1
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Kafri M, Patena W, Martin L, Wang L, Gomer G, Ergun SL, Sirkejyan AK, Goh A, Wilson AT, Gavrilenko SE, Breker M, Roichman A, McWhite CD, Rabinowitz JD, Cross FR, Wühr M, Jonikas MC. Systematic identification and characterization of genes in the regulation and biogenesis of photosynthetic machinery. Cell 2023; 186:5638-5655.e25. [PMID: 38065083 PMCID: PMC10760936 DOI: 10.1016/j.cell.2023.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 08/03/2023] [Accepted: 11/03/2023] [Indexed: 12/18/2023]
Abstract
Photosynthesis is central to food production and the Earth's biogeochemistry, yet the molecular basis for its regulation remains poorly understood. Here, using high-throughput genetics in the model eukaryotic alga Chlamydomonas reinhardtii, we identify with high confidence (false discovery rate [FDR] < 0.11) 70 poorly characterized genes required for photosynthesis. We then enable the functional characterization of these genes by providing a resource of proteomes of mutant strains, each lacking one of these genes. The data allow assignment of 34 genes to the biogenesis or regulation of one or more specific photosynthetic complexes. Further analysis uncovers biogenesis/regulatory roles for at least seven proteins, including five photosystem I mRNA maturation factors, the chloroplast translation factor MTF1, and the master regulator PMR1, which regulates chloroplast genes via nuclear-expressed factors. Our work provides a rich resource identifying regulatory and functional genes and placing them into pathways, thereby opening the door to a system-level understanding of photosynthesis.
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Affiliation(s)
- Moshe Kafri
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Weronika Patena
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Lance Martin
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Lianyong Wang
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Gillian Gomer
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Sabrina L Ergun
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08544, USA
| | - Arthur K Sirkejyan
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Audrey Goh
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Alexandra T Wilson
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Sophia E Gavrilenko
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Michal Breker
- Laboratory of Cell Cycle Genetics, The Rockefeller University, New York, NY 10021, USA
| | - Asael Roichman
- Lewis-Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Claire D McWhite
- Lewis-Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Joshua D Rabinowitz
- Lewis-Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Frederick R Cross
- Laboratory of Cell Cycle Genetics, The Rockefeller University, New York, NY 10021, USA
| | - Martin Wühr
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Martin C Jonikas
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08544, 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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Carrera-Pacheco SE, Hankamer B, Oey M. Environmental and nuclear influences on microalgal chloroplast gene expression. TRENDS IN PLANT SCIENCE 2023; 28:955-967. [PMID: 37080835 DOI: 10.1016/j.tplants.2023.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 03/09/2023] [Accepted: 03/18/2023] [Indexed: 05/03/2023]
Abstract
Microalgal chloroplasts, such as those of the model organism Chlamydomonas reinhardtii, are emerging as a new platform to produce recombinant proteins, including industrial enzymes, diagnostics, as well as animal and human therapeutics. Improving transgene expression and final recombinant protein yields, at laboratory and industrial scales, require optimization of both environmental and cellular factors. Most studies on C. reinhardtii have focused on optimization of cellular factors. Here, we review the regulatory influences of environmental factors, including light (cycle time, intensity, and quality), carbon source (CO2 and organic), and temperature. In particular, we summarize their influence via the redox state, cis-elements, and trans-factors on biomass and recombinant protein production to support the advancement of emerging large-scale light-driven biotechnology applications.
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Affiliation(s)
- Saskya E Carrera-Pacheco
- Centro de Investigación Biomédica (CENBIO), Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Quito 170527, Ecuador
| | - Ben Hankamer
- The University of Queensland, Institute for Molecular Bioscience, 306 Carmody Road, St Lucia, Australia.
| | - Melanie Oey
- The University of Queensland, Institute for Molecular Bioscience, 306 Carmody Road, St Lucia, Australia.
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4
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Fages‐Lartaud M, Hundvin K, Hohmann‐Marriott MF. Mechanisms governing codon usage bias and the implications for protein expression in the chloroplast of Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 112:919-945. [PMID: 36071273 PMCID: PMC9828097 DOI: 10.1111/tpj.15970] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/29/2022] [Accepted: 09/01/2022] [Indexed: 05/30/2023]
Abstract
Chloroplasts possess a considerably reduced genome that is decoded via an almost minimal set of tRNAs. These features make an excellent platform for gaining insights into fundamental mechanisms that govern protein expression. Here, we present a comprehensive and revised perspective of the mechanisms that drive codon selection in the chloroplast of Chlamydomonas reinhardtii and the functional consequences for protein expression. In order to extract this information, we applied several codon usage descriptors to genes with different expression levels. We show that highly expressed genes strongly favor translationally optimal codons, while genes with lower functional importance are rather affected by directional mutational bias. We demonstrate that codon optimality can be deduced from codon-anticodon pairing affinity and, for a small number of amino acids (leucine, arginine, serine, and isoleucine), tRNA concentrations. Finally, we review, analyze, and expand on the impact of codon usage on protein yield, secondary structures of mRNA, translation initiation and termination, and amino acid composition of proteins, as well as cotranslational protein folding. The comprehensive analysis of codon choice provides crucial insights into heterologous gene expression in the chloroplast of C. reinhardtii, which may also be applicable to other chloroplast-containing organisms and bacteria.
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Affiliation(s)
- Maxime Fages‐Lartaud
- Department of BiotechnologyNorwegian University of Science and TechnologyTrondheimN‐7491Norway
| | - Kristoffer Hundvin
- Department of BiotechnologyNorwegian University of Science and TechnologyTrondheimN‐7491Norway
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5
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Ma K, Deng L, Wu H, Fan J. Towards green biomanufacturing of high-value recombinant proteins using promising cell factory: Chlamydomonas reinhardtii chloroplast. BIORESOUR BIOPROCESS 2022; 9:83. [PMID: 38647750 PMCID: PMC10992328 DOI: 10.1186/s40643-022-00568-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/29/2022] [Indexed: 11/10/2022] Open
Abstract
Microalgae are cosmopolitan organisms in nature with short life cycles, playing a tremendous role in reducing the pressure of industrial carbon emissions. Besides, microalgae have the unique advantages of being photoautotrophic and harboring both prokaryotic and eukaryotic expression systems, becoming a popular host for recombinant proteins. Currently, numerous advanced molecular tools related to microalgal transgenesis have been explored and established, especially for the model species Chlamydomonas reinhardtii (C. reinhardtii hereafter). The development of genetic tools and the emergence of new strategies further increase the feasibility of developing C. reinhardtii chloroplasts as green factories, and the strong genetic operability of C. reinhardtii endows it with enormous potential as a synthetic biology platform. At present, C. reinhardtii chloroplasts could successfully produce plenty of recombinant proteins, including antigens, antibodies, antimicrobial peptides, protein hormones and enzymes. However, additional techniques and toolkits for chloroplasts need to be developed to achieve efficient and markerless editing of plastid genomes. Mining novel genetic elements and selectable markers will be more intensively studied in the future, and more factors affecting protein expression are urged to be explored. This review focuses on the latest technological progress of selectable markers for Chlamydomonas chloroplast genetic engineering and the factors that affect the efficiency of chloroplast protein expression. Furthermore, urgent challenges and prospects for future development are pointed out.
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Affiliation(s)
- Ke Ma
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Lei Deng
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Haizhen Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
- Department of Applied Biology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
| | - Jianhua Fan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
- Department of Applied Biology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
- School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, People's Republic of China.
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6
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Spaniol B, Lang J, Venn B, Schake L, Sommer F, Mustas M, Geimer S, Wollman FA, Choquet Y, Mühlhaus T, Schroda M. Complexome profiling on the Chlamydomonas lpa2 mutant reveals insights into PSII biogenesis and new PSII associated proteins. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:245-262. [PMID: 34436580 PMCID: PMC8730698 DOI: 10.1093/jxb/erab390] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 08/24/2021] [Indexed: 05/27/2023]
Abstract
While the composition and function of the major thylakoid membrane complexes are well understood, comparatively little is known about their biogenesis. The goal of this work was to shed more light on the role of auxiliary factors in the biogenesis of photosystem II (PSII). Here we have identified the homolog of LOW PSII ACCUMULATION 2 (LPA2) in Chlamydomonas. A Chlamydomonas reinhardtii lpa2 mutant grew slower in low light, was hypersensitive to high light, and exhibited aberrant structures in thylakoid membrane stacks. Chlorophyll fluorescence (Fv/Fm) was reduced by 38%. Synthesis and stability of newly made PSII core subunits D1, D2, CP43, and CP47 were not impaired. However, complexome profiling revealed that in the mutant CP43 was reduced to ~23% and D1, D2, and CP47 to ~30% of wild type levels. Levels of PSI and the cytochrome b6f complex were unchanged, while levels of the ATP synthase were increased by ~29%. PSII supercomplexes, dimers, and monomers were reduced to ~7%, ~26%, and ~60% of wild type levels, while RC47 was increased ~6-fold and LHCII by ~27%. We propose that LPA2 catalyses a step during PSII assembly without which PSII monomers and further assemblies become unstable and prone to degradation. The LHCI antenna was more disconnected from PSI in the lpa2 mutant, presumably as an adaptive response to reduce excitation of PSI. From the co-migration profiles of 1734 membrane-associated proteins, we identified three novel putative PSII associated proteins with potential roles in regulating PSII complex dynamics, assembly, and chlorophyll breakdown.
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Affiliation(s)
- Benjamin Spaniol
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Julia Lang
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Benedikt Venn
- Computational Systems Biology, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Lara Schake
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Frederik Sommer
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Matthieu Mustas
- Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, Institut de Biologie Physico-Chimique, UMR CNRS/UPMC 7141, Paris, France
| | - Stefan Geimer
- Zellbiologie/Elektronenmikroskopie, Universität Bayreuth, 95440 Bayreuth, Germany
| | - Francis-André Wollman
- Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, Institut de Biologie Physico-Chimique, UMR CNRS/UPMC 7141, Paris, France
| | - Yves Choquet
- Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, Institut de Biologie Physico-Chimique, UMR CNRS/UPMC 7141, Paris, France
| | - Timo Mühlhaus
- Computational Systems Biology, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Michael Schroda
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
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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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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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9
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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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10
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Macedo-Osorio KS, Martínez-Antonio A, Badillo-Corona JA. Pas de Trois: An Overview of Penta-, Tetra-, and Octo-Tricopeptide Repeat Proteins From Chlamydomonas reinhardtii and Their Role in Chloroplast Gene Expression. FRONTIERS IN PLANT SCIENCE 2021; 12:775366. [PMID: 34868174 PMCID: PMC8635915 DOI: 10.3389/fpls.2021.775366] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/26/2021] [Indexed: 05/05/2023]
Abstract
Penta-, Tetra-, and Octo-tricopeptide repeat (PPR, TPR, and OPR) proteins are nucleus-encoded proteins composed of tandem repeats of 35, 34, and 38-40 amino acids, respectively. They form helix-turn-helix structures that interact with mRNA or other proteins and participate in RNA stabilization, processing, maturation, and act as translation enhancers of chloroplast and mitochondrial mRNAs. These helical repeat proteins are unevenly present in plants and algae. While PPR proteins are more abundant in plants than in algae, OPR proteins are more abundant in algae. In Arabidopsis, maize, and rice there have been 450, 661, and 477 PPR proteins identified, respectively, which contrasts with only 14 PPR proteins identified in Chlamydomonas reinhardtii. Likewise, more than 120 OPR proteins members have been predicted from the nuclear genome of C. reinhardtii and only one has been identified in Arabidopsis thaliana. Due to their abundance in land plants, PPR proteins have been largely characterized making it possible to elucidate their RNA-binding code. This has even allowed researchers to generate engineered PPR proteins with defined affinity to a particular target, which has served as the basis to develop tools for gene expression in biotechnological applications. However, fine elucidation of the helical repeat proteins code in Chlamydomonas is a pending task. In this review, we summarize the current knowledge on the role PPR, TPR, and OPR proteins play in chloroplast gene expression in the green algae C. reinhardtii, pointing to relevant similarities and differences with their counterparts in plants. We also recapitulate on how these proteins have been engineered and shown to serve as mRNA regulatory factors for biotechnological applications in plants and how this could be used as a starting point for applications in algae.
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Affiliation(s)
- Karla S. Macedo-Osorio
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, México City, México
- Biological Engineering Laboratory, Genetic Engineering Department, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional-Unidad Irapuato, Irapuato, México
- División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Xochimilco, México City, México
- *Correspondence: Karla S. Macedo-Osorio,
| | - Agustino Martínez-Antonio
- Biological Engineering Laboratory, Genetic Engineering Department, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional-Unidad Irapuato, Irapuato, México
| | - Jesús A. Badillo-Corona
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, México City, México
- Jesús A. Badillo-Corona,
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11
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Hillebrand A, Matz JM, Almendinger M, Müller K, Matuschewski K, Schmitz-Linneweber C. Identification of clustered organellar short (cos) RNAs and of a conserved family of organellar RNA-binding proteins, the heptatricopeptide repeat proteins, in the malaria parasite. Nucleic Acids Res 2019; 46:10417-10431. [PMID: 30102371 PMCID: PMC6212722 DOI: 10.1093/nar/gky710] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 07/24/2018] [Indexed: 11/13/2022] Open
Abstract
Gene expression in mitochondria of Plasmodium falciparum is essential for parasite survival. The molecular mechanisms of Plasmodium organellar gene expression remain poorly understood. This includes the enigmatic assembly of the mitochondrial ribosome from highly fragmented rRNAs. Here, we present the identification of clustered organellar short RNA fragments (cosRNAs) that are possible footprints of RNA-binding proteins (RBPs) in Plasmodium organelles. In plants, RBPs of the pentatricopeptide repeat (PPR) class produce footprints as a consequence of their function in processing organellar RNAs. Intriguingly, many of the Plasmodium cosRNAs overlap with 5'-ends of rRNA fragments. We hypothesize that these are footprints of RBPs involved in assembling the rRNA fragments into a functioning ribosome. A bioinformatics search of the Plasmodium nuclear genome identified a hitherto unrecognized organellar helical-hairpin-repeat protein family that we term heptatricopeptide repeat (HPR) proteins. We demonstrate that selected HPR proteins are targeted to mitochondria in P. berghei and that one of them, PbHPR1, associates with RNA, but not DNA in vitro. A phylogenetic search identified HPR proteins in a wide variety of eukaryotes. We hypothesize that HPR proteins are required for processing and stabilizing RNAs in Apicomplexa and other taxa.
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Affiliation(s)
- Arne Hillebrand
- Humboldt University Berlin, Molecular Genetics, Berlin, Germany
| | - Joachim M Matz
- Humboldt University, Department of Molecular Parasitology, Berlin, Germany
| | | | - Katja Müller
- Humboldt University, Department of Molecular Parasitology, Berlin, Germany
| | - Kai Matuschewski
- Humboldt University, Department of Molecular Parasitology, Berlin, Germany
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12
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Viola S, Cavaiuolo M, Drapier D, Eberhard S, Vallon O, Wollman FA, Choquet Y. MDA1, a nucleus-encoded factor involved in the stabilization and processing of the atpA transcript in the chloroplast of Chlamydomonas. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:1033-1047. [PMID: 30809889 DOI: 10.1111/tpj.14300] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/11/2019] [Accepted: 02/18/2019] [Indexed: 05/21/2023]
Abstract
In Chlamydomonas reinhardtii, chloroplast gene expression is tightly regulated post-transcriptionally by gene-specific trans-acting protein factors. Here, we report the molecular identification of an OctotricoPeptide Repeat (OPR) protein, MDA1, which governs the maturation and accumulation of the atpA transcript, encoding subunit α of the chloroplast ATP synthase. As does TDA1, another OPR protein required for the translation of the atpA mRNA, MDA1 targets the atpA 5'-untranslated region (UTR). Unexpectedly, it binds within a region of approximately 100 nt in the middle of the atpA 5'-UTR, at variance with the stabilization factors characterized so far, which bind to the 5'-end of their target mRNA to protect it from 5' → 3' exonucleases. It binds the same region as TDA1, with which it forms a high-molecular-weight complex that also comprises the atpA mRNA. This complex dissociates upon translation, promoting degradation of the atpA mRNA. We suggest that atpA transcripts, once translated, enter the degradation pathway because they cannot reassemble with MDA1 and TDA1, which preferentially bind to de novo transcribed mRNAs.
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Affiliation(s)
- Stefania Viola
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste -UMR7141, IBPC, CNRS-Sorbonne Université, 13, rue Pierre et Marie Curie, 75005, Paris, France
| | - Marina Cavaiuolo
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste -UMR7141, IBPC, CNRS-Sorbonne Université, 13, rue Pierre et Marie Curie, 75005, Paris, France
| | - Dominique Drapier
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste -UMR7141, IBPC, CNRS-Sorbonne Université, 13, rue Pierre et Marie Curie, 75005, Paris, France
| | - Stephan Eberhard
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste -UMR7141, IBPC, CNRS-Sorbonne Université, 13, rue Pierre et Marie Curie, 75005, Paris, France
| | - Olivier Vallon
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste -UMR7141, IBPC, CNRS-Sorbonne Université, 13, rue Pierre et Marie Curie, 75005, Paris, France
| | - Francis-André Wollman
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste -UMR7141, IBPC, CNRS-Sorbonne Université, 13, rue Pierre et Marie Curie, 75005, Paris, France
| | - Yves Choquet
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste -UMR7141, IBPC, CNRS-Sorbonne Université, 13, rue Pierre et Marie Curie, 75005, Paris, France
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13
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Macedo-Osorio KS, Pérez-España VH, Garibay-Orijel C, Guzmán-Zapata D, Durán-Figueroa NV, Badillo-Corona JA. Intercistronic expression elements (IEE) from the chloroplast of Chlamydomonas reinhardtii can be used for the expression of foreign genes in synthetic operons. PLANT MOLECULAR BIOLOGY 2018; 98:303-317. [PMID: 30225747 DOI: 10.1007/s11103-018-0776-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 08/31/2018] [Indexed: 05/21/2023]
Abstract
Two intercistronic regions were identified as functional intercistronic expression elements (IEE) for the simultaneous expression of aphA-6 and gfp in a synthetic operon in the chloroplast of C. reinhardtii. Chlamydomonas reinhardtii, a biflagellate photosynthetic microalga, has been widely used in basic and applied science. Already three decades ago, Chlamydomonas had its chloroplast genome transformed and to this day constitutes the only alga routinely used in transplastomic technology. Despite the fact that over a 100 foreign genes have been expressed from the chloroplast genome, little has been done to address the challenge of expressing multiple genes in the form of operons, a development that is needed and crucial to push forward metabolic engineering and synthetic biology in this organism. Here, we studied five intercistronic regions and investigated if they can be used as intercistronic expression elements (IEE) in synthetic operons to drive the expression of foreign genes in the chloroplast of C. reinhardtii. The intercistronic regions were those from the psbB-psbT, psbN-psbH, psaC-petL, petL-trnN and tscA-chlN chloroplast operons, and the foreign genes were the aminoglycoside 3'-phosphotransferase (aphA-6), which confers resistance to kanamycin, and the green fluorescent protein gene (gfp). While all the intercistronic regions yielded lines that were resistant to kanamycin, only two (obtained with intercistronic regions from psbN-psbH and tscA-chlN) were identified as functional IEEs, yielding lines in which the second cistron (gfp) was translated and generated GFP. The IEEs we have identified could be useful for the stacking of genes for metabolic engineering or synthetic biology circuits in the chloroplast of C. reinhardtii.
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Affiliation(s)
- Karla S Macedo-Osorio
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto SN, Col. Barrio la Laguna Ticoman, Mexico City, Mexico
| | - Víctor H Pérez-España
- Universidad Autónoma del Estado de Hidalgo, Escuela Superior de Apan, Carretera Apan Calpulalpan km 8, Col. Chimalpa-Tlalayote, Apan, Hidalgo, Mexico
| | - Claudio Garibay-Orijel
- Labcitec, Camino a Atzacoalco 99, Col. Constitución de la República, Mexico City, Mexico
| | - Daniel Guzmán-Zapata
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto SN, Col. Barrio la Laguna Ticoman, Mexico City, Mexico
| | - Noé V Durán-Figueroa
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto SN, Col. Barrio la Laguna Ticoman, Mexico City, Mexico
| | - Jesús A Badillo-Corona
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto SN, Col. Barrio la Laguna Ticoman, Mexico City, Mexico.
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RNA-stabilization factors in chloroplasts of vascular plants. Essays Biochem 2018; 62:51-64. [PMID: 29453323 PMCID: PMC5897788 DOI: 10.1042/ebc20170061] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/02/2018] [Accepted: 01/12/2018] [Indexed: 12/23/2022]
Abstract
In contrast to the cyanobacterial ancestor, chloroplast gene expression is predominantly governed on the post-transcriptional level such as modifications of the RNA sequence, decay rates, exo- and endonucleolytic processing as well as translational events. The concerted function of numerous chloroplast RNA-binding proteins plays a fundamental and often essential role in all these processes but our understanding of their impact in regulation of RNA degradation is only at the beginning. Moreover, metabolic processes and post-translational modifications are thought to affect the function of RNA protectors. These protectors contain a variety of different RNA-recognition motifs, which often appear as multiple repeats. They are required for normal plant growth and development as well as diverse stress responses and acclimation processes. Interestingly, most of the protectors are plant specific which reflects a fast-evolving RNA metabolism in chloroplasts congruent with the diverging RNA targets. Here, we mainly focused on the characteristics of known chloroplast RNA-binding proteins that protect exonuclease-sensitive sites in chloroplasts of vascular plants.
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15
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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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16
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Boehm E, Zaganelli S, Maundrell K, Jourdain AA, Thore S, Martinou JC. FASTKD1 and FASTKD4 have opposite effects on expression of specific mitochondrial RNAs, depending upon their endonuclease-like RAP domain. Nucleic Acids Res 2017; 45:6135-6146. [PMID: 28335001 PMCID: PMC5449608 DOI: 10.1093/nar/gkx164] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 02/28/2017] [Indexed: 11/14/2022] Open
Abstract
FASTK family proteins have been identified as regulators of mitochondrial RNA homeostasis linked to mitochondrial diseases, but much remains unknown about these proteins. We show that CRISPR-mediated disruption of FASTKD1 increases ND3 mRNA level, while disruption of FASTKD4 reduces the level of ND3 and of other mature mRNAs including ND5 and CYB, and causes accumulation of ND5-CYB precursor RNA. Disrupting both FASTKD1 and FASTKD4 in the same cell results in decreased ND3 mRNA similar to the effect of depleting FASTKD4 alone, indicating that FASTKD4 loss is epistatic. Interestingly, very low levels of FASTKD4 are sufficient to prevent ND3 loss and ND5-CYB precursor accumulation, suggesting that FASTKD4 may act catalytically. Furthermore, structural modeling predicts that each RAP domain of FASTK proteins contains a nuclease fold with a conserved aspartate residue at the putative active site. Accordingly, mutation of this residue in FASTKD4 abolishes its function. Experiments with FASTK chimeras indicate that the RAP domain is essential for the function of the FASTK proteins, while the region upstream determines RNA targeting and protein localization. In conclusion, this paper identifies new aspects of FASTK protein biology and suggests that the RAP domain function depends on an intrinsic nucleolytic activity.
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Affiliation(s)
- Erik Boehm
- Cell Biology Department, University of Geneva, 1211 Geneva 4, Switzerland
| | - Sofia Zaganelli
- Cell Biology Department, University of Geneva, 1211 Geneva 4, Switzerland
| | - Kinsey Maundrell
- Cell Biology Department, University of Geneva, 1211 Geneva 4, Switzerland
| | - Alexis A Jourdain
- Cell Biology Department, University of Geneva, 1211 Geneva 4, Switzerland
| | - Stéphane Thore
- INSERM U-1212, CNRS UMR 5320, Université de Bordeaux, ARNA Laboratory, Bordeaux 33000, France
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17
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Cline SG, Laughbaum IA, Hamel PP. CCS2, an Octatricopeptide-Repeat Protein, Is Required for Plastid Cytochrome c Assembly in the Green Alga Chlamydomonas reinhardtii. FRONTIERS IN PLANT SCIENCE 2017. [PMID: 28824661 DOI: 10.3389/fpls.2017.0130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In bacteria and energy generating organelles, c-type cytochromes are a class of universal electron carriers with a heme cofactor covalently linked via one or two thioether bonds to a heme binding site. The covalent attachment of heme to apocytochromes is a catalyzed process, taking place via three evolutionarily distinct assembly pathways (Systems I, II, III). System II was discovered in the green alga Chlamydomonas reinhardtii through the genetic analysis of the ccs mutants (cytochrome csynthesis), which display a block in the apo- to holo- form conversion of cytochrome f and c6, the thylakoid lumen resident c-type cytochromes functioning in photosynthesis. Here we show that the gene corresponding to the CCS2 locus encodes a 1,719 amino acid polypeptide and identify the molecular lesions in the ccs2-1 to ccs2-5 alleles. The CCS2 protein displays seven degenerate amino acid repeats, which are variations of the octatricopeptide-repeat motif (OPR) recently recognized in several nuclear-encoded proteins controlling the maturation, stability, or translation of chloroplast transcripts. A plastid site of action for CCS2 is inferred from the finding that GFP fused to the first 100 amino acids of the algal protein localizes to chloroplasts in Nicotiana benthamiana. We discuss the possible functions of CCS2 in the heme attachment reaction.
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Affiliation(s)
- Sara G Cline
- Department of Molecular Genetics and Department of Biological Chemistry and Pharmacology, The Ohio State University, ColumbusOH, United States
- Plant Cellular and Molecular Biology Graduate Program, The Ohio State University, ColumbusOH, United States
| | - Isaac A Laughbaum
- Department of Molecular Genetics and Department of Biological Chemistry and Pharmacology, The Ohio State University, ColumbusOH, United States
| | - Patrice P Hamel
- Department of Molecular Genetics and Department of Biological Chemistry and Pharmacology, The Ohio State University, ColumbusOH, United States
- Plant Cellular and Molecular Biology Graduate Program, The Ohio State University, ColumbusOH, United States
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18
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Cline SG, Laughbaum IA, Hamel PP. CCS2, an Octatricopeptide-Repeat Protein, Is Required for Plastid Cytochrome c Assembly in the Green Alga Chlamydomonas reinhardtii. FRONTIERS IN PLANT SCIENCE 2017; 8:1306. [PMID: 28824661 PMCID: PMC5541062 DOI: 10.3389/fpls.2017.01306] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 07/12/2017] [Indexed: 05/19/2023]
Abstract
In bacteria and energy generating organelles, c-type cytochromes are a class of universal electron carriers with a heme cofactor covalently linked via one or two thioether bonds to a heme binding site. The covalent attachment of heme to apocytochromes is a catalyzed process, taking place via three evolutionarily distinct assembly pathways (Systems I, II, III). System II was discovered in the green alga Chlamydomonas reinhardtii through the genetic analysis of the ccs mutants (cytochrome csynthesis), which display a block in the apo- to holo- form conversion of cytochrome f and c6, the thylakoid lumen resident c-type cytochromes functioning in photosynthesis. Here we show that the gene corresponding to the CCS2 locus encodes a 1,719 amino acid polypeptide and identify the molecular lesions in the ccs2-1 to ccs2-5 alleles. The CCS2 protein displays seven degenerate amino acid repeats, which are variations of the octatricopeptide-repeat motif (OPR) recently recognized in several nuclear-encoded proteins controlling the maturation, stability, or translation of chloroplast transcripts. A plastid site of action for CCS2 is inferred from the finding that GFP fused to the first 100 amino acids of the algal protein localizes to chloroplasts in Nicotiana benthamiana. We discuss the possible functions of CCS2 in the heme attachment reaction.
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Affiliation(s)
- Sara G. Cline
- Department of Molecular Genetics and Department of Biological Chemistry and Pharmacology, The Ohio State University, ColumbusOH, United States
- Plant Cellular and Molecular Biology Graduate Program, The Ohio State University, ColumbusOH, United States
| | - Isaac A. Laughbaum
- Department of Molecular Genetics and Department of Biological Chemistry and Pharmacology, The Ohio State University, ColumbusOH, United States
| | - Patrice P. Hamel
- Department of Molecular Genetics and Department of Biological Chemistry and Pharmacology, The Ohio State University, ColumbusOH, United States
- Plant Cellular and Molecular Biology Graduate Program, The Ohio State University, ColumbusOH, United States
- *Correspondence: Patrice P. Hamel,
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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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20
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Wei H, Wang Z. Engineering RNA-binding proteins with diverse activities. WILEY INTERDISCIPLINARY REVIEWS-RNA 2015; 6:597-613. [DOI: 10.1002/wrna.1296] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 07/09/2015] [Accepted: 07/20/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Huanhuan Wei
- Key Laboratory of Computational Biology; MPG-CAS Partner Institute of Computational Biology; Shanghai China
| | - Zefeng Wang
- Key Laboratory of Computational Biology; MPG-CAS Partner Institute of Computational Biology; Shanghai China
- Department of Pharmacology; University of North Carolina at Chapel Hill; Chapel Hill NC USA
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21
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The Octatricopeptide Repeat Protein Raa8 Is Required for Chloroplast trans Splicing. EUKARYOTIC CELL 2015. [PMID: 26209695 DOI: 10.1128/ec.00096-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The mRNA maturation of the tripartite chloroplast psaA gene from the green alga Chlamydomonas reinhardtii depends on various nucleus-encoded factors that participate in trans splicing of two group II introns. Recently, a multiprotein complex was identified that is involved in processing the psaA precursor mRNA. Using coupled tandem affinity purification (TAP) and mass spectrometry analyses with the trans-splicing factor Raa4 as a bait protein, we recently identified a multisubunit ribonucleoprotein (RNP) complex comprising the previously characterized trans-splicing factors Raa1, Raa3, Raa4, and Rat2 plus novel components. Raa1 and Rat2 share a structural motif, an octatricopeptide repeat (OPR), that presumably functions as an RNA interaction module. Two of the novel RNP complex components also exhibit a predicted OPR motif and were therefore considered potential trans-splicing factors. In this study, we selected bacterial artificial chromosome (BAC) clones encoding these OPR proteins and conducted functional complementation assays using previously generated trans-splicing mutants. Our assay revealed that the trans-splicing defect of mutant F19 was restored by a new factor we named RAA8; molecular characterization of complemented strains verified that Raa8 participates in splicing of the first psaA group II intron. Three of six OPR motifs are located in the C-terminal end of Raa8, which was shown to be essential for restoring psaA mRNA trans splicing. Our results support the important role played by OPR proteins in chloroplast RNA metabolism and also demonstrate that combining TAP and mass spectrometry with functional complementation studies represents a vigorous tool for identifying trans-splicing factors.
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