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Fanara S, Schloesser M, Joris M, De Franco S, Vandevenne M, Kerff F, Hanikenne M, Motte P. The Arabidopsis SR45 splicing factor bridges the splicing machinery and the exon-exon junction complex. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:2280-2298. [PMID: 38180875 DOI: 10.1093/jxb/erae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 01/04/2024] [Indexed: 01/07/2024]
Abstract
The Arabidopsis splicing factor serine/arginine-rich 45 (SR45) contributes to several biological processes. The sr45-1 loss-of-function mutant exhibits delayed root development, late flowering, unusual numbers of floral organs, shorter siliques with decreased seed sets, narrower leaves and petals, and altered metal distribution. SR45 bears a unique RNA recognition motif (RRM) flanked by one serine/arginine-rich (RS) domain on both sides. Here, we studied the function of each SR45 domains by examining their involvement in: (i) the spatial distribution of SR45; (ii) the establishment of a protein-protein interaction network including spliceosomal and exon-exon junction complex (EJC) components; and (iii) the RNA binding specificity. We report that the endogenous SR45 promoter is active during vegetative and reproductive growth, and that the SR45 protein localizes in the nucleus. We demonstrate that the C-terminal arginine/serine-rich domain is a determinant of nuclear localization. We show that the SR45 RRM domain specifically binds purine-rich RNA motifs via three residues (H101, H141, and Y143), and is also involved in protein-protein interactions. We further show that SR45 bridges both mRNA splicing and surveillance machineries as a partner of EJC core components and peripheral factors, which requires phosphoresidues probably phosphorylated by kinases from both the CLK and SRPK families. Our findings provide insights into the contribution of each SR45 domain to both spliceosome and EJC assemblies.
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Affiliation(s)
- Steven Fanara
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000, Liège, Belgium
| | - Marie Schloesser
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000, Liège, Belgium
| | - Marine Joris
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000, Liège, Belgium
| | - Simona De Franco
- InBioS-Center for Protein Engineering, Laboratory of Biological Macromolecules, University of Liège, 4000, Liège, Belgium
| | - Marylène Vandevenne
- InBioS-Center for Protein Engineering, Laboratory of Biological Macromolecules, University of Liège, 4000, Liège, Belgium
| | - Frédéric Kerff
- InBioS-Center for Protein Engineering, Laboratory of Crystallography, University of Liège, 4000, Liège, Belgium
| | - Marc Hanikenne
- InBioS-PhytoSystems, Translational Plant Biology, University of Liège, 4000, Liège, Belgium
| | - Patrick Motte
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000, Liège, Belgium
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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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3
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Identification of Pri-miRNA Stem-Loop Interacting Proteins in Plants Using a Modified Version of the Csy4 CRISPR Endonuclease. Int J Mol Sci 2022; 23:ijms23168961. [PMID: 36012225 PMCID: PMC9409100 DOI: 10.3390/ijms23168961] [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: 06/24/2022] [Revised: 08/05/2022] [Accepted: 08/09/2022] [Indexed: 11/17/2022] Open
Abstract
Regulation at the RNA level by RNA-binding proteins (RBPs) and microRNAs (miRNAs) is key to coordinating eukaryotic gene expression. In plants, the importance of miRNAs is highlighted by severe developmental defects in mutants impaired in miRNA biogenesis. MiRNAs are processed from long primary-microRNAs (pri-miRNAs) with internal stem-loop structures by endonucleolytic cleavage. The highly structured stem-loops constitute the basis for the extensive regulation of miRNA biogenesis through interaction with RBPs. However, trans-acting regulators of the biogenesis of specific miRNAs are largely unknown in plants. Therefore, we exploit an RNA-centric approach based on modified versions of the conditional CRISPR nuclease Csy4* to pull down interactors of the Arabidopsis pri-miR398b stem-loop (pri-miR398b-SL) in vitro. We designed three epitope-tagged versions of the inactive Csy4* for the immobilization of the protein together with the pri-miR398b-SL bait on high affinity matrices. After incubation with nucleoplasmic extracts from Arabidopsis and extensive washing, pri-miR398b-SL, along with its specifically bound proteins, were released by re-activating the cleavage activity of the Csy4* upon the addition of imidazole. Co-purified proteins were identified via quantitative mass spectrometry and data sets were compared. In total, we identified more than 400 different proteins, of which 180 are co-purified in at least two out of three independent Csy4*-based RNA pulldowns. Among those, the glycine-rich RNA-binding protein AtRZ-1a was identified in all pulldowns. To analyze the role of AtRZ-1a in miRNA biogenesis, we determined the miR398 expression level in the atrz-1a mutant. Indeed, the absence of AtRZ-1a caused a decrease in the steady-state level of mature miR398 with a concomitant reduction in pri-miR398b levels. Overall, we show that our modified Csy4*-based RNA pulldown strategy is suitable to identify new trans-acting regulators of miRNA biogenesis and provides new insights into the post-transcriptional regulation of miRNA processing by plant RBPs.
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Strini EJ, Bertolino LT, San Martin JAB, Souza HAO, Pessotti F, Pinoti VF, Ferreira PB, De Paoli HC, Lubini G, Del-Bem LE, Quiapim AC, Mondin M, Araujo APU, Eloy NB, Barberis M, Goldman MHS. Stigma/Style Cell-Cycle Inhibitor 1, a Regulator of Cell Proliferation, Interacts With a Specific 14-3-3 Protein and Is Degraded During Cell Division. FRONTIERS IN PLANT SCIENCE 2022; 13:857745. [PMID: 35444668 PMCID: PMC9013909 DOI: 10.3389/fpls.2022.857745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
The final shape and size of plant organs are determined by a network of genes that modulate cell proliferation and expansion. Among those, SCI1 (Stigma/style Cell-cycle Inhibitor 1) functions by inhibiting cell proliferation during pistil development. Alterations in SCI1 expression levels can lead to remarkable stigma/style size changes. Recently, we demonstrated that SCI1 starts to be expressed at the specification of the Nicotiana tabacum floral meristem and is expressed at all floral meristematic cells. To elucidate how SCI1 regulates cell proliferation, we screened a stigma/style cDNA library through the yeast two-hybrid (Y2H) system, using SCI1 as bait. Among the interaction partners, we identified the 14-3-3D protein of the Non-Epsilon group. The interaction between SCI1 and 14-3-3D was confirmed by pulldown and co-immunoprecipitation experiments. 14-3-3D forms homo- and heterodimers in the cytoplasm of plant cells and interacts with SCI1 in the nucleus, as demonstrated by Bimolecular Fluorescence Complementation (BiFC). Analyses of SCI1-GFP fluorescence through the cell-cycle progression revealed its presence in the nucleoli during interphase and prophase. At metaphase, SCI1-GFP fluorescence faded and was no longer detected at anaphase, reappearing at telophase. Upon treatment with the 26S proteasome inhibitor MG132, SCI1-GFP was stabilized during cell division. Site-directed mutagenesis of seven serines into alanines in the predicted 14-3-3 binding sites on the SCI1 sequence prevented its degradation during mitosis. Our results demonstrate that SCI1 degradation at the beginning of metaphase is dependent on the phosphorylation of serine residues and on the action of the 26S proteasome. We concluded that SCI1 stability/degradation is cell-cycle regulated, consistent with its role in fine-tuning cell proliferation.
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Affiliation(s)
- Edward J. Strini
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- PPG-Genética, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Lígia T. Bertolino
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- PPG-Genética, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Juca A. B. San Martin
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Hebréia A. O. Souza
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Francine Pessotti
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- PPG-Genética, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Vitor F. Pinoti
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- PPG-Genética, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Pedro B. Ferreira
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- PPG-Genética, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Henrique C. De Paoli
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- PPG-Genética, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Greice Lubini
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- PPG-Genética, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Luiz-Eduardo Del-Bem
- Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Andréa C. Quiapim
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Mateus Mondin
- Departamento de Genética, Escola Superior de Agricultura Luiz de Queiroz, University of São Paulo, Piracicaba, Brazil
| | - Ana Paula U. Araujo
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Nubia B. Eloy
- Departamento de Ciências Biológicas, Escola Superior de Agricultura Luiz de Queiroz, University of São Paulo, Piracicaba, Brazil
| | - Matteo Barberis
- Systems Biology, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
- Centre for Mathematical and Computational Biology, CMCB, University of Surrey, Guildford, United Kingdom
- Synthetic Systems Biology and Nuclear Organization, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Maria Helena S. Goldman
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- PPG-Genética, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
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5
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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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6
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Kachaev ZM, Ivashchenko SD, Kozlov EN, Lebedeva LA, Shidlovskii YV. Localization and Functional Roles of Components of the Translation Apparatus in the Eukaryotic Cell Nucleus. Cells 2021; 10:3239. [PMID: 34831461 PMCID: PMC8623629 DOI: 10.3390/cells10113239] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/11/2021] [Accepted: 11/16/2021] [Indexed: 12/15/2022] Open
Abstract
Components of the translation apparatus, including ribosomal proteins, have been found in cell nuclei in various organisms. Components of the translation apparatus are involved in various nuclear processes, particularly those associated with genome integrity control and the nuclear stages of gene expression, such as transcription, mRNA processing, and mRNA export. Components of the translation apparatus control intranuclear trafficking; the nuclear import and export of RNA and proteins; and regulate the activity, stability, and functional recruitment of nuclear proteins. The nuclear translocation of these components is often involved in the cell response to stimulation and stress, in addition to playing critical roles in oncogenesis and viral infection. Many components of the translation apparatus are moonlighting proteins, involved in integral cell stress response and coupling of gene expression subprocesses. Thus, this phenomenon represents a significant interest for both basic and applied molecular biology. Here, we provide an overview of the current data regarding the molecular functions of translation factors and ribosomal proteins in the cell nucleus.
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Affiliation(s)
- Zaur M. Kachaev
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (Z.M.K.); (S.D.I.); (E.N.K.); (L.A.L.)
- Center for Genetics and Life Science, Sirius University of Science and Technology, 354340 Sochi, Russia
| | - Sergey D. Ivashchenko
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (Z.M.K.); (S.D.I.); (E.N.K.); (L.A.L.)
| | - Eugene N. Kozlov
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (Z.M.K.); (S.D.I.); (E.N.K.); (L.A.L.)
| | - Lyubov A. Lebedeva
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (Z.M.K.); (S.D.I.); (E.N.K.); (L.A.L.)
| | - Yulii V. Shidlovskii
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (Z.M.K.); (S.D.I.); (E.N.K.); (L.A.L.)
- Center for Genetics and Life Science, Sirius University of Science and Technology, 354340 Sochi, Russia
- Department of Biology and General Genetics, Sechenov First Moscow State Medical University (Sechenov University), 119992 Moscow, Russia
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Ke YT, Lin KF, Gu CH, Yeh CH. Molecular Characterization and Expression Profile of PaCOL1, a CONSTANS-like Gene in Phalaenopsis Orchid. PLANTS (BASEL, SWITZERLAND) 2020; 9:plants9010068. [PMID: 31947959 PMCID: PMC7020484 DOI: 10.3390/plants9010068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
CONSTANS (CO) and CONSTANS-like (COL) genes play important roles in coalescing signals from photoperiod and temperature pathways. However, the mechanism of CO and COLs involved in regulating the developmental stage transition and photoperiod/temperature senescing remains unclear. In this study, we identified a COL ortholog gene from the Taiwan native orchid Phalaenopsis aphrodite. The Phalaenopsis aphrodite CONSTANS-like 1 (PaCOL1) belongs to the B-box protein family and functions in the nucleus and cytosol. Expression profile analysis of Phalaenopsis aphrodite revealed that PaCOL1 was significantly expressed in leaves, but its accumulation was repressed during environmental temperature shifts. We found a differential profile for PaCOL1 accumulation, with peak accumulation at late afternoon and at the middle of the night. Arabidopsis with PaCOL1 overexpression showed earlier flowering under short-day (SD) conditions (8 h/23 °C light and 16 h/23 °C dark) but similar flowering time under long-day (LD) conditions (16 h/23 °C light and 8 h/23 °C dark). Transcriptome sequencing revealed several genes upregulated in PaCOL1-overexpressing Arabidopsis plants that were previously involved in flowering regulation of the photoperiod pathway. Yeast two-hybrid (Y2H) analysis and bimolecular fluorescence complementation (BiFC) analysis revealed that PaCOL1 could interact with a crucial clock-associated regulator, AtCCA1, and a flowering repressor, AtFLC. Furthermore, expressing PaCOL1 in cca1.lhy partially reversed the mutant flowering time under photoperiod treatment, which confirms the role of PaCOL1 function in the rhythmic associated factors for modulating flowering.
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The DEAD-box RNA helicase eIF4A regulates plant development and interacts with the hnRNP LIF2L1 in Physcomitrella patens. Mol Genet Genomics 2019; 295:373-389. [PMID: 31781862 DOI: 10.1007/s00438-019-01628-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 11/20/2019] [Indexed: 12/26/2022]
Abstract
eIF4A is a RNA-stimulated ATPase and helicase. Besides its key role in regulating cap-dependent translation initiation in eukaryotes, it also performs specific functions in regulating cell cycle progression, plant growth and abiotic stress tolerance. Flowering plants encode three eIF4A paralogues, eIF4A1, eIF4A2 and eIF4A3 that share conserved sequence motifs but differ in functions. To date, however, no information is available on eIF4A in basal land plants. In this study we report that genome of the moss Physcomitrella patens encodes multiple eIF4A genes. The encoded proteins possess the highly conserved motifs characteristic of the DEAD box helicases. Spatial expression analysis shows these genes to be ubiquitously expressed in all tissue types with Pp3c6_1080V3.1 showing high expression in filamentous protonemata. Targeted deletion of conserved core motifs in Pp3c6_1080V3.1 slowed protonemata growth and resulted in dwarfing of leafy gametophores suggesting a role for Pp3c6_1080V3.1 in regulating cell division/elongation. Rapid and strong induction of Pp3c6_1080V3.1 under salt stress and slow recovery of knockout plants upon exposure to high salt further suggest Pp3c6_1080V3.1 to be involved in stress management in P. patens. Protein-protein interaction studies that show Pp3c6_1080V3.1 to interact with the Physcomitrella heterogenous ribonucleoprotein, LIF2L1, a transcriptional regulator of stress-responsive genes in Arabidopsis. The results presented in this study provide insight into evolutionary conserved functions of eIF4A and shed light on the novel link between eIF4A activities and stress mitigation pathways/RNA metabolic processes in P. patens.
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9
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Lee TA, Bailey-Serres J. Integrative Analysis from the Epigenome to Translatome Uncovers Patterns of Dominant Nuclear Regulation during Transient Stress. THE PLANT CELL 2019; 31:2573-2595. [PMID: 31519798 PMCID: PMC6881120 DOI: 10.1105/tpc.19.00463] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/21/2019] [Accepted: 09/12/2019] [Indexed: 05/19/2023]
Abstract
Gene regulation is a dynamic process involving changes ranging from the remodeling of chromatin to preferential translation. To understand integrated nuclear and cytoplasmic gene regulatory dynamics, we performed a survey spanning the epigenome to translatome of Arabidopsis (Arabidopsis thaliana) seedlings in response to hypoxia and reoxygenation. This included chromatin assays (examining histones, accessibility, RNA polymerase II [RNAPII], and transcription factor binding) and three RNA assays (nuclear, polyadenylated, and ribosome-associated). Dynamic patterns of nuclear regulation distinguished stress-induced and growth-associated mRNAs. The rapid upregulation of hypoxia-responsive gene transcripts and their preferential translation were generally accompanied by increased chromatin accessibility, RNAPII engagement, and reduced Histone 2A.Z association. Hypoxia promoted a progressive upregulation of heat stress transcripts, as evidenced by RNAPII binding and increased nuclear RNA, with polyadenylated RNA levels only elevated after prolonged stress or reoxygenation. Promoters of rapidly versus progressively upregulated genes were enriched for cis-elements of ethylene-responsive and heat shock factor transcription factors, respectively. Genes associated with growth, including many encoding cytosolic ribosomal proteins, underwent distinct histone modifications, yet retained RNAPII engagement and accumulated nuclear transcripts during the stress. Upon reaeration, progressively upregulated and growth-associated gene transcripts were rapidly mobilized to ribosomes. Thus, multilevel nuclear regulation of nucleosomes, transcript synthesis, accumulation, and translation tailor transient stress responses.plantcell;31/11/2573/FX1F1fx1.
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Affiliation(s)
- Travis A Lee
- Center for Plant Cell Biology and Botany and Plant Sciences Department, University of California, Riverside, California 92521
| | - Julia Bailey-Serres
- Center for Plant Cell Biology and Botany and Plant Sciences Department, University of California, Riverside, California 92521
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10
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Zhang Y, Deng G, Fan W, Yuan L, Wang H, Zhang P. NHX1 and eIF4A1-stacked transgenic sweetpotato shows enhanced tolerance to drought stress. PLANT CELL REPORTS 2019; 38:1427-1438. [PMID: 31396684 DOI: 10.1007/s00299-019-02454-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/29/2019] [Indexed: 06/10/2023]
Abstract
Co-expression of Na+/H+ antiporter NHX1 and DEAD-box RNA helicase eIF4A1 from Arabidopsis positively regulates drought stress tolerance by improving ROS scavenging capacity and maintaining membrane integrity in sweetpotato. Plants evolve multiple strategies for stress adaptation in nature. To improve sweetpotato resistance to drought stress, transgenic sweetpotato plants overexpressing the Arabidopsis Na+/H+ antiporter, NHX1, and the translation initiation factor elF4A1 were characterized for phenotypic traits and physiological performance. Without drought treatment, the NHX1-elF4A1 stacked lines (NE lines) showed normal, vigorous growth comparable to the WT plants. The NE plants showed dense green foliage with delayed leaf senescence and developed more roots than WT plants under drought treatment for 18 days. Compared to WT plants, higher level of reactive oxygen scavenging capacity was detected in NE lines as indicated by reduced H2O2 accumulation as well as increased superoxide dismutase activity and proline content. The relative ion leakage and malondialdehyde content were reduced in NE plants, indicating improved maintenance of intact membranes system. Both NE plants and NHX1-overexpressing plants (N lines) showed larger aerial parts and well-developed root system compared to WT plants under the drought stress conditions, likely due to the improved antioxidant capacity. The NE plants showed better ROS scavenging than N-line plants. All N- and NE-line plants produced normal storage roots with similar yields as WT in the field under normal growth conditions. These results demonstrated the potential to enhance sweetpotato productivity through stacking genes that are involved in ion compartmentalization and translation initiation.
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Affiliation(s)
- Yandi Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gaifang Deng
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Weijuan Fan
- Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Plant Science Research Center, Chinese Academy of Science, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
| | - Ling Yuan
- Department of Plant and Soil Sciences and Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY, 40546, USA
| | - Hongxia Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai, 200032, China.
- Department of Plant and Soil Sciences and Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY, 40546, USA.
| | - Peng Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai, 200032, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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11
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Daras G, Rigas S, Alatzas A, Samiotaki M, Chatzopoulos D, Tsitsekian D, Papadaki V, Templalexis D, Banilas G, Athanasiadou AM, Kostourou V, Panayotou G, Hatzopoulos P. LEFKOTHEA Regulates Nuclear and Chloroplast mRNA Splicing in Plants. Dev Cell 2019; 50:767-779.e7. [PMID: 31447263 DOI: 10.1016/j.devcel.2019.07.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 04/27/2019] [Accepted: 07/25/2019] [Indexed: 12/14/2022]
Abstract
Eukaryotic organisms accomplish the removal of introns to produce mature mRNAs through splicing. Nuclear and organelle splicing mechanisms are distinctively executed by spliceosome and group II intron complex, respectively. Here, we show that LEFKOTHEA, a nuclear encoded RNA-binding protein, participates in chloroplast group II intron and nuclear pre-mRNA splicing. Transiently optimized LEFKOTHEA nuclear activity is fundamental for plant growth, whereas the loss of function abruptly arrests embryogenesis. Nucleocytoplasmic partitioning and chloroplast allocation are efficiently balanced via functional motifs in LEFKOTHEA polypeptide. In the context of nuclear-chloroplast coevolution, our results provide a strong paradigm of the convergence of RNA maturation mechanisms in the nucleus and chloroplasts to coordinately regulate gene expression and effectively control plant growth.
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Affiliation(s)
- Gerasimos Daras
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Stamatis Rigas
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Anastasios Alatzas
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Martina Samiotaki
- Institute for Bioinnovation, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
| | | | - Dikran Tsitsekian
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Vassiliki Papadaki
- Institute for Bioinnovation, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
| | | | - Georgios Banilas
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | | | - Vassiliki Kostourou
- Institute for Bioinnovation, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
| | - George Panayotou
- Institute for Bioinnovation, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
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12
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Gong P, Li J, He C. Exon junction complex (EJC) core genes play multiple developmental roles in Physalis floridana. PLANT MOLECULAR BIOLOGY 2018; 98:545-563. [PMID: 30426309 PMCID: PMC6280879 DOI: 10.1007/s11103-018-0795-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
KEY MESSAGE Molecular and functional characterization of four gene families of the Physalis exon junction complex (EJC) core improved our understanding of the evolution and function of EJC core genes in plants. The exon junction complex (EJC) plays significant roles in posttranscriptional regulation of genes in eukaryotes. However, its developmental roles in plants are poorly known. We characterized four EJC core genes from Physalis floridana that were named PFMAGO, PFY14, PFeIF4AIII and PFBTZ. They shared a similar phylogenetic topology and were expressed in all examined organs. PFMAGO, PFY14 and PFeIF4AIII were localized in both the nucleus and cytoplasm while PFBTZ was mainly localized in the cytoplasm. No protein homodimerization was observed, but they could form heterodimers excluding the PFY14-PFBTZ heterodimerization. Virus-induced gene silencing (VIGS) of PFMAGO or PFY14 aborted pollen development and resulted in low plant survival due to a leaf-blight-like phenotype in the shoot apex. Carpel functionality was also impaired in the PFY14 knockdowns, whereas pollen maturation was uniquely affected in PFBTZ-VIGS plants. Once PFeIF4AIII was strongly downregulated, plant survival was reduced via a decomposing root collar after flowering and Chinese lantern morphology was distorted. The expression of Physalis orthologous genes in the DYT1-TDF1-AMS-bHLH91 regulatory cascade that is associated with pollen maturation was significantly downregulated in PFMAGO-, PFY14- and PFBTZ-VIGS flowers. Intron-retention in the transcripts of P. floridana dysfunctional tapetum1 (PFDYT1) occurred in these mutated flowers. Additionally, the expression level of WRKY genes in defense-related pathways in the shoot apex of PFMAGO- or PFY14-VIGS plants and in the root collar of PFeIF4AIII-VIGS plants was significantly downregulated. Taken together, the Physalis EJC core genes play multiple roles including a conserved role in male fertility and newly discovered roles in Chinese lantern development, carpel functionality and defense-related processes. These data increase our understanding of the evolution and functions of EJC core genes in plants.
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Affiliation(s)
- Pichang Gong
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Jing Li
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chaoying He
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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13
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de Bossoreille S, Morel P, Trehin C, Negrutiu I. REBELOTE, a regulator of floral determinacy in Arabidopsis thaliana, interacts with both nucleolar and nucleoplasmic proteins. FEBS Open Bio 2018; 8:1636-1648. [PMID: 30338215 PMCID: PMC6168688 DOI: 10.1002/2211-5463.12504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 07/24/2018] [Accepted: 07/30/2018] [Indexed: 11/10/2022] Open
Abstract
The nucleoplasm and nucleolus are the two main territories of the nucleus. While specific functions are associated with each of these territories (such as mRNA synthesis in the nucleoplasm and ribosomal rRNA synthesis in the nucleolus), some proteins are known to be located in both. Here, we investigated the molecular function of REBELOTE (RBL), an Arabidopsis thaliana protein previously characterized as a regulator of floral meristem termination. We show that RBL displays a dual localization, in the nucleolus and nucleoplasm. Moreover, we used direct and global approaches to demonstrate that RBL interacts with nucleic acid-binding proteins. It binds to the NOC proteins SWA2, AtNOC2 and AtNOC3 in both the nucleolus and nucleoplasm, and also to OBE1 and VFP3/ENAP1. Taking into account the identities of these RBL interactors, we hypothesize that RBL acts both in ribosomal biogenesis and in the regulation of gene expression.
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Affiliation(s)
- Stève de Bossoreille
- Laboratoire Reproduction et Développement des Plantes Univ Lyon ENS de Lyon UCB Lyon 1 CNRS, INRA Lyon France
| | - Patrice Morel
- Laboratoire Reproduction et Développement des Plantes Univ Lyon ENS de Lyon UCB Lyon 1 CNRS, INRA Lyon France
| | - Christophe Trehin
- Laboratoire Reproduction et Développement des Plantes Univ Lyon ENS de Lyon UCB Lyon 1 CNRS, INRA Lyon France
| | - Ioan Negrutiu
- Laboratoire Reproduction et Développement des Plantes Univ Lyon ENS de Lyon UCB Lyon 1 CNRS, INRA Lyon France
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14
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Baroux C, Schubert V. Technical Review: Microscopy and Image Processing Tools to Analyze Plant Chromatin: Practical Considerations. Methods Mol Biol 2018; 1675:537-589. [PMID: 29052212 DOI: 10.1007/978-1-4939-7318-7_31] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
In situ nucleus and chromatin analyses rely on microscopy imaging that benefits from versatile, efficient fluorescent probes and proteins for static or live imaging. Yet the broad choice in imaging instruments offered to the user poses orientation problems. Which imaging instrument should be used for which purpose? What are the main caveats and what are the considerations to best exploit each instrument's ability to obtain informative and high-quality images? How to infer quantitative information on chromatin or nuclear organization from microscopy images? In this review, we present an overview of common, fluorescence-based microscopy systems and discuss recently developed super-resolution microscopy systems, which are able to bridge the resolution gap between common fluorescence microscopy and electron microscopy. We briefly present their basic principles and discuss their possible applications in the field, while providing experience-based recommendations to guide the user toward best-possible imaging. In addition to raw data acquisition methods, we discuss commercial and noncommercial processing tools required for optimal image presentation and signal evaluation in two and three dimensions.
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Affiliation(s)
- Célia Baroux
- Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, 8008, Zürich, Switzerland.
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466, Seeland, Germany
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15
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Wang W, Lin Y, Teng F, Ji D, Xu Y, Chen C, Xie C. Comparative transcriptome analysis between heat-tolerant and sensitive Pyropia haitanensis strains in response to high temperature stress. ALGAL RES 2018. [DOI: 10.1016/j.algal.2017.11.026] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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16
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Kalinina NO, Makarova S, Makhotenko A, Love AJ, Taliansky M. The Multiple Functions of the Nucleolus in Plant Development, Disease and Stress Responses. FRONTIERS IN PLANT SCIENCE 2018; 9:132. [PMID: 29479362 PMCID: PMC5811523 DOI: 10.3389/fpls.2018.00132] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/23/2018] [Indexed: 05/18/2023]
Abstract
The nucleolus is the most conspicuous domain in the eukaryotic cell nucleus, whose main function is ribosomal RNA (rRNA) synthesis and ribosome biogenesis. However, there is growing evidence that the nucleolus is also implicated in many other aspects of cell biology, such as regulation of cell cycle, growth and development, senescence, telomerase activity, gene silencing, responses to biotic and abiotic stresses. In the first part of the review, we briefly assess the traditional roles of the plant nucleolus in rRNA synthesis and ribosome biogenesis as well as possible functions in other RNA regulatory pathways such as splicing, nonsense-mediated mRNA decay and RNA silencing. In the second part of the review we summarize recent progress and discuss already known and new hypothetical roles of the nucleolus in plant growth and development. In addition, this part will highlight studies showing new nucleolar functions involved in responses to pathogen attack and abiotic stress. Cross-talk between the nucleolus and Cajal bodies is also discussed in the context of their association with poly(ADP ribose)polymerase (PARP), which is known to play a crucial role in various physiological processes including growth, development and responses to biotic and abiotic stresses.
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Affiliation(s)
- Natalia O. Kalinina
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia
- Natalia O. Kalinina
| | - Svetlana Makarova
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia
| | - Antonida Makhotenko
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia
| | | | - Michael Taliansky
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia
- The James Hutton Institute, Dundee, United Kingdom
- *Correspondence: Michael Taliansky
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17
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Lee DH, Park SJ, Ahn CS, Pai HS. MRF Family Genes Are Involved in Translation Control, Especially under Energy-Deficient Conditions, and Their Expression and Functions Are Modulated by the TOR Signaling Pathway. THE PLANT CELL 2017; 29:2895-2920. [PMID: 29084871 PMCID: PMC5728134 DOI: 10.1105/tpc.17.00563] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 10/02/2017] [Accepted: 10/27/2017] [Indexed: 05/20/2023]
Abstract
Dynamic control of protein translation in response to the environment is essential for the survival of plant cells. Target of rapamycin (TOR) coordinates protein synthesis with cellular energy/nutrient availability through transcriptional modulation and phosphorylation of the translation machinery. However, mechanisms of TOR-mediated translation control are poorly understood in plants. Here, we report that Arabidopsis thaliana MRF (MA3 DOMAIN-CONTAINING TRANSLATION REGULATORY FACTOR) family genes encode translation regulatory factors under TOR control, and their functions are particularly important in energy-deficient conditions. Four MRF family genes (MRF1-MRF4) are transcriptionally induced by dark and starvation (DS). Silencing of multiple MRFs increases susceptibility to DS and treatment with a TOR inhibitor, while MRF1 overexpression decreases susceptibility. MRF proteins interact with eIF4A and cofractionate with ribosomes. MRF silencing decreases translation activity, while MRF1 overexpression increases it, accompanied by altered ribosome patterns, particularly in DS. Furthermore, MRF deficiency in DS causes altered distribution of mRNAs in sucrose gradient fractions and accelerates rRNA degradation. MRF1 is phosphorylated in vivo and phosphorylated by S6 kinases in vitro. MRF expression and MRF1 ribosome association and phosphorylation are modulated by cellular energy status and TOR activity. We discuss possible mechanisms of the function of MRF family proteins under normal and energy-deficient conditions and their functional link with the TOR pathway.
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Affiliation(s)
- Du-Hwa Lee
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Seung Jun Park
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Chang Sook Ahn
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Hyun-Sook Pai
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
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18
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The exon junction complex senses energetic stress and regulates contractility and cell architecture in cardiac myocytes. Biosci Rep 2017; 37:BSR20170707. [PMID: 28566540 PMCID: PMC6434082 DOI: 10.1042/bsr20170707] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 05/30/2017] [Accepted: 05/31/2017] [Indexed: 11/17/2022] Open
Abstract
The exon junction complex (EJC) is the main mechanism by which cells select specific mRNAs for translation into protein. We hypothesized that the EJC is involved in the regulation of gene expression during the stress response in cardiac myocytes, with implications for the failing heart. In cultured rat neonatal myocytes, we examined the cellular distribution of two EJC components eukaryotic translation initiation factor 4A isoform 3 (eIF4A3) and mago nashi homologue (Mago) in response to metabolic stress. There was significant relocalization of eIF4A3 and Mago from the nucleus to cytoplasm following 18 h of hypoxia. Treating myocytes with 50 mM NaN3 for 4 h to mimic the metabolic stress induced by hypoxia also resulted in significant relocalization of eIF4A3 and Mago to the cytoplasm. To examine whether the effects of metabolic stress on the EJC proteins were dependent on the metabolic sensor AMP kinase (AMPK), we treated myocytes with 1 μM dorsomorphin (DM) in combination with NaN3 DM augmented the translocation of Mago and eIF4A3 from the nucleus to the cytoplasm. Knockdown of eIF4A3 resulted in cessation of cell contractility 96 h post-treatment and a significant reduction in the number of intact sarcomeres. Cell area was significantly reduced by both hypoxia and eIF4A3 knockdown, whilst eIF4A3 knockdown also significantly reduced nuclear size. The reduction in nuclear size is unlikely to be related to apoptosis as it was reversed in combination with hypoxia. These data suggest for the first time that eIF4A3 and potentially other EJC members play an important role in the myocyte stress response, cell contractility and morphology.
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19
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Park HY, Lee KC, Jang YH, Kim SK, Thu MP, Lee JH, Kim JK. The Arabidopsis splicing factors, AtU2AF65, AtU2AF35, and AtSF1 shuttle between nuclei and cytoplasms. PLANT CELL REPORTS 2017; 36:1113-1123. [PMID: 28432478 DOI: 10.1007/s00299-017-2142-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/12/2017] [Indexed: 05/07/2023]
Abstract
The Arabidopsis splicing factors, AtU2AF65, AtU2AF35, and AtSF1 shuttle between nuclei and cytoplasms. These proteins also move rapidly and continuously in the nuclei, and their movements are affected by ATP depletion. The U2AF65 proteins are splicing factors that interact with SF1 and U2AF35 proteins to promote U2snRNP for the recognition of the pre-mRNA 3' splice site during early spliceosome assembly. We have determined the subcellular localization and movement of these proteins' Arabidopsis homologs. It was found that Arabidopsis U2AF65 homologs, AtU2AF65a, and AtU2AF65b proteins interact with AtU2AF35a and AtU2AF35b, which are Arabidopsis U2AF35 homologs. We have examined the mobility of these proteins including AtSF1 using fluorescence recovery after photobleaching and fluorescence loss in photobleaching analyses. These proteins displayed dynamic movements in nuclei and their movements were affected by ATP depletion. We have also demonstrated that these proteins shuttle between nuclei and cytoplasms, suggesting that they may also function in cytoplasm. These results indicate that such splicing factors show very similar characteristics to their human counterparts, suggesting evolutionary conservation.
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Affiliation(s)
- Hyo-Young Park
- Department of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Keh Chien Lee
- Department of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Yun Hee Jang
- Department of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Soon-Kap Kim
- Division of Biological and Environmental Sciences and Engineering, Center for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - May Phyo Thu
- Department of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Jeong Hwan Lee
- Department of Life Sciences, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-Si, Jeollabuk-do, 54896, Republic of Korea.
| | - Jeong-Kook Kim
- Department of Life Sciences, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul, 02841, Republic of Korea.
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20
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Abstract
The eukaryotic nucleus is enclosed by the nuclear envelope, which is perforated by the nuclear pores, the gateways of macromolecular exchange between the nucleoplasm and cytoplasm. The nucleoplasm is organized in a complex three-dimensional fashion that changes over time and in response to stimuli. Within the cell, the nucleus must be viewed as an organelle (albeit a gigantic one) that is a recipient of cytoplasmic forces and capable of morphological and positional dynamics. The most dramatic reorganization of this organelle occurs during mitosis and meiosis. Although many of these aspects are less well understood for the nuclei of plants than for those of animals or fungi, several recent discoveries have begun to place our understanding of plant nuclei firmly into this broader cell-biological context.
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Affiliation(s)
- Iris Meier
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210;
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom;
| | | | - David E Evans
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom;
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21
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Ohtani M. Plant snRNP Biogenesis: A Perspective from the Nucleolus and Cajal Bodies. FRONTIERS IN PLANT SCIENCE 2017; 8:2184. [PMID: 29354141 PMCID: PMC5758608 DOI: 10.3389/fpls.2017.02184] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 12/12/2017] [Indexed: 05/20/2023]
Abstract
Small nuclear ribonucleoproteins (snRNPs) are protein-RNA complexes composed of specific snRNP-associated proteins along with small nuclear RNAs (snRNAs), which are non-coding RNA molecules abundant in the nucleus. snRNPs mainly function as core components of the spliceosome, the molecular machinery for pre-mRNA splicing. Thus, snRNP biogenesis is a critical issue for plants, essential for the determination of a cell's activity through the regulation of gene expression. The complex process of snRNP biogenesis is initiated by transcription of the snRNA in the nucleus, continues in the cytoplasm, and terminates back in the nucleus. Critical steps of snRNP biogenesis, such as chemical modification of the snRNA and snRNP maturation, occur in the nucleolus and its related sub-nuclear structures, Cajal bodies. In this review, I discuss roles for the nucleolus and Cajal bodies in snRNP biogenesis, and a possible linkage between the regulation of snRNP biogenesis and plant development and environmental responses.
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Affiliation(s)
- Misato Ohtani
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- *Correspondence: Misato Ohtani,
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22
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Mishra BS, Jamsheer K M, Singh D, Sharma M, Laxmi A. Genome-Wide Identification and Expression, Protein-Protein Interaction and Evolutionary Analysis of the Seed Plant-Specific BIG GRAIN and BIG GRAIN LIKE Gene Family. FRONTIERS IN PLANT SCIENCE 2017; 8:1812. [PMID: 29118774 PMCID: PMC5660992 DOI: 10.3389/fpls.2017.01812] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 10/05/2017] [Indexed: 05/10/2023]
Abstract
BIG GRAIN1 (BG1) is an auxin-regulated gene which functions in auxin pathway and positively regulates biomass, grain size and yield in rice. However, the evolutionary origin and divergence of these genes are still unknown. In this study, we found that BG genes are probably originated in seed plants. We also identified that seed plants evolved a class of BIG GRAIN LIKE (BGL) genes which share conserved middle and C-terminal motifs with BG. The BG genes were present in all monocot and eudicot species analyzed; however, the BGL genes were absent in few monocot lineages. Both BG and BGL were found to be serine-rich proteins; however, differences in expansion and rates of retention after whole genome duplication events were observed. Promoters of BG and BGL genes were found to be enriched with auxin-responsive elements and the Arabidopsis thaliana BG and BGL genes were found to be auxin-regulated. The auxin-induced expression of AthBG2 was found to be dependent on the conserved ARF17/19 module. Protein-protein interaction analysis identified that AthBG2 interact with regulators of splicing, transcription and chromatin remodeling. Taken together, this study provides interesting insights about BG and BGL genes and incentivizes future work in this gene family which has the potential to be used for crop manipulation.
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23
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Bush MS, Pierrat O, Nibau C, Mikitova V, Zheng T, Corke FMK, Vlachonasios K, Mayberry LK, Browning KS, Doonan JH. eIF4A RNA Helicase Associates with Cyclin-Dependent Protein Kinase A in Proliferating Cells and Is Modulated by Phosphorylation. PLANT PHYSIOLOGY 2016; 172:128-40. [PMID: 27388680 PMCID: PMC5074640 DOI: 10.1104/pp.16.00435] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/05/2016] [Indexed: 05/03/2023]
Abstract
Eukaryotic initiation factor 4A (eIF4A) is a highly conserved RNA-stimulated ATPase and helicase involved in the initiation of messenger RNA translation. Previously, we found that eIF4A interacts with cyclin-dependent kinase A (CDKA), the plant ortholog of mammalian CDK1. Here, we show that this interaction occurs only in proliferating cells where the two proteins coassociate with 5'-cap-binding protein complexes, eIF4F or the plant-specific eIFiso4F. CDKA phosphorylates eIF4A on a conserved threonine residue (threonine-164) within the RNA-binding motif 1b TPGR. In vivo, a phospho-null (APGR) variant of the Arabidopsis (Arabidopsis thaliana) eIF4A1 protein retains the ability to functionally complement a mutant (eif4a1) plant line lacking eIF4A1, whereas a phosphomimetic (EPGR) variant fails to complement. The phospho-null variant (APGR) rescues the slow growth rate of roots and rosettes, together with the ovule-abortion and late-flowering phenotypes. In vitro, wild-type recombinant eIF4A1 and its phospho-null variant both support translation in cell-free wheat germ extracts dependent upon eIF4A, but the phosphomimetic variant does not support translation and also was deficient in ATP hydrolysis and helicase activity. These observations suggest a mechanism whereby CDK phosphorylation has the potential to down-regulate eIF4A activity and thereby affect translation.
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Affiliation(s)
- Maxwell S Bush
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
| | - Olivier Pierrat
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
| | - Candida Nibau
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
| | - Veronika Mikitova
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
| | - Tao Zheng
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
| | - Fiona M K Corke
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
| | - Konstantinos Vlachonasios
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
| | - Laura K Mayberry
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
| | - Karen S Browning
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
| | - John H Doonan
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom (M.S.B., O.P., V.M.);Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth SY23 3EE, United Kingdom (C.N., F.M.K.C., K.V., J.H.D.);Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou City, Zhejiang Province 310021, China (T.Z.);Aristotle University of Thessaloniki, Faculty of Science, School of Biology, Department of Botany, 54124 Thessaloniki, Greece (K.V.); andDepartment of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas, Austin, Texas 78712 (L.K.M., K.S.B.)
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24
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Moore M, Gossmann N, Dietz KJ. Redox Regulation of Cytosolic Translation in Plants. TRENDS IN PLANT SCIENCE 2016; 21:388-397. [PMID: 26706442 DOI: 10.1016/j.tplants.2015.11.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 10/31/2015] [Accepted: 11/05/2015] [Indexed: 05/19/2023]
Abstract
Control of protein homeostasis is crucial for environmental acclimation of plants. In this context, translational control is receiving increasing attention, particularly since post-translational modifications of the translational apparatus allow very fast and highly effective control of protein synthesis. Reduction and oxidation (redox) reactions decisively control translation by modifying initiation, elongation, and termination of translation. This opinion article compiles information on the redox sensitivity of cytosolic translation factors and the significance of redox regulation as a key modulator of translation for efficient acclimation to changing environmental conditions.
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Affiliation(s)
- Marten Moore
- Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany
| | - Nikolaj Gossmann
- Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany
| | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany.
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25
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Pascuan C, Frare R, Alleva K, Ayub ND, Soto G. mRNA biogenesis-related helicase eIF4AIII from Arabidopsis thaliana is an important factor for abiotic stress adaptation. PLANT CELL REPORTS 2016; 35:1205-1208. [PMID: 26883227 DOI: 10.1007/s00299-016-1947-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 02/02/2016] [Indexed: 06/05/2023]
Abstract
Similar to other plant species, Arabidopsis has a huge repertoire of predicted helicases, including the eIF4AIII factor, a putative component of the exon junction complex related to mRNA biogenesis. In this article, we integrated evolutionary and functional approaches to have a better understanding of eIF4AIII function in plants. Phylogenetic analysis showed that the mRNA biogenesis-related helicase eIF4AIII is the ortholog of the stress-related helicases PDH45 from Pisum sativum and MH1 from Medicago sativa, suggesting evolutionary and probably functional equivalences between mRNA biogenesis and stress-related plant helicases. Molecular and genetic analyses confirmed the relevance of eIF4AIII during abiotic stress adaptation in Arabidopsis. Therefore, in addition to its function in mRNA biogenesis, eIF4AIII can play a role in abiotic stress adaptation.
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Affiliation(s)
- Cecilia Pascuan
- CONICET, Avda. Rivadavia 1917, C1033AAJ CABA, Buenos Aires, Argentina
- IGEAF- INTA, De los reseros S/N, Castelar C25 (1712), Buenos Aires, Argentina
| | - Romina Frare
- CONICET, Avda. Rivadavia 1917, C1033AAJ CABA, Buenos Aires, Argentina
| | - Karina Alleva
- CONICET, Avda. Rivadavia 1917, C1033AAJ CABA, Buenos Aires, Argentina
| | - Nicolás Daniel Ayub
- CONICET, Avda. Rivadavia 1917, C1033AAJ CABA, Buenos Aires, Argentina
- IGEAF- INTA, De los reseros S/N, Castelar C25 (1712), Buenos Aires, Argentina
| | - Gabriela Soto
- CONICET, Avda. Rivadavia 1917, C1033AAJ CABA, Buenos Aires, Argentina.
- IGEAF- INTA, De los reseros S/N, Castelar C25 (1712), Buenos Aires, Argentina.
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26
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Huang CK, Sie YS, Chen YF, Huang TS, Lu CA. Two highly similar DEAD box proteins, OsRH2 and OsRH34, homologous to eukaryotic initiation factor 4AIII, play roles of the exon junction complex in regulating growth and development in rice. BMC PLANT BIOLOGY 2016; 16:84. [PMID: 27071313 PMCID: PMC4830029 DOI: 10.1186/s12870-016-0769-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/06/2016] [Indexed: 05/10/2023]
Abstract
BACKGROUND The exon junction complex (EJC), which contains four core components, eukaryotic initiation factor 4AIII (eIF4AIII), MAGO/NASHI (MAGO), Y14/Tsunagi/RNA-binding protein 8A, and Barentsz/Metastatic lymph node 51, is formed in both nucleus and cytoplasm, and plays important roles in gene expression. Genes encoding core EJC components have been found in plants, including rice. Currently, the functional characterizations of MAGO and Y14 homologs have been demonstrated in rice. However, it is still unknown whether eIF4AIII is essential for the functional EJC in rice. RESULTS This study investigated two DEAD box RNA helicases, OsRH2 and OsRH34, which are homologous to eIF4AIII, in rice. Amino acid sequence analysis indicated that OsRH2 and OsRH34 had 99 % identity and 100 % similarity, and their gene expression patterns were similar in various rice tissues, but the level of OsRH2 mRNA was about 58-fold higher than that of OsRH34 mRNA in seedlings. From bimolecular fluorescence complementation results, OsRH2 and OsRH34 interacted physically with OsMAGO1 and OsY14b, respectively, which indicated that both of OsRH2 and OsRH34 were core components of the EJC in rice. To study the biological roles of OsRH2 and OsRH34 in rice, transgenic rice plants were generated by RNA interference. The phenotypes of three independent OsRH2 and OsRH34 double-knockdown transgenic lines included dwarfism, a short internode distance, reproductive delay, defective embryonic development, and a low seed setting rate. These phenotypes resembled those of mutants with gibberellin-related developmental defects. In addition, the OsRH2 and OsRH34 double-knockdown transgenic lines exhibited the accumulation of unspliced rice UNDEVELOPED TAPETUM 1 mRNA. CONCLUSIONS Rice contains two eIF4AIII paralogous genes, OsRH2 and OsRH34. The abundance of OsRH2 mRNA was about 58-fold higher than that of OsRH34 mRNA in seedlings, suggesting that the OsRH2 is major eIF4AIII in rice. Both OsRH2 and OsRH34 are core components of the EJC, and participate in regulating of plant height, pollen, and seed development in rice.
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Affiliation(s)
- Chun-Kai Huang
- Department of Life Sciences, National Central University, Jhongli District, Taoyuan City 32001 Taiwan (ROC)
| | - Yi-Syuan Sie
- Department of Life Sciences, National Central University, Jhongli District, Taoyuan City 32001 Taiwan (ROC)
| | - Yu-Fu Chen
- Department of Life Sciences, National Central University, Jhongli District, Taoyuan City 32001 Taiwan (ROC)
| | - Tian-Sheng Huang
- Department of Life Sciences, National Central University, Jhongli District, Taoyuan City 32001 Taiwan (ROC)
| | - Chung-An Lu
- Department of Life Sciences, National Central University, Jhongli District, Taoyuan City 32001 Taiwan (ROC)
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27
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Palm D, Simm S, Darm K, Weis BL, Ruprecht M, Schleiff E, Scharf C. Proteome distribution between nucleoplasm and nucleolus and its relation to ribosome biogenesis in Arabidopsis thaliana. RNA Biol 2016; 13:441-54. [PMID: 26980300 DOI: 10.1080/15476286.2016.1154252] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Ribosome biogenesis is an essential process initiated in the nucleolus. In eukaryotes, multiple ribosome biogenesis factors (RBFs) can be found in the nucleolus, the nucleus and in the cytoplasm. They act in processing, folding and modification of the pre-ribosomal (r)RNAs, incorporation of ribosomal proteins (RPs), export of pre-ribosomal particles to the cytoplasm, and quality control mechanisms. Ribosome biogenesis is best established for Saccharomyces cerevisiae. Plant ortholog assignment to yeast RBFs revealed the absence of about 30% of the yeast RBFs in plants. In turn, few plant specific proteins have been identified by biochemical experiments to act in plant ribosome biogenesis. Nevertheless, a complete inventory of plant RBFs has not been established yet. We analyzed the proteome of the nucleus and nucleolus of Arabidopsis thaliana and the post-translational modifications of these proteins. We identified 1602 proteins in the nucleolar and 2544 proteins in the nuclear fraction with an overlap of 1429 proteins. For a randomly selected set of proteins identified by the proteomic approach we confirmed the localization inferred from the proteomics data by the localization of GFP fusion proteins. We assigned the identified proteins to various complexes and functions and found about 519 plant proteins that have a potential to act as a RBFs, but which have not been experimentally characterized yet. Last, we compared the distribution of RBFs and RPs in the various fractions with the distribution established for yeast.
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Affiliation(s)
| | - Stefan Simm
- a Institute for Molecular Biosciences.,b Cluster of Excellence Macromolecular Complexes
| | - Katrin Darm
- d Department of Otorhinolaryngology , Head and Neck Surgery
| | | | | | - Enrico Schleiff
- a Institute for Molecular Biosciences.,b Cluster of Excellence Macromolecular Complexes.,c Buchman Institute for Molecular Life Sciences, Goethe University Frankfurt , Max von Laue Str. Nine, Frankfurt , Germany
| | - Christian Scharf
- d Department of Otorhinolaryngology , Head and Neck Surgery.,e Interfaculty Institute of Genetics and Functional Genomics, University Medicine Greifswald , Ferdinand-Sauerbruch-Straße DZ7 J.05.06, Greifswald , Germany
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28
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Cui P, Chen T, Qin T, Ding F, Wang Z, Chen H, Xiong L. The RNA Polymerase II C-Terminal Domain Phosphatase-Like Protein FIERY2/CPL1 Interacts with eIF4AIII and Is Essential for Nonsense-Mediated mRNA Decay in Arabidopsis. THE PLANT CELL 2016; 28:770-85. [PMID: 26887918 PMCID: PMC4826008 DOI: 10.1105/tpc.15.00771] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 02/04/2016] [Accepted: 02/15/2016] [Indexed: 05/18/2023]
Abstract
Nonsense-mediated decay (NMD) is a posttranscriptional surveillance mechanism in eukaryotes that recognizes and degrades transcripts with premature translation-termination codons. The RNA polymerase II C-terminal domain phosphatase-like protein FIERY2 (FRY2; also known as C-TERMINAL DOMAIN PHOSPHATASE-LIKE1 [CPL1]) plays multiple roles in RNA processing in Arabidopsis thaliana Here, we found that FRY2/CPL1 interacts with two NMD factors, eIF4AIII and UPF3, and is involved in the dephosphorylation of eIF4AIII. This dephosphorylation retains eIF4AIII in the nucleus and limits its accumulation in the cytoplasm. By analyzing RNA-seq data combined with quantitative RT-PCR validation, we found that a subset of alternatively spliced transcripts and 5'-extended mRNAs with NMD-eliciting features accumulated in the fry2-1 mutant, cycloheximide-treated wild type, and upf3 mutant plants, indicating that FRY2 is essential for the degradation of these NMD transcripts.
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Affiliation(s)
- Peng Cui
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Tao Chen
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Tao Qin
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Feng Ding
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Zhenyu Wang
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Hao Chen
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Liming Xiong
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
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29
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Cilano K, Mazanek Z, Khan M, Metcalfe S, Zhang XN. A New Mutation, hap1-2, Reveals a C Terminal Domain Function in AtMago Protein and Its Biological Effects in Male Gametophyte Development in Arabidopsis thaliana. PLoS One 2016; 11:e0148200. [PMID: 26867216 PMCID: PMC4750992 DOI: 10.1371/journal.pone.0148200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Accepted: 01/14/2016] [Indexed: 01/02/2023] Open
Abstract
The exon-exon junction complex (EJC) is a conserved eukaryotic multiprotein complex that examines the quality of and determines the availability of messenger RNAs (mRNAs) posttranscriptionally. Four proteins, MAGO, Y14, eIF4AIII and BTZ, function as core components of the EJC. The mechanisms of their interactions and the biological indications of these interactions are still poorly understood in plants. A new mutation, hap1-2. leads to premature pollen death and a reduced seed production in Arabidopsis. This mutation introduces a viable truncated transcript AtMagoΔC. This truncation abolishes the interaction between AtMago and AtY14 in vitro, but not the interaction between AtMago and AteIF4AIII. In addition to a strong nuclear presence of AtMago, both AtMago and AtMagoΔC exhibit processing-body (P-body) localization. This indicates that AtMagoΔC may replace AtMago in the EJC when aberrant transcripts are to be degraded. When introducing an NMD mutation, upf3-1, into the existing HAP1/hap1-2 mutant, plants showed a severely reduced fertility. However, the change of splicing pattern of a subset of SR protein transcripts is mostly correlated with the sr45-1 and upf3-1 mutations, not the hap1-2 mutation. These results imply that the C terminal domain (CTD) of AtMago is required for the AtMago-AtY14 heterodimerization during EJC assembly, UPF3-mediated NMD pathway and the AtMago-AtY14 heterodimerization work synergistically to regulate male gametophyte development in plants.
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MESH Headings
- Amino Acid Sequence
- Animals
- Arabidopsis/genetics
- Arabidopsis/physiology
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/physiology
- Base Sequence
- Cloning, Molecular
- Crosses, Genetic
- DNA Primers/genetics
- DNA, Complementary/metabolism
- Dimerization
- Exons
- Genes, Plant
- Germ Cells, Plant
- Humans
- Microscopy, Confocal
- Molecular Sequence Data
- Mutation
- Nuclear Proteins/genetics
- Nuclear Proteins/physiology
- Plants, Genetically Modified
- Pollen/physiology
- Protein Structure, Secondary
- Protein Structure, Tertiary
- RNA Processing, Post-Transcriptional
- RNA Splicing
- RNA Stability
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA-Binding Proteins/metabolism
- Seeds/metabolism
- Sequence Alignment
- Sequence Homology, Amino Acid
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Affiliation(s)
- Kevin Cilano
- Department of Biology, Saint Bonaventure University, Saint Bonaventure, New York, United States of America
| | - Zachary Mazanek
- Biochemistry Program, Saint Bonaventure University, Saint Bonaventure, New York, United States of America
| | - Mahmuda Khan
- Department of Biology, Saint Bonaventure University, Saint Bonaventure, New York, United States of America
| | - Sarah Metcalfe
- Biochemistry Program, Saint Bonaventure University, Saint Bonaventure, New York, United States of America
| | - Xiao-Ning Zhang
- Department of Biology, Saint Bonaventure University, Saint Bonaventure, New York, United States of America
- Biochemistry Program, Saint Bonaventure University, Saint Bonaventure, New York, United States of America
- * E-mail:
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30
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Lokdarshi A, Conner WC, McClintock C, Li T, Roberts DM. Arabidopsis CML38, a Calcium Sensor That Localizes to Ribonucleoprotein Complexes under Hypoxia Stress. PLANT PHYSIOLOGY 2016; 170:1046-59. [PMID: 26634999 PMCID: PMC4734562 DOI: 10.1104/pp.15.01407] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/30/2015] [Indexed: 05/18/2023]
Abstract
During waterlogging and the associated oxygen deprivation stress, plants respond by the induction of adaptive programs, including the redirected expression of gene networks toward the synthesis of core hypoxia-response proteins. Among these core response proteins in Arabidopsis (Arabidopsis thaliana) is the calcium sensor CML38, a protein related to regulator of gene silencing calmodulin-like proteins (rgsCaMs). CML38 transcripts are up-regulated more than 300-fold in roots within 6 h of hypoxia treatment. Transfer DNA insertional mutants of CML38 show an enhanced sensitivity to hypoxia stress, with lowered survival and more severe inhibition of root and shoot growth. By using yellow fluorescent protein (YFP) translational fusions, CML38 protein was found to be localized to cytosolic granule structures similar in morphology to hypoxia-induced stress granules. Immunoprecipitation of CML38 from the roots of hypoxia-challenged transgenic plants harboring CML38pro::CML38:YFP followed by liquid chromatography-tandem mass spectrometry analysis revealed the presence of protein targets associated with messenger RNA ribonucleoprotein (mRNP) complexes including stress granules, which are known to accumulate as messenger RNA storage and triage centers during hypoxia. This finding is further supported by the colocalization of CML38 with the mRNP stress granule marker RNA Binding Protein 47 (RBP47) upon cotransfection of Nicotiana benthamiana leaves. Ruthenium Red treatment results in the loss of CML38 signal in cytosolic granules, suggesting that calcium is necessary for stress granule association. These results confirm that CML38 is a core hypoxia response calcium sensor protein and suggest that it serves as a potential calcium signaling target within stress granules and other mRNPs that accumulate during flooding stress responses.
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Affiliation(s)
- Ansul Lokdarshi
- Department of Biochemistry and Cellular and Molecular Biology (A.L., W.C.C., C.M., D.M.R.) and Program in Genome Science and Technology (T.L., D.M.R.), University of Tennessee, Knoxville, Tennessee 37996
| | - W Craig Conner
- Department of Biochemistry and Cellular and Molecular Biology (A.L., W.C.C., C.M., D.M.R.) and Program in Genome Science and Technology (T.L., D.M.R.), University of Tennessee, Knoxville, Tennessee 37996
| | - Carlee McClintock
- Department of Biochemistry and Cellular and Molecular Biology (A.L., W.C.C., C.M., D.M.R.) and Program in Genome Science and Technology (T.L., D.M.R.), University of Tennessee, Knoxville, Tennessee 37996
| | - Tian Li
- Department of Biochemistry and Cellular and Molecular Biology (A.L., W.C.C., C.M., D.M.R.) and Program in Genome Science and Technology (T.L., D.M.R.), University of Tennessee, Knoxville, Tennessee 37996
| | - Daniel M Roberts
- Department of Biochemistry and Cellular and Molecular Biology (A.L., W.C.C., C.M., D.M.R.) and Program in Genome Science and Technology (T.L., D.M.R.), University of Tennessee, Knoxville, Tennessee 37996
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31
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Xing D, Wang Y, Hamilton M, Ben-Hur A, Reddy ASN. Transcriptome-Wide Identification of RNA Targets of Arabidopsis SERINE/ARGININE-RICH45 Uncovers the Unexpected Roles of This RNA Binding Protein in RNA Processing. THE PLANT CELL 2015; 27:3294-308. [PMID: 26603559 PMCID: PMC4707455 DOI: 10.1105/tpc.15.00641] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/19/2015] [Accepted: 11/03/2015] [Indexed: 05/20/2023]
Abstract
Plant SR45 and its metazoan ortholog RNPS1 are serine/arginine-rich (SR)-like RNA binding proteins that function in splicing/postsplicing events and regulate diverse processes in eukaryotes. Interactions of SR45 with both RNAs and proteins are crucial for regulating RNA processing. However, in vivo RNA targets of SR45 are currently unclear. Using RNA immunoprecipitation followed by high-throughput sequencing, we identified over 4000 Arabidopsis thaliana RNAs that directly or indirectly associate with SR45, designated as SR45-associated RNAs (SARs). Comprehensive analyses of these SARs revealed several roles for SR45. First, SR45 associates with and regulates the expression of 30% of abscisic acid (ABA) signaling genes at the postsplicing level. Second, although most SARs are derived from intron-containing genes, surprisingly, 340 SARs are derived from intronless genes. Expression analysis of the SARs suggests that SR45 differentially regulates intronless and intron-containing SARs. Finally, we identified four overrepresented RNA motifs in SARs that likely mediate SR45's recognition of its targets. Therefore, SR45 plays an unexpected role in mRNA processing of intronless genes, and numerous ABA signaling genes are targeted for regulation at the posttranscriptional level. The diverse molecular functions of SR45 uncovered in this study are likely applicable to other species in view of its conservation across eukaryotes.
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Affiliation(s)
- Denghui Xing
- Department of Biology and Program in Molecular Plant Biology, Colorado State University, Fort Collins, Colorado 80523
| | - Yajun Wang
- Department of Biology and Program in Molecular Plant Biology, Colorado State University, Fort Collins, Colorado 80523
| | - Michael Hamilton
- Computer Science Department, Colorado State University, Fort Collins, Colorado 80523
| | - Asa Ben-Hur
- Computer Science Department, Colorado State University, Fort Collins, Colorado 80523
| | - Anireddy S N Reddy
- Department of Biology and Program in Molecular Plant Biology, Colorado State University, Fort Collins, Colorado 80523
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32
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Bush MS, Crowe N, Zheng T, Doonan JH. The RNA helicase, eIF4A-1, is required for ovule development and cell size homeostasis in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:989-1004. [PMID: 26493293 PMCID: PMC4737287 DOI: 10.1111/tpj.13062] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/09/2015] [Accepted: 10/15/2015] [Indexed: 05/19/2023]
Abstract
eIF4A is a highly conserved RNA-stimulated ATPase and helicase involved in the initiation of mRNA translation. The Arabidopsis genome encodes two isoforms, one of which (eIF4A-1) is required for the coordination between cell cycle progression and cell size. A T-DNA mutant eif4a1 line, with reduced eIF4A protein levels, displays slow growth, reduced lateral root formation, delayed flowering and abnormal ovule development. Loss of eIF4A-1 reduces the proportion of mitotic cells in the root meristem and perturbs the relationship between cell size and cell cycle progression. Several cell cycle reporter proteins, particularly those expressed at G2/M, have reduced expression in eif4a1 mutant meristems. Single eif4a1 mutants are semisterile and show aberrant ovule growth, whereas double eif4a1 eif4a2 homozygous mutants could not be recovered, indicating that eIF4A function is essential for plant growth and development.
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Affiliation(s)
- Maxwell S Bush
- Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, Norwich, NR4 7UH, UK
| | - Natalie Crowe
- Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, Norwich, NR4 7UH, UK
| | - Tao Zheng
- Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, Norwich, NR4 7UH, UK
| | - John H Doonan
- Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, Norwich, NR4 7UH, UK
- Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Gogerddan Campus, Aberystwyth, SY23 3EE, UK
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Choudhry H, Albukhari A, Morotti M, Haider S, Moralli D, Smythies J, Schödel J, Green CM, Camps C, Buffa F, Ratcliffe P, Ragoussis J, Harris AL, Mole DR. Tumor hypoxia induces nuclear paraspeckle formation through HIF-2α dependent transcriptional activation of NEAT1 leading to cancer cell survival. Oncogene 2015; 34:4482-90. [PMID: 25417700 PMCID: PMC4430310 DOI: 10.1038/onc.2014.378] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/29/2014] [Accepted: 10/10/2014] [Indexed: 12/18/2022]
Abstract
Activation of cellular transcriptional responses, mediated by hypoxia-inducible factor (HIF), is common in many types of cancer, and generally confers a poor prognosis. Known to induce many hundreds of protein-coding genes, HIF has also recently been shown to be a key regulator of the non-coding transcriptional response. Here, we show that NEAT1 long non-coding RNA (lncRNA) is a direct transcriptional target of HIF in many breast cancer cell lines and in solid tumors. Unlike previously described lncRNAs, NEAT1 is regulated principally by HIF-2 rather than by HIF-1. NEAT1 is a nuclear lncRNA that is an essential structural component of paraspeckles and the hypoxic induction of NEAT1 induces paraspeckle formation in a manner that is dependent upon both NEAT1 and on HIF-2. Paraspeckles are multifunction nuclear structures that sequester transcriptionally active proteins as well as RNA transcripts that have been subjected to adenosine-to-inosine (A-to-I) editing. We show that the nuclear retention of one such transcript, F11R (also known as junctional adhesion molecule 1, JAM1), in hypoxia is dependent upon the hypoxic increase in NEAT1, thereby conferring a novel mechanism of HIF-dependent gene regulation. Induction of NEAT1 in hypoxia also leads to accelerated cellular proliferation, improved clonogenic survival and reduced apoptosis, all of which are hallmarks of increased tumorigenesis. Furthermore, in patients with breast cancer, high tumor NEAT1 expression correlates with poor survival. Taken together, these results indicate a new role for HIF transcriptional pathways in the regulation of nuclear structure and that this contributes to the pro-tumorigenic hypoxia-phenotype in breast cancer.
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Affiliation(s)
- H Choudhry
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Headington, Oxford, UK
| | - A Albukhari
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Weatherall Institute of Molecular Medicine, Department of Oncology, University of Oxford, Oxford, UK
| | - M Morotti
- Weatherall Institute of Molecular Medicine, Department of Oncology, University of Oxford, Oxford, UK
| | - S Haider
- Weatherall Institute of Molecular Medicine, Department of Oncology, University of Oxford, Oxford, UK
| | - D Moralli
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Headington, Oxford, UK
| | - J Smythies
- The Henry Wellcome Building for Molecular Physiology, University of Oxford, Headington, Oxford, UK
| | - J Schödel
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - C M Green
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Headington, Oxford, UK
| | - C Camps
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Headington, Oxford, UK
| | - F Buffa
- Old Road Campus Research Building, University of Oxford, Headington, Oxford, UK
| | - P Ratcliffe
- The Henry Wellcome Building for Molecular Physiology, University of Oxford, Headington, Oxford, UK
| | - J Ragoussis
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Headington, Oxford, UK
- McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada
- BSRC Alexander Fleming, Athens, Greece
| | - A L Harris
- Weatherall Institute of Molecular Medicine, Department of Oncology, University of Oxford, Oxford, UK
| | - D R Mole
- The Henry Wellcome Building for Molecular Physiology, University of Oxford, Headington, Oxford, UK
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Chen T, Cui P, Xiong L. The RNA-binding protein HOS5 and serine/arginine-rich proteins RS40 and RS41 participate in miRNA biogenesis in Arabidopsis. Nucleic Acids Res 2015; 43:8283-98. [PMID: 26227967 PMCID: PMC4787832 DOI: 10.1093/nar/gkv751] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 07/11/2015] [Indexed: 12/28/2022] Open
Abstract
MicroRNAs are a class of small regulatory RNAs that are generated from primary miRNA (pri-miRNA) transcripts with a stem-loop structure. Accuracy of the processing of pri-miRNA into mature miRNA in plants can be enhanced by SERRATE (SE) and HYPONASTIC LEAVES 1 (HYL1). HYL1 activity is regulated by the FIERY2 (FRY2)/RNA polymerase II C-terminal domain phosphatase-like 1 (CPL1). Here, we discover that HIGH OSMOTIC STRESS GENE EXPRESSION 5 (HOS5) and two serine/arginine-rich splicing factors RS40 and RS41, previously shown to be involved in pre-mRNA splicing, affect the biogenesis of a subset of miRNA. These proteins are required for correct miRNA strand selection and the maintenance of miRNA levels. FRY2 dephosphorylates HOS5 whose phosphorylation status affects its subnuclear localization. HOS5 and the RS proteins bind both intronless and intron-containing pri-miRNAs. Importantly, all of these splicing-related factors directly interact with both HYL1 and SE in nuclear splicing speckles. Our results indicate that these splicing factors are directly involved in the biogenesis of a group of miRNA.
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Affiliation(s)
- Tao Chen
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Peng Cui
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Liming Xiong
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
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Browning KS, Bailey-Serres J. Mechanism of cytoplasmic mRNA translation. THE ARABIDOPSIS BOOK 2015; 13:e0176. [PMID: 26019692 PMCID: PMC4441251 DOI: 10.1199/tab.0176] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Protein synthesis is a fundamental process in gene expression that depends upon the abundance and accessibility of the mRNA transcript as well as the activity of many protein and RNA-protein complexes. Here we focus on the intricate mechanics of mRNA translation in the cytoplasm of higher plants. This chapter includes an inventory of the plant translational apparatus and a detailed review of the translational processes of initiation, elongation, and termination. The majority of mechanistic studies of cytoplasmic translation have been carried out in yeast and mammalian systems. The factors and mechanisms of translation are for the most part conserved across eukaryotes; however, some distinctions are known to exist in plants. A comprehensive understanding of the complex translational apparatus and its regulation in plants is warranted, as the modulation of protein production is critical to development, environmental plasticity and biomass yield in diverse ecosystems and agricultural settings.
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Affiliation(s)
- Karen S. Browning
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin, Austin TX 78712-0165
- Both authors contributed equally to this work
| | - Julia Bailey-Serres
- Department of Botany and Plant Sciences and Center for Plant Cell Biology, University of California, Riverside, CA, 92521 USA
- Both authors contributed equally to this work
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Filichkin S, Priest HD, Megraw M, Mockler TC. Alternative splicing in plants: directing traffic at the crossroads of adaptation and environmental stress. CURRENT OPINION IN PLANT BIOLOGY 2015; 24:125-35. [PMID: 25835141 DOI: 10.1016/j.pbi.2015.02.008] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 02/19/2015] [Accepted: 02/20/2015] [Indexed: 05/20/2023]
Abstract
In recent years, high-throughput sequencing-based analysis of plant transcriptomes has suggested that up to ∼60% of plant gene loci encode alternatively spliced mature transcripts. These studies have also revealed that alternative splicing in plants can be regulated by cell type, developmental stage, the environment, and the circadian clock. Alternative splicing is coupled to RNA surveillance and processing mechanisms, including nonsense mediated decay. Recently, non-protein-coding transcripts have also been shown to undergo alternative splicing. These discoveries collectively describe a robust system of post-transcriptional regulatory feedback loops which influence RNA abundance. In this review, we summarize recent studies describing the specific roles alternative splicing and RNA surveillance play in plant adaptation to environmental stresses and the regulation of the circadian clock.
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Affiliation(s)
- Sergei Filichkin
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA.
| | - Henry D Priest
- Division of Biology and Biomedical Sciences, Washington University, Saint Louis, MO 63130, USA; Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
| | - Molly Megraw
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA
| | - Todd C Mockler
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA; Division of Biology and Biomedical Sciences, Washington University, Saint Louis, MO 63130, USA; Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA.
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37
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Filichkin SA, Cumbie JS, Dharmawardhana P, Jaiswal P, Chang JH, Palusa SG, Reddy ASN, Megraw M, Mockler TC. Environmental stresses modulate abundance and timing of alternatively spliced circadian transcripts in Arabidopsis. MOLECULAR PLANT 2015; 8:207-27. [PMID: 25680774 DOI: 10.1016/j.molp.2014.10.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 10/10/2014] [Accepted: 10/20/2014] [Indexed: 05/21/2023]
Abstract
Environmental stresses profoundly altered accumulation of nonsense mRNAs including intron-retaining (IR) transcripts in Arabidopsis. Temporal patterns of stress-induced IR mRNAs were dissected using both oscillating and non-oscillating transcripts. Broad-range thermal cycles triggered a sharp increase in the long IR CCA1 isoforms and altered their phasing to different times of day. Both abiotic and biotic stresses such as drought or Pseudomonas syringae infection induced a similar increase. Thermal stress induced a time delay in accumulation of CCA1 I4Rb transcripts, whereas functional mRNA showed steady oscillations. Our data favor a hypothesis that stress-induced instabilities of the central oscillator can be in part compensated through fluctuations in abundance and out-of-phase oscillations of CCA1 IR transcripts. Taken together, our results support a concept that mRNA abundance can be modulated through altering ratios between functional and nonsense/IR transcripts. SR45 protein specifically bound to the retained CCA1 intron in vitro, suggesting that this splicing factor could be involved in regulation of intron retention. Transcriptomes of nonsense-mediated mRNA decay (NMD)-impaired and heat-stressed plants shared a set of retained introns associated with stress- and defense-inducible transcripts. Constitutive activation of certain stress response networks in an NMD mutant could be linked to disequilibrium between functional and nonsense mRNAs.
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Affiliation(s)
- Sergei A Filichkin
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA.
| | - Jason S Cumbie
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - Palitha Dharmawardhana
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - Pankaj Jaiswal
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA
| | - Jeff H Chang
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA
| | - Saiprasad G Palusa
- Department of Biology and Program in Molecular Plant Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - A S N Reddy
- Department of Biology and Program in Molecular Plant Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Molly Megraw
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA
| | - Todd C Mockler
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA; Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA.
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Calder G, Hindle C, Chan J, Shaw P. An optical imaging chamber for viewing living plant cells and tissues at high resolution for extended periods. PLANT METHODS 2015; 11:22. [PMID: 25806083 PMCID: PMC4371620 DOI: 10.1186/s13007-015-0065-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 03/12/2015] [Indexed: 05/21/2023]
Abstract
BACKGROUND Recent developments in both microscopy and fluorescent protein technologies have made live imaging a powerful tool for the study of plant cells. However, the complications of keeping plant material alive during a long duration experiment while maintaining maximum resolution has limited the use of these methods. RESULTS Here, we describe an imaging chamber designed to overcome these limitations, which is flexible enough to support a range of sizes of plant materials. We were able use confocal microscopy to follow growth and development of plant cells and tissues over several days. The chamber design is based on a perfusion system, so that the addition of drugs and other experimental treatments are also possible. CONCLUSIONS In this article we present a design of imaging chamber that makes it possible to image plant material with high resolution for extended periods of time.
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Affiliation(s)
- Grant Calder
- Department of Cell & Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH UK
| | - Chris Hindle
- Department of Cell & Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH UK
| | - Jordi Chan
- Department of Cell & Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH UK
| | - Peter Shaw
- Department of Cell & Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH UK
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Abstract
Most of the reported dominant disease-resistance genes in plants, R genes, encode NB-LRR immune receptors. Plant genomes carry many NB-LRR type R genes that recognize specific pathogens and induce resistance against them. Thus, this immune system in plants is thought to perform similar functions as the adaptive immune system in animals. In this review, we provide an overview of the resistance mechanisms, evolution, and agricultural applications of R genes against plant viruses. We also introduce recent advances in research into the regulatory mechanisms of R gene expression, focusing on regulation by microRNAs and introns. One of the most intriguing phenomena that occur following R gene-mediated recognition of viruses is programmed cell death around the initial infection site, although its significance in the survival strategies of plants remains to be elucidated. We discuss the possible benefits for plants of inducing such programmed cell death based on our empirical observations and some hypotheses from an ecological point of view.
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40
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Guo B, Chen Y, Li C, Wang T, Wang R, Wang B, Hu S, Du X, Xing H, Song X, Yao Y, Sun Q, Ni Z. Maize (Zea mays L.) seedling leaf nuclear proteome and differentially expressed proteins between a hybrid and its parental lines. Proteomics 2014; 14:1071-87. [PMID: 24677780 DOI: 10.1002/pmic.201300147] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Revised: 01/10/2014] [Accepted: 01/24/2014] [Indexed: 12/27/2022]
Abstract
To better understand the underlying molecular basis of leaf development in maize, a reference map of nuclear proteins in basal region of seedling leaf was established using a combination of 2DE and MALDI-TOF-MS. In total, 441 reproducible protein spots in nuclear proteome of maize leaf basal region were detected with silver staining in a pH range of 3-10, among which 203 spots corresponding to 163 different proteins were identified. As expected, proteins implicated in RNA and protein-associated functions were overrepresented in nuclear proteome. Remarkably, a high percentage (10%) of proteins was identified to be involved in cell division and growth. In addition, comparative nuclear proteomic analysis in leaf basal region of highly heterotic hybrid Mo17/B73 and its parental lines was also performed and 52 of 445 (11.69%) detected protein spots were differentially expressed between the hybrid and its parental lines, among which 16 protein spots displayed nonadditively expressed pattern. These results indicated that hybridization between two parental lines can cause changes in the expression of a variety of nuclear proteins, which may be responsible for the observed leaf size heterosis.
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Affiliation(s)
- Baojian Guo
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Yanhong Chen
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Chuan Li
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Tianya Wang
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Rui Wang
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Bo Wang
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Sha Hu
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Xiaofen Du
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Hongyan Xing
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Xiao Song
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Yingyin Yao
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Qixin Sun
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
| | - Zhongfu Ni
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE); Beijing Key Laboratory of Crop Genetic Improvement; China Agricultural University; Beijing China
- National Plant Gene Research Centre (Beijing); Beijing China
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Khan A, Garbelli A, Grossi S, Florentin A, Batelli G, Acuna T, Zolla G, Kaye Y, Paul LK, Zhu JK, Maga G, Grafi G, Barak S. The Arabidopsis STRESS RESPONSE SUPPRESSOR DEAD-box RNA helicases are nucleolar- and chromocenter-localized proteins that undergo stress-mediated relocalization and are involved in epigenetic gene silencing. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 79:28-43. [PMID: 24724701 DOI: 10.1111/tpj.12533] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 04/03/2014] [Accepted: 04/08/2014] [Indexed: 05/03/2023]
Abstract
DEAD-box RNA helicases are involved in many aspects of RNA metabolism and in diverse biological processes in plants. Arabidopsis thaliana mutants of two DEAD-box RNA helicases, STRESS RESPONSE SUPPRESSOR1 (STRS1) and STRS2 were previously shown to exhibit tolerance to abiotic stresses and up-regulated stress-responsive gene expression. Here, we show that Arabidopsis STRS-overexpressing lines displayed a less tolerant phenotype and reduced expression of stress-induced genes confirming the STRSs as attenuators of Arabidopsis stress responses. GFP-STRS fusion proteins exhibited localization to the nucleolus, nucleoplasm and chromocenters and exhibited relocalization in response to abscisic acid (ABA) treatment and various stresses. This relocalization was reversed when stress treatments were removed. The STRS proteins displayed mis-localization in specific gene-silencing mutants and exhibited RNA-dependent ATPase and RNA-unwinding activities. In particular, STRS2 showed mis-localization in three out of four mutants of the RNA-directed DNA methylation (RdDM) pathway while STRS1 was mis-localized in the hd2c mutant that is defective in histone deacetylase activity. Furthermore, heterochromatic RdDM target loci displayed reduced DNA methylation and increased expression in the strs mutants. Taken together, our findings suggest that the STRS proteins are involved in epigenetic silencing of gene expression to bring about suppression of the Arabidopsis stress response.
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Affiliation(s)
- Asif Khan
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, 84990, Israel
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42
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Sato Y, Ando S, Takahashi H. Role of intron-mediated enhancement on accumulation of an Arabidopsis NB-LRR class R-protein that confers resistance to Cucumber mosaic virus. PLoS One 2014; 9:e99041. [PMID: 24915153 PMCID: PMC4051679 DOI: 10.1371/journal.pone.0099041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Accepted: 05/04/2014] [Indexed: 11/19/2022] Open
Abstract
The accumulation of RCY1 protein, which is encoded by RESISTANCE TO CMV(Y) (RCY1), a CC-NB-LRR class R-gene, is tightly correlated with the strength of the resistance to a yellow strain of Cucumber mosaic virus [CMV(Y)] in Arabidopsis thaliana. In order to enhance resistance to CMV by overexpression of RCY1, A. thaliana was transformed with intron-less RCY1 cDNA construct under the control of strong CaMV35S promoter. Remarkably, a relative amount of RCY1 protein accumulation in the transformants was much lower than that in plants expressing genomic RCY1 under the control of its native promoter. To identify a regulatory element of RCY1 that could cause such differential levels of RCY1 accumulation, a series of RCY1 cDNA and genomic RCY1 constructs were transiently expressed in Nicotiana benthamiana leaves by the Agrobacterium-mediated infiltration method. Comparative analysis of the level of RCY1 accumulation in the leaf tissues transiently expressing each construct indicated that the intron located in the RCY1-coding region of genomic RCY1, but not the native RCY1 genomic promoter or the 5'-and 3'-untranslated regions of RCY1, was indispensable for high level RCY1 accumulation. The increased levels of RCY1 accelerated plant disease defense reactions. Interestingly, such intron-mediated enhancement of RCY1 accumulation depended neither on the abundance of the RCY1 transcript nor on the RCY1 specific-intron sequence. Taken together, intron-mediated RCY1 expression seems to play a key role in the expression of complete resistance to CMV(Y) by maintaining RCY1 accumulation at high levels.
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Affiliation(s)
- Yukiyo Sato
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan
| | - Sugihiro Ando
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan
| | - Hideki Takahashi
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan
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43
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Connecting the dots of RNA-directed DNA methylation in Arabidopsis thaliana. Chromosome Res 2014; 22:225-40. [PMID: 24846724 DOI: 10.1007/s10577-014-9425-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Noncoding RNAs are the rising stars of genome regulation and are crucial to an organism's metabolism, development, and defense. One of their most notable functions is its ability to direct epigenetic modifications through small RNA molecules to specific genomic regions, ensuring transcriptional regulation, proper genome organization, and maintenance of genome integrity. Here, we review the current knowledge of the spatial organization of the Arabidopsis thaliana RNA-directed DNA methylation pathway within the cell nucleus, which, while known to be essential for the proper establishment of epigenetic modifications, remains poorly understood. We will also discuss possible future cytological approaches that have the potential of unveiling functional insights into how small RNA-directed epigenetics is regulated through the spatiotemporal regulation of its major components within the cell.
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44
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Reňák D, Gibalová A, Solcová K, Honys D. A new link between stress response and nucleolar function during pollen development in Arabidopsis mediated by AtREN1 protein. PLANT, CELL & ENVIRONMENT 2014; 37:670-83. [PMID: 23961845 DOI: 10.1111/pce.12186] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Heat shock transcription factors (Hsfs) are involved in multiple aspects of stress response and plant growth. However, their role during male gametophyte development is largely unknown, although the generative phase is the most sensitive and critical period in the plant life cycle. Based on a wide screen of T-DNA mutant lines, we identified the atren1 mutation (restricted to nucleolus1) in early male gametophytic gene At1g77570, which has the closest homology to HSFA5 gene, the member of a heat shock transcription factor (HSF) gene family. The mutation causes multiple defects in male gametophyte development in both structure and function. Because the mutation disrupts an early acting (AtREN1) gene, these pollen phenotype abnormalities appear from bicellular pollen stage to pollen maturation. Moreover, the consequent progamic phase is compromised as well as documented by pollen germination defects and limited transmission via male gametophyte. In addition, atren1/- plants are defective in heat stress (HS) response and produce notably higher proportion of aberrant pollen grains. AtREN1 protein is targeted specifically to the nucleolus that, together with the increased size of the nucleolus in atren1 pollen, suggests that it is likely to be involved in ribosomal RNA biogenesis or other nucleolar functions.
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Affiliation(s)
- David Reňák
- Laboratory of Pollen Biology, Institute of Experimental Botany v.v.i. ASCR, Rozvojová 263, Prague 6, 165 02, Czech Republic
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Barak S, Singh Yadav N, Khan A. DEAD-box RNA helicases and epigenetic control of abiotic stress-responsive gene expression. PLANT SIGNALING & BEHAVIOR 2014; 9:e977729. [PMID: 25517295 PMCID: PMC4622835 DOI: 10.4161/15592324.2014.977729] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Plant responses to abiotic stresses are controlled by a complex tier of epigenetic, transcriptional and post-transcriptional regulation. We have provided evidence that the DEAD-box RNA helicases, STRESS RESPONSE SUPPRESSOR (STRS) 1 and STRS2 are negative regulators of Arabidopsis thaliana stress-responsive transcription factors. Using GFP-STRS fusion proteins, we have demonstrated that the STRSs are localized to the nucleolus and chromocenters, and are rapidly removed to the nucleoplasm upon application of various abiotic stresses. The STRSs appear to act via RNA-directed DNA methylation to suppress Arabidopsis stress responses; this repressive epigenetic mechanism is abrogated by abiotic stress eventually leading to an open chromatin structure allowing expression of stress-responsive genes.
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Affiliation(s)
- Simon Barak
- French Associates Institute for Agriculture and Biotechnology of Drylands; Jacob Blaustein Institutes for Desert Research; Ben-Gurion University of the Negev; Midreshet Ben-Gurion, Israel
- Correspondence to: Simon Barak;
| | - Narendra Singh Yadav
- French Associates Institute for Agriculture and Biotechnology of Drylands; Jacob Blaustein Institutes for Desert Research; Ben-Gurion University of the Negev; Midreshet Ben-Gurion, Israel
| | - Asif Khan
- French Associates Institute for Agriculture and Biotechnology of Drylands; Jacob Blaustein Institutes for Desert Research; Ben-Gurion University of the Negev; Midreshet Ben-Gurion, Israel
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Chen T, Cui P, Chen H, Ali S, Zhang S, Xiong L. A KH-domain RNA-binding protein interacts with FIERY2/CTD phosphatase-like 1 and splicing factors and is important for pre-mRNA splicing in Arabidopsis. PLoS Genet 2013; 9:e1003875. [PMID: 24146632 PMCID: PMC3798263 DOI: 10.1371/journal.pgen.1003875] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 08/28/2013] [Indexed: 11/19/2022] Open
Abstract
Eukaryotic genomes encode hundreds of RNA-binding proteins, yet the functions of most of these proteins are unknown. In a genetic study of stress signal transduction in Arabidopsis, we identified a K homology (KH)-domain RNA-binding protein, HOS5 (High Osmotic Stress Gene Expression 5), as required for stress gene regulation and stress tolerance. HOS5 was found to interact with FIERY2/RNA polymerase II (RNAP II) carboxyl terminal domain (CTD) phosphatase-like 1 (FRY2/CPL1) both in vitro and in vivo. This interaction is mediated by the first double-stranded RNA-binding domain of FRY2/CPL1 and the KH domains of HOS5. Interestingly, both HOS5 and FRY2/CPL1 also interact with two novel serine-arginine (SR)-rich splicing factors, RS40 and RS41, in nuclear speckles. Importantly, FRY2/CPL1 is required for the recruitment of HOS5. In fry2 mutants, HOS5 failed to be localized in nuclear speckles but was found mainly in the nucleoplasm. hos5 mutants were impaired in mRNA export and accumulated a significant amount of mRNA in the nuclei, particularly under salt stress conditions. Arabidopsis mutants of all these genes exhibit similar stress-sensitive phenotypes. RNA-seq analyses of these mutants detected significant intron retention in many stress-related genes under salt stress but not under normal conditions. Our study not only identified several novel regulators of pre-mRNA processing as important for plant stress response but also suggested that, in addition to RNAP II CTD that is a well-recognized platform for the recruitment of mRNA processing factors, FRY2/CPL1 may also recruit specific factors to regulate the co-transcriptional processing of certain transcripts to deal with environmental challenges. Pre-mRNA processing, including 5′ capping, splicing, and 3′ polyadenylation, is critical for gene expression and is closely coupled with transcription. Phosphorylated carboxyl terminal domain (CTD) of RNA Polymerase II (RNAP II) serves as a platform for the recruitment of pre-mRNA processing factors, yet other components involved in the recruitment are less known. In a genetic study of stress signal transduction in Arabidopsis, we isolated a KH-domain RNA-binding protein HOS5 that plays important roles in stress gene regulation and stress tolerance. We found that HOS5 interacts with FIERY2/CTD phosphatase-like 1 (FRY2/CPL1) and they both also interact with two novel splicing factors, RS40 and RS41, in nuclear speckles. In fry2 mutants, HOS5 was unable to be recruited to nuclear speckles but rather was mainly localized in the nucleoplasm. Mutants in these genes have similar stress-sensitive phenotypes. Transcriptome analyses identified significant intron retention in many stress-related genes in these mutants under salt stress conditions. Our study reveals that, in addition to RNAP II, the CTD phosphatase may also recruit specific splicing factors and RNA binding proteins to regulate the co-transcriptional processing of certain transcripts to deal with environmental stresses.
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Affiliation(s)
- Tao Chen
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Peng Cui
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Hao Chen
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Shahjahan Ali
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Shoudong Zhang
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Liming Xiong
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- * E-mail:
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Staiger D, Brown JWS. Alternative splicing at the intersection of biological timing, development, and stress responses. THE PLANT CELL 2013. [PMID: 24179132 DOI: 10.1105/tcp.113.117523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
High-throughput sequencing for transcript profiling in plants has revealed that alternative splicing (AS) affects a much higher proportion of the transcriptome than was previously assumed. AS is involved in most plant processes and is particularly prevalent in plants exposed to environmental stress. The identification of mutations in predicted splicing factors and spliceosomal proteins that affect cell fate, the circadian clock, plant defense, and tolerance/sensitivity to abiotic stress all point to a fundamental role of splicing/AS in plant growth, development, and responses to external cues. Splicing factors affect the AS of multiple downstream target genes, thereby transferring signals to alter gene expression via splicing factor/AS networks. The last two to three years have seen an ever-increasing number of examples of functional AS. At a time when the identification of AS in individual genes and at a global level is exploding, this review aims to bring together such examples to illustrate the extent and importance of AS, which are not always obvious from individual publications. It also aims to ensure that plant scientists are aware that AS is likely to occur in the genes that they study and that dynamic changes in AS and its consequences need to be considered routinely.
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Affiliation(s)
- Dorothee Staiger
- Molecular Cell Physiology, Bielefeld University, D33615 Bielefeld, Germany
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Staiger D, Brown JW. Alternative splicing at the intersection of biological timing, development, and stress responses. THE PLANT CELL 2013; 25:3640-56. [PMID: 24179132 PMCID: PMC3877812 DOI: 10.1105/tpc.113.113803] [Citation(s) in RCA: 425] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 05/15/2013] [Accepted: 10/08/2013] [Indexed: 05/18/2023]
Abstract
High-throughput sequencing for transcript profiling in plants has revealed that alternative splicing (AS) affects a much higher proportion of the transcriptome than was previously assumed. AS is involved in most plant processes and is particularly prevalent in plants exposed to environmental stress. The identification of mutations in predicted splicing factors and spliceosomal proteins that affect cell fate, the circadian clock, plant defense, and tolerance/sensitivity to abiotic stress all point to a fundamental role of splicing/AS in plant growth, development, and responses to external cues. Splicing factors affect the AS of multiple downstream target genes, thereby transferring signals to alter gene expression via splicing factor/AS networks. The last two to three years have seen an ever-increasing number of examples of functional AS. At a time when the identification of AS in individual genes and at a global level is exploding, this review aims to bring together such examples to illustrate the extent and importance of AS, which are not always obvious from individual publications. It also aims to ensure that plant scientists are aware that AS is likely to occur in the genes that they study and that dynamic changes in AS and its consequences need to be considered routinely.
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Affiliation(s)
- Dorothee Staiger
- Molecular Cell Physiology, Bielefeld University, D33615 Bielefeld, Germany
- Institute for Genome Research and Systems Biology, CeBiTec, D33615 Bielefeld, Germany
| | - John W.S. Brown
- Division of Plant Sciences, University of Dundee at The James Hutton Institute, Invergowrie DD2 5DA, Scotland, United Kingdom
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie DD2 5DA, Scotland, United Kingdom
- Address correspondence to
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De Novo Methyltransferase, OsDRM2, Interacts with the ATP-Dependent RNA Helicase, OseIF4A, in Rice. J Mol Biol 2013; 425:2853-66. [DOI: 10.1016/j.jmb.2013.05.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 05/17/2013] [Accepted: 05/28/2013] [Indexed: 12/12/2022]
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Nyikó T, Kerényi F, Szabadkai L, Benkovics AH, Major P, Sonkoly B, Mérai Z, Barta E, Niemiec E, Kufel J, Silhavy D. Plant nonsense-mediated mRNA decay is controlled by different autoregulatory circuits and can be induced by an EJC-like complex. Nucleic Acids Res 2013; 41:6715-28. [PMID: 23666629 PMCID: PMC3711448 DOI: 10.1093/nar/gkt366] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a eukaryotic quality control system that recognizes and degrades transcripts containing NMD cis elements in their 3′untranslated region (UTR). In yeasts, unusually long 3′UTRs act as NMD cis elements, whereas in vertebrates, NMD is induced by introns located >50 nt downstream from the stop codon. In vertebrates, splicing leads to deposition of exon junction complex (EJC) onto the mRNA, and then 3′UTR-bound EJCs trigger NMD. It is proposed that this intron-based NMD is vertebrate specific, and it evolved to eliminate the misproducts of alternative splicing. Here, we provide evidence that similar EJC-mediated intron-based NMD functions in plants, suggesting that this type of NMD is evolutionary conserved. We demonstrate that in plants, like in vertebrates, introns located >50 nt from the stop induces NMD. We show that orthologs of all core EJC components are essential for intron-based plant NMD and that plant Partner of Y14 and mago (PYM) also acts as EJC disassembly factor. Moreover, we found that complex autoregulatory circuits control the activity of plant NMD. We demonstrate that expression of suppressor with morphogenic effect on genitalia (SMG)7, which is essential for long 3′UTR- and intron-based NMD, is regulated by both types of NMD, whereas expression of Barentsz EJC component is downregulated by intron-based NMD.
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Affiliation(s)
- Tünde Nyikó
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Farkas Kerényi
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Levente Szabadkai
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Anna H. Benkovics
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Péter Major
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Boglárka Sonkoly
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Zsuzsanna Mérai
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Endre Barta
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Emilia Niemiec
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Joanna Kufel
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Dániel Silhavy
- Agricultural Biotechnology Center, Institute for Genetics, Szent-Györgyi 4, H-2100, Gödöllő, Hungary, Gregor Mendel Institute, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria, Albert-Ludwigs-Universitat Freiburg, Institut fur Biologie II/Botanik, Schanzlestrasse 1, D-79104 Freiburg, Germany and Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
- *To whom correspondence should be addressed. Tel: +36 28 526 194; Fax: +36 28 526 145;
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