1
|
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 2024:100890. [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] [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.
Collapse
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.
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Achrem M, Szućko I, Kalinka A. The epigenetic regulation of centromeres and telomeres in plants and animals. COMPARATIVE CYTOGENETICS 2020; 14:265-311. [PMID: 32733650 PMCID: PMC7360632 DOI: 10.3897/compcytogen.v14i2.51895] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/18/2020] [Indexed: 05/10/2023]
Abstract
The centromere is a chromosomal region where the kinetochore is formed, which is the attachment point of spindle fibers. Thus, it is responsible for the correct chromosome segregation during cell division. Telomeres protect chromosome ends against enzymatic degradation and fusions, and localize chromosomes in the cell nucleus. For this reason, centromeres and telomeres are parts of each linear chromosome that are necessary for their proper functioning. More and more research results show that the identity and functions of these chromosomal regions are epigenetically determined. Telomeres and centromeres are both usually described as highly condensed heterochromatin regions. However, the epigenetic nature of centromeres and telomeres is unique, as epigenetic modifications characteristic of both eu- and heterochromatin have been found in these areas. This specificity allows for the proper functioning of both regions, thereby affecting chromosome homeostasis. This review focuses on demonstrating the role of epigenetic mechanisms in the functioning of centromeres and telomeres in plants and animals.
Collapse
Affiliation(s)
- Magdalena Achrem
- Institute of Biology, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
- Molecular Biology and Biotechnology Center, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
| | - Izabela Szućko
- Institute of Biology, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
- Molecular Biology and Biotechnology Center, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
| | - Anna Kalinka
- Institute of Biology, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
- Molecular Biology and Biotechnology Center, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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.
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
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.
Collapse
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.
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Jaiswal A, Lakshmi P. Molecular inhibition of telomerase recruitment using designer peptides: anin silicoapproach. J Biomol Struct Dyn 2014; 33:1442-59. [DOI: 10.1080/07391102.2014.953207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
13
|
Procházková Schrumpfová P, Vychodilová I, Dvořáčková M, Majerská J, Dokládal L, Schořová Š, Fajkus J. Telomere repeat binding proteins are functional components of Arabidopsis telomeres and interact with telomerase. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 77:770-81. [PMID: 24397874 PMCID: PMC4282523 DOI: 10.1111/tpj.12428] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/06/2013] [Accepted: 12/23/2013] [Indexed: 05/19/2023]
Abstract
Although telomere-binding proteins constitute an essential part of telomeres, in vivo data indicating the existence of a structure similar to mammalian shelterin complex in plants are limited. Partial characterization of a number of candidate proteins has not identified true components of plant shelterin or elucidated their functional mechanisms. Telomere repeat binding (TRB) proteins from Arabidopsis thaliana bind plant telomeric repeats through a Myb domain of the telobox type in vitro, and have been shown to interact with POT1b (Protection of telomeres 1). Here we demonstrate co-localization of TRB1 protein with telomeres in situ using fluorescence microscopy, as well as in vivo interaction using chromatin immunoprecipitation. Classification of the TRB1 protein as a component of plant telomeres is further confirmed by the observation of shortening of telomeres in knockout mutants of the trb1 gene. Moreover, TRB proteins physically interact with plant telomerase catalytic subunits. These findings integrate TRB proteins into the telomeric interactome of A. thaliana.
Collapse
Affiliation(s)
- Petra Procházková Schrumpfová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
- Functional Genomics and Proteomics, CEITEC National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
- *For correspondence (e-mails or )
| | - Ivona Vychodilová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
- Functional Genomics and Proteomics, CEITEC National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
| | - Martina Dvořáčková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republicv.v.i, Královopolská 135, Brno, CZ, 61265, Czech Republic
| | - Jana Majerská
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
- †Swiss Institute for Experimental Cancer Research, Ecole Polytechnique Fédérale de LausanneStation 19, 1015, Lausanne, Switzerland
| | - Ladislav Dokládal
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republicv.v.i, Královopolská 135, Brno, CZ, 61265, Czech Republic
| | - Šárka Schořová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
- Functional Genomics and Proteomics, CEITEC National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
- Functional Genomics and Proteomics, CEITEC National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityKamenice 5, Brno, CZ, 62500, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republicv.v.i, Královopolská 135, Brno, CZ, 61265, Czech Republic
- *For correspondence (e-mails or )
| |
Collapse
|
14
|
Identification of 30 MYB transcription factor genes and analysis of their expression during abiotic stress in peanut (Arachis hypogaea L.). Gene 2014; 533:332-45. [DOI: 10.1016/j.gene.2013.08.092] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 08/26/2013] [Accepted: 08/28/2013] [Indexed: 01/06/2023]
|
15
|
Zhang L, Zhao G, Jia J, Liu X, Kong X. Molecular characterization of 60 isolated wheat MYB genes and analysis of their expression during abiotic stress. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:203-14. [PMID: 21934119 PMCID: PMC3245462 DOI: 10.1093/jxb/err264] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The proteins of the MYB superfamily play central roles in developmental processes and defence responses in plants. Sixty unique wheat MYB genes that contain full-length cDNA sequences were isolated. These 60 genes were grouped into three categories, namely one R1R2R3-MYB, 22 R2R3-MYBs, and 37 MYB-related members. The sequence composition of the R2 and R3 repeats was conserved among the 22 wheat R2R3-MYB proteins. Phylogenetic comparison of the members of this superfamily among wheat, rice, and Arabidopsis revealed that the putative functions of some wheat MYB proteins were clustered into the Arabidopsis functional clades. Tissue-specific expression profiles showed that most of the wheat MYB genes were expressed in all of the tissues examined, suggesting that wheat MYB genes take part in multiple cellular processes. The expression analysis during abiotic stress identified a group of MYB genes that respond to one or more stress treatments. The overexpression of a salt-inducible gene, TaMYB32, enhanced the tolerance to salt stress in transgenic Arabidopsis. This study is the first comprehensive study of the MYB gene family in Triticeae.
Collapse
Affiliation(s)
| | | | | | | | - Xiuying Kong
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
16
|
QTL Mapping and Candidate Gene Analysis of Telomere Length Control Factors in Maize (Zea mays L.). G3-GENES GENOMES GENETICS 2011; 1:437-50. [PMID: 22384354 PMCID: PMC3276162 DOI: 10.1534/g3.111.000703] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 09/16/2011] [Indexed: 11/30/2022]
Abstract
Telomere length is a quantitative trait important for many cellular functions. Failure to regulate telomere length contributes to genomic instability, cellular senescence, cancer, and apoptosis in humans, but the functional significance of telomere regulation in plants is much less well understood. To gain a better understanding of telomere biology in plants, we used quantitative trait locus (QTL) mapping to identify genetic elements that control telomere length variation in maize (Zea mays L.). For this purpose, we measured the median and mean telomere lengths from 178 recombinant inbred lines of the IBM mapping population and found multiple regions that collectively accounted for 33–38% of the variation in telomere length. Two-way analysis of variance revealed interaction between the quantitative trait loci at genetic bin positions 2.09 and 5.04. Candidate genes within these and other significant QTL intervals, along with select genes known a priori to regulate telomere length, were tested for correlations between expression levels and telomere length in the IBM population and diverse inbred lines by quantitative real-time PCR. A slight but significant positive correlation between expression levels and telomere length was observed for many of the candidate genes, but Ibp2 was a notable exception, showing instead a negative correlation. A rad51-like protein (TEL-MD_5.04) was strongly supported as a candidate gene by several lines of evidence. Our results highlight the value of QTL mapping plus candidate gene expression analysis in a genetically diverse model system for telomere research.
Collapse
|
17
|
Dvorácková M, Rossignol P, Shaw PJ, Koroleva OA, Doonan JH, Fajkus J. AtTRB1, a telomeric DNA-binding protein from Arabidopsis, is concentrated in the nucleolus and shows highly dynamic association with chromatin. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 61:637-49. [PMID: 19947985 DOI: 10.1111/j.1365-313x.2009.04094.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
AtTRB1, 2 and 3 are members of the SMH (single Myb histone) protein family, which comprises double-stranded DNA-binding proteins that are specific to higher plants. They are structurally conserved, containing a Myb domain at the N-terminus, a central H1/H5-like domain and a C-terminally located coiled-coil domain. AtTRB1, 2 and 3 interact through their Myb domain specifically with telomeric double-stranded DNA in vitro, while the central H1/H5-like domain interacts non-specifically with DNA sequences and mediates protein-protein interactions. Here we show that AtTRB1, 2 and 3 preferentially localize to the nucleus and nucleolus during interphase. Both the central H1/H5-like domain and the Myb domain from AtTRB1 can direct a GFP fusion protein to the nucleus and nucleolus. AtTRB1-GFP localization is cell cycle-regulated, as the level of nuclear-associated GFP diminishes during mitotic entry and GFP progressively re-associates with chromatin during anaphase/telophase. Using fluorescence recovery after photobleaching and fluorescence loss in photobleaching, we determined the dynamics of AtTRB1 interactions in vivo. The results reveal that AtTRB1 interaction with chromatin is regulated at two levels at least, one of which is coupled with cell-cycle progression, with the other involving rapid exchange.
Collapse
Affiliation(s)
- Martina Dvorácková
- Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
| | | | | | | | | | | |
Collapse
|
18
|
Linger BR, Price CM. Conservation of telomere protein complexes: shuffling through evolution. Crit Rev Biochem Mol Biol 2009; 44:434-46. [PMID: 19839711 DOI: 10.3109/10409230903307329] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The rapid evolution of telomere proteins has hindered identification of orthologs from diverse species and created the impression that certain groups of eukaryotes have largely non-overlapping sets of telomere proteins. However, the recent identification of additional telomere proteins from various model organisms has dispelled this notion by expanding our understanding of the composition, architecture and range of telomere protein complexes present in individual species. It is now apparent that versions of the budding yeast CST complex and mammalian shelterin are present in multiple phyla. While the precise subunit composition and architecture of these complexes vary between species, the general function is often conserved. Despite the overall conservation of telomere protein complexes, there is still considerable species-specific variation, with some organisms having lost a particular subunit or even an entire complex. In some cases, complex components appear to have migrated between the telomere and the telomerase RNP. Finally, gene duplication has created telomere protein paralogs with novel functions. While one paralog may be part of a conserved telomere protein complex and have the expected function, the other paralog may serve in a completely different aspect of telomere biology.
Collapse
Affiliation(s)
- Benjamin R Linger
- Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, OH 45267-0521, USA
| | | |
Collapse
|
19
|
Single-Myb-histone proteins from Arabidopsis thaliana: a quantitative study of telomere-binding specificity and kinetics. Biochem J 2009; 419:221-8, 2 p following 228. [DOI: 10.1042/bj20082195] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Proteins that bind telomeric DNA modulate the structure of chromosome ends and control telomere function and maintenance. It has been shown that AtTRB (Arabidopsis thaliana telomere-repeat-binding factor) proteins from the SMH (single-Myb-histone) family selectively bind double-stranded telomeric DNA and interact with the telomeric protein AtPOT1b (A. thaliana protection of telomeres 1b), which is involved in telomere capping. In the present study, we performed the first quantitative DNA-binding study of this plant-specific family of proteins. Interactions of full-length proteins AtTRB1 and AtTRB3 with telomeric DNA were analysed by electrophoretic mobility-shift assay, fluorescence anisotropy and surface plasmon resonance to reveal their binding stoichiometry and kinetics. Kinetic analyses at different salt conditions enabled us to estimate the electrostatic component of binding and explain different affinities of the two proteins to telomeric DNA. On the basis of available data, a putative model explaining the binding stoichiometry and the protein arrangement on telomeric DNA is presented.
Collapse
|
20
|
Mozgová I, Schrumpfová PP, Hofr C, Fajkus J. Functional characterization of domains in AtTRB1, a putative telomere-binding protein in Arabidopsis thaliana. PHYTOCHEMISTRY 2008; 69:1814-9. [PMID: 18479720 DOI: 10.1016/j.phytochem.2008.04.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 03/24/2008] [Accepted: 04/01/2008] [Indexed: 05/24/2023]
Abstract
Telomeres are nucleoprotein structures ensuring the stability of eukaryotic chromosome ends. Two protein families, TRFL (TFL-Like) and SMH (Single-Myb-Histone), containing a specific telobox motif in their Myb domain, have been identified as potential candidates involved in a functional nucleoprotein structure analogous to human "shelterin" at plant telomeres. We analyze the DNA-protein interaction of the full-length and truncated variants of AtTRB1, a SMH-family member with a typical structure: N-terminal Myb domain, central H1/5 domain and C-terminal coiled-coil. We show that preferential interaction of AtTRB1 with double-stranded telomeric DNA is mediated by the Myb domain, while the H1/5 domain is involved in non-specific DNA-protein interaction and in the multimerization of AtTRB1.
Collapse
Affiliation(s)
- Iva Mozgová
- Department of Functional Genomics and Proteomics, Institute of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
| | | | | | | |
Collapse
|