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Lewinski M, Steffen A, Kachariya N, Elgner M, Schmal C, Messini N, Köster T, Reichel M, Sattler M, Zarnack K, Staiger D. Arabidopsis thaliana GLYCINE RICH RNA-BINDING PROTEIN 7 interaction with its iCLIP target LHCB1.1 correlates with changes in RNA stability and circadian oscillation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 118:203-224. [PMID: 38124335 DOI: 10.1111/tpj.16601] [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: 08/25/2023] [Accepted: 12/09/2023] [Indexed: 12/23/2023]
Abstract
The importance of RNA-binding proteins (RBPs) for plant responses to environmental stimuli and development is well documented. Insights into the portfolio of RNAs they recognize, however, clearly lack behind the understanding gathered in non-plant model organisms. Here, we characterize binding of the circadian clock-regulated Arabidopsis thaliana GLYCINE-RICH RNA-BINDING PROTEIN 7 (AtGRP7) to its target transcripts. We identified novel RNA targets from individual-nucleotide resolution UV crosslinking and immunoprecipitation (iCLIP) data using an improved bioinformatics pipeline that will be broadly applicable to plant RBP iCLIP data. 2705 transcripts with binding sites were identified in plants expressing AtGRP7-GFP that were not recovered in plants expressing an RNA-binding dead variant or GFP alone. A conserved RNA motif enriched in uridine residues was identified at the AtGRP7 binding sites. NMR titrations confirmed the preference of AtGRP7 for RNAs with a central U-rich motif. Among the bound RNAs, circadian clock-regulated transcripts were overrepresented. Peak abundance of the LHCB1.1 transcript encoding a chlorophyll-binding protein was reduced in plants overexpressing AtGRP7 whereas it was elevated in atgrp7 mutants, indicating that LHCB1.1 was regulated by AtGRP7 in a dose-dependent manner. In plants overexpressing AtGRP7, the LHCB1.1 half-life was shorter compared to wild-type plants whereas in atgrp7 mutant plants, the half-life was significantly longer. Thus, AtGRP7 modulates circadian oscillations of its in vivo binding target LHCB1.1 by affecting RNA stability.
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Affiliation(s)
- Martin Lewinski
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Alexander Steffen
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Nitin Kachariya
- Helmholtz Munich, Molecular Targets and Therapeutics Center, Institute of Structural Biology, Neuherberg, 85764, Germany
- Department of Bioscience, Bavarian NMR Center, Technical University of Munich, TUM School of Natural Sciences, Garching, 85747, Germany
| | - Mareike Elgner
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Christoph Schmal
- Institute for Theoretical Biology, Humboldt-Universität zu Berlin and Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Niki Messini
- Helmholtz Munich, Molecular Targets and Therapeutics Center, Institute of Structural Biology, Neuherberg, 85764, Germany
- Department of Bioscience, Bavarian NMR Center, Technical University of Munich, TUM School of Natural Sciences, Garching, 85747, Germany
| | - Tino Köster
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Marlene Reichel
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Michael Sattler
- Helmholtz Munich, Molecular Targets and Therapeutics Center, Institute of Structural Biology, Neuherberg, 85764, Germany
- Department of Bioscience, Bavarian NMR Center, Technical University of Munich, TUM School of Natural Sciences, Garching, 85747, Germany
| | - Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences (BMLS) & Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt, Germany
| | - Dorothee Staiger
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
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Shim JS, Park SH, Lee DK, Kim YS, Park SC, Redillas MCFR, Seo JS, Kim JK. The Rice GLYCINE-RICH PROTEIN 3 Confers Drought Tolerance by Regulating mRNA Stability of ROS Scavenging-Related Genes. RICE (NEW YORK, N.Y.) 2021; 14:31. [PMID: 33742286 PMCID: PMC7979854 DOI: 10.1186/s12284-021-00473-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 03/10/2021] [Indexed: 05/08/2023]
Abstract
BACKGROUND Plant glycine-rich proteins are categorized into several classes based on their protein structures. The glycine-rich RNA binding proteins (GRPs) are members of class IV subfamily possessing N-terminus RNA-recognition motifs (RRMs) and proposed to be involved in post-transcriptional regulation of its target transcripts. GRPs are involved in developmental process and cellular stress responses, but the molecular mechanisms underlying these regulations are still elusive. RESULTS Here, we report the functional characterization of rice GLYCINE-RICH PROTEIN 3 (OsGRP3) and its physiological roles in drought stress response. Both drought stress and ABA induce the expression of OsGRP3. Transgenic plants overexpressing OsGRP3 (OsGRP3OE) exhibited tolerance while knock-down plants (OsGRP3KD) were susceptible to drought compared to the non-transgenic control. In vivo, subcellular localization analysis revealed that OsGRP3-GFP was transported from cytoplasm/nucleus into cytoplasmic foci following exposure to ABA and mannitol treatments. Comparative transcriptomic analysis between OsGRP3OE and OsGRP3KD plants suggests that OsGRP3 is involved in the regulation of the ROS related genes. RNA-immunoprecipitation analysis revealed the associations of OsGRP3 with PATHOGENESIS RELATED GENE 5 (PR5), METALLOTHIONEIN 1d (MT1d), 4,5-DOPA-DIOXYGENASE (DOPA), and LIPOXYGENASE (LOX) transcripts. The half-life analysis showed that PR5 transcripts decayed slower in OsGRP3OE but faster in OsGRP3KD, while MT1d and LOX transcripts decayed faster in OsGRP3OE but slower in OsGRP3KD plants. H2O2 accumulation was reduced in OsGRP3OE and increased in OsGRP3KD plants compared to non-transgenic plants (NT) under drought stress. CONCLUSION OsGRP3 plays a positive regulator in rice drought tolerance and modulates the transcript level and mRNA stability of stress-responsive genes, including ROS-related genes. Moreover, OsGRP3 contributes to the reduction of ROS accumulation during drought stress. Our results suggested that OsGRP3 alleviates ROS accumulation by regulating ROS-related genes' mRNA stability under drought stress, which confers drought tolerance.
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Affiliation(s)
- Jae Sung Shim
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang, 25354, South Korea
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, 61186, South Korea
| | - Su-Hyun Park
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang, 25354, South Korea
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604, Singapore
| | - Dong-Keun Lee
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang, 25354, South Korea
- E GREEN GLOBAL, Gunpo, 15843, South Korea
| | - Youn Shic Kim
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang, 25354, South Korea
- Agriculture and Life Sciences Research Institute, Kangwon National University, Chuncheon, 24341, South Korea
| | - Soo-Chul Park
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang, 25354, South Korea
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju, 54874, South Korea
| | | | - Jun Sung Seo
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang, 25354, South Korea.
| | - Ju-Kon Kim
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang, 25354, South Korea.
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Köster T, Reichel M, Staiger D. CLIP and RNA interactome studies to unravel genome-wide RNA-protein interactions in vivo in Arabidopsis thaliana. Methods 2019; 178:63-71. [PMID: 31494244 DOI: 10.1016/j.ymeth.2019.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/14/2019] [Accepted: 09/01/2019] [Indexed: 12/11/2022] Open
Abstract
Post-transcriptional regulation makes an important contribution to adjusting the transcriptome to environmental changes in plants. RNA-binding proteins are key players that interact specifically with mRNAs to co-ordinate their fate. While the regulatory interactions between proteins and RNA are well understood in animals, until recently little information was available on the global binding landscape of RNA-binding proteins in higher plants. This is not least due to technical challenges in plants. In turn, while numerous RNA-binding proteins have been identified through mutant analysis and homology-based searches in plants, only recently a full compendium of proteins with RNA-binding activity has been experimentally determined for the reference plant Arabidopsis thaliana. State-of-the-art techniques to determine RNA-protein interactions genome-wide in animals are based on the covalent fixation of RNA and protein in vivo by UV light. This has only recently been successfully applied to plants. Here, we present practical considerations on the application of UV irradiation based methods to comprehensively determine in vivo RNA-protein interactions in Arabidopsis thaliana, focussing on individual nucleotide resolution crosslinking immunoprecipitation (iCLIP) and mRNA interactome capture.
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Affiliation(s)
- Tino Köster
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
| | - Marlene Reichel
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
| | - Dorothee Staiger
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany.
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Steffen A, Elgner M, Staiger D. Regulation of Flowering Time by the RNA-Binding Proteins AtGRP7 and AtGRP8. PLANT & CELL PHYSIOLOGY 2019; 60:2040-2050. [PMID: 31241165 DOI: 10.1093/pcp/pcz124] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/18/2019] [Indexed: 05/20/2023]
Abstract
The timing of floral initiation is a tightly controlled process in plants. The circadian clock regulated glycine-rich RNA-binding protein (RBP) AtGRP7, a known regulator of splicing, was previously shown to regulate flowering time mainly by affecting the MADS-box repressor FLOWERING LOCUS C (FLC). Loss of AtGRP7 leads to elevated FLC expression and late flowering in the atgrp7-1 mutant. Here, we analyze genetic interactions of AtGRP7 with key regulators of the autonomous and the thermosensory pathway of floral induction. RNA interference- mediated reduction of the level of the paralogous AtGRP8 in atgrp7-1 further delays floral transition compared of with atgrp7-1. AtGRP7 acts in parallel to FCA, FPA and FLK in the branch of the autonomous pathway (AP) comprised of RBPs. It acts in the same branch as FLOWERING LOCUS D, and AtGRP7 loss-of-function mutants show elevated levels of dimethylated lysine 4 of histone H3, a mark for active transcription. In addition to its role in the AP, AtGRP7 acts in the thermosensory pathway of flowering time control by regulating alternative splicing of the floral repressor FLOWERING LOCUS M (FLM). Overexpression of AtGRP7 selectively favors the formation of the repressive isoform FLM-β. Our results suggest that the RBPs AtGRP7 and AtGRP8 influence MADS-Box transcription factors in at least two different pathways of flowering time control. This highlights the importance of RBPs to fine-tune the integration of varying cues into flowering time control and further strengthens the view that the different pathways, although genetically separable, constitute a tightly interwoven network to ensure plant reproductive success under changing environmental conditions.
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Affiliation(s)
- Alexander Steffen
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Universit�tsstrasse 25, D-33615 Bielefeld, Germany
| | - Mareike Elgner
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Universit�tsstrasse 25, D-33615 Bielefeld, Germany
| | - Dorothee Staiger
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Universit�tsstrasse 25, D-33615 Bielefeld, Germany
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The Photoconvertible Fluorescent Protein Dendra2 Tag as a Tool to Investigate Intracellular Protein Dynamics. Methods Mol Biol 2019; 1992:201-214. [PMID: 31148040 DOI: 10.1007/978-1-4939-9469-4_13] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Fluorescence proteins changing spectral properties after exposure to light with a specific wavelength have recently become outstanding aids in the study of intracellular protein dynamics. Herein we show using Arabidopsis SYNAPTOTAGMIN 1 as a model protein that the Dendra2 green to red photoconvertible protein tag in combination with confocal scanning laser microscopy is a useful tool to study membrane protein intracellular dynamics.
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6
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Beyond Transcription: Fine-Tuning of Circadian Timekeeping by Post-Transcriptional Regulation. Genes (Basel) 2018; 9:genes9120616. [PMID: 30544736 PMCID: PMC6315869 DOI: 10.3390/genes9120616] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 11/29/2018] [Accepted: 12/03/2018] [Indexed: 12/28/2022] Open
Abstract
The circadian clock is an important endogenous timekeeper, helping plants to prepare for the periodic changes of light and darkness in their environment. The clockwork of this molecular timer is made up of clock proteins that regulate transcription of their own genes with a 24 h rhythm. Furthermore, the rhythmically expressed clock proteins regulate time-of-day dependent transcription of downstream genes, causing messenger RNA (mRNA) oscillations of a large part of the transcriptome. On top of the transcriptional regulation by the clock, circadian rhythms in mRNAs rely in large parts on post-transcriptional regulation, including alternative pre-mRNA splicing, mRNA degradation, and translational control. Here, we present recent insights into the contribution of post-transcriptional regulation to core clock function and to regulation of circadian gene expression in Arabidopsis thaliana.
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McCormick S. A non-invasive and versatile way to assess plasmodesmatal connections. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:749-750. [PMID: 29878550 DOI: 10.1111/tpj.13946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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8
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Gerlitz N, Gerum R, Sauer N, Stadler R. Photoinducible DRONPA-s: a new tool for investigating cell-cell connectivity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:751-766. [PMID: 29654648 DOI: 10.1111/tpj.13918] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/02/2018] [Accepted: 03/26/2018] [Indexed: 06/08/2023]
Abstract
The development of multicellular plants relies on the ability of their cells to exchange solutes, proteins and signalling compounds through plasmodesmata, symplasmic pores in the plant cell wall. The aperture of plasmodesmata is regulated in response to developmental cues or external factors such as pathogen attack. This regulation enables tight control of symplasmic cell-to-cell transport. Here we report on an elegant non-invasive method to quantify the passive movement of protein between selected cells even in deeper tissue layers. The system is based on the fluorescent protein DRONPA-s, which can be switched on and off repeatedly by illumination with different light qualities. Using transgenic 35S::DRONPA-s Arabidopsis thaliana and a confocal microscope it was possible to activate DRONPA-s fluorescence in selected cells of the root meristem. This enabled us to compare movement of DRONPA-s from the activated cells into the respective neighbouring cells. Our analyses showed that pericycle cells display the highest efflux capacity with a good lateral connectivity. In contrast, root cap cells showed the lowest efflux of DRONPA-s. Plasmodesmata of quiescent centre cells mediated a stronger efflux into columella cells than into stele initials. To simplify measurements of fluorescence intensity in a complex tissue we developed software that allows simultaneous analyses of fluorescence intensities of several neighbouring cells. Our DRONPA-s system generates reproducible data and is a valuable tool for studying symplasmic connectivity.
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Affiliation(s)
- Nadja Gerlitz
- Molecular Plant Physiology, University of Erlangen, Staudtstrasse 5, Erlangen, 91058, Germany
| | - Richard Gerum
- Biophysics, University of Erlangen, Henkestrasse 91, Erlangen, 91052, Germany
| | - Norbert Sauer
- Molecular Plant Physiology, University of Erlangen, Staudtstrasse 5, Erlangen, 91058, Germany
| | - Ruth Stadler
- Molecular Plant Physiology, University of Erlangen, Staudtstrasse 5, Erlangen, 91058, Germany
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9
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Köster T, Meyer K. Plant Ribonomics: Proteins in Search of RNA Partners. TRENDS IN PLANT SCIENCE 2018; 23:352-365. [PMID: 29429586 DOI: 10.1016/j.tplants.2018.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/08/2018] [Accepted: 01/15/2018] [Indexed: 06/08/2023]
Abstract
Research into the regulation of gene expression underwent a shift from focusing on DNA-binding proteins as key transcriptional regulators to RNA-binding proteins (RBPs) that come into play once transcription has been initiated. RBPs orchestrate all RNA-processing steps in the cell. To obtain a global view of in vivo targets, the RNA complement associated with particular RBPs is determined via immunoprecipitation of the RBP and subsequent identification of bound RNAs via RNA-seq. Here, we describe technical advances in identifying RBP in vivo targets and their binding motifs. We provide an up-to-date view of targets of nucleocytoplasmic RBPs collected in arabidopsis. We also discuss current experimental limitations and provide an outlook on how the approaches may advance our understanding of post-transcriptional networks.
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Affiliation(s)
- Tino Köster
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany.
| | - Katja Meyer
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
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10
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Evolution and characterization of a new reversibly photoswitching chromogenic protein, Dathail. J Mol Biol 2016; 428:1776-89. [DOI: 10.1016/j.jmb.2016.02.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 02/27/2016] [Accepted: 02/29/2016] [Indexed: 12/11/2022]
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11
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Komis G, Šamajová O, Ovečka M, Šamaj J. Super-resolution Microscopy in Plant Cell Imaging. TRENDS IN PLANT SCIENCE 2015; 20:834-843. [PMID: 26482957 DOI: 10.1016/j.tplants.2015.08.013] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 07/20/2015] [Accepted: 08/26/2015] [Indexed: 05/20/2023]
Abstract
Although the development of super-resolution microscopy methods dates back to 1994, relevant applications in plant cell imaging only started to emerge in 2010. Since then, the principal super-resolution methods, including structured-illumination microscopy (SIM), photoactivation localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), and stimulated emission depletion microscopy (STED), have been implemented in plant cell research. However, progress has been limited due to the challenging properties of plant material. Here we summarize the basic principles of existing super-resolution methods and provide examples of applications in plant science. The limitations imposed by the nature of plant material are reviewed and the potential for future applications in plant cell imaging is highlighted.
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Affiliation(s)
- George Komis
- Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University Olomouc, Faculty of Science, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Olga Šamajová
- Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University Olomouc, Faculty of Science, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Miroslav Ovečka
- Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University Olomouc, Faculty of Science, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Jozef Šamaj
- Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University Olomouc, Faculty of Science, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
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12
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Lewinski M, Hallmann A, Staiger D. Genome-wide identification and phylogenetic analysis of plant RNA binding proteins comprising both RNA recognition motifs and contiguous glycine residues. Mol Genet Genomics 2015; 291:763-73. [DOI: 10.1007/s00438-015-1144-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/06/2015] [Indexed: 11/28/2022]
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13
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Krenek P, Samajova O, Luptovciak I, Doskocilova A, Komis G, Samaj J. Transient plant transformation mediated by Agrobacterium tumefaciens: Principles, methods and applications. Biotechnol Adv 2015; 33:1024-42. [PMID: 25819757 DOI: 10.1016/j.biotechadv.2015.03.012] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 03/05/2015] [Accepted: 03/19/2015] [Indexed: 12/20/2022]
Abstract
Agrobacterium tumefaciens is widely used as a versatile tool for development of stably transformed model plants and crops. However, the development of Agrobacterium based transient plant transformation methods attracted substantial attention in recent years. Transient transformation methods offer several applications advancing stable transformations such as rapid and scalable recombinant protein production and in planta functional genomics studies. Herein, we highlight Agrobacterium and plant genetics factors affecting transfer of T-DNA from Agrobacterium into the plant cell nucleus and subsequent transient transgene expression. We also review recent methods concerning Agrobacterium mediated transient transformation of model plants and crops and outline key physical, physiological and genetic factors leading to their successful establishment. Of interest are especially Agrobacterium based reverse genetics studies in economically important crops relying on use of RNA interference (RNAi) or virus-induced gene silencing (VIGS) technology. The applications of Agrobacterium based transient plant transformation technology in biotech industry are presented in thorough detail. These involve production of recombinant proteins (plantibodies, vaccines and therapeutics) and effectoromics-assisted breeding of late blight resistance in potato. In addition, we also discuss biotechnological potential of recombinant GFP technology and present own examples of successful Agrobacterium mediated transient plant transformations.
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Affiliation(s)
- Pavel Krenek
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - Olga Samajova
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - Ivan Luptovciak
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - Anna Doskocilova
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - George Komis
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - Jozef Samaj
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
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Ciuzan O, Hancock J, Pamfil D, Wilson I, Ladomery M. The evolutionarily conserved multifunctional glycine-rich RNA-binding proteins play key roles in development and stress adaptation. PHYSIOLOGIA PLANTARUM 2015; 153:1-11. [PMID: 25243592 DOI: 10.1111/ppl.12286] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 08/11/2014] [Accepted: 08/20/2014] [Indexed: 05/24/2023]
Abstract
The class IV glycine-rich RNA-binding proteins are a distinct subgroup within the heterogenous superfamily of glycine-rich proteins (GRPs). They are distinguished by the presence of an RNA-binding domain in the N-terminus; generally in the form of an RNA-recognition motif (RRM) or a cold-shock domain (CSD). These are followed by a C-terminal glycine-rich domain. Growing evidence suggests that these proteins play key roles in the adaptation of organisms to biotic and abiotic stresses including those resulting from pathogenesis, alterations in the osmotic, saline and oxidative environment and changes in temperature. Similar vertebrate proteins are also cold-induced and involved in, e.g. hibernation, suggesting evolutionarily conserved functions. The class IV RNA-binding GRPs are likely to operate as key molecular components of hormonally regulated development and to work by regulating gene expression at multiple levels by modifying alternative splicing, mRNA export, mRNA translation and mRNA degradation.
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Affiliation(s)
- Oana Ciuzan
- University of Agricultural Science and Veterinary Medicine Cluj-Napoca, Cluj-Napoca, 400372, Romania; Molecular Cell Physiology, Faculty of Biology, Bielefeld University, Bielefeld, D-33615, Germany
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15
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Yeap WC, Namasivayam P, Ho CL. HnRNP-like proteins as post-transcriptional regulators. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 227:90-100. [PMID: 25219311 DOI: 10.1016/j.plantsci.2014.07.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/17/2014] [Accepted: 07/18/2014] [Indexed: 05/23/2023]
Abstract
Plant cells contain a diverse repertoire of RNA-binding proteins (RBPs) that coordinate a network of post-transcriptional regulation. RBPs govern diverse developmental processes by modulating the gene expression of specific transcripts. Recent gene annotation and RNA sequencing clearly showed that heterogeneous nuclear ribonucleoprotein (hnRNP)-like proteins which form a family of RBPs, are also expressed in higher plants and serve specific plant functions. In addition to their involvement in post-transcriptional regulation from mRNA capping to translation, they are also involved in telomere regulation, gene silencing and regulation in chloroplast. Here, we review the involvement of plant hnRNP-like proteins in post-transcription regulation of RNA processes and their functional roles in control of plant developmental processes especially plant-specific functions including flowering, chloroplastic-specific mRNA regulation, long-distance phloem transportation and plant responses to environmental stresses.
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Affiliation(s)
- Wan-Chin Yeap
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Sime Darby Technology Centre Sdn. Bhd., 1st Floor, Block B, UPM-MTDC Technology Centre III, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Parameswari Namasivayam
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Chai-Ling Ho
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
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Leder V, Lummer M, Tegeler K, Humpert F, Lewinski M, Schüttpelz M, Staiger D. Mutational definition of binding requirements of an hnRNP-like protein in Arabidopsis using fluorescence correlation spectroscopy. Biochem Biophys Res Commun 2014; 453:69-74. [PMID: 25251471 DOI: 10.1016/j.bbrc.2014.09.056] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 09/15/2014] [Indexed: 12/23/2022]
Abstract
Arabidopsis thaliana glycine-rich RNA binding protein 7 (AtGRP7) is part of a negative feedback loop through which it regulates alternative splicing and steady-state abundance of its pre-mRNA. Here we use fluorescence correlation spectroscopy to investigate the requirements for AtGRP7 binding to its intron using fluorescently-labelled synthetic oligonucleotides. By systematically introducing point mutations we identify three nucleotides that lead to an increased Kd value when mutated and thus are critical for AtGRP7 binding. Simultaneous mutation of all three residues abrogates binding. The paralogue AtGRP8 binds to an overlapping motif but with a different sequence preference, in line with overlapping but not identical functions of this protein pair. Truncation of the glycine-rich domain reduces the binding affinity of AtGRP7, showing for the first time that the glycine-rich stretch of a plant hnRNP-like protein contributes to binding. Mutation of the conserved R(49) that is crucial for AtGRP7 function in pathogen defence and splicing abolishes binding.
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Affiliation(s)
- Verena Leder
- Molecular Cell Physiology, Faculty of Biology, Bielefeld University, Germany; Biomolecular Photonics, Faculty of Physics, Bielefeld University, Germany
| | - Martina Lummer
- Molecular Cell Physiology, Faculty of Biology, Bielefeld University, Germany
| | - Kathrin Tegeler
- Molecular Cell Physiology, Faculty of Biology, Bielefeld University, Germany; Biomolecular Photonics, Faculty of Physics, Bielefeld University, Germany
| | - Fabian Humpert
- Biomolecular Photonics, Faculty of Physics, Bielefeld University, Germany
| | - Martin Lewinski
- Molecular Cell Physiology, Faculty of Biology, Bielefeld University, Germany
| | - Mark Schüttpelz
- Biomolecular Photonics, Faculty of Physics, Bielefeld University, Germany
| | - Dorothee Staiger
- Molecular Cell Physiology, Faculty of Biology, Bielefeld University, Germany.
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17
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Köster T, Meyer K, Weinholdt C, Smith LM, Lummer M, Speth C, Grosse I, Weigel D, Staiger D. Regulation of pri-miRNA processing by the hnRNP-like protein AtGRP7 in Arabidopsis. Nucleic Acids Res 2014; 42:9925-36. [PMID: 25104024 PMCID: PMC4150807 DOI: 10.1093/nar/gku716] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The hnRNP-like glycine-rich RNA-binding protein AtGRP7 regulates pre-mRNA splicing in Arabidopsis. Here we used small RNA-seq to show that AtGRP7 also affects the miRNA inventory. AtGRP7 overexpression caused a significant reduction in the level of 30 miRNAs and an increase for 14 miRNAs with a minimum log2 fold change of ± 0.5. Overaccumulation of several pri-miRNAs including pri-miR398b, pri-miR398c, pri-miR172b, pri-miR159a and pri-miR390 at the expense of the mature miRNAs suggested that AtGRP7 affects pri-miRNA processing. Indeed, RNA immunoprecipitation revealed that AtGRP7 interacts with these pri-miRNAs in vivo. Mutation of an arginine in the RNA recognition motif abrogated in vivo binding and the effect on miRNA and pri-miRNA levels, indicating that AtGRP7 inhibits processing of these pri-miRNAs by direct binding. In contrast, pri-miRNAs of selected miRNAs that were elevated or not changed in response to high AtGRP7 levels were not bound in vivo. Reduced accumulation of miR390, an initiator of trans-acting small interfering RNA (ta-siRNA) formation, also led to lower TAS3 ta-siRNA levels and increased mRNA expression of the target AUXIN RESPONSE FACTOR4. Furthermore, AtGRP7 affected splicing of pri-miR172b and pri-miR162a. Thus, AtGRP7 is an hnRNP-like protein with a role in processing of pri-miRNAs in addition to its role in pre-mRNA splicing.
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Affiliation(s)
- Tino Köster
- Molecular Cell Physiology, Bielefeld University
| | - Katja Meyer
- Molecular Cell Physiology, Bielefeld University
| | - Claus Weinholdt
- Institute of Computer Science, Martin-Luther-University Halle-Wittenberg, Germany
| | - Lisa M Smith
- Max Planck Institute for Developmental Biology, Tuebingen, Germany Department of Animal & Plant Sciences, University of Sheffield, UK
| | | | - Corinna Speth
- Max Planck Institute for Developmental Biology, Tuebingen, Germany Center for Plant Molecular Biology, University of Tuebingen Chemical Genomics Centre of the Max Planck Society, Dortmund, Germany
| | - Ivo Grosse
- Institute of Computer Science, Martin-Luther-University Halle-Wittenberg, Germany German Centre for Integrative Biodiversity Research Halle-Jena-Leipzig, Germany
| | - Detlef Weigel
- Max Planck Institute for Developmental Biology, Tuebingen, Germany
| | - Dorothee Staiger
- Molecular Cell Physiology, Bielefeld University Institute for Genome Research & Systems Biology, CeBiTec, Bielefeld, Germany
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18
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Hackmann C, Korneli C, Kutyniok M, Köster T, Wiedenlübbert M, Müller C, Staiger D. Salicylic acid-dependent and -independent impact of an RNA-binding protein on plant immunity. PLANT, CELL & ENVIRONMENT 2014; 37:696-706. [PMID: 23961939 DOI: 10.1111/pce.12188] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 08/09/2013] [Accepted: 08/15/2013] [Indexed: 05/08/2023]
Abstract
Plants overexpressing the RNA-binding protein AtGRP7 (AtGRP7-ox plants) constitutively express the PR-1 (PATHOGENESIS-RELATED-1), PR-2 and PR-5 transcripts associated with salicylic acid (SA)-mediated immunity and show enhanced resistance against Pseudomonas syringae pv. tomato (Pto) DC3000. Here, we investigated whether the function of AtGRP7 in plant immunity depends on SA. Endogenous SA was elevated fivefold in AtGRP7-ox plants. The elevated PR-1, PR-2 and PR-5 levels were eliminated upon expression of the salicylate hydroxylase nahG in AtGRP7-ox plants and elevated PR-1 levels were suppressed by sid (salicylic acid deficient) 2-1 that is impaired in SA biosynthesis. RNA immunoprecipitation showed that AtGRP7 does not bind the PR-1 transcript in vivo, whereas it binds PDF1.2. Constitutive or inducible AtGRP7 overexpression increases PR-1 promoter activity, indicating that AtGRP7 affects PR-1 transcription. In line with this, the effect of AtGRP7 on PR-1 is suppressed by npr (non-expressor of PR genes) 1. Whereas AtGRP7-ox plants restricted growth of Pto DC3000 compared with wild type (wt), sid2-1 AtGRP7-ox plants allowed more growth than AtGRP7-ox plants. Furthermore, we show an enhanced hypersensitive response triggered by avirulent Pto DC3000 (AvrRpt2) in AtGRP7-ox compared with wt. In sid2-1 AtGRP7-ox, an intermediate phenotype was observed. Thus, AtGRP7 has both SA-dependent and SA-independent effects on plant immunity.
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Affiliation(s)
- Christian Hackmann
- Department of Molecular Cell Physiology, Bielefeld University, Universitätsstraße 25, D-33615, Bielefeld, Germany; Institute for Genome Research and Systems Biology, CeBiTec, Bielefeld University, Universitätsstraße 25, D-33615, Bielefeld, Germany
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19
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Abstract
Over the past decade, confocal microscopy and the ever-expanding toolchest of fluorescent protein (xFP) markers and technologies have become routine methods for the biological laboratory. A common use of xFP fluorophores is in localizing proteins and the subcellular structures with which they associate, including analyzing their distribution and dynamics and the interactions of proteins in vivo. Additionally, a number of so-called optical highlighters have proven especially useful in analyzing the kinetics of these processes in pulse-chase studies of protein relocation(s) following an experimental challenge. Here we focus on exemplary methods in transformation and live-cell imaging in plant cells, with the expectation that researchers will find these and the accompanying resources useful as a starting point in developing their own expertise.
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Affiliation(s)
- Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
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20
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Abstract
Optical microscopy has developed as an indispensable tool for Arabidopsis cell biology. This is due to the high sensitivity, good spatial resolution, minimal invasiveness, and availability of autofluorescent proteins, which can be specifically fused to a distinct protein of interest. In this chapter, we introduce the theoretical concepts of fluorescence emission necessary to accomplish quantitative and functional cell biology using optical microscopy. The main focus lies on spectroscopic techniques, which, in addition to intensity-based studies, provide functional insight into cellular processes.
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21
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Löhr B, Streitner C, Steffen A, Lange T, Staiger D. A glycine-rich RNA-binding protein affects gibberellin biosynthesis in Arabidopsis. Mol Biol Rep 2013; 41:439-45. [DOI: 10.1007/s11033-013-2878-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 11/19/2013] [Indexed: 12/29/2022]
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22
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Lummer M, Humpert F, Wiedenlübbert M, Sauer M, Schüttpelz M, Staiger D. A new set of reversibly photoswitchable fluorescent proteins for use in transgenic plants. MOLECULAR PLANT 2013; 6:1518-30. [PMID: 23434876 DOI: 10.1093/mp/sst040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Fluorescent reporter proteins that allow repeated switching between a fluorescent and a non-fluorescent state in response to specific wavelengths of light are novel tools for monitoring of protein trafficking and super-resolution fluorescence microscopy in living organisms. Here, we describe variants of the reversibly photoswitchable fluorescent proteins rsFastLime, bsDronpa, and Padron that have been codon-optimized for the use in transgenic Arabidopsis plants. The synthetic proteins, designated rsFastLIME-s, bsDRONPA-s, and PADRON C-s, showed photophysical properties and switching behavior comparable to those reported for the original proteins. By combining the 'positively switchable' PADRON C-s with the 'negatively switchable' rsFastLIME-s or bsDRONPA-s, two different fluorescent reporter proteins could be imaged at the same wavelength upon transient expression in Nicotiana benthamiana cells. Thus, co-localization analysis can be performed using only a single detection channel. Furthermore, the proteins were used to tag the RNA-binding protein AtGRP7 (Arabidopsis thaliana glycine-rich RNA-binding protein 7) in transgenic Arabidopsis plants. Because the new reversibly photoswitchable fluorescent proteins show an increase in signal strength during each photoactivation cycle, we were able to generate a large number of scans of the same region and reconstruct 3-D images of AtGRP7 expression in the root tip. Upon photoactivation of the AtGRP7:rsFastLIME-s fusion protein in a defined region of a transgenic Arabidopsis root, spreading of the fluorescence signal into adjacent regions was observed, indicating that movement from cell to cell can be monitored. Our results demonstrate that rsFastLIME-s, bsDRONPA-s, and PADRON C-s are versatile fluorescent markers in plants. Furthermore, the proteins also show strong fluorescence in mammalian cells including COS-7 and HeLa cells.
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Affiliation(s)
- Martina Lummer
- Molecular Cell Physiology, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany
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23
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Tiwari DK, Nagai T. Smart fluorescent proteins: Innovation for barrier-free superresolution imaging in living cells. Dev Growth Differ 2013; 55:491-507. [DOI: 10.1111/dgd.12064] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Revised: 03/06/2013] [Accepted: 03/22/2013] [Indexed: 01/08/2023]
Affiliation(s)
- Dhermendra K. Tiwari
- The Institute of Scientific and Industrial Research; Osaka University; Mihogaoka 8-1; Ibaraki; Osaka; 567-0047; Japan
| | - Takeharu Nagai
- The Institute of Scientific and Industrial Research; Osaka University; Mihogaoka 8-1; Ibaraki; Osaka; 567-0047; Japan
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24
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Schmal C, Reimann P, Staiger D. A circadian clock-regulated toggle switch explains AtGRP7 and AtGRP8 oscillations in Arabidopsis thaliana. PLoS Comput Biol 2013; 9:e1002986. [PMID: 23555221 PMCID: PMC3610657 DOI: 10.1371/journal.pcbi.1002986] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Accepted: 01/29/2013] [Indexed: 12/25/2022] Open
Abstract
The circadian clock controls many physiological processes in higher plants and causes a large fraction of the genome to be expressed with a 24h rhythm. The transcripts encoding the RNA-binding proteins AtGRP7 (Arabidopsis thaliana Glycine Rich Protein 7) and AtGRP8 oscillate with evening peaks. The circadian clock components CCA1 and LHY negatively affect AtGRP7 expression at the level of transcription. AtGRP7 and AtGRP8, in turn, negatively auto-regulate and reciprocally cross-regulate post-transcriptionally: high protein levels promote the generation of an alternative splice form that is rapidly degraded. This clock-regulated feedback loop has been proposed to act as a molecular slave oscillator in clock output. While mathematical models describing the circadian core oscillator in Arabidopsis thaliana were introduced recently, we propose here the first model of a circadian slave oscillator. We define the slave oscillator in terms of ordinary differential equations and identify the model's parameters by an optimization procedure based on experimental results. The model successfully reproduces the pertinent experimental findings such as waveforms, phases, and half-lives of the time-dependent concentrations. Furthermore, we obtain insights into possible mechanisms underlying the observed experimental dynamics: the negative auto-regulation and reciprocal cross-regulation via alternative splicing could be responsible for the sharply peaking waveforms of the AtGRP7 and AtGRP8 mRNA. Moreover, our results suggest that the AtGRP8 transcript oscillations are subordinated to those of AtGRP7 due to a higher impact of AtGRP7 protein on alternative splicing of its own and of the AtGRP8 pre-mRNA compared to the impact of AtGRP8 protein. Importantly, a bifurcation analysis provides theoretical evidence that the slave oscillator could be a toggle switch, arising from the reciprocal cross-regulation at the post-transcriptional level. In view of this, transcriptional repression of AtGRP7 and AtGRP8 by LHY and CCA1 induces oscillations of the toggle switch, leading to the observed high-amplitude oscillations of AtGRP7 mRNA. The circadian clock organizes the day in the life of a plant by causing 24h rhythms in gene expression. For example, the core clockwork of the model plant Arabidopsis thaliana causes the transcripts encoding the RNA-binding proteins AtGRP7 and AtGRP8 to undergo high amplitude oscillations with a peak at the end of the day. AtGRP7 and AtGRP8, in turn, negatively auto-regulate and reciprocally cross-regulate their own expression by causing alternative splicing of their pre-mRNAs, followed by rapid degradation of the alternatively spliced transcripts. This has led to the suggestion that they represent molecular slave oscillators downstream of the core clock. Using a mathematical model we obtain insights into possible mechanisms underlying the experimentally observed dynamics, e.g. a higher impact of AtGRP7 protein compared to the impact of AtGRP8 protein on the alternative splicing explains the experimentally observed phases of their transcript. Previously, components that reciprocally repress their own transcription (double negative loops) have been shown to potentially act as a toggle switch between two states. We provide theoretical evidence that the slave oscillator could be a bistable toggle switch as well, operating at the post-transcriptional level.
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Affiliation(s)
- Christoph Schmal
- Condensed Matter Theory, Faculty of Physics, Bielefeld University, Bielefeld, Germany.
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25
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Nicaise V, Joe A, Jeong BR, Korneli C, Boutrot F, Westedt I, Staiger D, Alfano JR, Zipfel C. Pseudomonas HopU1 modulates plant immune receptor levels by blocking the interaction of their mRNAs with GRP7. EMBO J 2013; 32:701-12. [PMID: 23395902 DOI: 10.1038/emboj.2013.15] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 01/09/2013] [Indexed: 02/01/2023] Open
Abstract
Pathogens target important components of host immunity to cause disease. The Pseudomonas syringae type III-secreted effector HopU1 is a mono-ADP-ribosyltransferase required for full virulence on Arabidopsis thaliana. HopU1 targets several RNA-binding proteins including GRP7, whose role in immunity is still unclear. Here, we show that GRP7 associates with translational components, as well as with the pattern recognition receptors FLS2 and EFR. Moreover, GRP7 binds specifically FLS2 and EFR transcripts in vivo through its RNA recognition motif. HopU1 does not affect the protein-protein associations between GRP7, FLS2 and translational components. Instead, HopU1 blocks the interaction between GRP7 and FLS2 and EFR transcripts in vivo. This inhibition correlates with reduced FLS2 protein levels upon Pseudomonas infection in a HopU1-dependent manner. Our results reveal a novel virulence strategy used by a microbial effector to interfere with host immunity.
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Affiliation(s)
- Valerie Nicaise
- The Sainsbury Laboratory, Norwich Research Park, Norwich, UK
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26
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Wolf A, Akrap N, Marg B, Galliardt H, Heiligentag M, Humpert F, Sauer M, Kaltschmidt B, Kaltschmidt C, Seidel T. Elements of transcriptional machinery are compatible among plants and mammals. PLoS One 2013; 8:e53737. [PMID: 23326494 PMCID: PMC3543382 DOI: 10.1371/journal.pone.0053737] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Accepted: 12/03/2012] [Indexed: 12/25/2022] Open
Abstract
In the present work, the objective has been to analyse the compatibility of plant and human transcriptional machinery. The experiments revealed that nuclear import and export are conserved among plants and mammals. Further it has been shown that transactivation of a human promoter occurs by human transcription factor NF-κB in plant cells, demonstrating that the transcriptional machinery is highly conserved in both kingdoms. Functionality was also seen for regulatory elements of NF-κB such as its inhibitor IκB isoform α that negatively regulated the transactivation activity of the p50/RelA heterodimer by interaction with NF-κB in plant cells. Nuclear export of RelA could be demonstrated by FRAP-measurements so that RelA shows nucleo-cytoplasmic shuttling as reported for RelA in mammalian cells. The data reveals the high level of compatibility of human transcriptional elements with the plant transcriptional machinery. Thus, Arabidopsis thaliana mesophyll protoplasts might provide a new heterologous expression system for the investigation of the human NF-κB signaling pathways. The system successfully enabled the controlled manipulation of NF-κB activity. We suggest the plant protoplast system as a tool for reconstitution and analyses of mammalian pathways and for direct observation of responses to e.g. pharmaceuticals. The major advantage of the system is the absence of interference with endogenous factors that affect and crosstalk with the pathway.
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Affiliation(s)
- Annette Wolf
- Dynamic Cell Imaging, University of Bielefeld, Bielefeld, Germany
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27
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Staiger D, Korneli C, Lummer M, Navarro L. Emerging role for RNA-based regulation in plant immunity. THE NEW PHYTOLOGIST 2013; 197:394-404. [PMID: 23163405 DOI: 10.1111/nph.12022] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 10/02/2012] [Indexed: 05/20/2023]
Abstract
Infection by phytopathogenic bacteria triggers massive changes in plant gene expression, which are thought to be mostly a result of transcriptional reprogramming. However, evidence is accumulating that plants additionally use post-transcriptional regulation of immune-responsive mRNAs as a strategic weapon to shape the defense-related transcriptome. Cellular RNA-binding proteins regulate RNA stability, splicing or mRNA export of immune-response transcripts. In particular, mutants defective in alternative splicing of resistance genes exhibit compromised disease resistance. Furthermore, detection of bacterial pathogens induces the differential expression of small non-coding RNAs including microRNAs that impact the host defense transcriptome. Phytopathogenic bacteria in turn have evolved effector proteins to inhibit biogenesis and/or activity of cellular microRNAs. Whereas RNA silencing has long been known as an antiviral defense response, recent findings also reveal a major role of this process in antibacterial defense. Here we review the function of RNA-binding proteins and small RNA-directed post-transcriptional regulation in antibacterial defense. We mainly focus on studies that used the model system Arabidopsis thaliana and also discuss selected examples from other plants.
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Affiliation(s)
- Dorothee Staiger
- Molecular Cell Physiology, Bielefeld University, D-33615, Bielefeld, Germany
- Institute for Genome Research and Systems Biology, CeBiTec, Bielefeld University, D-33615, Bielefeld, Germany
| | - Christin Korneli
- Molecular Cell Physiology, Bielefeld University, D-33615, Bielefeld, Germany
- Institute for Genome Research and Systems Biology, CeBiTec, Bielefeld University, D-33615, Bielefeld, Germany
| | - Martina Lummer
- Molecular Cell Physiology, Bielefeld University, D-33615, Bielefeld, Germany
- Institute for Genome Research and Systems Biology, CeBiTec, Bielefeld University, D-33615, Bielefeld, Germany
| | - Lionel Navarro
- Institut de Biologie de L'Ecole Normale Supérieure (IBENS), 46 Rue d'Ulm, 75230, Paris Cedex 05, France
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28
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Streitner C, Köster T, Simpson CG, Shaw P, Danisman S, Brown JWS, Staiger D. An hnRNP-like RNA-binding protein affects alternative splicing by in vivo interaction with transcripts in Arabidopsis thaliana. Nucleic Acids Res 2012; 40:11240-55. [PMID: 23042250 PMCID: PMC3526319 DOI: 10.1093/nar/gks873] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Alternative splicing (AS) of pre-mRNAs is an important regulatory mechanism shaping the transcriptome. In plants, only few RNA-binding proteins are known to affect AS. Here, we show that the glycine-rich RNA-binding protein AtGRP7 influences AS in Arabidopsis thaliana. Using a high-resolution RT–PCR-based AS panel, we found significant changes in the ratios of AS isoforms for 59 of 288 analyzed AS events upon ectopic AtGRP7 expression. In particular, AtGRP7 affected the choice of alternative 5′ splice sites preferentially. About half of the events are also influenced by the paralog AtGRP8, indicating that AtGRP7 and AtGRP8 share a network of downstream targets. For 10 events, the AS patterns were altered in opposite directions in plants with elevated AtGRP7 level or lacking AtGRP7. Importantly, RNA immunoprecipitation from plant extracts showed that several transcripts are bound by AtGRP7 in vivo and indeed represent direct targets. Furthermore, the effect of AtGRP7 on these AS events was abrogated by mutation of a single arginine that is required for its RNA-binding activity. This indicates that AtGRP7 impacts AS of these transcripts via direct interaction. As several of the AS events are also controlled by other splicing regulators, our data begin to provide insights into an AS network in Arabidopsis.
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29
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Reddy ASN, Day IS, Göhring J, Barta A. Localization and dynamics of nuclear speckles in plants. PLANT PHYSIOLOGY 2012; 158:67-77. [PMID: 22045923 PMCID: PMC3252098 DOI: 10.1104/pp.111.186700] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 10/31/2011] [Indexed: 05/17/2023]
Affiliation(s)
- Anireddy S N Reddy
- Department of Biology, Program in Molecular Plant Biology, Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA.
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30
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Staiger D, Green R. RNA-based regulation in the plant circadian clock. TRENDS IN PLANT SCIENCE 2011; 16:517-523. [PMID: 21782493 DOI: 10.1016/j.tplants.2011.06.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 06/03/2011] [Accepted: 06/14/2011] [Indexed: 05/31/2023]
Abstract
The circadian clock is an endogenous, approximately 24-h timer that enables plants to anticipate daily changes in their environment and regulates a considerable fraction of the transcriptome. At the core of the circadian system is the oscillator, made up of interconnected feedback loops, involving transcriptional regulation of clock genes and post-translational modification of clock proteins. Recently, it has become clear that post-transcriptional events are also critical for shaping rhythmic mRNA and protein profiles. This review covers regulation at the RNA level of both the core clock and output genes in Arabidopsis (Arabidopsis thaliana), with comparisons with other model organisms. We discuss the role of splicing, mRNA decay and translational regulation as well as recent insights into rhythms of noncoding regulatory RNAs.
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Affiliation(s)
- Dorothee Staiger
- Molecular Cell Physiology, Bielefeld University, D-33501 Bielefeld, Germany.
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