel Centre for Plant Genomics and Proteomics, CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, 61265, Brno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, 61265, Brno, Czech Republic.
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Dokládal L, Honys D, Rana R, Lee LY, Gelvin SB, Sýkorová E. cDNA Library Screening Identifies Protein Interactors Potentially Involved in Non-Telomeric Roles of Arabidopsis Telomerase. FRONTIERS IN PLANT SCIENCE 2015; 6:985. [PMID: 26617625 PMCID: PMC4641898 DOI: 10.3389/fpls.2015.00985] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/27/2015] [Indexed: 05/27/2023]
Abstract
Telomerase-reverse transcriptase (TERT) plays an essential catalytic role in maintaining telomeres. However, in animal systems telomerase plays additional non-telomeric functional roles. We previously screened an Arabidopsis cDNA library for proteins that interact with the C-terminal extension (CTE) TERT domain and identified a nuclear-localized protein that contains an RNA recognition motif (RRM). This RRM-protein forms homodimers in both plants and yeast. Mutation of the gene encoding the RRM-protein had no detectable effect on plant growth and development, nor did it affect telomerase activity or telomere length in vivo, suggesting a non-telomeric role for TERT/RRM-protein complexes. The gene encoding the RRM-protein is highly expressed in leaf and reproductive tissues. We further screened an Arabidopsis cDNA library for proteins that interact with the RRM-protein and identified five interactors. These proteins are involved in numerous non-telomere-associated cellular activities. In plants, the RRM-protein, both alone and in a complex with its interactors, localizes to nuclear speckles. Transcriptional analyses in wild-type and rrm mutant plants, as well as transcriptional co-analyses, suggest that TERT, the RRM-protein, and the RRM-protein interactors may play important roles in non-telomeric cellular functions.
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Affiliation(s)
- Ladislav Dokládal
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk UniversityBrno, Czech Republic
- Institute of Biophysics – Academy of Sciences of the Czech Republic v.v.i.Brno, Czech Republic
| | - David Honys
- Institute of Experimental Botany – Academy of Sciences of the Czech Republic v.v.i.Prague, Czech Republic
| | - Rajiv Rana
- Institute of Experimental Botany – Academy of Sciences of the Czech Republic v.v.i.Prague, Czech Republic
| | - Lan-Ying Lee
- Department of Biological Sciences, Purdue University, West LafayetteIN, USA
| | - Stanton B. Gelvin
- Department of Biological Sciences, Purdue University, West LafayetteIN, USA
| | - Eva Sýkorová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk UniversityBrno, Czech Republic
- Institute of Biophysics – Academy of Sciences of the Czech Republic v.v.i.Brno, Czech Republic
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Dvořáčková M, Fojtová M, Fajkus J. Chromatin dynamics of plant telomeres and ribosomal genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:18-37. [PMID: 25752316 DOI: 10.1111/tpj.12822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 05/03/2023]
Abstract
Telomeres and genes encoding 45S ribosomal RNA (rDNA) are frequently located adjacent to each other on eukaryotic chromosomes. Although their primary roles are different, they show striking similarities with respect to their features and additional functions. Both genome domains have remarkably dynamic chromatin structures. Both are hypersensitive to dysfunctional histone chaperones, responding at the genomic and epigenomic levels. Both generate non-coding transcripts that, in addition to their epigenetic roles, may induce gross chromosomal rearrangements. Both give rise to chromosomal fragile sites, as their replication is intrinsically problematic. However, at the same time, both are essential for maintenance of genomic stability and integrity. Here we discuss the structural and functional inter-connectivity of telomeres and rDNA, with a focus on recent results obtained in plants.
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Affiliation(s)
- Martina Dvořáčková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
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Amiard S, Olivier M, Allain E, Choi K, Smith-Unna R, Henderson IR, White CI, Gallego ME. Telomere stability and development of ctc1 mutants are rescued by inhibition of EJ recombination pathways in a telomerase-dependent manner. Nucleic Acids Res 2014; 42:11979-91. [PMID: 25274733 PMCID: PMC4231758 DOI: 10.1093/nar/gku897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 09/16/2014] [Accepted: 09/18/2014] [Indexed: 12/11/2022] Open
Abstract
The telomeres of linear eukaryotic chromosomes are protected by caps consisting of evolutionarily conserved nucleoprotein complexes. Telomere dysfunction leads to recombination of chromosome ends and this can result in fusions which initiate chromosomal breakage-fusion-bridge cycles, causing genomic instability and potentially cell death or cancer. We hypothesize that in the absence of the recombination pathways implicated in these fusions, deprotected chromosome ends will instead be eroded by nucleases, also leading to the loss of genes and cell death. In this work, we set out to specifically test this hypothesis in the plant, Arabidopsis. Telomere protection in Arabidopsis implicates KU and CST and their absence leads to chromosome fusions, severe genomic instability and dramatic developmental defects. We have analysed the involvement of end-joining recombination pathways in telomere fusions and the consequences of this on genomic instability and growth. Strikingly, the absence of the multiple end-joining pathways eliminates chromosome fusion and restores normal growth and development to cst ku80 mutant plants. It is thus the chromosomal fusions, per se, which are the underlying cause of the severe developmental defects. This rescue is mediated by telomerase-dependent telomere extension, revealing a competition between telomerase and end-joining recombination proteins for access to deprotected telomeres.
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Affiliation(s)
- Simon Amiard
- Génétique, Reproduction et Développement, UMR CNRS 6293, Clermont Université, INSERM U1103, Aubière, France
| | - Margaux Olivier
- Génétique, Reproduction et Développement, UMR CNRS 6293, Clermont Université, INSERM U1103, Aubière, France
| | - Elisabeth Allain
- Génétique, Reproduction et Développement, UMR CNRS 6293, Clermont Université, INSERM U1103, Aubière, France Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Kyuha Choi
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | | | - Ian R Henderson
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Charles I White
- Génétique, Reproduction et Développement, UMR CNRS 6293, Clermont Université, INSERM U1103, Aubière, France
| | - Maria Eugenia Gallego
- Génétique, Reproduction et Développement, UMR CNRS 6293, Clermont Université, INSERM U1103, Aubière, France
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Renfrew KB, Song X, Lee JR, Arora A, Shippen DE. POT1a and components of CST engage telomerase and regulate its activity in Arabidopsis. PLoS Genet 2014; 10:e1004738. [PMID: 25329641 PMCID: PMC4199523 DOI: 10.1371/journal.pgen.1004738] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 09/06/2014] [Indexed: 11/18/2022] Open
Abstract
Protection of Telomeres 1 (POT1) is a conserved nucleic acid binding protein implicated in both telomere replication and chromosome end protection. We previously showed that Arabidopsis thaliana POT1a associates with the TER1 telomerase RNP, and is required for telomere length maintenance in vivo. Here we further dissect the function of POT1a and explore its interplay with the CST (CTC1/STN1/TEN1) telomere complex. Analysis of pot1a null mutants revealed that POT1a is not required for telomerase recruitment to telomeres, but is required for telomerase to maintain telomere tracts. We show that POT1a stimulates the synthesis of long telomere repeat arrays by telomerase, likely by enhancing repeat addition processivity. We demonstrate that POT1a binds STN1 and CTC1 in vitro, and further STN1 and CTC1, like POT1a, associate with enzymatically active telomerase in vivo. Unexpectedly, the in vitro interaction of STN1 with TEN1 and POT1a was mutually exclusive, indicating that POT1a and TEN1 may compete for the same binding site on STN1 in vivo. Finally, unlike CTC1 and STN1, TEN1 was not associated with active telomerase in vivo, consistent with our previous data showing that TEN1 negatively regulates telomerase enzyme activity. Altogether, our data support a two-state model in which POT1a promotes an extendable telomere state via contacts with the telomerase RNP as well as STN1 and CTC1, while TEN1 opposes these functions.
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Affiliation(s)
- Kyle B. Renfrew
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Xiangyu Song
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Jung Ro Lee
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Amit Arora
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Dorothy E. Shippen
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
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45
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Fojtová M, Fajkus J. Epigenetic Regulation of Telomere Maintenance. Cytogenet Genome Res 2014; 143:125-35. [DOI: 10.1159/000360775] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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