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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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Das A, Subrahmanian N, Gabilly ST, Andrianova EP, Zhulin IB, Motohashi K, Hamel PP. Two disulfide-reducing pathways are required for the maturation of plastid c-type cytochromes in Chlamydomonas reinhardtii. Genetics 2023; 225:iyad155. [PMID: 37595062 PMCID: PMC10550313 DOI: 10.1093/genetics/iyad155] [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: 04/28/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 08/20/2023] Open
Abstract
In plastids, conversion of light energy into ATP relies on cytochrome f, a key electron carrier with a heme covalently attached to a CXXCH motif. Covalent heme attachment requires reduction of the disulfide-bonded CXXCH by CCS5 and CCS4. CCS5 receives electrons from the oxidoreductase CCDA, while CCS4 is a protein of unknown function. In Chlamydomonas reinhardtii, loss of CCS4 or CCS5 yields a partial cytochrome f assembly defect. Here, we report that the ccs4ccs5 double mutant displays a synthetic photosynthetic defect characterized by a complete loss of holocytochrome f assembly. This defect is chemically corrected by reducing agents, confirming the placement of CCS4 and CCS5 in a reducing pathway. CCS4-like proteins occur in the green lineage, and we show that HCF153, a distant ortholog from Arabidopsis thaliana, can substitute for Chlamydomonas CCS4. Dominant suppressor mutations mapping to the CCS4 gene were identified in photosynthetic revertants of the ccs4ccs5 mutants. The suppressor mutations yield changes in the stroma-facing domain of CCS4 that restore holocytochrome f assembly above the residual levels detected in ccs5. Because the CCDA protein accumulation is decreased specifically in the ccs4 mutant, we hypothesize the suppressor mutations enhance the supply of reducing power through CCDA in the absence of CCS5. We discuss the operation of a CCS5-dependent and a CCS5-independent pathway controlling the redox status of the heme-binding cysteines of apocytochrome f.
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Affiliation(s)
- Ankita Das
- Department of Molecular Genetics, The Ohio State University, 500 Aronoff Laboratory, 318 W. 12th Avenue, Columbus, OH 43210, USA
- Molecular Genetics Graduate Program, The Ohio State University, Columbus, OH 43210, USA
| | - Nitya Subrahmanian
- Department of Molecular Genetics, The Ohio State University, 500 Aronoff Laboratory, 318 W. 12th Avenue, Columbus, OH 43210, USA
| | - Stéphane T Gabilly
- Department of Molecular Genetics, The Ohio State University, 500 Aronoff Laboratory, 318 W. 12th Avenue, Columbus, OH 43210, USA
| | - Ekaterina P Andrianova
- Department of Microbiology and Translational Data Analytics Institute, The Ohio State University, 318 W. 12th Avenue, Columbus, OH 43210, USA
| | - Igor B Zhulin
- Department of Microbiology and Translational Data Analytics Institute, The Ohio State University, 318 W. 12th Avenue, Columbus, OH 43210, USA
| | - Ken Motohashi
- Department of Frontier Life Sciences, Kyoto Sangyo University, Karigamo Motoyama, Kita-ku, Kyoto 603-8047, Japan
| | - Patrice Paul Hamel
- Department of Molecular Genetics and Department of Biological Chemistry and Pharmacology, The Ohio State University, 500 Aronoff Laboratory, 318 W. 12th Avenue, Columbus, OH 43210, USA
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3
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Miró-Vinyals B, Artigues M, Wostrikoff K, Monte E, Broto-Puig F, Leivar P, Planas A. Chloroplast engineering of the green microalgae Chlamydomonas reinhardtii for the production of HAA, the lipid moiety of rhamnolipid biosurfactants. N Biotechnol 2023; 76:1-12. [PMID: 37004923 DOI: 10.1016/j.nbt.2023.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/25/2023] [Accepted: 03/30/2023] [Indexed: 04/03/2023]
Abstract
Hydroxyalkanoyloxyalkanoates (HAA) are lipidic surfactants with a number of potential applications, but more remarkably, they are the biosynthetic precursors of rhamnolipids (RL), which are preferred biosurfactants thanks to their excellent physicochemical properties, biological activities, and environmental biodegradability. Because the natural highest producer of RLs is the pathogenic bacterium Pseudomonas aeruginosa, important efforts have been dedicated to transfer production to heterologous non-pathogenic microorganisms. Unicellular photosynthetic microalgae are emerging as important hosts for sustainable industrial biotechnology due to their ability to transform CO2 efficiently into biomass and bioproducts of interest. Here, we have explored the potential of the eukaryotic green microalgae Chlamydomonas reinhardtii as a chassis to produce RLs. Chloroplast genome engineering allowed the stable functional expression of the gene encoding RhlA acyltransferase from P. aeruginosa, an enzyme catalyzing the condensation of two 3-hydroxyacyl acid intermediaries in the fatty acid synthase cycle, to produce HAA. Four congeners of varying chain lengths were identified and quantified by UHPLC-QTOF mass spectrometry and gas chromatography, including C10-C10 and C10-C8, and the less abundant C10-C12 and C10-C6 congeners. HAA was present in the intracellular fraction, but also showed increased accumulation in the extracellular medium. Moreover, HAA production was also observed under photoautotrophic conditions based on atmospheric CO2. These results establish that RhlA is active in the chloroplast and is able to produce a new pool of HAA in a eukaryotic host. Subsequent engineering of microalgal strains should contribute to the development of an alternative clean, safe and cost-effective platform for the sustainable production of RLs. DATA AVAILABILITY: The data that support the findings of this study are available from the corresponding authors upon reasonable request.
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Calderon RH, de Vitry C, Wollman FA, Niyogi KK. Rubredoxin 1 promotes the proper folding of D1 and is not required for heme b 559 assembly in Chlamydomonas photosystem II. J Biol Chem 2023; 299:102968. [PMID: 36736898 PMCID: PMC9986647 DOI: 10.1016/j.jbc.2023.102968] [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: 10/24/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 02/04/2023] Open
Abstract
Photosystem II (PSII), the water:plastoquinone oxidoreductase of oxygenic photosynthesis, contains a heme b559 iron whose axial ligands are provided by histidine residues from the α (PsbE) and β (PsbF) subunits. PSII assembly depends on accessory proteins that facilitate the step-wise association of its protein and pigment components into a functional complex, a process that is challenging to study due to the low accumulation of assembly intermediates. Here, we examined the putative role of the iron[1Fe-0S]-containing protein rubredoxin 1 (RBD1) as an assembly factor for cytochrome b559, using the RBD1-lacking 2pac mutant from Chlamydomonas reinhardtii, in which the accumulation of PSII was rescued by the inactivation of the thylakoid membrane FtsH protease. To this end, we constructed the double mutant 2pac ftsh1-1, which harbored PSII dimers that sustained its photoautotrophic growth. We purified PSII from the 2pac ftsh1-1 background and found that α and β cytochrome b559 subunits are still present and coordinate heme b559 as in the WT. Interestingly, immunoblot analysis of dark- and low light-grown 2pac ftsh1-1 showed the accumulation of a 23-kDa fragment of the D1 protein, a marker typically associated with structural changes resulting from photodamage of PSII. Its cleavage occurs in the vicinity of a nonheme iron which binds to PSII on its electron acceptor side. Altogether, our findings demonstrate that RBD1 is not required for heme b559 assembly and point to a role for RBD1 in promoting the proper folding of D1, possibly via delivery or reduction of the nonheme iron during PSII assembly.
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Affiliation(s)
- Robert H Calderon
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA; Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden.
| | - Catherine de Vitry
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, Paris, France
| | - Francis-André Wollman
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, Paris, France
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA; Howard Hughes Medical Institute, University of California, Berkeley, California, USA
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5
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Li N, Wong WS, Feng L, Wang C, Wong KS, Zhang N, Yang W, Jiang Y, Jiang L, He JX. The thylakoid membrane protein NTA1 is an assembly factor of the cytochrome b 6f complex essential for chloroplast development in Arabidopsis. PLANT COMMUNICATIONS 2023; 4:100509. [PMID: 36560880 PMCID: PMC9860185 DOI: 10.1016/j.xplc.2022.100509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/18/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
The cytochrome b6f (Cyt b6f) complex is a multisubunit protein complex in chloroplast thylakoid membranes required for photosynthetic electron transport. Here we report the isolation and characterization of the new tiny albino 1 (nta1) mutant in Arabidopsis, which has severe defects in Cyt b6f accumulation and chloroplast development. Gene cloning revealed that the nta1 phenotype was caused by disruption of a single nuclear gene, NTA1, which encodes an integral thylakoid membrane protein conserved across green algae and plants. Overexpression of NTA1 completely rescued the nta1 phenotype, and knockout of NTA1 in wild-type plants recapitulated the mutant phenotype. Loss of NTA1 function severely impaired the accumulation of multiprotein complexes related to photosynthesis in thylakoid membranes, particularly the components of Cyt b6f. NTA1 was shown to directly interact with four subunits (Cyt b6/PetB, PetD, PetG, and PetN) of Cyt b6f through the DUF1279 domain and C-terminal sequence to mediate their assembly. Taken together, our results identify NTA1 as a new and key regulator of chloroplast development that plays essential roles in assembly of the Cyt b6f complex by interacting with multiple Cyt b6f subunits.
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Affiliation(s)
- Na Li
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Wing Shing Wong
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Lei Feng
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Chunming Wang
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - King Shing Wong
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Nianhui Zhang
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Wei Yang
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Yueming Jiang
- Guangdong Provincial Key Laboratory of Applied Botany & Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Core Botanical Gardens, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Liwen Jiang
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Jun-Xian He
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
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6
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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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7
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Azarin K, Usatov A, Makarenko M, Kozel N, Kovalevich A, Dremuk I, Yemelyanova A, Logacheva M, Fedorenko A, Averina N. A point mutation in the photosystem I P700 chlorophyll a apoprotein A1 gene confers variegation in Helianthus annuus L. PLANT MOLECULAR BIOLOGY 2020; 103:373-389. [PMID: 32166486 DOI: 10.1007/s11103-020-00997-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 03/09/2020] [Indexed: 05/24/2023]
Abstract
Even a point mutation in the psaA gene mediates chlorophyll deficiency. The role of the plastid signal may perform the redox state of the compounds on the acceptor-side of PSI. Two extranuclear variegated mutants of sunflower, Var1 and Var33, were investigated. The yellow sectors of both mutants were characterized by an extremely low chlorophyll and carotenoid content, as well as poorly developed, unstacked thylakoid membranes. A full-genome sequencing of the cpDNA revealed mutations in the psaA gene in both Var1 and Var33. The cpDNA from the yellow sectors of Var1 differs from those in the wild type by only a single, non-synonymous substitution (Gly734Glu) in the psaA gene, which encodes a subunit of photosystem (PS) I. In the cpDNA from the yellow sectors of Var33, the single-nucleotide insertion in the psaA gene was revealed, leading to frameshift at the 580 amino acid position. Analysis of the photosynthetic electron transport demonstrated an inhibition of the PSI and PSII activities in the yellow tissues of the mutant plants. It has been suggested that mutations in the psaA gene of both Var1 and Var33 led to the disruption of PSI. Due to the non-functional PSI, photosynthetic electron transport is blocked, which, in turn, leads to photodamage of PSII. These data are confirmed by immunoblotting analysis, which showed a significant reduction in PsbA in the yellow leaf sectors, but not PsaA. The expression of chloroplast and nuclear genes encoding the PSI subunits (psaA, psaB, and PSAN), the PSII subunits (psbA, psbB, and PSBW), the antenna proteins (LHCA1, LHCB1, and LHCB4), the ribulose 1.5-bisphosphate carboxylase subunits (rbcL and RbcS), and enzymes of chlorophyll biosynthesis were down-regulated in the yellow leaf tissue. The extremely reduced transcriptional activity of the two protochlorophyllide oxidoreductase (POR) genes involved in chlorophyll biosynthesis is noteworthy. The disruption of NADPH synthesis, due to the non-functional PSI, probably led to a significant reduction in NADPH-protochlorophyllide oxidoreductase in the yellow sectors of Var1 and Var33. A dramatic decrease in chlorophyllide was shown in the yellow sectors. A reduction in NADPH-protochlorophyllide oxidoreductase, along with photodegradation, has been suggested as a result of chlorophyll deficiency.
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Affiliation(s)
- Kirill Azarin
- Southern Federal University, Rostov-on-Don, Russian Federation.
| | | | - Maksim Makarenko
- Southern Federal University, Rostov-on-Don, Russian Federation
- Institute for Information Transmission Problems, Moscow, Russian Federation
| | - Nikolay Kozel
- Institute of Biophysics and Cell Engineering, National Academy of Sciences of Belarus, Minsk, Belarus
| | | | - Irina Dremuk
- Institute of Biophysics and Cell Engineering, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Anna Yemelyanova
- Institute of Biophysics and Cell Engineering, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Mariya Logacheva
- Institute for Information Transmission Problems, Moscow, Russian Federation
- Skolkovo Institute of Science and Technology, Moscow, Russian Federation
| | | | - Nataliya Averina
- Institute of Biophysics and Cell Engineering, National Academy of Sciences of Belarus, Minsk, Belarus
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8
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Ozawa SI, Cavaiuolo M, Jarrige D, Kuras R, Rutgers M, Eberhard S, Drapier D, Wollman FA, Choquet Y. The OPR Protein MTHI1 Controls the Expression of Two Different Subunits of ATP Synthase CFo in Chlamydomonas reinhardtii. THE PLANT CELL 2020; 32:1179-1203. [PMID: 31988263 PMCID: PMC7145495 DOI: 10.1105/tpc.19.00770] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/02/2020] [Accepted: 01/27/2020] [Indexed: 05/19/2023]
Abstract
In the green alga Chlamydomonas (Chlamydomonas r einhardtii), chloroplast gene expression is tightly regulated posttranscriptionally by gene-specific trans-acting protein factors. Here, we report the identification of the octotricopeptide repeat protein MTHI1, which is critical for the biogenesis of chloroplast ATP synthase oligomycin-sensitive chloroplast coupling factor. Unlike most trans-acting factors characterized so far in Chlamydomonas, which control the expression of a single gene, MTHI1 targets two distinct transcripts: it is required for the accumulation and translation of atpH mRNA, encoding a subunit of the selective proton channel, but it also enhances the translation of atpI mRNA, which encodes the other subunit of the channel. MTHI1 targets the 5' untranslated regions of both the atpH and atpI genes. Coimmunoprecipitation and small RNA sequencing revealed that MTHI1 binds specifically a sequence highly conserved among Chlorophyceae and the Ulvale clade of Ulvophyceae at the 5' end of triphosphorylated atpH mRNA. A very similar sequence, located ∼60 nucleotides upstream of the atpI initiation codon, was also found in some Chlorophyceae and Ulvale algae species and is essential for atpI mRNA translation in Chlamydomonas. Such a dual-targeted trans-acting factor provides a means to coregulate the expression of the two proton hemi-channels.
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Affiliation(s)
- Shin-Ichiro Ozawa
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Marina Cavaiuolo
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Domitille Jarrige
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Richard Kuras
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Mark Rutgers
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Stephan Eberhard
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Dominique Drapier
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Francis-André Wollman
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Yves Choquet
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique and Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
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9
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Majeran W, Wostrikoff K, Wollman FA, Vallon O. Role of ClpP in the Biogenesis and Degradation of RuBisCO and ATP Synthase in Chlamydomonas reinhardtii. PLANTS (BASEL, SWITZERLAND) 2019; 8:E191. [PMID: 31248038 PMCID: PMC6681370 DOI: 10.3390/plants8070191] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 01/17/2023]
Abstract
Ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) associates a chloroplast- and a nucleus-encoded subunit (LSU and SSU). It constitutes the major entry point of inorganic carbon into the biosphere as it catalyzes photosynthetic CO2 fixation. Its abundance and richness in sulfur-containing amino acids make it a prime source of N and S during nutrient starvation, when photosynthesis is downregulated and a high RuBisCO level is no longer needed. Here we show that translational attenuation of ClpP1 in the green alga Chlamydomonas reinhardtii results in retarded degradation of RuBisCO during S- and N-starvation, suggesting that the Clp protease is a major effector of RubisCO degradation in these conditions. Furthermore, we show that ClpP cannot be attenuated in the context of rbcL point mutations that prevent LSU folding. The mutant LSU remains in interaction with the chloroplast chaperonin complex. We propose that degradation of the mutant LSU by the Clp protease is necessary to prevent poisoning of the chaperonin. In the total absence of LSU, attenuation of ClpP leads to a dramatic stabilization of unassembled SSU, indicating that Clp is responsible for its degradation. In contrast, attenuation of ClpP in the absence of SSU does not lead to overaccumulation of LSU, whose translation is controlled by assembly. Altogether, these results point to RuBisCO degradation as one of the major house-keeping functions of the essential Clp protease. In addition, we show that non-assembled subunits of the ATP synthase are also stabilized when ClpP is attenuated. In the case of the atpA-FUD16 mutation, this can even allow the assembly of a small amount of CF1, which partially restores phototrophy.
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Affiliation(s)
- Wojciech Majeran
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, Université Paris-Diderot, Université Paris-Sud, INRA, Université Evry, Université Paris-Saclay, Rue de Noetzlin, 91190 Gif-sur-Yvette, France.
| | - Katia Wostrikoff
- UMR7141 CNRS/Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Francis-André Wollman
- UMR7141 CNRS/Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Olivier Vallon
- UMR7141 CNRS/Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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10
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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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11
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Brzezowski P, Ksas B, Havaux M, Grimm B, Chazaux M, Peltier G, Johnson X, Alric J. The function of PROTOPORPHYRINOGEN IX OXIDASE in chlorophyll biosynthesis requires oxidised plastoquinone in Chlamydomonas reinhardtii. Commun Biol 2019; 2:159. [PMID: 31069268 PMCID: PMC6499784 DOI: 10.1038/s42003-019-0395-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 03/20/2019] [Indexed: 12/23/2022] Open
Abstract
In the last common enzymatic step of tetrapyrrole biosynthesis, prior to the branching point leading to the biosynthesis of heme and chlorophyll, protoporphyrinogen IX (Protogen) is oxidised to protoporphyrin IX (Proto) by protoporphyrinogen IX oxidase (PPX). The absence of thylakoid-localised plastid terminal oxidase 2 (PTOX2) and cytochrome b6f complex in the ptox2 petB mutant, results in almost complete reduction of the plastoquinone pool (PQ pool) in light. Here we show that the lack of oxidised PQ impairs PPX function, leading to accumulation and subsequently uncontrolled oxidation of Protogen to non-metabolised Proto. Addition of 3(3,4-Dichlorophenyl)-1,1-dimethylurea (DCMU) prevents the over-reduction of the PQ pool in ptox2 petB and decreases Proto accumulation. This observation strongly indicates the need of oxidised PQ as the electron acceptor for the PPX reaction in Chlamydomonas reinhardtii. The PPX-PQ pool interaction is proposed to function as a feedback loop between photosynthetic electron transport and chlorophyll biosynthesis.
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Affiliation(s)
- Pawel Brzezowski
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- Humboldt-Universität zu Berlin, Institut für Biologie/Pflanzenphysiologie, 10115 Berlin, Germany
| | - Brigitte Ksas
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire d’Ecophysiologie Moléculaire des Plantes, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Michel Havaux
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire d’Ecophysiologie Moléculaire des Plantes, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Bernhard Grimm
- Humboldt-Universität zu Berlin, Institut für Biologie/Pflanzenphysiologie, 10115 Berlin, Germany
| | - Marie Chazaux
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Gilles Peltier
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Xenie Johnson
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Jean Alric
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
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12
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Simkin AJ, López-Calcagno PE, Raines CA. Feeding the world: improving photosynthetic efficiency for sustainable crop production. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1119-1140. [PMID: 30772919 PMCID: PMC6395887 DOI: 10.1093/jxb/ery445] [Citation(s) in RCA: 207] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/27/2018] [Indexed: 05/18/2023]
Abstract
A number of recent studies have provided strong support demonstrating that improving the photosynthetic processes through genetic engineering can provide an avenue to improve yield potential. The major focus of this review is on improvement of the Calvin-Benson cycle and electron transport. Consideration is also given to how altering regulatory process may provide an additional route to increase photosynthetic efficiency. Here we summarize some of the recent successes that have been observed through genetic manipulation of photosynthesis, showing that, in both the glasshouse and the field, yield can be increased by >40%. These results provide a clear demonstration of the potential for increasing yield through improvements in photosynthesis. In the final section, we consider the need to stack improvement in photosynthetic traits with traits that target the yield gap in order to provide robust germplasm for different crops across the globe.
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Affiliation(s)
- Andrew J Simkin
- NIAB EMR, New Road, East Malling, Kent, UK
- School of Biological Sciences, Wivenhoe Park, University of Essex, Colchester, UK
| | | | - Christine A Raines
- School of Biological Sciences, Wivenhoe Park, University of Essex, Colchester, UK
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13
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De Mia M, Lemaire SD, Choquet Y, Wollman FA. Nitric Oxide Remodels the Photosynthetic Apparatus upon S-Starvation in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2019; 179:718-731. [PMID: 30530737 PMCID: PMC6426411 DOI: 10.1104/pp.18.01164] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 11/20/2018] [Indexed: 05/02/2023]
Abstract
Many photosynthetic autotrophs have evolved responses that adjust their metabolism to limitations in nutrient availability. Here we report a detailed characterization of the remodeling of photosynthesis upon sulfur starvation under heterotrophy and photo-autotrophy in the green alga (Chlamydomonas reinhardtii). Photosynthetic inactivation under low light and darkness is achieved through specific degradation of Rubisco and cytochrome b 6 f and occurs only in the presence of reduced carbon in the medium. The process is likely regulated by nitric oxide (NO), which is produced 24 h after the onset of starvation, as detected with NO-sensitive fluorescence probes visualized by fluorescence microscopy. We provide pharmacological evidence that intracellular NO levels govern this degradation pathway: the addition of a NO scavenger decreases the rate of cytochrome b 6 f and Rubisco degradation, whereas NO donors accelerate the degradation. Based on our analysis of the relative contribution of the different NO synthesis pathways, we conclude that the NO2-dependent nitrate reductase-independent pathway is crucial for NO production under sulfur starvation. Our data argue for an active role for NO in the remodeling of thylakoid protein complexes upon sulfur starvation.
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Affiliation(s)
- Marcello De Mia
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Stéphane D Lemaire
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Yves Choquet
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Francis-André Wollman
- Laboratoire de Physiologie Membranaire et Moléculaire du Chloroplaste, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 75005 Paris, France
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14
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Dumas L, Zito F, Auroy P, Johnson X, Peltier G, Alric J. Structure-Function Analysis of Chloroplast Proteins via Random Mutagenesis Using Error-Prone PCR. PLANT PHYSIOLOGY 2018; 177:465-475. [PMID: 29703866 PMCID: PMC6001340 DOI: 10.1104/pp.17.01618] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 03/31/2018] [Indexed: 05/14/2023]
Abstract
Site-directed mutagenesis of chloroplast genes was developed three decades ago and has greatly advanced the field of photosynthesis research. Here, we describe a new approach for generating random chloroplast gene mutants that combines error-prone polymerase chain reaction of a gene of interest with chloroplast complementation of the knockout Chlamydomonas reinhardtii mutant. As a proof of concept, we targeted a 300-bp sequence of the petD gene that encodes subunit IV of the thylakoid membrane-bound cytochrome b6f complex. By sequencing chloroplast transformants, we revealed 149 mutations in the 300-bp target petD sequence that resulted in 92 amino acid substitutions in the 100-residue target subunit IV sequence. Our results show that this method is suited to the study of highly hydrophobic, multisubunit, and chloroplast-encoded proteins containing cofactors such as hemes, iron-sulfur clusters, and chlorophyll pigments. Moreover, we show that mutant screening and sequencing can be used to study photosynthetic mechanisms or to probe the mutational robustness of chloroplast-encoded proteins, and we propose that this method is a valuable tool for the directed evolution of enzymes in the chloroplast.
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Affiliation(s)
- Louis Dumas
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Aix-Marseille Université, Unité Mixte de Recherche 7265, BIAM, Commissariat à l'Energie Atomique Cadarache, 13115 Saint-Paul-lez-Durance, France
| | - Francesca Zito
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Institut de Biologie Physico-Chimique, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7099, University Paris Diderot, Sorbonne Paris Cité, PSL Research University, F-75005 Paris, France
| | - Pascaline Auroy
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Aix-Marseille Université, Unité Mixte de Recherche 7265, BIAM, Commissariat à l'Energie Atomique Cadarache, 13115 Saint-Paul-lez-Durance, France
| | - Xenie Johnson
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Aix-Marseille Université, Unité Mixte de Recherche 7265, BIAM, Commissariat à l'Energie Atomique Cadarache, 13115 Saint-Paul-lez-Durance, France
| | - Gilles Peltier
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Aix-Marseille Université, Unité Mixte de Recherche 7265, BIAM, Commissariat à l'Energie Atomique Cadarache, 13115 Saint-Paul-lez-Durance, France
| | - Jean Alric
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Aix-Marseille Université, Unité Mixte de Recherche 7265, BIAM, Commissariat à l'Energie Atomique Cadarache, 13115 Saint-Paul-lez-Durance, France jean.alric@cea
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15
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Wittkopp TM, Saroussi S, Yang W, Johnson X, Kim RG, Heinnickel ML, Russell JJ, Phuthong W, Dent RM, Broeckling CD, Peers G, Lohr M, Wollman FA, Niyogi KK, Grossman AR. GreenCut protein CPLD49 of Chlamydomonas reinhardtii associates with thylakoid membranes and is required for cytochrome b 6 f complex accumulation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:1023-1037. [PMID: 29602195 DOI: 10.1111/tpj.13915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/23/2018] [Accepted: 03/06/2018] [Indexed: 06/08/2023]
Abstract
The GreenCut encompasses a suite of nucleus-encoded proteins with orthologs among green lineage organisms (plants, green algae), but that are absent or poorly conserved in non-photosynthetic/heterotrophic organisms. In Chlamydomonas reinhardtii, CPLD49 (Conserved in Plant Lineage and Diatoms49) is an uncharacterized GreenCut protein that is critical for maintaining normal photosynthetic function. We demonstrate that a cpld49 mutant has impaired photoautotrophic growth under high-light conditions. The mutant exhibits a nearly 90% reduction in the level of the cytochrome b6 f complex (Cytb6 f), which impacts linear and cyclic electron transport, but does not compromise the ability of the strain to perform state transitions. Furthermore, CPLD49 strongly associates with thylakoid membranes where it may be part of a membrane protein complex with another GreenCut protein, CPLD38; a mutant null for CPLD38 also impacts Cytb6 f complex accumulation. We investigated several potential functions of CPLD49, with some suggested by protein homology. Our findings are congruent with the hypothesis that CPLD38 and CPLD49 are part of a novel thylakoid membrane complex that primarily modulates accumulation, but also impacts the activity of the Cytb6 f complex. Based on motifs of CPLD49 and the activities of other CPLD49-like proteins, we suggest a role for this putative dehydrogenase in the synthesis of a lipophilic thylakoid membrane molecule or cofactor that influences the assembly and activity of Cytb6 f.
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Affiliation(s)
- Tyler M Wittkopp
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Shai Saroussi
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Wenqiang Yang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Xenie Johnson
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, Saint Paul lez Durance, France
| | - Rick G Kim
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Mark L Heinnickel
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - James J Russell
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Witchukorn Phuthong
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Rachel M Dent
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Corey D Broeckling
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, CO, 80523, USA
| | - Graham Peers
- Department of Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Martin Lohr
- Institut für Molekulare Physiologie - Pflanzenbiochemie, Johannes Gutenberg-Universität, 55099, Mainz, Germany
| | | | - Krishna K Niyogi
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
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16
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Zoschke R, Bock R. Chloroplast Translation: Structural and Functional Organization, Operational Control, and Regulation. THE PLANT CELL 2018; 30:745-770. [PMID: 29610211 PMCID: PMC5969280 DOI: 10.1105/tpc.18.00016] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/26/2018] [Accepted: 04/01/2018] [Indexed: 05/20/2023]
Abstract
Chloroplast translation is essential for cellular viability and plant development. Its positioning at the intersection of organellar RNA and protein metabolism makes it a unique point for the regulation of gene expression in response to internal and external cues. Recently obtained high-resolution structures of plastid ribosomes, the development of approaches allowing genome-wide analyses of chloroplast translation (i.e., ribosome profiling), and the discovery of RNA binding proteins involved in the control of translational activity have greatly increased our understanding of the chloroplast translation process and its regulation. In this review, we provide an overview of the current knowledge of the chloroplast translation machinery, its structure, organization, and function. In addition, we summarize the techniques that are currently available to study chloroplast translation and describe how translational activity is controlled and which cis-elements and trans-factors are involved. Finally, we discuss how translational control contributes to the regulation of chloroplast gene expression in response to developmental, environmental, and physiological cues. We also illustrate the commonalities and the differences between the chloroplast and bacterial translation machineries and the mechanisms of protein biosynthesis in these two prokaryotic systems.
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Affiliation(s)
- Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Ralph Bock
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
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17
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Liponska A, Jamalli A, Kuras R, Suay L, Garbe E, Wollman FA, Laalami S, Putzer H. Tracking the elusive 5' exonuclease activity of Chlamydomonas reinhardtii RNase J. PLANT MOLECULAR BIOLOGY 2018; 96:641-653. [PMID: 29600502 DOI: 10.1007/s11103-018-0720-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 03/14/2018] [Indexed: 06/08/2023]
Abstract
Chlamydomonas RNase J is the first member of this enzyme family that has endo- but no intrinsic 5' exoribonucleolytic activity. This questions its proposed role in chloroplast mRNA maturation. RNA maturation and stability in the chloroplast are controlled by nuclear-encoded ribonucleases and RNA binding proteins. Notably, mRNA 5' end maturation is thought to be achieved by the combined action of a 5' exoribonuclease and specific pentatricopeptide repeat proteins (PPR) that block the progression of the nuclease. In Arabidopsis the 5' exo- and endoribonuclease RNase J has been implicated in this process. Here, we verified the chloroplast localization of the orthologous Chlamydomonas (Cr) RNase J and studied its activity, both in vitro and in vivo in a heterologous B. subtilis system. Our data show that Cr RNase J has endo- but no significant intrinsic 5' exonuclease activity that would be compatible with its proposed role in mRNA maturation. This is the first example of an RNase J ortholog that does not possess a 5' exonuclease activity. A yeast two-hybrid screen revealed a number of potential interaction partners but three of the most promising candidates tested, failed to induce the latent exonuclease activity of Cr RNase J. We still favor the hypothesis that Cr RNase J plays an important role in RNA metabolism, but our findings suggest that it rather acts as an endoribonuclease in the chloroplast.
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Affiliation(s)
- Anna Liponska
- CNRS UMR8261 - Université Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Ailar Jamalli
- CNRS UMR8261 - Université Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France
- Laboratory Science Research Center, Golestan University of Medical Sciences, Gorgan, Iran
| | - Richard Kuras
- CNRS UMR7141 (Associated with Université Pierre et Marie Curie), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Loreto Suay
- CNRS UMR7141 (Associated with Université Pierre et Marie Curie), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Enrico Garbe
- CNRS UMR8261 - Université Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Francis-André Wollman
- CNRS UMR7141 (Associated with Université Pierre et Marie Curie), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Soumaya Laalami
- CNRS UMR8261 - Université Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Harald Putzer
- CNRS UMR8261 - Université Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005, Paris, France.
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18
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Dumas L, Zito F, Blangy S, Auroy P, Johnson X, Peltier G, Alric J. A stromal region of cytochrome b6f subunit IV is involved in the activation of the Stt7 kinase in Chlamydomonas. Proc Natl Acad Sci U S A 2017; 114:12063-12068. [PMID: 29078388 PMCID: PMC5692589 DOI: 10.1073/pnas.1713343114] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The cytochrome (cyt) b6f complex and Stt7 kinase regulate the antenna sizes of photosystems I and II through state transitions, which are mediated by a reversible phosphorylation of light harvesting complexes II, depending on the redox state of the plastoquinone pool. When the pool is reduced, the cyt b6f activates the Stt7 kinase through a mechanism that is still poorly understood. After random mutagenesis of the chloroplast petD gene, coding for subunit IV of the cyt b6f complex, and complementation of a ΔpetD host strain by chloroplast transformation, we screened for impaired state transitions in vivo by chlorophyll fluorescence imaging. We show that residues Asn122, Tyr124, and Arg125 in the stromal loop linking helices F and G of cyt b6f subunit IV are crucial for state transitions. In vitro reconstitution experiments with purified cyt b6f and recombinant Stt7 kinase domain show that cyt b6f enhances Stt7 autophosphorylation and that the Arg125 residue is directly involved in this process. The peripheral stromal structure of the cyt b6f complex had, until now, no reported function. Evidence is now provided of a direct interaction with Stt7 on the stromal side of the membrane.
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Affiliation(s)
- Louis Dumas
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Aix-Marseille Université, UMR 7265, Institut de Biosciences et Biotechnologies d'Aix-Marseille, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France
| | - Francesca Zito
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Institut de Biologie Physico-Chimique, CNRS, UMR7099, University Paris Diderot, Sorbonne Paris Cité, Paris Sciences et Lettres Research University, F-75005 Paris, France
| | - Stéphanie Blangy
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Aix-Marseille Université, UMR 7265, Institut de Biosciences et Biotechnologies d'Aix-Marseille, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France
| | - Pascaline Auroy
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Aix-Marseille Université, UMR 7265, Institut de Biosciences et Biotechnologies d'Aix-Marseille, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France
| | - Xenie Johnson
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Aix-Marseille Université, UMR 7265, Institut de Biosciences et Biotechnologies d'Aix-Marseille, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France
| | - Gilles Peltier
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Aix-Marseille Université, UMR 7265, Institut de Biosciences et Biotechnologies d'Aix-Marseille, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France
| | - Jean Alric
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Aix-Marseille Université, UMR 7265, Institut de Biosciences et Biotechnologies d'Aix-Marseille, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France;
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Simkin AJ, McAusland L, Lawson T, Raines CA. Overexpression of the RieskeFeS Protein Increases Electron Transport Rates and Biomass Yield. PLANT PHYSIOLOGY 2017; 175:134-145. [PMID: 28754840 DOI: 10.1101/133702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/27/2017] [Indexed: 05/22/2023]
Abstract
In this study, we generated transgenic Arabidopsis (Arabidopsis thaliana) plants overexpressing the Rieske FeS protein (PetC), a component of the cytochrome b6f (cyt b6f) complex. Increasing the levels of this protein resulted in concomitant increases in the levels of cyt f (PetA) and cyt b6 (PetB), core proteins of the cyt b6f complex. Interestingly, an increase in the levels of proteins in both the photosystem I (PSI) and PSII complexes also was seen in the Rieske FeS overexpression plants. Although the mechanisms leading to these changes remain to be identified, the transgenic plants presented here provide novel tools to explore this. Importantly, overexpression of the Rieske FeS protein resulted in substantial and significant impacts on the quantum efficiency of PSI and PSII, electron transport, biomass, and seed yield in Arabidopsis plants. These results demonstrate the potential for manipulating electron transport processes to increase crop productivity.
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Affiliation(s)
- Andrew J Simkin
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Lorna McAusland
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Tracy Lawson
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Christine A Raines
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
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20
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Simkin AJ, McAusland L, Lawson T, Raines CA. Overexpression of the RieskeFeS Protein Increases Electron Transport Rates and Biomass Yield. PLANT PHYSIOLOGY 2017; 175:134-145. [PMID: 28754840 PMCID: PMC5580758 DOI: 10.1104/pp.17.00622] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/27/2017] [Indexed: 05/18/2023]
Abstract
In this study, we generated transgenic Arabidopsis (Arabidopsis thaliana) plants overexpressing the Rieske FeS protein (PetC), a component of the cytochrome b6f (cyt b6f) complex. Increasing the levels of this protein resulted in concomitant increases in the levels of cyt f (PetA) and cyt b6 (PetB), core proteins of the cyt b6f complex. Interestingly, an increase in the levels of proteins in both the photosystem I (PSI) and PSII complexes also was seen in the Rieske FeS overexpression plants. Although the mechanisms leading to these changes remain to be identified, the transgenic plants presented here provide novel tools to explore this. Importantly, overexpression of the Rieske FeS protein resulted in substantial and significant impacts on the quantum efficiency of PSI and PSII, electron transport, biomass, and seed yield in Arabidopsis plants. These results demonstrate the potential for manipulating electron transport processes to increase crop productivity.
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Affiliation(s)
- Andrew J Simkin
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Lorna McAusland
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Tracy Lawson
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Christine A Raines
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
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21
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Redesigning the Q A binding site of Photosystem II allows reduction of exogenous quinones. Nat Commun 2017; 8:15274. [PMID: 28466860 PMCID: PMC5418674 DOI: 10.1038/ncomms15274] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 03/10/2017] [Indexed: 01/13/2023] Open
Abstract
Strategies to harness photosynthesis from living organisms to generate electrical power have long been considered, yet efficiency remains low. Here, we aimed to reroute photosynthetic electron flow in photosynthetic organisms without compromising their phototrophic properties. We show that 2,6-dimethyl-p-benzoquinone (DMBQ) can be used as an electron mediator to assess the efficiency of mutations designed to engineer a novel electron donation pathway downstream of the primary electron acceptor QA of Photosystem (PS) II in the green alga Chlamydomonas reinhardtii. Through the use of structural prediction studies and a screen of site-directed PSII mutants we show that modifying the environment of the QA site increases the reduction rate of DMBQ. Truncating the C-terminus of the PsbT subunit protruding in the stroma provides evidence that shortening the distance between QA and DMBQ leads to sustained electron transfer to DMBQ, as confirmed by chronoamperometry, consistent with a bypass of the natural QA°− to QB pathway. Devices that harness electron flow from photosynthetic organisms generally compromise host photosynthesis. Here, the authors show that, by redesigning the QA site of Photosystem II, it is possible to reroute electrons to an exogenous quinone while maintaining endogenous photosynthetic electron transfer in a green alga.
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22
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Responses of the picoprasinophyte Micromonas commoda to light and ultraviolet stress. PLoS One 2017; 12:e0172135. [PMID: 28278262 PMCID: PMC5344333 DOI: 10.1371/journal.pone.0172135] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 01/31/2017] [Indexed: 11/19/2022] Open
Abstract
Micromonas is a unicellular marine green alga that thrives from tropical to polar ecosystems. We investigated the growth and cellular characteristics of acclimated mid-exponential phase Micromonas commoda RCC299 over multiple light levels and over the diel cycle (14:10 hour light:dark). We also exposed the light:dark acclimated M. commoda to experimental shifts from moderate to high light (HL), and to HL plus ultraviolet radiation (HL+UV), 4.5 hours into the light period. Cellular responses of this prasinophyte were quantified by flow cytometry and changes in gene expression by qPCR and RNA-seq. While proxies for chlorophyll a content and cell size exhibited similar diel variations in HL and controls, with progressive increases during day and decreases at night, both parameters sharply decreased after the HL+UV shift. Two distinct transcriptional responses were observed among chloroplast genes in the light shift experiments: i) expression of transcription and translation-related genes decreased over the time course, and this transition occurred earlier in treatments than controls; ii) expression of several photosystem I and II genes increased in HL relative to controls, as did the growth rate within the same diel period. However, expression of these genes decreased in HL+UV, likely as a photoprotective mechanism. RNA-seq also revealed two genes in the chloroplast genome, ycf2-like and ycf1-like, that had not previously been reported. The latter encodes the second largest chloroplast protein in Micromonas and has weak homology to plant Ycf1, an essential component of the plant protein translocon. Analysis of several nuclear genes showed that the expression of LHCSR2, which is involved in non-photochemical quenching, and five light-harvesting-like genes, increased 30 to >50-fold in HL+UV, but was largely unchanged in HL and controls. Under HL alone, a gene encoding a novel nitrite reductase fusion protein (NIRFU) increased, possibly reflecting enhanced N-assimilation under the 625 μmol photons m-2 s-1 supplied in the HL treatment. NIRFU’s domain structure suggests it may have more efficient electron transfer than plant NIR proteins. Our analyses indicate that Micromonas can readily respond to abrupt environmental changes, such that strong photoinhibition was provoked by combined exposure to HL and UV, but a ca. 6-fold increase in light was stimulatory.
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Tabatabaei I, Ruf S, Bock R. A bifunctional aminoglycoside acetyltransferase/phosphotransferase conferring tobramycin resistance provides an efficient selectable marker for plastid transformation. PLANT MOLECULAR BIOLOGY 2017; 93:269-281. [PMID: 27858324 PMCID: PMC5306187 DOI: 10.1007/s11103-016-0560-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 11/10/2016] [Indexed: 05/22/2023]
Abstract
KEY MESSAGE A new selectable marker gene for stable transformation of the plastid genome was developed that is similarly efficient as the aadA, and produces no background of spontaneous resistance mutants. More than 25 years after its development for Chlamydomonas and tobacco, the transformation of the chloroplast genome still represents a challenging technology that is available only in a handful of species. The vast majority of chloroplast transformation experiments conducted thus far have relied on a single selectable marker gene, the spectinomycin resistance gene aadA. Although a few alternative markers have been reported, the aadA has remained unrivalled in efficiency and is, therefore, nearly exclusively used. The development of new marker genes for plastid transformation is of crucial importance to all efforts towards extending the species range of the technology as well as to those applications in basic research, biotechnology and synthetic biology that involve the multistep engineering of plastid genomes. Here, we have tested a bifunctional resistance gene for its suitability as a selectable marker for chloroplast transformation. The bacterial enzyme aminoglycoside acetyltransferase(6')-Ie/aminoglycoside phosphotransferase(2″)-Ia possesses an N-terminal acetyltransferase domain and a C-terminal phosphotransferase domain that can act synergistically and detoxify aminoglycoside antibiotics highly efficiently. We report that, in combination with selection for resistance to the aminoglycoside tobramycin, the aac(6')-Ie/aph(2″)-Ia gene represents an efficient marker for plastid transformation in that it produces similar numbers of transplastomic lines as the spectinomycin resistance gene aadA. Importantly, no spontaneous antibiotic resistance mutants appear under tobramycin selection.
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Affiliation(s)
- Iman Tabatabaei
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
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24
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Wang F, Qi Y, Malnoë A, Choquet Y, Wollman FA, de Vitry C. The High Light Response and Redox Control of Thylakoid FtsH Protease in Chlamydomonas reinhardtii. MOLECULAR PLANT 2017; 10:99-114. [PMID: 27702692 DOI: 10.1016/j.molp.2016.09.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/07/2016] [Accepted: 09/17/2016] [Indexed: 05/23/2023]
Abstract
In Chlamydomonas reinhardtii, the major protease involved in the maintenance of photosynthetic machinery in thylakoid membranes, the FtsH protease, mostly forms large hetero-oligomers (∼1 MDa) comprising FtsH1 and FtsH2 subunits, whatever the light intensity for growth. Upon high light exposure, the FtsH subunits display a shorter half-life, which is counterbalanced by an increase in FTSH1/2 mRNA levels, resulting in the modest upregulation of FtsH1/2 proteins. Furthermore, we found that high light increases the protease activity through a hitherto unnoticed redox-controlled reduction of intermolecular disulfide bridges. We isolated a Chlamydomonas FTSH1 promoter-deficient mutant, ftsh1-3, resulting from the insertion of a TOC1 transposon, in which the high light-induced upregulation of FTSH1 gene expression is largely lost. In ftsh1-3, the abundance of FtsH1 and FtsH2 proteins are loosely coupled (decreased by 70% and 30%, respectively) with no formation of large and stable homo-oligomers. Using strains exhibiting different accumulation levels of the FtsH1 subunit after complementation of ftsh1-3, we demonstrate that high light tolerance is tightly correlated with the abundance of the FtsH protease. Thus, the response of Chlamydomonas to light stress involves higher levels of FtsH1/2 subunits associated into large complexes with increased proteolytic activity.
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Affiliation(s)
- Fei Wang
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Paris 75005, France
| | - Yafei Qi
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Paris 75005, France
| | - Alizée Malnoë
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Paris 75005, France
| | - Yves Choquet
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Paris 75005, France
| | - Francis-André Wollman
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Paris 75005, France
| | - Catherine de Vitry
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Paris 75005, France.
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25
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Sun Y, Zerges W. Translational regulation in chloroplasts for development and homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:809-20. [PMID: 25988717 DOI: 10.1016/j.bbabio.2015.05.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 04/13/2015] [Accepted: 05/10/2015] [Indexed: 11/16/2022]
Abstract
Chloroplast genomes encode 100-200 proteins which function in photosynthesis, the organellar genetic system, and other pathways and processes. These proteins are synthesized by a complete translation system within the chloroplast, with bacterial-type ribosomes and translation factors. Here, we review translational regulation in chloroplasts, focusing on changes in translation rates which occur in response to requirements for proteins encoded by the chloroplast genome for development and homeostasis. In addition, we delineate the developmental and physiological contexts and model organisms in which translational regulation in chloroplasts has been studied. This article is part of a Special Issue entitled: Chloroplast biogenesis.
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Affiliation(s)
- Yi Sun
- Biology Department and Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke W., Montreal, Quebec H4B 1R6, Canada
| | - William Zerges
- Biology Department and Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke W., Montreal, Quebec H4B 1R6, Canada.
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26
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Schöttler MA, Tóth SZ, Boulouis A, Kahlau S. Photosynthetic complex stoichiometry dynamics in higher plants: biogenesis, function, and turnover of ATP synthase and the cytochrome b6f complex. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2373-400. [PMID: 25540437 DOI: 10.1093/jxb/eru495] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
During plant development and in response to fluctuating environmental conditions, large changes in leaf assimilation capacity and in the metabolic consumption of ATP and NADPH produced by the photosynthetic apparatus can occur. To minimize cytotoxic side reactions, such as the production of reactive oxygen species, photosynthetic electron transport needs to be adjusted to the metabolic demand. The cytochrome b6f complex and chloroplast ATP synthase form the predominant sites of photosynthetic flux control. Accordingly, both respond strongly to changing environmental conditions and metabolic states. Usually, their contents are strictly co-regulated. Thereby, the capacity for proton influx into the lumen, which is controlled by electron flux through the cytochrome b6f complex, is balanced with proton efflux through ATP synthase, which drives ATP synthesis. We discuss the environmental, systemic, and metabolic signals triggering the stoichiometry adjustments of ATP synthase and the cytochrome b6f complex. The contribution of transcriptional and post-transcriptional regulation of subunit synthesis, and the importance of auxiliary proteins required for complex assembly in achieving the stoichiometry adjustments is described. Finally, current knowledge on the stability and turnover of both complexes is summarized.
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Affiliation(s)
- Mark Aurel Schöttler
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Szilvia Z Tóth
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Alix Boulouis
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Sabine Kahlau
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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27
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Boulouis A, Drapier D, Razafimanantsoa H, Wostrikoff K, Tourasse NJ, Pascal K, Girard-Bascou J, Vallon O, Wollman FA, Choquet Y. Spontaneous dominant mutations in chlamydomonas highlight ongoing evolution by gene diversification. THE PLANT CELL 2015; 27:984-1001. [PMID: 25804537 PMCID: PMC4558696 DOI: 10.1105/tpc.15.00010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 02/10/2015] [Accepted: 03/05/2015] [Indexed: 05/04/2023]
Abstract
We characterized two spontaneous and dominant nuclear mutations in the unicellular alga Chlamydomonas reinhardtii, ncc1 and ncc2 (for nuclear control of chloroplast gene expression), which affect two octotricopeptide repeat (OPR) proteins encoded in a cluster of paralogous genes on chromosome 15. Both mutations cause a single amino acid substitution in one OPR repeat. As a result, the mutated NCC1 and NCC2 proteins now recognize new targets that we identified in the coding sequences of the chloroplast atpA and petA genes, respectively. Interaction of the mutated proteins with these targets leads to transcript degradation; however, in contrast to the ncc1 mutation, the ncc2 mutation requires on-going translation to promote the decay of the petA mRNA. Thus, these mutants reveal a mechanism by which nuclear factors act on chloroplast mRNAs in Chlamydomonas. They illustrate how diversifying selection can allow cells to adapt the nuclear control of organelle gene expression to environmental changes. We discuss these data in the wider context of the evolution of regulation by helical repeat proteins.
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Affiliation(s)
- Alix Boulouis
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Dominique Drapier
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Hélène Razafimanantsoa
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Katia Wostrikoff
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Nicolas J Tourasse
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Kevin Pascal
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Jacqueline Girard-Bascou
- 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
| | - 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
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28
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Song Y, Ci D, Tian M, Zhang D. Comparison of the physiological effects and transcriptome responses of Populus simonii under different abiotic stresses. PLANT MOLECULAR BIOLOGY 2014; 86:139-56. [PMID: 25002226 DOI: 10.1007/s11103-014-0218-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 06/15/2014] [Indexed: 05/21/2023]
Abstract
In the field, perennial plants such as poplar (Populus spp.) must adapt to simultaneous exposure to various abiotic stresses, which can affect their growth and survival. However, the mechanisms for stress-specific adaption in response to different abiotic stresses remain unclear. Thus, understanding the unique acclimation process for each abiotic treatment will require a comprehensive and systematic comparison of the responses of poplar to different abiotic stresses. To compare the responses to multiple stresses, we compared physiological effects and transcriptome changes in poplar under four abiotic stresses (salinity, osmotic, heat and cold). Photosynthesis and antioxidant enzymes changed significantly after 6 h abiotic stress treatment. Therefore, using 6 h abiotic stress treatment groups for transcriptome analysis, we identified a set of 863 differentially expressed genes (653 up-regulated and 210 down-regulated) common to osmotic, salinity, heat and cold treatment. We also identified genes specific to osmotic (1,739), salinity (1,222), cold (2,508) and heat (3,200), revealing that salinity stress has the fewest differently-expressed genes. After gene annotation, we found differences in expression of genes related to electron transport, stomatal control, antioxidant enzymes, cell wall alteration, and phytohormone biosynthesis and signaling in response to various abiotic stresses. This study provides new insights to improve our understanding of the mechanisms by which poplar adapts under different abiotic stress conditions and provides new clues for further studies.
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Affiliation(s)
- Yuepeng Song
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, People's Republic of China,
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29
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Hojka M, Thiele W, Tóth SZ, Lein W, Bock R, Schöttler MA. Inducible Repression of Nuclear-Encoded Subunits of the Cytochrome b6f Complex in Tobacco Reveals an Extraordinarily Long Lifetime of the Complex. PLANT PHYSIOLOGY 2014; 165:1632-1646. [PMID: 24963068 PMCID: PMC4119044 DOI: 10.1104/pp.114.243741] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 06/24/2014] [Indexed: 05/18/2023]
Abstract
The biogenesis of the cytochrome b6f complex in tobacco (Nicotiana tabacum) seems to be restricted to young leaves, suggesting a high lifetime of the complex. To directly determine its lifetime, we employed an ethanol-inducible RNA interference (RNAi) approach targeted against the essential nuclear-encoded Rieske protein (PetC) and the small M subunit (PetM), whose function in higher plants is unknown. Young expanding leaves of both PetM and PetC RNAi transformants bleached rapidly and developed necroses, while mature leaves, whose photosynthetic apparatus was fully assembled before RNAi induction, stayed green. In line with these phenotypes, cytochrome b6f complex accumulation and linear electron transport capacity were strongly repressed in young leaves of both RNAi transformants, showing that the M subunit is as essential for cytochrome b6f complex accumulation as the Rieske protein. In mature leaves, all photosynthetic parameters were indistinguishable from the wild type even after 14 d of induction. As RNAi repression of PetM and PetC was highly efficient in both young and mature leaves, these data indicate a lifetime of the cytochrome b6f complex of at least 1 week. The switch-off of cytochrome b6f complex biogenesis in mature leaves may represent part of the first dedicated step of the leaf senescence program.
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Affiliation(s)
- Marta Hojka
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Wolfram Thiele
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Szilvia Z Tóth
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Wolfgang Lein
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Mark Aurel Schöttler
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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30
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Mungpakdee S, Shinzato C, Takeuchi T, Kawashima T, Koyanagi R, Hisata K, Tanaka M, Goto H, Fujie M, Lin S, Satoh N, Shoguchi E. Massive gene transfer and extensive RNA editing of a symbiotic dinoflagellate plastid genome. Genome Biol Evol 2014; 6:1408-22. [PMID: 24881086 PMCID: PMC4079212 DOI: 10.1093/gbe/evu109] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Genome sequencing of Symbiodinium minutum revealed that 95 of 109 plastid-associated genes have been transferred to the nuclear genome and subsequently expanded by gene duplication. Only 14 genes remain in plastids and occur as DNA minicircles. Each minicircle (1.8–3.3 kb) contains one gene and a conserved noncoding region containing putative promoters and RNA-binding sites. Nine types of RNA editing, including a novel G/U type, were discovered in minicircle transcripts but not in genes transferred to the nucleus. In contrast to DNA editing sites in dinoflagellate mitochondria, which tend to be highly conserved across all taxa, editing sites employed in DNA minicircles are highly variable from species to species. Editing is crucial for core photosystem protein function. It restores evolutionarily conserved amino acids and increases peptidyl hydropathy. It also increases protein plasticity necessary to initiate photosystem complex assembly.
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Affiliation(s)
- Sutada Mungpakdee
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Chuya Shinzato
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Takeshi Takeuchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Takeshi Kawashima
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Ryo Koyanagi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, JapanDNA Sequencing Section, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Kanako Hisata
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Makiko Tanaka
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Hiroki Goto
- DNA Sequencing Section, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Manabu Fujie
- DNA Sequencing Section, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Senjie Lin
- Department of Marine Sciences, University of Connecticut
| | - Nori Satoh
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Japan
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Tomizioli M, Lazar C, Brugière S, Burger T, Salvi D, Gatto L, Moyet L, Breckels LM, Hesse AM, Lilley KS, Seigneurin-Berny D, Finazzi G, Rolland N, Ferro M. Deciphering thylakoid sub-compartments using a mass spectrometry-based approach. Mol Cell Proteomics 2014; 13:2147-67. [PMID: 24872594 DOI: 10.1074/mcp.m114.040923] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Photosynthesis has shaped atmospheric and ocean chemistries and probably changed the climate as well, as oxygen is released from water as part of the photosynthetic process. In photosynthetic eukaryotes, this process occurs in the chloroplast, an organelle containing the most abundant biological membrane, the thylakoids. The thylakoids of plants and some green algae are structurally inhomogeneous, consisting of two main domains: the grana, which are piles of membranes gathered by stacking forces, and the stroma-lamellae, which are unstacked thylakoids connecting the grana. The major photosynthetic complexes are unevenly distributed within these compartments because of steric and electrostatic constraints. Although proteomic analysis of thylakoids has been instrumental to define its protein components, no extensive proteomic study of subthylakoid localization of proteins in the BBY (grana) and the stroma-lamellae fractions has been achieved so far. To fill this gap, we performed a complete survey of the protein composition of these thylakoid subcompartments using thylakoid membrane fractionations. We employed semiquantitative proteomics coupled with a data analysis pipeline and manual annotation to differentiate genuine BBY and stroma-lamellae proteins from possible contaminants. About 300 thylakoid (or potentially thylakoid) proteins were shown to be enriched in either the BBY or the stroma-lamellae fractions. Overall, present findings corroborate previous observations obtained for photosynthetic proteins that used nonproteomic approaches. The originality of the present proteomic relies in the identification of photosynthetic proteins whose differential distribution in the thylakoid subcompartments might explain already observed phenomenon such as LHCII docking. Besides, from the present localization results we can suggest new molecular actors for photosynthesis-linked activities. For instance, most PsbP-like subunits being differently localized in stroma-lamellae, these proteins could be linked to the PSI-NDH complex in the context of cyclic electron flow around PSI. In addition, we could identify about a hundred new likely minor thylakoid (or chloroplast) proteins, some of them being potential regulators of the chloroplast physiology.
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Affiliation(s)
- Martino Tomizioli
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; §CNRS, UMR5168, F-38054 Grenoble, France; ¶CEA, iRTSV, Laboratoire Physiologie Cellulaire & Végétale, F-38054 Grenoble, France; ‖INRA, USC 1359, F-38054 Grenoble, France
| | - Cosmin Lazar
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; **CEA, iRTSV, Laboratoire Biologie à Grande Echelle, F-38054 Grenoble, France; ‡‡ INSERM, U1038, F-38054 Grenoble, France
| | - Sabine Brugière
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; **CEA, iRTSV, Laboratoire Biologie à Grande Echelle, F-38054 Grenoble, France; ‡‡ INSERM, U1038, F-38054 Grenoble, France
| | - Thomas Burger
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; **CEA, iRTSV, Laboratoire Biologie à Grande Echelle, F-38054 Grenoble, France; ‡‡ INSERM, U1038, F-38054 Grenoble, France; §§CNRS, FR3425, F-38054 Grenoble, France
| | - Daniel Salvi
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; §CNRS, UMR5168, F-38054 Grenoble, France; ¶CEA, iRTSV, Laboratoire Physiologie Cellulaire & Végétale, F-38054 Grenoble, France; ‖INRA, USC 1359, F-38054 Grenoble, France
| | - Laurent Gatto
- ¶¶Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, CB2 1QR, United Kingdom
| | - Lucas Moyet
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; §CNRS, UMR5168, F-38054 Grenoble, France; ¶CEA, iRTSV, Laboratoire Physiologie Cellulaire & Végétale, F-38054 Grenoble, France; ‖INRA, USC 1359, F-38054 Grenoble, France
| | - Lisa M Breckels
- ¶¶Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, CB2 1QR, United Kingdom
| | - Anne-Marie Hesse
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; **CEA, iRTSV, Laboratoire Biologie à Grande Echelle, F-38054 Grenoble, France; ‡‡ INSERM, U1038, F-38054 Grenoble, France
| | - Kathryn S Lilley
- ¶¶Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, CB2 1QR, United Kingdom
| | - Daphné Seigneurin-Berny
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; §CNRS, UMR5168, F-38054 Grenoble, France; ¶CEA, iRTSV, Laboratoire Physiologie Cellulaire & Végétale, F-38054 Grenoble, France; ‖INRA, USC 1359, F-38054 Grenoble, France
| | - Giovanni Finazzi
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; §CNRS, UMR5168, F-38054 Grenoble, France; ¶CEA, iRTSV, Laboratoire Physiologie Cellulaire & Végétale, F-38054 Grenoble, France; ‖INRA, USC 1359, F-38054 Grenoble, France
| | - Norbert Rolland
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; §CNRS, UMR5168, F-38054 Grenoble, France; ¶CEA, iRTSV, Laboratoire Physiologie Cellulaire & Végétale, F-38054 Grenoble, France; ‖INRA, USC 1359, F-38054 Grenoble, France;
| | - Myriam Ferro
- From the ‡Univ. Grenoble Alpes, F-38000 Grenoble, France; **CEA, iRTSV, Laboratoire Biologie à Grande Echelle, F-38054 Grenoble, France; ‡‡ INSERM, U1038, F-38054 Grenoble, France;
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32
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Wei L, Derrien B, Gautier A, Houille-Vernes L, Boulouis A, Saint-Marcoux D, Malnoë A, Rappaport F, de Vitry C, Vallon O, Choquet Y, Wollman FA. Nitric oxide-triggered remodeling of chloroplast bioenergetics and thylakoid proteins upon nitrogen starvation in Chlamydomonas reinhardtii. THE PLANT CELL 2014; 26:353-72. [PMID: 24474630 PMCID: PMC3963581 DOI: 10.1105/tpc.113.120121] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/04/2013] [Accepted: 01/10/2014] [Indexed: 05/18/2023]
Abstract
Starving microalgae for nitrogen sources is commonly used as a biotechnological tool to boost storage of reduced carbon into starch granules or lipid droplets, but the accompanying changes in bioenergetics have been little studied so far. Here, we report that the selective depletion of Rubisco and cytochrome b6f complex that occurs when Chlamydomonas reinhardtii is starved for nitrogen in the presence of acetate and under normoxic conditions is accompanied by a marked increase in chlororespiratory enzymes, which converts the photosynthetic thylakoid membrane into an intracellular matrix for oxidative catabolism of reductants. Cytochrome b6f subunits and most proteins specifically involved in their biogenesis are selectively degraded, mainly by the FtsH and Clp chloroplast proteases. This regulated degradation pathway does not require light, active photosynthesis, or state transitions but is prevented when respiration is impaired or under phototrophic conditions. We provide genetic and pharmacological evidence that NO production from intracellular nitrite governs this degradation pathway: Addition of a NO scavenger and of two distinct NO producers decrease and increase, respectively, the rate of cytochrome b6f degradation; NO-sensitive fluorescence probes, visualized by confocal microscopy, demonstrate that nitrogen-starved cells produce NO only when the cytochrome b6f degradation pathway is activated.
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Affiliation(s)
- Lili Wei
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Benoit Derrien
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Arnaud Gautier
- École Normale Supérieure,
Département de Chimie, Unité Mixte de Recherche, CNRS–Ecole
Normale Supérieure–Université Pierre et Marie Curie 8640,
75231 Paris Cedex 05, France
| | - Laura Houille-Vernes
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Alix Boulouis
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Denis Saint-Marcoux
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Alizée Malnoë
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Fabrice Rappaport
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Catherine de Vitry
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Olivier Vallon
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Yves Choquet
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
| | - Francis-André Wollman
- Unité Mixte de Recherche 7141,
CNRS/Université Pierre et Marie Curie, Institut de Biologie
Physico-Chimique, F-75005 Paris, France
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Malnoë A, Wang F, Girard-Bascou J, Wollman FA, de Vitry C. Thylakoid FtsH protease contributes to photosystem II and cytochrome b6f remodeling in Chlamydomonas reinhardtii under stress conditions. THE PLANT CELL 2014; 26:373-90. [PMID: 24449688 PMCID: PMC3963582 DOI: 10.1105/tpc.113.120113] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 11/28/2013] [Accepted: 12/18/2013] [Indexed: 05/18/2023]
Abstract
FtsH is the major thylakoid membrane protease found in organisms performing oxygenic photosynthesis. Here, we show that FtsH from Chlamydomonas reinhardtii forms heterooligomers comprising two subunits, FtsH1 and FtsH2. We characterized this protease using FtsH mutants that we identified through a genetic suppressor approach that restored phototrophic growth of mutants originally defective for cytochrome b6f accumulation. We thus extended the spectrum of FtsH substrates in the thylakoid membranes beyond photosystem II, showing the susceptibility of cytochrome b6f complexes (and proteins involved in the ci heme binding pathway to cytochrome b6) to FtsH. We then show how FtsH is involved in the response of C. reinhardtii to macronutrient stress. Upon phosphorus starvation, photosynthesis inactivation results from an FtsH-sensitive photoinhibition process. In contrast, we identified an FtsH-dependent loss of photosystem II and cytochrome b6f complexes in darkness upon sulfur deprivation. The D1 fragmentation pattern observed in the latter condition was similar to that observed in photoinhibitory conditions, which points to a similar degradation pathway in these two widely different environmental conditions. Our experiments thus provide extensive evidence that FtsH plays a major role in the quality control of thylakoid membrane proteins and in the response of C. reinhardtii to light and macronutrient stress.
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34
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Chi W, Ma J, Zhang L. Regulatory factors for the assembly of thylakoid membrane protein complexes. Philos Trans R Soc Lond B Biol Sci 2013; 367:3420-9. [PMID: 23148269 DOI: 10.1098/rstb.2012.0065] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Major multi-protein photosynthetic complexes, located in thylakoid membranes, are responsible for the capture of light and its conversion into chemical energy in oxygenic photosynthetic organisms. Although the structures and functions of these photosynthetic complexes have been explored, the molecular mechanisms underlying their assembly remain elusive. In this review, we summarize current knowledge of the regulatory components involved in the assembly of thylakoid membrane protein complexes in photosynthetic organisms. Many of the known regulatory factors are conserved between prokaryotes and eukaryotes, whereas others appear to be newly evolved or to have expanded predominantly in eukaryotes. Their specific features and fundamental differences in cyanobacteria, green algae and land plants are discussed.
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Affiliation(s)
- Wei Chi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, People's Republic of China
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35
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Transmembrane signaling and assembly of the cytochrome b6f-lipidic charge transfer complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:1295-308. [PMID: 23507619 DOI: 10.1016/j.bbabio.2013.03.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 02/27/2013] [Accepted: 03/06/2013] [Indexed: 12/30/2022]
Abstract
Structure-function properties of the cytochrome b6f complex are sufficiently unique compared to those of the cytochrome bc1 complex that b6f should not be considered a trivially modified bc1 complex. A unique property of the dimeric b6f complex is its involvement in transmembrane signaling associated with the p-side oxidation of plastoquinol. Structure analysis of lipid binding sites in the cyanobacterial b6f complex prepared by hydrophobic chromatography shows that the space occupied by the H transmembrane helix in the cytochrome b subunit of the bc1 complex is mostly filled by a lipid in the b6f crystal structure. It is suggested that this space can be filled by the domain of a transmembrane signaling protein. The identification of lipid sites and likely function defines the intra-membrane conserved central core of the b6f complex, consisting of the seven trans-membrane helices of the cytochrome b and subunit IV polypeptides. The other six TM helices, contributed by cytochrome f, the iron-sulfur protein, and the four peripheral single span subunits, define a peripheral less conserved domain of the complex. The distribution of conserved and non-conserved domains of each monomer of the complex, and the position and inferred function of a number of the lipids, suggests a model for the sequential assembly in the membrane of the eight subunits of the b6f complex, in which the assembly is initiated by formation of the cytochrome b6-subunit IV core sub-complex in a monomer unit. Two conformations of the unique lipidic chlorophyll a, defined in crystal structures, are described, and functions of the outlying β-carotene, a possible 'latch' in supercomplex formation, are discussed. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes.
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36
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Suzuki Y, Makino A. Translational downregulation of RBCL is operative in the coordinated expression of Rubisco genes in senescent leaves in rice. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:1145-52. [PMID: 23349140 PMCID: PMC3580822 DOI: 10.1093/jxb/ers398] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Rubisco gene expression was examined in detail in rice (Oryza sativa L.) leaves at different positions, i.e. expanding, mature, and senescent leaves. Rubisco small subunit (RBCS) synthesis and RBCS mRNA levels were maximal in expanding leaves and gradually became lower in mature and senescent leaves, with declines in those of the large subunit (RBCL) being relatively slower. The amount of synthesized RBCL per unit level of RBCL mRNA and polysome loading of RBCL mRNA declined in senescent leaves, whereas such phenomena were not observed for RBCS. These results suggested that gene expression of RBCL is downregulated at the level of its translation when a balance between RBCL and RBCS expression is disturbed by leaf senescence. It has been suggested that RBCS protein is a positive regulator for RBCL mRNA level in expanding rice leaves, as judged from their stoichiometric relationship in RBCS transgenic rice plants. However, the ratio of the RBCL mRNA level to the amount of synthesized RBCS in senescent leaves was significantly higher than that in expanding leaves. Therefore, it is suggested that the decline in RBCL mRNA level in senescent leaves is not fully accounted for by that in the amount of synthesized RBCS. Effects of other factors such as the stability of RBCL mRNA may come into play.
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MESH Headings
- Cell Death
- Down-Regulation
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Genes, Plant
- Oryza/enzymology
- Oryza/genetics
- Oryza/growth & development
- Plant Leaves/enzymology
- Plant Leaves/genetics
- Plant Leaves/growth & development
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/growth & development
- Plants, Genetically Modified/metabolism
- Polyribosomes/enzymology
- Polyribosomes/genetics
- Polyribosomes/metabolism
- Protein Biosynthesis
- RNA Stability
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Ribulose-Bisphosphate Carboxylase/genetics
- Ribulose-Bisphosphate Carboxylase/metabolism
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Affiliation(s)
- Yuji Suzuki
- Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Sendai, Japan.
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Heinnickel ML, Alric J, Wittkopp T, Yang W, Catalanotti C, Dent R, Niyogi KK, Wollman FA, Grossman AR. Novel thylakoid membrane GreenCut protein CPLD38 impacts accumulation of the cytochrome b6f complex and associated regulatory processes. J Biol Chem 2013; 288:7024-36. [PMID: 23303190 PMCID: PMC3591612 DOI: 10.1074/jbc.m112.427476] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Based on previous comparative genomic analyses, a set of nearly 600 polypeptides was identified that is present in green algae and flowering and nonflowering plants but is not present (or is highly diverged) in nonphotosynthetic organisms. The gene encoding one of these “GreenCut” proteins, CPLD38, is in the same operon as ndhL in most cyanobacteria; the NdhL protein is part of a complex essential for cyanobacterial respiration. A cpld38 mutant of Chlamydomonas reinhardtii does not grow on minimal medium, is high light-sensitive under photoheterotrophic conditions, has lower accumulation of photosynthetic complexes, reduced photosynthetic electron flow to P700+, and reduced photochemical efficiency of photosystem II (ΦPSII); these phenotypes are rescued by a wild-type copy of CPLD38. Single turnover flash experiments and biochemical analyses demonstrated that cytochrome b6f function was severely compromised, and the levels of transcripts and polypeptide subunits of the cytochrome b6f complex were also significantly lower in the cpld38 mutant. Furthermore, subunits of the cytochrome b6f complex in mutant cells turned over much more rapidly than in wild-type cells. Interestingly, PTOX2 and NDA2, two major proteins involved in chlororespiration, were more than 5-fold higher in mutants relative to wild-type cells, suggesting a shift in the cpld38 mutant from photosynthesis toward chlororespiratory metabolism, which is supported by experiments that quantify the reduction state of the plastoquinone pool. Together, these findings support the hypothesis that CPLD38 impacts the stability of the cytochrome b6f complex and possibly plays a role in balancing redox inputs to the quinone pool from photosynthesis and chlororespiration.
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Affiliation(s)
- Mark L Heinnickel
- Department of Plant Biology, Carnegie Institute for Science, Stanford, California 94305, USA.
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Xiao J, Li J, Ouyang M, Yun T, He B, Ji D, Ma J, Chi W, Lu C, Zhang L. DAC is involved in the accumulation of the cytochrome b6/f complex in Arabidopsis. PLANT PHYSIOLOGY 2012; 160:1911-22. [PMID: 23043079 PMCID: PMC3510120 DOI: 10.1104/pp.112.204891] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The biogenesis and assembly of photosynthetic multisubunit protein complexes is assisted by a series of nucleus-encoded auxiliary protein factors. In this study, we characterize the dac mutant of Arabidopsis (Arabidopsis thaliana), which shows a severe defect in the accumulation of the cytochrome b(6)/f complex, and provide evidence suggesting that the efficiency of cytochrome b(6)/f complex assembly is affected in the mutant. DAC is a thylakoid membrane protein with two predicted transmembrane domains that is conserved from cyanobacteria to vascular plants. Yeast (Saccharomyces cerevisiae) two-hybrid and coimmunoprecipitation analyses revealed a specific interaction between DAC and PetD, a subunit of the cytochrome b(6)/f complex. However, DAC was found not to be an intrinsic component of the cytochrome b(6)/f complex. In vivo chloroplast protein labeling experiments showed that the labeling rates of the PetD and cytochrome f proteins were greatly reduced, whereas that of the cytochrome b(6) protein remained normal in the dac mutant. DAC appears to be a novel factor involved in the assembly/stabilization of the cytochrome b(6)/f complex, possibly through interaction with the PetD protein.
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39
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Suzuki Y, Makino A. Availability of Rubisco small subunit up-regulates the transcript levels of large subunit for stoichiometric assembly of its holoenzyme in rice. PLANT PHYSIOLOGY 2012; 160:533-40. [PMID: 22811433 PMCID: PMC3440226 DOI: 10.1104/pp.112.201459] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 07/15/2012] [Indexed: 05/20/2023]
Abstract
Rubisco is composed of eight small subunits coded for by the nuclear RBCS multigene family and eight large subunits coded for by the rbcL gene in the plastome. For synthesis of the Rubisco holoenzyme, both genes need to be expressed coordinately. To investigate this molecular mechanism, the protein synthesis of two subunits of Rubisco was characterized in transgenic rice (Oryza sativa) plants with overexpression or antisense suppression of the RBCS gene. Total RBCS and rbcL messenger RNA (mRNA) levels and RBCS and RbcL synthesis simultaneously increased in RBCS-sense plants, although the increase in total RBCS mRNA level was greater. In RBCS-antisense plants, the levels of these mRNAs and the synthesis of the corresponding proteins declined to a similar extent. The amount of RBCS synthesized was tightly correlated with rbcL mRNA level among genotypes but not associated with changes in mRNA levels of other major chloroplast-encoded photosynthetic genes. The level of rbcL mRNA, in turn, was tightly correlated with the amount of RbcL synthesized, the molar ratio of RBCS synthesis to RbcL synthesis being identical irrespective of genotype. Polysome loading of rbcL mRNA was not changed. These results demonstrate that the availability of RBCS protein up-regulates the gene expression of rbcL primarily at the transcript level in a quantitative manner for stoichiometric assembly of Rubisco holoenzyme.
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MESH Headings
- Cell Culture Techniques/methods
- Chloroplasts/enzymology
- Chloroplasts/genetics
- Enzyme Activation
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Genes, Plant
- Holoenzymes/genetics
- Holoenzymes/metabolism
- Oryza/enzymology
- Oryza/genetics
- Photosynthesis
- Plant Leaves/enzymology
- Plant Leaves/genetics
- Plant Proteins/genetics
- Plants, Genetically Modified/enzymology
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/metabolism
- Polyribosomes/metabolism
- Protein Biosynthesis
- Protein Subunits/genetics
- Protein Subunits/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Plant/analysis
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Ribulose-Bisphosphate Carboxylase/genetics
- Ribulose-Bisphosphate Carboxylase/metabolism
- Transcription, Genetic
- Up-Regulation
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Affiliation(s)
- Yuji Suzuki
- Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan.
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40
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Herrmann JM, Woellhaf MW, Bonnefoy N. Control of protein synthesis in yeast mitochondria: the concept of translational activators. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:286-94. [PMID: 22450032 DOI: 10.1016/j.bbamcr.2012.03.007] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/01/2012] [Accepted: 03/08/2012] [Indexed: 12/18/2022]
Abstract
Mitochondria contain their own genome which codes for a small number of proteins. Most mitochondrial translation products are part of the membrane-embedded reaction centers of the respiratory chain complexes. In the yeast Saccharomyces cerevisiae, the expression of these proteins is regulated by translational activators that bind mitochondrial mRNAs, in most cases to their 5'-untranslated regions, and each mitochondrial mRNA appears to have its own translational activator(s). Recent studies showed that these translational activators can be part of feedback control loops which only permit translation if the downstream assembly of nascent translation products can occur. In several cases, the accumulation of a non-assembled protein prevents further synthesis of this protein but not translation in general. These control loops prevent the synthesis of potentially harmful assembly intermediates of the reaction centers of mitochondrial enzymes. Since such regulatory feedback loops only work if translation occurs in the compartment in which the complexes of the respiratory chain are assembled, these control mechanisms require the presence of a translation machinery in mitochondria. This might explain why eukaryotic cells maintained DNA in mitochondria during the last two billion years of evolution. This review gives an overview of the mitochondrial translation system and summarizes the current knowledge on translational activators and their role in the regulation of mitochondrial protein synthesis. This article is part of a Special Issue entitled: Protein import and quality control in mitochondria and plastids.
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Affiliation(s)
- Johannes M Herrmann
- Cell Biology, Erwin-Schrödinger-Strasse 13, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
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41
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Kallas T. Cytochrome b 6 f Complex at the Heart of Energy Transduction and Redox Signaling. PHOTOSYNTHESIS 2012. [DOI: 10.1007/978-94-007-1579-0_21] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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42
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Abstract
Central in respiration or photosynthesis, the cytochrome bc1 and b6f complexes are regarded as functionally similar quinol oxidoreductases. They both catalyse a redox loop, the Q-cycle, which couples electron and proton transfer. This loop involves a bifurcated electron transfer step considered as being mechanistically mandatory, making the Q-cycle indispensable for growth. Attempts to falsify this paradigm in the case of cytochrome bc1 have failed. The rapid proteolytic degradation of b6f complexes bearing mutations aimed at hindering the Q-cycle has precluded so far the experimental assessment of this model in the photosynthetic chain. Here we combine mutations in Chlamydomonas that inactivate the redox loop but preserve high accumulation levels of b6f complexes. The oxidoreductase activity of these crippled complexes is sufficient to sustain photosynthetic growth, which demonstrates that the Q-cycle is dispensable for oxygenic photosynthesis. The Q-cycle is thought to be an essential energetic component of the photosynthetic electron-transfer chain. Here, Chlamydomonas mutants with an inactive Q-cycle but normal levels of b6f complexes are shown to display photosynthetic growth, demonstrating the dispensability of the Q-cycle in the oxygenic photosynthetic chain.
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Eberhard S, Loiselay C, Drapier D, Bujaldon S, Girard-Bascou J, Kuras R, Choquet Y, Wollman FA. Dual functions of the nucleus-encoded factor TDA1 in trapping and translation activation of atpA transcripts in Chlamydomonas reinhardtii chloroplasts. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 67:1055-66. [PMID: 21623973 DOI: 10.1111/j.1365-313x.2011.04657.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
After endosymbiosis, organelles lost most of their initial genome. Moreover, expression of the few remaining genes became tightly controlled by the nucleus through trans-acting protein factors that are required for post-transcriptional expression (maturation/stability or translation) of a single (or a few) specific organelle target mRNA(s). Here, we characterize the nucleus-encoded TDA1 factor, which is specifically required for translation of the chloroplast atpA transcript that encodes subunit α of ATP synthase in Chlamydomonas reinhardtii. The sequence of TDA1 contains eight copies of a degenerate 38-residue motif, that we named octotrico peptide repeat (OPR), which has been previously described in a few other trans-acting factors targeted to the C. reinhardtii chloroplast. Interestingly, a proportion of the untranslated atpA transcripts are sequestered into high-density, non-polysomic, ribonucleoprotein complexes. Our results suggest that TDA1 has a dual function: (i) trapping a subset of untranslated atpA transcripts into non-polysomic complexes, and (ii) translational activation of these transcripts. We discuss these results in light of our previous observation that only a proportion of atpA transcripts are translated at any given time in the chloroplast of C. reinhardtii.
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Affiliation(s)
- Stephan Eberhard
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Université Pierre et Marie Curie (UPMC - Paris 06), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005 Paris, France.
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Coragliotti AT, Beligni MV, Franklin SE, Mayfield SP. Molecular factors affecting the accumulation of recombinant proteins in the Chlamydomonas reinhardtii chloroplast. Mol Biotechnol 2011; 48:60-75. [PMID: 21113690 PMCID: PMC3068253 DOI: 10.1007/s12033-010-9348-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In an effort to develop microalgae as a robust system for the production of valuable proteins, we analyzed some of the factors affecting recombinant protein expression in the chloroplast of the green alga Chlamydomonas reinhardtii. We monitored mRNA accumulation, protein synthesis, and protein turnover for three codon-optimized transgenes including GFP, bacterial luciferase, and a large single chain antibody. GFP and luciferase proteins were quite stable, while the antibody was less so. Measurements of protein synthesis, in contrast, clearly showed that translation of the three chimeric mRNAs was greatly reduced when compared to endogenous mRNAs under control of the same atpA promoter/UTR. Only in a few conditions this could be explained by limited mRNA availability since, in most cases, recombinant mRNAs accumulated quite well when compared to the atpA mRNA. In vitro toeprint and in vivo polysome analyses suggest that reduced ribosome association might contribute to limited translational efficiency. However, when recombinant polysome levels and protein synthesis are analyzed as a whole, it becomes clear that other steps, such as inefficient protein elongation, are likely to have a considerable impact. Taken together, our results point to translation as the main step limiting the expression of heterologous proteins in the C. reinhardtii chloroplast.
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Affiliation(s)
- Anna T Coragliotti
- The Department of Cell Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N Torrey Pines Rd, La Jolla, CA 92037, USA
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Johnson X. Manipulating RuBisCO accumulation in the green alga, Chlamydomonas reinhardtii. PLANT MOLECULAR BIOLOGY 2011; 76:397-405. [PMID: 21607658 DOI: 10.1007/s11103-011-9783-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 04/27/2011] [Indexed: 05/03/2023]
Abstract
The nuclear factor, Maturation/stability of RbcL (MRL1), regulates the accumulation of the chloroplast rbcL gene transcript in Chlamydomonas reinhardtii by stabilising the mRNA via its 5' UTR. An absence of MRL1 in algal mrl1 mutants leads to a complete absence of RuBisCO large subunit protein and thus a lack of accumulation of the RuBisCO holoenzyme. By complementing mrl1 mutants by random transformation of the nuclear genome with the MRL1 cDNA, different levels of rbcL transcript accumulate. We also observe that RuBisCO Large Subunit accumulation is perturbed. Complemented strains accumulating as little as 15% RuBisCO protein can grow phototrophically while RuBisCO in this range is limiting for phototrophic growth. We also observe that photosynthetic activity, here measured by the quantum yield of PSII, appears to be a determinant for phototrophic growth. In some strains that accumulate less RuBisCO, a strong production of reactive oxygen species is detected. In the absence of RuBisCO, oxygen possibly acts as the PSI terminal electron acceptor. These results show that random transformation of MRL1 into mrl1 mutants can change RuBisCO accumulation allowing a range of phototrophic growth phenotypes. Furthermore, this technique allows for the isolation of strains with low RuBisCO, within the range of acceptable photosynthetic growth and reasonably low ROS production. MRL1 is thus a potential tool for applications to divert electrons away from photosynthetic carbon metabolism towards alternative pathways.
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Affiliation(s)
- Xenie Johnson
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7141/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, 75005 Paris, France.
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Boulouis A, Raynaud C, Bujaldon S, Aznar A, Wollman FA, Choquet Y. The nucleus-encoded trans-acting factor MCA1 plays a critical role in the regulation of cytochrome f synthesis in Chlamydomonas chloroplasts. THE PLANT CELL 2011; 23:333-49. [PMID: 21216944 PMCID: PMC3051260 DOI: 10.1105/tpc.110.078170] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 11/26/2010] [Accepted: 12/07/2010] [Indexed: 05/18/2023]
Abstract
Organelle gene expression is characterized by nucleus-encoded trans-acting factors that control posttranscriptional steps in a gene-specific manner. As a typical example, in Chlamydomonas reinhardtii, expression of the chloroplast petA gene encoding cytochrome f, a major subunit of the cytochrome b(6)f complex, depends on MCA1 and TCA1, required for the accumulation and translation of the petA mRNA. Here, we show that these two proteins associate in high molecular mass complexes that also contain the petA mRNA. We demonstrate that MCA1 is degraded upon interaction with unassembled cytochrome f that transiently accumulates during the biogenesis of the cytochrome b(6)f complex. Strikingly, this interaction relies on the very same residues that form the repressor motif involved in the Control by Epistasy of cytochrome f Synthesis (CES), a negative feedback mechanism that downregulates cytochrome f synthesis when its assembly within the cytochrome b(6)f complex is compromised. Based on these new findings, we present a revised picture for the CES regulation of petA mRNA translation that involves proteolysis of the translation enhancer MCA1, triggered by its interaction with unassembled cytochrome f.
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Affiliation(s)
| | | | | | | | | | - Yves Choquet
- Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, F-75005 Paris, France
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47
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Meinecke L, Alawady A, Schroda M, Willows R, Kobayashi MC, Niyogi KK, Grimm B, Beck CF. Chlorophyll-deficient mutants of Chlamydomonas reinhardtii that accumulate magnesium protoporphyrin IX. PLANT MOLECULAR BIOLOGY 2010; 72:643-58. [PMID: 20127142 PMCID: PMC2837180 DOI: 10.1007/s11103-010-9604-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Accepted: 01/13/2010] [Indexed: 05/12/2023]
Abstract
Two Chlamydomonas reinhardtii mutants defective in CHLM encoding Mg-protoporphyrin IX methyltransferase (MgPMT) were identified. The mutants, one with a missense mutation (chlM-1) and a second mutant with a splicing defect (chlM-2), do not accumulate chlorophyll, are yellow in the dark and dim light, and their growth is inhibited at higher light intensities. They accumulate Mg-protoporphyrin IX (MgProto), the substrate of MgPMT and this may be the cause for their light sensitivity. In the dark, both mutants showed a drastic reduction in the amounts of core proteins of photosystems I and II and light-harvesting chlorophyll a/b-binding proteins. However, LHC mRNAs accumulated above wild-type levels. The accumulation of the transcripts of the LHC and other genes that were expressed at higher levels in the mutants during dark incubation was attenuated in the initial phase of light exposure. No regulatory effects of the constitutively 7- to 18-fold increased MgProto levels on gene expression were detected, supporting previous results in which MgProto and heme in Chlamydomonas were assigned roles as second messengers only in the transient activation of genes by light.
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Affiliation(s)
- Linda Meinecke
- Fakultaet fuer Biologie, Institut fuer Biologie III, Universitaet Freiburg, Schaenzlestrasse 1, 79104 Freiburg, Germany
| | - Ali Alawady
- Institut fuer Biologie/Pflanzenphysiologie, Humboldt Universitaet, Philippstrasse 13, 10115 Berlin, Germany
| | - Michael Schroda
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476 Potsdam-Golm, Germany
| | - Robert Willows
- Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, 2109 Australia
| | - Marilyn C. Kobayashi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102 USA
| | - Krishna K. Niyogi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102 USA
| | - Bernhard Grimm
- Institut fuer Biologie/Pflanzenphysiologie, Humboldt Universitaet, Philippstrasse 13, 10115 Berlin, Germany
| | - Christoph F. Beck
- Fakultaet fuer Biologie, Institut fuer Biologie III, Universitaet Freiburg, Schaenzlestrasse 1, 79104 Freiburg, Germany
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48
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Johnson X, Wostrikoff K, Finazzi G, Kuras R, Schwarz C, Bujaldon S, Nickelsen J, Stern DB, Wollman FA, Vallon O. MRL1, a conserved Pentatricopeptide repeat protein, is required for stabilization of rbcL mRNA in Chlamydomonas and Arabidopsis. THE PLANT CELL 2010; 22:234-48. [PMID: 20097872 PMCID: PMC2828700 DOI: 10.1105/tpc.109.066266] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 12/14/2009] [Accepted: 01/12/2010] [Indexed: 05/18/2023]
Abstract
We identify and functionally characterize MRL1, a conserved nuclear-encoded regulator of the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase. The nonphotosynthetic mrl1 mutant of Chlamydomonas reinhardtii lacks ribulose-1,5-bisphosphate carboxylase/oxygenase, and the resulting block in electron transfer is partially compensated by redirecting electrons toward molecular oxygen via the Mehler reaction. This allows continued electron flow and constitutive nonphotochemical quenching, enhancing cell survival during illumination in spite of photosystem II and photosystem I photoinhibition. The mrl1 mutant transcribes rbcL normally, but the mRNA is unstable. The molecular target of MRL1 is the 5 ' untranslated region of rbcL. MRL1 is located in the chloroplast stroma, in a high molecular mass complex. Treatment with RNase or deletion of the rbcL gene induces a shift of the complex toward lower molecular mass fractions. MRL1 is well conserved throughout the green lineage, much more so than the 10 other pentatricopeptide repeat proteins found in Chlamydomonas. Depending upon the organism, MRL1 contains 11 to 14 pentatricopeptide repeats followed by a novel MRL1-C domain. In Arabidopsis thaliana, MRL1 also acts on rbcL and is necessary for the production/stabilization of the processed transcript, presumably because it acts as a barrier to 5 ' >3 ' degradation. The Arabidopsis mrl1 mutant retains normal levels of the primary transcript and full photosynthetic capacity.
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Affiliation(s)
- Xenie Johnson
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7141/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, Paris 75005, France
| | - Katia Wostrikoff
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, New York 14853
| | - Giovanni Finazzi
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7141/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, Paris 75005, France
| | - Richard Kuras
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7141/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, Paris 75005, France
| | - Christian Schwarz
- Biozentrum Ludwig-Maximilian Universität München, D-82152 Planegg-Martinsried, Germany
| | - Sandrine Bujaldon
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7141/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, Paris 75005, France
| | - Joerg Nickelsen
- Biozentrum Ludwig-Maximilian Universität München, D-82152 Planegg-Martinsried, Germany
| | - David B. Stern
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, New York 14853
| | - Francis-André Wollman
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7141/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, Paris 75005, France
| | - Olivier Vallon
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7141/Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, Paris 75005, France
- Address correspondence to
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Tsunoyama Y, Bernát G, Dyczmons NG, Schneider D, Rögner M. Multiple Rieske proteins enable short- and long-term light adaptation of Synechocystis sp. PCC 6803. J Biol Chem 2009; 284:27875-27883. [PMID: 19674969 PMCID: PMC2788838 DOI: 10.1074/jbc.m109.011189] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 08/12/2009] [Indexed: 11/06/2022] Open
Abstract
In contrast to eukaryotes, most cyanobacteria contain several isoforms of the Rieske iron-sulfur protein, PetC, resulting in heterogeneity in the composition of the cytochrome b(6)f complexes. Of three isoforms in the mesophilic cyanobacterium Synechocystis PCC 6803, PetC1 is the major Rieske protein in the cytochrome b(6)f complex, whereas the physiological function of PetC2 and PetC3 is still uncertain. Comparison of wild type and various petC-deficient strains under selected light conditions revealed distinct functional differences: high-light exposure of wild type cells resulted in a significantly enhanced petC2 transcript level, whereas a Delta petC1 mutant showed a low cytochrome b(6)f content, low electron flux, and a considerably increased accumulation of cytochrome-bd oxidase. In contrast to wild type and Delta petC1, Delta petC2 and Delta petC3 strains still grew fast under high-light conditions although all three Rieske proteins are required for maximal electron transport rates. Although the presence of PetC3 appears to be required for activation of the cyclic electron transport, state transitions were more effective in the absence of PetC2 and/or PetC3. In summary, our data suggest defined roles of the various PetC proteins in short- and long-term light adaptation.
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Affiliation(s)
- Yuichi Tsunoyama
- Department of Plant Biochemistry, Ruhr-University Bochum, 44780 Bochum, Germany; Division of Biology, Radioisotope Research Center, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Gábor Bernát
- Department of Plant Biochemistry, Ruhr-University Bochum, 44780 Bochum, Germany
| | - Nina G Dyczmons
- Department of Plant Biochemistry, Ruhr-University Bochum, 44780 Bochum, Germany
| | - Dirk Schneider
- Department of Biochemistry and Molecular Biology, ZBMZ, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Matthias Rögner
- Department of Plant Biochemistry, Ruhr-University Bochum, 44780 Bochum, Germany.
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50
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Johnson X, Vandystadt G, Bujaldon S, Wollman FA, Dubois R, Roussel P, Alric J, Béal D. A new setup for in vivo fluorescence imaging of photosynthetic activity. PHOTOSYNTHESIS RESEARCH 2009; 102:85-93. [PMID: 19697150 DOI: 10.1007/s11120-009-9487-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 08/03/2009] [Indexed: 05/22/2023]
Abstract
Here, we describe a new imaging setup able to assess in vivo photosynthetic activity. The system specifically measures time-resolved chlorophyll fluorescence in response to light. It is composed of a fast digital camera equipped with a wide-angle lens for the analysis of samples up to 10 x 10 cm, i.e. entire plants or petri dishes. In the choice of CCD, we have opted for a 12-bits high frame rate [150 fps (frames per second)] at the expense of definition (640 x 480 pixels). Although the choice of digital camera is always a compromise between these two related features, we have designed a flexible system allowing the fast sampling of images (down to 100 micros) with a maximum spatial resolution. This image readout system, synchronized with actinic light and saturating pulses, allows a precise determination of F(0) and F(M), which is required to monitor PSII activity. This new imaging system, together with image processing techniques, is useful to investigate the heterogeneity of photosynthetic activity within leaves or to screen large numbers of unicellular algal mutant colonies to identify those with subtle changes in photosynthetic electron flow.
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Affiliation(s)
- Xenie Johnson
- Institut de Biologie Physico-Chimique, UMR 7141, CNRS et Université Pierre et Marie Curie (Paris VI), Paris, France
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