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Nishimura Y. Plastid Nucleoids: Insights into Their Shape and Dynamics. PLANT & CELL PHYSIOLOGY 2024; 65:551-559. [PMID: 37542434 DOI: 10.1093/pcp/pcad090] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/26/2023] [Accepted: 08/04/2023] [Indexed: 08/07/2023]
Abstract
Chloroplasts/plastids are unique organelles found in plant cells and some algae and are responsible for performing essential functions such as photosynthesis. The plastid genome, consisting of circular and linear DNA molecules, is packaged and organized into specialized structures called nucleoids. The composition and dynamics of these nucleoids have been the subject of intense research, as they are critical for proper plastid functions and development. In this mini-review, recent advances in understanding the organization and regulation of plastid nucleoids are overviewed, with a focus on the various proteins and factors that regulate the shape and dynamics of nucleoids, including DNA-binding proteins and membrane anchorage proteins. The dynamic nature of nucleoid organization, which is influenced by a variety of developmental cues and the cell cycle, is also examined.
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Affiliation(s)
- Yoshiki Nishimura
- Department of Botany, Graduate School of Science, Kyoto University, Oiwake-cho, Kita-Shirakawa, Sakyo-ku, Kyoto, 606-8502 Japan
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Li QQ, Zhang ZP, Aogan, Wen J. Comparative chloroplast genomes of Argentina species: genome evolution and phylogenomic implications. FRONTIERS IN PLANT SCIENCE 2024; 15:1349358. [PMID: 38766467 PMCID: PMC11099909 DOI: 10.3389/fpls.2024.1349358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 03/25/2024] [Indexed: 05/22/2024]
Abstract
The genus Argentina Hill belongs to the tribe Potentilleae Sweet and contains approximately 75 species predominantly distributed in the Sino-Himalayan region and the Malesian archipelago. So far we have less knowledge on the phylogenetic relationships within Argentina owing to limited sampling of Argentina taxa or gene fragments in previous studies. Moreover, to date there is no phylogenetic study on Argentina from the perspective of comparative chloroplast (cp) genomics. Here we performed comparative genomic analyses on the cp genomes of 39 accessions representing 18 taxa of Argentina. The Argentina cp genomes presented the typical quadripartite structure, with the sizes ranging from 155 096 bp to 157 166 bp. The 39 Argentina cp genomes contained a set of 112 unique genes, comprising four ribosomal RNA (rRNA) genes, 30 transfer RNA (tRNA) genes, as well as 78 protein-coding genes (PCGs). The cp genome organization, gene content and order in Argentina were highly conserved, but some visible divergences were present in IR/SC boundary regions. Ten regions (trnH-GUG-psbA, trnG-GCC-trnfM-CAU, trnD-GUC-trnY-GUA, rpl32-trnL-UAG, atpH-atpI, rps16-trnQ-UUG, trnS-GCU-trnG-UCC, ndhF-rpl32, trnR-UCU-atpA, and accD-psaI) were identified as excellent candidate DNA markers for future studies on species identification, population genetics and phylogeny of Argentina. Our results indicated that Argentina is monophyletic. In the current sampling, the A. smithiana - A. anserina clade was sister to the remainder of Argentina. Our results corroborated the previous taxonomic treatments to transfer A. phanerophlebia and A. micropetala from the genus Sibbaldia L. to Argentina. Our results showed close relationships among A. stenophylla, A. microphylla, A. taliensis, and A. tatsienluensis, congruent with previous studies based on the morphology of these species. Twenty-six genes (rps3, rps15, rps16, rps19, rpl16, rpl20, rpl22, rpoA, rpoB, rpoC1, rpoC2, atpA, atpF, psbB, psbF, ndhA, ndhB, ndhC, ndhD, ndhF, rbcL, accD, ccsA, matK, ycf1, ycf2) were with sites under positive selection, and adaptive evolution of these genes might have played crucial roles in Argentina species adaptation to the harsh mountain environment. This study will facilitate future work on taxonomy, phylogenetics, and adaptive evolution of Argentina.
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Affiliation(s)
- Qin-Qin Li
- College of Life Science and Technology, Inner Mongolia Normal University, Hohhot, China
- Key Laboratory of Biodiversity Conservation and Sustainable Utilization in Mongolian Plateau for College and University of Inner Mongolia Autonomous Region, Hohhot, China
- Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States
| | - Zhi-Ping Zhang
- College of Computer Science and Technology, Inner Mongolia Normal University, Hohhot, China
| | - Aogan
- College of Life Science and Technology, Inner Mongolia Normal University, Hohhot, China
| | - Jun Wen
- Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States
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Nair A, Harshith CY, Narjala A, Shivaprasad PV. Begomoviral βC1 orchestrates organellar genomic instability to augment viral infection. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:934-950. [PMID: 36919198 DOI: 10.1111/tpj.16186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 03/04/2023] [Accepted: 03/10/2023] [Indexed: 05/27/2023]
Abstract
Chloroplast is the site for transforming light energy to chemical energy. It also acts as a production unit for a variety of defense-related molecules. These defense moieties are necessary to mount a successful counter defense against pathogens, including viruses. Previous studies indicated disruption of chloroplast homeostasis as a basic strategy of Begomovirus for its successful infection leading to the production of vein-clearing, mosaic, and chlorotic symptoms in infected plants. Although begomoviral pathogenicity determinant protein Beta C1 (βC1) was implicated for pathogenicity, the underlying mechanism was unclear. Here we show that, begomoviral βC1 directly interferes with the host plastid homeostasis. βC1 induced DPD1, an organelle-specific nuclease, implicated in nutrient salvage and senescence, as well as modulated the function of a major plastid genome maintainer protein RecA1, to subvert plastid genome. We show that βC1 was able to physically interact with bacterial RecA and its plant homolog RecA1, resulting in its altered activity. We observed that knocking-down DPD1 during virus infection significantly reduced virus-induced necrosis. These results indicate the presence of a strategy in which a viral protein alters host defense by targeting modulators of chloroplast DNA. We predict that the mechanism identified here might have similarities in other plant-pathogen interactions.
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Affiliation(s)
- Ashwin Nair
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore, 560065, India
- SASTRA University, Thirumalaisamudram, Thanjavur, 613401, India
| | - Chitthavalli Y Harshith
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore, 560065, India
| | - Anushree Narjala
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore, 560065, India
- SASTRA University, Thirumalaisamudram, Thanjavur, 613401, India
| | - Padubidri V Shivaprasad
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore, 560065, India
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Oetke S, Scheidig AJ, Krupinska K. WHIRLY1 of Barley and Maize Share a PRAPP Motif Conferring Nucleoid Compaction. PLANT & CELL PHYSIOLOGY 2022; 63:234-247. [PMID: 34792609 DOI: 10.1093/pcp/pcab164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/01/2021] [Accepted: 11/10/2021] [Indexed: 06/13/2023]
Abstract
WHIRLY1 in barley was shown to be a major architect of plastid nucleoids. Its accumulation in cells of Escherichia coli coincided with an induction of nucleoid compaction and growth retardation. While WHIRLY1 of maize had similar effects on E. coli cells, WHIRLY1 proteins of Arabidopsis and potato as well as WHIRLY2 proteins had no impact on nucleoid compaction in E. coli. By mutagenesis of HvWHIRLY1 the PRAPP motif at the N-terminus preceding the highly conserved WHIRLY domain was identified to be responsible for the nucleoid compacting activity of HvWHIRLY1 in bacteria. This motif is found in WHIRLY1 proteins of most members of the Poaceae family, but neither in the WHIRLY2 proteins of the family nor in any WHIRLY protein of eudicot species such as Arabidopsis thaliana. This finding indicates that a subset of the monocot WHIRLY1 proteins has acquired a specific function as nucleoid compacters by sequence variation in the N-terminal part preceding the conserved WHIRLY domain and that in different groups of higher plants the compaction of nucleoids is mediated by other proteins.
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Affiliation(s)
- Svenja Oetke
- Institute of Botany, Christian-Albrechts-University of Kiel, Am Botanischen Garten 7, 24118 Kiel, Germany
| | - Axel J Scheidig
- Institute of Zoology, Christian-Albrechts-University of Kiel, Am Botanischen Garten 7, 24118 Kiel, Germany
| | - Karin Krupinska
- Institute of Botany, Christian-Albrechts-University of Kiel, Am Botanischen Garten 7, 24118 Kiel, Germany
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Sanjaya A, Kazama Y, Ishii K, Muramatsu R, Kanamaru K, Ohbu S, Abe T, Fujiwara MT. An Argon-Ion-Induced Pale Green Mutant of Arabidopsis Exhibiting Rapid Disassembly of Mesophyll Chloroplast Grana. PLANTS (BASEL, SWITZERLAND) 2021; 10:848. [PMID: 33922223 PMCID: PMC8145761 DOI: 10.3390/plants10050848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/18/2021] [Accepted: 04/21/2021] [Indexed: 01/13/2023]
Abstract
Argon-ion beam is an effective mutagen capable of inducing a variety of mutation types. In this study, an argon ion-induced pale green mutant of Arabidopsis thaliana was isolated and characterized. The mutant, designated Ar50-33-pg1, exhibited moderate defects of growth and greening and exhibited rapid chlorosis in photosynthetic tissues. Fluorescence microscopy confirmed that mesophyll chloroplasts underwent substantial shrinkage during the chlorotic process. Genetic and whole-genome resequencing analyses revealed that Ar50-33-pg1 contained a large 940 kb deletion in chromosome V that encompassed more than 100 annotated genes, including 41 protein-coding genes such as TYRAAt1/TyrA1, EGY1, and MBD12. One of the deleted genes, EGY1, for a thylakoid membrane-localized metalloprotease, was the major contributory gene responsible for the pale mutant phenotype. Both an egy1 mutant and F1 progeny of an Ar50-33-pg1 × egy1 cross-exhibited chlorotic phenotypes similar to those of Ar50-33-pg1. Furthermore, ultrastructural analysis of mesophyll cells revealed that Ar50-33-pg1 and egy1 initially developed wild type-like chloroplasts, but these were rapidly disassembled, resulting in thylakoid disorganization and fragmentation, as well as plastoglobule accumulation, as terminal phenotypes. Together, these data support the utility of heavy-ion mutagenesis for plant genetic analysis and highlight the importance of EGY1 in the structural maintenance of grana in mesophyll chloroplasts.
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Affiliation(s)
- Alvin Sanjaya
- Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo 102-8554, Japan; (A.S.); (R.M.)
| | - Yusuke Kazama
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; (K.I.); (S.O.); (T.A.)
- Faculty of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji, Yoshida, Fukui 910-1195, Japan
| | - Kotaro Ishii
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; (K.I.); (S.O.); (T.A.)
| | - Ryohsuke Muramatsu
- Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo 102-8554, Japan; (A.S.); (R.M.)
| | - Kengo Kanamaru
- Faculty of Agriculture, Kobe University, Nada, Kobe, Hyogo 657-8501, Japan;
| | - Sumie Ohbu
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; (K.I.); (S.O.); (T.A.)
| | - Tomoko Abe
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; (K.I.); (S.O.); (T.A.)
| | - Makoto T. Fujiwara
- Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo 102-8554, Japan; (A.S.); (R.M.)
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; (K.I.); (S.O.); (T.A.)
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Méteignier L, Ghandour R, Meierhoff K, Zimmerman A, Chicher J, Baumberger N, Alioua A, Meurer J, Zoschke R, Hammani K. The Arabidopsis mTERF-repeat MDA1 protein plays a dual function in transcription and stabilization of specific chloroplast transcripts within the psbE and ndhH operons. THE NEW PHYTOLOGIST 2020; 227:1376-1391. [PMID: 32343843 PMCID: PMC7496394 DOI: 10.1111/nph.16625] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 04/15/2020] [Indexed: 05/28/2023]
Abstract
The mTERF gene family encodes for nucleic acid binding proteins that are predicted to regulate organellar gene expression in eukaryotes. Despite the implication of this gene family in plant development and response to abiotic stresses, a precise molecular function was assigned to only a handful number of its c. 30 members in plants. Using a reverse genetics approach in Arabidopsis thaliana and combining molecular and biochemical techniques, we revealed new functions for the chloroplast mTERF protein, MDA1. We demonstrated that MDA1 associates in vivo with components of the plastid-encoded RNA polymerase and transcriptional active chromosome complexes. MDA1 protein binds in vivo and in vitro with specificity to 27-bp DNA sequences near the 5'-end of psbE and ndhA chloroplast genes to stimulate their transcription, and additionally promotes the stabilization of the 5'-ends of processed psbE and ndhA messenger (m)RNAs. Finally, we provided evidence that MDA1 function in gene transcription likely coordinates RNA folding and the action of chloroplast RNA-binding proteins on mRNA stabilization. Our results provide examples for the unexpected implication of DNA binding proteins and gene transcription in the regulation of mRNA stability in chloroplasts, blurring the boundaries between DNA and RNA metabolism in this organelle.
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Affiliation(s)
- Louis‐Valentin Méteignier
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Rabea Ghandour
- Max Planck Institute of Molecular Plant PhysiologyAm Mühlenberg 114476Potsdam‐GolmGermany
| | - Karin Meierhoff
- Institute of Developmental and Molecular Biology of PlantsHeinrich Heine University Düsseldorf40225DüsseldorfGermany
| | - Aude Zimmerman
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Johana Chicher
- Plateforme protéomique Strasbourg Esplanade FRC1589 du CNRSUniversité de Strasbourg15 rue René Descartes67084StrasbourgFrance
| | - Nicolas Baumberger
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Abdelmalek Alioua
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Jörg Meurer
- Plant SciencesFaculty of BiologyLudwig‐Maximilians‐University MunichGroßhaderner Street 2‐482152Planegg‐MartinsriedGermany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant PhysiologyAm Mühlenberg 114476Potsdam‐GolmGermany
| | - Kamel Hammani
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
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Lee HG, Kim HM, Min J, Park C, Jeong HJ, Lee K, Kim KY. Quantification of the paralytic shellfish poisoning dinoflagellate Alexandrium species using a digital PCR. HARMFUL ALGAE 2020; 92:101726. [PMID: 32113599 DOI: 10.1016/j.hal.2019.101726] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 12/01/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
A ubiquitous dinoflagellate, Alexandrium, produces paralytic shellfish toxin (PST), and its outbreaks have negative impacts on aquaculture, fisheries, human health, and the marine ecosystem. To minimize such damages, a routine monitoring program of toxic species must be implemented with a suitable analytical technique for their identification and quantification. However, the taxonomic identification and cell quantification of Alexandrium species based on their external morphology under a light microscope, or by using conventional molecular approaches have limited sensitivity and reproducibility. To address these challenges, we have developed an advanced protocol using droplet-digital PCR (ddPCR) for the discrimination and enumeration of three co-occurring Alexandrium species (A. affine, A. catenella, and A. pacificum) in environmental samples. Copies of species-specific internal transcribed spacer (ITS) per cell, which were calculated from environmental samples spiked with various numbers of culture cells, were used to estimate the abundance of species in the field samples. There were no significant differences in ITS copies estimated by the digital PCR assay between environmental samples from different localities, spiked artificially with a consistent number of cells from Alexandrium cultures. This sensitive assay was applied to determine the abundance and vertical distribution of those populations in the southern coastal waters of Korea. In spring, A. catenella was the dominant species, followed by the non-toxic A. affine in summers. A novel digital PCR assay can also be used to monitor other harmful marine protists that require high sample throughput and low detection limit with high accuracy and precision.
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Affiliation(s)
- Hyun-Gwan Lee
- Department of Oceanography, College of Natural Sciences, Chonnam National University, Gwangju 61186, Republic of Korea; Marine Ecosystem Disturbing and Harmful Organisms (MEDHO) Research Center, Gwangju 61186, Republic of Korea
| | - Hye Mi Kim
- Department of Oceanography, College of Natural Sciences, Chonnam National University, Gwangju 61186, Republic of Korea; Marine Ecosystem Disturbing and Harmful Organisms (MEDHO) Research Center, Gwangju 61186, Republic of Korea
| | - Juhee Min
- Department of Oceanography, College of Natural Sciences, Chonnam National University, Gwangju 61186, Republic of Korea; Marine Ecosystem Disturbing and Harmful Organisms (MEDHO) Research Center, Gwangju 61186, Republic of Korea
| | - Chungoo Park
- Marine Ecosystem Disturbing and Harmful Organisms (MEDHO) Research Center, Gwangju 61186, Republic of Korea; School of Biological Sciences and Technology, College of Natural Sciences, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Hae Jin Jeong
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kitack Lee
- School of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Kwang Young Kim
- Department of Oceanography, College of Natural Sciences, Chonnam National University, Gwangju 61186, Republic of Korea; Marine Ecosystem Disturbing and Harmful Organisms (MEDHO) Research Center, Gwangju 61186, Republic of Korea.
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Chevigny N, Schatz-Daas D, Lotfi F, Gualberto JM. DNA Repair and the Stability of the Plant Mitochondrial Genome. Int J Mol Sci 2020; 21:E328. [PMID: 31947741 PMCID: PMC6981420 DOI: 10.3390/ijms21010328] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 12/27/2019] [Accepted: 01/01/2020] [Indexed: 12/13/2022] Open
Abstract
The mitochondrion stands at the center of cell energy metabolism. It contains its own genome, the mtDNA, that is a relic of its prokaryotic symbiotic ancestor. In plants, the mitochondrial genetic information influences important agronomic traits including fertility, plant vigor, chloroplast function, and cross-compatibility. Plant mtDNA has remarkable characteristics: It is much larger than the mtDNA of other eukaryotes and evolves very rapidly in structure. This is because of recombination activities that generate alternative mtDNA configurations, an important reservoir of genetic diversity that promotes rapid mtDNA evolution. On the other hand, the high incidence of ectopic recombination leads to mtDNA instability and the expression of gene chimeras, with potential deleterious effects. In contrast to the structural plasticity of the genome, in most plant species the mtDNA coding sequences evolve very slowly, even if the organization of the genome is highly variable. Repair mechanisms are probably responsible for such low mutation rates, in particular repair by homologous recombination. Herein we review some of the characteristics of plant organellar genomes and of the repair pathways found in plant mitochondria. We further discuss how homologous recombination is involved in the evolution of the plant mtDNA.
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Affiliation(s)
| | | | | | - José Manuel Gualberto
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 67081 Strasbourg, France; (N.C.); (D.S.-D.); (F.L.)
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Abstract
The evolutionary processes that transitioned plants to land-based habitats also incorporated a multiplicity of strategies to enhance resilience to the greater environmental variation encountered on land. The sensing of light, its quality, quantity, and duration, is central to plant survival and, as such, serves as a central network hub. Similarly, plants as sessile organisms that can encounter isolation must continually assess their reproductive options, requiring plasticity in propagation by self- and cross-pollination or asexual strategies. Irregular fluctuations and intermittent extremes in temperature, soil fertility, and moisture conditions have given impetus to genetic specializations for network resiliency, protein neofunctionalization, and internal mechanisms to accelerate their evolution. We review some of the current advancements made in understanding plant resiliency and phenotypic plasticity mechanisms. These mechanisms incorporate unusual nuclear-cytoplasmic interactions, various transposable element (TE) activities, and epigenetic plasticity of central gene networks that are broadly pleiotropic to influence resiliency phenotypes.
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Affiliation(s)
- Xiaodong Yang
- Departments of Biology and Plant Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Sally A Mackenzie
- Departments of Biology and Plant Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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10
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Plant Organelle Genome Replication. PLANTS 2019; 8:plants8100358. [PMID: 31546578 PMCID: PMC6843274 DOI: 10.3390/plants8100358] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/14/2019] [Accepted: 09/18/2019] [Indexed: 12/21/2022]
Abstract
Mitochondria and chloroplasts perform essential functions in respiration, ATP production, and photosynthesis, and both organelles contain genomes that encode only some of the proteins that are required for these functions. The proteins and mechanisms for organelle DNA replication are very similar to bacterial or phage systems. The minimal replisome may consist of DNA polymerase, a primase/helicase, and a single-stranded DNA binding protein (SSB), similar to that found in bacteriophage T7. In Arabidopsis, there are two genes for organellar DNA polymerases and multiple potential genes for SSB, but there is only one known primase/helicase protein to date. Genome copy number varies widely between type and age of plant tissues. Replication mechanisms are only poorly understood at present, and may involve multiple processes, including recombination-dependent replication (RDR) in plant mitochondria and perhaps also in chloroplasts. There are still important questions remaining as to how the genomes are maintained in new organelles, and how genome copy number is determined. This review summarizes our current understanding of these processes.
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11
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Li-Beisson Y, Thelen JJ, Fedosejevs E, Harwood JL. The lipid biochemistry of eukaryotic algae. Prog Lipid Res 2019; 74:31-68. [PMID: 30703388 DOI: 10.1016/j.plipres.2019.01.003] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/06/2023]
Abstract
Algal lipid metabolism fascinates both scientists and entrepreneurs due to the large diversity of fatty acyl structures that algae produce. Algae have therefore long been studied as sources of genes for novel fatty acids; and, due to their superior biomass productivity, algae are also considered a potential feedstock for biofuels. However, a major issue in a commercially viable "algal oil-to-biofuel" industry is the high production cost, because most algal species only produce large amounts of oils after being exposed to stress conditions. Recent studies have therefore focused on the identification of factors involved in TAG metabolism, on the subcellular organization of lipid pathways, and on interactions between organelles. This has been accompanied by the development of genetic/genomic and synthetic biological tools not only for the reference green alga Chlamydomonas reinhardtii but also for Nannochloropsis spp. and Phaeodactylum tricornutum. Advances in our understanding of enzymes and regulatory proteins of acyl lipid biosynthesis and turnover are described herein with a focus on carbon and energetic aspects. We also summarize how changes in environmental factors can impact lipid metabolism and describe present and potential industrial uses of algal lipids.
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Affiliation(s)
- Yonghua Li-Beisson
- Aix-Marseille Univ, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F-13108, France.
| | - Jay J Thelen
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - Eric Fedosejevs
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
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Sakamoto W, Takami T. Chloroplast DNA Dynamics: Copy Number, Quality Control and Degradation. PLANT & CELL PHYSIOLOGY 2018; 59:1120-1127. [PMID: 29860378 DOI: 10.1093/pcp/pcy084] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/01/2018] [Indexed: 05/16/2023]
Abstract
Endosymbiotically originated chloroplast DNA (cpDNA) encodes part of the genetic information needed to fulfill chloroplast function, including fundamental processes such as photosynthesis. In the last two decades, advances in genome analysis led to the identification of a considerable number of cpDNA sequences from various species. While these data provided the consensus features of cpDNA organization and chloroplast evolution in plants, how cpDNA is maintained through development and is inherited remains to be fully understood. In particular, the fact that cpDNA exists as multiple copies despite its limited genetic capacity raises the important question of how copy number is maintained or whether cpDNA is subjected to quantitative fluctuation or even developmental degradation. For example, cpDNA is abundant in leaves, where it forms punctate structures called nucleoids, which seemingly alter their morphologies and numbers depending on the developmental status of the chloroplast. In this review, we summarize our current understanding of 'cpDNA dynamics', focusing on the changes in DNA abundance. A special focus is given to the cpDNA degradation mechanism, which appears to be mediated by Defective in Pollen organelle DNA degradation 1 (DPD1), a recently discovered organelle exonuclease. The physiological significance of cpDNA degradation in flowering plants is also discussed.
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Affiliation(s)
- Wataru Sakamoto
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046 Japan
| | - Tsuneaki Takami
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046 Japan
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Shi M, Zhang X, Pei G, Chen L, Zhang W. Functional Diversity of Transcriptional Regulators in the Cyanobacterium Synechocystis sp. PCC 6803. Front Microbiol 2017; 8:280. [PMID: 28270809 PMCID: PMC5318462 DOI: 10.3389/fmicb.2017.00280] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 02/09/2017] [Indexed: 11/16/2022] Open
Abstract
Functions of transcriptional regulators (TRs) are still poorly understood in the model cyanobacterium Synechocystis sp. PCC 6803. To address the issue, we constructed knockout mutants for 32 putative TR-encoding genes of Synechocystis, and comparatively analyzed their phenotypes under autotrophic growth condition and metabolic profiles using liquid chromatography-mass spectrometry-based metabolomics. The results showed that only four mutants of TR genes, sll1872 (lytR), slr0741 (phoU), slr0395 (ntcB), and slr1871 (pirR), showed differential growth patterns in BG11 medium when compared with the wild type; however, in spite of no growth difference observed for the remaining TR mutants, metabolomic profiling showed that they were different at the metabolite level, suggesting significant functional diversity of TRs in Synechocystis. In addition, an integrative metabolomic and gene families’ analysis of all TR mutants led to the identification of five pairs of TR genes that each shared close relationship in both gene families and metabolomic clustering trees, suggesting possible conserved functions of these TRs during evolution. Moreover, more than a dozen pairs of TR genes with different origin and evolution were found with similar metabolomic profiles, suggesting a possible functional convergence of the TRs during genome evolution. Finally, a protein–protein network analysis was performed to predict regulatory targets of TRs, allowing inference of possible regulatory gene targets for 4 out of five pairs of TRs. This study provided new insights into the regulatory functions and evolution of TR genes in Synechocystis.
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Affiliation(s)
- Mengliang Shi
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China
| | - Xiaoqing Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China
| | - Guangsheng Pei
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China; Center for Biosafety Research and Strategy, Tianjin UniversityTianjin, China
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Multifunctionality of plastid nucleoids as revealed by proteome analyses. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1016-38. [PMID: 26987276 DOI: 10.1016/j.bbapap.2016.03.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 02/25/2016] [Accepted: 03/09/2016] [Indexed: 01/08/2023]
Abstract
Protocols aimed at the isolation of nucleoids and transcriptionally active chromosomes (TACs) from plastids of higher plants have been established already decades ago, but only recent improvements in the mass spectrometry methods enabled detailed proteomic characterization of their components. Here we present a comprehensive analysis of the protein compositions obtained from two proteomic studies of TAC fractions isolated from Arabidopsis/mustard and spinach chloroplasts, respectively, as well as nucleoid fractions from Arabidopsis, maize and pea. Interestingly, different approaches as well as the use of diverse starting materials resulted in the detection of varying protein catalogues with a number of shared proteins. Possible reasons for the discrepancies between the protein repertoires and for missing out some of the nucleoid proteins that have been identified previously by other means than mass spectrometry as well as the repeated identification of "unexpected" proteins indicating potential links between DNA/RNA-associated nucleoid core functions and energy metabolism as well as biosynthetic activities of plastids will be discussed. In accordance with the nucleoid association of proteins involved in key functions of plastids including photosynthesis, the phenotypes of mutants lacking one or the other plastid nucleoid-associated protein (ptNAP) show the importance of nucleoid proteins for overall plant development and growth. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock.
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Kobayashi Y, Takusagawa M, Harada N, Fukao Y, Yamaoka S, Kohchi T, Hori K, Ohta H, Shikanai T, Nishimura Y. Eukaryotic Components Remodeled Chloroplast Nucleoid Organization during the Green Plant Evolution. Genome Biol Evol 2015; 8:1-16. [PMID: 26608058 PMCID: PMC4758235 DOI: 10.1093/gbe/evv233] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Chloroplast (cp) DNA is thought to originate from the ancestral endosymbiont genome and is compacted to form nucleoprotein complexes, cp nucleoids. The structure of cp nucleoids is ubiquitously observed in diverse plants from unicellular algae to flowering plants and is believed to be a multifunctional platform for various processes, including cpDNA replication, repair/recombination, transcription, and inheritance. Despite its fundamental functions, the protein composition for cp nucleoids in flowering plants was suggested to be divergent from those of bacteria and algae, but the evolutionary process remains elusive. In this research, we aimed to reveal the evolutionary history of cp nucleoid organization by analyzing the key organisms representing the three evolutionary stages of eukaryotic phototrophs: the chlorophyte alga Chlamydomonas reinhardtii, the charophyte alga Klebsormidium flaccidum, and the most basal land plant Marchantia polymorpha. To clarify the core cp nucleoid proteins in C. reinhardtii, we performed an LC-MS/MS analysis using highly purified cp nucleoid fractions and identified a novel SAP domain-containing protein with a eukaryotic origin as a constitutive core component. Then, homologous genes for cp nucleoid proteins were searched for in C. reinhardtii, K. flaccidum, and M. polymorpha using the genome databases, and their intracellular localizations and DNA binding activities were investigated by cell biological/biochemical analyses. Based on these results, we propose a model that recurrent modification of cp nucleoid organization by eukaryotic factors originally related to chromatin organization might have been the driving force for the diversification of cp nucleoids since the early stage of green plant evolution.
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Affiliation(s)
- Yusuke Kobayashi
- Laboratory of Plant Molecular Genetics, Department of Botany, Kyoto University, Oiwake-Cho, Kita-Shirakawa, Kyoto, Japan
| | - Mari Takusagawa
- Laboratory of Plant Molecular Genetics, Department of Botany, Kyoto University, Oiwake-Cho, Kita-Shirakawa, Kyoto, Japan Department of Biological Science and Chemistry, Faculty of Science, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Naomi Harada
- Laboratory of Plant Molecular Genetics, Department of Botany, Kyoto University, Oiwake-Cho, Kita-Shirakawa, Kyoto, Japan
| | - Yoichiro Fukao
- Plant Global Educational Project, and Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan Department of Bioinformatics, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Shohei Yamaoka
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Koichi Hori
- Tokyo Institute of Technology, Graduate School of Bioscience and Biotechnology, Yokohama City, Kanagawa, Japan
| | - Hiroyuki Ohta
- Tokyo Institute of Technology, Graduate School of Bioscience and Biotechnology, Yokohama City, Kanagawa, Japan Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-Ku, Tokyo, Japan
| | - Toshiharu Shikanai
- Laboratory of Plant Molecular Genetics, Department of Botany, Kyoto University, Oiwake-Cho, Kita-Shirakawa, Kyoto, Japan
| | - Yoshiki Nishimura
- Laboratory of Plant Molecular Genetics, Department of Botany, Kyoto University, Oiwake-Cho, Kita-Shirakawa, Kyoto, Japan
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16
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Moriyama T, Tajima N, Sekine K, Sato N. Localization and phylogenetic analysis of enzymes related to organellar genome replication in the unicellular rhodophyte Cyanidioschyzon merolae. Genome Biol Evol 2014; 6:228-37. [PMID: 24407855 PMCID: PMC3914683 DOI: 10.1093/gbe/evu009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Plants and algae possess plastids and mitochondria harboring their own genomes, which are replicated by the apparatus consisting of DNA polymerase, DNA primase, DNA helicase, DNA topoisomerase, single-stranded DNA maintenance protein, DNA ligase, and primer removal enzyme. In the higher plant Arabidopsis thaliana, organellar replication-related enzymes (OREs) are similar in plastids and mitochondria because many of them are dually targeted to plastids and mitochondria. In the red algae, there is a report about a DNA replicase, plant/protist organellar DNA polymerase, which is localized to both plastids and mitochondria. However, other OREs remain unclear in algae. Here, we identified OREs possibly localized to organelles in the unicellular rhodophyte Cyanidioschyzon merolae. We then examined intracellular localization of green fluorescent protein-fusion proteins of these enzymes in C. merolae, whose cell has a single plastid and a single mitochondrion and is suitable for localization analysis, demonstrating that the plastid and the mitochondrion contain markedly different components of replication machinery. Phylogenetic analyses revealed that the organelle replication apparatus was composed of enzymes of various different origins, such as proteobacterial, cyanobacterial, and eukaryotic, in both red algae and green plants. Especially in the red alga, many enzymes of cyanobacterial origin remained. Finally, on the basis of the results of localization and phylogenetic analyses, we propose a model on the succession of OREs in eukaryotes.
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Affiliation(s)
- Takashi Moriyama
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Japan
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18
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Moriyama T, Sato N. Enzymes involved in organellar DNA replication in photosynthetic eukaryotes. FRONTIERS IN PLANT SCIENCE 2014; 5:480. [PMID: 25278952 PMCID: PMC4166229 DOI: 10.3389/fpls.2014.00480] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 08/30/2014] [Indexed: 05/18/2023]
Abstract
Plastids and mitochondria possess their own genomes. Although the replication mechanisms of these organellar genomes remain unclear in photosynthetic eukaryotes, several organelle-localized enzymes related to genome replication, including DNA polymerase, DNA primase, DNA helicase, DNA topoisomerase, single-stranded DNA maintenance protein, DNA ligase, primer removal enzyme, and several DNA recombination-related enzymes, have been identified. In the reference Eudicot plant Arabidopsis thaliana, the replication-related enzymes of plastids and mitochondria are similar because many of them are dual targeted to both organelles, whereas in the red alga Cyanidioschyzon merolae, plastids and mitochondria contain different replication machinery components. The enzymes involved in organellar genome replication in green plants and red algae were derived from different origins, including proteobacterial, cyanobacterial, and eukaryotic lineages. In the present review, we summarize the available data for enzymes related to organellar genome replication in green plants and red algae. In addition, based on the type and distribution of replication enzymes in photosynthetic eukaryotes, we discuss the transitional history of replication enzymes in the organelles of plants.
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Affiliation(s)
- Takashi Moriyama
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of TokyoTokyo, Japan
- Japan Science and Technology Agency – Core Research for Evolutional Science and TechnologyTokyo, Japan
| | - Naoki Sato
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of TokyoTokyo, Japan
- Japan Science and Technology Agency – Core Research for Evolutional Science and TechnologyTokyo, Japan
- *Correspondence: Naoki Sato, Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan e-mail:
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Powikrowska M, Oetke S, Jensen PE, Krupinska K. Dynamic composition, shaping and organization of plastid nucleoids. FRONTIERS IN PLANT SCIENCE 2014; 5:424. [PMID: 25237313 PMCID: PMC4154389 DOI: 10.3389/fpls.2014.00424] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 08/08/2014] [Indexed: 05/18/2023]
Abstract
In this article recent progress on the elucidation of the dynamic composition and structure of plastid nucleoids is reviewed from a structural perspective. Plastid nucleoids are compact structures of multiple copies of different forms of ptDNA, RNA, enzymes for replication and gene expression as well as DNA binding proteins. Although early electron microscopy suggested that plastid DNA is almost free of proteins, it is now well established that the DNA in nucleoids similarly as in the nuclear chromatin is associated with basic proteins playing key roles in organization of the DNA architecture and in regulation of DNA associated enzymatic activities involved in transcription, replication, and recombination. This group of DNA binding proteins has been named plastid nucleoid associated proteins (ptNAPs). Plastid nucleoids are unique with respect to their variable number, genome copy content and dynamic distribution within different types of plastids. The mechanisms underlying the shaping and reorganization of plastid nucleoids during chloroplast development and in response to environmental conditions involve posttranslational modifications of ptNAPs, similarly to those changes known for histones in the eukaryotic chromatin, as well as changes in the repertoire of ptNAPs, as known for nucleoids of bacteria. Attachment of plastid nucleoids to membranes is proposed to be important not only for regulation of DNA availability for replication and transcription, but also for the coordination of photosynthesis and plastid gene expression.
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Affiliation(s)
- Marta Powikrowska
- Department of Plant and Environmental Sciences, VILLUM Research Centre for Plant Plasticity and Copenhagen Plant Science Centre, University of CopenhagenCopenhagen, Denmark
| | - Svenja Oetke
- Plant Cell Biology, Institute of Botany, Christian-Albrechts-University of KielKiel, Germany
| | - Poul E. Jensen
- Department of Plant and Environmental Sciences, VILLUM Research Centre for Plant Plasticity and Copenhagen Plant Science Centre, University of CopenhagenCopenhagen, Denmark
| | - Karin Krupinska
- Plant Cell Biology, Institute of Botany, Christian-Albrechts-University of KielKiel, Germany
- *Correspondence: Karin Krupinska, Plant Cell Biology, Institute of Botany, Christian-Albrechts-University of Kiel, Olshausenstrasse 40, 24098 Kiel, Germany e-mail:
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20
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Finster S, Eggert E, Zoschke R, Weihe A, Schmitz-Linneweber C. Light-dependent, plastome-wide association of the plastid-encoded RNA polymerase with chloroplast DNA. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 76:849-60. [PMID: 24118403 DOI: 10.1111/tpj.12339] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 09/05/2013] [Accepted: 09/25/2013] [Indexed: 05/04/2023]
Abstract
Plastid genes are transcribed by two types of RNA polymerases: a plastid-encoded eubacterial-type RNA polymerase (PEP) and nuclear-encoded phage-type RNA polymerases (NEPs). To investigate the spatio-temporal expression of PEP, we tagged its α-subunit with a hemagglutinin epitope (HA). Transplastomic tobacco plants were generated and analyzed for the distribution of the tagged polymerase in plastid sub-fractions, and associated genes were identified under various light conditions. RpoA:HA was detected as early as the 3rd day after imbibition, and was constitutively expressed in green tissue over 60 days of plant development. We found that the tagged polymerase subunit preferentially associated with the plastid membranes, and was less abundant in the soluble stroma fraction. Attachment of RpoA:HA to the membrane fraction during early seedling development was independent of DNA, but at later stages of development, DNA appears to facilitate attachment of the polymerase to membranes. To survey PEP-dependent transcription units, we probed for nucleic acids enriched in RpoA:HA precipitates using a tobacco chloroplast whole-genome tiling array. The most strongly co-enriched DNA fragments represent photosynthesis genes (e.g. psbA, psbC, psbD and rbcL), whose expression is known to be driven by PEP promoters, while NEP-dependent genes were less abundant in RpoA:HA precipitates. Additionally, we demonstrate that the association of PEP with photosynthesis-related genes was reduced during the dark period, indicating that plastome-wide PEP-DNA association is a light-dependent process.
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Affiliation(s)
- Sabrina Finster
- Institut für Biologie, Humboldt-Universität Berlin, Chausseestraße 117, 10115, Berlin, Germany
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21
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Botté CY, Yamaryo-Botté Y, Rupasinghe TWT, Mullin KA, MacRae JI, Spurck TP, Kalanon M, Shears MJ, Coppel RL, Crellin PK, Maréchal E, McConville MJ, McFadden GI. Atypical lipid composition in the purified relict plastid (apicoplast) of malaria parasites. Proc Natl Acad Sci U S A 2013; 110:7506-11. [PMID: 23589867 PMCID: PMC3645554 DOI: 10.1073/pnas.1301251110] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The human malaria parasite Plasmodium falciparum harbors a relict, nonphotosynthetic plastid of algal origin termed the apicoplast. Although considerable progress has been made in defining the metabolic functions of the apicoplast, information on the composition and biogenesis of the four delimiting membranes of this organelle is limited. Here, we report an efficient method for preparing highly purified apicoplasts from red blood cell parasite stages and the comprehensive lipidomic analysis of this organelle. Apicoplasts were prepared from transgenic parasites expressing an epitope-tagged triosephosphate transporter and immunopurified on magnetic beads. Gas and liquid chromatography MS analyses of isolated apicoplast lipids indicated significant differences compared with total parasite lipids. In particular, apicoplasts were highly enriched in phosphatidylinositol, consistent with a suggested role for phosphoinositides in targeting membrane vesicles to apicoplasts. Apicoplast phosphatidylinositol and other phospholipids were also enriched in saturated fatty acids, which could reflect limited acyl exchange with other membrane phospholipids and/or a requirement for specific physical properties. Lipids atypical for plastids (sphingomyelins, ceramides, and cholesterol) were detected in apicoplasts. The presence of cholesterol in apicoplast membranes was supported by filipin staining of isolated apicoplasts. Galactoglycerolipids, dominant in plant and algal plastids, were not detected in P. falciparum apicoplasts, suggesting that these glycolipids are a hallmark of photosynthetic plastids and were lost when these organisms assumed a parasitic lifestyle. Apicoplasts thus contain an atypical melange of lipids scavenged from the human host alongside lipids remodeled by the parasite cytoplasm, and stable isotope labeling shows some apicoplast lipids are generated de novo by the organelle itself.
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Affiliation(s)
- Cyrille Y. Botté
- School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
- Unité Mixte de Recherche (UMR) 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique (CEA), Institut National des Recherches Agronomiques (INRA), Université Grenoble I, Institut de Recherches en Technologies et Sciences du Vivant (iRTSV), CEA Grenoble, 38054 Grenoble, France
- Laboratoire Adaptation et Pathogenie des Microorganismes, Unité Mixte de Recherche (UMR) 5163, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Université Grenoble I, 38700 La Tronche, France
| | - Yoshiki Yamaryo-Botté
- Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
- Department of Biochemistry and Molecular Biology, and Bio21 Institute of Molecular Science and Biotechnology University of Melbourne, Parkville, VIC 3052, Australia; and
| | | | - Kylie A. Mullin
- School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - James I. MacRae
- Department of Biochemistry and Molecular Biology, and Bio21 Institute of Molecular Science and Biotechnology University of Melbourne, Parkville, VIC 3052, Australia; and
| | - Timothy P. Spurck
- School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Ming Kalanon
- School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Melanie J. Shears
- School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Ross L. Coppel
- Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Paul K. Crellin
- Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Eric Maréchal
- Unité Mixte de Recherche (UMR) 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique (CEA), Institut National des Recherches Agronomiques (INRA), Université Grenoble I, Institut de Recherches en Technologies et Sciences du Vivant (iRTSV), CEA Grenoble, 38054 Grenoble, France
| | - Malcolm J. McConville
- Department of Biochemistry and Molecular Biology, and Bio21 Institute of Molecular Science and Biotechnology University of Melbourne, Parkville, VIC 3052, Australia; and
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Pfalz J, Pfannschmidt T. Essential nucleoid proteins in early chloroplast development. TRENDS IN PLANT SCIENCE 2013; 18:186-94. [PMID: 23246438 DOI: 10.1016/j.tplants.2012.11.003] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 11/01/2012] [Accepted: 11/12/2012] [Indexed: 05/04/2023]
Abstract
The plastid transcription machinery can be biochemically purified at different organisational levels as soluble RNA polymerase, transcriptionally active chromosome, or nucleoid. Recent proteomic studies have uncovered several novel proteins in these structures and functional genomic studies have indicated that a lack of many of these proteins results in chlorotic phenotypes of varying degree. The most severe cases exhibit complete albino phenotypes, which led to the conclusion that the proteins that were lacking had important regulatory roles in plastid gene expression and chloroplast development. In this opinion article, we propose an alternative model in which the structural establishment of a transcriptional subdomain within the nucleoid represents an early developmental bottleneck that leads to abortion of proper chloroplast biogenesis if disturbed.
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Affiliation(s)
- Jeannette Pfalz
- Department of Plant Physiology, Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, D-07743 Jena, Germany
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23
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Krupinska K, Melonek J, Krause K. New insights into plastid nucleoid structure and functionality. PLANTA 2013; 237:653-64. [PMID: 23212213 DOI: 10.1007/s00425-012-1817-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 11/09/2012] [Indexed: 05/04/2023]
Abstract
Investigations over many decades have revealed that nucleoids of higher plant plastids are highly dynamic with regard to their number, their structural organization and protein composition. Membrane attachment and environmental cues seem to determine the activity and functionality of the nucleoids and point to a highly regulated structure-function relationship. The heterogeneous composition and the many functions that are seemingly associated with the plastid nucleoids could be related to the high number of chromosomes per plastid. Recent proteomic studies have brought novel nucleoid-associated proteins into the spotlight and indicated that plastid nucleoids are an evolutionary hybrid possessing prokaryotic nucleoid features and eukaryotic (nuclear) chromatin components, several of which are dually targeted to the nucleus and chloroplasts. Future studies need to unravel if and how plastid-nucleus communication depends on nucleoid structure and plastid gene expression.
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Affiliation(s)
- Karin Krupinska
- Institute of Botany, University of Kiel, Olshausenstraße 40, 24098, Kiel, Germany.
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Yagi Y, Shiina T. Evolutionary aspects of plastid proteins involved in transcription: the transcription of a tiny genome is mediated by a complicated machinery. Transcription 2012; 3:290-4. [PMID: 22889841 PMCID: PMC3630183 DOI: 10.4161/trns.21810] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Chloroplasts in land plants have a small genome consisting of only 100 genes encoding partial sets of proteins for photosynthesis, transcription and translation. Although it has been thought that chloroplast transcription is mediated by a basically cyanobacterium-derived system, due to the endosymbiotic origin of plastids, recent studies suggest the existence of a hybrid transcription machinery containing non-bacterial proteins that have been newly acquired during plant evolution. Here, we highlight chloroplast-specific non-bacterial transcription mechanisms by which land plant chloroplasts have gained novel functions.
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Affiliation(s)
- Yusuke Yagi
- Faculty of Agriculture, Kyushu University, Fukuoka, Japan
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25
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Newell CA, Natesan SKA, Sullivan JA, Jouhet J, Kavanagh TA, Gray JC. Exclusion of plastid nucleoids and ribosomes from stromules in tobacco and Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 69:399-410. [PMID: 21951134 DOI: 10.1111/j.1365-313x.2011.04798.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Stromules are stroma-filled tubules that extend from the surface of plastids and allow the transfer of proteins as large as 550 kDa between interconnected plastids. The aim of the present study was to determine if plastid DNA or plastid ribosomes are able to enter stromules, potentially permitting the transfer of genetic information between plastids. Plastid DNA and ribosomes were marked with green fluorescent protein (GFP) fusions to LacI, the lac repressor, which binds to lacO-related sequences in plastid DNA, and to plastid ribosomal proteins Rpl1 and Rps2, respectively. Fluorescence from GFP-LacI co-localised with plastid DNA in nucleoids in all tissues of transgenic tobacco (Nicotiana tabacum L.) examined and there was no indication of its presence in stromules, not even in hypocotyl epidermal cells, which contain abundant stromules. Fluorescence from Rpl1-GFP and Rps2-GFP was also observed in a punctate pattern in chloroplasts of tobacco and Arabidopsis [Arabidopsis thaliana (L.) Heynh.], and fluorescent stromules were not detected. Rpl1-GFP was shown to assemble into ribosomes and was co-localised with plastid DNA. In contrast, in hypocotyl epidermal cells of dark-grown Arabidopsis seedlings, fluorescence from Rpl1-GFP was more evenly distributed in plastids and was observed in stromules on a total of only four plastids (<0.02% of the plastids observed). These observations indicate that plastid DNA and plastid ribosomes do not routinely move into stromules in tobacco and Arabidopsis, and suggest that transfer of genetic information by this route is likely to be a very rare event, if it occurs at all.
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Affiliation(s)
- Christine A Newell
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
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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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Gao ZP, Yu QB, Zhao TT, Ma Q, Chen GX, Yang ZN. A functional component of the transcriptionally active chromosome complex, Arabidopsis pTAC14, interacts with pTAC12/HEMERA and regulates plastid gene expression. PLANT PHYSIOLOGY 2011; 157:1733-45. [PMID: 22010110 PMCID: PMC3327189 DOI: 10.1104/pp.111.184762] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 10/14/2011] [Indexed: 05/18/2023]
Abstract
The SET domain-containing protein, pTAC14, was previously identified as a component of the transcriptionally active chromosome (TAC) complexes. Here, we investigated the function of pTAC14 in the regulation of plastid-encoded bacterial-type RNA polymerase (PEP) activity and chloroplast development. The knockout of pTAC14 led to the blockage of thylakoid formation in Arabidopsis (Arabidopsis thaliana), and ptac14 was seedling lethal. Sequence and transcriptional analysis showed that pTAC14 encodes a specific protein in plants that is located in the chloroplast associated with the thylakoid and that its expression depends on light. In addition, the transcript levels of all investigated PEP-dependent genes were clearly reduced in the ptac14-1 mutants, while the accumulation of nucleus-encoded phage-type RNA polymerase-dependent transcripts was increased, indicating an important role of pTAC14 in maintaining PEP activity. pTAC14 was found to interact with pTAC12/HEMERA, another component of TACs that is involved in phytochrome signaling. The data suggest that pTAC14 is essential for proper chloroplast development, most likely by affecting PEP activity and regulating PEP-dependent plastid gene transcription in Arabidopsis together with pTAC12.
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Liere K, Weihe A, Börner T. The transcription machineries of plant mitochondria and chloroplasts: Composition, function, and regulation. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:1345-60. [PMID: 21316793 DOI: 10.1016/j.jplph.2011.01.005] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Revised: 01/07/2011] [Accepted: 01/10/2011] [Indexed: 05/04/2023]
Abstract
Although genomes of mitochondria and plastids are very small compared to those of their bacterial ancestors, the transcription machineries of these organelles are of surprising complexity. With respect to the number of different RNA polymerases per organelle, the extremes are represented on one hand by chloroplasts of eudicots which use one bacterial-type RNA polymerase and two phage-type RNA polymerases to transcribe their genes, and on the other hand by Physcomitrella possessing three mitochondrial RNA polymerases of the phage type. Transcription of genes/operons is often driven by multiple promoters in both organelles. This review describes the principle components of the transcription machineries (RNA polymerases, transcription factors, promoters) and the division of labor between the different RNA polymerases. While regulation of transcription in mitochondria seems to be only of limited importance, the plastid genes of higher plants respond to exogenous and endogenous cues rather individually by altering their transcriptional activities.
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Affiliation(s)
- Karsten Liere
- Institut für Biologie/Genetik, Humboldt-Universität zu Berlin, Chausseestrasse 117, Berlin, Germany
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29
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Matsushima R, Tang LY, Zhang L, Yamada H, Twell D, Sakamoto W. A conserved, Mg²+-dependent exonuclease degrades organelle DNA during Arabidopsis pollen development. THE PLANT CELL 2011; 23:1608-24. [PMID: 21521697 PMCID: PMC3101548 DOI: 10.1105/tpc.111.084012] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 04/01/2011] [Accepted: 04/11/2011] [Indexed: 05/18/2023]
Abstract
In plant cells, mitochondria and plastids contain their own genomes derived from the ancestral bacteria endosymbiont. Despite their limited genetic capacity, these multicopy organelle genomes account for a substantial fraction of total cellular DNA, raising the question of whether organelle DNA quantity is controlled spatially or temporally. In this study, we genetically dissected the organelle DNA decrease in pollen, a phenomenon that appears to be common in most angiosperm species. By staining mature pollen grains with fluorescent DNA dye, we screened Arabidopsis thaliana for mutants in which extrachromosomal DNAs had accumulated. Such a recessive mutant, termed defective in pollen organelle DNA degradation1 (dpd1), showing elevated levels of DNAs in both plastids and mitochondria, was isolated and characterized. DPD1 encodes a protein belonging to the exonuclease family, whose homologs appear to be found in angiosperms. Indeed, DPD1 has Mg²⁺-dependent exonuclease activity when expressed as a fusion protein and when assayed in vitro and is highly active in developing pollen. Consistent with the dpd phenotype, DPD1 is dual-targeted to plastids and mitochondria. Therefore, we provide evidence of active organelle DNA degradation in the angiosperm male gametophyte, primarily independent of maternal inheritance; the biological function of organellar DNA degradation in pollen is currently unclear.
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Affiliation(s)
- Ryo Matsushima
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan
| | - Lay Yin Tang
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan
| | - Lingang Zhang
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan
| | - Hiroshi Yamada
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan
| | - David Twell
- Department of Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - Wataru Sakamoto
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan
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Sato S. The apicomplexan plastid and its evolution. Cell Mol Life Sci 2011; 68:1285-96. [PMID: 21380560 PMCID: PMC3064897 DOI: 10.1007/s00018-011-0646-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 02/15/2011] [Accepted: 02/15/2011] [Indexed: 11/24/2022]
Abstract
Protistan species belonging to the phylum Apicomplexa have a non-photosynthetic secondary plastid-the apicoplast. Although its tiny genome and even the entire nuclear genome has been sequenced for several organisms bearing the organelle, the reason for its existence remains largely obscure. Some of the functions of the apicoplast, including housekeeping ones, are significantly different from those of other plastids, possibly due to the organelle's unique symbiotic origin.
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Affiliation(s)
- Shigeharu Sato
- Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, UK.
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DNA repair in organelles: Pathways, organization, regulation, relevance in disease and aging. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:186-200. [DOI: 10.1016/j.bbamcr.2010.10.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 10/01/2010] [Accepted: 10/05/2010] [Indexed: 12/20/2022]
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Newell CA, Gray JC. Binding of lac repressor-GFP fusion protein to lac operator sites inserted in the tobacco chloroplast genome examined by chromatin immunoprecipitation. Nucleic Acids Res 2010; 38:e145. [PMID: 20484380 PMCID: PMC2919732 DOI: 10.1093/nar/gkq413] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 04/29/2010] [Accepted: 05/04/2010] [Indexed: 11/12/2022] Open
Abstract
Chromatin immunoprecipitation (ChIP) has been used to detect binding of DNA-binding proteins to sites in nuclear and mitochondrial genomes. Here, we describe a method for detecting protein-binding sites on chloroplast DNA, using modifications to the nuclear ChIP procedures. The method was developed using the lac operator (lacO)/lac repressor (LacI) system from Escherichia coli. The lacO sequences were integrated into a single site between the rbcL and accD genes in tobacco plastid DNA and homoplasmic transplastomic plants were crossed with transgenic tobacco plants expressing a nuclear-encoded plastid-targeted GFP-LacI fusion protein. In the progeny, the GFP-LacI fusion protein could be visualized in living tissues using confocal microscopy, and was found to co-localize with plastid nucleoids. Isolated chloroplasts from the lacO/GFP-LacI plants were lysed, treated with micrococcal nuclease to digest the DNA to fragments of approximately 600 bp and incubated with antibodies to GFP and protein A-Sepharose. PCR analysis on DNA extracted from the immunoprecipitate demonstrated IPTG (isopropylthiogalactoside)-sensitive binding of GFP-LacI to lacO. Binding of GFP-LacI to endogenous sites in plastid DNA showing sequence similarity to lacO was also detected, but required reversible cross-linking with formaldehyde. This may provide a general method for the detection of binding sites on plastid DNA for specific proteins.
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Affiliation(s)
| | - John C. Gray
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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Olinares PDB, Ponnala L, van Wijk KJ. Megadalton complexes in the chloroplast stroma of Arabidopsis thaliana characterized by size exclusion chromatography, mass spectrometry, and hierarchical clustering. Mol Cell Proteomics 2010; 9:1594-615. [PMID: 20423899 DOI: 10.1074/mcp.m000038-mcp201] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
To characterize MDa-sized macromolecular chloroplast stroma protein assemblies and to extend coverage of the chloroplast stroma proteome, we fractionated soluble chloroplast stroma in the non-denatured state by size exclusion chromatography with a size separation range up to approximately 5 MDa. To maximize protein complex stability and resolution of megadalton complexes, ionic strength and composition were optimized. Subsequent high accuracy tandem mass spectrometry analysis (LTQ-Orbitrap) identified 1081 proteins across the complete native mass range. Protein complexes and assembly states above 0.8 MDa were resolved using hierarchical clustering, and protein heat maps were generated from normalized protein spectral counts for each of the size exclusion chromatography fractions; this complemented previous analysis of stromal complexes up to 0.8 MDa (Peltier, J. B., Cai, Y., Sun, Q., Zabrouskov, V., Giacomelli, L., Rudella, A., Ytterberg, A. J., Rutschow, H., and van Wijk, K. J. (2006) The oligomeric stromal proteome of Arabidopsis thaliana chloroplasts. Mol. Cell. Proteomics 5, 114-133). This combined experimental and bioinformatics analyses resolved chloroplast ribosomes in different assembly and functional states (e.g. 30, 50, and 70 S), which enabled the identification of plastid homologues of prokaryotic ribosome assembly factors as well as proteins involved in co-translational modifications, targeting, and folding. The roles of these ribosome-associating proteins will be discussed. Known RNA splice factors (e.g. CAF1/WTF1/RNC1) as well as uncharacterized proteins with RNA-binding domains (pentatricopeptide repeat, RNA recognition motif, and chloroplast ribosome maturation), RNases, and DEAD box helicases were found in various sized complexes. Chloroplast DNA (>3 MDa) was found in association with the complete heteromeric plastid-encoded DNA polymerase complex, and a dozen other DNA-binding proteins, e.g. DNA gyrase, topoisomerase, and various DNA repair enzymes. The heteromeric >or=5-MDa pyruvate dehydrogenase complex and the 0.8-1-MDa acetyl-CoA carboxylase complex associated with uncharacterized biotin carboxyl carrier domain proteins constitute the entry point to fatty acid metabolism in leaves; we suggest that their large size relates to the need for metabolic channeling. Protein annotations and identification data are available through the Plant Proteomics Database, and mass spectrometry data are available through Proteomics Identifications database.
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Spelbrink JN. Functional organization of mammalian mitochondrial DNA in nucleoids: history, recent developments, and future challenges. IUBMB Life 2010; 62:19-32. [PMID: 20014006 DOI: 10.1002/iub.282] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Various proteins involved in replication, repair, and the structural organization of mitochondrial DNA (mtDNA) have been characterized in detail over the past 25 or so years. In addition, in recent years, many proteins were identified with a role in the dynamics of the mitochondrial network. Using advanced imaging and an increasing number of cytological techniques, we have begun to realize that an important aspect to mtDNA maintenance, in both health and disease, is its organization within the dynamic mitochondrial network in discrete protein-DNA complexes usually termed nucleoids. Here, I review recent developments in the study of nucleoid dynamics and proteins. I will discuss the implications of the organization of mtDNA in nucleoids in light of DNA replication, repair, gene expression, segregation, and inheritance.
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Affiliation(s)
- Johannes N Spelbrink
- FinMIT Centre of Excellence, Institute of Medical Technology and Tampere University Hospital, University of Tampere, Tampere 33014 TAY, Finland.
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Sakamoto W, Uno Y, Zhang Q, Miura E, Kato Y. Arrested differentiation of proplastids into chloroplasts in variegated leaves characterized by plastid ultrastructure and nucleoid morphology. PLANT & CELL PHYSIOLOGY 2009; 50:2069-2083. [PMID: 19755395 DOI: 10.1093/pcp/pcp127] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Leaf variegation is seen in many ornamental plants and is often caused by a cell-lineage type formation of white sectors lacking functional chloroplasts. A mutant showing such leaf variegation is viable and is therefore suitable for studying chloroplast development. In this study, the formation of white sectors was temporally investigated in the Arabidopsis leaf-variegated mutant var2. Green sectors were found to emerge from white sectors after the formation of the first true leaf. Transmission electron microscopic examination of plastid ultrastructures confirmed that the peripheral zone in the var2 shoot meristem contained proplastids but lacked developing chloroplasts that were normally detected in wild type. These data suggest that chloroplast development proceeds very slowly in var2 variegated leaves. A notable feature in var2 is that the plastids in white sectors contain remarkable globular vacuolated membranes and prolamellar body-like structures. Although defective plastids were hardly observed in shoot meristems, they began to accumulate during early leaf development. Consistent with these observations, large plastid nucleoids detected in white sectors by DNA-specific fluorescent dyes were characteristic of those found in proplastids and were clearly distinguished from those in chloroplasts. These results strongly imply that in white sectors, differentiation of plastids into chloroplasts is arrested at the early stage of thylakoid development. Interestingly, large plastid nucleoids were detected in variegated sectors from species other than Arabidopsis. Thus, plastids in variegated leaves appear to share a common feature and represent a novel plastid type.
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Affiliation(s)
- Wataru Sakamoto
- Research Institute for Bioresources, Okayama University, Kurashiki, Okayama, 710-0046, Japan
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36
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Sasaki N, Hirai M, Maeda K, Yui R, Itoh K, Namiki S, Morita T, Hata M, Murakami-Murofushi K, Matsuoka H, Kita K, Sato S. The Plasmodium HU homolog, which binds the plastid DNA sequence-independent manner, is essential for the parasite's survival. FEBS Lett 2009; 583:1446-50. [PMID: 19358847 DOI: 10.1016/j.febslet.2009.03.071] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 03/26/2009] [Accepted: 03/31/2009] [Indexed: 10/20/2022]
Abstract
The nuclear genome of the human malaria parasite Plasmodium falciparum encodes a homolog of the bacterial HU protein (PfHU). In this study, we characterised PfHU's physiological function. PfHU, which is targeted exclusively to the parasite's plastid, bound its natural target--the plastid DNA--sequence-independently and complemented lack of HU in Escherichia coli. The HU gene could not be knocked-out from the genome of Plasmodium berghei, implying that HU is important for the parasite's survival. As the human cell lacks the HU homolog, PfHU is a potential target for drugs to control malaria.
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Affiliation(s)
- Narie Sasaki
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
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Prikryl J, Watkins KP, Friso G, van Wijk KJ, Barkan A. A member of the Whirly family is a multifunctional RNA- and DNA-binding protein that is essential for chloroplast biogenesis. Nucleic Acids Res 2008; 36:5152-65. [PMID: 18676978 PMCID: PMC2532728 DOI: 10.1093/nar/gkn492] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 07/14/2008] [Accepted: 07/16/2008] [Indexed: 12/01/2022] Open
Abstract
'Whirly' proteins comprise a plant-specific protein family whose members have been described as DNA-binding proteins that influence nuclear transcription and telomere maintenance, and that associate with nucleoids in chloroplasts and mitochondria. We identified the maize WHY1 ortholog among proteins that coimmunoprecipitate with CRS1, which promotes the splicing of the chloroplast atpF group II intron. ZmWHY1 localizes to the chloroplast stroma and to the thylakoid membrane, to which it is tethered by DNA. Genome-wide coimmunoprecipitation assays showed that ZmWHY1 in chloroplast extract is associated with DNA from throughout the plastid genome and with a subset of plastid RNAs that includes atpF transcripts. Furthermore, ZmWHY1 binds both RNA and DNA in vitro. A severe ZmWhy1 mutant allele conditions albino seedlings lacking plastid ribosomes; these exhibit the altered plastid RNA profile characteristic of ribosome-less plastids. Hypomorphic ZmWhy1 mutants exhibit reduced atpF intron splicing and a reduced content of plastid ribosomes; aberrant 23S rRNA metabolism in these mutants suggests that a defect in the biogenesis of the large ribosomal subunit underlies the ribosome deficiency. However, these mutants contain near normal levels of chloroplast DNA and RNAs, suggesting that ZmWHY1 is not directly required for either DNA replication or for global plastid transcription.
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Affiliation(s)
- Jana Prikryl
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97405 and Department of Plant Biology, Cornell University, Ithaca, NY 14853, USA
| | - Kenneth P. Watkins
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97405 and Department of Plant Biology, Cornell University, Ithaca, NY 14853, USA
| | - Giulia Friso
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97405 and Department of Plant Biology, Cornell University, Ithaca, NY 14853, USA
| | - Klaas J. van Wijk
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97405 and Department of Plant Biology, Cornell University, Ithaca, NY 14853, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97405 and Department of Plant Biology, Cornell University, Ithaca, NY 14853, USA
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Ram EVSR, Naik R, Ganguli M, Habib S. DNA organization by the apicoplast-targeted bacterial histone-like protein of Plasmodium falciparum. Nucleic Acids Res 2008; 36:5061-73. [PMID: 18663012 PMCID: PMC2528193 DOI: 10.1093/nar/gkn483] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Apicomplexans, including the pathogens Plasmodium and Toxoplasma, carry a nonphotosynthetic plastid of secondary endosymbiotic origin called the apicoplast. The P. falciparum apicoplast contains a 35 kb, circular DNA genome with limited coding capacity that lacks genes encoding proteins for DNA organization and replication. We report identification of a nuclear-encoded bacterial histone-like protein (PfHU) involved in DNA compaction in the apicoplast. PfHU is associated with apicoplast DNA and is expressed throughout the parasite's intra-erythocytic cycle. The protein binds DNA in a sequence nonspecific manner with a minimum binding site length of ∼27 bp and a Kd of ∼63 nM and displays a preference for supercoiled DNA. PfHU is capable of condensing Escherichia coli nucleoids in vivo indicating its role in DNA compaction. The unique 42 aa C-terminal extension of PfHU influences its DNA condensation properties. In contrast to bacterial HUs that bend DNA, PfHU promotes concatenation of linear DNA and inhibits DNA circularization. Atomic Force Microscopic study of PfHU–DNA complexes shows protein concentration-dependent DNA stiffening, intermolecular bundling and formation of DNA bridges followed by assembly of condensed DNA networks. Our results provide the first functional characterization of an apicomplexan HU protein and provide additional evidence for red algal ancestry of the apicoplast.
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Affiliation(s)
- E V S Raghu Ram
- Division of Molecular and Structural Biology, Central Drug Research Institute, Lucknow-226 001, India
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Majeran W, Zybailov B, Ytterberg AJ, Dunsmore J, Sun Q, van Wijk KJ. Consequences of C4 differentiation for chloroplast membrane proteomes in maize mesophyll and bundle sheath cells. Mol Cell Proteomics 2008; 7:1609-38. [PMID: 18453340 DOI: 10.1074/mcp.m800016-mcp200] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chloroplasts of maize leaves differentiate into specific bundle sheath (BS) and mesophyll (M) types to accommodate C(4) photosynthesis. Chloroplasts contain thylakoid and envelope membranes that contain the photosynthetic machineries and transporters but also proteins involved in e.g. protein homeostasis. These chloroplast membranes must be specialized within each cell type to accommodate C(4) photosynthesis and regulate metabolic fluxes and activities. This quantitative study determined the differentiated state of BS and M chloroplast thylakoid and envelope membrane proteomes and their oligomeric states using innovative gel-based and mass spectrometry-based protein quantifications. This included native gels, iTRAQ, and label-free quantification using an LTQ-Orbitrap. Subunits of Photosystems I and II, the cytochrome b(6)f, and ATP synthase complexes showed average BS/M accumulation ratios of 1.6, 0.45, 1.0, and 1.33, respectively, whereas ratios for the light-harvesting complex I and II families were 1.72 and 0.68, respectively. A 1000-kDa BS-specific NAD(P)H dehydrogenase complex with associated proteins of unknown function containing more than 15 proteins was observed; we speculate that this novel complex possibly functions in inorganic carbon concentration when carboxylation rates by ribulose-bisphosphate carboxylase/oxygenase are lower than decarboxylation rates by malic enzyme. Differential accumulation of thylakoid proteases (Egy and DegP), state transition kinases (STN7,8), and Photosystem I and II assembly factors was observed, suggesting that cell-specific photosynthetic electron transport depends on post-translational regulatory mechanisms. BS/M ratios for inner envelope transporters phosphoenolpyruvate/P(i) translocator, Dit1, Dit2, and Mex1 were determined and reflect metabolic fluxes in carbon metabolism. A wide variety of hundreds of other proteins showed differential BS/M accumulation. Mass spectral information and functional annotations are available through the Plant Proteome Database. These data are integrated with previous data, resulting in a model for C(4) photosynthesis, thereby providing new rationales for metabolic engineering of C(4) pathways and targeted analysis of genetic networks that coordinate C(4) differentiation.
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Affiliation(s)
- Wojciech Majeran
- Department of Plant Biology, Cornell University, Ithaca, New York 14853, USA
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40
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Moriyama T, Terasawa K, Fujiwara M, Sato N. Purification and characterization of organellar DNA polymerases in the red alga Cyanidioschyzon merolae. FEBS J 2008; 275:2899-918. [PMID: 18430024 DOI: 10.1111/j.1742-4658.2008.06426.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA polymerase gamma, a mitochondrial replication enzyme of yeasts and animals, is not present in photosynthetic eukaryotes. Recently, DNA polymerases with distant homology to bacterial DNA polymerase I were reported in rice, Arabidopsis, and tobacco, and they were localized to both plastids and mitochondria. We call them plant organellar DNA polymerases (POPs). However, POPs have never been purified in the native form from plant tissues. The unicellular thermotrophic red alga Cyanidioschyzon merolae contains two genes encoding proteins related to Escherichia coli DNA polymerase I (PolA and PolB). Phylogenetic analysis revealed that PolB is an ortholog of POPs. Nonphotosynthetic eukaryotes also have POPs, which suggested that POPs have an ancient origin before eukaryotic photosynthesis. PolA is a homolog of bacterial DNA polymerase I and is distinct from POPs. PolB was purified from the C. merolae cells by a series of column chromatography steps. Recombinant protein of PolA was also purified. Sensitivity to inhibitors of DNA synthesis was different in PolA, PolB, and E. coli DNA polymerase I. Immunoblot analysis and targeting studies with green fluorescent protein fusion proteins demonstrated that PolA was localized in the plastids, whereas PolB was present in both plastids and mitochondria. The expression of PolB was regulated by the cell cycle. The available results suggest that PolB is involved in the replication of plastids and mitochondria.
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Affiliation(s)
- Takashi Moriyama
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Japan
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The plastid sigma factor SIG5 is involved in the diurnal regulation of the chloroplast genepsbDin the mossPhyscomitrella patens. FEBS Lett 2008; 582:405-9. [DOI: 10.1016/j.febslet.2007.12.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Revised: 12/01/2007] [Accepted: 12/19/2007] [Indexed: 11/22/2022]
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42
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Sakamoto W, Miyagishima SY, Jarvis P. Chloroplast biogenesis: control of plastid development, protein import, division and inheritance. THE ARABIDOPSIS BOOK 2008; 6:e0110. [PMID: 22303235 PMCID: PMC3243408 DOI: 10.1199/tab.0110] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The chloroplast is a multi-copy cellular organelle that not only performs photosynthesis but also synthesizes amino acids, lipids and phytohormones. The plastid also responds to environmental stimuli such as gravitropism. Biogenesis of chloroplasts is initiated from proplastids in shoot meristems, and involves a series of important events. In the last decade, considerable progress has been made towards understanding various aspects of chloroplast biogenesis at the molecular level, via studies in model systems such as Arabidopsis. This review focuses on two important aspects of chloroplast biogenesis, synthesis/assembly and division/transmission. Chloroplasts originated through endosymbiosis from an ancestor of extant cyanobacteria, and thus contain their own genomes. DNA in chloroplasts is organized into complexes with proteins, and these are called nucleoids. The synthesis of chloroplast proteins is regulated at various steps. However, a majority of proteins are synthesized in the cytosol, and their proper import into chloroplast compartments is a prerequisite for chloroplast development. Fundamental aspects of plastid gene expression/regulation and chloroplast protein transport are described, together with recent proteome analyses of the organelle. Chloroplasts are not de novo synthesized, but instead are propagated from pre-existing plastids. In addition, plastids are transmitted from generation to generation with a unique mode of inheritance. Our current knowledge on the division machinery and the inheritance of plastids is described.
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Affiliation(s)
- Wataru Sakamoto
- Research Institute for Bioresources, Okayama University, Kurashiki, Okayama 710-0046, Japan
- Address correspondence to
| | | | - Paul Jarvis
- Department of Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
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Ono Y, Sakai A, Takechi K, Takio S, Takusagawa M, Takano H. NtPolI-like1 and NtPolI-like2, bacterial DNA polymerase I homologs isolated from BY-2 cultured tobacco cells, encode DNA polymerases engaged in DNA replication in both plastids and mitochondria. PLANT & CELL PHYSIOLOGY 2007; 48:1679-92. [PMID: 17942449 DOI: 10.1093/pcp/pcm140] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Two cDNAs encoding homologs of bacterial DNA polymerase I were isolated from cultured tobacco (Nicotiana tabacum) BY-2 cells, and the corresponding genes were named NtPolI-like1 and NtPolI-like2. High sequence similarity suggested that they are orthologous genes each derived from respective parental species of N. tabacum, an allotetraploid plant. Each of the NtPolI-like1/2 gene products had a putative transit peptide for plastid localization at the N-terminus, followed by a 3'-5' exonuclease domain in the internal region, and a DNA polymerase domain in the C-terminal region. Among family A DNA polymerases, NtPolI-like proteins formed, together with other plant DNA polymerase I homologs, a phylogenetic group distinct from mitochondrial DNA polymerase gamma in animals and fungi, as well as eukaryotic cell nuclear-localized repair enzymes. In contrast to computer predictions, experiments with green fluorescent protein (GFP) fusion protein and Western blotting analysis suggested dual targeting of the gene products to both plastids and mitochondria. The recombinant NtPolI-like2 protein exhibited DNA polymerase activity in vitro. Their biochemical character roughly coincided with those of the 116 kDa DNA polymerases found in the plastid and mitochondrial nuclei (nucleoids) isolated from BY-2 cells. Pre-treatment of the organelle nuclear extracts with anti-NtPolI-like antibody removed most of the DNA polymerase activity. Reverse transcription-PCR (RT-PCR) and Western blotting analyses demonstrated transient activation of NtPolI-like gene expression in the initial phase of cell proliferation, exactly when the 116 kDa DNA polymerases in the isolated organelle nuclei were activated and preferential synthesis of organelle DNAs occurred. Taken together, our results suggest that NtPolI-like1/2 genes encode DNA polymerases engaged in DNA replication in both plastids and mitochondria.
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Affiliation(s)
- Yuriko Ono
- Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
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Sato N, Moriyama T. Genomic and biochemical analysis of lipid biosynthesis in the unicellular rhodophyte Cyanidioschyzon merolae: lack of a plastidic desaturation pathway results in the coupled pathway of galactolipid synthesis. EUKARYOTIC CELL 2007; 6:1006-17. [PMID: 17416897 PMCID: PMC1951526 DOI: 10.1128/ec.00393-06] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Accepted: 03/20/2007] [Indexed: 11/20/2022]
Abstract
The acyl lipids making up the plastid membranes in plants and algae are highly enriched in polyunsaturated fatty acids and are synthesized by two distinct pathways, known as the prokaryotic and eukaryotic pathways, which are located within the plastids and the endoplasmic reticulum, respectively. Here we report the results of biochemical as well as genomic analyses of lipids and fatty acids in the unicellular rhodophyte Cyanidioschyzon merolae. All of the glycerolipids usually found in photosynthetic algae were found, such as mono- and digalactosyl diacylglycerol, sulfolipid, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol. However, the fatty acid composition was extremely simple. Only palmitic, stearic, oleic, and linoleic acids were found as major acids. In addition, 3-trans-hexadecanoic acid was found as a very minor component in phosphatidylglycerol. Unlike the case for most other photosynthetic eukaryotes, polyenoic fatty acids having three or more double bonds were not detected. These results suggest that polyunsaturated fatty acids are not necessary for photosynthesis in eukaryotes. Genomic analysis suggested that C. merolae lacks acyl lipid desaturases of cyanobacterial origin as well as stearoyl acyl carrier protein desaturase, both of which are major desaturases in plants and green algae. The results of labeling experiments with radioactive acetate showed that the desaturation leading to linoleic acid synthesis occurs on phosphatidylcholine located outside the plastids. Monogalactosyl diacylglycerol is therefore synthesized by the coupled pathway, using plastid-derived palmitic acid and endoplasmic reticulum-derived linoleic acid. These results highlight essential differences in lipid biosynthetic pathways between the red algae and the green lineage, which includes plants and green algae.
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Affiliation(s)
- Naoki Sato
- 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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Sekine K, Fujiwara M, Nakayama M, Takao T, Hase T, Sato N. DNA binding and partial nucleoid localization of the chloroplast stromal enzyme ferredoxin:sulfite reductase. FEBS J 2007; 274:2054-69. [PMID: 17371503 DOI: 10.1111/j.1742-4658.2007.05748.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Sulfite reductase (SiR) is an important enzyme catalyzing the reduction of sulfite to sulfide during sulfur assimilation in plants. This enzyme is localized in plastids, including chloroplasts, and uses ferredoxin as an electron donor. Ferredoxin-dependent SiR has been found in isolated chloroplast nucleoids, but its localization in vivo or in intact plastids has not been examined. Here, we report the DNA-binding properties of SiRs from pea (PsSiR) and maize (ZmSiR) using an enzymatically active holoenzyme with prosthetic groups. PsSiR binds to both double-stranded and single-stranded DNA without significant sequence specificity. DNA binding did not affect the enzymatic activity of PsSiR, suggesting that ferredoxin and sulfite are accessible to SiR molecules within the nucleoids. Comparison of PsSiR and ZmSiR suggests that ZmSiR does indeed have DNA-binding activity, as was reported previously, but the DNA affinity and DNA-compacting ability are higher in PsSiR than in ZmSiR. The tight compaction of nucleoids by PsSiR led to severe repression of transcription activity in pea nucleoids. Indirect immunofluorescence microscopy showed that the majority of SiR molecules colocalized with nucleoids in pea chloroplasts, whereas no particular localization to nucleoids was detected in maize chloroplasts. These results suggest that SiR plays an essential role in compacting nucleoids in plastids, but that the extent of association of SiR with nucleoids varies among plant species.
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Affiliation(s)
- Kohsuke Sekine
- Department of Molecular Biology, Faculty of Science, Saitama University, Japan
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DNA replication, recombination, and repair in plastids. CELL AND MOLECULAR BIOLOGY OF PLASTIDS 2007. [DOI: 10.1007/4735_2007_0231] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Sato N. Origin and Evolution of Plastids: Genomic View on the Unification and Diversity of Plastids. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2007. [DOI: 10.1007/978-1-4020-4061-0_4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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48
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Chan YH, Kwok ACM, Tsang JSH, Wong JTY. Alveolata histone-like proteins have different evolutionary origins. J Evol Biol 2006; 19:1717-21. [PMID: 16911001 DOI: 10.1111/j.1420-9101.2006.01089.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Prokaryotic histone-like proteins (Hlps) are abundant proteins found in bacterial and plastid nucleoids. Hlps are also found in the eukaryotic dinoflagellates and the apicomplexans, two major lineages of the Alveolata. It may be expected that Hlps of both groups were derived from the same ancestral Alveolates. However, our phylogenetic analyses suggest different origins for the dinoflagellate and the apicomplexan Hlps. The apicomplexan Hlps are affiliated with the cyanobacteria and probably originated from Hlps of the plastid genome. The dinoflagellate Hlps and the proteobacterial long Hlps form a clade that branch off from the node with the proteobacterial short Hlps.
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Affiliation(s)
- Y H Chan
- Department of Biology, Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, People's Republic of China
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Terasawa K, Sato N. Occurrence and characterization of PEND proteins in angiosperms. JOURNAL OF PLANT RESEARCH 2005; 118:111-9. [PMID: 15834640 DOI: 10.1007/s10265-005-0200-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2004] [Accepted: 01/31/2005] [Indexed: 05/04/2023]
Abstract
The PEND protein is a DNA-binding protein in the inner envelope membrane of the developing chloroplast. It consists of a short pre-sequence, an N-terminal DNA-binding domain (cbZIP), a central repeat domain, and a C-terminal transmembrane domain. PEND homologs have been detected in various angiosperms, including Arabidopsis thaliana, Brassica napus, Medicago truncatula, cucumber and cherry. Monocot homologs have also been detected in barley and rice, but sequence conservation was low in monocots. PEND-related sequences have not been detected in non-flowering plants and algae. Green fluorescent protein fusions consisting of the N-terminal as well as full-length PEND homologs in A. thaliana and B. napus were targeted to chloroplasts, and localized to nucleoids and chloroplast periphery, respectively. Immunoblot analysis suggested that crucifer homologs were present in chloroplasts probably as a dimer, as in the case of pea. These results suggest that PEND protein is present in angiosperms, and the homologs in crucifers are functionally analogous to the PEND protein in pea.
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Affiliation(s)
- Kimihiro Terasawa
- Department of Molecular Biology, Faculty of Science, Saitama University, Sakura-ku, Saitama, 338-8570, Japan
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Terasawa K, Sato N. Visualization of plastid nucleoids in situ using the PEND-GFP fusion protein. PLANT & CELL PHYSIOLOGY 2005; 46:649-60. [PMID: 15746158 DOI: 10.1093/pcp/pci070] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Plastid DNA is a circular molecule of 120-150 kbp, which is organized into a protein-DNA complex called a nucleoid. Although various plastids other than chloroplasts exist, such as etioplasts, amyloplasts and chromoplasts, it is not easy to observe plastid nucleoids within the cells of many non-green tissues. The PEND (plastid envelope DNA-binding) protein is a DNA-binding protein in the inner envelope membrane of developing chloroplasts, and a DNA-binding domain called cbZIP is present at its N-terminus. We made various PEND-green fluorescent protein (GFP) fusion proteins using the cbZIP domains from various plants, and found that they were localized in the chloroplast nucleoids in transient expression in leaf protoplasts. In stable transformants of Arabidopsis thaliana, PEND-GFP fusion proteins were also localized in the nucleoids of various plastids. We have succeeded in visualizing plastid nucleoids in various intact tissues using this stable transformant. This technique is useful in root, flower and pollen, in which it had been difficult to observe plastid nucleoids. The relative arrangement of nucleoids within a chloroplast was kept unchanged when the chloroplast moved within a cell. During the division of plastid, nucleoids formed a network structure, which made possible equal partition of nucleoids.
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Affiliation(s)
- Kimihiro Terasawa
- Department of Molecular Biology, Faculty of Science, Saitama University, Sakura-ku, Saitama, 338-8570 Japan
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