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Baraniecka P, Seibt W, Groten K, Kessler D, McGale E, Gase K, Baldwin IT, Pannell JR. Prezygotic mate selection is only partially correlated with the expression of NaS-like RNases and affects offspring phenotypes. THE NEW PHYTOLOGIST 2024; 242:2832-2844. [PMID: 38581189 DOI: 10.1111/nph.19741] [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: 12/18/2023] [Accepted: 03/21/2024] [Indexed: 04/08/2024]
Abstract
Nicotiana attenuata styles preferentially select pollen from among accessions with corresponding expression patterns of NaS-like-RNases (SLRs), and the postpollination ethylene burst (PPEB) is an accurate predictor of seed siring success. However, the ecological consequences of mate selection, its effect on the progeny, and the role of SLRs in the control of ethylene signaling remain unknown. We explored the link between the magnitude of the ethylene burst and expression of the SLRs in a set of recombinant inbred lines (RILs), dissected the genetic underpinnings of mate selection through genome-wide association study (GWAS), and examined its outcome for phenotypes in the next generation. We found that high levels of PPEB are associated with the absence of SLR2 in most of the tested RILs. We identified candidate genes potentially involved in the control of mate selection and showed that pollination of maternal genotypes with their favored pollen donors produces offspring with longer roots. When the maternal genotypes are only able to select against nonfavored pollen donors, the selection for such positive traits is abolished. We conclude that plants' ability of mate choice contributes to measurable changes in progeny phenotypes and is thus likely a target of selection.
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Affiliation(s)
| | - Wibke Seibt
- MPI for Chemical Ecology, Hans-Knöll-Str. 8, Jena, 07745, Germany
| | - Karin Groten
- MPI for Chemical Ecology, Hans-Knöll-Str. 8, Jena, 07745, Germany
| | - Danny Kessler
- MPI for Chemical Ecology, Hans-Knöll-Str. 8, Jena, 07745, Germany
| | - Erica McGale
- Department of Ecology and Evolution, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Klaus Gase
- MPI for Chemical Ecology, Hans-Knöll-Str. 8, Jena, 07745, Germany
| | - Ian T Baldwin
- MPI for Chemical Ecology, Hans-Knöll-Str. 8, Jena, 07745, Germany
| | - John R Pannell
- Department of Ecology and Evolution, University of Lausanne, Lausanne, CH-1015, Switzerland
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2
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The biological functions of nonsense-mediated mRNA decay in plants: RNA quality control and beyond. Biochem Soc Trans 2023; 51:31-39. [PMID: 36695509 DOI: 10.1042/bst20211231] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 01/26/2023]
Abstract
Nonsense-mediated mRNA decay (NMD) is an evolutionarily conserved quality control pathway that inhibits the expression of transcripts containing premature termination codon. Transcriptome and phenotypic studies across a range of organisms indicate roles of NMD beyond RNA quality control and imply its involvement in regulating gene expression in a wide range of physiological processes. Studies in moss Physcomitrella patens and Arabidopsis thaliana have shown that NMD is also important in plants where it contributes to the regulation of pathogen defence, hormonal signalling, circadian clock, reproduction and gene evolution. Here, we provide up to date overview of the biological functions of NMD in plants. In addition, we discuss several biological processes where NMD factors implement their function through NMD-independent mechanisms.
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Zhang C, Gong R, Zhong H, Dai C, Zhang R, Dong J, Li Y, Liu S, Hu J. Integrated multi-locus genome-wide association studies and transcriptome analysis for seed yield and yield-related traits in Brassica napus. FRONTIERS IN PLANT SCIENCE 2023; 14:1153000. [PMID: 37123841 PMCID: PMC10140536 DOI: 10.3389/fpls.2023.1153000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 03/21/2023] [Indexed: 05/03/2023]
Abstract
Rapeseed (Brassica napus L.), the third largest oil crop, is an important source of vegetable oil and biofuel for the world. Although the breeding and yield has been improved, rapeseed still has the lowest yield compared with other major crops. Thus, increasing rapeseed yield is essential for the high demand of vegetable oil and high-quality protein for live stocks. Silique number per plant (SN), seed per pod (SP), and 1000-seed weight (SW) are the three important factors for seed yield in rapeseed. Some yield-related traits, including plant height (PH), flowering time (FT), primary branch number (BN) and silique number per inflorescence (SI) also affect the yield per plant (YP). Using six multi-locus genome-wide association study (ML-GWAS) approaches, a total of 908 yield-related quantitative trait nucleotides (QTNs) were identified in a panel consisting of 403 rapeseed core accessions based on whole-genome sequencing. Integration of ML-GWAS with transcriptome analysis, 79 candidate genes, including BnaA09g39790D (RNA helicase), BnaA09g39950D (Lipase) and BnaC09g25980D (SWEET7), were further identified and twelve genes were validated by qRT-PCRs to affect the SW or SP in rapeseed. The distribution of superior alleles from nineteen stable QTNs in 20 elite rapeseed accessions suggested that the high-yielding accessions contained more superior alleles. These results would contribute to a further understanding of the genetic basis of yield-related traits and could be used for crop improvement in B. napus.
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Affiliation(s)
- Cuiping Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, China
| | - Ruolin Gong
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, China
| | - Hua Zhong
- Cancer Epidemiology Division, Population Sciences in the Pacific Program, University of Hawaii at Manoa, Honolulu, HI, United States
| | - Chunyan Dai
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, China
| | - Ru Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, China
| | - Jungang Dong
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, China
| | - Yangsheng Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Shuai Liu
- Cancer Epidemiology Division, Population Sciences in the Pacific Program, University of Hawaii at Manoa, Honolulu, HI, United States
- *Correspondence: Jihong Hu, ; Shuai Liu,
| | - Jihong Hu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, China
- *Correspondence: Jihong Hu, ; Shuai Liu,
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4
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Andjus S, Morillon A, Wery M. From Yeast to Mammals, the Nonsense-Mediated mRNA Decay as a Master Regulator of Long Non-Coding RNAs Functional Trajectory. Noncoding RNA 2021; 7:ncrna7030044. [PMID: 34449682 PMCID: PMC8395947 DOI: 10.3390/ncrna7030044] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 12/22/2022] Open
Abstract
The Nonsense-Mediated mRNA Decay (NMD) has been classically viewed as a translation-dependent RNA surveillance pathway degrading aberrant mRNAs containing premature stop codons. However, it is now clear that mRNA quality control represents only one face of the multiple functions of NMD. Indeed, NMD also regulates the physiological expression of normal mRNAs, and more surprisingly, of long non-coding (lnc)RNAs. Here, we review the different mechanisms of NMD activation in yeast and mammals, and we discuss the molecular bases of the NMD sensitivity of lncRNAs, considering the functional roles of NMD and of translation in the metabolism of these transcripts. In this regard, we describe several examples of functional micropeptides produced from lncRNAs. We propose that translation and NMD provide potent means to regulate the expression of lncRNAs, which might be critical for the cell to respond to environmental changes.
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Affiliation(s)
- Sara Andjus
- ncRNA, Epigenetic and Genome Fluidity, Institut Curie, PSL University, Sorbonne Université, CNRS UMR3244, 26 Rue d’Ulm, CEDEX 05, F-75248 Paris, France;
| | - Antonin Morillon
- ncRNA, Epigenetic and Genome Fluidity, Institut Curie, Sorbonne Université, CNRS UMR3244, 26 Rue d’Ulm, CEDEX 05, F-75248 Paris, France
- Correspondence: (A.M.); (M.W.)
| | - Maxime Wery
- ncRNA, Epigenetic and Genome Fluidity, Institut Curie, Sorbonne Université, CNRS UMR3244, 26 Rue d’Ulm, CEDEX 05, F-75248 Paris, France
- Correspondence: (A.M.); (M.W.)
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Dutta M, Moin M, Saha A, Dutta D, Bakshi A, Kirti PB. Gain-of-function mutagenesis through activation tagging identifies XPB2 and SEN1 helicase genes as potential targets for drought stress tolerance in rice. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2021; 134:2253-2272. [PMID: 33821294 DOI: 10.1007/s00122-021-03823-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 03/23/2021] [Indexed: 05/13/2023]
Abstract
XPB2 and SEN1 helicases were identified through activation tagging as potential candidate genes in rice for inducing high water-use efficiency (WUE) and maintaining sustainable yield under drought stress. As a follow-up on the high-water-use-efficiency screening and physiological analyses of the activation-tagged gain-of-function mutant lines that were developed in an indica rice variety, BPT-5204 (Moin et al. in Plant Cell Environ 39:2440-2459, 2016a, https://doi.org/10.1111/pce.12796 ), we have identified two gain-of-function mutant lines (XM3 and SM4), which evidenced the activation of two helicases, ATP-dependent DNA helicase (XPB2) and RNA helicase (SEN1), respectively. We performed the transcript profiling of XPB2 and SEN1 upon exposure to various stress conditions and found their significant upregulation, particularly in ABA and PEG treatments. Extensive morpho-physiological and biochemical analyses based on 24 metrics were performed under dehydration stress (PEG) and phytohormone (ABA) treatments for the wild-type and the two mutant lines. Principal component analysis (PCA) performed on the dataset captured 72.73% of the cumulative variance using the parameters influencing the first two principal components. The tagged mutants exhibited reduced leaf wilting, improved revival efficiency, constant amylose:amylopectin ratio, high chlorophyll and proline contents, profuse tillering, high quantum efficiency and yield-related traits with respect to their controls. These observations were further validated under greenhouse conditions by the periodic withdrawal of water at the pot level. Germination of the seeds of these mutant lines indicated their insensitivity to high ABA concentration. The associated upregulation of stress-specific genes further suggests that their drought tolerance might be because of the coordinated expression of several stress-responsive genes in these two mutants. Altogether, our results provided a firm basis for SEN1 and XPB2 as potential candidates for manipulation of drought tolerance and improving rice performance and yield under limited water conditions.
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Affiliation(s)
- Mouboni Dutta
- Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Mazahar Moin
- Biotechnology Division, Indian Institute of Rice Research, Hyderabad, 500030, India.
| | - Anusree Saha
- Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Dibyendu Dutta
- Department of Chemical Engineering, Indian Institute of Technology, Bombay, Mumbai, 400076, India
| | - Achala Bakshi
- Biotechnology Division, Indian Institute of Rice Research, Hyderabad, 500030, India
| | - P B Kirti
- Agri Biotech Foundation, PJTS Agricultural University Campus, Hyderabad, 500030, India.
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6
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Li C, Gong X, Zhang B, Liang Z, Wong CE, See BYH, Yu H. TOP1α, UPF1, and TTG2 regulate seed size in a parental dosage-dependent manner. PLoS Biol 2020; 18:e3000930. [PMID: 33156841 PMCID: PMC7673560 DOI: 10.1371/journal.pbio.3000930] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 11/18/2020] [Accepted: 09/24/2020] [Indexed: 11/19/2022] Open
Abstract
Cues of maternal and paternal origins interact to control seed development, and the underlying molecular mechanisms are still far from clear. Here, we show that TOPOISOMERASE Iα (TOP1α), UP-FRAMESHIFT SUPPRESSOR 1 (UPF1), and TRANSPARENT TESTA GLABRA2 (TTG2) gametophytically, biparentally regulate seed size in Arabidopsis. TOP1α and UPF1 are mainly expressed in antipodal cells, and loss of their function leads to ectopic TTG2 expression in these female gametophytic cells. We further demonstrate that TOP1α and UPF1 directly repress TTG2 expression through affecting its chromatin status and determine its relative expression in antipodal cells versus sperm cells, which controls seed size in a dosage-dependent and parent-of-origin-dependent manner. The molecular interplay among these three genes explains their biparental gametophytic effect during diploidy and interploidy reciprocal crosses. Taken together, our findings reveal a molecular framework of parental interaction for seed size control. Cues of maternal and paternal origin interact to control seed development, and the underlying molecular mechanisms are still far from clear. This study shows that in Arabidopsis, the relative dosage of the transcription factor TTG2 between antipodal cells and sperm cells at the beginning of seed development determines seed size under the control of TOP1α and UPF1.
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Affiliation(s)
- Chengxiang Li
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore
| | - Ximing Gong
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Bin Zhang
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore
| | - Zhe Liang
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Chui Eng Wong
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore
| | - Benjamin Yen How See
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Hao Yu
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore
- * E-mail:
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7
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Ohtani M, Wachter A. NMD-Based Gene Regulation-A Strategy for Fitness Enhancement in Plants? PLANT & CELL PHYSIOLOGY 2019; 60:1953-1960. [PMID: 31111919 DOI: 10.1093/pcp/pcz090] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 04/22/2019] [Indexed: 05/20/2023]
Abstract
Post-transcriptional RNA quality control is a vital issue for all eukaryotes to secure accurate gene expression, both on a qualitative and quantitative level. Among the different mechanisms, nonsense-mediated mRNA decay (NMD) is an essential surveillance system that triggers degradation of both aberrant and physiological transcripts. By targeting a substantial fraction of all transcripts for degradation, including many alternative splicing variants, NMD has a major impact on shaping transcriptomes. Recent progress on the transcriptome-wide profiling and physiological analyses of NMD-deficient plant mutants revealed crucial roles for NMD in gene regulation and environmental responses. In this review, we will briefly summarize our current knowledge of the recognition and degradation of NMD targets, followed by an account of NMD's regulation and physiological functions. We will specifically discuss plant-specific aspects of RNA quality control and its functional contribution to the fitness and environmental responses of plants.
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Affiliation(s)
- Misato Ohtani
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Andreas Wachter
- Institute for Molecular Physiology (imP), University of Mainz, Johannes von M�ller-Weg 6, Mainz, Germany
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8
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Chiam NC, Fujimura T, Sano R, Akiyoshi N, Hiroyama R, Watanabe Y, Motose H, Demura T, Ohtani M. Nonsense-Mediated mRNA Decay Deficiency Affects the Auxin Response and Shoot Regeneration in Arabidopsis. PLANT & CELL PHYSIOLOGY 2019; 60:2000-2014. [PMID: 31386149 DOI: 10.1093/pcp/pcz154] [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: 11/29/2018] [Accepted: 07/21/2019] [Indexed: 06/10/2023]
Abstract
Plants generally possess a strong ability to regenerate organs; for example, in tissue culture, shoots can regenerate from callus, a clump of actively proliferating, undifferentiated cells. Processing of pre-mRNA and ribosomal RNAs is important for callus formation and shoot regeneration. However, our knowledge of the roles of RNA quality control via the nonsense-mediated mRNA decay (NMD) pathway in shoot regeneration is limited. Here, we examined the shoot regeneration phenotypes of the low-beta-amylase1 (lba1)/upstream frame shift1-1 (upf1-1) and upf3-1 mutants, in which the core NMD components UPF1 and UPF3 are defective. These mutants formed callus from hypocotyl explants normally, but this callus behaved abnormally during shoot regeneration: the mutant callus generated numerous adventitious root structures instead of adventitious shoots in an auxin-dependent manner. Quantitative RT-PCR and microarray analyses showed that the upf mutations had widespread effects during culture on shoot-induction medium. In particular, the expression patterns of early auxin response genes, including those encoding AUXIN/INDOLE ACETIC ACID (AUX/IAA) family members, were significantly affected in the upf mutants. Also, the upregulation of shoot apical meristem-related transcription factor genes, such as CUP-SHAPED COTYLEDON1 (CUC1) and CUC2, was inhibited in the mutants. Taken together, these results indicate that NMD-mediated transcriptomic regulation modulates the auxin response in plants and thus plays crucial roles in the early stages of shoot regeneration.
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Affiliation(s)
- Nyet-Cheng Chiam
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Tomoyo Fujimura
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Ryosuke Sano
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Nobuhiro Akiyoshi
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Ryoko Hiroyama
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Yuichiro Watanabe
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Hiroyasu Motose
- Department of Biological Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Taku Demura
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Misato Ohtani
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
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9
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Gong P, Luo Y, Huang F, Chen Y, Zhao C, Wu X, Li K, Yang X, Cheng F, Xiang X, Wu C, Pan G. Disruption of a Upf1-like helicase-encoding gene OsPLS2 triggers light-dependent premature leaf senescence in rice. PLANT MOLECULAR BIOLOGY 2019; 100:133-149. [PMID: 30843130 DOI: 10.1007/s11103-019-00848-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 02/21/2019] [Indexed: 05/21/2023]
Abstract
The OsPLS2 locus was isolated and cloned by map-based cloning that encodes a Upf1-like helicase. Disruption of OsPLS2 accelerated light-dependent leaf senescence in the rice mutant of ospls2. Leaf senescence is a very complex physiological process controlled by both genetic and environmental factors, however its underlying molecular mechanisms remain elusive. In this study, we report a novel Oryza sativa premature leaf senescence mutant (ospls2). Through map-based cloning, a G-to-A substitution was determined at the 1st nucleotide of the 13th intron in the OsPLS2 gene that encodes a Upf1-like helicase. This mutation prompts aberrant splicing of OsPLS2 messenger and consequent disruption of its full-length protein translation, suggesting a negative role of OsPLS2 in regulating leaf senescence. Wild-type rice accordingly displayed a progressive drop of OsPSL2 protein levels with age-dependent leaf senescence. Shading and light filtration studies showed that the ospls2 phenotype, which was characteristic of photo-oxidative stress and reactive oxygen species (ROS) accumulation, was an effect of irritation by light. When continuously exposed to far-red light, exogenous H2O2 and/or abscisic acid (ABA), the ospls2 mutant sustained hypersensitive leaf senescence. In consistence, light and ROS signal pathways in ospls2 were activated by down-regulation of phytochrome genes, and up-regulation of PHYTOCHROME-INTERACTING FACTORS (PIFs) and WRKY genes, all promoting leaf senescence. Together, these data indicated that OsPLS2 played an essential role in leaf senescence and its disruption triggered light-dependent leaf senescence in rice.
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Affiliation(s)
- Pan Gong
- Department of Agronomy, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Yanmin Luo
- Department of Agronomy, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Fudeng Huang
- Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, People's Republic of China
| | - Yaodong Chen
- Department of Agronomy, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Chaoyue Zhao
- Department of Agronomy, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Xin Wu
- Department of Agronomy, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Kunyu Li
- Department of Agronomy, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Xi Yang
- Department of Agronomy, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Fangmin Cheng
- Department of Agronomy, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Xun Xiang
- Experimental Teaching Center, College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Chunyan Wu
- Environmental Resources and Soil Fertilizer Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, People's Republic of China
| | - Gang Pan
- Department of Agronomy, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China.
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Multiple Nonsense-Mediated mRNA Processes Require Smg5 in Drosophila. Genetics 2018; 209:1073-1084. [PMID: 29903866 DOI: 10.1534/genetics.118.301140] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 06/09/2018] [Indexed: 01/09/2023] Open
Abstract
The nonsense-mediated messenger RNA (mRNA) decay (NMD) pathway is a cellular quality control and post-transcriptional gene regulatory mechanism and is essential for viability in most multicellular organisms . A complex of proteins has been identified to be required for NMD function to occur; however, there is an incomplete understanding of the individual contributions of each of these factors to the NMD process. Central to the NMD process are three proteins, Upf1 (SMG-2), Upf2 (SMG-3), and Upf3 (SMG-4), which are found in all eukaryotes, with Upf1 and Upf2 being absolutely required for NMD in all organisms in which their functions have been examined. The other known NMD factors, Smg1, Smg5, Smg6, and Smg7, are more variable in their presence in different orders of organisms and are thought to have a more regulatory role. Here we present the first genetic analysis of the NMD factor Smg5 in Drosophila Surprisingly, we find that unlike the other analyzed Smg genes in this organism, Smg5 is essential for NMD activity. We found this is due in part to a requirement for Smg5 in both the activity of Smg6-dependent endonucleolytic cleavage, as well as an additional Smg6-independent mechanism. Redundancy between these degradation pathways explains why some Drosophila NMD genes are not required for all NMD-pathway activity. We also found that while the NMD component Smg1 has only a minimal role in Drosophila NMD during normal conditions, it becomes essential when NMD activity is compromised by partial loss of Smg5 function. Our findings suggest that not all NMD complex components are required for NMD function at all times, but instead are utilized in a context-dependent manner in vivo.
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11
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Capitao C, Shukla N, Wandrolova A, Mittelsten Scheid O, Riha K. Functional Characterization of SMG7 Paralogs in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2018; 9:1602. [PMID: 30459790 PMCID: PMC6232500 DOI: 10.3389/fpls.2018.01602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 10/17/2018] [Indexed: 05/07/2023]
Abstract
SMG7 proteins are evolutionary conserved across eukaryotes and primarily known for their function in nonsense mediated RNA decay (NMD). In contrast to other NMD factors, SMG7 proteins underwent independent expansions during evolution indicating their propensity to adopt novel functions. Here we characterized SMG7 and SMG7-like (SMG7L) paralogs in Arabidopsis thaliana. SMG7 retained its role in NMD and additionally appears to have acquired another function in meiosis. We inactivated SMG7 by CRISPR/Cas9 mutagenesis and showed that, in contrast to our previous report, SMG7 is not an essential gene in Arabidopsis. Furthermore, our data indicate that the N-terminal phosphoserine-binding domain is required for both NMD and meiosis. Phenotypic analysis of SMG7 and SMG7L double mutants did not indicate any functional redundancy between the two genes, suggesting neofunctionalization of SMG7L. Finally, protein sequence comparison together with a phenotyping of T-DNA insertion mutants identified several conserved regions specific for SMG7 that may underlie its role in NMD and meiosis. This information provides a framework for deciphering the non-canonical functions of SMG7-family proteins.
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Affiliation(s)
- Claudio Capitao
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna Biocenter, Vienna, Austria
| | - Neha Shukla
- Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Aneta Wandrolova
- Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Ortrun Mittelsten Scheid
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna Biocenter, Vienna, Austria
| | - Karel Riha
- Central European Institute of Technology, Masaryk University, Brno, Czechia
- *Correspondence: Karel Riha,
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Dani KGS, Kodandaramaiah U. Plant and Animal Reproductive Strategies: Lessons from Offspring Size and Number Tradeoffs. Front Ecol Evol 2017. [DOI: 10.3389/fevo.2017.00038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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13
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Tao Y, Mace ES, Tai S, Cruickshank A, Campbell BC, Zhao X, Van Oosterom EJ, Godwin ID, Botella JR, Jordan DR. Whole-Genome Analysis of Candidate genes Associated with Seed Size and Weight in Sorghum bicolor Reveals Signatures of Artificial Selection and Insights into Parallel Domestication in Cereal Crops. FRONTIERS IN PLANT SCIENCE 2017. [PMID: 28769949 DOI: 10.3389/fp/s.2017.01237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Seed size and seed weight are major quality attributes and important determinants of yield that have been strongly selected for during crop domestication. Limited information is available about the genetic control and genes associated with seed size and weight in sorghum. This study identified sorghum orthologs of genes with proven effects on seed size and weight in other plant species and searched for evidence of selection during domestication by utilizing resequencing data from a diversity panel. In total, 114 seed size candidate genes were identified in sorghum, 63 of which exhibited signals of purifying selection during domestication. A significant number of these genes also had domestication signatures in maize and rice, consistent with the parallel domestication of seed size in cereals. Seed size candidate genes that exhibited differentially high expression levels in seed were also found more likely to be under selection during domestication, supporting the hypothesis that modification to seed size during domestication preferentially targeted genes for intrinsic seed size rather than genes associated with physiological factors involved in the carbohydrate supply and transport. Our results provide improved understanding of the complex genetic control of seed size and weight and the impact of domestication on these genes.
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Affiliation(s)
- Yongfu Tao
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
| | - Emma S Mace
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
- Department of Agriculture and Fisheries, Hermitage Research FacilityWarwick, QLD, Australia
| | | | - Alan Cruickshank
- Department of Agriculture and Fisheries, Hermitage Research FacilityWarwick, QLD, Australia
| | - Bradley C Campbell
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - Xianrong Zhao
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
| | - Erik J Van Oosterom
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandBrisbane, QLD, Australia
| | - Ian D Godwin
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - Jose R Botella
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - David R Jordan
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
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14
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Nasim Z, Fahim M, Ahn JH. Possible Role of MADS AFFECTING FLOWERING 3 and B-BOX DOMAIN PROTEIN 19 in Flowering Time Regulation of Arabidopsis Mutants with Defects in Nonsense-Mediated mRNA Decay. FRONTIERS IN PLANT SCIENCE 2017; 8:191. [PMID: 28261246 PMCID: PMC5306368 DOI: 10.3389/fpls.2017.00191] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 01/30/2017] [Indexed: 05/02/2023]
Abstract
Eukaryotic cells use nonsense-mediated mRNA decay (NMD) to clear aberrant mRNAs from the cell, thus preventing the accumulation of truncated proteins. In Arabidopsis, two UP-Frameshift (UPF) proteins, UPF1 and UPF3, play a critical role in NMD. Although deficiency of UPF1 and UPF3 leads to various developmental defects, little is known about the mechanism underlying the regulation of flowering time by NMD. Here, we showed that the upf1-5 and upf3-1 mutants had a late-flowering phenotype under long-day conditions and the upf1-5 upf3-1 double mutants had an additive effect in delaying flowering time. RNA sequencing of the upf mutants revealed that UPF3 exerted a stronger effect than UPF1 in the UPF-mediated regulation of flowering time. Among genes known to regulate flowering time, FLOWERING LOCUS C (FLC) mRNA levels increased (up to 8-fold) in upf mutants, as confirmed by qPCR. The upf1-5, upf3-1, and upf1-5 upf3-1 mutants responded to vernalization, suggesting a role of FLC in delayed flowering of upf mutants. Consistent with the high FLC transcript levels and delayed flowering in upf mutants, levels of FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) mRNAs were reduced in the upf mutants. However, RNA-seq did not identify an aberrant FLC transcript containing a premature termination codon (PTC), suggesting that FLC is not a direct target in the regulation of flowering time by NMD. Among flowering time regulators that act in an FLC-dependent manner, we found that MAF3, NF-YA2, NF-YA5, and TAF14 showed increased transcript levels in upf mutants. We also found that BBX19 and ATC, which act in an FLC-independent manner, showed increased transcript levels in upf mutants. An aberrant transcript containing a PTC was identified from MAF3 and BBX19 and the levels of the aberrant transcripts increased in upf mutants. Taking these results together, we propose that the late-flowering phenotype of upf mutants is mediated by at least two different pathways, namely, by MAF3 in an FLC-dependent manner and by BBX19 in an FLC-independent manner.
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Affiliation(s)
- Zeeshan Nasim
- Creative Research Initiatives, Department of Life Sciences, Korea UniversitySeoul, South Korea
| | - Muhammad Fahim
- Genetic Resources Conservation Lab, Institute of Biotechnology and Genetic Engineering, University of AgriculturePeshawar, Pakistan
| | - Ji Hoon Ahn
- Creative Research Initiatives, Department of Life Sciences, Korea UniversitySeoul, South Korea
- *Correspondence: Ji Hoon Ahn
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15
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Tao Y, Mace ES, Tai S, Cruickshank A, Campbell BC, Zhao X, Van Oosterom EJ, Godwin ID, Botella JR, Jordan DR. Whole-Genome Analysis of Candidate genes Associated with Seed Size and Weight in Sorghum bicolor Reveals Signatures of Artificial Selection and Insights into Parallel Domestication in Cereal Crops. FRONTIERS IN PLANT SCIENCE 2017; 8:1237. [PMID: 28769949 PMCID: PMC5513986 DOI: 10.3389/fpls.2017.01237] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 06/30/2017] [Indexed: 05/22/2023]
Abstract
Seed size and seed weight are major quality attributes and important determinants of yield that have been strongly selected for during crop domestication. Limited information is available about the genetic control and genes associated with seed size and weight in sorghum. This study identified sorghum orthologs of genes with proven effects on seed size and weight in other plant species and searched for evidence of selection during domestication by utilizing resequencing data from a diversity panel. In total, 114 seed size candidate genes were identified in sorghum, 63 of which exhibited signals of purifying selection during domestication. A significant number of these genes also had domestication signatures in maize and rice, consistent with the parallel domestication of seed size in cereals. Seed size candidate genes that exhibited differentially high expression levels in seed were also found more likely to be under selection during domestication, supporting the hypothesis that modification to seed size during domestication preferentially targeted genes for intrinsic seed size rather than genes associated with physiological factors involved in the carbohydrate supply and transport. Our results provide improved understanding of the complex genetic control of seed size and weight and the impact of domestication on these genes.
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Affiliation(s)
- Yongfu Tao
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
- *Correspondence: Yongfu Tao
| | - Emma S. Mace
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
- Department of Agriculture and Fisheries, Hermitage Research FacilityWarwick, QLD, Australia
- Emma S. Mace
| | | | - Alan Cruickshank
- Department of Agriculture and Fisheries, Hermitage Research FacilityWarwick, QLD, Australia
| | - Bradley C. Campbell
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - Xianrong Zhao
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
| | - Erik J. Van Oosterom
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandBrisbane, QLD, Australia
| | - Ian D. Godwin
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - Jose R. Botella
- School of Agriculture and Food Sciences, University of QueenslandBrisbane, QLD, Australia
| | - David R. Jordan
- Queensland Alliance for Agriculture and Food Innovation, University of QueenslandWarwick, QLD, Australia
- David R. Jordan
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16
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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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17
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Dai Y, Li W, An L. NMD mechanism and the functions of Upf proteins in plant. PLANT CELL REPORTS 2016; 35:5-15. [PMID: 26400685 DOI: 10.1007/s00299-015-1867-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/01/2015] [Accepted: 09/05/2015] [Indexed: 05/18/2023]
Abstract
Nonsense-mediated decay (NMD) mechanism, also called mRNA surveillance, is a universal mRNA degradation pathway in eukaryotes. Hundreds of genes can be regulated by NMD whether in single-celled or higher organisms. There have been many studies on NMD and NMD factors (Upf proteins) with regard to their crucial roles in mRNA decay, especially in mammals and yeast. However, research focusing on NMD in plant is still lacking compared to the research that has been dedicated to NMD in mammals and yeast. Even so, recent study has shown that NMD factors in Arabidopsis can provide resistance against biotic and abiotic stresses. This discovery and its associated developments have given plant NMD mechanism a new outlook and since then, more and more research has focused on this area. In this review, we focused mainly on the distinctive NMD micromechanism and functions of Upf proteins in plant with references to the role of mRNA surveillance in mammals and yeast. We also highlighted recent insights into the roles of premature termination codon location, trans-elements and functions of other NMD factors to emphasize the particularity of plant NMD. Furthermore, we also discussed conventional approaches and neoteric methods used in plant NMD researches.
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Affiliation(s)
- Yiming Dai
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China.
| | - Wenli Li
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China.
| | - Lijia An
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China.
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18
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Vexler K, Cymerman MA, Berezin I, Fridman A, Golani L, Lasnoy M, Saul H, Shaul O. The Arabidopsis NMD Factor UPF3 Is Feedback-Regulated at Multiple Levels and Plays a Role in Plant Response to Salt Stress. FRONTIERS IN PLANT SCIENCE 2016; 7:1376. [PMID: 27746786 PMCID: PMC5040709 DOI: 10.3389/fpls.2016.01376] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Accepted: 08/29/2016] [Indexed: 05/22/2023]
Abstract
Nonsense-mediated mRNA decay (NMD) is a eukaryotic RNA surveillance mechanism that degrades aberrant transcripts and controls the levels of many normal mRNAs. It was shown that balanced expression of the NMD factor UPF3 is essential for the maintenance of proper NMD homeostasis in Arabidopsis. UPF3 expression is controlled by a negative feedback loop that exposes UPF3 transcript to NMD. It was shown that the long 3' untranslated region (3' UTR) of UPF3 exposes its transcript to NMD. Long 3' UTRs that subject their transcripts to NMD were identified in several eukaryotic NMD factors. Interestingly, we show here that a construct that contains all the regulatory regions of the UPF3 gene except this long 3' UTR is also feedback-regulated by NMD. This indicates that UPF3 expression is feedback-regulated at multiple levels. UPF3 is constitutively expressed in different plant tissues, and its expression is equal in leaves of plants of different ages. This finding is in agreement with the possibility that UPF3 is ubiquitously operative in the Arabidopsis NMD pathway. Expression mediated by the regulatory regions of UPF3 is significantly induced by salt stress. We found that both a deficiency and a strong excess of UPF3 expression are detrimental to plant resistance to salt stress. This indicates that UPF3 plays a role in plant response to salt stress, and that balanced expression of the UPF3 gene is essential for coping with this stress.
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19
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Shaul O. Unique Aspects of Plant Nonsense-Mediated mRNA Decay. TRENDS IN PLANT SCIENCE 2015; 20:767-779. [PMID: 26442679 DOI: 10.1016/j.tplants.2015.08.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 08/17/2015] [Accepted: 08/20/2015] [Indexed: 05/20/2023]
Abstract
Nonsense-mediated mRNA Decay (NMD) is a eukaryotic quality-control mechanism that governs the stability of both aberrant and normal transcripts. Although plant and mammalian NMD share great similarity, they differ in certain mechanistic and regulatory aspects. Whereas SMG6 (from Caenorhabditis elegans 'suppressor with morphogenetic effect on genitalia')-catalyzed endonucleolytic cleavage is a prominent step in mammalian NMD, plant NMD targets are degraded by an SMG7-induced exonucleolytic pathway. Both mammalian and plant NMD are downregulated by stress, thereby enhancing the expression of defense response genes. However, the target genes and processes affected differ. Several plant and mammalian NMD factors are regulated by negative feedback-loops. However, while the loop regulating UPF3 (up-frameshift 3) expression in not vital for mammalian NMD, the sensitivity of UPF3 to NMD is crucial for the overall regulation of plant NMD.
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Affiliation(s)
- Orit Shaul
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
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20
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Zhu M, Chen G, Dong T, Wang L, Zhang J, Zhao Z, Hu Z. SlDEAD31, a Putative DEAD-Box RNA Helicase Gene, Regulates Salt and Drought Tolerance and Stress-Related Genes in Tomato. PLoS One 2015; 10:e0133849. [PMID: 26241658 PMCID: PMC4524616 DOI: 10.1371/journal.pone.0133849] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 07/02/2015] [Indexed: 01/04/2023] Open
Abstract
The DEAD-box RNA helicases are involved in almost every aspect of RNA metabolism, associated with diverse cellular functions including plant growth and development, and their importance in response to biotic and abiotic stresses is only beginning to emerge. However, none of DEAD-box genes was well characterized in tomato so far. In this study, we reported on the identification and characterization of two putative DEAD-box RNA helicase genes, SlDEAD30 and SlDEAD31 from tomato, which were classified into stress-related DEAD-box proteins by phylogenetic analysis. Expression analysis indicated that SlDEAD30 was highly expressed in roots and mature leaves, while SlDEAD31 was constantly expressed in various tissues. Furthermore, the expression of both genes was induced mainly in roots under NaCl stress, and SlDEAD31 mRNA was also increased by heat, cold, and dehydration. In stress assays, transgenic tomato plants overexpressing SlDEAD31 exhibited dramatically enhanced salt tolerance and slightly improved drought resistance, which were simultaneously demonstrated by significantly enhanced expression of multiple biotic and abiotic stress-related genes, higher survival rate, relative water content (RWC) and chlorophyll content, and lower water loss rate and malondialdehyde (MDA) production compared to wild-type plants. Collectively, these results provide a preliminary characterization of SlDEAD30 and SlDEAD31 genes in tomato, and suggest that stress-responsive SlDEAD31 is essential for salt and drought tolerance and stress-related gene regulation in plants.
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Affiliation(s)
- Mingku Zhu
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, People’s Republic of China
| | - Guoping Chen
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, People’s Republic of China
| | - Tingting Dong
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, People’s Republic of China
| | - Lingling Wang
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, People’s Republic of China
| | - Jianling Zhang
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, People’s Republic of China
| | - Zhiping Zhao
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, People’s Republic of China
| | - Zongli Hu
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, People’s Republic of China
- * E-mail:
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21
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Gloggnitzer J, Akimcheva S, Srinivasan A, Kusenda B, Riehs N, Stampfl H, Bautor J, Dekrout B, Jonak C, Jiménez-Gómez JM, Parker JE, Riha K. Nonsense-mediated mRNA decay modulates immune receptor levels to regulate plant antibacterial defense. Cell Host Microbe 2015; 16:376-90. [PMID: 25211079 DOI: 10.1016/j.chom.2014.08.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/29/2014] [Accepted: 08/24/2014] [Indexed: 12/15/2022]
Abstract
Nonsense-mediated mRNA decay (NMD) is a conserved eukaryotic RNA surveillance mechanism that degrades aberrant mRNAs. NMD impairment in Arabidopsis is linked to constitutive immune response activation and enhanced antibacterial resistance, but the underlying mechanisms are unknown. Here we show that NMD contributes to innate immunity in Arabidopsis by controlling the turnover of numerous TIR domain-containing, nucleotide-binding, leucine-rich repeat (TNL) immune receptor-encoding mRNAs. Autoimmunity resulting from NMD impairment depends on TNL signaling pathway components and can be triggered through deregulation of a single TNL gene, RPS6. Bacterial infection of plants causes host-programmed inhibition of NMD, leading to stabilization of NMD-regulated TNL transcripts. Conversely, constitutive NMD activity prevents TNL stabilization and impairs plant defense, demonstrating that host-regulated NMD contributes to disease resistance. Thus, NMD shapes plant innate immunity by controlling the threshold for activation of TNL resistance pathways.
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Affiliation(s)
- Jiradet Gloggnitzer
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 3, 1030 Vienna, Austria.
| | - Svetlana Akimcheva
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 3, 1030 Vienna, Austria
| | - Arunkumar Srinivasan
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
| | - Branislav Kusenda
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 3, 1030 Vienna, Austria
| | - Nina Riehs
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 3, 1030 Vienna, Austria
| | - Hansjörg Stampfl
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 3, 1030 Vienna, Austria
| | - Jaqueline Bautor
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
| | - Bettina Dekrout
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 3, 1030 Vienna, Austria
| | - Claudia Jonak
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 3, 1030 Vienna, Austria
| | - José M Jiménez-Gómez
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany; Institut Jean-Pierre Bourgin, UMR1318, INRA-AgroParisTech, 78000 Versailles, France
| | - Jane E Parker
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
| | - Karel Riha
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 3, 1030 Vienna, Austria; CEITEC, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic.
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22
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Degtiar E, Fridman A, Gottlieb D, Vexler K, Berezin I, Farhi R, Golani L, Shaul O. The feedback control of UPF3 is crucial for RNA surveillance in plants. Nucleic Acids Res 2015; 43:4219-35. [PMID: 25820429 PMCID: PMC4417159 DOI: 10.1093/nar/gkv237] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 03/06/2015] [Indexed: 11/24/2022] Open
Abstract
Nonsense-mediated-decay (NMD) is a eukaryotic RNA surveillance mechanism that controls the levels of both aberrant and normal transcripts. The regulation of this process is not well understood. The Arabidopsis NMD factor UPF3 is regulated by a negative feedback-loop that targets its own transcript for NMD. We investigated the functional significance of this control for the overall regulation of NMD in Arabidopsis. For this, we tested the ability of NMD-sensitive and -insensitive forms of UPF3, expressed under the control of UPF3 promoter, to complement NMD functionality in NMD-mutant plants and investigated their impact in wild-type (WT) plants. The sensitivity of UPF3 transcript to NMD was essential for efficient complementation of NMD in upf3 mutants. Upregulated UPF3 expression in WT plants resulted in over-degradation of certain transcripts and inhibited degradation of other transcripts. Our results demonstrate that, in contrast to mammalian cells, a delicate balance of UPF3 transcript levels by its feedback loop and by restriction of its transcription, are crucial for proper NMD regulation in Arabidopsis. Interestingly, the levels of many small-nucleolar-RNAs (snoRNAs) were decreased in upf1 and upf3 mutants and increased upon enhanced UPF3 expression. This suggests that proper snoRNA homeostasis in Arabidopsis depends on the integrity of the NMD pathway.
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Affiliation(s)
- Evgeniya Degtiar
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Adi Fridman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Dror Gottlieb
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Karina Vexler
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Irina Berezin
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Ronit Farhi
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Linoy Golani
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Orit Shaul
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
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23
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Rigby RE, Rehwinkel J. RNA degradation in antiviral immunity and autoimmunity. Trends Immunol 2015; 36:179-88. [PMID: 25709093 PMCID: PMC4358841 DOI: 10.1016/j.it.2015.02.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 02/02/2015] [Accepted: 02/02/2015] [Indexed: 01/09/2023]
Abstract
The nonsense-mediated decay (NMD) pathway defends cells against RNA virus invasion. NMD targets viral RNAs for degradation, including by the RNA exosome. Genetic deficiencies in NMD and RNA exosome components cause autoimmunity. NMD and the RNA exosome prevent aberrant activation of innate immune responses.
Post-transcriptional control determines the fate of cellular RNA molecules. Nonsense-mediated decay (NMD) provides quality control of mRNA, targeting faulty cellular transcripts for degradation by multiple nucleases including the RNA exosome. Recent findings have revealed a role for NMD in targeting viral RNA molecules, thereby restricting virus infection. Interestingly, NMD is also linked to immune responses at another level: mutations affecting the NMD or RNA exosome machineries cause chronic activation of defence programmes, resulting in autoimmune phenotypes. Here we place these observations in the context of other links between innate antiviral immunity and type I interferon mediated disease and examine two models: one in which expression or function of pathogen sensors is perturbed and one wherein host-derived RNA molecules with a propensity to activate such sensors accumulate.
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Affiliation(s)
- Rachel E Rigby
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Jan Rehwinkel
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, UK.
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24
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Uchiyama-Kadokura N, Murakami K, Takemoto M, Koyanagi N, Murota K, Naito S, Onouchi H. Polyamine-responsive ribosomal arrest at the stop codon of an upstream open reading frame of the AdoMetDC1 gene triggers nonsense-mediated mRNA decay in Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2014; 55:1556-67. [PMID: 24929422 DOI: 10.1093/pcp/pcu086] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
During mRNA translation, nascent peptides with certain specific sequences cause arrest of ribosomes that have synthesized themselves. In some cases, such ribosomal arrest is coupled with mRNA decay. In yeast, mRNA quality control systems have been shown to be involved in mRNA decay associated with ribosomal arrest. However, a link between ribosomal arrest and mRNA quality control systems has not been found in multicellular organisms. In this study, we aimed to explore the relationship between ribosomal arrest and mRNA decay in plants. For this purpose, we used an upstream open reading frame (uORF) of the Arabidopsis thaliana AdoMetDC1 gene, in which the uORF-encoded peptide is involved in polyamine-responsive translational repression of the main coding sequence. Our in vitro analyses revealed that the AdoMetDC1 uORF-encoded peptide caused ribosomal arrest at the uORF stop codon in response to polyamine. Using transgenic calli harboring an AdoMetDC1 uORF-containing reporter gene, we showed that polyamine promoted mRNA decay in a uORF sequence-dependent manner. These results suggest that the polyamine-responsive ribosomal arrest mediated by the uORF-encoded peptide is coupled with mRNA decay. Our results also showed that the polyamine-responsive acceleration of mRNA decay was compromised by defects in factors that are essential for nonsense-mediated mRNA decay (NMD), an mRNA quality control system that degrades mRNAs with premature stop codons, suggesting that NMD is involved in AdoMetDC1 uORF peptide-mediated mRNA decay. Collectively, these findings suggest that AdoMetDC1 uORF peptide-mediated ribosomal arrest at the uORF stop codon induces NMD.
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Affiliation(s)
- Naoko Uchiyama-Kadokura
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810 Japan Present address: Chifure Corporation, Kawagoe, 350-0833 Japan
| | - Karin Murakami
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan
| | - Mariko Takemoto
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan Present address: SRD Corporation, Chuo-ku, Tokyo, 104-0032 Japan
| | - Naoto Koyanagi
- Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan Present address: Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639 Japan
| | - Katsunori Murota
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810 Japan Present address: Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Sapporo, 062-8517 Japan
| | - Satoshi Naito
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810 Japan Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan
| | - Hitoshi Onouchi
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan
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25
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Khan A, Garbelli A, Grossi S, Florentin A, Batelli G, Acuna T, Zolla G, Kaye Y, Paul LK, Zhu JK, Maga G, Grafi G, Barak S. The Arabidopsis STRESS RESPONSE SUPPRESSOR DEAD-box RNA helicases are nucleolar- and chromocenter-localized proteins that undergo stress-mediated relocalization and are involved in epigenetic gene silencing. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 79:28-43. [PMID: 24724701 DOI: 10.1111/tpj.12533] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 04/03/2014] [Accepted: 04/08/2014] [Indexed: 05/03/2023]
Abstract
DEAD-box RNA helicases are involved in many aspects of RNA metabolism and in diverse biological processes in plants. Arabidopsis thaliana mutants of two DEAD-box RNA helicases, STRESS RESPONSE SUPPRESSOR1 (STRS1) and STRS2 were previously shown to exhibit tolerance to abiotic stresses and up-regulated stress-responsive gene expression. Here, we show that Arabidopsis STRS-overexpressing lines displayed a less tolerant phenotype and reduced expression of stress-induced genes confirming the STRSs as attenuators of Arabidopsis stress responses. GFP-STRS fusion proteins exhibited localization to the nucleolus, nucleoplasm and chromocenters and exhibited relocalization in response to abscisic acid (ABA) treatment and various stresses. This relocalization was reversed when stress treatments were removed. The STRS proteins displayed mis-localization in specific gene-silencing mutants and exhibited RNA-dependent ATPase and RNA-unwinding activities. In particular, STRS2 showed mis-localization in three out of four mutants of the RNA-directed DNA methylation (RdDM) pathway while STRS1 was mis-localized in the hd2c mutant that is defective in histone deacetylase activity. Furthermore, heterochromatic RdDM target loci displayed reduced DNA methylation and increased expression in the strs mutants. Taken together, our findings suggest that the STRS proteins are involved in epigenetic silencing of gene expression to bring about suppression of the Arabidopsis stress response.
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Affiliation(s)
- Asif Khan
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, 84990, Israel
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26
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Law SR, Narsai R, Whelan J. Mitochondrial biogenesis in plants during seed germination. Mitochondrion 2014; 19 Pt B:214-21. [PMID: 24727594 DOI: 10.1016/j.mito.2014.04.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Revised: 03/29/2014] [Accepted: 04/01/2014] [Indexed: 10/25/2022]
Abstract
Mitochondria occupy a central role in the eukaryotic cell. In addition to being major sources of cellular energy, mitochondria are also involved in a diverse range of functions including signalling, the synthesis of many essential organic compounds and a role in programmed cell death. The active proliferation and differentiation of mitochondria is termed mitochondrial biogenesis and necessitates the coordinated communication of mitochondrial status within an integrated cellular network. Two models of mitochondrial biogenesis have been defined previously, the growth and division model and the maturation model. The former describes the growth and division of pre-existing mature organelles through a form of binary fission, while the latter describes the propagation of mitochondria from structurally and biochemically simple promitochondrial structures that upon appropriate stimuli, mature into fully functional mitochondria. In the last decade, a number of studies have utilised seed germination in plants as a platform for the examination of the processes occurring during mitochondrial biogenesis. These studies have revealed many new aspects of the tightly regulated procession of events that define mitochondrial biogenesis during this period of rapid development. A model for mitochondrial biogenesis that supports the maturation of mitochondria from promitochondrial structures has emerged, where mitochondrial signalling plays a crucial role in the early steps of seed germination.
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Affiliation(s)
- Simon R Law
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Reena Narsai
- Department of Botany, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria, 3086, Australia
| | - James Whelan
- Department of Botany, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria, 3086, Australia.
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27
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Maldonado-Bonilla LD. Composition and function of P bodies in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2014; 5:201. [PMID: 24860588 PMCID: PMC4030149 DOI: 10.3389/fpls.2014.00201] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 04/24/2014] [Indexed: 05/20/2023]
Abstract
mRNA accumulation is tightly regulated by diverse molecular pathways. The identification and characterization of enzymes and regulatory proteins involved in controlling the fate of mRNA offers the possibility to broaden our understanding of posttranscriptional gene regulation. Processing bodies (P bodies, PB) are cytoplasmic protein complexes involved in degradation and translational arrest of mRNA. Composition and dynamics of these subcellular structures have been studied in animal systems, yeasts and in the model plant Arabidopsis. Their assembly implies the aggregation of specific factors related to decapping, deadenylation, and exoribonucleases that operate synchronously to regulate certain mRNA targets during development and adaptation to stress. Although the general function of PB along with the flow of genetic information is understood, several questions still remain open. This review summarizes data on the composition, potential molecular roles, and biological significance of PB and potentially related proteins in Arabidopsis.
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Affiliation(s)
- Luis D. Maldonado-Bonilla
- *Correspondence: Luis D. Maldonado-Bonilla, Laboratory of Plant Molecular Biology, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, San Luis Potosí 78216, Mexico e-mail:
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Kerényi F, Wawer I, Sikorski PJ, Kufel J, Silhavy D. Phosphorylation of the N- and C-terminal UPF1 domains plays a critical role in plant nonsense-mediated mRNA decay. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 76:836-48. [PMID: 24118551 DOI: 10.1111/tpj.12346] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 09/10/2013] [Accepted: 09/20/2013] [Indexed: 05/11/2023]
Abstract
Nonsense-mediated mRNA decay (NMD) is an essential quality control system that degrades aberrant transcripts containing premature termination codons and regulates the expression of several normal transcripts. Targets for NMD are selected during translational termination. If termination is slow, the UPF1 NMD factor binds the eRF3 protein of the termination complex and then recruits UPF2 and UPF3. Consequently, the UPF1-2-3 NMD complex induces SMG7-mediated degradation of the target mRNA. It is unknown how formation of the NMD complex and transcript degradation are linked in plants. Previously we have shown that the N- and C-terminal domains of UPF1 act redundantly and that the N-terminal domain is phosphorylated. To clarify the role of UPF1 phosphorylation in plant NMD, we generated UPF1 mutants and analyzed their phosphorylation status and the NMD competency of the mutants. We show that although several residues in the N-terminal domain of UPF1 are phosphorylated, only three phosphorylated amino acids, S3, S13 and T29, play a role in NMD. Moreover, we found that the C-terminal domain consists of redundant S/TQ-rich segments and that S1076 is involved in NMD. All NMD-relevant phosphorylation sites were in the S/TQ context. Co-localization and fluorescence resonance energy transfer-fluorescence lifetime imaging assays suggest that N-terminal and probably also C-terminal phosphorylated S/TQ residues are the binding platform for SMG7. Our data support the hypothesis that phosphorylation of UPF1 connects NMD complex formation and the SMG7-mediated target transcript degradation steps of NMD. SMG7 binds the phosphorylated S/TQ sites of the UPF1 component of the NMD complex, and then it induces the degradation of the NMD target.
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Affiliation(s)
- Farkas Kerényi
- Agricultural Biotechnology Center, Szent-Györgyi 4, H-2100, Gödöllõ, Hungary
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29
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Kanai M, Hayashi M, Kondo M, Nishimura M. The plastidic DEAD-box RNA helicase 22, HS3, is essential for plastid functions both in seed development and in seedling growth. PLANT & CELL PHYSIOLOGY 2013; 54:1431-40. [PMID: 23803517 DOI: 10.1093/pcp/pct091] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plants accumulate large amounts of storage products in seeds to provide an energy reserve and to supply nutrients for germination and post-germinative growth. Arabidopsis thaliana belongs to the Brassica family, and oil is the main storage product in Arabidopsis seeds. To elucidate the regulatory mechanisms of oil biosynthesis in seeds, we screened for high density seeds (heavy seed) that have a low oil content. HS3 (heavy seed 3) encodes the DEAD-box RNA helicase 22 that is localized to plastids. The triacylglycerol (TAG) content of hs3-1 seeds was 10% lower than that of wild-type (WT) seeds, while the protein content was unchanged. The hs3-1 plants displayed a pale-green phenotype in developing seeds and seedlings, but not in adult leaves. The HS3 expression level was high in developing seeds and seedlings, but was low in stems, rosette leaves and flowers. The plastid gene expression profile of WT developing seeds and seedlings differed from that of hs3-1 developing seeds and seedlings. The expression of several genes was reduced in developing hs3-1 seeds, including accD, a gene that encodes the β subunit of carboxyltransferase, which is one component of acetyl-CoA carboxylase in plastids. In contrast, no differences were observed between the expression profiles of WT and hs3-1 rosette leaves. These results show that HS3 is essential for proper mRNA accumulation of plastid genes during seed development and seedling growth, and suggest that HS3 ensures seed oil biosynthesis by maintaining plastid mRNA levels.
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Affiliation(s)
- Masatake Kanai
- Department of Cell Biology, National Institute for Basic Biology, Okazaki, 444-8585 Japan
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30
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Matia-González AM, Hasan A, Moe GH, Mata J, Rodríguez-Gabriel MA. Functional characterization of Upf1 targets in Schizosaccharomyces pombe. RNA Biol 2013; 10:1057-65. [PMID: 23619768 DOI: 10.4161/rna.24569] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a highly conserved mechanism of mRNA degradation. NMD eliminates mRNAs containing premature termination codons (PTCs), preventing the production of truncated proteins with possible deleterious effects. However, there is mounting evidence that NMD factors, like Upf1, Upf2 and Upf3, participate in general regulation of gene expression, affecting the expression of genes lacking PTCs. We have used the fission yeast Schizosaccharomyces pombe to identify mRNAs directly regulated by NMD. Using a combination of genetic and biochemical approaches, we have defined a population of fission yeast mRNAs specifically regulated by Upf1. We show that other components of the Upf complex, Upf2 and Upf3, are required for binding of Upf1 to its RNA targets and for the proper response of fission yeast to oxidative stress. Finally, we investigated the physiological importance of this phenomenon, and demonstrate that the Upf1-dependent downregulation of some of its direct targets is necessary for normal resistance to oxidative stress.
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31
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Sasaki K, Kim MH, Imai R. Arabidopsis COLD SHOCK DOMAIN PROTEIN 2 is a negative regulator of cold acclimation. THE NEW PHYTOLOGIST 2013; 198:95-102. [PMID: 23323758 DOI: 10.1111/nph.12118] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 11/27/2012] [Indexed: 06/01/2023]
Abstract
Bacterial cold shock proteins (CSPs) act as RNA chaperones that destabilize mRNA secondary structures at low temperatures. Bacterial CSPs are composed solely of a nucleic acid-binding domain termed the cold shock domain (CSD). Plant CSD proteins contain an auxiliary domain in addition to the CSD but also show RNA chaperone activity. However, their biological functions are poorly understood. We examined Arabidopsis COLD SHOCK DOMAIN PROTEIN 2 (AtCSP2) using overexpressing and mutant lines. A double mutant, with reduced AtCSP2 and no AtCSP4, showed higher freezing tolerance than the wild-type when cold-acclimated. The increase in freezing tolerance was associated with up-regulation of CBF transcription factors and their downstream genes. By contrast, overexpression of AtCSP2 resulted in decreased freezing tolerance when cold-acclimated. In addition, late flowering and shorter siliques were observed in the overexpressing lines. AtCSP2 negatively regulates freezing tolerance and is partially redundant with its closest paralog, AtCSP4.
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Affiliation(s)
- Kentaro Sasaki
- Hokkaido Agriculture Research Center, National Agriculture and Food Research Organization, Hitsujigaoka 1, Toyohira-ku, Sapporo, 062-8555, Japan
- Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, 060-8589, Japan
| | - Myung-Hee Kim
- Hokkaido Agriculture Research Center, National Agriculture and Food Research Organization, Hitsujigaoka 1, Toyohira-ku, Sapporo, 062-8555, Japan
| | - Ryozo Imai
- Hokkaido Agriculture Research Center, National Agriculture and Food Research Organization, Hitsujigaoka 1, Toyohira-ku, Sapporo, 062-8555, Japan
- Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, 060-8589, Japan
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32
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Rayson S, Ashworth M, de Torres Zabala M, Grant M, Davies B. The salicylic acid dependent and independent effects of NMD in plants. PLANT SIGNALING & BEHAVIOR 2012; 7:1434-7. [PMID: 22990450 PMCID: PMC3548866 DOI: 10.4161/psb.21960] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In eukaryotes, nonsense-mediated mRNA decay (NMD) targets aberrant and selected non-aberrant mRNAs for destruction. A recent screen for mRNAs showing increased abundance in Arabidopsis NMD-deficient mutants revealed that most are associated with the salicylic acid (SA)-mediated defense pathway. mRNAs with conserved peptide upstream open reading frames (CpuORFs or CuORFs) are hugely overrepresented among the smaller class of NMD-regulated transcripts not associated with SA. Here we show that the common phenotypes observed in Arabidopsis NMD mutants are SA-dependent, whereas the upregulation of CpuORF-containing transcripts in NMD mutants is independent of SA. We speculate that CpuORFs could allow the conditional targeting of mRNAs for destruction using the NMD pathway.
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Affiliation(s)
- Samantha Rayson
- Centre for Plant Sciences; Faculty of Biological Sciences; University of Leeds; Leeds, UK
| | - Mary Ashworth
- Centre for Plant Sciences; Faculty of Biological Sciences; University of Leeds; Leeds, UK
| | - Marta de Torres Zabala
- Biosciences; College of Life and Environmental Sciences; Geoffrey Pope; University of Exeter; Exeter, UK
| | - Murray Grant
- Biosciences; College of Life and Environmental Sciences; Geoffrey Pope; University of Exeter; Exeter, UK
| | - Brendan Davies
- Centre for Plant Sciences; Faculty of Biological Sciences; University of Leeds; Leeds, UK
- Correspondence to: Brendan Davies,
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33
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Syed NH, Kalyna M, Marquez Y, Barta A, Brown JW. Alternative splicing in plants--coming of age. TRENDS IN PLANT SCIENCE 2012; 17:616-23. [PMID: 22743067 PMCID: PMC3466422 DOI: 10.1016/j.tplants.2012.06.001] [Citation(s) in RCA: 336] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 05/30/2012] [Accepted: 06/02/2012] [Indexed: 05/18/2023]
Abstract
More than 60% of intron-containing genes undergo alternative splicing (AS) in plants. This number will increase when AS in different tissues, developmental stages, and environmental conditions are explored. Although the functional impact of AS on protein complexity is still understudied in plants, recent examples demonstrate its importance in regulating plant processes. AS also regulates transcript levels and the link with nonsense-mediated decay and generation of unproductive mRNAs illustrate the need for both transcriptional and AS data in gene expression analyses. AS has influenced the evolution of the complex networks of regulation of gene expression and variation in AS contributed to adaptation of plants to their environment and therefore will impact strategies for improving plant and crop phenotypes.
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Affiliation(s)
- Naeem H. Syed
- Division of Plant Sciences, University of Dundee at the James Hutton Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK
| | - Maria Kalyna
- Max F. Perutz Laboratories, Medical University of Vienna, Dr Bohr-Gasse 9/3, A-1030 Vienna, Austria
| | - Yamile Marquez
- Max F. Perutz Laboratories, Medical University of Vienna, Dr Bohr-Gasse 9/3, A-1030 Vienna, Austria
| | - Andrea Barta
- Max F. Perutz Laboratories, Medical University of Vienna, Dr Bohr-Gasse 9/3, A-1030 Vienna, Austria
| | - John W.S. Brown
- Division of Plant Sciences, University of Dundee at the James Hutton Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK
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34
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Riehs-Kearnan N, Gloggnitzer J, Dekrout B, Jonak C, Riha K. Aberrant growth and lethality of Arabidopsis deficient in nonsense-mediated RNA decay factors is caused by autoimmune-like response. Nucleic Acids Res 2012; 40:5615-24. [PMID: 22379136 PMCID: PMC3384318 DOI: 10.1093/nar/gks195] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 02/09/2012] [Accepted: 02/10/2012] [Indexed: 12/22/2022] Open
Abstract
Nonsense-mediated RNA decay (NMD) is an evolutionarily conserved RNA quality control mechanism that eliminates transcripts containing nonsense mutations. NMD has also been shown to affect the expression of numerous genes, and inactivation of this pathway is lethal in higher eukaryotes. However, despite relatively detailed knowledge of the molecular basis of NMD, our understanding of its physiological functions is still limited and the underlying causes of lethality are unknown. In this study, we examined the importance of NMD in plants by analyzing an allelic series of Arabidopsis thaliana mutants impaired in the core NMD components SMG7 and UPF1. We found that impaired NMD elicits a pathogen defense response which appears to be proportional to the extent of NMD deficiency. We also demonstrate that developmental aberrations and lethality of the strong smg7 and upf1 alleles are caused by constitutive pathogen response upregulation. Disruption of pathogen signaling suppresses the lethality of the upf1-3 null allele and growth defects associated with SMG7 dysfunction. Interestingly, infertility and abortive meiosis observed in smg7 mutants is not coupled with impaired NMD suggesting a broader function of SMG7 in cellular metabolism. Taken together, our results uncover a major physiological consequence of NMD deficiency in Arabidopsis and revealed multifaceted roles of SMG7 in plant growth and development.
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Affiliation(s)
| | | | | | | | - Karel Riha
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria
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35
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Rayson S, Arciga-Reyes L, Wootton L, De Torres Zabala M, Truman W, Graham N, Grant M, Davies B. A role for nonsense-mediated mRNA decay in plants: pathogen responses are induced in Arabidopsis thaliana NMD mutants. PLoS One 2012; 7:e31917. [PMID: 22384098 PMCID: PMC3284524 DOI: 10.1371/journal.pone.0031917] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 01/15/2012] [Indexed: 11/19/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a conserved mechanism that targets aberrant mRNAs for destruction. NMD has also been found to regulate the expression of large numbers of genes in diverse organisms, although the biological role for this is unclear and few evolutionarily conserved targets have been identified. Expression analyses of three Arabidopsis thaliana lines deficient in NMD reveal that the vast majority of NMD-targeted transcripts are associated with response to pathogens. Congruently, NMD mutants, in which these transcripts are elevated, confer partial resistance to Pseudomonas syringae. These findings suggest a biological rationale for the regulation of gene expression by NMD in plants and suggest that manipulation of NMD could offer a new approach for crop protection. Amongst the few non-pathogen responsive NMD-targeted genes, one potential NMD targeted signal, the evolutionarily conserved upstream open reading frame (CuORF), was found to be hugely over-represented, raising the possibility that this feature could be used to target specific physiological mRNAs for control by NMD.
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Affiliation(s)
- Samantha Rayson
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Luis Arciga-Reyes
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Lucie Wootton
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | | | - William Truman
- School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Neil Graham
- Nottingham Arabidopsis Stock Centre, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
| | - Murray Grant
- School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Brendan Davies
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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36
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Shi C, Baldwin IT, Wu J. Arabidopsis plants having defects in nonsense-mediated mRNA decay factors UPF1, UPF2, and UPF3 show photoperiod-dependent phenotypes in development and stress responses. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2012; 54:99-114. [PMID: 22353561 DOI: 10.1111/j.1744-7909.2012.01093.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Nonsense-mediated mRNA decay (NMD) is an important mRNA quality surveillance pathway in all eukaryotes that eliminates aberrant mRNAs derived from various sources. Three NMD factor proteins, UPF1, UPF2, and UPF3 are required for the NMD process and were found to be also involved in certain stress responses in mammalian and yeast cells. Using Arabidopsis thaliana mutants of UPF1 and UPF3 and UPF2-silenced lines (irUPF2), we examined the involvement of UPF1, UPF2, and UPF3 in development and in response to stresses, wounding and infection by Pseudomonas syringae pv. tomato strain DC3000. Under the long (16 h) photoperiod condition, Arabidopsis having a defect in NMD factors exhibited altered morphologies of various organs, disturbed homeostasis of wounding-induced jasmonic acid and pathogen-elicited salicylic acid, and abnormal wounding- and methyl jasmonate-induced changes in the transcript levels of two defense-related genes, LOX2 and VSP2. Importantly, when plants were cultivated under the short (10 h) photoperiod condition, mutants of UPF1 and UPF3 and irUPF2 showed smaller differences from the wild-type plants in growth and stress-induced responses. These data suggest a complex regulatory network, likely composed of light signaling and NMD factor-mediated pathways, in influencing plant development and adaption to environmental stresses.
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Affiliation(s)
- Chuan Shi
- Department of Medical Engineering and Biotechnology, University of Applied Sciences, Jena, 07745 Germany
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37
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Cirulli ET, Heinzen EL, Dietrich FS, Shianna KV, Singh A, Maia JM, Goedert JJ, Goldstein DB. A whole-genome analysis of premature termination codons. Genomics 2011; 98:337-42. [PMID: 21803148 PMCID: PMC3282586 DOI: 10.1016/j.ygeno.2011.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 07/02/2011] [Accepted: 07/14/2011] [Indexed: 11/18/2022]
Abstract
We sequenced the genomes of ten unrelated individuals and identified heterozygous stop codon-gain variants in protein-coding genes: we then sequenced their transcriptomes and assessed the expression levels of the stop codon-gain alleles. An ANOVA showed statistically significant differences between their expression levels (p=4×10(-16)). This difference was almost entirely accounted for by whether the stop codon-gain variant had a second, non-protein-truncating function in or near an alternate transcript: stop codon-gains without alternate functions were generally not found in the cDNA (p=3×10(-5)). Additionally, stop codon-gain variants in two intronless genes were not expressed, an unexpected outcome given previous studies. In this study, stop codon-gain variants were either well expressed in all individuals or were never expressed. Our finding that stop codon-gain variants were generally expressed only when they had an alternate function suggests that most naturally occurring stop codon-gain variants in protein-coding genes are either not transcribed or have their transcripts destroyed.
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Affiliation(s)
- Elizabeth T. Cirulli
- Center for Human Genome Variation, Duke University School of Medicine, Box 91009, Durham, 27708, USA
| | - Erin L. Heinzen
- Center for Human Genome Variation, Duke University School of Medicine, Box 91009, Durham, 27708, USA
| | - Fred S. Dietrich
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Research Drive, Durham, NC 27710, USA
| | - Kevin V. Shianna
- Center for Human Genome Variation, Duke University School of Medicine, Box 91009, Durham, 27708, USA
| | - Abanish Singh
- Center for Human Genome Variation, Duke University School of Medicine, Box 91009, Durham, 27708, USA
| | - Jessica M. Maia
- Center for Human Genome Variation, Duke University School of Medicine, Box 91009, Durham, 27708, USA
| | - James J. Goedert
- Infections & Immunoepidemiology Branch, Division of Cancer Epidemiology and Genetics, US National Cancer Institutes of Health, 6120 Executive Boulevard, Rockville, 20852, USA
| | - David B. Goldstein
- Center for Human Genome Variation, Duke University School of Medicine, Box 91009, Durham, 27708, USA
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Delhi P, Queiroz R, Inchaustegui D, Carrington M, Clayton C. Is there a classical nonsense-mediated decay pathway in trypanosomes? PLoS One 2011; 6:e25112. [PMID: 21957477 PMCID: PMC3177853 DOI: 10.1371/journal.pone.0025112] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 08/24/2011] [Indexed: 11/18/2022] Open
Abstract
In many eukaryotes, messenger RNAs with premature termination codons are destroyed by a process called "nonsense-mediated decay", which requires the RNA helicase Upf1 and also, usually, an interacting factor, Upf2. Recognition of premature termination codons may rely on their distance from either a splice site or the polyadenylation site, and long 3'-untranslated regions can trigger mRNA decay. The protist Trypanosoma brucei relies heavily on mRNA degradation to determine mRNA levels, and 3'-untranslated regions play a major role in control of mRNA decay. We show here that trypanosomes have a homologue of Upf1, TbUPF1, which interacts with TbUPF2 and (in an RNA-dependent fashion) with poly(A) binding protein 1, PABP1. Introduction of a premature termination codon in either an endogenous gene or a reporter gene decreased mRNA abundance, as expected for nonsense-mediated decay, but a dependence of this effect on TbUPF1 could not be demonstrated, and depletion of TbUPF1 by over 95% had no effect on parasite growth or the mRNA transcriptome. Further investigations of the reporter mRNA revealed that increases in open reading frame length tended to increase mRNA abundance. In contrast, inhibition of translation, either using 5'-secondary structures or by lengthening the 5'-untranslated region, usually decreased reporter mRNA abundance. Meanwhile, changing the length of the 3'-untranslated region had no consistent effect on mRNA abundance. We suggest that in trypanosomes, translation per se may inhibit mRNA decay, and interactions with multiple RNA-binding proteins preclude degradation based on 3'-untranslated region length alone.
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Affiliation(s)
- Praveen Delhi
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Hedielberg, Germany
- * E-mail: (PD); (CC)
| | - Rafael Queiroz
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Hedielberg, Germany
| | - Diana Inchaustegui
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Hedielberg, Germany
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Hedielberg, Germany
- * E-mail: (PD); (CC)
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Xu J, Chua NH. Processing bodies and plant development. CURRENT OPINION IN PLANT BIOLOGY 2011; 14:88-93. [PMID: 21075046 PMCID: PMC3042721 DOI: 10.1016/j.pbi.2010.10.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 10/15/2010] [Accepted: 10/16/2010] [Indexed: 05/22/2023]
Abstract
Processing bodies (P-bodies) contain RNA-protein complexes linked to cytoplasmic RNA decay pathways including mRNA decapping, nonsense-mediated decay (NMD) and small RNA-mediated decay. Plants deficient in P-body components display severe developmental perturbations, suggesting that these cytoplasmic bodies play important roles in regulating gene expression during plant development. Here, we summarize recent progress in the genetic dissection of P-body components and their roles in translational repression and mRNA decapping.
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Affiliation(s)
- Jun Xu
- Laboratory of Plant Molecular Biology, Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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40
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Benkovics AH, Nyikó T, Mérai Z, Silhavy D, Bisztray GD. Functional analysis of the grapevine paralogs of the SMG7 NMD factor using a heterolog VIGS-based gene depletion-complementation system. PLANT MOLECULAR BIOLOGY 2011; 75:277-90. [PMID: 21234790 DOI: 10.1007/s11103-010-9726-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 12/24/2010] [Indexed: 05/23/2023]
Abstract
Nonsense-mediated mRNA decay (NMD) is a eukaryotic quality control system that identifies and eliminates transcripts having a premature translation termination codon (PTC). NMD is also involved in the control of several wild-type mRNAs. The NMD core machinery consists of three highly conserved NMD factors (UPF1, UPF2 and UPF3) and at least one less conserved 14-3-3-like domain containing protein (SMG7). A PTC is identified by UPF factors, and then SMG7 triggers rapid transcript decay. UPF factors are generally encoded by a single gene, whereas SMG7 has duplicated several times during evolution. Recently it was reported that the plant SMG7 is autoregulated through NMD and that SMG7 has two relatively divergent paralogs in dicots, SMG7 and SMG7L. In mammals all three SMG7 related genes (SMG5, SMG6 and SMG7) are essential in NMD, so we hypothesized that in plants the SMG7 and SMG7L duplicates may also play distinct roles in NMD. To test this possibility, we have analyzed the evolution and the function of plant SMG7 homologs. We show that SMG7L is not required for plant NMD. Interestingly, we found that the grapevine and poplar genomes contain two quite divergent SMG7 paralogs which may have derived from an ancient duplication event. Using heterolog depletion/complementation assays we demonstrate that both grapevine SMG7 copies retained the complete NMD activity and both of them are under NMD control, whilst SMG7L has lost NMD activity and NMD control.
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41
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Vicente-Crespo M, Palacios IM. Nonsense-mediated mRNA decay and development: shoot the messenger to survive? Biochem Soc Trans 2010; 38:1500-5. [PMID: 21118115 PMCID: PMC3432441 DOI: 10.1042/bst0381500] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
NMD (nonsense-mediated mRNA decay) is a surveillance mechanism that degrades transcripts containing nonsense mutations, preventing the translation of potentially harmful truncated proteins. Although the mechanistic details of NMD are gradually being understood, the physiological role of this RNA surveillance pathway still remains largely unknown. The core NMD genes Upf1 (up-frameshift suppressor 1) and Upf2 are essential for animal viability in the fruitfly, mouse and zebrafish. These findings may reflect an important role for NMD during animal development. Alternatively, the lethal phenotypes of upf1 and upf2 mutants might be due to their function in NMD-independent processes. In the present paper, we describe the phenotypes observed when the NMD factors are mutated in various organisms, and discuss findings that might shed light on the function of NMD in cellular growth and development of an organism.
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Affiliation(s)
- Marta Vicente-Crespo
- Division of Biology, University of California San Diego, 9500 Gilman Drive, Bonner Hall 3230, La Jolla, CA 92093-0322, U.S.A
| | - Isabel M. Palacios
- Zoology Department, University of Cambridge, Downing Street, Cambridge CB2 3EJ, U.K
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42
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Abstract
NMD (nonsense-mediated mRNA decay) belongs to the best-studied mRNA surveillance systems of the cell, limiting the synthesis of truncated and potentially harmful proteins on the one hand and playing an initially unexpected role in the regulation of global gene expression on the other hand. In the present review, we briefly discuss the factors involved in NMD, the different models proposed for the recognition of PTCs (premature termination codons), the diverse physiological roles of NMD, the involvement of this surveillance pathway in disease and the current strategies for medical treatment of PTC-related diseases.
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43
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Cottage A, Mott EK, Kempster JA, Gray JC. The Arabidopsis plastid-signalling mutant gun1 (genomes uncoupled1) shows altered sensitivity to sucrose and abscisic acid and alterations in early seedling development. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:3773-86. [PMID: 20605896 PMCID: PMC2921207 DOI: 10.1093/jxb/erq186] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 06/02/2010] [Accepted: 06/04/2010] [Indexed: 05/18/2023]
Abstract
Developing seedlings of the Arabidopsis gun1 (genomes uncoupled1) mutant, which is defective in retrograde plastid-to-nucleus signalling, show several previously unrecognized mutant phenotypes. gun1 seedlings accumulated less anthocyanin than wild-type seedlings when grown in the presence of 2% (w/v) sucrose, due to lower amounts of transcripts of early anthocyanin biosynthesis genes in gun1. Norflurazon and lincomycin, which induce retrograde signalling, further decreased the anthocyanin content of sucrose-treated seedlings, and altered the temporal pattern of anthocyanin accumulation. Lincomycin treatment altered the spatial pattern of sucrose-induced anthocyanin accumulation, suggesting that plastids provide information for the regulation of anthocyanin biosynthesis in Arabidopsis seedlings. The temporal pattern of accumulation of LHCB1 transcripts differed between wild-type and gun1 seedlings, and gun1 seedlings were more sensitive to sucrose suppression of LHCB1 transcript accumulation than wild-type seedlings. Growth and development of gun1 seedlings was more sensitive to exogenous 2% sucrose than wild-type seedlings and, in the presence of lincomycin, cotyledon expansion was enhanced in gun1 seedlings compared to the wild type. gun1 seedlings were more sensitive than wild-type seedlings to the inhibition of seedling growth and development by abscisic acid. These observations clearly implicate GUN1 and plastid signalling in the regulation of seedling development and anthocyanin biosynthesis, and indicate a complex interplay between sucrose and plastid signalling pathways.
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Affiliation(s)
| | | | | | - John C. Gray
- To whom correspondence should be addressed: E-mail:
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Wen J, Brogna S. Splicing-dependent NMD does not require the EJC in Schizosaccharomyces pombe. EMBO J 2010; 29:1537-51. [PMID: 20360683 PMCID: PMC2876954 DOI: 10.1038/emboj.2010.48] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2009] [Accepted: 03/04/2010] [Indexed: 12/04/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a translation-linked process that destroys mRNAs with premature translation termination codons (PTCs). In mammalian cells, NMD is also linked to pre-mRNA splicing, usually PTCs trigger strong NMD only when positioned upstream of at least one intron. The exon junction complex (EJC) is believed to mediate the link between splicing and NMD in these systems. Here, we report that in Schizosaccharomyces pombe splicing also enhances NMD, but against the EJC model prediction, an intron stimulated NMD regardless of whether it is positioned upstream or downstream of the PTC and EJC components are not required. Still the effect of splicing seems to be direct-we have found that the important NMD determinant is the proximity of an intron to the PTC, not just the occurrence of splicing. On the basis of these results, we propose a new model to explain how splicing could affect NMD.
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Affiliation(s)
- Jikai Wen
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK
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Nicholson P, Yepiskoposyan H, Metze S, Zamudio Orozco R, Kleinschmidt N, Mühlemann O. Nonsense-mediated mRNA decay in human cells: mechanistic insights, functions beyond quality control and the double-life of NMD factors. Cell Mol Life Sci 2010; 67:677-700. [PMID: 19859661 PMCID: PMC11115722 DOI: 10.1007/s00018-009-0177-1] [Citation(s) in RCA: 254] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 09/16/2009] [Accepted: 10/06/2009] [Indexed: 12/16/2022]
Abstract
Nonsense-mediated decay is well known by the lucid definition of being a RNA surveillance mechanism that ensures the speedy degradation of mRNAs containing premature translation termination codons. However, as we review here, NMD is far from being a simple quality control mechanism; it also regulates the stability of many wild-type transcripts. We summarise the abundance of research that has characterised each of the NMD factors and present a unified model for the recognition of NMD substrates. The contentious issue of how and where NMD occurs is also discussed, particularly with regard to P-bodies and SMG6-driven endonucleolytic degradation. In recent years, the discovery of additional functions played by several of the NMD factors has further complicated the picture. Therefore, we also review the reported roles of UPF1, SMG1 and SMG6 in other cellular processes.
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Affiliation(s)
- Pamela Nicholson
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012, Bern, Switzerland
| | - Hasmik Yepiskoposyan
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012, Bern, Switzerland
| | - Stefanie Metze
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012, Bern, Switzerland
| | - Rodolfo Zamudio Orozco
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012, Bern, Switzerland
| | - Nicole Kleinschmidt
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012, Bern, Switzerland
| | - Oliver Mühlemann
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012, Bern, Switzerland
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Palusa SG, Reddy ASN. Extensive coupling of alternative splicing of pre-mRNAs of serine/arginine (SR) genes with nonsense-mediated decay. THE NEW PHYTOLOGIST 2010; 185:83-9. [PMID: 19863731 DOI: 10.1111/j.1469-8137.2009.03065.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In Arabidopsis, pre-mRNAs encoding serine/arginine (SR) proteins, key regulators of constitutive and alternative splicing, are extensively alternatively spliced. In seedlings, 13 SR genes are alternatively spliced to generate 75 transcripts, of which 53 contain a premature termination codon (PTC). However, it is not known if any of the PTC-containing splice variants are the targets of nonsense-mediated decay (NMD) and if there is any link between NMD and the abundance of functional transcripts. Here, we analyzed the abundances of all splice variants for each alternatively spliced gene in an Arabidopsis mutant that lacks UPF3, one of the core components of NMD machinery, to determine if the PTC-containing transcripts are degraded by NMD. Our results show that about half of the 53 splice variants with a PTC are the targets of degradation by NMD. The accumulation of PTC-containing transcripts resulted in concomitant reduction in the amount of functional transcript. These results show widespread coupling of alternative splicing with NMD in the SR gene family, suggesting a strong link between unproductive splicing and the abundance of functional transcripts.
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Affiliation(s)
- Saiprasad G Palusa
- Department of Biology, Program in Molecular Plant Biology, Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
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Saul H, Elharrar E, Gaash R, Eliaz D, Valenci M, Akua T, Avramov M, Frankel N, Berezin I, Gottlieb D, Elazar M, David-Assael O, Tcherkas V, Mizrachi K, Shaul O. The upstream open reading frame of the Arabidopsis AtMHX gene has a strong impact on transcript accumulation through the nonsense-mediated mRNA decay pathway. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 60:1031-42. [PMID: 19754518 DOI: 10.1111/j.1365-313x.2009.04021.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Approximately 20% of plant genes possess upstream open-reading frames (uORFs). The effect of uORFs on gene expression has mainly been studied at the translational level. Very little is known about the impact of plant uORFs on transcript content through the nonsense-mediated mRNA decay (NMD) pathway, which degrades transcripts bearing premature termination codons (PTCs). Here we examine the impact of the uORF of the Arabidopsis AtMHX gene on transcript accumulation. The suggestion that this uORF exposes transcripts containing it to NMD is supported by (i) the increase in transcript levels upon eliminating the uORF from constructs containing it, (ii) experiments with a modified uORF-peptide, which excluded peptide-specific degradation mechanisms, (iii) the increase in levels of the native AtMHX transcript upon treatment with cycloheximide, which inhibits translation and blocks NMD, and (iv) the sensitivity of transcripts containing the uORF of AtMHX to the presence of introns. We also showed that introns can increase NMD efficiency not only in transcripts having relatively short 3' untranslated regions (UTRs), but also in uORF-containing transcripts. AtMHX transcript levels were almost unaltered in mutants of the NMD factors UPF3 and UPF1. Possible reasons, including the existence of a NMD-compensatory mechanism, are discussed. Interestingly, the levels of UPF3 transcript were higher in upf1 mutants, suggesting a compensatory mechanism that links weak function of the NMD machinery to increased expression of UPF3. Our findings highlight that uORFs, which are abundant in plants, can not only inhibit translation but also strongly affect transcript accumulation.
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Affiliation(s)
- Helen Saul
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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Abstract
Unlike maize and wheat, where artificial selection is associated with an almost uniform increase in seed or grain size, domesticated rice exhibits dramatic phenotypic diversity for grain size and shape. Here we clone and characterize GS3, an evolutionarily important gene controlling grain size in rice. We show that GS3 is highly expressed in young panicles in both short- and long-grained varieties but is not expressed in leaves or panicles after flowering, and we use genetic transformation to demonstrate that the dominant allele for short grain complements the long-grain phenotype. An association study revealed that a C to A mutation in the second exon of GS3 (A allele) was associated with enhanced grain length in Oryza sativa but was absent from other Oryza species. Linkage disequilibrium (LD) was elevated and there was a 95.7% reduction in nucleotide diversity (theta(pi)) across the gene in accessions carrying the A allele, suggesting positive selection for long grain. Haplotype analysis traced the origin of the long-grain allele to a Japonica-like ancestor and demonstrated introgression into the Indica gene pool. This study indicates a critical role for GS3 in defining the seed morphologies of modern subpopulations of O. sativa and enhances the potential for genetic manipulation of grain size in rice.
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Linder P, Owttrim GW. Plant RNA helicases: linking aberrant and silencing RNA. TRENDS IN PLANT SCIENCE 2009; 14:344-52. [PMID: 19446493 DOI: 10.1016/j.tplants.2009.03.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 03/11/2009] [Accepted: 03/17/2009] [Indexed: 05/06/2023]
Abstract
RNA helicases are ATPases that are capable of rearranging RNA and ribonucleoprotein (RNP) structure, and they can potentially function in any aspect of RNA metabolism. The RNA helicase gene family of plant genomes is larger and more diverse than genome families observed in other systems and provides an ideal model for investigation of the physiological importance of RNA secondary structure rearrangement in plant development. Numerous plant RNA helicases are associated with a variety of physiological functions, but this review will focus on the thirteen RNA helicases associated with the metabolism of aberrant and silencing RNAs. The results emphasize the crucial role RNA helicase activity has in the regulation of mRNA quality control and gene expression in plant development.
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Affiliation(s)
- Patrick Linder
- Department of Microbiology and Molecular Medicine, CMU, 1 Rue Michel Servet, CH-1211 Geneve 4, Switzerland
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50
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Nonsense-mediated mRNA decay effectors are essential for zebrafish embryonic development and survival. Mol Cell Biol 2009; 29:3517-28. [PMID: 19414594 DOI: 10.1128/mcb.00177-09] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The nonsense-mediated mRNA decay (NMD) pathway promotes rapid degradation of mRNAs containing premature translation termination codons (PTCs or nonsense codons), preventing accumulation of potentially detrimental truncated proteins. In metazoa, seven genes (upf1, upf2, upf3, smg1, smg5, smg6, and smg7) have been identified as essential for NMD; here we show that the zebrafish genome encodes orthologs of upf1, upf2, smg1, and smg5 to smg7 and two upf3 paralogs. We also show that Upf1 is required for degradation of PTC-containing mRNAs in zebrafish embryos. Moreover, its depletion has a severe impact on embryonic development, early patterning, and viability. Similar phenotypes are observed in Upf2-, Smg5-, or Smg6-depleted embryos, suggesting that zebrafish embryogenesis requires an active NMD pathway. Using cultured cells, we demonstrate that the ability of a PTC to trigger NMD is strongly stimulated by downstream exon-exon boundaries. Thus, as in mammals and plants but in contrast to invertebrates and fungi, NMD is coupled to splicing in zebrafish. Our results together with previous studies show that NMD effectors are essential for vertebrate embryogenesis and suggest that the coupling of splicing and NMD has been maintained in vertebrates but lost in fungi and invertebrates.
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