1
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Blagojevic A, Baldrich P, Schiaffini M, Lechner E, Baumberger N, Hammann P, Elmayan T, Garcia D, Vaucheret H, Meyers BC, Genschik P. Heat stress promotes Arabidopsis AGO1 phase separation and association with stress granule components. iScience 2024; 27:109151. [PMID: 38384836 PMCID: PMC10879784 DOI: 10.1016/j.isci.2024.109151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/17/2023] [Accepted: 02/01/2024] [Indexed: 02/23/2024] Open
Abstract
In Arabidopsis thaliana, ARGONAUTE1 (AGO1) plays a central role in microRNA (miRNA) and small interfering RNA (siRNA)-mediated silencing. AGO1 associates to the rough endoplasmic reticulum to conduct miRNA-mediated translational repression, mRNA cleavage, and biogenesis of phased siRNAs. Here, we show that a 37°C heat stress (HS) promotes AGO1 protein accumulation in cytosolic condensates where it colocalizes with components of siRNA bodies and of stress granules. AGO1 contains a prion-like domain in its poorly characterized N-terminal Poly-Q domain, which is sufficient to undergo phase separation independently of the presence of SGS3. HS only moderately affects the small RNA repertoire, the loading of AGO1 by miRNAs, and the signatures of target cleavage, suggesting that its localization in condensates protects AGO1 rather than promoting or impairing its activity in reprogramming gene expression during stress. Collectively, our work sheds new light on the impact of high temperature on a main effector of RNA silencing in plants.
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Affiliation(s)
- Aleksandar Blagojevic
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, 67084 Strasbourg, France
| | | | - Marlene Schiaffini
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, 67084 Strasbourg, France
| | - Esther Lechner
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, 67084 Strasbourg, France
| | - Nicolas Baumberger
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, 67084 Strasbourg, France
| | - Philippe Hammann
- Plateforme Protéomique Strasbourg Esplanade du CNRS, Université de Strasbourg, 67084 Strasbourg, France
| | - Taline Elmayan
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Damien Garcia
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, 67084 Strasbourg, France
| | - Hervé Vaucheret
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Blake C. Meyers
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
- Division of Plant Science and Technology, University of Missouri, Columbia, MO 65211, USA
| | - Pascal Genschik
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, 67084 Strasbourg, France
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2
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Kim YJ. Crosstalk between RNA silencing and RNA quality control in plants. BMB Rep 2023; 56:321-325. [PMID: 37156633 PMCID: PMC10315563 DOI: 10.5483/bmbrep.2023-0049] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 04/20/2023] [Accepted: 05/04/2023] [Indexed: 06/06/2024] Open
Abstract
RNAs are pivotal molecules acting as messengers of genetic information and regulatory molecules for cellular development and survival. From birth to death, RNAs face constant cellular decision for the precise control of cellular function and activity. Most eukaryotic cells employ conserved machineries for RNA decay including RNA silencing and RNA quality control (RQC). In plants, RQC monitors endogenous RNAs and degrades aberrant and dysfunctional species, whereas RNA silencing promotes RNA degradation to repress the expression of selected endogenous RNAs or exogenous RNA derived from transgenes and virus. Interestingly, emerging evidences have indicated that RQC and RNA silencing interact with each by sharing target RNAs and regulatory components. Such interaction should be tightly organized for proper cellular survival. However, it is still elusive that how each machinery specifically recognizes target RNAs. In this review, we summarize recent advances on RNA silencing and RQC pathway and discuss potential mechanisms underlying the interaction between the two machineries. [BMB Reports 2023; 56(6): 321-325].
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Affiliation(s)
- Yun Ju Kim
- Department of Systems Biology, Yonsei University, Seoul 03722, Korea
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3
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Bazin J, Elvira-Matelot E, Blein T, Jauvion V, Bouteiller N, Cao J, Crespi MD, Vaucheret H. Synergistic action of the Arabidopsis spliceosome components PRP39a and SmD1b in promoting posttranscriptional transgene silencing. THE PLANT CELL 2023; 35:1917-1935. [PMID: 36970782 PMCID: PMC10226559 DOI: 10.1093/plcell/koad091] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 03/03/2023] [Accepted: 03/07/2023] [Indexed: 05/30/2023]
Abstract
Besides regulating splicing, the conserved spliceosome component SmD1 (Small nuclear ribonucleoprotein D1)b promotes posttranscriptional silencing of sense transgenes (S-PTGS [post-transcriptional genesilencing]). Here, we show that the conserved spliceosome component PRP39 (Pre-mRNA-processing factor 39)a also plays a role in S-PTGS in Arabidopsis thaliana. However, PRP39a and SmD1b actions appear distinct in both splicing and S-PTGS. Indeed, RNAseq-based analysis of expression level and alternative splicing in prp39a and smd1b mutants identified different sets of deregulated transcripts and noncoding RNAs. Moreover, double mutant analyses involving prp39a or smd1b and RNA quality control (RQC) mutants revealed distinct genetic interactions for SmD1b and PRP39a with nuclear RQC machineries, suggesting nonredundant roles in the RQC/PTGS interplay. Supporting this hypothesis, a prp39a smd1b double mutant exhibited enhanced suppression of S-PTGS compared to the single mutants. Because the prp39a and smd1b mutants (i) showed no major changes in the expression of PTGS or RQC components or in small RNA production and (ii) do not alter PTGS triggered by inverted-repeat transgenes directly producing dsRNA (IR-PTGS), PRP39a, and SmD1b appear to synergistically promote a step specific to S-PTGS. We propose that, independently from their specific roles in splicing, PRP39a and SmD1b limit 3'-to-5' and/or 5'-to-3' degradation of transgene-derived aberrant RNAs in the nucleus, thus favoring the export of aberrant RNAs to the cytoplasm where their conversion into double-stranded RNA (dsRNA) initiates S-PTGS.
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Affiliation(s)
- Jérémie Bazin
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRAE, Universités Paris-Sud, Evry, Paris-Diderot, Sorbonne Paris-Cité, Paris-Saclay, Bâtiment 630, 91405 Orsay, France
| | - Emilie Elvira-Matelot
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Thomas Blein
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRAE, Universités Paris-Sud, Evry, Paris-Diderot, Sorbonne Paris-Cité, Paris-Saclay, Bâtiment 630, 91405 Orsay, France
| | - Vincent Jauvion
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Nathalie Bouteiller
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Jun Cao
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany
| | - Martin D Crespi
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRAE, Universités Paris-Sud, Evry, Paris-Diderot, Sorbonne Paris-Cité, Paris-Saclay, Bâtiment 630, 91405 Orsay, France
| | - Hervé Vaucheret
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
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4
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de Felippes FF, Waterhouse PM. Plant terminators: the unsung heroes of gene expression. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:2239-2250. [PMID: 36477559 PMCID: PMC10082929 DOI: 10.1093/jxb/erac467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/25/2022] [Indexed: 06/06/2023]
Abstract
To be properly expressed, genes need to be accompanied by a terminator, a region downstream of the coding sequence that contains the information necessary for the maturation of the mRNA 3' end. The main event in this process is the addition of a poly(A) tail at the 3' end of the new transcript, a critical step in mRNA biology that has important consequences for the expression of genes. Here, we review the mechanism leading to cleavage and polyadenylation of newly transcribed mRNAs and how this process can affect the final levels of gene expression. We give special attention to an aspect often overlooked, the effect that different terminators can have on the expression of genes. We also discuss some exciting findings connecting the choice of terminator to the biogenesis of small RNAs, which are a central part of one of the most important mechanisms of regulation of gene expression in plants.
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Affiliation(s)
| | - Peter M Waterhouse
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), Brisbane, QLD, Australia
- ARC Centre of Excellence for Plant Success in Nature & Agriculture, QUT, Brisbane, QLD, Australia
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5
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Vaucheret H. Epigenetic management of self and non-self: lessons from 40 years of transgenic plants. C R Biol 2023; 345:149-174. [PMID: 36847123 DOI: 10.5802/crbiol.96] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 12/02/2022]
Abstract
Plant varieties exhibiting unstable or variegated phenotypes, or showing virus recovery have long remained a mystery. It is only with the development of transgenic plants 40 years ago that the epigenetic features underlying these phenomena were elucidated. Indeed, the study of transgenic plants that did not express the introduced sequences revealed that transgene loci sometimes undergo transcriptional gene silencing (TGS) or post-transcriptional gene silencing (PTGS) by activating epigenetic defenses that naturally control transposable elements, duplicated genes or viruses. Even when they do not trigger TGS or PTGS spontaneously, stably expressed transgenes driven by viral promoters set apart from endogenous genes in their epigenetic regulation. As a result, transgenes driven by viral promoters are capable of undergoing systemic PTGS throughout the plant, whereas endogenous genes can only undergo local PTGS in cells where RNA quality control is impaired. Together, these results indicate that the host genome distinguishes self from non-self at the epigenetic level, allowing PTGS to eliminate non-self, and preventing PTGS to become systemic and kill the plant when it is locally activated against deregulated self.
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6
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Sehki H, Yu A, Elmayan T, Vaucheret H. TYMV and TRV infect Arabidopsis thaliana by expressing weak suppressors of RNA silencing and inducing host RNASE THREE LIKE1. PLoS Pathog 2023; 19:e1010482. [PMID: 36696453 PMCID: PMC9901757 DOI: 10.1371/journal.ppat.1010482] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 02/06/2023] [Accepted: 01/10/2023] [Indexed: 01/26/2023] Open
Abstract
Post-Transcriptional Gene Silencing (PTGS) is a defense mechanism that targets invading nucleic acids of endogenous (transposons) or exogenous (pathogens, transgenes) origins. During plant infection by viruses, virus-derived primary siRNAs target viral RNAs, resulting in both destruction of single-stranded viral RNAs (execution step) and production of secondary siRNAs (amplification step), which maximizes the plant defense. As a counter-defense, viruses express proteins referred to as Viral Suppressor of RNA silencing (VSR). Some viruses express VSRs that totally inhibit PTGS, whereas other viruses express VSRs that have limited effect. Here we show that infection with the Turnip yellow mosaic virus (TYMV) is enhanced in Arabidopsis ago1, ago2 and dcl4 mutants, which are impaired in the execution of PTGS, but not in dcl2, rdr1 and rdr6 mutants, which are impaired in the amplification of PTGS. Consistently, we show that the TYMV VSR P69 localizes in siRNA-bodies, which are the site of production of secondary siRNAs, and limits PTGS amplification. Moreover, TYMV induces the production of the host enzyme RNASE THREE-LIKE 1 (RTL1) to further reduce siRNA accumulation. Infection with the Tobacco rattle virus (TRV), which also encodes a VSR limiting PTGS amplification, induces RTL1 as well to reduce siRNA accumulation and promote infection. Together, these results suggest that RTL1 could be considered as a host susceptibility gene that is induced by viruses as a strategy to further limit the plant PTGS defense when VSRs are insufficient.
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Affiliation(s)
- Hayat Sehki
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
- Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Agnès Yu
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Taline Elmayan
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
- * E-mail:
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7
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Jay F, Brioudes F, Voinnet O. A contemporary reassessment of the enhanced transient expression system based on the tombusviral silencing suppressor protein P19. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 113:186-204. [PMID: 36403224 PMCID: PMC10107623 DOI: 10.1111/tpj.16032] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/27/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
Transient transgenic expression accelerates pharming and facilitates protein studies in plants. One embodiment of the approach involves leaf infiltration of Agrobacterium strains whose T-DNA is engineered with the gene(s) of interest. However, gene expression during 'agro-infiltration' is intrinsically and universally impeded by the onset of post-transcriptional gene silencing (PTGS). Nearly 20 years ago, a simple method was developed, whereby co-expression of the tombusvirus-encoded P19 protein suppresses PTGS and thus enhances transient gene expression. Yet, how PTGS is activated and suppressed by P19 during the process has remained unclear to date. Here, we address these intertwined questions in a manner also rationalizing how vastly increased protein yields are achieved using a minimal viral replicon as a transient gene expression vector. We also explore, in side-by-side analyses, why some proteins do not accumulate to the expected high levels in the assay, despite vastly increased mRNA levels. We validate that enhanced co-expression of multiple constructs is achieved within the same transformed cells, and illustrate how the P19 system allows rapid protein purification for optimized downstream in vitro applications. Finally, we assess the suitability of the P19 system for subcellular localization studies - an originally unanticipated, yet increasingly popular application - and uncover shortcomings of this specific implement. In revisiting the P19 system using contemporary knowledge, this study sheds light onto its hitherto poorly understood mechanisms while further illustrating its versatility but also some of its limits.
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Affiliation(s)
- Florence Jay
- Department of BiologySwiss Federal Institute of Technology (ETH‐Zürich)Universitätstrasse 28092ZürichSwitzerland
| | - Florian Brioudes
- Department of BiologySwiss Federal Institute of Technology (ETH‐Zürich)Universitätstrasse 28092ZürichSwitzerland
| | - Olivier Voinnet
- Department of BiologySwiss Federal Institute of Technology (ETH‐Zürich)Universitätstrasse 28092ZürichSwitzerland
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8
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Hoffmann G, Mahboubi A, Bente H, Garcia D, Hanson J, Hafrén A. Arabidopsis RNA processing body components LSM1 and DCP5 aid in the evasion of translational repression during Cauliflower mosaic virus infection. THE PLANT CELL 2022; 34:3128-3147. [PMID: 35511183 PMCID: PMC9338796 DOI: 10.1093/plcell/koac132] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/24/2022] [Indexed: 06/14/2023]
Abstract
Viral infections impose extraordinary RNA stress, triggering cellular RNA surveillance pathways such as RNA decapping, nonsense-mediated decay, and RNA silencing. Viruses need to maneuver among these pathways to establish infection and succeed in producing high amounts of viral proteins. Processing bodies (PBs) are integral to RNA triage in eukaryotic cells, with several distinct RNA quality control pathways converging for selective RNA regulation. In this study, we investigated the role of Arabidopsis thaliana PBs during Cauliflower mosaic virus (CaMV) infection. We found that several PB components are co-opted into viral factories that support virus multiplication. This pro-viral role was not associated with RNA decay pathways but instead, we established that PB components are helpers in viral RNA translation. While CaMV is normally resilient to RNA silencing, dysfunctions in PB components expose the virus to this pathway, which is similar to previous observations for transgenes. Transgenes, however, undergo RNA quality control-dependent RNA degradation and transcriptional silencing, whereas CaMV RNA remains stable but becomes translationally repressed through decreased ribosome association, revealing a unique dependence among PBs, RNA silencing, and translational repression. Together, our study shows that PB components are co-opted by the virus to maintain efficient translation, a mechanism not associated with canonical PB functions.
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Affiliation(s)
- Gesa Hoffmann
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala 75007, Sweden
- Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Amir Mahboubi
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå, Sweden
| | - Heinrich Bente
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala 75007, Sweden
- Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Damien Garcia
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Johannes Hanson
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå, Sweden
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9
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de Felippes FF, Shand K, Waterhouse PM. Identification of a Transferrable Terminator Element That Inhibits Small RNA Production and Improves Transgene Expression Levels. FRONTIERS IN PLANT SCIENCE 2022; 13:877793. [PMID: 35651775 PMCID: PMC9149433 DOI: 10.3389/fpls.2022.877793] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/27/2022] [Indexed: 06/06/2023]
Abstract
The role of terminators is more commonly associated with the polyadenylation and 3' end formation of new transcripts. Recent evidence, however, suggests that this regulatory region can have a dramatic impact on gene expression. Nonetheless, little is known about the molecular mechanisms leading to the improvements associated with terminator usage in plants and the different elements in a plant terminator. Here, we identified an element in the Arabidopsis HSP18.2 terminator (tHSP) to be essential for the high level of expression seen for transgenes under the regulation of this terminator. Our molecular analyses suggest that this newly identified sequence acts to improve transcription termination, leading to fewer read-through events and decreased amounts of small RNAs originating from the transgene. Besides protecting against silencing, the tHSP-derived sequence positively impacts splicing efficiency, helping to promote gene expression. Moreover, we show that this sequence can be used to generate chimeric terminators with enhanced efficiency, resulting in stronger transgene expression and significantly expanding the availability of efficient terminators that can be part of good expression systems. Thus, our data make an important contribution toward a better understanding of plant terminators, with the identification of a new element that has a direct impact on gene expression, and at the same time, creates new possibilities to modulate gene expression via the manipulation of 3' regulatory regions.
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Affiliation(s)
- Felipe Fenselau de Felippes
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Research Council (ARC) Centre of Excellence for Plant Success in Nature and Agriculture, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kylie Shand
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
| | - Peter M. Waterhouse
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Research Council (ARC) Centre of Excellence for Plant Success in Nature and Agriculture, Queensland University of Technology, Brisbane, QLD, Australia
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10
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Jin J, She Y, Qiu P, Lin W, Zhang W, Zhang J, Wu Z, Du Z. The cap-snatching frequency of a plant bunyavirus from nonsense mRNAs is low but is increased by silencing of UPF1 or SMG7. MOLECULAR PLANT PATHOLOGY 2022; 23:576-582. [PMID: 34954877 PMCID: PMC8916216 DOI: 10.1111/mpp.13179] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/13/2021] [Accepted: 12/13/2021] [Indexed: 06/02/2023]
Abstract
Bunyaviruses cleave host cellular mRNAs to acquire cap structures for their own mRNAs in a process called cap-snatching. How bunyaviruses interact with cellular mRNA surveillance pathways such as nonsense-mediated decay (NMD) during cap-snatching remains poorly understood, especially in plants. Rice stripe virus (RSV) is a plant bunyavirus threatening rice production in East Asia. Here, with a newly developed system allowing us to present defined mRNAs to RSV in Nicotiana benthamiana, we found that the frequency of RSV to target nonsense mRNAs (nsRNAs) during cap-snatching was much lower than its frequency to target normal mRNAs. The frequency of RSV to target nsRNAs was increased by virus-induced gene silencing of UPF1 or SMG7, each encoding a protein component involved in early steps of NMD (in an rdr6 RNAi background). Coincidently, RSV accumulation was increased in the UPF1- or SMG7-silenced plants. These data indicated that the frequency of RSV to target nsRNAs during cap-snatching is restricted by NMD. By restricting the frequency of RSV to target nsRNAs, NMD may impose a constraint to the overall cap-snatching efficiency of RSV. Besides a deeper understanding for the cap-snatching of RSV, these findings point to a novel role of NMD in plant-bunyavirus interactions.
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Affiliation(s)
- Jing Jin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFuzhouChina
| | - Yuanyuan She
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFuzhouChina
| | - Ping Qiu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFuzhouChina
| | - Wenzhong Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFuzhouChina
| | - Wenwen Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFuzhouChina
| | - Jie Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFuzhouChina
| | - Zujian Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFuzhouChina
- Plant Virus Research InstituteFujian Agricultural and Forestry UniversityFuzhouChina
| | - Zhenguo Du
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFuzhouChina
- Plant Virus Research InstituteFujian Agricultural and Forestry UniversityFuzhouChina
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11
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Lange H, Gagliardi D. Catalytic activities, molecular connections, and biological functions of plant RNA exosome complexes. THE PLANT CELL 2022; 34:967-988. [PMID: 34954803 PMCID: PMC8894942 DOI: 10.1093/plcell/koab310] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/16/2021] [Indexed: 05/08/2023]
Abstract
RNA exosome complexes provide the main 3'-5'-exoribonuclease activities in eukaryotic cells and contribute to the maturation and degradation of virtually all types of RNA. RNA exosomes consist of a conserved core complex that associates with exoribonucleases and with multimeric cofactors that recruit the enzyme to its RNA targets. Despite an overall high level of structural and functional conservation, the enzymatic activities and compositions of exosome complexes and their cofactor modules differ among eukaryotes. This review highlights unique features of plant exosome complexes, such as the phosphorolytic activity of the core complex, and discusses the exosome cofactors that operate in plants and are dedicated to the maturation of ribosomal RNA, the elimination of spurious, misprocessed, and superfluous transcripts, or the removal of mRNAs cleaved by the RNA-induced silencing complex and other mRNAs prone to undergo silencing.
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Affiliation(s)
- Heike Lange
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
- Author for correspondence:
| | - Dominique Gagliardi
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
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12
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Krzyszton M, Kufel J. Analysis of mRNA-derived siRNAs in mutants of mRNA maturation and surveillance pathways in Arabidopsis thaliana. Sci Rep 2022; 12:1474. [PMID: 35087200 PMCID: PMC8795450 DOI: 10.1038/s41598-022-05574-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/14/2022] [Indexed: 02/05/2023] Open
Abstract
Defects in RNA maturation and RNA decay factors may generate substrates for the RNA interference machinery. This phenomenon was observed in plants where mutations in some RNA-related factors lead to the production of RNA-quality control small interfering RNAs and several mutants show enhanced silencing of reporter transgenes. To assess the potential of RNAi activation on endogenous transcripts, we sequenced small RNAs from a set of Arabidopsis thaliana mutants with defects in various RNA metabolism pathways. We observed a global production of siRNAs caused by inefficient pre-mRNA cleavage and polyadenylation leading to read-through transcription into downstream antisense genes. In addition, in the lsm1a lsm1b double mutant, we identified NIA1, SMXL5, and several miRNA-targeted mRNAs as producing siRNAs, a group of transcripts suggested being especially sensitive to deficiencies in RNA metabolism. However, in most cases, RNA metabolism perturbations do not lead to the widespread production of siRNA derived from mRNA molecules. This observation is contrary to multiple studies based on reporter transgenes and suggests that only a very high accumulation of defective mRNA species caused by specific mutations or substantial RNA processing defects trigger RNAi pathways.
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Affiliation(s)
- Michal Krzyszton
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland.
| | - Joanna Kufel
- Faculty of Biology, Institute of Genetics and Biotechnology, University of Warsaw, Pawinskiego 5a, 02-106, Warsaw, Poland.
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13
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Vigh ML, Bressendorff S, Thieffry A, Arribas-Hernández L, Brodersen P. Nuclear and cytoplasmic RNA exosomes and PELOTA1 prevent miRNA-induced secondary siRNA production in Arabidopsis. Nucleic Acids Res 2022; 50:1396-1415. [PMID: 35037064 PMCID: PMC8860578 DOI: 10.1093/nar/gkab1289] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 12/13/2021] [Accepted: 01/03/2022] [Indexed: 11/14/2022] Open
Abstract
Amplification of short interfering RNA (siRNAs) via RNA-dependent RNA polymerases (RdRPs) is of fundamental importance in RNA silencing. Plant microRNA (miRNA) action generally does not involve engagement of RdRPs, in part thanks to a poorly understood activity of the cytoplasmic exosome adaptor SKI2. Here, we show that inactivation of the exosome subunit RRP45B and SKI2 results in similar patterns of miRNA-induced siRNA production. Furthermore, loss of the nuclear exosome adaptor HEN2 leads to secondary siRNA production from miRNA targets largely distinct from those producing siRNAs in ski2. Importantly, mutation of the Release Factor paralogue PELOTA1 required for subunit dissociation of stalled ribosomes causes siRNA production from miRNA targets overlapping with, but distinct from, those affected in ski2 and rrp45b mutants. We also show that in exosome mutants, miRNA targets can be sorted into producers and non-producers of illicit secondary siRNAs based on trigger miRNA levels and miRNA:target affinity rather than on presence of 5′-cleavage fragments. We propose that stalled RNA-Induced Silencing Complex (RISC) and ribosomes, but not mRNA cleavage fragments released from RISC, trigger siRNA production, and that the exosome limits siRNA amplification by reducing RISC dwell time on miRNA target mRNAs while PELOTA1 does so by reducing ribosome stalling.
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Affiliation(s)
- Maria L Vigh
- University of Copenhagen, Copenhagen Plant Science Center, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark
| | - Simon Bressendorff
- University of Copenhagen, Copenhagen Plant Science Center, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark
| | - Axel Thieffry
- University of Copenhagen, Copenhagen Plant Science Center, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark
| | - Laura Arribas-Hernández
- University of Copenhagen, Copenhagen Plant Science Center, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark
| | - Peter Brodersen
- University of Copenhagen, Copenhagen Plant Science Center, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark
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14
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Oberlin S, Rajeswaran R, Trasser M, Barragán-Borrero V, Schon MA, Plotnikova A, Loncsek L, Nodine MD, Marí-Ordóñez A, Voinnet O. Innate, translation-dependent silencing of an invasive transposon in Arabidopsis. EMBO Rep 2021; 23:e53400. [PMID: 34931432 PMCID: PMC8892269 DOI: 10.15252/embr.202153400] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022] Open
Abstract
Co‐evolution between hosts’ and parasites’ genomes shapes diverse pathways of acquired immunity based on silencing small (s)RNAs. In plants, sRNAs cause heterochromatinization, sequence degeneration, and, ultimately, loss of autonomy of most transposable elements (TEs). Recognition of newly invasive plant TEs, by contrast, involves an innate antiviral‐like silencing response. To investigate this response’s activation, we studied the single‐copy element EVADÉ (EVD), one of few representatives of the large Ty1/Copia family able to proliferate in Arabidopsis when epigenetically reactivated. In Ty1/Copia elements, a short subgenomic mRNA (shGAG) provides the necessary excess of structural GAG protein over the catalytic components encoded by the full‐length genomic flGAG‐POL. We show here that the predominant cytosolic distribution of shGAG strongly favors its translation over mostly nuclear flGAG‐POL. During this process, an unusually intense ribosomal stalling event coincides with mRNA breakage yielding unconventional 5’OH RNA fragments that evade RNA quality control. The starting point of sRNA production by RNA‐DEPENDENT‐RNA‐POLYMERASE‐6 (RDR6), exclusively on shGAG, occurs precisely at this breakage point. This hitherto‐unrecognized “translation‐dependent silencing” (TdS) is independent of codon usage or GC content and is not observed on TE remnants populating the Arabidopsis genome, consistent with their poor association, if any, with polysomes. We propose that TdS forms a primal defense against EVD de novo invasions that underlies its associated sRNA pattern.
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Affiliation(s)
- Stefan Oberlin
- Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Rajendran Rajeswaran
- Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Marieke Trasser
- Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, Austria.,Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Verónica Barragán-Borrero
- Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.,Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, Austria
| | - Michael A Schon
- Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, Austria
| | - Alexandra Plotnikova
- Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, Austria
| | - Lukas Loncsek
- Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, Austria
| | - Michael D Nodine
- Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, Austria.,Laboratory of Molecular Biology, Wageningen University, Wageningen, The Netherlands
| | - Arturo Marí-Ordóñez
- Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.,Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences, Vienna, Austria
| | - Olivier Voinnet
- Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
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15
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The diversity of post-transcriptional gene silencing mediated by small silencing RNAs in plants. Essays Biochem 2021; 64:919-930. [PMID: 32885814 DOI: 10.1042/ebc20200006] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/11/2020] [Accepted: 08/14/2020] [Indexed: 12/31/2022]
Abstract
In plants, post-transcriptional gene silencing (PTGS) tightly regulates development, maintains genome stability and protects plant against foreign genes. PTGS can be triggered by virus infection, transgene, and endogenous transcript, thus commonly serves as an RNA-based immune mechanism. Accordingly, based on the initiating factors, PTGS can be divided into viral-PTGS, transgene-PTGS, and endo-gene-PTGS. Unlike the intensely expressed invading transgenes and viral genes that frequently undergo PTGS, most endogenous genes do not trigger PTGS, except for a few that can produce endogenous small RNAs (sRNAs), including microRNA (miRNA) and small interfering RNA (siRNA). Different lengths of miRNA and siRNA, mainly 21-, 22- or 24-nucleotides (nt) exert diverse functions, ranging from target mRNA degradation, translational inhibition, or DNA methylation and chromatin modifications. The abundant 21-nt miRNA or siRNA, processed by RNase-III enzyme DICER-LIKE 1 (DCL1) and DCL4, respectively, have been well studied in the PTGS pathways. By contrast, the scarceness of endogenous 22-nt sRNAs that are primarily processed by DCL2 limits their research, although a few encouraging studies have been reported recently. Therefore, we review here our current understanding of diverse PTGS pathways triggered by a variety of sRNAs and summarize the distinct features of the 22-nt sRNA mediated PTGS.
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16
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Hung YH, Slotkin RK. The initiation of RNA interference (RNAi) in plants. CURRENT OPINION IN PLANT BIOLOGY 2021; 61:102014. [PMID: 33657510 DOI: 10.1016/j.pbi.2021.102014] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/19/2021] [Accepted: 01/24/2021] [Indexed: 05/15/2023]
Abstract
When an mRNA enters into the RNA degradation pathway called RNA interference (RNAi), it is cleaved into small interfering RNAs (siRNAs) that then target complementary mRNAs for destruction. The consequence of entry into RNAi is mRNA degradation, post-transcriptional silencing and in some cases transcriptional silencing. RNAi functions as a defense against transposable element and virus activity, and in plants, RNAi additionally plays a role in development by regulating some genes. However, it is unknown how specific transcripts are selected for RNAi, and how most genic mRNAs steer clear. This Current Opinion article explores the key question of how RNAs are selected for entry into RNAi, and proposes models that enable the cell to distinguish between transcripts to translate versus destroy.
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Affiliation(s)
- Yu-Hung Hung
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - R Keith Slotkin
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA; Division of Biological Sciences, University of Missouri-Columbia, 65211, USA.
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17
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Auth M, Nyikó T, Auber A, Silhavy D. The role of RST1 and RIPR proteins in plant RNA quality control systems. PLANT MOLECULAR BIOLOGY 2021; 106:271-284. [PMID: 33864582 PMCID: PMC8116306 DOI: 10.1007/s11103-021-01145-9] [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: 11/19/2020] [Accepted: 03/22/2021] [Indexed: 05/03/2023]
Abstract
To keep mRNA homeostasis, the RNA degradation, quality control and silencing systems should act in balance in plants. Degradation of normal mRNA starts with deadenylation, then deadenylated transcripts are degraded by the SKI-exosome 3'-5' and/or XRN4 5'-3' exonucleases. RNA quality control systems identify and decay different aberrant transcripts. RNA silencing degrades double-stranded transcripts and homologous mRNAs. It also targets aberrant and silencing prone transcripts. The SKI-exosome is essential for mRNA homeostasis, it functions in normal mRNA degradation and different RNA quality control systems, and in its absence silencing targets normal transcripts. It is highly conserved in eukaryotes, thus recent reports that the plant SKI-exosome is associated with RST1 and RIPR proteins and that, they are required for SKI-exosome-mediated decay of silencing prone transcripts were unexpected. To clarify whether RST1 and RIPR are essential for all SKI-exosome functions or only for the elimination of silencing prone transcripts, degradation of different reporter transcripts was studied in RST1 and RIPR inactivated Nicotiana benthamiana plants. As RST1 and RIPR, like the SKI-exosome, were essential for Non-stop and No-go decay quality control systems, and for RNA silencing- and minimum ORF-mediated decay, we propose that RST1 and RIPR are essential components of plant SKI-exosome supercomplex.
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Affiliation(s)
- Mariann Auth
- Biological Research Centre, Institute of Plant Biology, ELKH, Temesvári krt 62, 6726, Szeged, Hungary
- Agricultural Biotechnology Institute, Department of Genetics, NARIC, Gödöllő, Hungary
| | - Tünde Nyikó
- Agricultural Biotechnology Institute, Department of Genetics, NARIC, Gödöllő, Hungary
| | - Andor Auber
- Agricultural Biotechnology Institute, Department of Genetics, NARIC, Gödöllő, Hungary
| | - Dániel Silhavy
- Biological Research Centre, Institute of Plant Biology, ELKH, Temesvári krt 62, 6726, Szeged, Hungary.
- Agricultural Biotechnology Institute, Department of Genetics, NARIC, Gödöllő, Hungary.
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18
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Butel N, Yu A, Le Masson I, Borges F, Elmayan T, Taochy C, Gursanscky NR, Cao J, Bi S, Sawyer A, Carroll BJ, Vaucheret H. Contrasting epigenetic control of transgenes and endogenous genes promotes post-transcriptional transgene silencing in Arabidopsis. Nat Commun 2021; 12:2787. [PMID: 33986281 PMCID: PMC8119426 DOI: 10.1038/s41467-021-22995-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 04/06/2021] [Indexed: 11/20/2022] Open
Abstract
Transgenes that are stably expressed in plant genomes over many generations could be assumed to behave epigenetically the same as endogenous genes. Here, we report that whereas the histone H3K9me2 demethylase IBM1, but not the histone H3K4me3 demethylase JMJ14, counteracts DNA methylation of Arabidopsis endogenous genes, JMJ14, but not IBM1, counteracts DNA methylation of expressed transgenes. Additionally, JMJ14-mediated specific attenuation of transgene DNA methylation enhances the production of aberrant RNAs that readily induce systemic post-transcriptional transgene silencing (PTGS). Thus, the JMJ14 chromatin modifying complex maintains expressed transgenes in a probationary state of susceptibility to PTGS, suggesting that the host plant genome does not immediately accept expressed transgenes as being epigenetically the same as endogenous genes. Accumulating evidences point to a discrepancy in the epigenetic behaviour of transgenes and endogenous genes. Here, via characterization of mutants impaired in histone demethylases JMJ14 and IBM1, the authors show that transgenes and endogenous genes are regulated by different epigenetic mechanisms in Arabidopsis.
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Affiliation(s)
- Nicolas Butel
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France.,Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Agnès Yu
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Ivan Le Masson
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Filipe Borges
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Taline Elmayan
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Christelle Taochy
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Nial R Gursanscky
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Jiangling Cao
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Shengnan Bi
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Anne Sawyer
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.,Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia
| | - Bernard J Carroll
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France.
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19
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Scheer H, de Almeida C, Ferrier E, Simonnot Q, Poirier L, Pflieger D, Sement FM, Koechler S, Piermaria C, Krawczyk P, Mroczek S, Chicher J, Kuhn L, Dziembowski A, Hammann P, Zuber H, Gagliardi D. The TUTase URT1 connects decapping activators and prevents the accumulation of excessively deadenylated mRNAs to avoid siRNA biogenesis. Nat Commun 2021; 12:1298. [PMID: 33637717 PMCID: PMC7910438 DOI: 10.1038/s41467-021-21382-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 01/19/2021] [Indexed: 12/15/2022] Open
Abstract
Uridylation is a widespread modification destabilizing eukaryotic mRNAs. Yet, molecular mechanisms underlying TUTase-mediated mRNA degradation remain mostly unresolved. Here, we report that the Arabidopsis TUTase URT1 participates in a molecular network connecting several translational repressors/decapping activators. URT1 directly interacts with DECAPPING 5 (DCP5), the Arabidopsis ortholog of human LSM14 and yeast Scd6, and this interaction connects URT1 to additional decay factors like DDX6/Dhh1-like RNA helicases. Nanopore direct RNA sequencing reveals a global role of URT1 in shaping poly(A) tail length, notably by preventing the accumulation of excessively deadenylated mRNAs. Based on in vitro and in planta data, we propose a model that explains how URT1 could reduce the accumulation of oligo(A)-tailed mRNAs both by favoring their degradation and because 3' terminal uridines intrinsically hinder deadenylation. Importantly, preventing the accumulation of excessively deadenylated mRNAs avoids the biogenesis of illegitimate siRNAs that silence endogenous mRNAs and perturb Arabidopsis growth and development.
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Affiliation(s)
- Hélène Scheer
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Caroline de Almeida
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Emilie Ferrier
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Quentin Simonnot
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Laure Poirier
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - David Pflieger
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - François M Sement
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Sandrine Koechler
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Christina Piermaria
- Plateforme Protéomique Strasbourg Esplanade du CNRS, Université de Strasbourg, Strasbourg, France
| | - Paweł Krawczyk
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
- Faculty of Biology, Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | - Seweryn Mroczek
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
- Faculty of Biology, Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | - Johana Chicher
- Plateforme Protéomique Strasbourg Esplanade du CNRS, Université de Strasbourg, Strasbourg, France
| | - Lauriane Kuhn
- Plateforme Protéomique Strasbourg Esplanade du CNRS, Université de Strasbourg, Strasbourg, France
| | - Andrzej Dziembowski
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
- Faculty of Biology, Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | - Philippe Hammann
- Plateforme Protéomique Strasbourg Esplanade du CNRS, Université de Strasbourg, Strasbourg, France
| | - Hélène Zuber
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France.
| | - Dominique Gagliardi
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France.
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20
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Freire MÁ. Viral silencing suppressors and cellular proteins partner with plant RRP6-like exoribonucleases. Virus Genes 2020; 56:621-631. [PMID: 32519287 DOI: 10.1007/s11262-020-01775-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/02/2020] [Indexed: 10/24/2022]
Abstract
RNA silencing and RNA decay are functionally interlaced, regulate gene expression and play a pivotal role in antiviral responses. As a counter-defensive strategy, many plant and mammalian viruses encode suppressors which interfere with both mechanisms. However, the protein interactions that connect these pathways remain elusive. Previous work reported that RNA silencing suppressors from different potyviruses, together with translation initiation factors EIF(iso)4E, interacted with the C-terminal region of the tobacco exoribonuclease RRP6-like 2, a component of the RNA decay exosome complex. Here, we investigate whether other viral silencing suppressors and cellular proteins might also bind RRP6-like exoribonucleases. A candidate search approach based on yeast two-hybrid protein interaction assays showed that three other unrelated viral suppressors, two from plant viruses and one from a mammalian virus, bound the C-terminus of the tobacco RRP6-like 2, the full-length of the Arabidopsis RRP6L1 protein and its C-terminal region. In addition, RRP6-like proteins were found to interact with members of the cellular double-stranded RNA-binding protein (DRB) family involved in RNA silencing. The C-terminal regions of RRP6L proteins are engaged in homotypic and heterotypic interactions and were predicted to be disordered. Collectively, these results suggest a protein interaction network that connects components of RNA decay and RNA silencing that is targeted by viral silencing suppressors.
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Affiliation(s)
- Miguel Ángel Freire
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET, Universidad Nacional de Córdoba (UNC), Av. Vélez Sarsfield 299, CC 495, 5000, Córdoba, Argentina.
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21
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Zhang Y, Wu X, Yuan L. Distinct non-coding RNAs confer root-dependent sense transgene-induced post-transcriptional gene silencing and nitrogen-dependent post-transcriptional regulation to AtAMT1;1 transcripts in Arabidopsis roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 102:823-837. [PMID: 31901180 DOI: 10.1111/tpj.14667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/19/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
High-affinity ammonium uptake in roots mediate by AMT1-type ammonium transporters, which are tightly controlled at multiple regulatory levels for adapting various nitrogen availability. For Arabidopsis AtAMT1;1 gene, in addition to the transcriptional and post-translational controls, an organ-dependent and N-dependent post-transcriptional regulation was suggested as an additional regulatory step for fine tuning ammonium uptake, but the underlying mechanisms remain to be elucidated. Here, we showed that degradation of AtAMT1;1 transcript in roots of Pro35s:AtAMT1;1-transformed atamt1;1-1 Arabidopsis plants resulted from RDR6-dependent sense transgene-induced post-transcriptional gene silencing (S-PTGS). The siRNAs for S-PTGS may derive from the aberrant RNA, of which the production was co-determined by sequence feature and excessive expression of AtAMT1;1. Switching to the expression of AtAMT1;1 driven by ProAtUBQ10 or of AtAMT1;1 mutated at two siRNA-targeted hotspots reduced AtAMT1;1-specific siRNAs and overcame S-PTGS in roots. In roots of these lines, however, the steady-state transcript levels of AtAMT1;1 still significantly decreased under conditions of N-sufficiency compared with N-deficiency, confirming a N-dependent post-transcriptional regulatory manner. A crucial role of the 207-bp 3'-end sequence of AtAMT1;1 was further demonstrated by N-dependent accumulation of chimeric-AtAMT1;1 transcript in T-DNA insertion lines and of GFP-tagged chimeric-AtAMT1;1 transcript in transgenic lines. A novel non-coding RNA (ncRNA), which was highly abundant in N-sufficient roots, may target the above-identified 3'-end region for the degrading AtAMT1;1 transcript. This degradation could be prevented by a mutation on the AtAMT1;1 transcript at a potential cleavage site (+1458). These results suggested two distinct mechanisms of regulating AtAMT1;1 mRNA turnover by ncRNA for strictly control of ammonium uptake in roots.
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Affiliation(s)
- Yongjian Zhang
- Key Laboratory of Plant-Soil Interaction, MOE, College of Resources and Environmental Sciences, China Agricultural University, 100193, Beijing, China
| | - Xiangyu Wu
- Key Laboratory of Plant-Soil Interaction, MOE, College of Resources and Environmental Sciences, China Agricultural University, 100193, Beijing, China
| | - Lixing Yuan
- Key Laboratory of Plant-Soil Interaction, MOE, College of Resources and Environmental Sciences, China Agricultural University, 100193, Beijing, China
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22
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Zhang ZJ, Gao Q, Fang XD, Ding ZH, Gao DM, Xu WY, Cao Q, Qiao JH, Yang YZ, Han C, Wang Y, Yuan X, Li D, Wang XB. CCR4, a RNA decay factor, is hijacked by a plant cytorhabdovirus phosphoprotein to facilitate virus replication. eLife 2020; 9:53753. [PMID: 32207684 PMCID: PMC7105381 DOI: 10.7554/elife.53753] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/21/2020] [Indexed: 12/14/2022] Open
Abstract
Carbon catabolite repression 4 (CCR4) is a conserved mRNA deadenylase regulating posttranscriptional gene expression. However, regulation of CCR4 in virus infections is less understood. Here, we characterized a pro-viral role of CCR4 in replication of a plant cytorhabdovirus, Barley yellow striate mosaic virus (BYSMV). The barley (Hordeum vulgare) CCR4 protein (HvCCR4) was identified to interact with the BYSMV phosphoprotein (P). The BYSMV P protein recruited HvCCR4 from processing bodies (PBs) into viroplasm-like bodies. Overexpression of HvCCR4 promoted BYSMV replication in plants. Conversely, knockdown of the small brown planthopper CCR4 inhibited viral accumulation in the insect vector. Biochemistry experiments revealed that HvCCR4 was recruited into N–RNA complexes by the BYSMV P protein and triggered turnover of N-bound cellular mRNAs, thereby releasing RNA-free N protein to bind viral genomic RNA for optimal viral replication. Our results demonstrate that the co-opted CCR4-mediated RNA decay facilitates cytorhabdovirus replication in plants and insects.
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Affiliation(s)
- Zhen-Jia Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qiang Gao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiao-Dong Fang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhi-Hang Ding
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Dong-Min Gao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Wen-Ya Xu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qing Cao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Ji-Hui Qiao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Yi-Zhou Yang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Chenggui Han
- College of Plant Protection, China Agricultural University, Beijing, China
| | - Ying Wang
- College of Plant Protection, China Agricultural University, Beijing, China
| | - Xuefeng Yuan
- Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Shandong Province Key Laboratory of Agricultural Microbiology, Tai'an, China
| | - Dawei Li
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xian-Bing Wang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
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23
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Ariel F, Lucero L, Christ A, Mammarella MF, Jegu T, Veluchamy A, Mariappan K, Latrasse D, Blein T, Liu C, Benhamed M, Crespi M. R-Loop Mediated trans Action of the APOLO Long Noncoding RNA. Mol Cell 2020; 77:1055-1065.e4. [DOI: 10.1016/j.molcel.2019.12.015] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/30/2019] [Accepted: 12/18/2019] [Indexed: 11/25/2022]
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24
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Sulkowska A, Auber A, Sikorski PJ, Silhavy DN, Auth M, Sitkiewicz E, Jean V, Merret RM, Bousquet-Antonelli CC, Kufel J. RNA Helicases from the DEA(D/H)-Box Family Contribute to Plant NMD Efficiency. PLANT & CELL PHYSIOLOGY 2020; 61:144-157. [PMID: 31560399 DOI: 10.1093/pcp/pcz186] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 09/16/2019] [Indexed: 06/10/2023]
Abstract
Nonsense-mediated mRNA decay (NMD) is a conserved eukaryotic RNA surveillance mechanism that degrades aberrant mRNAs comprising a premature translation termination codon. The adenosine triphosphate (ATP)-dependent RNA helicase up-frameshift 1 (UPF1) is a major NMD factor in all studied organisms; however, the complexity of this mechanism has not been fully characterized in plants. To identify plant NMD factors, we analyzed UPF1-interacting proteins using tandem affinity purification coupled to mass spectrometry. Canonical members of the NMD pathway were found along with numerous NMD candidate factors, including conserved DEA(D/H)-box RNA helicase homologs of human DDX3, DDX5 and DDX6, translation initiation factors, ribosomal proteins and transport factors. Our functional studies revealed that depletion of DDX3 helicases enhances the accumulation of NMD target reporter mRNAs but does not result in increased protein levels. In contrast, silencing of DDX6 group leads to decreased accumulation of the NMD substrate. The inhibitory effect of DDX6-like helicases on NMD was confirmed by transient overexpression of RH12 helicase. These results indicate that DDX3 and DDX6 helicases in plants have a direct and opposing contribution to NMD and act as functional NMD factors.
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Affiliation(s)
- Aleksandra Sulkowska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Andor Auber
- Agricultural Biotechnology Institute, Szent-Gy�rgyi 4, H-2100 G�d�llő, Hungary
| | - Pawel J Sikorski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Dï Niel Silhavy
- Agricultural Biotechnology Institute, Szent-Gy�rgyi 4, H-2100 G�d�llő, Hungary
| | - Mariann Auth
- Agricultural Biotechnology Institute, Szent-Gy�rgyi 4, H-2100 G�d�llő, Hungary
| | - Ewa Sitkiewicz
- Proteomics Laboratory, Biophysics Department, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland
| | - Viviane Jean
- UMR5096 LGDP, Universit� de Perpignan Via Domitia, UMR5096 LGDP58, Avenue Paul Alduy, 66860 Perpignan Cedex, France
- CNRS, UMR5096 LGDP, Perpignan Cedex, France
| | - Rï My Merret
- UMR5096 LGDP, Universit� de Perpignan Via Domitia, UMR5096 LGDP58, Avenue Paul Alduy, 66860 Perpignan Cedex, France
- CNRS, UMR5096 LGDP, Perpignan Cedex, France
| | - Cï Cile Bousquet-Antonelli
- UMR5096 LGDP, Universit� de Perpignan Via Domitia, UMR5096 LGDP58, Avenue Paul Alduy, 66860 Perpignan Cedex, France
- CNRS, UMR5096 LGDP, Perpignan Cedex, France
| | - Joanna Kufel
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
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25
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de Felippes FF, Waterhouse PM. The Whys and Wherefores of Transitivity in Plants. FRONTIERS IN PLANT SCIENCE 2020; 11:579376. [PMID: 32983223 PMCID: PMC7488869 DOI: 10.3389/fpls.2020.579376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 08/14/2020] [Indexed: 05/05/2023]
Abstract
Transitivity in plants is a mechanism that produces secondary small interfering RNAs (siRNAs) from a transcript targeted by primary small RNAs (sRNAs). It expands the silencing signal to additional sequences of the transcript. The process requires RNA-dependent RNA polymerases (RDRs), which convert single-stranded RNA targets into a double-stranded (ds) RNA, the precursor of siRNAs and is critical for effective and amplified responses to virus infection. It is also important for the production of endogenous secondary siRNAs, such as phased siRNAs (phasiRNAs), which regulate several genes involved in development and adaptation. Transitivity on endogenous transcripts is very specific, utilizing special primary sRNAs, such as miRNAs with unique features, and particular ARGONAUTEs. In contrast, transitivity on transgene and virus (exogenous) transcripts is more generic. This dichotomy of responses implies the existence of a mechanism that differentiates self from non-self targets. In this work, we examine the possible mechanistic process behind the dichotomy and the intriguing counter-intuitive directionality of transitive sequence-spread in plants.
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26
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Taochy C, Yu A, Bouché N, Bouteiller N, Elmayan T, Dressel U, Carroll BJ, Vaucheret H. Post-transcriptional gene silencing triggers dispensable DNA methylation in gene body in Arabidopsis. Nucleic Acids Res 2019; 47:9104-9114. [PMID: 31372641 PMCID: PMC6753489 DOI: 10.1093/nar/gkz636] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/27/2019] [Accepted: 07/26/2019] [Indexed: 11/14/2022] Open
Abstract
Spontaneous post-transcriptional silencing of sense transgenes (S-PTGS) is established in each generation and is accompanied by DNA methylation, but the pathway of PTGS-dependent DNA methylation is unknown and so is its role. Here we show that CHH and CHG methylation coincides spatially and temporally with RDR6-dependent products derived from the central and 3' regions of the coding sequence, and requires the components of the RNA-directed DNA methylation (RdDM) pathway NRPE1, DRD1 and DRM2, but not CLSY1, NRPD1, RDR2 or DCL3, suggesting that RDR6-dependent products, namely long dsRNAs and/or siRNAs, trigger PTGS-dependent DNA methylation. Nevertheless, none of these RdDM components are required to establish S-PTGS or produce a systemic silencing signal. Moreover, preventing de novo DNA methylation in non-silenced transgenic tissues grafted onto homologous silenced tissues does not inhibit the triggering of PTGS. Overall, these data indicate that gene body DNA methylation is a consequence, not a cause, of PTGS, and rule out the hypothesis that a PTGS-associated DNA methylation signal is transmitted independent of a PTGS signal.
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Affiliation(s)
- Christelle Taochy
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Agnès Yu
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Nicolas Bouché
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Nathalie Bouteiller
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Taline Elmayan
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Uwe Dressel
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Bernard J Carroll
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
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27
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Kim MH, Jeon J, Lee S, Lee JH, Gao L, Lee BH, Park JM, Kim YJ, Kwak JM. Proteasome subunit RPT2a promotes PTGS through repressing RNA quality control in Arabidopsis. NATURE PLANTS 2019; 5:1273-1282. [PMID: 31740770 DOI: 10.1038/s41477-019-0546-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 10/09/2019] [Indexed: 05/12/2023]
Abstract
RNA quality control (RQC) and post-transcriptional gene silencing (PTGS) target and degrade aberrant endogenous RNAs and foreign RNAs, contributing to homeostasis of cellular RNAs. In plants, RQC and PTGS compete for foreign and selected endogenous RNAs; however, little is known about the mechanism interconnecting the two pathways. Using a reporter system designed for monitoring PTGS, we revealed that the 26S proteasome subunit RPT2a enhances transgene PTGS by promoting the accumulation of transgene-derived short interfering RNAs without affecting their biogenesis. RPT2a physically associated with a subset of RQC components and downregulated the protein level. Overexpression of the RQC components interfered with transgene silencing, and impairment of the RQC machinery reinforced transgene PTGS attenuated by rpt2a. Overall, we demonstrate that the 26S proteasome subunit RPT2a promotes PTGS by repressing the RQC machinery to control foreign RNAs.
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Affiliation(s)
- Myung-Hee Kim
- Center for Plant Aging Research, Institute for Basic Science, Daegu, Republic of Korea
| | - Jieun Jeon
- Center for Plant Aging Research, Institute for Basic Science, Daegu, Republic of Korea
- Department of New Biology, DGIST, Daegu, Republic of Korea
| | - Seulbee Lee
- Center for Plant Aging Research, Institute for Basic Science, Daegu, Republic of Korea
| | - Jae Ho Lee
- Center for Plant Aging Research, Institute for Basic Science, Daegu, Republic of Korea
- Department of New Biology, DGIST, Daegu, Republic of Korea
| | - Lei Gao
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Byung-Hoon Lee
- Department of New Biology, DGIST, Daegu, Republic of Korea
| | - Jeong Mee Park
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Yun Ju Kim
- Center for Plant Aging Research, Institute for Basic Science, Daegu, Republic of Korea.
| | - June M Kwak
- Department of New Biology, DGIST, Daegu, Republic of Korea.
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28
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FIERY1 promotes microRNA accumulation by suppressing rRNA-derived small interfering RNAs in Arabidopsis. Nat Commun 2019; 10:4424. [PMID: 31562313 PMCID: PMC6765019 DOI: 10.1038/s41467-019-12379-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 09/06/2019] [Indexed: 01/29/2023] Open
Abstract
Plant microRNAs (miRNAs) associate with ARGONAUTE1 (AGO1) to direct post-transcriptional gene silencing and regulate numerous biological processes. Although AGO1 predominantly binds miRNAs in vivo, it also associates with endogenous small interfering RNAs (siRNAs). It is unclear whether the miRNA/siRNA balance affects miRNA activities. Here we report that FIERY1 (FRY1), which is involved in 5'-3' RNA degradation, regulates miRNA abundance and function by suppressing the biogenesis of ribosomal RNA-derived siRNAs (risiRNAs). In mutants of FRY1 and the nuclear 5'-3' exonuclease genes XRN2 and XRN3, we find that a large number of 21-nt risiRNAs are generated through an endogenous siRNA biogenesis pathway. The production of risiRNAs correlates with pre-rRNA processing defects in these mutants. We also show that these risiRNAs are loaded into AGO1, causing reduced loading of miRNAs. This study reveals a previously unknown link between rRNA processing and miRNA accumulation.
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29
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The Recovery from Sulfur Starvation Is Independent from the mRNA Degradation Initiation Enzyme PARN in Arabidopsis. PLANTS 2019; 8:plants8100380. [PMID: 31569782 PMCID: PMC6843384 DOI: 10.3390/plants8100380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/23/2019] [Accepted: 09/26/2019] [Indexed: 11/23/2022]
Abstract
When plants are exposed to sulfur limitation, they upregulate the sulfate assimilation pathway at the expense of growth-promoting measures. Upon cessation of the stress, however, protective measures are deactivated, and growth is restored. In accordance with these findings, transcripts of sulfur-deficiency marker genes are rapidly degraded when starved plants are resupplied with sulfur. Yet it remains unclear which enzymes are responsible for the degradation of transcripts during the recovery from starvation. In eukaryotes, mRNA decay is often initiated by the cleavage of poly(A) tails via deadenylases. As mutations in the poly(A) ribonuclease PARN have been linked to altered abiotic stress responses in Arabidopsis thaliana, we investigated the role of PARN in the recovery from sulfur starvation. Despite the presence of putative PARN-recruiting AU-rich elements in sulfur-responsive transcripts, sulfur-depleted PARN hypomorphic mutants were able to reset their transcriptome to pre-starvation conditions just as readily as wildtype plants. Currently, the subcellular localization of PARN is disputed, with studies reporting both nuclear and cytosolic localization. We detected PARN in cytoplasmic speckles and reconciled the diverging views in literature by identifying two PARN splice variants whose predicted localization is in agreement with those observations.
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30
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Kesarwani AK, Lee HC, Ricca PG, Sullivan G, Faiss N, Wagner G, Wunderling A, Wachter A. Multifactorial and Species-Specific Feedback Regulation of the RNA Surveillance Pathway Nonsense-Mediated Decay in Plants. PLANT & CELL PHYSIOLOGY 2019; 60:1986-1999. [PMID: 31368494 DOI: 10.1093/pcp/pcz141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 07/06/2019] [Indexed: 05/16/2023]
Abstract
Nonsense-mediated decay (NMD) is an RNA surveillance mechanism that detects aberrant transcript features and triggers degradation of erroneous as well as physiological RNAs. Originally considered to be constitutive, NMD is now recognized to be tightly controlled in response to inherent signals and diverse stresses. To gain a better understanding of NMD regulation and its functional implications, we systematically examined feedback control of the central NMD components in two dicot and one monocot species. On the basis of the analysis of transcript features, turnover rates and steady-state levels, up-frameshift (UPF) 1, UPF3 and suppressor of morphological defects on genitalia (SMG) 7, but not UPF2, are under feedback control in both dicots. In the monocot investigated in this study, only SMG7 was slightly induced upon NMD inhibition. The detection of the endogenous NMD factor proteins in Arabidopsis thaliana substantiated a negative correlation between NMD activity and SMG7 amounts. Furthermore, evidence was provided that SMG7 is required for the dephosphorylation of UPF1. Our comprehensive and comparative study of NMD feedback control in plants reveals complex and species-specific attenuation of this RNA surveillance pathway, with critical implications for the numerous functions of NMD in physiology and stress responses.
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Affiliation(s)
- Anil K Kesarwani
- Center for Plant Molecular Biology (ZMBP), University of T�bingen, Auf der Morgenstelle, 32 T�bingen, Germany
| | - Hsin-Chieh Lee
- Center for Plant Molecular Biology (ZMBP), University of T�bingen, Auf der Morgenstelle, 32 T�bingen, Germany
| | - Patrizia G Ricca
- Center for Plant Molecular Biology (ZMBP), University of T�bingen, Auf der Morgenstelle, 32 T�bingen, Germany
| | - Gabriele Sullivan
- Center for Plant Molecular Biology (ZMBP), University of T�bingen, Auf der Morgenstelle, 32 T�bingen, Germany
| | - Natalie Faiss
- Center for Plant Molecular Biology (ZMBP), University of T�bingen, Auf der Morgenstelle, 32 T�bingen, Germany
| | - Gabriele Wagner
- Center for Plant Molecular Biology (ZMBP), University of T�bingen, Auf der Morgenstelle, 32 T�bingen, Germany
| | - Anna Wunderling
- Center for Plant Molecular Biology (ZMBP), University of T�bingen, Auf der Morgenstelle, 32 T�bingen, Germany
| | - Andreas Wachter
- Center for Plant Molecular Biology (ZMBP), University of T�bingen, Auf der Morgenstelle, 32 T�bingen, Germany
- Institute for Molecular Physiology (imP), University of Mainz, Johannes von M�ller-Weg 6, Mainz, Germany
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31
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Lange H, Ndecky SYA, Gomez-Diaz C, Pflieger D, Butel N, Zumsteg J, Kuhn L, Piermaria C, Chicher J, Christie M, Karaaslan ES, Lang PLM, Weigel D, Vaucheret H, Hammann P, Gagliardi D. RST1 and RIPR connect the cytosolic RNA exosome to the Ski complex in Arabidopsis. Nat Commun 2019; 10:3871. [PMID: 31455787 PMCID: PMC6711988 DOI: 10.1038/s41467-019-11807-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/05/2019] [Indexed: 02/01/2023] Open
Abstract
The RNA exosome is a key 3’−5’ exoribonuclease with an evolutionarily conserved structure and function. Its cytosolic functions require the co-factors SKI7 and the Ski complex. Here we demonstrate by co-purification experiments that the ARM-repeat protein RESURRECTION1 (RST1) and RST1 INTERACTING PROTEIN (RIPR) connect the cytosolic Arabidopsis RNA exosome to the Ski complex. rst1 and ripr mutants accumulate RNA quality control siRNAs (rqc-siRNAs) produced by the post-transcriptional gene silencing (PTGS) machinery when mRNA degradation is compromised. The small RNA populations observed in rst1 and ripr mutants are also detected in mutants lacking the RRP45B/CER7 core exosome subunit. Thus, molecular and genetic evidence supports a physical and functional link between RST1, RIPR and the RNA exosome. Our data reveal the existence of additional cytosolic exosome co-factors besides the known Ski subunits. RST1 is not restricted to plants, as homologues with a similar domain architecture but unknown function exist in animals, including humans. Cytosolic RNA degradation by the RNA exosome requires the Ski complex. Here the authors show that the proteins RST1 and RIPR assist the RNA exosome and the Ski complex in RNA degradation, thereby preventing the production of secondary siRNAs from endogenous mRNAs.
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Affiliation(s)
- Heike Lange
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France.
| | - Simon Y A Ndecky
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Carlos Gomez-Diaz
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - David Pflieger
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Nicolas Butel
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Julie Zumsteg
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Lauriane Kuhn
- Plateforme protéomique Strasbourg Esplanade FR1589 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Christina Piermaria
- Plateforme protéomique Strasbourg Esplanade FR1589 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Johana Chicher
- Plateforme protéomique Strasbourg Esplanade FR1589 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Michael Christie
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Ezgi S Karaaslan
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | | | - Detlef Weigel
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Philippe Hammann
- Plateforme protéomique Strasbourg Esplanade FR1589 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Dominique Gagliardi
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France.
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32
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Wang Y, Shen W, Liang XH, Crooke ST. Phosphorothioate Antisense Oligonucleotides Bind P-Body Proteins and Mediate P-Body Assembly. Nucleic Acid Ther 2019; 29:343-358. [PMID: 31429620 DOI: 10.1089/nat.2019.0806] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Antisense oligonucleotides (ASOs) regulate gene expression by binding to complementary target RNA, and ASOs can be designed to take advantage of a growing array of post RNA binding molecular mechanisms. Intracellular trafficking of ASOs influences their efficacy. We have identified a number of membrane-less structures in the nucleus, nucleolus, and cytoplasm where phosphorothioate-modified ASOs (PS-ASOs) accumulate and have shown that PS-ASOs can induce the formation of new nuclear structures such as PS-bodies and paraspeckle-like structures. In this study, we report that PS-ASOs can localize to cytoplasmic processing bodies (P-bodies) and increase the number of P-bodies in cells. The antisense activity of PS-ASOs was not affected by the absence of essential P-body assembly proteins DDX6 and LSm14A. Moreover, the effects of PS-ASOs on P-body assembly were independent of their antisense activities. The phosphorothioate modification stabilizes the association between ASOs and cellular proteins and is essential for the P-body localization of ASOs. Since PS-ASOs bind to major P-body components, PS-ASOs may serve as scaffolds for P-body formation. Taken together, these results indicate that interactions of PS-ASO with proteins, rather than antisense activities, are essential for the dynamic interplay between PS-ASOs and P-bodies.
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Affiliation(s)
- Ying Wang
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California
| | - Wen Shen
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California
| | - Xue-Hai Liang
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California
| | - Stanley T Crooke
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California
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33
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Vilches Barro A, Stöckle D, Thellmann M, Ruiz-Duarte P, Bald L, Louveaux M, von Born P, Denninger P, Goh T, Fukaki H, Vermeer JEM, Maizel A. Cytoskeleton Dynamics Are Necessary for Early Events of Lateral Root Initiation in Arabidopsis. Curr Biol 2019; 29:2443-2454.e5. [PMID: 31327713 DOI: 10.1016/j.cub.2019.06.039] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/31/2019] [Accepted: 06/12/2019] [Indexed: 12/20/2022]
Abstract
How plant cells re-establish differential growth to initiate organs is poorly understood. Morphogenesis of lateral roots relies on the asymmetric cell division of initially symmetric founder cells. This division is preceded by the tightly controlled asymmetric radial expansion of these cells. The cellular mechanisms that license and ensure the coordination of these events are unknown. Here, we quantitatively analyze microtubule and F-actin dynamics during lateral root initiation. Using mutants and pharmacological and tissue-specific genetic perturbations, we show that dynamic reorganization of both microtubule and F-actin networks is necessary for the asymmetric expansion of the founder cells. This cytoskeleton remodeling intertwines with auxin signaling in the pericycle and endodermis in order for founder cells to acquire a basic polarity required for initiating lateral root development. Our results reveal the conservation of cell remodeling and polarization strategies between the Arabidopsis zygote and lateral root founder cells. We propose that coordinated, auxin-driven reorganization of the cytoskeleton licenses asymmetric cell growth and divisions during embryonic and post-embryonic organogenesis.
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Affiliation(s)
- Amaya Vilches Barro
- Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Dorothee Stöckle
- Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland
| | - Martha Thellmann
- Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland
| | - Paola Ruiz-Duarte
- Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Lotte Bald
- Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Marion Louveaux
- Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Patrick von Born
- Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Philipp Denninger
- Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Tatsuaki Goh
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma 630-0192, Japan; Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan
| | - Hidehiro Fukaki
- Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan
| | - Joop E M Vermeer
- Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland.
| | - Alexis Maizel
- Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany.
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34
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Li T, Natran A, Chen Y, Vercruysse J, Wang K, Gonzalez N, Dubois M, Inzé D. A genetics screen highlights emerging roles for CPL3, RST1 and URT1 in RNA metabolism and silencing. NATURE PLANTS 2019; 5:539-550. [PMID: 31076735 DOI: 10.1038/s41477-019-0419-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 03/28/2019] [Indexed: 05/19/2023]
Abstract
Post-transcriptional gene silencing (PTGS) is a major mechanism regulating gene expression in higher eukaryotes. To identify novel players in PTGS, a forward genetics screen was performed on an Arabidopsis thaliana line overexpressing a strong growth-repressive gene, ETHYLENE RESPONSE FACTOR6 (ERF6). We identified six independent ethyl-methanesulfonate mutants rescuing the dwarfism of ERF6-overexpressing plants as a result of transgene silencing. Among the causative genes, ETHYLENE-INSENSITIVE5, SUPERKILLER2 and HASTY1 have previously been reported to inhibit PTGS. Notably, the three other causative genes have not, to date, been related to PTGS: UTP:RNA-URIDYLYLTRANSFERASE1 (URT1), C-TERMINAL DOMAIN PHOSPHATASE-LIKE3 (CPL3) and RESURRECTION1 (RST1). We show that these genes may participate in protecting the 3' end of transgene transcripts. We present a model in which URT1, CPL3 and RST1 are classified as PTGS suppressors, as compromisation of these genes provokes the accumulation of aberrant transcripts which, in turn, trigger the production of small interfering RNAs, initiating RNA silencing.
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Affiliation(s)
- Ting Li
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Annelore Natran
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Yanjun Chen
- College of Life Science, Wuhan University, Wuhan, China
| | - Jasmien Vercruysse
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Kun Wang
- College of Life Science, Wuhan University, Wuhan, China
| | - Nathalie Gonzalez
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
- INRA, Université de Bordeaux, Villenave d'Ornon, France
| | - Marieke Dubois
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Dirk Inzé
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
- VIB Center for Plant Systems Biology, Ghent, Belgium.
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35
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Abstract
Plant growth and productivity are greatly impacted by environmental stresses. Therefore, plants have evolved mechanisms which allow them to adapt to abiotic stresses through alterations in gene expression and metabolism. In recent years, studies have investigated the role of long noncoding RNA (lncRNA) in regulating gene expression in plants and characterized their involvement in various biological functions through their regulation of DNA methylation, DNA structural modifications, histone modifications, and RNA-RNA interactions. Genome-wide transcriptome analyses have identified various types of noncoding RNAs (ncRNAs) that respond to abiotic stress. These ncRNAs are in addition to the well-known housekeeping ncRNAs, such as rRNAs, tRNAs, snoRNAs, and snRNAs. In this review, recent research pertaining to the role of lncRNAs in the response of plants to abiotic stress is summarized and discussed.
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Affiliation(s)
- Akihiro Matsui
- Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, Japan.
- Plant Epigenome Regulation Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, Japan.
| | - Motoaki Seki
- Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, Japan.
- Plant Epigenome Regulation Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, Japan.
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Kanagawa, Japan.
- Core Research for Evolutional Science and Technology, Japan Science and Technology, Kawaguchi, Saitama, Japan.
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36
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Szádeczky-Kardoss I, Gál L, Auber A, Taller J, Silhavy D. The No-go decay system degrades plant mRNAs that contain a long A-stretch in the coding region. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 275:19-27. [PMID: 30107878 DOI: 10.1016/j.plantsci.2018.07.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 05/04/2023]
Abstract
RNA quality control systems identify and degrade aberrant mRNAs, thereby preventing the accumulation of faulty proteins. Non-stop decay (NSD) and No-go decay (NGD) are closely related RNA quality control systems that act during translation. NSD degrades mRNAs lacking a stop codon, while NGD recognizes and decays mRNAs that contain translation elongation inhibitory structures. NGD has been intensively studied in yeast and animals but it has not been described in plants yet. In yeast, NGD is induced if the elongating ribosome is stalled by a strong inhibitory structure. Then, the mRNA is cleaved by an unknown nuclease and the cleavage fragments are degraded. Here we show that NGD also operates in plant. We tested several potential NGD cis-elements and found that in plants, unlike in yeast, only long A-stretches induce NGD. These long A-stretches trigger endonucleolytic cleavage, and then the 5' fragments are degraded in a Pelota-, HBS1- and SKI2- dependent manner, while XRN4 eliminates the 3' fragment. We also show that plant NGD operates gradually, the longer the A-stretch, the more efficient the cleavage. Our data suggest that mechanistically NGD is conserved in eukaryotes, although the NGD inducing cis-elements could be different. Moreover, we found that Arabidopsis AtPelota1 functions in both NGD and NSD, while AtPelota2 represses these quality control systems. The function of plant NGD will be discussed.
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Affiliation(s)
| | - Luca Gál
- Agricultural Biotechnology Institute, Szent-Györgyi 4, H-2100, Gödöllő, Hungary
| | - Andor Auber
- Agricultural Biotechnology Institute, Szent-Györgyi 4, H-2100, Gödöllő, Hungary
| | - János Taller
- University Pannonia Georgikon, Festetics 7, 8360, Keszthely, Hungary
| | - Dániel Silhavy
- Agricultural Biotechnology Institute, Szent-Györgyi 4, H-2100, Gödöllő, Hungary.
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37
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Ma Z, Castillo-González C, Wang Z, Sun D, Hu X, Shen X, Potok ME, Zhang X. Arabidopsis Serrate Coordinates Histone Methyltransferases ATXR5/6 and RNA Processing Factor RDR6 to Regulate Transposon Expression. Dev Cell 2018; 45:769-784.e6. [PMID: 29920280 DOI: 10.1016/j.devcel.2018.05.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 04/04/2018] [Accepted: 05/20/2018] [Indexed: 12/25/2022]
Abstract
Serrate (SE) is a key component in RNA metabolism. Little is known about whether and how it can regulate epigenetic silencing. Here, we report histone methyltransferases ATXR5 and ATXR6 (ATXR5/6) as novel partners of SE. ATXR5/6 deposit histone 3 lysine 27 monomethylation (H3K27me1) to promote heterochromatin formation, repress transposable elements (TEs), and control genome stability in Arabidopsis. SE binds to ATXR5/6-regulated TE loci and promotes H3K27me1 accumulation in these regions. Furthermore, SE directly enhances ATXR5 enzymatic activity in vitro. Unexpectedly, se mutation suppresses the TE reactivation and DNA re-replication phenotypes in the atxr5 atxr6 mutant. The suppression of TE expression results from triggering RNA-dependent RNA polymerase 6 (RDR6)-dependent RNA silencing in the se atxr5 atxr6 mutant. We propose that SE facilitates ATXR5/6-mediated deposition of the H3K27me1 mark while inhibiting RDR6-mediated RNA silencing to protect TE transcripts. Hence, SE coordinates epigenetic silencing and RNA processing machineries to fine-tune the TE expression.
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Affiliation(s)
- Zeyang Ma
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843, USA
| | - Claudia Castillo-González
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843, USA
| | - Zhiye Wang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843, USA
| | - Di Sun
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843, USA
| | - Xiaomei Hu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843, USA
| | - Xuefeng Shen
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843, USA; College of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Magdalena E Potok
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Xiuren Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843, USA.
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38
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Li F, Wang A. RNA decay is an antiviral defense in plants that is counteracted by viral RNA silencing suppressors. PLoS Pathog 2018; 14:e1007228. [PMID: 30075014 PMCID: PMC6101400 DOI: 10.1371/journal.ppat.1007228] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 08/20/2018] [Accepted: 07/17/2018] [Indexed: 11/19/2022] Open
Abstract
Exonuclease-mediated RNA decay in plants is known to be involved primarily in endogenous RNA degradation, and several RNA decay components have been suggested to attenuate RNA silencing possibly through competing for RNA substrates. In this paper, we report that overexpression of key cytoplasmic 5'-3' RNA decay pathway gene-encoded proteins (5'RDGs) such as decapping protein 2 (DCP2) and exoribonuclease 4 (XRN4) in Nicotiana benthamiana fails to suppress sense transgene-induced post-transcriptional gene silencing (S-PTGS). On the contrary, knock-down of these 5'RDGs attenuates S-PTGS and supresses the generation of small interfering RNAs (siRNAs). We show that 5'RDGs degrade transgene transcripts via the RNA decay pathway when the S-PTGS pathway is disabled. Thus, RNA silencing and RNA decay degrade exogenous gene transcripts in a hierarchical and coordinated manner. Moreover, we present evidence that infection by turnip mosaic virus (TuMV) activates RNA decay and 5'RDGs also negatively regulate TuMV RNA accumulation. We reveal that RNA silencing and RNA decay can mediate degradation of TuMV RNA in the same way that they target transgene transcripts. Furthermore, we demonstrate that VPg and HC-Pro, the two known viral suppressors of RNA silencing (VSRs) of potyviruses, bind to DCP2 and XRN4, respectively, and the interactions compromise their antiviral function. Taken together, our data highlight the overlapping function of the RNA silencing and RNA decay pathways in plants, as evidenced by their hierarchical and concerted actions against exogenous and viral RNA, and VSRs not only counteract RNA silencing but also subvert RNA decay to promote viral infection.
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Affiliation(s)
- Fangfang Li
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
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39
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Kørner CJ, Pitzalis N, Peña EJ, Erhardt M, Vazquez F, Heinlein M. Crosstalk between PTGS and TGS pathways in natural antiviral immunity and disease recovery. NATURE PLANTS 2018; 4:157-164. [PMID: 29497161 DOI: 10.1038/s41477-018-0117-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/31/2018] [Indexed: 05/22/2023]
Abstract
Virus-induced diseases cause severe damage to cultivated plants, resulting in crop losses. Certain plant-virus interactions allow disease recovery at later stages of infection and have the potential to reveal important molecular targets for achieving disease control. Although recovery is known to involve antiviral RNA silencing1,2, the specific components of the many plant RNA silencing pathways 3 required for recovery are not known. We found that Arabidopsis thaliana plants infected with oilseed rape mosaic virus (ORMV) undergo symptom recovery. The recovered leaves contain infectious, replicating virus, but exhibit a loss of viral suppressor of RNA silencing (VSR) protein activity. We demonstrate that recovery depends on the 21-22 nt siRNA-mediated post-transcriptional gene silencing (PTGS) pathway and on components of a transcriptional gene silencing (TGS) pathway that is known to facilitate non-cell-autonomous silencing signalling. Collectively, our observations indicate that recovery reflects the establishment of a tolerant state in infected tissues and occurs following robust delivery of antiviral secondary siRNAs from source to sink tissues, and establishment of a dosage able to block the VSR activity involved in the formation of disease symptoms.
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Affiliation(s)
- Camilla Julie Kørner
- Zurich-Basel Plant Science Center, Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Nicolas Pitzalis
- Université de Strasbourg, CNRS, IBMP UPR 2357, Strasbourg, France
| | - Eduardo José Peña
- Université de Strasbourg, CNRS, IBMP UPR 2357, Strasbourg, France
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, UNLP-CONICET, La Plata, Buenos Aires, Argentina
| | - Mathieu Erhardt
- Université de Strasbourg, CNRS, IBMP UPR 2357, Strasbourg, France
| | - Franck Vazquez
- Zurich-Basel Plant Science Center, Department of Environmental Sciences, University of Basel, Basel, Switzerland
- MDPI, Basel, Switzerland
| | - Manfred Heinlein
- Zurich-Basel Plant Science Center, Department of Environmental Sciences, University of Basel, Basel, Switzerland.
- Université de Strasbourg, CNRS, IBMP UPR 2357, Strasbourg, France.
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40
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Joh RI, Khanduja JS, Calvo IA, Mistry M, Palmieri CM, Savol AJ, Ho Sui SJ, Sadreyev RI, Aryee MJ, Motamedi M. Survival in Quiescence Requires the Euchromatic Deployment of Clr4/SUV39H by Argonaute-Associated Small RNAs. Mol Cell 2017; 64:1088-1101. [PMID: 27984744 DOI: 10.1016/j.molcel.2016.11.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/14/2016] [Accepted: 11/09/2016] [Indexed: 01/10/2023]
Abstract
Quiescence (G0) is a ubiquitous stress response through which cells enter reversible dormancy, acquiring distinct properties including reduced metabolism, resistance to stress, and long life. G0 entry involves dramatic changes to chromatin and transcription of cells, but the mechanisms coordinating these processes remain poorly understood. Using the fission yeast, here, we track G0-associated chromatin and transcriptional changes temporally and show that as cells enter G0, their survival and global gene expression programs become increasingly dependent on Clr4/SUV39H, the sole histone H3 lysine 9 (H3K9) methyltransferase, and RNAi proteins. Notably, G0 entry results in RNAi-dependent H3K9 methylation of several euchromatic pockets, prior to which Argonaute1-associated small RNAs from these regions emerge. Overall, our data reveal another function for constitutive heterochromatin proteins (the establishment of the global G0 transcriptional program) and suggest that stress-induced alterations in Argonaute-associated sRNAs can target the deployment of transcriptional regulatory proteins to specific sequences.
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Affiliation(s)
- Richard I Joh
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine, Harvard Medical School, Charlestown, MA 02129, USA
| | - Jasbeer S Khanduja
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine, Harvard Medical School, Charlestown, MA 02129, USA
| | - Isabel A Calvo
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine, Harvard Medical School, Charlestown, MA 02129, USA
| | - Meeta Mistry
- Bioinformatics Core, Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Christina M Palmieri
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine, Harvard Medical School, Charlestown, MA 02129, USA
| | - Andrej J Savol
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Shannan J Ho Sui
- Bioinformatics Core, Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Ruslan I Sadreyev
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Martin J Aryee
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine, Harvard Medical School, Charlestown, MA 02129, USA; Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Mo Motamedi
- Massachusetts General Hospital Center for Cancer Research and Department of Medicine, Harvard Medical School, Charlestown, MA 02129, USA.
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41
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Butel N, Le Masson I, Bouteiller N, Vaucheret H, Elmayan T. sgs1: a neomorphic nac52 allele impairing post-transcriptional gene silencing through SGS3 downregulation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:505-519. [PMID: 28207953 DOI: 10.1111/tpj.13508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 02/01/2017] [Indexed: 06/06/2023]
Abstract
Post-transcriptional gene silencing (PTGS) is a defense mechanism that targets invading nucleic acids from endogenous (transposons) or exogenous (pathogens, transgenes) sources. Genetic screens based on the reactivation of silenced transgenes have long been used to identify cellular components and regulators of PTGS. Here we show that the first isolated PTGS-deficient mutant, sgs1, is impaired in the transcription factor NAC52. This mutant exhibits striking similarities to a mutant impaired in the H3K4me3 demethylase JMJ14 isolated from the same genetic screen. These similarities include increased transgene promoter DNA methylation, reduced H3K4me3 and H3K36me3 levels, reduced PolII occupancy and reduced transgene mRNA accumulation. It is likely that increased DNA methylation is the cause of reduced transcription because the effect of jmj14 and sgs1 on transgene transcription is suppressed by drm2, a mutation that compromises de novo DNA methylation, suggesting that the JMJ14-NAC52 module promotes transgene transcription by preventing DNA methylation. Remarkably, sgs1 has a stronger effect than jmj14 and nac52 null alleles on PTGS systems requiring siRNA amplification, and this is due to reduced SGS3 mRNA levels in sgs1. Given that the sgs1 mutation changes a conserved amino acid of the NAC proteins involved in homodimerization, we propose that sgs1 corresponds to a neomorphic nac52 allele encoding a mutant protein that lacks wild-type NAC52 activity but promotes SGS3 downregulation. Together, these results indicate that impairment of PTGS in sgs1 is due to its dual effect on transgene transcription and SGS3 transcription, thus compromising siRNA amplification.
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Affiliation(s)
- Nicolas Butel
- Institut Jean-Pierre Bourgin, UMR 1318, INRA AgroParisTech CNRS, Université Paris-Saclay, 78000, Versailles, France
- Université Paris-Sud, Université Paris-Saclay, 91405, Orsay, France
| | - Ivan Le Masson
- Institut Jean-Pierre Bourgin, UMR 1318, INRA AgroParisTech CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Nathalie Bouteiller
- Institut Jean-Pierre Bourgin, UMR 1318, INRA AgroParisTech CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, UMR 1318, INRA AgroParisTech CNRS, Université Paris-Saclay, 78000, Versailles, France
| | - Taline Elmayan
- Institut Jean-Pierre Bourgin, UMR 1318, INRA AgroParisTech CNRS, Université Paris-Saclay, 78000, Versailles, France
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42
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Nyikó T, Auber A, Szabadkai L, Benkovics A, Auth M, Mérai Z, Kerényi Z, Dinnyés A, Nagy F, Silhavy D. Expression of the eRF1 translation termination factor is controlled by an autoregulatory circuit involving readthrough and nonsense-mediated decay in plants. Nucleic Acids Res 2017; 45:4174-4188. [PMID: 28062855 PMCID: PMC5397192 DOI: 10.1093/nar/gkw1303] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/24/2016] [Accepted: 12/28/2016] [Indexed: 12/28/2022] Open
Abstract
When a ribosome reaches a stop codon, the eukaryotic Release Factor 1 (eRF1) binds to the A site of the ribosome and terminates translation. In yeasts and plants, both over- and underexpression of eRF1 lead to altered phenotype indicating that eRF1 expression should be strictly controlled. However, regulation of eRF1 level is still poorly understood. Here we show that expression of plant eRF1 is controlled by a complex negative autoregulatory circuit, which is based on the unique features of the 3΄untranslated region (3΄UTR) of the eRF1-1 transcript. The stop codon of the eRF1-1 mRNA is in a translational readthrough promoting context, while its 3΄UTR induces nonsense-mediated decay (NMD), a translation termination coupled mRNA degradation mechanism. We demonstrate that readthrough partially protects the eRF1-1 mRNA from its 3΄UTR induced NMD, and that elevated eRF1 levels inhibit readthrough and stimulate NMD. Thus, high eRF1 level leads to reduced eRF1-1 expression, as weakened readthrough fails to protect the eRF1-1 mRNA from the more intense NMD. This eRF1 autoregulatory circuit might serve to finely balance general translation termination efficiency.
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Affiliation(s)
- Tünde Nyikó
- Department of Genetics, Agricultural Biotechnology Institute, Gödöllő, Szent-Györgyi 4, H-2100, Hungary
| | - Andor Auber
- Department of Genetics, Agricultural Biotechnology Institute, Gödöllő, Szent-Györgyi 4, H-2100, Hungary
| | - Levente Szabadkai
- Department of Genetics, Agricultural Biotechnology Institute, Gödöllő, Szent-Györgyi 4, H-2100, Hungary
| | - Anna Benkovics
- Department of Genetics, Agricultural Biotechnology Institute, Gödöllő, Szent-Györgyi 4, H-2100, Hungary
| | - Mariann Auth
- Department of Genetics, Agricultural Biotechnology Institute, Gödöllő, Szent-Györgyi 4, H-2100, Hungary
| | - Zsuzsanna Mérai
- Department of Genetics, Agricultural Biotechnology Institute, Gödöllő, Szent-Györgyi 4, H-2100, Hungary
| | - Zoltán Kerényi
- Department of Genetics, Agricultural Biotechnology Institute, Gödöllő, Szent-Györgyi 4, H-2100, Hungary
| | - Andrea Dinnyés
- Department of Genetics, Agricultural Biotechnology Institute, Gödöllő, Szent-Györgyi 4, H-2100, Hungary
| | - Ferenc Nagy
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Temesvári 62, H-6726, Hungary
| | - Dániel Silhavy
- Department of Genetics, Agricultural Biotechnology Institute, Gödöllő, Szent-Györgyi 4, H-2100, Hungary
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43
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Tsuzuki M, Motomura K, Kumakura N, Takeda A. Interconnections between mRNA degradation and RDR-dependent siRNA production in mRNA turnover in plants. JOURNAL OF PLANT RESEARCH 2017; 130:211-226. [PMID: 28197782 DOI: 10.1007/s10265-017-0906-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 12/08/2016] [Indexed: 06/06/2023]
Abstract
Accumulation of an mRNA species is determined by the balance between the synthesis and the degradation of the mRNA. Individual mRNA molecules are selectively and actively degraded through RNA degradation pathways, which include 5'-3' mRNA degradation pathway, 3'-5' mRNA degradation pathway, and RNA-dependent RNA polymerase-mediated mRNA degradation pathway. Recent studies have revealed that these RNA degradation pathways compete with each other in mRNA turnover in plants and that plants have a hidden layer of non-coding small-interfering RNA production from a set of mRNAs. In this review, we summarize the current information about plant mRNA degradation pathways in mRNA turnover and discuss the potential roles of a novel class of the endogenous siRNAs derived from plant mRNAs.
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Affiliation(s)
- Masayuki Tsuzuki
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, 153-8902, Japan
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kazuki Motomura
- Institute of Transformative Bio-Molecules, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Naoyoshi Kumakura
- Center for Sustainable Resource Science, RIKEN, Suehiro-cho 1-7-22, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Atsushi Takeda
- Department of Biotechnology, Graduate School of Life Sciences, Ritsumeikan University, Shiga, 525-8577, Japan.
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44
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Zhang X, Guo H. mRNA decay in plants: both quantity and quality matter. CURRENT OPINION IN PLANT BIOLOGY 2017; 35:138-144. [PMID: 28011423 DOI: 10.1016/j.pbi.2016.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 11/25/2016] [Accepted: 12/06/2016] [Indexed: 06/06/2023]
Abstract
In eukaryotes, degradation of messenger RNAs (mRNAs) is required for both mRNA quantity and quality control. Fine-tuning of the abundance of mRNAs that are to be translated can be achieved through a deadenylation-mediated RNA decay pathway involving progressive removal of poly(A) tails, decapping and exoribonuclease digestion. While the classical view assumes that mRNAs are degraded only after their exit from protein translation, recent studies have revealed mRNA decay can occur during translation in plants. Those mRNAs that have structural or functional defects can be filtered by translation-dependent RNA quality control pathways and rapidly degraded, so that translation fidelity is preserved. In addition, aberrant transcripts can also be efficiently eliminated through bidirectional RNA decay pathways. In the absence of those pathways, accumulation of those aberrant transcripts evokes the activation of RNA silencing, with detrimental consequences.
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Affiliation(s)
- Xinyan Zhang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
| | - Hongwei Guo
- Department of Biology, South University of Science and Technology of China, Shenzhen, Guangdong 518055, China.
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45
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Li F, Zhao N, Li Z, Xu X, Wang Y, Yang X, Liu SS, Wang A, Zhou X. A calmodulin-like protein suppresses RNA silencing and promotes geminivirus infection by degrading SGS3 via the autophagy pathway in Nicotiana benthamiana. PLoS Pathog 2017; 13:e1006213. [PMID: 28212430 PMCID: PMC5333915 DOI: 10.1371/journal.ppat.1006213] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 03/02/2017] [Accepted: 02/02/2017] [Indexed: 12/31/2022] Open
Abstract
A recently characterized calmodulin-like protein is an endogenous RNA silencing suppressor that suppresses sense-RNA induced post-transcriptional gene silencing (S-PTGS) and enhances virus infection, but the mechanism underlying calmodulin-like protein-mediated S-PTGS suppression is obscure. Here, we show that a calmodulin-like protein from Nicotiana benthamiana (NbCaM) interacts with Suppressor of Gene Silencing 3 (NbSGS3). Deletion analyses showed that domains essential for the interaction between NbSGS3 and NbCaM are also required for the subcellular localization of NbSGS3 and NbCaM suppressor activity. Overexpression of NbCaM reduced the number of NbSGS3-associated granules by degrading NbSGS3 protein accumulation in the cytoplasm. This NbCaM-mediated NbSGS3 degradation was sensitive to the autophagy inhibitors 3-methyladenine and E64d, and was compromised when key autophagy genes of the phosphatidylinositol 3-kinase (PI3K) complex were knocked down. Meanwhile, silencing of key autophagy genes within the PI3K complex inhibited geminivirus infection. Taken together these data suggest that NbCaM acts as a suppressor of RNA silencing by degrading NbSGS3 through the autophagy pathway.
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Affiliation(s)
- Fangfang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Nan Zhao
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhenghe Li
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiongbiao Xu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiuling Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shu-Sheng Liu
- Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Aiming Wang
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
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46
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Conti G, Zavallo D, Venturuzzi AL, Rodriguez MC, Crespi M, Asurmendi S. TMV induces RNA decay pathways to modulate gene silencing and disease symptoms. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 89:73-84. [PMID: 27599263 DOI: 10.1111/tpj.13323] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/23/2016] [Accepted: 08/31/2016] [Indexed: 06/06/2023]
Abstract
RNA decay pathways comprise a combination of RNA degradation mechanisms that are implicated in gene expression, development and defense responses in eukaryotes. These mechanisms are known as the RNA Quality Control or RQC pathways. In plants, another important RNA degradation mechanism is the post-transcriptional gene silencing (PTGS) mediated by small RNAs (siRNAs). Notably, the RQC pathway antagonizes PTGS by preventing the entry of dysfunctional mRNAs into the silencing pathway to avoid global degradation of mRNA by siRNAs. Viral transcripts must evade RNA degrading mechanisms, thus viruses encode PTGS suppressor proteins to counteract viral RNA silencing. Here, we demonstrate that tobacco plants infected with TMV and transgenic lines expressing TMV MP and CP (coat protein) proteins (which are not linked to the suppression of silencing) display increased transcriptional levels of RNA decay genes. These plants also showed accumulation of cytoplasmic RNA granules with altered structure, increased rates of RNA decay for transgenes and defective transgene PTGS amplification. Furthermore, knockdown of RRP41 or RRP43 RNA exosome components led to lower levels of TMV accumulation with milder symptoms after infection, several developmental defects and miRNA deregulation. Thus, we propose that TMV proteins induce RNA decay pathways (in particular exosome components) to impair antiviral PTGS and this defensive mechanism would constitute an additional counter-defense strategy that lead to disease symptoms.
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Affiliation(s)
- Gabriela Conti
- Instituto de Biotecnología, CICVyA, INTA, Hurlingham, Argentina
- CONICET, Hurlingham, Argentina
| | - Diego Zavallo
- Instituto de Biotecnología, CICVyA, INTA, Hurlingham, Argentina
| | - Andrea L Venturuzzi
- Instituto de Biotecnología, CICVyA, INTA, Hurlingham, Argentina
- CONICET, Hurlingham, Argentina
| | | | - Martin Crespi
- Institute of Plant Sciences Paris-Saclay, IPS2, CNRS, INRA, University Paris-Sud, Orsay, France
| | - Sebastian Asurmendi
- Instituto de Biotecnología, CICVyA, INTA, Hurlingham, Argentina
- CONICET, Hurlingham, Argentina
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Mäkinen K, Lõhmus A, Pollari M. Plant RNA Regulatory Network and RNA Granules in Virus Infection. FRONTIERS IN PLANT SCIENCE 2017; 8:2093. [PMID: 29312371 PMCID: PMC5732267 DOI: 10.3389/fpls.2017.02093] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 11/24/2017] [Indexed: 05/18/2023]
Abstract
Regulation of post-transcriptional gene expression on mRNA level in eukaryotic cells includes translocation, translation, translational repression, storage, mRNA decay, RNA silencing, and nonsense-mediated decay. These processes are associated with various RNA-binding proteins and cytoplasmic ribonucleoprotein complexes many of which are conserved across eukaryotes. Microscopically visible aggregations formed by ribonucleoprotein complexes are termed RNA granules. Stress granules where the translationally inactive mRNAs are stored and processing bodies where mRNA decay may occur present the most studied RNA granule types. Diverse RNP-granules are increasingly being assigned important roles in viral infections. Although the majority of the molecular level studies on the role of RNA granules in viral translation and replication have been conducted in mammalian systems, some studies link also plant virus infection to RNA granules. An increasing body of evidence indicates that plant viruses require components of stress granules and processing bodies for their replication and translation, but how extensively the cellular mRNA regulatory network is utilized by plant viruses has remained largely enigmatic. Antiviral RNA silencing, which is an important regulator of viral RNA stability and expression in plants, is commonly counteracted by viral suppressors of RNA silencing. Some of the RNA silencing suppressors localize to cellular RNA granules and have been proposed to carry out their suppression functions there. Moreover, plant nucleotide-binding leucine-rich repeat protein-mediated virus resistance has been linked to enhanced processing body formation and translational repression of viral RNA. Many interesting questions relate to how the pathways of antiviral RNA silencing leading to viral RNA degradation and/or repression of translation, suppression of RNA silencing and viral RNA translation converge in plants and how different RNA granules and their individual components contribute to these processes. In this review we discuss the roles of cellular RNA regulatory mechanisms and RNA granules in plant virus infection in the light of current knowledge and compare the findings to those made in animal virus studies.
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Liu L, Chen X. RNA Quality Control as a Key to Suppressing RNA Silencing of Endogenous Genes in Plants. MOLECULAR PLANT 2016; 9:826-36. [PMID: 27045817 PMCID: PMC5123867 DOI: 10.1016/j.molp.2016.03.011] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 03/10/2016] [Accepted: 03/14/2016] [Indexed: 05/19/2023]
Abstract
RNA quality control of endogenous RNAs is an integral part of eukaryotic gene expression and often relies on exonucleolytic degradation to eliminate dysfunctional transcripts. In parallel, exogenous and selected endogenous RNAs are degraded through RNA silencing, which is a genome defense mechanism used by many eukaryotes. In plants, RNA silencing is triggered by the production of double-stranded RNAs (dsRNAs) by RNA-DEPENDENT RNA POLYMERASEs (RDRs) and proceeds through small interfering (si) RNA-directed, ARGONAUTE (AGO)-mediated cleavage of homologous transcripts. Many studies revealed that plants avert inappropriate posttranscriptional gene silencing of endogenous coding genes by using RNA surveillance mechanisms as a safeguard to protect their transcriptome profiles. The tug of war between RNA surveillance and RNA silencing ensures the appropriate partitioning of endogenous RNA substrates among these degradation pathways. Here we review recent advances on RNA quality control and its role in the suppression of RNA silencing at endogenous genes and discuss the mechanisms underlying the crosstalk among these pathways.
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Affiliation(s)
- Lin Liu
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, P.R. China; Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Xuemei Chen
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, P.R. China; Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA 92521, USA; Howard Hughes Medical Institute, University of California, Riverside, CA 92521, USA.
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Meteignier LV, Zhou J, Cohen M, Bhattacharjee S, Brosseau C, Chan MGC, Robatzek S, Moffett P. NB-LRR signaling induces translational repression of viral transcripts and the formation of RNA processing bodies through mechanisms differing from those activated by UV stress and RNAi. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:2353-66. [PMID: 26889008 DOI: 10.1093/jxb/erw042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plant NB-LRR proteins confer resistance to multiple pathogens, including viruses. Although the recognition of viruses by NB-LRR proteins is highly specific, previous studies have suggested that NB-LRR activation results in a response that targets all viruses in the infected cell. Using an inducible system to activate NB-LRR defenses, we find that NB-LRR signaling does not result in the degradation of viral transcripts, but rather prevents them from associating with ribosomes and translating their genetic material. This indicates that defense against viruses involves the repression of viral RNA translation. This repression is specific to viral transcripts and does not involve a global shutdown of host cell translation. As a consequence of the repression of viral RNA translation, NB-LRR responses induce a dramatic increase in the biogenesis of RNA processing bodies (PBs). We demonstrate that other pathways that induce translational repression, such as UV irradiation and RNAi, also induce PBs. However, by investigating the phosphorylation status of eIF2α and by using suppressors of RNAi we show that the mechanisms leading to PB induction by NB-LRR signaling are different from these stimuli, thus defining a distinct type of translational control and anti-viral mechanism in plants.
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Affiliation(s)
- Louis-Valentin Meteignier
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, QC, Canada
| | - Ji Zhou
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK The Genome Analysis Centre & John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Mathias Cohen
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, QC, Canada
| | - Saikat Bhattacharjee
- Regional Centre for Biotechnology, 180, Udyog Vihar Phase I, Gurgaon-122016, India
| | - Chantal Brosseau
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, QC, Canada
| | - Maria Goretty Caamal Chan
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, QC, Canada
| | - Silke Robatzek
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK
| | - Peter Moffett
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, QC, Canada
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Elvira-Matelot E, Bardou F, Ariel F, Jauvion V, Bouteiller N, Le Masson I, Cao J, Crespi MD, Vaucheret H. The Nuclear Ribonucleoprotein SmD1 Interplays with Splicing, RNA Quality Control, and Posttranscriptional Gene Silencing in Arabidopsis. THE PLANT CELL 2016; 28:426-38. [PMID: 26842463 PMCID: PMC4790881 DOI: 10.1105/tpc.15.01045] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 01/29/2016] [Accepted: 01/29/2016] [Indexed: 05/18/2023]
Abstract
RNA quality control (RQC) eliminates aberrant RNAs based on their atypical structure, whereas posttranscriptional gene silencing (PTGS) eliminates both aberrant and functional RNAs through the sequence-specific action of short interfering RNAs (siRNAs). The Arabidopsis thaliana mutant smd1b was identified in a genetic screen for PTGS deficiency, revealing the involvement of SmD1, a component of the Smith (Sm) complex, in PTGS. The smd1a and smd1b single mutants are viable, but the smd1a smd1b double mutant is embryo-lethal, indicating that SmD1 function is essential. SmD1b resides in nucleoli and nucleoplasmic speckles, colocalizing with the splicing-related factor SR34. Consistent with this, the smd1b mutant exhibits intron retention at certain endogenous mRNAs. SmD1 binds to RNAs transcribed from silenced transgenes but not nonsilenced ones, indicating a direct role in PTGS. Yet, mutations in the RQC factors UPFRAMESHIFT3, EXORIBONUCLEASE2 (XRN2), XRN3, and XRN4 restore PTGS in smd1b, indicating that SmD1 is not essential for but rather facilitates PTGS. Moreover, the smd1b mtr4 double mutant is embryo-lethal, suggesting that SmD1 is essential for mRNA TRANSPORT REGULATOR4-dependent RQC. These results indicate that SmD1 interplays with splicing, RQC, and PTGS. We propose that SmD1 facilitates PTGS by protecting transgene-derived aberrant RNAs from degradation by RQC in the nucleus, allowing sufficient amounts to enter cytoplasmic siRNA bodies to activate PTGS.
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Affiliation(s)
- Emilie Elvira-Matelot
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78026 Versailles Cedex, France
| | - Florian Bardou
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA, Universités Paris-Sud, Evry, Paris-Diderot, Sorbonne Paris-Cité, Université Paris-Saclay, 91405 Orsay, France
| | - Federico Ariel
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA, Universités Paris-Sud, Evry, Paris-Diderot, Sorbonne Paris-Cité, Université Paris-Saclay, 91405 Orsay, France
| | - Vincent Jauvion
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78026 Versailles Cedex, France
| | - Nathalie Bouteiller
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78026 Versailles Cedex, France
| | - Ivan Le Masson
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78026 Versailles Cedex, France
| | - Jun Cao
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Martin D Crespi
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA, Universités Paris-Sud, Evry, Paris-Diderot, Sorbonne Paris-Cité, Université Paris-Saclay, 91405 Orsay, France
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78026 Versailles Cedex, France
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