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Yu Q, Tungsuchat-Huang T, Ioannou A, Barkan A, Maliga P. Posttranscriptional tuning of gene expression over a large dynamic range in synthetic tobacco chloroplast operons. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 119:2437-2449. [PMID: 39031552 DOI: 10.1111/tpj.16930] [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: 03/06/2024] [Revised: 06/02/2024] [Accepted: 07/01/2024] [Indexed: 07/22/2024]
Abstract
Achieving optimally balanced gene expression within synthetic operons requires regulatory elements capable of providing a spectrum of expression levels. In this study, we investigate the expression of gfp reporter gene in tobacco chloroplasts, guided by variants of the plastid atpH 5' UTR, which harbors a binding site for PPR10, a protein that activates atpH at the posttranscriptional level. Our findings reveal that endogenous tobacco PPR10 confers distinct levels of reporter activation when coupled with the tobacco and maize atpH 5' UTRs in different design contexts. Notably, high GFP expression was not coupled to the stabilization of monocistronic gfp transcripts in dicistronic reporter lines, adding to the evidence that PPR10 activates translation via a mechanism that is independent of its stabilization of monocistronic transcripts. Furthermore, the incorporation of a tRNA upstream of the UTR nearly abolishes gfp mRNA (and GFP protein), presumably by promoting such rapid RNA cleavage and 5' exonucleolytic degradation that PPR10 had insufficient time to bind and protect gfp RNA, resulting in a substantial reduction in GFP accumulation. When combined with a mutant atpH 5' UTR, the tRNA leads to an exceptionally low level of transgene expression. Collectively, this approach allows for tuning of reporter gene expression across a wide range, spanning from a mere 0.02-25% of the total soluble cellular protein. These findings highlight the potential of employing cis-elements from heterologous species and expand the toolbox available for plastid synthetic biology applications requiring multigene expression at varying levels.
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Affiliation(s)
- Qiguo Yu
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, 08854, USA
| | | | - Alexander Ioannou
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, 08854, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, 97403, USA
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, 08854, USA
- Department of Plant Biology, Rutgers University, New Brunswick, New Jersey, 08901, USA
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2
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Chaux F, Jarrige D, Rodrigues-Azevedo M, Bujaldon S, Caspari OD, Ozawa SI, Drapier D, Vallon O, Choquet Y, de Vitry C. Chloroplast ATP synthase biogenesis requires peripheral stalk subunits AtpF and ATPG and stabilization of atpE mRNA by OPR protein MDE1. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:1582-1599. [PMID: 37824282 DOI: 10.1111/tpj.16448] [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: 05/17/2023] [Revised: 08/15/2023] [Accepted: 08/21/2023] [Indexed: 10/14/2023]
Abstract
Chloroplast ATP synthase contains subunits of plastid and nuclear genetic origin. To investigate the coordinated biogenesis of this complex, we isolated novel ATP synthase mutants in the green alga Chlamydomonas reinhardtii by screening for high light sensitivity. We report here the characterization of mutants affecting the two peripheral stalk subunits b and b', encoded respectively by the atpF and ATPG genes, and of three independent mutants which identify the nuclear factor MDE1, required to stabilize the chloroplast-encoded atpE mRNA. Whole-genome sequencing revealed a transposon insertion in the 3'UTR of ATPG while mass spectrometry shows a small accumulation of functional ATP synthase in this knock-down ATPG mutant. In contrast, knock-out ATPG mutants, obtained by CRISPR-Cas9 gene editing, fully prevent ATP synthase function and accumulation, as also observed in an atpF frame-shift mutant. Crossing ATP synthase mutants with the ftsh1-1 mutant of the major thylakoid protease identifies AtpH as an FTSH substrate, and shows that FTSH significantly contributes to the concerted accumulation of ATP synthase subunits. In mde1 mutants, the absence of atpE transcript fully prevents ATP synthase biogenesis and photosynthesis. Using chimeric atpE genes to rescue atpE transcript accumulation, we demonstrate that MDE1, a novel octotricopeptide repeat (OPR) protein, genetically targets the atpE 5'UTR. In the perspective of the primary endosymbiosis (~1.5 Gy), the recruitment of MDE1 to its atpE target exemplifies a nucleus/chloroplast interplay that evolved rather recently, in the ancestor of the CS clade of Chlorophyceae, ~300 My ago.
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Affiliation(s)
- Frédéric Chaux
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Domitille Jarrige
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Marcio Rodrigues-Azevedo
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Sandrine Bujaldon
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Oliver D Caspari
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Shin-Ichiro Ozawa
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Dominique Drapier
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Olivier Vallon
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Yves Choquet
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Catherine de Vitry
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
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3
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An H, Ke X, Li L, Liu Y, Yuan S, Wang Q, Hou X, Zhao J. ALBINO EMBRYO AND SEEDLING is required for RNA splicing and chloroplast homeostasis in Arabidopsis. PLANT PHYSIOLOGY 2023; 193:483-501. [PMID: 37311175 DOI: 10.1093/plphys/kiad341] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 05/03/2023] [Accepted: 05/07/2023] [Indexed: 06/15/2023]
Abstract
Pentatricopeptide repeat (PPR) proteins form a large protein family and have diverse functions in plant development. Here, we identified an ALBINO EMBRYO AND SEEDLING (AES) gene that encodes a P-type PPR protein expressed in various tissues, especially the young leaves of Arabidopsis (Arabidopsis thaliana). Its null mutant aes exhibited a collapsed chloroplast membrane system, reduced pigment content and photosynthetic activity, decreased transcript levels of PEP (plastid-encoded polymerase)-dependent chloroplast genes, and defective RNA splicing. Further work revealed that AES could directly bind to psbB-psbT, psbH-petB, rps8-rpl36, clpP, ycf3, and ndhA in vivo and in vitro and that the splicing efficiencies of these genes and the expression levels of ycf3, ndhA, and cis-tron psbB-psbT-psbH-petB-petD decreased dramatically, leading to defective PSI, PSII, and Cyt b6f in aes. Moreover, AES could be transported into the chloroplast stroma via the TOC-TIC channel with the assistance of Tic110 and cpSRP54 and may recruit HCF244, SOT1, and CAF1 to participate in the target RNA process. These findings suggested that AES is an essential protein for the assembly of photosynthetic complexes, providing insights into the splicing of psbB operon (psbB-psbT-psbH-petB-petD), ycf3, and ndhA, as well as maintaining chloroplast homeostasis.
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Affiliation(s)
- Hongqiang An
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Xiaolong Ke
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Lu Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Yantong Liu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Sihui Yuan
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Qiuyu Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Xin Hou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, 430072 Wuhan, China
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4
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Jian Y, Chen X, Sun K, Liu Z, Cheng D, Cao J, Liu J, Cheng X, Wu L, Zhang F, Luo Y, Hahn M, Ma Z, Yin Y. SUMOylation regulates pre-mRNA splicing to overcome DNA damage in fungi. THE NEW PHYTOLOGIST 2023; 237:2298-2315. [PMID: 36539920 DOI: 10.1111/nph.18692] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
Pathogenic fungi are subject to DNA damage stress derived from host immune responses during infection. Small ubiquitin-like modifier (SUMO) modification and precursor (pre)-mRNA splicing are both involved in DNA damage response (DDR). However, the mechanisms of how SUMOylation and splicing coordinated in DDR remain largely unknown. Combining with biochemical analysis, RNA-Seq method, and biological analysis, we report that SUMO pathway participates in DDR and virulence in Fusarium graminearum, a causal agent of Fusarium head blight of cereal crops world-wide. Interestingly, a key transcription factor FgSR is SUMOylated upon DNA damage stress. SUMOylation regulates FgSR nuclear-cytoplasmic partitioning and its phosphorylation by FgMec1, and promotes its interaction with chromatin remodeling complex SWI/SNF for activating the expression of DDR-related genes. Moreover, the SWI/SNF complex was found to further recruit splicing-related NineTeen Complex, subsequently modulates pre-mRNA splicing during DDR. Our findings reveal a novel function of SUMOylation in DDR by regulating a transcription factor to orchestrate gene expression and pre-mRNA splicing to overcome DNA damage during the infection of F. graminearum, which advances the understanding of the delicate regulation of DDR by SUMOylation in pathogenic fungi, and extends the knowledge of cooperation of SUMOylation and pre-mRNA splicing in DDR in eukaryotes.
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Affiliation(s)
- Yunqing Jian
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Xia Chen
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Kewei Sun
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Zunyong Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Danni Cheng
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Jie Cao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Jianzhao Liu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Xiaofei Cheng
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of Chinese Education Ministry, College of Agriculture, Northeast Agricultural University, Harbin, 150030, China
| | - Liang Wu
- Institute of Crop Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Feng Zhang
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuming Luo
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China
| | - Matthias Hahn
- Department of Biology, University of Kaiserslautern, PO Box 3049, 67653, Kaiserslautern, Germany
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yanni Yin
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
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5
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Scaltsoyiannes V, Corre N, Waltz F, Giegé P. Types and Functions of Mitoribosome-Specific Ribosomal Proteins across Eukaryotes. Int J Mol Sci 2022; 23:ijms23073474. [PMID: 35408834 PMCID: PMC8998825 DOI: 10.3390/ijms23073474] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 02/04/2023] Open
Abstract
Mitochondria are key organelles that combine features inherited from their bacterial endosymbiotic ancestor with traits that arose during eukaryote evolution. These energy producing organelles have retained a genome and fully functional gene expression machineries including specific ribosomes. Recent advances in cryo-electron microscopy have enabled the characterization of a fast-growing number of the low abundant membrane-bound mitochondrial ribosomes. Surprisingly, mitoribosomes were found to be extremely diverse both in terms of structure and composition. Still, all of them drastically increased their number of ribosomal proteins. Interestingly, among the more than 130 novel ribosomal proteins identified to date in mitochondria, most of them are composed of a-helices. Many of them belong to the nuclear encoded super family of helical repeat proteins. Here we review the diversity of functions and the mode of action held by the novel mitoribosome proteins and discuss why these proteins that share similar helical folds were independently recruited by mitoribosomes during evolution in independent eukaryote clades.
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Affiliation(s)
- Vassilis Scaltsoyiannes
- CNRS, Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, 67084 Strasbourg, France; (V.S.); (N.C.)
| | - Nicolas Corre
- CNRS, Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, 67084 Strasbourg, France; (V.S.); (N.C.)
| | - Florent Waltz
- CNRS, Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, 67084 Strasbourg, France; (V.S.); (N.C.)
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Munich, Germany
- Correspondence: (F.W.); (P.G.); Tel.: +33-3-6715-5363 (P.G.); Fax: +33-3-8861-4442 (P.G.)
| | - Philippe Giegé
- CNRS, Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, 67084 Strasbourg, France; (V.S.); (N.C.)
- Correspondence: (F.W.); (P.G.); Tel.: +33-3-6715-5363 (P.G.); Fax: +33-3-8861-4442 (P.G.)
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6
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Bernath-Levin K, Schmidberger J, Honkanen S, Gutmann B, Sun YK, Pullakhandam A, Colas des Francs-Small C, Bond CS, Small I. Cofactor-independent RNA editing by a synthetic S-type PPR protein. Synth Biol (Oxf) 2022; 7:ysab034. [PMID: 35128071 PMCID: PMC8809517 DOI: 10.1093/synbio/ysab034] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 12/24/2022] Open
Abstract
Pentatricopeptide repeat (PPR) proteins are RNA-binding proteins that are attractive tools for RNA processing in synthetic biology applications given their modular structure and ease of design. Several distinct types of motifs have been described from natural PPR proteins, but almost all work so far with synthetic PPR proteins has focused on the most widespread P-type motifs. We have investigated synthetic PPR proteins based on tandem repeats of the more compact S-type PPR motif found in plant organellar RNA editing factors and particularly prevalent in the lycophyte Selaginella. With the aid of a novel plate-based screening method, we show that synthetic S-type PPR proteins are easy to design and bind with high affinity and specificity and are functional in a wide range of pH, salt and temperature conditions. We find that they outperform a synthetic P-type PPR scaffold in many situations. We designed an S-type editing factor to edit an RNA target in E. coli and demonstrate that it edits effectively without requiring any additional cofactors to be added to the system. These qualities make S-type PPR scaffolds ideal for developing new RNA processing tools.
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Affiliation(s)
- Kalia Bernath-Levin
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Jason Schmidberger
- School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Suvi Honkanen
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Bernard Gutmann
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Yueming Kelly Sun
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Anuradha Pullakhandam
- School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Catherine Colas des Francs-Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Charles S Bond
- School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
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7
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Waltz F, Salinas-Giegé T, Englmeier R, Meichel H, Soufari H, Kuhn L, Pfeffer S, Förster F, Engel BD, Giegé P, Drouard L, Hashem Y. How to build a ribosome from RNA fragments in Chlamydomonas mitochondria. Nat Commun 2021; 12:7176. [PMID: 34887394 PMCID: PMC8660880 DOI: 10.1038/s41467-021-27200-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/08/2021] [Indexed: 01/12/2023] Open
Abstract
Mitochondria are the powerhouse of eukaryotic cells. They possess their own gene expression machineries where highly divergent and specialized ribosomes, named hereafter mitoribosomes, translate the few essential messenger RNAs still encoded by mitochondrial genomes. Here, we present a biochemical and structural characterization of the mitoribosome in the model green alga Chlamydomonas reinhardtii, as well as a functional study of some of its specific components. Single particle cryo-electron microscopy resolves how the Chlamydomonas mitoribosome is assembled from 13 rRNA fragments encoded by separate non-contiguous gene pieces. Additional proteins, mainly OPR, PPR and mTERF helical repeat proteins, are found in Chlamydomonas mitoribosome, revealing the structure of an OPR protein in complex with its RNA binding partner. Targeted amiRNA silencing indicates that these ribosomal proteins are required for mitoribosome integrity. Finally, we use cryo-electron tomography to show that Chlamydomonas mitoribosomes are attached to the inner mitochondrial membrane via two contact points mediated by Chlamydomonas-specific proteins. Our study expands our understanding of mitoribosome diversity and the various strategies these specialized molecular machines adopt for membrane tethering.
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Affiliation(s)
- Florent Waltz
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, 33600, Pessac, France
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Thalia Salinas-Giegé
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France
| | - Robert Englmeier
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Herrade Meichel
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France
| | - Heddy Soufari
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, 33600, Pessac, France
| | - Lauriane Kuhn
- Plateforme protéomique Strasbourg Esplanade FRC1589 du CNRS, Université de Strasbourg, 67084, Strasbourg, France
| | - Stefan Pfeffer
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany
| | - Friedrich Förster
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Benjamin D Engel
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
- Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Philippe Giegé
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France.
| | - Laurence Drouard
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France.
| | - Yaser Hashem
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, 33600, Pessac, France.
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8
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Kim M, Schulz V, Brings L, Schoeller T, Kühn K, Vierling E. mTERF18 and ATAD3 are required for mitochondrial nucleoid structure and their disruption confers heat tolerance in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2021; 232:2026-2042. [PMID: 34482561 DOI: 10.1111/nph.17717] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/23/2021] [Indexed: 05/27/2023]
Abstract
Mitochondria play critical roles in generating ATP through oxidative phosphorylation (OXPHOS) and produce both damaging and signaling reactive oxygen species (ROS). They have reduced genomes that encode essential subunits of the OXPHOS machinery. Mitochondrial Transcription tERmination Factor-related (mTERF) proteins are involved in organelle gene expression, interacting with organellar DNA or RNA. We previously found that mutations in Arabidopsis thaliana mTERF18/SHOT1 enable plants to better tolerate heat and oxidative stresses, presumably due to low ROS production and reduced oxidative damage. Here we discover that shot1 mutants have greatly reduced OXPHOS complexes I and IV and reveal that suppressor of hot1-4 1 (SHOT1) binds DNA and localizes to mitochondrial nucleoids, which are disrupted in shot1. Furthermore, three homologues of animal ATPase family AAA domain-containing protein 3 (ATAD3), which is involved in mitochondrial nucleoid organization, were identified as SHOT1-interacting proteins. Importantly, disrupting ATAD3 function disrupts nucleoids, reduces accumulation of complex I, and enhances heat tolerance, as is seen in shot1 mutants. Our data link nucleoid organization to OXPHOS biogenesis and suggest that the common defects in shot1 mutants and ATAD3-disrupted plants lead to critical changes in mitochondrial metabolism and signaling that result in plant heat tolerance.
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Affiliation(s)
- Minsoo Kim
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Vincent Schulz
- Department of Life Sciences, Institute of Biology, Humboldt-Universität zu Berlin, 10099, Berlin, Germany
| | - Lea Brings
- Department of Life Sciences, Institute of Biology, Humboldt-Universität zu Berlin, 10099, Berlin, Germany
| | - Theresa Schoeller
- Department of Plant Physiology, Institute of Biology, Martin-Luther-Universität Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Kristina Kühn
- Department of Life Sciences, Institute of Biology, Humboldt-Universität zu Berlin, 10099, Berlin, Germany
- Department of Plant Physiology, Institute of Biology, Martin-Luther-Universität Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Elizabeth Vierling
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA, 01003, USA
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9
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Shahar N, Elman T, Williams-Carrier R, Ben-Zvi O, Yacoby I, Barkan A. Use of plant chloroplast RNA-binding proteins as orthogonal activators of chloroplast transgenes in the green alga Chlamydomonas reinhardtii. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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10
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DeTar RA, Barahimipour R, Manavski N, Schwenkert S, Höhner R, Bölter B, Inaba T, Meurer J, Zoschke R, Kunz HH. Loss of inner-envelope K+/H+ exchangers impairs plastid rRNA maturation and gene expression. THE PLANT CELL 2021; 33:2479-2505. [PMID: 34235544 PMCID: PMC8364240 DOI: 10.1093/plcell/koab123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/30/2021] [Indexed: 05/08/2023]
Abstract
The inner-envelope K+ EFFLUX ANTIPORTERS (KEA) 1 and 2 are critical for chloroplast development, ion homeostasis, and photosynthesis. However, the mechanisms by which changes in ion flux across the envelope affect organelle biogenesis remained elusive. Chloroplast development requires intricate coordination between the nuclear genome and the plastome. Many mutants compromised in plastid gene expression (PGE) display a virescent phenotype, that is delayed greening. The phenotypic appearance of Arabidopsis thaliana kea1 kea2 double mutants fulfills this criterion, yet a link to PGE has not been explored. Here, we show that a simultaneous loss of KEA1 and KEA2 results in maturation defects of the plastid ribosomal RNAs. This may be caused by secondary structure changes of rRNA transcripts and concomitant reduced binding of RNA-processing proteins, which we documented in the presence of skewed ion homeostasis in kea1 kea2. Consequently, protein synthesis and steady-state levels of plastome-encoded proteins remain low in mutants. Disturbance in PGE and other signs of plastid malfunction activate GENOMES UNCOUPLED 1-dependent retrograde signaling in kea1 kea2, resulting in a dramatic downregulation of GOLDEN2-LIKE transcription factors to halt expression of photosynthesis-associated nuclear-encoded genes (PhANGs). PhANG suppression delays the development of fully photosynthesizing kea1 kea2 chloroplasts, probably to avoid progressing photo-oxidative damage. Overall, our results reveal that KEA1/KEA2 function impacts plastid development via effects on RNA-metabolism and PGE.
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Affiliation(s)
- Rachael Ann DeTar
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
| | - Rouhollah Barahimipour
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Nikolay Manavski
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Serena Schwenkert
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Ricarda Höhner
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
| | - Bettina Bölter
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Takehito Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Jörg Meurer
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Hans-Henning Kunz
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
- Author for correspondence:
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11
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Wietrzynski W, Traverso E, Wollman FA, Wostrikoff K. The state of oligomerization of Rubisco controls the rate of synthesis of the Rubisco large subunit in Chlamydomonas reinhardtii. THE PLANT CELL 2021; 33:1706-1727. [PMID: 33625514 PMCID: PMC8254502 DOI: 10.1093/plcell/koab061] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/12/2021] [Indexed: 05/22/2023]
Abstract
Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) is present in all photosynthetic organisms and is a key enzyme for photosynthesis-driven life on Earth. Its most prominent form is a hetero-oligomer in which small subunits (SSU) stabilize the core of the enzyme built from large subunits (LSU), yielding, after a chaperone-assisted multistep assembly process, an LSU8SSU8 hexadecameric holoenzyme. Here we use Chlamydomonas reinhardtii and a combination of site-directed mutants to dissect the multistep biogenesis pathway of Rubisco in vivo. We identify assembly intermediates, in two of which LSU are associated with the RAF1 chaperone. Using genetic and biochemical approaches we further unravel a major regulation process during Rubisco biogenesis, in which LSU translation is controlled by its ability to assemble with the SSU, via the mechanism of control by epistasy of synthesis (CES). Altogether this leads us to propose a model whereby the last assembly intermediate, an LSU8-RAF1 complex, provides the platform for SSU binding to form the Rubisco enzyme, and when SSU is not available, converts to a key regulatory form that exerts negative feedback on the initiation of LSU translation.
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Affiliation(s)
- Wojciech Wietrzynski
- Sorbonne Université, CNRS, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, 75005 Paris, France
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Eleonora Traverso
- Sorbonne Université, CNRS, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, 75005 Paris, France
| | - Francis-André Wollman
- Sorbonne Université, CNRS, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, 75005 Paris, France
| | - Katia Wostrikoff
- Sorbonne Université, CNRS, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, 75005 Paris, France
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12
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Hollin T, Jaroszewski L, Stajich JE, Godzik A, Le Roch KG. Identification and phylogenetic analysis of RNA binding domain abundant in apicomplexans or RAP proteins. Microb Genom 2021; 7. [PMID: 33656416 PMCID: PMC8190603 DOI: 10.1099/mgen.0.000541] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The RNA binding domain abundant in apicomplexans (RAP) is a protein domain identified in a diverse group of proteins, called RAP proteins, many of which have been shown to be involved in RNA binding. To understand the expansion and potential function of the RAP proteins, we conducted a hidden Markov model based screen among the proteomes of 54 eukaryotes, 17 bacteria and 12 archaea. We demonstrated that the domain is present in closely and distantly related organisms with particular expansions in Alveolata and Chlorophyta, and are not unique to Apicomplexa as previously believed. All RAP proteins identified can be decomposed into two parts. In the N-terminal region, the presence of variable helical repeats seems to participate in the specific targeting of diverse RNAs, while the RAP domain is mostly identified in the C-terminal region and is highly conserved across the different phylogenetic groups studied. Several conserved residues defining the signature motif could be crucial to ensure the function(s) of the RAP proteins. Modelling of RAP domains in apicomplexan parasites confirmed an ⍺/β structure of a restriction endonuclease-like fold. The phylogenetic trees generated from multiple alignment of RAP domains and full-length proteins from various distantly related eukaryotes indicated a complex evolutionary history of this family. We further discuss these results to assess the potential function of this protein family in apicomplexan parasites.
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Affiliation(s)
- Thomas Hollin
- Department of Molecular, Cell and Systems Biology, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Lukasz Jaroszewski
- Department of Biomedical Sciences, University of California Riverside School of Medicine, 900 University Avenue, Riverside, CA 92521, USA
| | - Jason E. Stajich
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Adam Godzik
- Department of Biomedical Sciences, University of California Riverside School of Medicine, 900 University Avenue, Riverside, CA 92521, USA
| | - Karine G. Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
- *Correspondence: Karine G. Le Roch,
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13
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Wobbe L. The Molecular Function of Plant mTERFs as Key Regulators of Organellar Gene Expression. PLANT & CELL PHYSIOLOGY 2021; 61:2004-2017. [PMID: 33067620 DOI: 10.1093/pcp/pcaa132] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 09/25/2020] [Indexed: 05/27/2023]
Abstract
The protein family of mTERFs (mitochondrial transcription termination factors) was initially studied in mammalian and insect mitochondria before the first Arabidopsis mTERF mutant was characterized. More than 10 years of research on the function of plant mTERFs in the flowering plants Arabidopsis thaliana, Zea mays and the green microalga Chlamydomonas reinhardtii has since highlighted that mTERFs are key regulators of organellar gene expression (OGE) in mitochondria and in chloroplasts. Additional functions to be fulfilled by plant mTERFs (e.g. splicing) and the fact that the expression of two organellar genomes had to be facilitated have led to a massive expansion of the plant mTERF portfolio compared to that found in mammals. Plant mTERFs are implicated in all steps of OGE ranging from the modulation of transcription to the maturation of tRNAs and hence translation. Furthermore, being regulators of OGE, mTERFs are required for a successful long-term acclimation to abiotic stress, retrograde signaling and interorganellar communication. Here, I review the recent progress in the elucidation of molecular mTERF functions.
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Affiliation(s)
- Lutz Wobbe
- Algae Biotechnology & Bioenergy Group, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Universit�tsstrasse 27, Bielefeld 33615, Germany
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14
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Méteignier LV, Ghandour R, Zimmerman A, Kuhn L, Meurer J, Zoschke R, Hammani K. Arabidopsis mTERF9 protein promotes chloroplast ribosomal assembly and translation by establishing ribonucleoprotein interactions in vivo. Nucleic Acids Res 2021; 49:1114-1132. [PMID: 33398331 PMCID: PMC7826268 DOI: 10.1093/nar/gkaa1244] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/07/2020] [Accepted: 12/13/2020] [Indexed: 12/13/2022] Open
Abstract
The mitochondrial transcription termination factor proteins are nuclear-encoded nucleic acid binders defined by degenerate tandem helical-repeats of ∼30 amino acids. They are found in metazoans and plants where they localize in organelles. In higher plants, the mTERF family comprises ∼30 members and several of these have been linked to plant development and response to abiotic stress. However, knowledge of the molecular basis underlying these physiological effects is scarce. We show that the Arabidopsis mTERF9 protein promotes the accumulation of the 16S and 23S rRNAs in chloroplasts, and interacts predominantly with the 16S rRNA in vivo and in vitro. Furthermore, mTERF9 is found in large complexes containing ribosomes and polysomes in chloroplasts. The comprehensive analysis of mTERF9 in vivo protein interactome identified many subunits of the 70S ribosome whose assembly is compromised in the null mterf9 mutant, putative ribosome biogenesis factors and CPN60 chaperonins. Protein interaction assays in yeast revealed that mTERF9 directly interact with these proteins. Our data demonstrate that mTERF9 integrates protein-protein and protein-RNA interactions to promote chloroplast ribosomal assembly and translation. Besides extending our knowledge of mTERF functional repertoire in plants, these findings provide an important insight into the chloroplast ribosome biogenesis.
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Affiliation(s)
- Louis-Valentin Méteignier
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Rabea Ghandour
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Aude Zimmerman
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Lauriane Kuhn
- Plateforme protéomique Strasbourg Esplanade FRC1589 du CNRS, Université de Strasbourg, 15 rue René Descartes, 67084 Strasbourg, France
| | - Jörg Meurer
- Plant Sciences, Faculty of Biology, Ludwig-Maximilians-University Munich, Großhaderner Street 2-4, 82152 Planegg-Martinsried, Germany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Kamel Hammani
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
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15
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Arabidopsis Mitochondrial Transcription Termination Factor mTERF2 Promotes Splicing of Group IIB Introns. Cells 2021; 10:cells10020315. [PMID: 33546419 PMCID: PMC7913559 DOI: 10.3390/cells10020315] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 12/21/2022] Open
Abstract
Plastid gene expression (PGE) is essential for chloroplast biogenesis and function and, hence, for plant development. However, many aspects of PGE remain obscure due to the complexity of the process. A hallmark of nuclear-organellar coordination of gene expression is the emergence of nucleus-encoded protein families, including nucleic-acid binding proteins, during the evolution of the green plant lineage. One of these is the mitochondrial transcription termination factor (mTERF) family, the members of which regulate various steps in gene expression in chloroplasts and/or mitochondria. Here, we describe the molecular function of the chloroplast-localized mTERF2 in Arabidopsis thaliana. The complete loss of mTERF2 function results in embryo lethality, whereas directed, microRNA (amiR)-mediated knockdown of MTERF2 is associated with perturbed plant development and reduced chlorophyll content. Moreover, photosynthesis is impaired in amiR-mterf2 plants, as indicated by reduced levels of photosystem subunits, although the levels of the corresponding messenger RNAs are not affected. RNA immunoprecipitation followed by RNA sequencing (RIP-Seq) experiments, combined with whole-genome RNA-Seq, RNA gel-blot, and quantitative RT-PCR analyses, revealed that mTERF2 is required for the splicing of the group IIB introns of ycf3 (intron 1) and rps12.
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16
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Westrich LD, Gotsmann VL, Herkt C, Ries F, Kazek T, Trösch R, Armbruster L, Mühlenbeck JS, Ramundo S, Nickelsen J, Finkemeier I, Wirtz M, Storchová Z, Räschle M, Willmund F. The versatile interactome of chloroplast ribosomes revealed by affinity purification mass spectrometry. Nucleic Acids Res 2021; 49:400-415. [PMID: 33330923 PMCID: PMC7797057 DOI: 10.1093/nar/gkaa1192] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/19/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
In plant cells, chloroplast gene expression is predominantly controlled through post-transcriptional regulation. Such fine-tuning is vital for precisely orchestrating protein complex assembly as for the photosynthesis machinery and for quickly responding to environmental changes. While regulation of chloroplast protein synthesis is of central importance, little is known about the degree and nature of the regulatory network, mainly due to challenges associated with the specific isolation of transient ribosome interactors. Here, we established a ribosome affinity purification method, which enabled us to broadly uncover putative ribosome-associated proteins in chloroplasts. Endogenously tagging of a protein of the large or small subunit revealed not only interactors of the holo complex, but also preferential interactors of the two subunits. This includes known canonical regulatory proteins as well as several new proteins belonging to the categories of protein and RNA regulation, photosystem biogenesis, redox control and metabolism. The sensitivity of the here applied screen was validated for various transiently interacting proteins. We further provided evidence for the existence of a ribosome-associated Nα-acetyltransferase in chloroplasts and its ability to acetylate substrate proteins at their N-terminus. The broad set of ribosome interactors underscores the potential to regulate chloroplast gene expression on the level of protein synthesis.
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Affiliation(s)
- Lisa Désirée Westrich
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Vincent Leon Gotsmann
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Claudia Herkt
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Fabian Ries
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Tanja Kazek
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Raphael Trösch
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Laura Armbruster
- Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Jens Stephan Mühlenbeck
- Plant Physiology, Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 7, 48149 Münster, Germany
| | - Silvia Ramundo
- Department of Biochemistry and Biophysics, University of California, 600 16th St, N316, San Francisco, CA 94143, USA
| | - Jörg Nickelsen
- Department of Molecular Plant Science, University of Munich, Grosshaderner-Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Iris Finkemeier
- Plant Physiology, Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 7, 48149 Münster, Germany
| | - Markus Wirtz
- Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Zuzana Storchová
- Molecular Genetics, University of Kaiserslautern, Paul-Ehrlich-Str. 24, 67663 Kaiserslautern, Germany
| | - Markus Räschle
- Molecular Genetics, University of Kaiserslautern, Paul-Ehrlich-Str. 24, 67663 Kaiserslautern, Germany
| | - Felix Willmund
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
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17
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Teramoto T, Kaitany KJ, Kakuta Y, Kimura M, Fierke CA, Hall TMT. Pentatricopeptide repeats of protein-only RNase P use a distinct mode to recognize conserved bases and structural elements of pre-tRNA. Nucleic Acids Res 2020; 48:11815-11826. [PMID: 32719843 DOI: 10.1093/nar/gkaa627] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 07/07/2020] [Accepted: 07/14/2020] [Indexed: 02/07/2023] Open
Abstract
Pentatricopeptide repeat (PPR) motifs are α-helical structures known for their modular recognition of single-stranded RNA sequences with each motif in a tandem array binding to a single nucleotide. Protein-only RNase P 1 (PRORP1) in Arabidopsis thaliana is an endoribonuclease that uses its PPR domain to recognize precursor tRNAs (pre-tRNAs) as it catalyzes removal of the 5'-leader sequence from pre-tRNAs with its NYN metallonuclease domain. To gain insight into the mechanism by which PRORP1 recognizes tRNA, we determined a crystal structure of the PPR domain in complex with yeast tRNAPhe at 2.85 Å resolution. The PPR domain of PRORP1 bound to the structurally conserved elbow of tRNA and recognized conserved structural features of tRNAs using mechanisms that are different from the established single-stranded RNA recognition mode of PPR motifs. The PRORP1 PPR domain-tRNAPhe structure revealed a conformational change of the PPR domain upon tRNA binding and moreover demonstrated the need for pronounced overall flexibility in the PRORP1 enzyme conformation for substrate recognition and catalysis. The PRORP1 PPR motifs have evolved strategies for protein-tRNA interaction analogous to tRNA recognition by the RNA component of ribonucleoprotein RNase P and other catalytic RNAs, indicating convergence on a common solution for tRNA substrate recognition.
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Affiliation(s)
- Takamasa Teramoto
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.,Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Kipchumba J Kaitany
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yoshimitsu Kakuta
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Makoto Kimura
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Carol A Fierke
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.,Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.,Departments of Chemistry and Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Traci M Tanaka Hall
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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18
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Oberleitner L, Poschmann G, Macorano L, Schott-Verdugo S, Gohlke H, Stühler K, Nowack ECM. The Puzzle of Metabolite Exchange and Identification of Putative Octotrico Peptide Repeat Expression Regulators in the Nascent Photosynthetic Organelles of Paulinella chromatophora. Front Microbiol 2020; 11:607182. [PMID: 33329499 PMCID: PMC7729196 DOI: 10.3389/fmicb.2020.607182] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022] Open
Abstract
The endosymbiotic acquisition of mitochondria and plastids more than one billion years ago was central for the evolution of eukaryotic life. However, owing to their ancient origin, these organelles provide only limited insights into the initial stages of organellogenesis. The cercozoan amoeba Paulinella chromatophora contains photosynthetic organelles-termed chromatophores-that evolved from a cyanobacterium ∼100 million years ago, independently from plastids in plants and algae. Despite the more recent origin of the chromatophore, it shows tight integration into the host cell. It imports hundreds of nucleus-encoded proteins, and diverse metabolites are continuously exchanged across the two chromatophore envelope membranes. However, the limited set of chromatophore-encoded solute transporters appears insufficient for supporting metabolic connectivity or protein import. Furthermore, chromatophore-localized biosynthetic pathways as well as multiprotein complexes include proteins of dual genetic origin, suggesting that mechanisms evolved that coordinate gene expression levels between chromatophore and nucleus. These findings imply that similar to the situation in mitochondria and plastids, also in P. chromatophora nuclear factors evolved that control metabolite exchange and gene expression in the chromatophore. Here we show by mass spectrometric analyses of enriched insoluble protein fractions that, unexpectedly, nucleus-encoded transporters are not inserted into the chromatophore inner envelope membrane. Thus, despite the apparent maintenance of its barrier function, canonical metabolite transporters are missing in this membrane. Instead we identified several expanded groups of short chromatophore-targeted orphan proteins. Members of one of these groups are characterized by a single transmembrane helix, and others contain amphipathic helices. We hypothesize that these proteins are involved in modulating membrane permeability. Thus, the mechanism generating metabolic connectivity of the chromatophore fundamentally differs from the one for mitochondria and plastids, but likely rather resembles the poorly understood mechanism in various bacterial endosymbionts in plants and insects. Furthermore, our mass spectrometric analysis revealed an expanded family of chromatophore-targeted helical repeat proteins. These proteins show similar domain architectures as known organelle-targeted expression regulators of the octotrico peptide repeat type in algae and plants. Apparently these chromatophore-targeted proteins evolved convergently to plastid-targeted expression regulators and are likely involved in gene expression control in the chromatophore.
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Affiliation(s)
- Linda Oberleitner
- Department of Biology, Institute of Microbial Cell Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Gereon Poschmann
- Medical Faculty, Institute for Molecular Medicine, Proteome Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Luis Macorano
- Department of Biology, Institute of Microbial Cell Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Stephan Schott-Verdugo
- Department of Pharmacy, Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Faculty of Engineering, Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca, Chile
| | - Holger Gohlke
- Department of Pharmacy, Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Jülich Supercomputing Centre, John von Neumann Institute for Computing, Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Kai Stühler
- Medical Faculty, Institute for Molecular Medicine, Proteome Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Molecular Proteomics Laboratory, Biologisch-Medizinisches Forschungszentrum, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Eva C. M. Nowack
- Department of Biology, Institute of Microbial Cell Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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19
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Abstract
Production and expression of RNA requires the action of multiple RNA-binding proteins (RBPs). New RBPs are most often created by novel combinations of dedicated RNA-binding modules. However, recruiting existing genes to create new RBPs is also an important evolutionary strategy. In this report, we analyzed the eight-member uL18 ribosomal protein family in Arabidopsis uL18 proteins share a short structurally conserved domain that binds the 5S ribosomal RNA (rRNA) and allows its incorporation into ribosomes. Our results indicate that Arabidopsis uL18-Like proteins are targeted to either mitochondria or chloroplasts. While two members of the family are found in organelle ribosomes, we show here that two uL18-type proteins function as factors necessary for the splicing of certain mitochondrial and plastid group II introns. These two proteins do not cosediment with mitochondrial or plastid ribosomes but instead associate with the introns whose splicing they promote. Our study thus reveals that the RNA-binding capacity of uL18 ribosomal proteins has been repurposed to create factors that facilitate the splicing of organellar introns.
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20
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Marondedze C. The increasing diversity and complexity of the RNA-binding protein repertoire in plants. Proc Biol Sci 2020; 287:20201397. [PMID: 32962543 PMCID: PMC7542812 DOI: 10.1098/rspb.2020.1397] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/01/2020] [Indexed: 02/07/2023] Open
Abstract
Post-transcriptional regulation has far-reaching implications on the fate of RNAs. It is gaining increasing momentum as a critical component in adjusting global cellular transcript levels during development and in response to environmental stresses. In this process, RNA-binding proteins (RBPs) are indispensable chaperones that naturally bind RNA via one or multiple globular RNA-binding domains (RBDs) changing the function or fate of the bound RNAs. Despite the technical challenges faced in plants in large-scale studies, several hundreds of these RBPs have been discovered and elucidated globally over the past few years. Recent discoveries have more than doubled the number of proteins implicated in RNA interaction, including identification of RBPs lacking classical RBDs. This review will discuss these new emerging classes of RBPs, focusing on the current state of the RBP repertoire in Arabidopsis thaliana, including the diverse functional roles derived from quantitative studies implicating RBPs in abiotic stress responses. Notably, this review highlights that 836 RBPs are enriched as Arabidopsis RBPs while 1865 can be classified as candidate RBPs. The review will also outline outstanding areas within this field that require addressing to advance our understanding and potential biotechnological applications of RBPs.
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Affiliation(s)
- C. Marondedze
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
- Biological and Environmental Sciences and Engineering Division, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
- Department of Biochemistry, Midlands State University, P. Bag 9055, Gweru, Zimbabwe
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21
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Méteignier L, Ghandour R, Meierhoff K, Zimmerman A, Chicher J, Baumberger N, Alioua A, Meurer J, Zoschke R, Hammani K. The Arabidopsis mTERF-repeat MDA1 protein plays a dual function in transcription and stabilization of specific chloroplast transcripts within the psbE and ndhH operons. THE NEW PHYTOLOGIST 2020; 227:1376-1391. [PMID: 32343843 PMCID: PMC7496394 DOI: 10.1111/nph.16625] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 04/15/2020] [Indexed: 05/28/2023]
Abstract
The mTERF gene family encodes for nucleic acid binding proteins that are predicted to regulate organellar gene expression in eukaryotes. Despite the implication of this gene family in plant development and response to abiotic stresses, a precise molecular function was assigned to only a handful number of its c. 30 members in plants. Using a reverse genetics approach in Arabidopsis thaliana and combining molecular and biochemical techniques, we revealed new functions for the chloroplast mTERF protein, MDA1. We demonstrated that MDA1 associates in vivo with components of the plastid-encoded RNA polymerase and transcriptional active chromosome complexes. MDA1 protein binds in vivo and in vitro with specificity to 27-bp DNA sequences near the 5'-end of psbE and ndhA chloroplast genes to stimulate their transcription, and additionally promotes the stabilization of the 5'-ends of processed psbE and ndhA messenger (m)RNAs. Finally, we provided evidence that MDA1 function in gene transcription likely coordinates RNA folding and the action of chloroplast RNA-binding proteins on mRNA stabilization. Our results provide examples for the unexpected implication of DNA binding proteins and gene transcription in the regulation of mRNA stability in chloroplasts, blurring the boundaries between DNA and RNA metabolism in this organelle.
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Affiliation(s)
- Louis‐Valentin Méteignier
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Rabea Ghandour
- Max Planck Institute of Molecular Plant PhysiologyAm Mühlenberg 114476Potsdam‐GolmGermany
| | - Karin Meierhoff
- Institute of Developmental and Molecular Biology of PlantsHeinrich Heine University Düsseldorf40225DüsseldorfGermany
| | - Aude Zimmerman
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Johana Chicher
- Plateforme protéomique Strasbourg Esplanade FRC1589 du CNRSUniversité de Strasbourg15 rue René Descartes67084StrasbourgFrance
| | - Nicolas Baumberger
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Abdelmalek Alioua
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Jörg Meurer
- Plant SciencesFaculty of BiologyLudwig‐Maximilians‐University MunichGroßhaderner Street 2‐482152Planegg‐MartinsriedGermany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant PhysiologyAm Mühlenberg 114476Potsdam‐GolmGermany
| | - Kamel Hammani
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
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22
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Castandet B, Germain A, Hotto AM, Stern DB. Systematic sequencing of chloroplast transcript termini from Arabidopsis thaliana reveals >200 transcription initiation sites and the extensive imprints of RNA-binding proteins and secondary structures. Nucleic Acids Res 2020; 47:11889-11905. [PMID: 31732725 PMCID: PMC7145512 DOI: 10.1093/nar/gkz1059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 10/02/2019] [Accepted: 11/05/2019] [Indexed: 12/23/2022] Open
Abstract
Chloroplast transcription requires numerous quality control steps to generate the complex but selective mixture of accumulating RNAs. To gain insight into how this RNA diversity is achieved and regulated, we systematically mapped transcript ends by developing a protocol called Terminome-seq. Using Arabidopsis thaliana as a model, we catalogued >215 primary 5′ ends corresponding to transcription start sites (TSS), as well as 1628 processed 5′ ends and 1299 3′ ends. While most termini were found in intergenic regions, numerous abundant termini were also found within coding regions and introns, including several major TSS at unexpected locations. A consistent feature was the clustering of both 5′ and 3′ ends, contrasting with the prevailing description of discrete 5′ termini, suggesting an imprecision of the transcription and/or RNA processing machinery. Numerous termini correlated with the extremities of small RNA footprints or predicted stem-loop structures, in agreement with the model of passive RNA protection. Terminome-seq was also implemented for pnp1–1, a mutant lacking the processing enzyme polynucleotide phosphorylase. Nearly 2000 termini were altered in pnp1–1, revealing a dominant role in shaping the transcriptome. In summary, Terminome-seq permits precise delineation of the roles and regulation of the many factors involved in organellar transcriptome quality control.
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Affiliation(s)
- Benoît Castandet
- Boyce Thompson Institute, Ithaca, NY 14853, USA.,Institut des Sciences des Plantes de Paris Saclay (IPS2), UEVE, INRA, CNRS, Univ. Paris Sud, Université Paris-Saclay, F-91192 Gif sur Yvette, France.,Université de Paris, IPS2, F-91192 Gif sur Yvette, France
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23
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Waltz F, Corre N, Hashem Y, Giegé P. Specificities of the plant mitochondrial translation apparatus. Mitochondrion 2020; 53:30-37. [PMID: 32334144 DOI: 10.1016/j.mito.2020.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/14/2020] [Accepted: 04/21/2020] [Indexed: 12/16/2022]
Abstract
Mitochondria are endosymbiotic organelles responsible for energy production in most eukaryotic cells. They host a genome and a fully functional gene expression machinery. In plants this machinery involves hundreds of pentatricopeptide repeat (PPR) proteins. Translation, the final step of mitochondrial gene expression is performed by mitochondrial ribosomes (mitoribosomes). The nature of these molecular machines remained elusive for a very long time. Because of their bacterial origin, it was expected that mitoribosomes would closely resemble bacterial ribosomes. However, recent advances in cryo-electron microscopy have revealed the extraordinary diversity of mitoribosome structure and composition. The plant mitoribosome was characterized for Arabidopsis. In plants, in contrast to other species such as mammals and kinetoplastids where rRNA has been largely reduced, the mitoribosome could be described as a protein/RNA-augmented bacterial ribosome. It has an oversized small subunit formed by expanded ribosomal RNAs and additional protein components when compared to bacterial ribosomes. The same holds true for the large subunit. The small subunit is characterized by a new elongated domain on the head. Among its additional proteins, several PPR proteins are core mitoribosome proteins. They mainly act at the structural level to stabilize and maintain the plant-specific ribosomal RNA expansions but could also be involved in translation initiation. Recent advances in plant mitoribosome composition and structure, its specialization for membrane protein synthesis, translation initiation, the regulation and dynamics of mitochondrial translation are reviewed here and put in perspective with the diversity of mitochondrial translation processes in the green lineage and in the wider context of eukaryote evolution.
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Affiliation(s)
- Florent Waltz
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, F 33600 Pessac, France
| | - Nicolas Corre
- Institut de biologie de moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, F 67084 Strasbourg, France
| | - Yaser Hashem
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, F 33600 Pessac, France
| | - Philippe Giegé
- Institut de biologie de moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, F 67084 Strasbourg, France.
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24
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Waltz F, Soufari H, Bochler A, Giegé P, Hashem Y. Cryo-EM structure of the RNA-rich plant mitochondrial ribosome. NATURE PLANTS 2020; 6:377-383. [PMID: 32251374 DOI: 10.1038/s41477-020-0631-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 03/02/2020] [Indexed: 05/25/2023]
Abstract
The vast majority of eukaryotic cells contain mitochondria, essential powerhouses and metabolic hubs1. These organelles have a bacterial origin and were acquired during an early endosymbiosis event2. Mitochondria possess specialized gene expression systems composed of various molecular machines, including the mitochondrial ribosomes (mitoribosomes). Mitoribosomes are in charge of translating the few essential mRNAs still encoded by mitochondrial genomes3. While chloroplast ribosomes strongly resemble those of bacteria4,5, mitoribosomes have diverged significantly during evolution and present strikingly different structures across eukaryotic species6-10. In contrast to animals and trypanosomatids, plant mitoribosomes have unusually expanded ribosomal RNAs and have conserved the short 5S rRNA, which is usually missing in mitoribosomes11. We have previously characterized the composition of the plant mitoribosome6, revealing a dozen plant-specific proteins in addition to the common conserved mitoribosomal proteins. In spite of the tremendous recent advances in the field, plant mitoribosomes remained elusive to high-resolution structural investigations and the plant-specific ribosomal features of unknown structures. Here, we present a cryo-electron microscopy study of the plant 78S mitoribosome from cauliflower at near-atomic resolution. We show that most of the plant-specific ribosomal proteins are pentatricopeptide repeat proteins (PPRs) that deeply interact with the plant-specific rRNA expansion segments. These additional rRNA segments and proteins reshape the overall structure of the plant mitochondrial ribosome, and we discuss their involvement in the membrane association and mRNA recruitment prior to translation initiation. Finally, our structure unveils an rRNA-constructive phase of mitoribosome evolution across eukaryotes.
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Affiliation(s)
- Florent Waltz
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, Pessac, France
| | - Heddy Soufari
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, Pessac, France
| | - Anthony Bochler
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, Pessac, France
| | - Philippe Giegé
- Institut de biologie de moléculaire des plantes, UPR 2357 du CNRS, Université de Strasbourg, Strasbourg, France.
| | - Yaser Hashem
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, Pessac, France.
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25
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Gawroński P, Pałac A, Scharff LB. Secondary Structure of Chloroplast mRNAs In Vivo and In Vitro. PLANTS (BASEL, SWITZERLAND) 2020; 9:E323. [PMID: 32143324 PMCID: PMC7154907 DOI: 10.3390/plants9030323] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/25/2020] [Accepted: 02/28/2020] [Indexed: 01/09/2023]
Abstract
mRNA secondary structure can influence gene expression, e.g., by influencing translation initiation. The probing of in vivo mRNA secondary structures is therefore necessary to understand what determines the efficiency and regulation of gene expression. Here, in vivo mRNA secondary structure was analyzed using dimethyl sulfate (DMS)-MaPseq and compared to in vitro-folded RNA. We used an approach to analyze specific, full-length transcripts. To test this approach, we chose low, medium, and high abundant mRNAs. We included both monocistronic and multicistronic transcripts. Because of the slightly alkaline pH of the chloroplast stroma, we could probe all four nucleotides with DMS. The structural information gained was evaluated using the known structure of the plastid 16S rRNA. This demonstrated that the results obtained for adenosines and cytidines were more reliable than for guanosines and uridines. The majority of mRNAs analyzed were less structured in vivo than in vitro. The in vivo secondary structure of the translation initiation region of most tested genes appears to be optimized for high translation efficiency.
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Affiliation(s)
- Piotr Gawroński
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
| | - Aleksandra Pałac
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
| | - Lars B. Scharff
- Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, 1871 Frederiksberg C, Denmark
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26
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Waltz F, Giegé P. Striking Diversity of Mitochondria-Specific Translation Processes across Eukaryotes. Trends Biochem Sci 2019; 45:149-162. [PMID: 31780199 DOI: 10.1016/j.tibs.2019.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/03/2019] [Accepted: 10/08/2019] [Indexed: 12/13/2022]
Abstract
Mitochondria are essential organelles that act as energy conversion powerhouses and metabolic hubs. Their gene expression machineries combine traits inherited from prokaryote ancestors and specific features acquired during eukaryote evolution. Mitochondrial research has wide implications ranging from human health to agronomy. We highlight recent advances in mitochondrial translation. Functional, biochemical, and structural data have revealed an unexpected diversity of mitochondrial translation systems, particularly of their key players, the mitochondrial ribosomes (mitoribosomes). Ribosome assembly and translation mechanisms, such as initiation, are discussed and put in perspective with the prevalence of eukaryote-specific families of mitochondrial translation factors such as pentatricopeptide repeat (PPR) proteins.
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Affiliation(s)
- Florent Waltz
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France; Institut Européen de Chimie et de Biologie, l'Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Bordeaux, 2 rue Robert Escarpit, 33607 Pessac, France.
| | - Philippe Giegé
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
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27
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Su HG, Li B, Song XY, Ma J, Chen J, Zhou YB, Chen M, Min DH, Xu ZS, Ma YZ. Genome-Wide Analysis of the DYW Subgroup PPR Gene Family and Identification of GmPPR4 Responses to Drought Stress. Int J Mol Sci 2019; 20:E5667. [PMID: 31726763 PMCID: PMC6888332 DOI: 10.3390/ijms20225667] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/25/2019] [Accepted: 11/06/2019] [Indexed: 12/11/2022] Open
Abstract
Pentatricopeptide-repeat (PPR) proteins were identified as a type of nucleus coding protein that is composed of multiple tandem repeats. It has been reported that PPR genes play an important role in RNA editing, plant growth and development, and abiotic stresses in plants. However, the functions of PPR proteins remain largely unknown in soybean. In this study, 179 DYW subgroup PPR genes were identified in soybean genome (Glycine max Wm82.a2.v1). Chromosomal location analysis indicated that DYW subgroup PPR genes were mapped to all 20 chromosomes. Phylogenetic relationship analysis revealed that DYW subgroup PPR genes were categorized into three distinct Clusters (I to III). Gene structure analysis showed that most PPR genes were featured by a lack of intron. Gene duplication analysis demonstrated 30 PPR genes (15 pairs; ~35.7%) were segmentally duplicated among Cluster I PPR genes. Furthermore, we validated the mRNA expression of three genes that were highly up-regulated in soybean drought- and salt-induced transcriptome database and found that the expression levels of GmPPR4 were induced under salt and drought stresses. Under drought stress condition, GmPPR4-overexpressing (GmPPR4-OE) plants showed delayed leaf rolling; higher content of proline (Pro); and lower contents of H2O2, O2- and malondialdehyde (MDA) compared with the empty vector (EV)-control plants. GmPPR4-OE plants exhibited increased transcripts of several drought-inducible genes compared with EV-control plants. Our results provided a comprehensive analysis of the DYW subgroup PPR genes and an insight for improving the drought tolerance in soybean.
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Affiliation(s)
- Hong-Gang Su
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China; (H.-G.S.); (B.L.); (J.C.); (Y.-B.Z.); (M.C.)
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China;
| | - Bo Li
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China; (H.-G.S.); (B.L.); (J.C.); (Y.-B.Z.); (M.C.)
| | - Xin-Yuan Song
- Agro-Biotechnology Research Institute, Jilin Academy of Agriculture Sciences, Changchun 130033, China;
| | - Jian Ma
- College of Agronomy, Jilin Agricultural University, Changchun 130118, China;
| | - Jun Chen
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China; (H.-G.S.); (B.L.); (J.C.); (Y.-B.Z.); (M.C.)
| | - Yong-Bin Zhou
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China; (H.-G.S.); (B.L.); (J.C.); (Y.-B.Z.); (M.C.)
| | - Ming Chen
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China; (H.-G.S.); (B.L.); (J.C.); (Y.-B.Z.); (M.C.)
| | - Dong-Hong Min
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China;
| | - Zhao-Shi Xu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China; (H.-G.S.); (B.L.); (J.C.); (Y.-B.Z.); (M.C.)
| | - You-Zhi Ma
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China; (H.-G.S.); (B.L.); (J.C.); (Y.-B.Z.); (M.C.)
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28
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Bouchoucha A, Waltz F, Bonnard G, Arrivé M, Hammann P, Kuhn L, Schelcher C, Zuber H, Gobert A, Giegé P. Determination of protein-only RNase P interactome in Arabidopsis mitochondria and chloroplasts identifies a complex between PRORP1 and another NYN domain nuclease. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:549-561. [PMID: 31319441 DOI: 10.1111/tpj.14458] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 07/03/2019] [Accepted: 07/09/2019] [Indexed: 06/10/2023]
Abstract
The essential type of endonuclease that removes 5' leader sequences from transfer RNA precursors is called RNase P. While ribonucleoprotein RNase P enzymes containing a ribozyme are found in all domains of life, another type of RNase P called 'PRORP', for 'PROtein-only RNase P', is composed of protein that occurs only in a wide variety of eukaryotes, in organelles and in the nucleus. Here, to find how PRORP functions integrate with other cell processes, we explored the protein interaction network of PRORP1 in Arabidopsis mitochondria and chloroplasts. Although PRORP proteins function as single subunit enzymes in vitro, we found that PRORP1 occurs in protein complexes and is present in high-molecular-weight fractions that contain mitochondrial ribosomes. The analysis of immunoprecipitated protein complexes identified proteins involved in organellar gene expression processes. In particular, direct interaction was established between PRORP1 and MNU2 a mitochondrial nuclease. A specific domain of MNU2 and a conserved signature of PRORP1 were found to be directly accountable for this protein interaction. Altogether, results revealed the existence of an RNA maturation complex in Arabidopsis mitochondria and suggested that PRORP proteins cooperated with other gene expression factors for RNA maturation in vivo.
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Affiliation(s)
- Ayoub Bouchoucha
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Florent Waltz
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Géraldine Bonnard
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Mathilde Arrivé
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Philippe Hammann
- Plateforme protéomique Strasbourg-Esplanade, CNRS, Université de Strasbourg, 15 rue René Descartes, Strasbourg, F-67084, France
| | - Lauriane Kuhn
- Plateforme protéomique Strasbourg-Esplanade, CNRS, Université de Strasbourg, 15 rue René Descartes, Strasbourg, F-67084, France
| | - Cédric Schelcher
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Hélène Zuber
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Anthony Gobert
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Philippe Giegé
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
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29
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Daras G, Rigas S, Alatzas A, Samiotaki M, Chatzopoulos D, Tsitsekian D, Papadaki V, Templalexis D, Banilas G, Athanasiadou AM, Kostourou V, Panayotou G, Hatzopoulos P. LEFKOTHEA Regulates Nuclear and Chloroplast mRNA Splicing in Plants. Dev Cell 2019; 50:767-779.e7. [PMID: 31447263 DOI: 10.1016/j.devcel.2019.07.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 04/27/2019] [Accepted: 07/25/2019] [Indexed: 12/14/2022]
Abstract
Eukaryotic organisms accomplish the removal of introns to produce mature mRNAs through splicing. Nuclear and organelle splicing mechanisms are distinctively executed by spliceosome and group II intron complex, respectively. Here, we show that LEFKOTHEA, a nuclear encoded RNA-binding protein, participates in chloroplast group II intron and nuclear pre-mRNA splicing. Transiently optimized LEFKOTHEA nuclear activity is fundamental for plant growth, whereas the loss of function abruptly arrests embryogenesis. Nucleocytoplasmic partitioning and chloroplast allocation are efficiently balanced via functional motifs in LEFKOTHEA polypeptide. In the context of nuclear-chloroplast coevolution, our results provide a strong paradigm of the convergence of RNA maturation mechanisms in the nucleus and chloroplasts to coordinately regulate gene expression and effectively control plant growth.
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Affiliation(s)
- Gerasimos Daras
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Stamatis Rigas
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Anastasios Alatzas
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Martina Samiotaki
- Institute for Bioinnovation, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
| | | | - Dikran Tsitsekian
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Vassiliki Papadaki
- Institute for Bioinnovation, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
| | | | - Georgios Banilas
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | | | - Vassiliki Kostourou
- Institute for Bioinnovation, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
| | - George Panayotou
- Institute for Bioinnovation, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
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30
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Rovira AG, Smith AG. PPR proteins - orchestrators of organelle RNA metabolism. PHYSIOLOGIA PLANTARUM 2019; 166:451-459. [PMID: 30809817 DOI: 10.1111/ppl.12950] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 02/21/2019] [Accepted: 02/21/2019] [Indexed: 05/21/2023]
Abstract
Pentatricopeptide repeat (PPR) proteins are important RNA regulators in chloroplasts and mitochondria, aiding in RNA editing, maturation, stabilisation or intron splicing, and in transcription and translation of organellar genes. In this review, we summarise all PPR proteins documented so far in plants and the green alga Chlamydomonas. By further analysis of the known target RNAs from Arabidopsis thaliana PPR proteins, we find that all organellar-encoded complexes are regulated by these proteins, although to differing extents. In particular, the orthologous complexes of NADH dehydrogenase (Complex I) in the mitochondria and NADH dehydrogenase-like (NDH) complex in the chloroplast were the most regulated, with respectively 60 and 28% of all characterised A. thaliana PPR proteins targeting their genes.
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Affiliation(s)
- Aleix Gorchs Rovira
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Alison G Smith
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
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31
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Zhang Y, Cui YL, Zhang XL, Yu QB, Wang X, Yuan XB, Qin XM, He XF, Huang C, Yang ZN. A nuclear-encoded protein, mTERF6, mediates transcription termination of rpoA polycistron for plastid-encoded RNA polymerase-dependent chloroplast gene expression and chloroplast development. Sci Rep 2018; 8:11929. [PMID: 30093718 PMCID: PMC6085346 DOI: 10.1038/s41598-018-30166-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 04/20/2018] [Indexed: 12/13/2022] Open
Abstract
The expression of plastid genes is regulated by two types of DNA-dependent RNA polymerases, plastid-encoded RNA polymerase (PEP) and nuclear-encoded RNA polymerase (NEP). The plastid rpoA polycistron encodes a series of essential chloroplast ribosome subunits and a core subunit of PEP. Despite the functional importance, little is known about the regulation of rpoA polycistron. In this work, we show that mTERF6 directly associates with a 3′-end sequence of rpoA polycistron in vitro and in vivo, and that absence of mTERF6 promotes read-through transcription at this site, indicating that mTERF6 acts as a factor required for termination of plastid genes’ transcription in vivo. In addition, the transcriptions of some essential ribosome subunits encoded by rpoA polycistron and PEP-dependent plastid genes are reduced in the mterf6 knockout mutant. RpoA, a PEP core subunit, accumulates to about 50% that of the wild type in the mutant, where early chloroplast development is impaired. Overall, our functional analyses of mTERF6 provide evidence that it is more likely a factor required for transcription termination of rpoA polycistron, which is essential for chloroplast gene expression and chloroplast development.
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Affiliation(s)
- Yi Zhang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.,Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Yong-Lan Cui
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xiao-Lei Zhang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Qing-Bo Yu
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xi Wang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xin-Bo Yuan
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xue-Mei Qin
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xiao-Fang He
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Chao Huang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Zhong-Nan Yang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
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32
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Trösch R, Barahimipour R, Gao Y, Badillo-Corona JA, Gotsmann VL, Zimmer D, Mühlhaus T, Zoschke R, Willmund F. Commonalities and differences of chloroplast translation in a green alga and land plants. NATURE PLANTS 2018; 4:564-575. [PMID: 30061751 DOI: 10.1038/s41477-018-0211-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 07/02/2018] [Indexed: 06/08/2023]
Abstract
Chloroplast gene expression is a fascinating and highly regulated process, which was mainly studied on specific genes in a few model organisms including the unicellular green alga Chlamydomonas (Chlamydomonas reinhardtii) and the embryophyte (land) plants tobacco (Nicotiana tabacum) and Arabidopsis (Arabidopsis thaliana). However, a direct plastid genome-wide interspecies comparison of chloroplast gene expression that includes translation was missing. We adapted a targeted chloroplast ribosome profiling approach to quantitatively compare RNA abundance and translation output between Chlamydomonas, tobacco and Arabidopsis. The re-analysis of established chloroplast mutants confirmed the capability of the approach by detecting known as well as previously undetected translation defects (including the potential photosystem II assembly-dependent regulation of PsbH). Systematic comparison of the algal and land plant wild-type gene expression showed that, for most genes, the steady-state translation output is highly conserved among the three species, while the levels of transcript accumulation are more distinct. Whereas in Chlamydomonas transcript accumulation and translation output are closely balanced, this correlation is less obvious in embryophytes, indicating more pronounced translational regulation. Altogether, this suggests that green algae and land plants evolved different strategies to achieve conserved levels of protein synthesis.
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Affiliation(s)
- Raphael Trösch
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Kaiserslautern, Germany
| | | | - Yang Gao
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | | | - Vincent Leon Gotsmann
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Kaiserslautern, Germany
| | - David Zimmer
- Computational Systems Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Timo Mühlhaus
- Computational Systems Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.
| | - Felix Willmund
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Kaiserslautern, Germany.
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33
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Field B. Green magic: regulation of the chloroplast stress response by (p)ppGpp in plants and algae. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:2797-2807. [PMID: 29281108 DOI: 10.1093/jxb/erx485] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/14/2017] [Indexed: 06/07/2023]
Abstract
The hyperphosphorylated nucleotides guanosine pentaphosphate and tetraphosphate [together referred to as (p)ppGpp, or 'magic spot'] orchestrate a signalling cascade in bacteria that controls growth under optimal conditions and in response to environmental stress. (p)ppGpp is also found in the chloroplasts of plants and algae where it has also been shown to accumulate in response to abiotic stress. Recent studies suggest that (p)ppGpp is a potent inhibitor of chloroplast gene expression in vivo, and is a significant regulator of chloroplast function that can influence both the growth and the development of plants. However, little is currently known about how (p)ppGpp is wired into eukaryotic signalling pathways, or how it may act to enhance fitness when plants or algae are exposed to environmental stress. This review discusses our current understanding of (p)ppGpp metabolism and its extent in plants and algae, and how (p)ppGpp signalling may be an important factor that is capable of influencing growth and stress acclimation in this major group of organisms.
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Affiliation(s)
- Ben Field
- Aix Marseille Univ, CEA, CNRS, France
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34
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Jourdain AA, Popow J, de la Fuente MA, Martinou JC, Anderson P, Simarro M. The FASTK family of proteins: emerging regulators of mitochondrial RNA biology. Nucleic Acids Res 2017; 45:10941-10947. [PMID: 29036396 PMCID: PMC5737537 DOI: 10.1093/nar/gkx772] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 09/14/2017] [Indexed: 12/22/2022] Open
Abstract
The FASTK family proteins have recently emerged as key post-transcriptional regulators of mitochondrial gene expression. FASTK, the founding member and its homologs FASTKD1-5 are architecturally related RNA-binding proteins, each having a different function in the regulation of mitochondrial RNA biology, from mRNA processing and maturation to ribosome assembly and translation. In this review, we outline the structure, evolution and function of these FASTK proteins and discuss the individual role that each has in mitochondrial RNA biology. In addition, we highlight the aspects of FASTK research that still require more attention.
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Affiliation(s)
- Alexis A Jourdain
- Department of Cell Biology, University of Geneva, 1211 Geneva 4, Switzerland
| | - Johannes Popow
- Department of Cancer Cell Signalling, Boehringer-Ingelheim Regional Center Vienna, 1121 Vienna, Austria
| | - Miguel A de la Fuente
- Departamento de Biología, Histología y Farmacología, Universidad de Valladolid, Instituto de Biología y Genética Molecular, Valladolid 47003, Spain
| | | | - Paul Anderson
- Division of Rheumatology, Immunology and Allergy, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Maria Simarro
- Departamento de Enfermería, Universidad de Valladolid, Instituto de Biología y Genética Molecular, Valladolid 47003, Spain
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35
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Cavaiuolo M, Kuras R, Wollman F, Choquet Y, Vallon O. Small RNA profiling in Chlamydomonas: insights into chloroplast RNA metabolism. Nucleic Acids Res 2017; 45:10783-10799. [PMID: 28985404 PMCID: PMC5737564 DOI: 10.1093/nar/gkx668] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 07/18/2017] [Accepted: 07/28/2017] [Indexed: 12/20/2022] Open
Abstract
In Chlamydomonas reinhardtii, regulation of chloroplast gene expression is mainly post-transcriptional. It requires nucleus-encoded trans-acting protein factors for maturation/stabilization (M factors) or translation (T factors) of specific target mRNAs. We used long- and small-RNA sequencing to generate a detailed map of the transcriptome. Clusters of sRNAs marked the 5' end of all mature mRNAs. Their absence in M-factor mutants reflects the protection of transcript 5' end by the cognate factor. Enzymatic removal of 5'-triphosphates allowed identifying those cosRNA that mark a transcription start site. We detected another class of sRNAs derived from low abundance transcripts, antisense to mRNAs. The formation of antisense sRNAs required the presence of the complementary mRNA and was stimulated when translation was inhibited by chloramphenicol or lincomycin. We propose that they derive from degradation of double-stranded RNAs generated by pairing of antisense and sense transcripts, a process normally hindered by the traveling of the ribosomes. In addition, chloramphenicol treatment, by freezing ribosomes on the mRNA, caused the accumulation of 32-34 nt ribosome-protected fragments. Using this 'in vivo ribosome footprinting', we identified the function and molecular target of two candidate trans-acting factors.
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Affiliation(s)
- Marina Cavaiuolo
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Richard Kuras
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Francis‐André Wollman
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Yves Choquet
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Olivier Vallon
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
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36
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Pinker F, Schelcher C, Fernandez-Millan P, Gobert A, Birck C, Thureau A, Roblin P, Giegé P, Sauter C. Biophysical analysis of Arabidopsis protein-only RNase P alone and in complex with tRNA provides a refined model of tRNA binding. J Biol Chem 2017; 292:13904-13913. [PMID: 28696260 PMCID: PMC5572917 DOI: 10.1074/jbc.m117.782078] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 07/06/2017] [Indexed: 11/06/2022] Open
Abstract
RNase P is a universal enzyme that removes 5' leader sequences from tRNA precursors. The enzyme is therefore essential for maturation of functional tRNAs and mRNA translation. RNase P represents a unique example of an enzyme that can occur either as ribonucleoprotein or as protein alone. The latter form of the enzyme, called protein-only RNase P (PRORP), is widespread in eukaryotes in which it can provide organellar or nuclear RNase P activities. Here, we have focused on Arabidopsis nuclear PRORP2 and its interaction with tRNA substrates. Affinity measurements helped assess the respective importance of individual pentatricopeptide repeat motifs in PRORP2 for RNA binding. We characterized the PRORP2 structure by X-ray crystallography and by small-angle X-ray scattering in solution as well as that of its complex with a tRNA precursor by small-angle X-ray scattering. Of note, our study reports the first structural data of a PRORP-tRNA complex. Combined with complementary biochemical and biophysical analyses, our structural data suggest that PRORP2 undergoes conformational changes to accommodate its substrate. In particular, the catalytic domain and the RNA-binding domain can move around a central hinge. Altogether, this work provides a refined model of the PRORP-tRNA complex that illustrates how protein-only RNase P enzymes specifically bind tRNA and highlights the contribution of protein dynamics to achieve this specific interaction.
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Affiliation(s)
- Franziska Pinker
- From the Université de Strasbourg, CNRS, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France,; Université de Strasbourg, CNRS, Institut de Biologie Moléculaire des Plantes, UPR 2357, F-67084 Strasbourg, France
| | - Cédric Schelcher
- Université de Strasbourg, CNRS, Institut de Biologie Moléculaire des Plantes, UPR 2357, F-67084 Strasbourg, France
| | - Pablo Fernandez-Millan
- From the Université de Strasbourg, CNRS, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Anthony Gobert
- Université de Strasbourg, CNRS, Institut de Biologie Moléculaire des Plantes, UPR 2357, F-67084 Strasbourg, France
| | - Catherine Birck
- Université de Strasbourg, CNRS, Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104, F-67404 Illkirch, France
| | - Aurélien Thureau
- Synchrotron SOLEIL, l'Orme des Merisiers, F-91410 Saint Aubin, France
| | - Pierre Roblin
- Synchrotron SOLEIL, l'Orme des Merisiers, F-91410 Saint Aubin, France; Unité de Recherche Biopolymères, Interactions, Assemblages (URBIA-Nantes), Institut National de la Recherche Agronomique Centre de Nantes, 60 rue de la Géraudière, UR 1268, F-44316 Nantes, France
| | - Philippe Giegé
- Université de Strasbourg, CNRS, Institut de Biologie Moléculaire des Plantes, UPR 2357, F-67084 Strasbourg, France,.
| | - Claude Sauter
- From the Université de Strasbourg, CNRS, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France,.
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37
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Leister D, Wang L, Kleine T. Organellar Gene Expression and Acclimation of Plants to Environmental Stress. FRONTIERS IN PLANT SCIENCE 2017; 8:387. [PMID: 28377785 PMCID: PMC5359298 DOI: 10.3389/fpls.2017.00387] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/07/2017] [Indexed: 05/03/2023]
Abstract
Organelles produce ATP and a variety of vital metabolites, and are indispensable for plant development. While most of their original gene complements have been transferred to the nucleus in the course of evolution, they retain their own genomes and gene-expression machineries. Hence, organellar function requires tight coordination between organellar gene expression (OGE) and nuclear gene expression (NGE). OGE requires various nucleus-encoded proteins that regulate transcription, splicing, trimming, editing, and translation of organellar RNAs, which necessitates nucleus-to-organelle (anterograde) communication. Conversely, changes in OGE trigger retrograde signaling that modulates NGE in accordance with the current status of the organelle. Changes in OGE occur naturally in response to developmental and environmental changes, and can be artificially induced by inhibitors such as lincomycin or mutations that perturb OGE. Focusing on the model plant Arabidopsis thaliana and its plastids, we review here recent findings which suggest that perturbations of OGE homeostasis regularly result in the activation of acclimation and tolerance responses, presumably via retrograde signaling.
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38
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Xu D, Leister D, Kleine T. Arabidopsis thaliana mTERF10 and mTERF11, but Not mTERF12, Are Involved in the Response to Salt Stress. FRONTIERS IN PLANT SCIENCE 2017; 8:1213. [PMID: 28769941 PMCID: PMC5509804 DOI: 10.3389/fpls.2017.01213] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 06/27/2017] [Indexed: 05/10/2023]
Abstract
Plastid gene expression (PGE) is crucial for plant development and acclimation to various environmental stress conditions. Members of the "mitochondrial transcription termination factor" (mTERF) family, which are present in both metazoans and plants, are involved in organellar gene expression. Arabidopsis thaliana contains 35 mTERF proteins, of which mTERF10, mTERF11, and mTERF12 were previously assigned to the "chloroplast-associated" group. Here, we show that all three are localized to chloroplast nucleoids, which are associated with PGE. Knock-down of MTERF10, MTERF11, or MTERF12 has no overt phenotypic effect under normal growth conditions. However, in silico analysis of MTERF10, -11, and -12 expression levels points to a possible involvement of mTERF10 and mTERF11 in responses to abiotic stress. Exposing mutant lines for 7 days to moderate heat (30°C) or light stress (400 μmol photons m-2 s-1) fails to induce a phenotype in mterf mutant lines. However, growth on MS medium supplemented with NaCl reveals that overexpression of MTERF11 results in higher salt tolerance. Conversely, mterf10 mutants are hypersensitive to salt stress, while plants that modestly overexpress MTERF10 are markedly less susceptible. Furthermore, MTERF10 overexpression leads to enhanced germination and growth on MS medium supplemented with ABA. These findings point to an involvement of mTERF10 in salt tolerance, possibly through an ABA-mediated mechanism. Thus, characterization of an increasing number of plant mTERF proteins reveals their roles in the response, tolerance and acclimation to different abiotic stresses.
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39
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Bonnard G, Gobert A, Arrivé M, Pinker F, Salinas-Giegé T, Giegé P. Transfer RNA maturation in Chlamydomonas mitochondria, chloroplast and the nucleus by a single RNase P protein. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 87:270-280. [PMID: 27133210 DOI: 10.1111/tpj.13198] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/06/2016] [Accepted: 04/15/2016] [Indexed: 06/05/2023]
Abstract
The maturation of tRNA precursors involves the 5' cleavage of leader sequences by an essential endonuclease called RNase P. Beyond the ancestral ribonucleoprotein (RNP) RNase P, a second type of RNase P called PRORP (protein-only RNase P) evolved in eukaryotes. The current view on the distribution of RNase P in cells is that multiple RNPs, multiple PRORPs or a combination of both, perform specialised RNase P activities in the different compartments where gene expression occurs. Here, we identify a single gene encoding PRORP in the green alga Chlamydomonas reinhardtii while no RNP is found. We show that its product, CrPRORP, is triple-localised to mitochondria, the chloroplast and the nucleus. Its downregulation results in impaired tRNA biogenesis in both organelles and the nucleus. CrPRORP, as a single-subunit RNase P for an entire organism, makes up the most compact and versatile RNase P machinery described in either prokaryotes or eukaryotes.
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Affiliation(s)
- Géraldine Bonnard
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, 67000, Strasbourg, France
| | - Anthony Gobert
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, 67000, Strasbourg, France
| | - Mathilde Arrivé
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, 67000, Strasbourg, France
| | - Franziska Pinker
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, 67000, Strasbourg, France
| | - Thalia Salinas-Giegé
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, 67000, Strasbourg, France
| | - Philippe Giegé
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 Rue du Général Zimmer, 67000, Strasbourg, France.
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40
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Zoschke R, Watkins KP, Miranda RG, Barkan A. The PPR-SMR protein PPR53 enhances the stability and translation of specific chloroplast RNAs in maize. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:594-606. [PMID: 26643268 PMCID: PMC4777676 DOI: 10.1111/tpj.13093] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/19/2015] [Accepted: 11/24/2015] [Indexed: 05/09/2023]
Abstract
Pentatricopeptide repeat (PPR) proteins are helical repeat proteins that bind RNA and influence gene expression in mitochondria and chloroplasts. Several PPR proteins in plants harbor a carboxy-terminal small-MutS-related (SMR) domain, but the functions of the SMR appendage are unknown. To address this issue, we studied a maize PPR-SMR protein denoted PPR53 (GRMZM2G438524), which is orthologous to the Arabidopsis protein SOT1 (AT5G46580). Null ppr53 alleles condition a chlorotic, seedling-lethal phenotype and a reduction in plastid ribosome content. Plastome-wide transcriptome and translatome analyses revealed strong defects in the expression of the ndhA and rrn23 genes, which were superimposed on secondary effects resulting from a decrease in plastid ribosome content. Transcripts with processed 5'-ends mapping approximately 70 nucleotides upstream of rrn23 and ndhA are absent in ppr53 mutants, and the translational efficiency of the residual ndhA mRNAs is reduced. Recombinant PPR53 binds with high affinity and specificity to the 5' proximal region of the PPR53-dependent 23S rRNA, suggesting that PPR53 protects this RNA via a barrier mechanism similar to that described for several PPR proteins lacking SMR motifs. However, recombinant PPR53 did not bind with high affinity to the ndhA 5' untranslated region, suggesting that PPR53's RNA-stabilization and translation-enhancing effects at the ndhA locus involve the participation of other factors.
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Affiliation(s)
- Reimo Zoschke
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | | | - Rafael G. Miranda
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
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41
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Bohne AV, Schwenkert S, Grimm B, Nickelsen J. Roles of Tetratricopeptide Repeat Proteins in Biogenesis of the Photosynthetic Apparatus. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 324:187-227. [PMID: 27017009 DOI: 10.1016/bs.ircmb.2016.01.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Biosynthesis of the photosynthetic apparatus is a complex operation, which includes the concerted synthesis and assembly of lipids, pigments and metal cofactors, and dozens of proteins. Research conducted in recent years has shown that these processes, as well as the stabilization and repair of this molecular machinery, are facilitated by transiently acting regulatory proteins, many of which belong to the superfamily of helical repeat proteins. Here, we focus on one of its families in photoautotrophic model organisms, the tetratricopeptide repeat (TPR) proteins, which participate in almost all of these steps and are crucial for biogenesis of the thylakoid membrane.
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Affiliation(s)
- A-V Bohne
- Molecular Plant Sciences, Ludwig-Maximilians-University, Munich, Germany
| | - S Schwenkert
- Botany, Ludwig-Maximilians-University, Munich, Germany
| | - B Grimm
- Institute of Biology/Plant Physiology, Humboldt University, Berlin, Germany
| | - J Nickelsen
- Molecular Plant Sciences, Ludwig-Maximilians-University, Munich, Germany.
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42
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Cheng S, Gutmann B, Zhong X, Ye Y, Fisher MF, Bai F, Castleden I, Song Y, Song B, Huang J, Liu X, Xu X, Lim BL, Bond CS, Yiu SM, Small I. Redefining the structural motifs that determine RNA binding and RNA editing by pentatricopeptide repeat proteins in land plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:532-47. [PMID: 26764122 DOI: 10.1111/tpj.13121] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 01/05/2016] [Indexed: 05/02/2023]
Abstract
The pentatricopeptide repeat (PPR) proteins form one of the largest protein families in land plants. They are characterised by tandem 30-40 amino acid motifs that form an extended binding surface capable of sequence-specific recognition of RNA strands. Almost all of them are post-translationally targeted to plastids and mitochondria, where they play important roles in post-transcriptional processes including splicing, RNA editing and the initiation of translation. A code describing how PPR proteins recognise their RNA targets promises to accelerate research on these proteins, but making use of this code requires accurate definition and annotation of all of the various nucleotide-binding motifs in each protein. We have used a structural modelling approach to define 10 different variants of the PPR motif found in plant proteins, in addition to the putative deaminase motif that is found at the C-terminus of many RNA-editing factors. We show that the super-helical RNA-binding surface of RNA-editing factors is potentially longer than previously recognised. We used the redefined motifs to develop accurate and consistent annotations of PPR sequences from 109 genomes. We report a high error rate in PPR gene models in many public plant proteomes, due to gene fusions and insertions of spurious introns. These consistently annotated datasets across a wide range of species are valuable resources for future comparative genomics studies, and an essential pre-requisite for accurate large-scale computational predictions of PPR targets. We have created a web portal (http://www.plantppr.com) that provides open access to these resources for the community.
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Affiliation(s)
- Shifeng Cheng
- HKU-BGI Bioinformatics Algorithms and Core Technology Research Laboratory, Department of Computer Science, The University of Hong Kong, Hong Kong, China
- BGI-Shenzhen, Shenzhen, 518083, China
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Bernard Gutmann
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, 6009, Australia
| | | | - Yongtao Ye
- HKU-BGI Bioinformatics Algorithms and Core Technology Research Laboratory, Department of Computer Science, The University of Hong Kong, Hong Kong, China
| | - Mark F Fisher
- School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia, Australia
| | | | - Ian Castleden
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, 6009, Australia
| | - Yue Song
- BGI-Shenzhen, Shenzhen, 518083, China
| | - Bo Song
- BGI-Shenzhen, Shenzhen, 518083, China
| | | | - Xin Liu
- BGI-Shenzhen, Shenzhen, 518083, China
| | - Xun Xu
- BGI-Shenzhen, Shenzhen, 518083, China
| | - Boon L Lim
- HKU-BGI Bioinformatics Algorithms and Core Technology Research Laboratory, Department of Computer Science, The University of Hong Kong, Hong Kong, China
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Charles S Bond
- School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia, Australia
| | - Siu-Ming Yiu
- HKU-BGI Bioinformatics Algorithms and Core Technology Research Laboratory, Department of Computer Science, The University of Hong Kong, Hong Kong, China
| | - Ian Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, 6009, Australia
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Hauser K, Essuman B, He Y, Coutsias E, Garcia-Diaz M, Simmerling C. A human transcription factor in search mode. Nucleic Acids Res 2015; 44:63-74. [PMID: 26673724 PMCID: PMC4705650 DOI: 10.1093/nar/gkv1091] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 10/07/2015] [Indexed: 12/14/2022] Open
Abstract
Transcription factors (TF) can change shape to bind and recognize DNA, shifting the energy landscape from a weak binding, rapid search mode to a higher affinity recognition mode. However, the mechanism(s) driving this conformational change remains unresolved and in most cases high-resolution structures of the non-specific complexes are unavailable. Here, we investigate the conformational switch of the human mitochondrial transcription termination factor MTERF1, which has a modular, superhelical topology complementary to DNA. Our goal was to characterize the details of the non-specific search mode to complement the crystal structure of the specific binding complex, providing a basis for understanding the recognition mechanism. In the specific complex, MTERF1 binds a significantly distorted and unwound DNA structure, exhibiting a protein conformation incompatible with binding to B-form DNA. In contrast, our simulations of apo MTERF1 revealed significant flexibility, sampling structures with superhelical pitch and radius complementary to the major groove of B-DNA. Docking these structures to B-DNA followed by unrestrained MD simulations led to a stable complex in which MTERF1 was observed to undergo spontaneous diffusion on the DNA. Overall, the data support an MTERF1-DNA binding and recognition mechanism driven by intrinsic dynamics of the MTERF1 superhelical topology.
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Affiliation(s)
- Kevin Hauser
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, USA
| | | | - Yiqing He
- Great Neck South High School, Great Neck, NY 11023, USA
| | - Evangelos Coutsias
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Miguel Garcia-Diaz
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Carlos Simmerling
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, USA
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44
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Lefebvre-Legendre L, Choquet Y, Kuras R, Loubéry S, Douchi D, Goldschmidt-Clermont M. A nucleus-encoded chloroplast protein regulated by iron availability governs expression of the photosystem I subunit PsaA in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2015; 167:1527-40. [PMID: 25673777 PMCID: PMC4378161 DOI: 10.1104/pp.114.253906] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The biogenesis of the photosynthetic electron transfer chain in the thylakoid membranes requires the concerted expression of genes in the chloroplast and the nucleus. Chloroplast gene expression is subjected to anterograde control by a battery of nucleus-encoded proteins that are imported in the chloroplast, where they mostly intervene at posttranscriptional steps. Using a new genetic screen, we identify a nuclear mutant that is required for expression of the PsaA subunit of photosystem I (PSI) in the chloroplast of Chlamydomonas reinhardtii. This mutant is affected in the stability and translation of psaA messenger RNA. The corresponding gene, TRANSLATION OF psaA1 (TAA1), encodes a large protein with two domains that are thought to mediate RNA binding: an array of octatricopeptide repeats (OPR) and an RNA-binding domain abundant in apicomplexans (RAP) domain. We show that as expected for its function, TAA1 is localized in the chloroplast. It was previously shown that when mixotrophic cultures of C. reinhardtii (which use both photosynthesis and mitochondrial respiration for growth) are shifted to conditions of iron limitation, there is a strong decrease in the accumulation of PSI and that this is rapidly reversed when iron is resupplied. Under these conditions, TAA1 protein is also down-regulated through a posttranscriptional mechanism and rapidly reaccumulates when iron is restored. These observations reveal a concerted regulation of PSI and of TAA1 in response to iron availability.
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Affiliation(s)
- Linnka Lefebvre-Legendre
- Department of Botany and Plant Biology and Department of Molecular Biology, University of Geneva, 1211 Geneva 4, Switzerland (L.L.-L., S.L., D.D., M.G.-C.); andUnité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, 75005 Paris, France (Y.C., R.K.)
| | - Yves Choquet
- Department of Botany and Plant Biology and Department of Molecular Biology, University of Geneva, 1211 Geneva 4, Switzerland (L.L.-L., S.L., D.D., M.G.-C.); andUnité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, 75005 Paris, France (Y.C., R.K.)
| | - Richard Kuras
- Department of Botany and Plant Biology and Department of Molecular Biology, University of Geneva, 1211 Geneva 4, Switzerland (L.L.-L., S.L., D.D., M.G.-C.); andUnité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, 75005 Paris, France (Y.C., R.K.)
| | - Sylvain Loubéry
- Department of Botany and Plant Biology and Department of Molecular Biology, University of Geneva, 1211 Geneva 4, Switzerland (L.L.-L., S.L., D.D., M.G.-C.); andUnité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, 75005 Paris, France (Y.C., R.K.)
| | - Damien Douchi
- Department of Botany and Plant Biology and Department of Molecular Biology, University of Geneva, 1211 Geneva 4, Switzerland (L.L.-L., S.L., D.D., M.G.-C.); andUnité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, 75005 Paris, France (Y.C., R.K.)
| | - Michel Goldschmidt-Clermont
- Department of Botany and Plant Biology and Department of Molecular Biology, University of Geneva, 1211 Geneva 4, Switzerland (L.L.-L., S.L., D.D., M.G.-C.); andUnité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, 75005 Paris, France (Y.C., R.K.)
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45
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Jalal A, Schwarz C, Schmitz-Linneweber C, Vallon O, Nickelsen J, Bohne AV. A small multifunctional pentatricopeptide repeat protein in the chloroplast of Chlamydomonas reinhardtii. MOLECULAR PLANT 2015; 8:412-26. [PMID: 25702521 DOI: 10.1016/j.molp.2014.11.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 11/10/2014] [Accepted: 11/24/2014] [Indexed: 05/21/2023]
Abstract
Organellar biogenesis is mainly regulated by nucleus-encoded factors, which act on various steps of gene expression including RNA editing, processing, splicing, stabilization, and translation initiation. Among these regulatory factors, pentatricopeptide repeat (PPR) proteins form the largest family of RNA binding proteins, with hundreds of members in flowering plants. In striking contrast, the genome of the unicellular green alga Chlamydomonas reinhardtii encodes only 14 such proteins. In this study, we analyzed PPR7, the smallest and most highly expressed PPR protein in C. reinhardtii. Green fluorescent protein-based localization and gel-filtration analysis revealed that PPR7 forms a part of a high-molecular-weight ribonucleoprotein complex in the chloroplast stroma. RIP-chip analysis of PPR7-bound RNAs demonstrated that the protein associates with a diverse set of chloroplast transcripts in vivo, i.e. rrnS, psbH, rpoC2, rbcL, atpA, cemA-atpH, tscA, and atpI-psaJ. Furthermore, the investigation of PPR7 RNAi strains revealed that depletion of PPR7 results in a light-sensitive phenotype, accompanied by altered levels of its target RNAs that are compatible with the defects in their maturation or stabilization. PPR7 is thus an unusual type of small multifunctional PPR protein, which interacts, probably in conjunction with other RNA binding proteins, with numerous target RNAs to promote a variety of post-transcriptional events.
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Affiliation(s)
- Abdullah Jalal
- Molecular Plant Sciences, Ludwig-Maximillians-University, Grosshaderner Straße 2-4, 82152 Planegg-Martinsried, Germany
| | - Christian Schwarz
- Molecular Plant Sciences, Ludwig-Maximillians-University, Grosshaderner Straße 2-4, 82152 Planegg-Martinsried, Germany
| | | | - Olivier Vallon
- UMR7141 CNRS/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Jörg Nickelsen
- Molecular Plant Sciences, Ludwig-Maximillians-University, Grosshaderner Straße 2-4, 82152 Planegg-Martinsried, Germany
| | - Alexandra-Viola Bohne
- Molecular Plant Sciences, Ludwig-Maximillians-University, Grosshaderner Straße 2-4, 82152 Planegg-Martinsried, Germany.
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46
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Salinas-Giegé T, Giegé R, Giegé P. tRNA biology in mitochondria. Int J Mol Sci 2015; 16:4518-59. [PMID: 25734984 PMCID: PMC4394434 DOI: 10.3390/ijms16034518] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/23/2015] [Accepted: 01/29/2015] [Indexed: 01/23/2023] Open
Abstract
Mitochondria are the powerhouses of eukaryotic cells. They are considered as semi-autonomous because they have retained genomes inherited from their prokaryotic ancestor and host fully functional gene expression machineries. These organelles have attracted considerable attention because they combine bacterial-like traits with novel features that evolved in the host cell. Among them, mitochondria use many specific pathways to obtain complete and functional sets of tRNAs as required for translation. In some instances, tRNA genes have been partially or entirely transferred to the nucleus and mitochondria require precise import systems to attain their pool of tRNAs. Still, tRNA genes have also often been maintained in mitochondria. Their genetic arrangement is more diverse than previously envisaged. The expression and maturation of mitochondrial tRNAs often use specific enzymes that evolved during eukaryote history. For instance many mitochondria use a eukaryote-specific RNase P enzyme devoid of RNA. The structure itself of mitochondrial encoded tRNAs is also very diverse, as e.g., in Metazoan, where tRNAs often show non canonical or truncated structures. As a result, the translational machinery in mitochondria evolved adapted strategies to accommodate the peculiarities of these tRNAs, in particular simplified identity rules for their aminoacylation. Here, we review the specific features of tRNA biology in mitochondria from model species representing the major eukaryotic groups, with an emphasis on recent research on tRNA import, maturation and aminoacylation.
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Affiliation(s)
- Thalia Salinas-Giegé
- Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 rue du Général Zimmer, F-67084 Strasbourg Cedex, France.
| | - Richard Giegé
- Institut de Biologie Moléculaire et Cellulaire, CNRS and Université de Strasbourg, 15 rue René Descartes, F-67084 Strasbourg Cedex, France.
| | - Philippe Giegé
- Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 rue du Général Zimmer, F-67084 Strasbourg Cedex, France.
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47
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Chloroplast RNA polymerases: Role in chloroplast biogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:761-9. [PMID: 25680513 DOI: 10.1016/j.bbabio.2015.02.004] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 01/26/2015] [Accepted: 02/02/2015] [Indexed: 12/18/2022]
Abstract
Plastid genes are transcribed by two types of RNA polymerase in angiosperms: the bacterial type plastid-encoded RNA polymerase (PEP) and one (RPOTp in monocots) or two (RPOTp and RPOTmp in dicots) nuclear-encoded RNA polymerase(s) (NEP). PEP is a bacterial-type multisubunit enzyme composed of core subunits (coded for by the plastid rpoA, rpoB, rpoC1 and rpoC2 genes) and additional protein factors (sigma factors and polymerase associated protein, PAPs) encoded in the nuclear genome. Sigma factors are required by PEP for promoter recognition. Six different sigma factors are used by PEP in Arabidopsis plastids. NEP activity is represented by phage-type RNA polymerases. Only one NEP subunit has been identified, which bears the catalytic activity. NEP and PEP use different promoters. Many plastid genes have both PEP and NEP promoters. PEP dominates in the transcription of photosynthesis genes. Intriguingly, rpoB belongs to the few genes transcribed exclusively by NEP. Both NEP and PEP are active in non-green plastids and in chloroplasts at all stages of development. The transcriptional activity of NEP and PEP is affected by endogenous and exogenous factors. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
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48
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Emerging functions of mammalian and plant mTERFs. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:786-97. [PMID: 25582570 DOI: 10.1016/j.bbabio.2014.12.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 12/21/2014] [Indexed: 11/24/2022]
Abstract
Organellar gene expression (OGE) is crucial for plant development, respiration and photosynthesis, but the mechanisms that control it are still largely unclear. Thus, OGE requires various nucleus-encoded proteins that promote transcription, splicing, trimming and editing of organellar RNAs, and regulate their translation. In mammals, members of the mitochondrial transcription termination factor (mTERF) family play important roles in OGE. Intriguingly, three of the four mammalian mTERFs do not actually terminate transcription, as their designation suggests, but appear to function in antisense transcription termination and ribosome biogenesis. During the evolution of land plants, the mTERF family has expanded to approximately 30 members, but knowledge of their function in photosynthetic organisms remains sparse. Here, we review recent advances in the characterization of mterf mutants in mammals and photosynthetic organisms, focusing particularly on the progress made in elucidating their molecular functions in the last two years. This article is part of a Special Issue entitled: Chloroplast biogenesis.
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49
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Young REB, Purton S. Cytosine deaminase as a negative selectable marker for the microalgal chloroplast: a strategy for the isolation of nuclear mutations that affect chloroplast gene expression. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 80:915-25. [PMID: 25234691 PMCID: PMC4282525 DOI: 10.1111/tpj.12675] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/04/2014] [Accepted: 09/16/2014] [Indexed: 05/09/2023]
Abstract
Negative selectable markers are useful tools for forward-genetic screens aimed at identifying trans-acting factors that are required for expression of specific genes. Transgenic lines harbouring the marker fused to a gene element, such as a promoter, may be mutagenized to isolate loss-of-function mutants able to survive under selection. Such a strategy allows the molecular dissection of factors that are essential for expression of the gene. Expression of individual chloroplast genes in plants and algae typically requires one or more nuclear-encoded factors that act at the post-transcriptional level, often through interaction with the 5' UTR of the mRNA. To study such nuclear control further, we have developed the Escherichia coli cytosine deaminase gene codA as a conditional negative selectable marker for use in the model green alga Chlamydomonas reinhardtii. We show that a codon-optimized variant of codA with three amino acid substitutions confers sensitivity to 5-fluorocytosine (5-FC) when expressed in the chloroplast under the control of endogenous promoter/5' UTR elements from the photosynthetic genes psaA or petA. UV mutagenesis of the psaA transgenic line allowed recovery of 5-FC-resistant, photosynthetically deficient lines harbouring mutations in the nuclear gene for the factor TAA1 that is required for psaA translation. Similarly, the petA line was used to isolate mutants of the petA mRNA stability factor MCA1 and the translation factor TCA1. The codA marker may be used to identify critical residues in known nuclear factors and to aid the discovery of additional factors required for expression of chloroplast genes.
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Affiliation(s)
- Rosanna E B Young
- Algal Research Group, Institute of Structural and Molecular Biology, University College LondonGower Street, London, WC1E 6BT, UK
| | - Saul Purton
- Algal Research Group, Institute of Structural and Molecular Biology, University College LondonGower Street, London, WC1E 6BT, UK
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50
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Levey T, Westhoff P, Meierhoff K. Expression of a nuclear-encoded psbH gene complements the plastidic RNA processing defect in the PSII mutant hcf107 in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 80:292-304. [PMID: 25081859 DOI: 10.1111/tpj.12632] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/28/2014] [Accepted: 07/29/2014] [Indexed: 06/03/2023]
Abstract
The helical-repeat RNA-binding protein HCF107 is required for processing, stabilization and translation of plastid-encoded psbH mRNA. The psbH gene encodes a small, hydrophilic subunit of the PSII complex and is part of the plastidic psbB-psbT-psbH-petB-petD transcription unit. In Arabidopsis hcf107 mutants, only trace amounts of PSII proteins can be detected. Beside drastically reduced synthesis of PsbH, the synthesis of CP47 was also reduced in these mutants, although the corresponding psbB transcripts accumulate to wild type levels. This situation raises the question, whether the reduction of CP47 is a direct consequence of the mutation, based on targeting of HCF107 to the psbB mRNA, or a secondary affect due to the absent PsbH. To clarify this issue we introduced a chimeric psbH construct comprising a sequence encoding a chloroplast transit peptide into the hcf107-2 background. We found that the nucleus-localized psbH was able to complement the mutant defect resulting in photoautotrophic plants. The PSII proteins CP47 and D1 accumulated to barely half of the wild type level. Further experiments showed that cytosolically synthesized PsbH was imported into chloroplasts and assembled into PSII complexes. Using this approach, we showed that the tetratricopeptide repeat protein HCF107 of Arabidopsis is only responsible for expression of PsbH and not for synthesis of CP47. In addition the data suggest the necessity of the small, one-helix membrane spanning protein PsbH for the accumulation of CP47 in higher plants.
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Affiliation(s)
- Tatjana Levey
- Institut für Entwicklungs- und Molekularbiologie der Pflanzen, Heinrich-Heine-Universität, Universitätsstr. 1, 40225, Düsseldorf, Germany
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