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Yan S, Li J, Zhang Q, Jia S, Zhang Q, Wang R, Ju M, Gu P. Transcriptional Response of Wolfberry to Infestation with the Endophytic Fusarium nematophilum Strain NQ8GII4. PLANT DISEASE 2024; 108:1514-1525. [PMID: 38050402 DOI: 10.1094/pdis-07-23-1397-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
Fusarium nematophilum NQ8GII4 is an endophytic fungus isolated from the root of healthy wolfberry (Lycium barbarum). Previous studies have reported that NQ8GII4 could dwell in wolfberry roots and enhance the defense responses in wolfberry against root rot, which is caused by F. oxysporum. To further elucidate the molecular mechanism of wolfberry disease resistance induced by NQ8GII4, in the present study, we adopted RNA sequencing analysis to profile the transcriptome of wolfberry response to NQ8GII4 infestation over a time course of 3 and 7 days postinoculation. Gene ontology enrichment analysis revealed that differentially expressed genes (DEGs) were enriched in biological regulation, response to stimulus, signaling, detoxification, immune system process, transporter activity, electron carrier activity, transcription factor activity, nucleic acid binding transcription factor, and antioxidant activity. Through Kyoto Encyclopedia of Genes and Genomes analysis, it was found that many of these DEGs were enriched in pathways related to plant-pathogen interactions, hormone signal transduction, and the phenylpropanoid biosynthesis pathway in wolfberry. This result suggested that innate immunity, phytohormone signaling, and numerous phenylpropanoid compounds comprise a complex defense network in wolfberry. Chloroplast 50S ribosomal proteins were consistently located at the core position of the response in wolfberry following infestation with NQ8GII4 analyzed by the protein-protein interaction network. This study elucidated the molecular mechanism underlying the interaction between NQ8GII4 and wolfberry, clarified the wolfberry immune response network to endophytic fungi infestation, identified candidate resistance genes in wolfberry, and provided a fundamental date for subsequent work.
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Affiliation(s)
- Siyuan Yan
- College of Forestry and Prataculture, Ningxia University, Yinchuan 750021, China
| | - Jin Li
- School of Agriculture, Ningxia University, Yinchuan 750021, China
| | - Qingchen Zhang
- Department of Pharmacotherapy and Translational Research, University of Florida, Gainesville, FL 32611, U.S.A
| | - Shuxin Jia
- School of Agriculture, Ningxia University, Yinchuan 750021, China
| | - Qiangqiang Zhang
- College of Forestry and Prataculture, Ningxia University, Yinchuan 750021, China
| | - Ruotong Wang
- School of Agriculture, Ningxia University, Yinchuan 750021, China
| | - Mingxiu Ju
- College of Forestry and Prataculture, Ningxia University, Yinchuan 750021, China
| | - Peiwen Gu
- College of Forestry and Prataculture, Ningxia University, Yinchuan 750021, China
- School of Agriculture, Ningxia University, Yinchuan 750021, China
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2
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Luo P, Shi C, Zhou Y, Zhou J, Zhang X, Wang Y, Yang Y, Peng X, Xie T, Tang X. The nuclear-localized RNA helicase 13 is essential for chloroplast development in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5057-5071. [PMID: 37310806 DOI: 10.1093/jxb/erad225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/12/2023] [Indexed: 06/15/2023]
Abstract
The chloroplast is a semi-autonomous organelle with a double membrane structure, and its structural stability is a prerequisite for its correct function. Chloroplast development is regulated by known nuclear-encoded chloroplast proteins or proteins encoded within the chloroplast itself. However, the mechanism of chloroplast development regulated by other organelles remains largely unknown. Here, we report that the nuclear-localized DEAD-box RNA helicase 13 (RH13) is essential for chloroplast development in Arabidopsis thaliana. RH13 is widely expressed in tissues and localized to the nucleolus. A homozygous rh13 mutant shows abnormal chloroplast structure and leaf morphogenesis. Proteomic analysis showed that the expression levels of photosynthesis-related proteins in chloroplasts were reduced due to loss of RH13. Furthermore, RNA-sequencing and proteomics data revealed decreases in the expression levels of these chloroplast-related genes, which undergo alternative splicing events in the rh13 mutant. Taken together, we propose that nucleolus-localized RH13 is critical for chloroplast development in Arabidopsis.
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Affiliation(s)
- Pan Luo
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Science, Hubei University, Wuhan 430062, China
| | - Ce Shi
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yi Zhou
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Science, Hubei University, Wuhan 430062, China
| | - Jiao Zhou
- State Key Laboratory of Virology, Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xuecheng Zhang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yukun Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yong Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Science, Hubei University, Wuhan 430062, China
| | - Xiongbo Peng
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Tingting Xie
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Xingchun Tang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Science, Hubei University, Wuhan 430062, China
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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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4
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Sandoval-Ibáñez O, Rolo D, Ghandour R, Hertle AP, Armarego-Marriott T, Sampathkumar A, Zoschke R, Bock R. De-etiolation-induced protein 1 (DEIP1) mediates assembly of the cytochrome b 6f complex in Arabidopsis. Nat Commun 2022; 13:4045. [PMID: 35831297 PMCID: PMC9279372 DOI: 10.1038/s41467-022-31758-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 07/01/2022] [Indexed: 11/26/2022] Open
Abstract
The conversion of light energy to chemical energy by photosynthesis requires the concerted action of large protein complexes in the thylakoid membrane. Recent work has provided fundamental insights into the three-dimensional structure of these complexes, but how they are assembled from hundreds of parts remains poorly understood. Particularly little is known about the biogenesis of the cytochrome b6f complex (Cytb6f), the redox-coupling complex that interconnects the two photosystems. Here we report the identification of a factor that guides the assembly of Cytb6f in thylakoids of chloroplasts. The protein, DE-ETIOLATION-INDUCED PROTEIN 1 (DEIP1), resides in the thylakoid membrane and is essential for photoautotrophic growth. Knock-out mutants show a specific loss of Cytb6f, and are defective in complex assembly. We demonstrate that DEIP1 interacts with the two cytochrome subunits of the complex, PetA and PetB, and mediates the assembly of intermediates in Cytb6f biogenesis. The identification of DEIP1 provides an entry point into the study of the assembly pathway of a crucial complex in photosynthetic electron transfer. The Cytb6f complex is a multi-subunit enzyme that couples the two photosystems during the light reactions of photosynthesis. Here the authors show that the thylakoid-localized DEIP1 protein interacts with the PetA and PetB subunits, and is essential for Cytb6f complex assembly in Arabidopsis.
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Affiliation(s)
- Omar Sandoval-Ibáñez
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - David Rolo
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Rabea Ghandour
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Alexander P Hertle
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Tegan Armarego-Marriott
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Arun Sampathkumar
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Ralph Bock
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
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Grossman A, Sanz-Luque E, Yi H, Yang W. Building the GreenCut2 suite of proteins to unmask photosynthetic function and regulation. Microbiology (Reading) 2019; 165:697-718. [DOI: 10.1099/mic.0.000788] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Arthur Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Emanuel Sanz-Luque
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Heng Yi
- Key Laboratory of Photobiology, Institute of Botany (CAS), Beijing, PR China
- University of Chinese Academy of Sciences, Beijing, PR China
| | - Wenqiang Yang
- Key Laboratory of Photobiology, Institute of Botany (CAS), Beijing, PR China
- University of Chinese Academy of Sciences, Beijing, PR China
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Hartings S, Paradies S, Karnuth B, Eisfeld S, Mehsing J, Wolff C, Levey T, Westhoff P, Meierhoff K. The DnaJ-Like Zinc-Finger Protein HCF222 Is Required for Thylakoid Membrane Biogenesis in Plants. PLANT PHYSIOLOGY 2017; 174:1807-1824. [PMID: 28572458 PMCID: PMC5490910 DOI: 10.1104/pp.17.00401] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/31/2017] [Indexed: 05/22/2023]
Abstract
To understand the biogenesis of the thylakoid membrane in higher plants and to identify auxiliary proteins required to build up this highly complex membrane system, we have characterized the allelic nuclear mutants high chlorophyll fluorescence222-1 (hcf222-1) and hcf222-2 and isolated the causal gene by map-based cloning. In the ethyl methanesulfonate-induced mutant hcf222-1, the accumulation of the cytochrome b6f (Cytb6f) complex was reduced to 30% compared with the wild type. Other thylakoid membrane complexes accumulated to normal levels. The T-DNA knockout mutant hcf222-2 showed a more severe defect with respect to thylakoid membrane proteins and accumulated only 10% of the Cytb6f complex, accompanied by a reduction in photosystem II, the photosystem II light-harvesting complex, and photosystem I. HCF222 encodes a protein of 99 amino acids in Arabidopsis (Arabidopsis thaliana) that has similarities to the cysteine-rich zinc-binding domain of DnaJ chaperones. The insulin precipitation assay demonstrated that HCF222 has disulfide reductase activity in vitro. The protein is conserved in higher plants and bryophytes but absent in algae and cyanobacteria. Confocal fluorescence microscopy showed that a fraction of HCF222-green fluorescent protein was detectable in the endoplasmic reticulum but that it also could be recognized in chloroplasts. A fusion construct of HCF222 containing a plastid transit peptide targets the protein into chloroplasts and was able to complement the mutational defect. These findings indicate that the chloroplast-targeted HCF222 is indispensable for the maturation and/or assembly of the Cytb6f complex and is very likely involved in thiol-disulfide biochemistry at the thylakoid membrane.
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Affiliation(s)
- Stephanie Hartings
- Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, 40225 Duesseldorf, Germany
| | - Susanne Paradies
- Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, 40225 Duesseldorf, Germany
| | - Bianca Karnuth
- Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, 40225 Duesseldorf, Germany
| | - Sabrina Eisfeld
- Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, 40225 Duesseldorf, Germany
| | - Jasmin Mehsing
- Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, 40225 Duesseldorf, Germany
| | - Christian Wolff
- Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, 40225 Duesseldorf, Germany
| | - Tatjana Levey
- Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, 40225 Duesseldorf, Germany
| | - Peter Westhoff
- Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, 40225 Duesseldorf, Germany
| | - Karin Meierhoff
- Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, 40225 Duesseldorf, Germany
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7
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Wagner R, von Sydow L, Aigner H, Netotea S, Brugière S, Sjögren L, Ferro M, Clarke A, Funk C. Deletion of FtsH11 protease has impact on chloroplast structure and function in Arabidopsis thaliana when grown under continuous light. PLANT, CELL & ENVIRONMENT 2016; 39:2530-2544. [PMID: 27479913 DOI: 10.1111/pce.12808] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 07/12/2016] [Accepted: 07/17/2016] [Indexed: 05/20/2023]
Abstract
The membrane-integrated metalloprotease FtsH11 of Arabidopsis thaliana is proposed to be dual-targeted to mitochondria and chloroplasts. A bleached phenotype was observed in ftsh11 grown at long days or continuous light, pointing to disturbances in the chloroplast. Within the chloroplast, FtsH11 was found to be located exclusively in the envelope. Two chloroplast-located proteins of unknown function (Tic22-like protein and YGGT-A) showed significantly higher abundance in envelope membranes and intact chloroplasts of ftsh11 and therefore qualify as potential substrates for the FtsH11 protease. No proteomic changes were observed in the mitochondria of 6-week-old ftsh11 compared with wild type, and FtsH11 was not immunodetected in these organelles. The abundance of plastidic proteins, especially of photosynthetic proteins, was altered even during standard growth conditions in total leaves of ftsh11. At continuous light, the amount of photosystem I decreased relative to photosystem II, accompanied by a drastic change of the chloroplast morphology and a drop of non-photochemical quenching. FtsH11 is crucial for chloroplast structure and function during growth in prolonged photoperiod.
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Affiliation(s)
- Raik Wagner
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
| | - Lotta von Sydow
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
| | - Harald Aigner
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
| | - Sergiu Netotea
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
- Bioinformatics Infrastructure for Life Sciences (BILS), Linköping, Sweden
| | - Sabine Brugière
- U1038 INSERM/CEA/UJ, Institut de Recherches en Technologies et Sciences pour le Vivant, Grenoble, Cedex 9, France
| | - Lars Sjögren
- Department of Biological and Environmental Sciences, Gothenburg University, 40530, Gothenburg, Sweden
| | - Myriam Ferro
- U1038 INSERM/CEA/UJ, Institut de Recherches en Technologies et Sciences pour le Vivant, Grenoble, Cedex 9, France
| | - Adrian Clarke
- Department of Biological and Environmental Sciences, Gothenburg University, 40530, Gothenburg, Sweden
| | - Christiane Funk
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden.
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8
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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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9
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Belcher S, Williams-Carrier R, Stiffler N, Barkan A. Large-scale genetic analysis of chloroplast biogenesis in maize. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1004-16. [PMID: 25725436 DOI: 10.1016/j.bbabio.2015.02.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 02/16/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND Chloroplast biogenesis involves a collaboration between several thousand nuclear genes and ~100 genes in the chloroplast. Many of the nuclear genes are of cyanobacterial ancestry and continue to perform their ancestral function. However, many others evolved subsequently and comprise a diverse set of proteins found specifically in photosynthetic eucaryotes. Genetic approaches have been key to the discovery of nuclear genes that participate in chloroplast biogenesis, especially those lacking close homologs outside the plant kingdom. SCOPE OF REVIEW This article summarizes contributions from a genetic resource in maize, the Photosynthetic Mutant Library (PML). The PML collection consists of ~2000 non-photosynthetic mutants induced by Mu transposons. We include a summary of mutant phenotypes for 20 previously unstudied maize genes, including genes encoding chloroplast ribosomal proteins, a PPR protein, tRNA synthetases, proteins involved in plastid transcription, a putative ribosome assembly factor, a chaperonin 60 isoform, and a NifU-domain protein required for Photosystem I biogenesis. MAJOR CONCLUSIONS Insertions in 94 maize genes have been linked thus far to visible and molecular phenotypes with the PML collection. The spectrum of chloroplast biogenesis genes that have been genetically characterized in maize is discussed in the context of related efforts in other organisms. This comparison shows how distinct organismal attributes facilitate the discovery of different gene classes, and reveals examples of functional divergence between monocot and dicot plants. GENERAL SIGNIFICANCE These findings elucidate the biology of an organelle whose activities are fundamental to agriculture and the biosphere. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
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Affiliation(s)
- Susan Belcher
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | | | - Nicholas Stiffler
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
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10
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Allorent G, Osorio S, Vu JL, Falconet D, Jouhet J, Kuntz M, Fernie AR, Lerbs-Mache S, Macherel D, Courtois F, Finazzi G. Adjustments of embryonic photosynthetic activity modulate seed fitness in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2015; 205:707-19. [PMID: 25256557 DOI: 10.1111/nph.13044] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/10/2014] [Indexed: 05/19/2023]
Abstract
In this work, we dissect the physiological role of the transient photosynthetic stage observed in developing seeds of Arabidopsis thaliana. By combining biochemical and biophysical approaches, we demonstrate that despite similar features of the photosynthetic apparatus, light absorption, chloroplast morphology and electron transport are modified in green developing seeds, as a possible response to the peculiar light environment experienced by them as a result of sunlight filtration by the pericarp. In particular, enhanced exposure to far-red light, which mainly excites photosystem I, largely enhances cyclic electron flow around this complex at the expenses of oxygen evolution. Using pharmacological, genetic and metabolic analyses, we show that both linear and cyclic electron flows are important during seed formation for proper germination timing. Linear flow provides specific metabolites related to oxygen and water stress responses. Cyclic electron flow possibly adjusts the ATP to NADPH ratio to cope with the specific energy demand of developing seeds. By providing a comprehensive scenario of the characteristics, function and consequences of embryonic photosynthesis on seed vigour, our data provide a rationale for the transient building up of a photosynthetic machinery in seeds.
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Affiliation(s)
- Guillaume Allorent
- Laboratoire de Physiologie Cellulaire & Végétale, Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique, F-38054, Grenoble, France; Université Grenoble-Alpes, F-38054, Grenoble, France; Commissariat à l'Energie Atomique et Energies Alternatives, Institut de Recherches en Technologies et Sciences pour le Vivant, F-38054, Grenoble, France; Unité Sous Contrat 1359, Institut National Recherche Agronomique, F-38054, Grenoble, France
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11
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Fristedt R, Williams-Carrier R, Merchant SS, Barkan A. A thylakoid membrane protein harboring a DnaJ-type zinc finger domain is required for photosystem I accumulation in plants. J Biol Chem 2014; 289:30657-30667. [PMID: 25228689 DOI: 10.1074/jbc.m114.587758] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Photosystem I (PSI) is a large pigment-protein complex and one of the two photosystems that drive electron transfer in oxygenic photosynthesis. We identified a nuclear gene required specifically for the accumulation of PSI in a forward genetic analysis of chloroplast biogenesis in maize. This gene, designated psa2, belongs to the "GreenCut" gene set, a group of genes found in green algae and plants but not in non-photosynthetic organisms. Disruption of the psa2 ortholog in Arabidopsis likewise resulted in the specific loss of PSI proteins. PSA2 harbors a conserved domain found in DnaJ chaperones where it has been shown to form a zinc finger and to have protein-disulfide isomerase activity. Accordingly, PSA2 exhibited protein-disulfide reductase activity in vitro. PSA2 localized to the thylakoid lumen and was found in a ∼250-kDa complex harboring the peripheral PSI protein PsaG but lacking several core PSI subunits. PSA2 mRNA is coexpressed with mRNAs encoding various proteins involved in the biogenesis of the photosynthetic apparatus with peak expression preceding that of genes encoding structural components. PSA2 protein abundance was not decreased in the absence of PSI but was reduced in the absence of the PSI assembly factor Ycf3. These findings suggest that a complex harboring PSA2 and PsaG mediates thiol transactions in the thylakoid lumen that are important for the assembly of PSI.
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Affiliation(s)
- Rikard Fristedt
- Department of Chemistry and Biochemistry and UCLA, Los Angeles, California 90095; Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095 and
| | | | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry and UCLA, Los Angeles, California 90095; Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095 and
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403.
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12
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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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Abstract
In this review, we consider a selection of recent advances in chloroplast biology. These include new findings concerning chloroplast evolution, such as the identification of Chlamydiae as a third partner in primary endosymbiosis, a second instance of primary endosymbiosis represented by the chromatophores found in amoebae of the genus Paulinella, and a new explanation for the longevity of captured chloroplasts (kleptoplasts) in sacoglossan sea slugs. The controversy surrounding the three-dimensional structure of grana, its recent resolution by tomographic analyses, and the role of the CURVATURE THYLAKOID1 (CURT1) proteins in supporting grana formation are also discussed. We also present an updated inventory of photosynthetic proteins and the factors involved in the assembly of thylakoid multiprotein complexes, and evaluate findings that reveal that cyclic electron flow involves NADPH dehydrogenase (NDH)- and PGRL1/PGR5-dependent pathways, both of which receive electrons from ferredoxin. Other topics covered in this review include new protein components of nucleoids, an updated inventory of the chloroplast proteome, new enzymes in chlorophyll biosynthesis and new candidate messengers in retrograde signaling. Finally, we discuss the first successful synthetic biology approaches that resulted in chloroplasts in which electrons from the photosynthetic light reactions are fed to enzymes derived from secondary metabolism.
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Affiliation(s)
- Poul Erik Jensen
- Copenhagen Plant Science Center (CPSC), Department of Plant and Environmental Sciences, University of CopenhagenThorvaldsensvej 40, DK-1871 Frederiksberg CDenmark
| | - Dario Leister
- Copenhagen Plant Science Center (CPSC), Department of Plant and Environmental Sciences, University of CopenhagenThorvaldsensvej 40, DK-1871 Frederiksberg CDenmark
- Plant Molecular Biology, Department of Biology I, Ludwig-Maximilians-University MunichGroßhaderner Str. 2, D-82152 Planegg-MartinsriedGermany
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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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Jin M, Jiang Y, Sun L, Yin J, Fu H, Wu G, Gao H. Unique organizational and functional features of the cytochrome c maturation system in Shewanella oneidensis. PLoS One 2013; 8:e75610. [PMID: 24040415 PMCID: PMC3769277 DOI: 10.1371/journal.pone.0075610] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 08/16/2013] [Indexed: 11/19/2022] Open
Abstract
Shewanella are renowned for their ability to respire on a wide range of electron acceptors, which has been partially accredited to the presence of a large number of the c-type cytochromes. In the model species S. oneidensis MR-1, at least 41 genes encode c-type cytochromes that are predicted to be intact, thereby likely functional. Previously, in-frame deletion mutants for 36 of these genes were obtained and characterized. In this study, first we completed the construction of an entire set of c-type cytochrome mutants utilizing a newly developed att-based mutagenesis approach, which is more effective and efficient than the approach used previously by circumventing the conventional cloning. Second, we investigated the cytochrome c maturation (Ccm) system in S. oneidensis. There are two loci predicted to encode components of the Ccm system, SO0259-SO0269 and SO0476-SO0478. The former is proven essential for cytochrome c maturation whereas the latter is dispensable. Unlike the single operon organization observed in other γ-proteobacteria, genes at the SO0259-SO0269 locus are uniquely organized into four operons, ccmABCDE, scyA, SO0265, and ccmFGH-SO0269. Functional analysis revealed that the SO0265 gene rather than the scyA and SO0269 genes are relevant to cytochrome c maturation.
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Affiliation(s)
- Miao Jin
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yaoming Jiang
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Linlin Sun
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianhua Yin
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Huihui Fu
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Genfu Wu
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Haichun Gao
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
- * E-mail:
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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: 37] [Impact Index Per Article: 3.4] [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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17
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Lyska D, Meierhoff K, Westhoff P. How to build functional thylakoid membranes: from plastid transcription to protein complex assembly. PLANTA 2013; 237:413-28. [PMID: 22976450 PMCID: PMC3555230 DOI: 10.1007/s00425-012-1752-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 08/10/2012] [Indexed: 05/06/2023]
Abstract
Chloroplasts are the endosymbiotic descendants of cyanobacterium-like prokaryotes. Present genomes of plant and green algae chloroplasts (plastomes) contain ~100 genes mainly encoding for their transcription-/translation-machinery, subunits of the thylakoid membrane complexes (photosystems II and I, cytochrome b (6) f, ATP synthase), and the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase. Nevertheless, proteomic studies have identified several thousand proteins in chloroplasts indicating that the majority of the plastid proteome is not encoded by the plastome. Indeed, plastid and host cell genomes have been massively rearranged in the course of their co-evolution, mainly through gene loss, horizontal gene transfer from the cyanobacterium/chloroplast to the nucleus of the host cell, and the emergence of new nuclear genes. Besides structural components of thylakoid membrane complexes and other (enzymatic) complexes, the nucleus provides essential factors that are involved in a variety of processes inside the chloroplast, like gene expression (transcription, RNA-maturation and translation), complex assembly, and protein import. Here, we provide an overview on regulatory factors that have been described and characterized in the past years, putting emphasis on mechanisms regulating the expression and assembly of the photosynthetic thylakoid membrane complexes.
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Affiliation(s)
- Dagmar Lyska
- Entwicklungs- und Molekularbiologie der Pflanzen, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, Düsseldorf, Germany.
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18
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Lyska D, Engelmann K, Meierhoff K, Westhoff P. pAUL: a gateway-based vector system for adaptive expression and flexible tagging of proteins in Arabidopsis. PLoS One 2013; 8:e53787. [PMID: 23326506 PMCID: PMC3542268 DOI: 10.1371/journal.pone.0053787] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 12/05/2012] [Indexed: 11/18/2022] Open
Abstract
Determination of protein function requires tools that allow its detection and/or purification. As generation of specific antibodies often is laborious and insufficient, protein tagging using epitopes that are recognized by commercially available antibodies and matrices appears more promising. Also, proper spatial and temporal expression of tagged proteins is required to prevent falsification of results. We developed a new series of binary Gateway cloning vectors named pAUL1-20 for C- and N-terminal in-frame fusion of proteins to four different tags: a single (i) HA epitope and (ii) Strep-tagIII, (iii) both epitopes combined to a double tag, and (iv) a triple tag consisting of the double tag extended by a Protein A tag possessing a 3C protease cleavage site. Expression can be driven by either the 35 S CaMV promoter or, for C-terminal fusions, promoters from genes encoding the chloroplast biogenesis factors HCF107, HCF136, or HCF173. Fusions of the four promoters to the GUS gene showed that endogenous promoter sequences are functional and drive expression more moderately and consistently throughout different transgenic lines when compared to the 35 S CaMV promoter. By testing complementation of mutations affected in chloroplast biogenesis factors HCF107 and HCF208, we found that the effect of different promoters and tags on protein function strongly depends on the protein itself. Single-step and tandem affinity purification of HCF208 via different tags confirmed the integrity of the cloned tags.
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Affiliation(s)
- Dagmar Lyska
- Entwicklungs- und Molekularbiologie der Pflanzen, Heinrich-Heine-Universitaet, Duesseldorf, Germany.
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20
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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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21
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Majeran W, Friso G, Asakura Y, Qu X, Huang M, Ponnala L, Watkins KP, Barkan A, van Wijk KJ. Nucleoid-enriched proteomes in developing plastids and chloroplasts from maize leaves: a new conceptual framework for nucleoid functions. PLANT PHYSIOLOGY 2012; 158:156-89. [PMID: 22065420 PMCID: PMC3252073 DOI: 10.1104/pp.111.188474] [Citation(s) in RCA: 182] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 11/06/2011] [Indexed: 05/18/2023]
Abstract
Plastids contain multiple copies of the plastid chromosome, folded together with proteins and RNA into nucleoids. The degree to which components of the plastid gene expression and protein biogenesis machineries are nucleoid associated, and the factors involved in plastid DNA organization, repair, and replication, are poorly understood. To provide a conceptual framework for nucleoid function, we characterized the proteomes of highly enriched nucleoid fractions of proplastids and mature chloroplasts isolated from the maize (Zea mays) leaf base and tip, respectively, using mass spectrometry. Quantitative comparisons with proteomes of unfractionated proplastids and chloroplasts facilitated the determination of nucleoid-enriched proteins. This nucleoid-enriched proteome included proteins involved in DNA replication, organization, and repair as well as transcription, mRNA processing, splicing, and editing. Many proteins of unknown function, including pentatricopeptide repeat (PPR), tetratricopeptide repeat (TPR), DnaJ, and mitochondrial transcription factor (mTERF) domain proteins, were identified. Strikingly, 70S ribosome and ribosome assembly factors were strongly overrepresented in nucleoid fractions, but protein chaperones were not. Our analysis strongly suggests that mRNA processing, splicing, and editing, as well as ribosome assembly, take place in association with the nucleoid, suggesting that these processes occur cotranscriptionally. The plastid developmental state did not dramatically change the nucleoid-enriched proteome but did quantitatively shift the predominating function from RNA metabolism in undeveloped plastids to translation and homeostasis in chloroplasts. This study extends the known maize plastid proteome by hundreds of proteins, including more than 40 PPR and mTERF domain proteins, and provides a resource for targeted studies on plastid gene expression. Details of protein identification and annotation are provided in the Plant Proteome Database.
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22
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de Vitry C. Cytochrome c maturation system on the negative side of bioenergetic membranes: CCB or System IV. FEBS J 2011; 278:4189-97. [DOI: 10.1111/j.1742-4658.2011.08373.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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A novel component of the disulfide-reducing pathway required for cytochrome c assembly in plastids. Genetics 2011; 187:793-802. [PMID: 21220358 DOI: 10.1534/genetics.110.125369] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In plastids, the conversion of energy in the form of light to ATP requires key electron shuttles, the c-type cytochromes, which are defined by the covalent attachment of heme to a CXXCH motif. Plastid c-type cytochrome biogenesis occurs in the thylakoid lumen and requires a system for transmembrane transfer of reductants. Previously, CCDA and CCS5/HCF164, found in all plastid-containing organisms, have been proposed as two components of the disulfide-reducing pathway. In this work, we identify a small novel protein, CCS4, as a third component in this pathway. CCS4 was genetically identified in the green alga Chlamydomonas reinhardtii on the basis of the rescue of the ccs4 mutant, which is blocked in the synthesis of holoforms of plastid c-type cytochromes, namely cytochromes f and c(6). Although CCS4 does not display sequence motifs suggestive of redox or heme-binding function, biochemical and genetic complementation experiments suggest a role in the disulfide-reducing pathway required for heme attachment to apoforms of cytochromes c. Exogenous thiols partially rescue the growth phenotype of the ccs4 mutant concomitant with recovery of holocytochrome f accumulation, as does expression of an ectopic copy of the CCDA gene, encoding a trans-thylakoid transporter of reducing equivalents. We suggest that CCS4 might function to stabilize CCDA or regulate its activity.
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Grossman AR, Karpowicz SJ, Heinnickel M, Dewez D, Hamel B, Dent R, Niyogi KK, Johnson X, Alric J, Wollman FA, Li H, Merchant SS. Phylogenomic analysis of the Chlamydomonas genome unmasks proteins potentially involved in photosynthetic function and regulation. PHOTOSYNTHESIS RESEARCH 2010; 106:3-17. [PMID: 20490922 PMCID: PMC2947710 DOI: 10.1007/s11120-010-9555-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 04/16/2010] [Indexed: 05/18/2023]
Abstract
Chlamydomonas reinhardtii, a unicellular green alga, has been exploited as a reference organism for identifying proteins and activities associated with the photosynthetic apparatus and the functioning of chloroplasts. Recently, the full genome sequence of Chlamydomonas was generated and a set of gene models, representing all genes on the genome, was developed. Using these gene models, and gene models developed for the genomes of other organisms, a phylogenomic, comparative analysis was performed to identify proteins encoded on the Chlamydomonas genome which were likely involved in chloroplast functions (or specifically associated with the green algal lineage); this set of proteins has been designated the GreenCut. Further analyses of those GreenCut proteins with uncharacterized functions and the generation of mutant strains aberrant for these proteins are beginning to unmask new layers of functionality/regulation that are integrated into the workings of the photosynthetic apparatus.
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Affiliation(s)
- Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305, USA.
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Kabeya Y, Nakanishi H, Suzuki K, Ichikawa T, Kondou Y, Matsui M, Miyagishima SY. The YlmG protein has a conserved function related to the distribution of nucleoids in chloroplasts and cyanobacteria. BMC PLANT BIOLOGY 2010; 10:57. [PMID: 20359373 PMCID: PMC2923531 DOI: 10.1186/1471-2229-10-57] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Accepted: 04/02/2010] [Indexed: 05/18/2023]
Abstract
BACKGROUND Reminiscent of their free-living cyanobacterial ancestor, chloroplasts proliferate by division coupled with the partition of nucleoids (DNA-protein complexes). Division of the chloroplast envelope membrane is performed by constriction of the ring structures at the division site. During division, nucleoids also change their shape and are distributed essentially equally to the daughter chloroplasts. Although several components of the envelope division machinery have been identified and characterized, little is known about the molecular components/mechanisms underlying the change of the nucleoid structure. RESULTS In order to identify new factors that are involved in the chloroplast division, we isolated Arabidopsis thaliana chloroplast division mutants from a pool of random cDNA-overexpressed lines. We found that the overexpression of a previously uncharacterized gene (AtYLMG1-1) of cyanobacterial origin results in the formation of an irregular network of chloroplast nucleoids, along with a defect in chloroplast division. In contrast, knockdown of AtYLMG1-1 resulted in a concentration of the nucleoids into a few large structures, but did not affect chloroplast division. Immunofluorescence microscopy showed that AtYLMG1-1 localizes in small puncta on thylakoid membranes, to which a subset of nucleoids colocalize. In addition, in the cyanobacterium Synechococcus elongates, overexpression and deletion of ylmG also displayed defects in nucleoid structure and cell division. CONCLUSIONS These results suggest that the proper distribution of nucleoids requires the YlmG protein, and the mechanism is conserved between cyanobacteria and chloroplasts. Given that ylmG exists in a cell division gene cluster downstream of ftsZ in gram-positive bacteria and that ylmG overexpression impaired the chloroplast division, the nucleoid partitioning by YlmG might be related to chloroplast and cyanobacterial division processes.
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Affiliation(s)
- Yukihiro Kabeya
- Initiative Research Program, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hiromitsu Nakanishi
- Initiative Research Program, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kenji Suzuki
- Initiative Research Program, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Takanari Ichikawa
- Plant Functional Genomics Research Team, RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Youichi Kondou
- Plant Functional Genomics Research Team, RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Minami Matsui
- Plant Functional Genomics Research Team, RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Shin-ya Miyagishima
- Initiative Research Program, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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Cytochrome c biogenesis: mechanisms for covalent modifications and trafficking of heme and for heme-iron redox control. Microbiol Mol Biol Rev 2009; 73:510-28, Table of Contents. [PMID: 19721088 DOI: 10.1128/mmbr.00001-09] [Citation(s) in RCA: 198] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Heme is the prosthetic group for cytochromes, which are directly involved in oxidation/reduction reactions inside and outside the cell. Many cytochromes contain heme with covalent additions at one or both vinyl groups. These include farnesylation at one vinyl in hemes o and a and thioether linkages to each vinyl in cytochrome c (at CXXCH of the protein). Here we review the mechanisms for these covalent attachments, with emphasis on the three unique cytochrome c assembly pathways called systems I, II, and III. All proteins in system I (called Ccm proteins) and system II (Ccs proteins) are integral membrane proteins. Recent biochemical analyses suggest mechanisms for heme channeling to the outside, heme-iron redox control, and attachment to the CXXCH. For system II, the CcsB and CcsA proteins form a cytochrome c synthetase complex which specifically channels heme to an external heme binding domain; in this conserved tryptophan-rich "WWD domain" (in CcsA), the heme is maintained in the reduced state by two external histidines and then ligated to the CXXCH motif. In system I, a two-step process is described. Step 1 is the CcmABCD-mediated synthesis and release of oxidized holoCcmE (heme in the Fe(+3) state). We describe how external histidines in CcmC are involved in heme attachment to CcmE, and the chemical mechanism to form oxidized holoCcmE is discussed. Step 2 includes the CcmFH-mediated reduction (to Fe(+2)) of holoCcmE and ligation of the heme to CXXCH. The evolutionary and ecological advantages for each system are discussed with respect to iron limitation and oxidizing environments.
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Saint-Marcoux D, Wollman FA, de Vitry C. Biogenesis of cytochrome b6 in photosynthetic membranes. ACTA ACUST UNITED AC 2009; 185:1195-207. [PMID: 19564403 PMCID: PMC2712960 DOI: 10.1083/jcb.200812025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In chloroplasts, binding of a c′-heme to cytochrome b6 on the stromal side of the thylakoid membranes requires a specific mechanism distinct from the one at work for c-heme binding to cytochromes f and c6 on the lumenal side of membranes. Here, we show that the major protein components of this pathway, the CCBs, are bona fide transmembrane proteins. We demonstrate their association in a series of hetero-oligomeric complexes, some of which interact transiently with cytochrome b6 in the process of heme delivery to the apoprotein. In addition, we provide preliminary evidence for functional assembly of cytochrome b6f complexes even in the absence of c′-heme binding to cytochrome b6. Finally, we present a sequential model for apo- to holo-cytochrome b6 maturation integrated within the assembly pathway of b6f complexes in the thylakoid membranes.
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Affiliation(s)
- Denis Saint-Marcoux
- Centre National de la Recherche Scientifique, UMR 7141, Physiologie Membranaire et Moléculaire du Chloroplaste, Institut de Biologie Physico-Chimique, 75005 Paris, France
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de Lacroix de Lavalette A, Barucq L, Alric J, Rappaport F, Zito F. Is the redox state of the ci heme of the cytochrome b6f complex dependent on the occupation and structure of the Qi site and vice versa? J Biol Chem 2009; 284:20822-9. [PMID: 19478086 DOI: 10.1074/jbc.m109.016709] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Oxidoreductases of the cytochrome bc(1)/b(6)f family transfer electrons from a liposoluble quinol to a soluble acceptor protein and contribute to the formation of a transmembrane electrochemical potential. The crystal structure of cyt b(6)f has revealed the presence in the Q(i) site of an atypical c-type heme, heme c(i). Surprisingly, the protein does not provide any axial ligand to the iron of this heme, and its surrounding structure suggests it can be accessed by exogenous ligand. In this work we describe a mutagenesis approach aimed at characterizing the c(i) heme and its interaction with the Q(i) site environment. We engineered a mutant of Chlamydomonas reinhardtii in which Phe(40) from subunit IV was substituted by a tyrosine. This results in a dramatic slowing down of the reoxidation of the b hemes under single flash excitation, suggesting hindered accessibility of the heme to its quinone substrate. This modified accessibility likely originates from the ligation of the heme iron by the phenol(ate) side chain introduced by the mutation. Indeed, it also results in a marked downshift of the c(i) heme midpoint potential (from +100 mV to -200 mV at pH 7). Yet the overall turnover rate of the mutant cytochrome b(6)f complex under continuous illumination was found similar to the wild type one, both in vitro and in vivo. We propose that, in the mutant, a change in the ligation state of the heme upon its reduction could act as a redox switch that would control the accessibility of the substrate to the heme and trigger the catalysis.
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Ishikawa M, Fujiwara M, Sonoike K, Sato N. Orthogenomics of photosynthetic organisms: bioinformatic and experimental analysis of chloroplast proteins of endosymbiont origin in Arabidopsis and their counterparts in Synechocystis. PLANT & CELL PHYSIOLOGY 2009; 50:773-788. [PMID: 19224954 DOI: 10.1093/pcp/pcp027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Chloroplasts are descendents of a cyanobacterial endosymbiont, but many chloroplast protein genes of endosymbiont origin are encoded by the nucleus. The chloroplast-cyanobacteria relationship is a typical target of orthogenomics, an analytical method that focuses on the relationship of orthologous genes. Here, we present results of a pilot study of functional orthogenomics, combining bioinformatic and experimental analyses, to identify nuclear-encoded chloroplast proteins of endosymbiont origin (CPRENDOs). Phylogenetic profiling based on complete clustering of all proteins in 17 organisms, including eight cyanobacteria and two photosynthetic eukaryotes, was used to deduce 65 protein groups that are conserved in all oxygenic autotrophs analyzed but not in non-oxygenic organisms. With the exception of 28 well-characterized protein groups, 56 Arabidopsis proteins and 43 Synechocystis proteins in the 37 conserved homolog groups were analyzed. Green fluorescent protein (GFP) targeting experiments indicated that 54 Arabidopsis proteins were targeted to plastids. Expression of 39 Arabidopsis genes was promoted by light. Among the 40 disruptants of Synechocystis, 22 showed phenotypes related to photosynthesis. Arabidopsis mutants in 21 groups, including those reported previously, showed phenotypes. Characteristics of pulse amplitude modulation fluorescence were markedly different in corresponding mutants of Arabidopsis and Synechocystis in most cases. We conclude that phylogenetic profiling is useful in finding CPRENDOs, but the physiological functions of orthologous genes may be different in chloroplasts and cyanobacteria.
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Affiliation(s)
- Masayuki Ishikawa
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
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