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Harada R, Hirakawa Y, Yabuki A, Kim E, Yazaki E, Kamikawa R, Nakano K, Eliáš M, Inagaki Y. Encyclopedia of Family A DNA Polymerases Localized in Organelles: Evolutionary Contribution of Bacteria Including the Proto-Mitochondrion. Mol Biol Evol 2024; 41:msae014. [PMID: 38271287 PMCID: PMC10877234 DOI: 10.1093/molbev/msae014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/12/2024] [Accepted: 01/19/2024] [Indexed: 01/27/2024] Open
Abstract
DNA polymerases synthesize DNA from deoxyribonucleotides in a semiconservative manner and serve as the core of DNA replication and repair machinery. In eukaryotic cells, there are 2 genome-containing organelles, mitochondria, and plastids, which were derived from an alphaproteobacterium and a cyanobacterium, respectively. Except for rare cases of genome-lacking mitochondria and plastids, both organelles must be served by nucleus-encoded DNA polymerases that localize and work in them to maintain their genomes. The evolution of organellar DNA polymerases has yet to be fully understood because of 2 unsettled issues. First, the diversity of organellar DNA polymerases has not been elucidated in the full spectrum of eukaryotes. Second, it is unclear when the DNA polymerases that were used originally in the endosymbiotic bacteria giving rise to mitochondria and plastids were discarded, as the organellar DNA polymerases known to date show no phylogenetic affinity to those of the extant alphaproteobacteria or cyanobacteria. In this study, we identified from diverse eukaryotes 134 family A DNA polymerase sequences, which were classified into 10 novel types, and explored their evolutionary origins. The subcellular localizations of selected DNA polymerases were further examined experimentally. The results presented here suggest that the diversity of organellar DNA polymerases has been shaped by multiple transfers of the PolI gene from phylogenetically broad bacteria, and their occurrence in eukaryotes was additionally impacted by secondary plastid endosymbioses. Finally, we propose that the last eukaryotic common ancestor may have possessed 2 mitochondrial DNA polymerases, POP, and a candidate of the direct descendant of the proto-mitochondrial DNA polymerase I, rdxPolA, identified in this study.
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Affiliation(s)
- Ryo Harada
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yoshihisa Hirakawa
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Akinori Yabuki
- Deep-Sea Biodiversity Research Group, Research Institute for Global Change (RIGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Eunsoo Kim
- Division of EcoScience, Ewha Womans University, Seoul, South Korea
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY, USA
| | - Euki Yazaki
- Research Center for Advanced Analysis, National Agriculture and Food Research Organization, Tsukuba, Japan
- Interdisciplinary Theoretical and Mathematical Sciences program (iTHEMS), RIKEN, Wako, Saitama, Japan
| | - Ryoma Kamikawa
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kentaro Nakano
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Yuji Inagaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
- Center for Computational Sciences, University of Tsukuba, Tsukuba, Japan
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González-Balderas R, Velasquez-Orta S, Felix M, Bengoechea C, Yañez Noguez I, Orta Ledesma M. Identification and effect of ozone and ultrasound pretreatments on Desmodesmus sp. and Tetradesmus obliquus proteins. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Dorrell RG, Klinger CM, Newby RJ, Butterfield ER, Richardson E, Dacks JB, Howe CJ, Nisbet ER, Bowler C. Progressive and Biased Divergent Evolution Underpins the Origin and Diversification of Peridinin Dinoflagellate Plastids. Mol Biol Evol 2016; 34:361-379. [DOI: 10.1093/molbev/msw235] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tandem repeats, high copy number and remarkable diel expression rhythm of form II RuBisCO in Prorocentrum donghaiense (Dinophyceae). PLoS One 2013; 8:e71232. [PMID: 23976999 PMCID: PMC3747160 DOI: 10.1371/journal.pone.0071232] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 06/27/2013] [Indexed: 11/24/2022] Open
Abstract
Gene structure and expression regulation of form II RuBisCO (rbcII) in dinoflagellates are still poorly understood. Here we isolated this gene (Pdrbc) and investigated its diel expression pattern in a harmful algal bloom forming dinoflagellate Prorocentrum donghaiense. We obtained cDNA sequences with triple tandem repeats of the coding unit (CU); the 5′ region has the sequence of a typical dinoflagellate plastid gene, encoding an N-terminus with two transmembrane regions separated by a plastid transit peptide. The CUs (1,455 bp except 1464 bp in last CU) are connected through a 63 bp spacer. Phylogenetic analysis showed that rbcII CUs within species formed monophyletic clusters, indicative of intraspecific gene duplication or purifying evolution. Using quantitative PCR (qPCR) we estimated 117±40 CUs of Pdrbc in the P. donghaiense genome. Although it is commonly believed that most dinoflagellate genes lack transcriptional regulation, our RT-qPCR analysis on synchronized cultures revealed remarkable diel rhythm of Pdrbc expression, showing significant correlations of transcript abundance with the timing of the dark-to-light transition and cell cycle G2M-phase. When the cultures were shifted to continuous light, Pdrbc expression remained significantly correlated with the G2M-phase. Under continuous darkness the cell cycle was arrested at the G1 phase, and the rhythm of Pdrbc transcription disappeared. Our results suggest that dinoflagellate rbcII 1) undergoes duplication or sequence purification within species, 2) is organized in tandem arrays in most species probably to facilitate efficient translation and import of the encoded enzyme, and 3) is regulated transcriptionally in a cell cycle-dependent fashion at least in some dinoflagellates.
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Hopkins JF, Spencer DF, Laboissiere S, Neilson JAD, Eveleigh RJM, Durnford DG, Gray MW, Archibald JM. Proteomics reveals plastid- and periplastid-targeted proteins in the chlorarachniophyte alga Bigelowiella natans. Genome Biol Evol 2013; 4:1391-406. [PMID: 23221610 PMCID: PMC3542566 DOI: 10.1093/gbe/evs115] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Chlorarachniophytes are unicellular marine algae with plastids (chloroplasts) of secondary endosymbiotic origin. Chlorarachniophyte cells retain the remnant nucleus (nucleomorph) and cytoplasm (periplastidial compartment, PPC) of the green algal endosymbiont from which their plastid was derived. To characterize the diversity of nucleus-encoded proteins targeted to the chlorarachniophyte plastid, nucleomorph, and PPC, we isolated plastid–nucleomorph complexes from the model chlorarachniophyte Bigelowiella natans and subjected them to high-pressure liquid chromatography-tandem mass spectrometry. Our proteomic analysis, the first of its kind for a nucleomorph-bearing alga, resulted in the identification of 324 proteins with 95% confidence. Approximately 50% of these proteins have predicted bipartite leader sequences at their amino termini. Nucleus-encoded proteins make up >90% of the proteins identified. With respect to biological function, plastid-localized light-harvesting proteins were well represented, as were proteins involved in chlorophyll biosynthesis. Phylogenetic analyses revealed that many, but by no means all, of the proteins identified in our proteomic screen are of apparent green algal ancestry, consistent with the inferred evolutionary origin of the plastid and nucleomorph in chlorarachniophytes.
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Affiliation(s)
- Julia F Hopkins
- Department of Biochemistry and Molecular Biology, Dalhousie University, Nova Scotia, Canada
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Coupled Effects of Light and Nitrogen Source on the Urea Cycle and Nitrogen Metabolism over a Diel Cycle in the Marine Diatom Thalassiosira pseudonana. Protist 2012; 163:232-51. [DOI: 10.1016/j.protis.2011.07.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 07/10/2011] [Indexed: 11/21/2022]
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Kaul T, Reddy PS, Mahanty S, Thirulogachandar V, Reddy RA, Kumar B, Sopory SK, Reddy MK. Biochemical and molecular characterization of stress-induced β-carbonic anhydrase from a C(4) plant, Pennisetum glaucum. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:601-10. [PMID: 20884079 DOI: 10.1016/j.jplph.2010.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 08/19/2010] [Accepted: 08/29/2010] [Indexed: 05/20/2023]
Abstract
Genes encoding for many β-carbonic anhydrases and their functions in various developmental processes are well established in lower plants, however, similar studies are limited in higher plants. We report the cloning and characterization of cDNA encoding for a β-carbonic anhydrase (PgCA) from Pennisetum glaucum, a C(4) crop plant. cDNA encoding 249 amino acids and its deduced amino acid sequence analysis revealed that is related to other plant β-CA family members with an over all conserved architecture of a typical β-CA protein. Phylogenetic analysis revealed that PgCA is evolutionarily very close to chloroplast β-CA isoform. Signal sequence predicting programs identify a N-terminus putative chloroplast targeting sequence. Heterologous Escherichia coli expression system was utilized to overexpress recombinant PgCA, which showed high thermostability, an alkaline pH optima and dual activity with both reversible CO(2) hydration and esterase activities. The β-CAs studied so far possessed only CO(2) hydration activity with no detectable esterase activity. Recombinant PgCA esterase activity is inhibited by standard CA inhibitors acetazolamide, methazolamide and azide. Subcellular immunostaining studies revealed a chloroplastic localization of PgCA protein. Expression of PgCA transcript is differentially up regulated in response to various abiotic stresses wherein its accumulation in Pennisetum leaves positively correlated with the intensity and duration of stress. Biochemical and transcript analyses suggest that PgCA may play a significant role in plant's adaptation to different abiotic stresses in addition to the previously recognized role of replenishing the CO(2) supply within plant cells.
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Affiliation(s)
- Tanushri Kaul
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi 110 067, India
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Hirakawa Y, Ishida KI. Internal plastid-targeting signal found in a RubisCO small subunit protein of a chlorarachniophyte alga. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 64:402-410. [PMID: 21049565 DOI: 10.1111/j.1365-313x.2010.04334.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In all plants and algae, most plastid proteins are encoded by the nuclear genome and, consequently, need to be transported into plastids across multiple membranes. In organisms with secondary plastids, which evolved by secondary endosymbioses, and are surrounded by three or four envelope membranes, precursors of nuclear-encoded plastid proteins generally have an N-terminal bipartite targeting sequence that consists of an endoplasmic reticulum (ER)-targeting signal peptide (SP) and a transit peptide-like (TPL) sequence. The bipartite targeting sequences have been demonstrated to be necessary and sufficient for targeting proteins into the plastids of many algal groups, including chlorarachniophytes. Here, we report a new type of targeting signal that is required for delivering a RubisCO small subunit (RbcS) protein into the secondary plastids of chlorarachniophyte algae. In this study, we analyzed the plastid-targeting ability of an RbcS pre-protein, using green fluorescent protein (GFP) as a reporter molecule in chlorarachniophyte cells. We demonstrate that the N-terminal bipartite targeting sequence of the RbcS pre-protein is not sufficient, and that a part of the mature protein is also necessary for plastid targeting. By deletion analyses of amino acids, we determined the approximate location of an internal plastid-targeting signal within the mature protein, which is involved in targeting the protein from the ER into the chlorarachniophyte plastids.
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Affiliation(s)
- Yoshihisa Hirakawa
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba 305-8572, Japan
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Jiroutová K, Kořený L, Bowler C, Oborník M. A gene in the process of endosymbiotic transfer. PLoS One 2010; 5:e13234. [PMID: 20949086 PMCID: PMC2950852 DOI: 10.1371/journal.pone.0013234] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 09/13/2010] [Indexed: 12/02/2022] Open
Abstract
Background The endosymbiotic birth of organelles is accompanied by massive transfer of endosymbiont genes to the eukaryotic host nucleus. In the centric diatom Thalassiosira pseudonana the Psb28 protein is encoded in the plastid genome while a second version is nuclear-encoded and possesses a bipartite N-terminal presequence necessary to target the protein into the diatom complex plastid. Thus it can represent a gene captured during endosymbiotic gene transfer. Methodology/Principal Findings To specify the origin of nuclear- and plastid-encoded Psb28 in T. pseudonana we have performed extensive phylogenetic analyses of both mentioned genes. We have also experimentally tested the intracellular location of the nuclear-encoded Psb28 protein (nuPsb28) through transformation of the diatom Phaeodactylum tricornutum with the gene in question fused to EYFP. Conclusions/Significance We show here that both versions of the psb28 gene in T. pseudonana are transcribed. We also provide experimental evidence for successful targeting of the nuPsb28 fused with EYFP to the diatom complex plastid. Extensive phylogenetic analyses demonstrate that nucleotide composition of the analyzed genes deeply influences the tree topology and that appropriate methods designed to deal with a compositional bias of the sequences and the long branch attraction artefact (LBA) need to be used to overcome this obstacle. We propose that nuclear psb28 in T. pseudonana is a duplicate of a plastid localized version, and that it has been transferred from its endosymbiont.
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Affiliation(s)
- Kateřina Jiroutová
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic and Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Luděk Kořený
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic and Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Chris Bowler
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR8197, Ecole Normale Supérieure, Paris, France
| | - Miroslav Oborník
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic and Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- * E-mail:
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Hirakawa Y, Gile GH, Ota S, Keeling PJ, Ishida KI. Characterization of periplastidal compartment-targeting signals in chlorarachniophytes. Mol Biol Evol 2010; 27:1538-45. [PMID: 20133351 DOI: 10.1093/molbev/msq038] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Secondary plastids are acquired by the engulfment and retention of eukaryotic algae, which results in an additional surrounding membrane or pair of membranes relative to the more familiar primary plastids of land plants. In most cases, the endocytosed alga loses its eukaryotic genome as it becomes integrated, but in two algal groups, the cryptophytes and chlorarachniophytes, the secondary plastids retain a vestigial nucleus in the periplastidal compartment (PPC), the remnant eukaryotic cytoplasm between the inner and the outer membrane pairs. Many essential housekeeping genes are missing from these reduced genomes, suggesting that they are now encoded in the host nucleus and their products are targeted to the PPC. One such nucleus-encoded, PPC-targeted protein, the translation elongation factor like (EFL) was recently identified in chlorarachniophytes. It bears an N-terminal-targeting sequence comprising a signal peptide and a transit peptide-like sequence (TPL) similar to the plastid-targeted proteins of chlorarachniophytes as well as a hydrophilic C-terminal extension rich in lysine and aspartic acid. Here, we characterize the function of the N- and C-terminal extensions of PPC-targeted EFL in transformed chlorarachniophyte cells. Using green fluorescent protein as a reporter molecule, we demonstrate that several negatively charged amino acids within the TPL are essential for accurate targeting to the PPC. Our findings further reveal that the C-terminal extension functions as a PPC retention signal in combination with an N-terminal plastid-targeting peptide, which suggests that plastid and PPC proteins may be sorted in the PPC.
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Affiliation(s)
- Yoshihisa Hirakawa
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
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Armbruster U, Hertle A, Makarenko E, Zühlke J, Pribil M, Dietzmann A, Schliebner I, Aseeva E, Fenino E, Scharfenberg M, Voigt C, Leister D. Chloroplast proteins without cleavable transit peptides: rare exceptions or a major constituent of the chloroplast proteome? MOLECULAR PLANT 2009; 2:1325-35. [PMID: 19995733 DOI: 10.1093/mp/ssp082] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Most chloroplast proteins (cp proteins) are nucleus-encoded, synthesized on cytosolic ribosomes as precursor proteins containing a presequence (cTP), and post-translationally imported via the Tic/Toc complex into the organelle, where the cTP is removed. Only a few unambiguous instances of cp proteins that do not require cTPs (non-canonical cp proteins) have been reported so far. However, the survey of data from large-scale proteomic studies presented here suggests that the fraction of such proteins in the total cp proteome might be as large as approximately 30%. To explore this discrepancy, we chose a representative set of 28 putative non-canonical cp proteins, and used in vitro import and Red Fluorescent Protein (RFP)-fusion assays to determine their sub-cellular destinations. Four proteins, including embryo defective 1211, glycolate oxidase 2, protein disulfide isomerase-like protein (PDII), and a putative glutathione S-transferase, could be unambiguously assigned to the chloroplast. Several others ('potential cp proteins') were found to be imported into chloroplasts in vitro, but failed to localize to the organelle when RFP was fused to their C-terminal ends. Extrapolations suggest that the fraction of cp proteins that enter the inner compartments of the organelle, although they lack a cTP, might be as large as 11.4% of the total cp proteome. Our data also support the idea that cytosolic proteins that associate with the cp outer membrane might account for false positive cp proteins obtained in earlier studies.
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Affiliation(s)
- Ute Armbruster
- Lehrstuhl für Botanik, Department Biologie I, Ludwig-Maximilians-Universität München, Menzinger Str. 67, D-80638 München, Germany
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On the origin of chloroplasts, import mechanisms of chloroplast-targeted proteins, and loss of photosynthetic ability — review. Folia Microbiol (Praha) 2009; 54:303-21. [DOI: 10.1007/s12223-009-0048-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 03/31/2009] [Indexed: 10/20/2022]
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Hirakawa Y, Nagamune K, Ishida KI. Protein targeting into secondary plastids of chlorarachniophytes. Proc Natl Acad Sci U S A 2009; 106:12820-5. [PMID: 19620731 PMCID: PMC2722280 DOI: 10.1073/pnas.0902578106] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Indexed: 01/08/2023] Open
Abstract
Most plastid proteins are encoded by the nuclear genome, and consequently, need to be transported into plastids across multiple envelope membranes. In diverse organisms possessing secondary plastids, nuclear-encoded plastid precursor proteins (preproteins) commonly have an N-terminal extension that consists of an endoplasmic reticulum (ER)-targeting signal peptide and a transit peptide-like sequence (TPL). This bipartite targeting peptide is believed to be necessary for targeting the preproteins into the secondary plastids. Here, we newly demonstrate the function of the bipartite targeting peptides of an algal group, chlorarachniophytes, and characterize the functional domains of the TPL in the precursor of a plastid protein, ATP synthase delta subunit (AtpD), using a GFP as a reporter molecule. We show that the C-terminal portion of the TPL is important for targeting the AtpD preprotein from the ER into the chlorarachniophyte plastids, and several positively charged amino acids in the TPL are also necessary for transporting the preprotein across the 2 innermost plastid membranes. Compared with other groups with secondary plastids, the TPL functional domains of the chlorarachniophytes are unique, which might be caused by independent acquisition of their plastids.
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Affiliation(s)
- Yoshihisa Hirakawa
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba 305-8572, Japan
| | - Kisaburo Nagamune
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba 305-8572, Japan
| | - Ken-ichiro Ishida
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba 305-8572, Japan
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Aronsson H, Jarvis P. The Chloroplast Protein Import Apparatus, Its Components, and Their Roles. PLANT CELL MONOGRAPHS 2008. [DOI: 10.1007/978-3-540-68696-5_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Abstract
Most chloroplast proteins are encoded in the nucleus and synthesized on free, cytosolic ribosomes in precursor form. Each precursor has an amino-terminal extension called a transit peptide, which directs the protein through a post-translational targeting pathway and is removed upon arrival inside the organelle. This 'protein import' process is mediated by the coordinate action of two multiprotein complexes, one in each of the envelope membranes: the TOC and TIC (Translocon at the Outer/ Inner envelope membrane of Chloroplasts) machines. Many components of these complexes have been identified biochemically in pea; these include transit peptide receptors, channel proteins, and molecular chaperones. Intriguingly, the Arabidopsis genome encodes multiple, homologous genes for receptor components of the TOC complex. Careful analysis indicated that the different receptor isoforms operate in different import pathways with distinct precursor recognition specificities. These 'substrate-specific' import pathways might play a role in the differentiation of different plastid types, and/or act to prevent deleterious competition effects between abundant and nonabundant precursors. Until recently, all proteins destined for internal chloroplast compartments were thought to possess a cleavable transit peptide, and to engage the TOC/TIC machinery. New studies using proteomics and other approaches have revealed that this is far from true. Remarkably, a significant number of chloroplast proteins are transported via a pathway that involves the endoplasmic reticulum and Golgi apparatus. Other recent reports have elucidated an intriguing array of protein targeting routes leading to the envelope membranes themselves.
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Affiliation(s)
- Paul Jarvis
- Department of Biology, University of Leicester, Leicester LE1 7RH, UK
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The Chloroplast Protein Import Apparatus, Its Components, and Their Roles. PLANT CELL MONOGRAPHS 2008. [DOI: 10.1007/7089_2008_40] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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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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Takishita K, Kawachi M, Noël MH, Matsumoto T, Kakizoe N, Watanabe MM, Inouye I, Ishida KI, Hashimoto T, Inagaki Y. Origins of plastids and glyceraldehyde-3-phosphate dehydrogenase genes in the green-colored dinoflagellate Lepidodinium chlorophorum. Gene 2007; 410:26-36. [PMID: 18191504 DOI: 10.1016/j.gene.2007.11.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 11/12/2007] [Accepted: 11/19/2007] [Indexed: 10/22/2022]
Abstract
The dinoflagellate Lepidodinium chlorophorum possesses "green" plastids containing chlorophylls a and b (Chl a+b), unlike most dinoflagellate plastids with Chl a+c plus a carotenoid peridinin (peridinin-containing plastids). In the present study we determined 8 plastid-encoded genes from Lepidodinium to investigate the origin of the Chl a+b-containing dinoflagellate plastids. The plastid-encoded gene phylogeny clearly showed that Lepidodinium plastids were derived from a member of Chlorophyta, consistent with pigment composition. We also isolated three different glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes from Lepidodinium-one encoding the putative cytosolic "GapC" enzyme and the remaining two showing affinities to the "plastid-targeted GapC" genes. In a GAPDH phylogeny, one of the plastid-targeted GapC-like sequences robustly grouped with those of dinoflagellates bearing peridinin-containing plastids, while the other was nested in a clade of the homologues of haptophytes and dinoflagellate genera Karenia and Karlodinium bearing "haptophyte-derived" plastids. Since neither host nor plastid phylogeny suggested an evolutionary connection between Lepidodinium and Karenia/Karlodinium, a lateral transfer of a plastid-targeted GapC gene most likely took place from a haptophyte or a dinoflagellate with haptophyte-derived plastids to Lepidodinium. The plastid-targeted GapC data can be considered as an evidence for the single origin of plastids in haptophytes, cryptophytes, stramenopiles, and alveolates. However, in the light of Lepidodinium GAPDH data, we need to closely examine whether the monophyly of the plastids in the above lineages inferred from plastid-targeted GapC genes truly reflects that of the host lineages.
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Affiliation(s)
- Kiyotaka Takishita
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan
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Parsons M, Karnataki A, Feagin JE, DeRocher A. Protein trafficking to the apicoplast: deciphering the apicomplexan solution to secondary endosymbiosis. EUKARYOTIC CELL 2007; 6:1081-8. [PMID: 17513565 PMCID: PMC1951102 DOI: 10.1128/ec.00102-07] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Marilyn Parsons
- Seattle Biomedical Research Institute, 307 Westlake Ave. North, Seattle, WA 98109, USA.
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21
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Oldenburg DJ, Rowan BA, Zhao L, Walcher CL, Schleh M, Bendich AJ. Loss or retention of chloroplast DNA in maize seedlings is affected by both light and genotype. PLANTA 2006; 225:41-55. [PMID: 16941116 DOI: 10.1007/s00425-006-0329-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2006] [Accepted: 05/20/2006] [Indexed: 05/10/2023]
Abstract
We examined the chloroplast DNA (cpDNA) from plastids obtained from wild type maize (Zea mays L.) seedlings grown under different light conditions and from photosynthetic mutants grown under white light. The cpDNA was evaluated by real-time quantitative PCR, quantitative DNA fluorescence, and blot-hybridization following pulsed-field gel electrophoresis. The amount of DNA per plastid in light-grown seedlings declines greatly from stalk to leaf blade during proplastid-to-chloroplast development, and this decline is due to cpDNA degradation. In contrast, during proplastid-to-etioplast development in the dark, the cpDNA levels increase from the stalk to the blade. Our results suggest that DNA replication continues in the etioplasts of the upper regions of the stalk and in the leaves. The cpDNA level decreases rapidly, however, after dark-grown seedlings are transferred to light and the etioplasts develop into photosynthetically active chloroplasts. Light, therefore, triggers the degradation of DNA in maize chloroplasts. The cpDNA is retained in the leaf blade of seedlings grown under red, but not blue light. We suggest that light signaling pathways are involved in mediating cpDNA levels, and that red light promotes replication and inhibits degradation and blue light promotes degradation. For five of nine photosynthetic mutants, cpDNA levels in expanded leaves are higher than in wild type, indicating that nuclear genotype can affect the loss or retention of cpDNA.
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Affiliation(s)
- Delene J Oldenburg
- Department of Biology, University of Washington, Box 355325, Seattle, WA 98195-5325, USA
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Tomova C, Geerts WJC, Müller-Reichert T, Entzeroth R, Humbel BM. New comprehension of the apicoplast of Sarcocystis by transmission electron tomography. Biol Cell 2006; 98:535-45. [PMID: 16706752 DOI: 10.1042/bc20060028] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION Apicomplexan parasites (like Plasmodium, Toxoplasma, Eimeria and Sarcocystis) contain a distinctive organelle, the apicoplast, acquired by a secondary endosymbiotic process analogous to chloroplasts and mitochondria. The apicoplast is essential for long-term survival of the parasite. This prokaryotic origin implies that molecular and metabolic processes in the apicoplast differ from those of the eukaryotic host cells and therefore offer options for specific chemotherapeutic treatment. We studied the apicoplast in high-pressure frozen and freeze-substituted cysts of Sarcocystis sp. from roe deer (Capreolus capreolus) to get better insight in apicoplast morphology. RESULTS AND CONCLUSIONS We observed that the apicoplast contains four continuous membranes. The two inner membranes have a circular shape with a constant distance from each other and large-sized protein complexes are located between them. The two outer membranes have irregular shapes. The periplastid membrane also contains large-sized protein complexes, while the outer membrane displays protuberances into the parasite cytoplasm. In addition, it is closely associated with the endoplasmic reticulum by 'contact sites'.
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Affiliation(s)
- Cveta Tomova
- Institut für Zoologie/Spezielle Zoologie, Technische Universität Dresden, Helmholtzstrasse 10, D-01062 Dresden, Germany
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23
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Durnford DG, Gray MW. Analysis of Euglena gracilis plastid-targeted proteins reveals different classes of transit sequences. EUKARYOTIC CELL 2006; 5:2079-91. [PMID: 16998072 PMCID: PMC1694827 DOI: 10.1128/ec.00222-06] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The plastid of Euglena gracilis was acquired secondarily through an endosymbiotic event with a eukaryotic green alga, and as a result, it is surrounded by a third membrane. This membrane complexity raises the question of how the plastid proteins are targeted to and imported into the organelle. To further explore plastid protein targeting in Euglena, we screened a total of 9,461 expressed sequence tag (EST) clusters (derived from 19,013 individual ESTs) for full-length proteins that are plastid localized to characterize their targeting sequences and to infer potential modes of translocation. Of the 117 proteins identified as being potentially plastid localized whose N-terminal targeting sequences could be inferred, 83 were unique and could be classified into two major groups. Class I proteins have tripartite targeting sequences, comprising (in order) an N-terminal signal sequence, a plastid transit peptide domain, and a predicted stop-transfer sequence. Within this class of proteins are the lumen-targeted proteins (class IB), which have an additional hydrophobic domain similar to a signal sequence and required for further targeting across the thylakoid membrane. Class II proteins lack the putative stop-transfer sequence and possess only a signal sequence at the N terminus, followed by what, in amino acid composition, resembles a plastid transit peptide. Unexpectedly, a few unrelated plastid-targeted proteins exhibit highly similar transit sequences, implying either a recent swapping of these domains or a conserved function. This work represents the most comprehensive description to date of transit peptides in Euglena and hints at the complex routes of plastid targeting that must exist in this organism.
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Affiliation(s)
- Dion G Durnford
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada E3B 5A3.
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Gilson PR, Su V, Slamovits CH, Reith ME, Keeling PJ, McFadden GI. Complete nucleotide sequence of the chlorarachniophyte nucleomorph: nature's smallest nucleus. Proc Natl Acad Sci U S A 2006; 103:9566-71. [PMID: 16760254 PMCID: PMC1480447 DOI: 10.1073/pnas.0600707103] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The introduction of plastids into different heterotrophic protists created lineages of algae that diversified explosively, proliferated in marine and freshwater environments, and radically altered the biosphere. The origins of these secondary plastids are usually inferred from the presence of additional plastid membranes. However, two examples provide unique snapshots of secondary-endosymbiosis-in-action, because they retain a vestige of the endosymbiont nucleus known as the nucleomorph. These are chlorarachniophytes and cryptomonads, which acquired their plastids from a green and red alga respectively. To allow comparisons between them, we have sequenced the nucleomorph genome from the chlorarachniophyte Bigelowiella natans: at a mere 373,000 bp and with only 331 genes, the smallest nuclear genome known and a model for extreme reduction. The genome is eukaryotic in nature, with three linear chromosomes containing densely packed genes with numerous overlaps. The genome is replete with 852 introns, but these are the smallest introns known, being only 18, 19, 20, or 21 nt in length. These pygmy introns are shown to be miniaturized versions of normal-sized introns present in the endosymbiont at the time of capture. Seventeen nucleomorph genes encode proteins that function in the plastid. The other nucleomorph genes are housekeeping entities, presumably underpinning maintenance and expression of these plastid proteins. Chlorarachniophyte plastids are thus serviced by three different genomes (plastid, nucleomorph, and host nucleus) requiring remarkable coordination and targeting. Although originating by two independent endosymbioses, chlorarachniophyte and cryptomonad nucleomorph genomes have converged upon remarkably similar architectures but differ in many molecular details that reflect two distinct trajectories to hypercompaction and reduction.
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Affiliation(s)
- Paul R. Gilson
- *Infection and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville 3050, Australia
| | - Vanessa Su
- School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Claudio H. Slamovits
- Department of Botany, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Michael E. Reith
- Institute for Marine Biosciences, National Research Council, Halifax, NS, Canada B3H 3Z1; and
| | - Patrick J. Keeling
- Department of Botany, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Geoffrey I. McFadden
- School of Botany, University of Melbourne, Victoria 3010, Australia
- To whom correspondence should be addressed. E-mail:
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Mullin KA, Lim L, Ralph SA, Spurck TP, Handman E, McFadden GI. Membrane transporters in the relict plastid of malaria parasites. Proc Natl Acad Sci U S A 2006; 103:9572-7. [PMID: 16760253 PMCID: PMC1480448 DOI: 10.1073/pnas.0602293103] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Malaria parasites contain a nonphotosynthetic plastid homologous to chloroplasts of plants. The parasite plastid synthesizes fatty acids, heme, iron sulfur clusters and isoprenoid precursors and is indispensable, making it an attractive target for antiparasite drugs. How parasite plastid biosynthetic pathways are fuelled in the absence of photosynthetic capture of energy and carbon was not clear. Here, we describe a pair of parasite transporter proteins, PfiTPT and PfoTPT, that are homologues of plant chloroplast innermost membrane transporters responsible for moving phosphorylated C3, C5, and C6 compounds across the plant chloroplast envelope. PfiTPT is shown to be localized in the innermost membrane of the parasite plastid courtesy of a cleavable N-terminal targeting sequence. PfoTPT lacks such a targeting sequence, but is shown to localize in the outermost parasite plastid membrane with its termini projecting into the cytosol. We have identified these membrane proteins in the parasite plastid and determined membrane orientation for PfoTPT. PfiTPT and PfoTPT are proposed to act in tandem to transport phosphorylated C3 compounds from the parasite cytosol into the plastid. Thus, the transporters could shunt glycolytic derivatives of glucose scavenged from the host into the plastid providing carbon, reducing equivalents and ATP to power the organelle.
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Affiliation(s)
- Kylie A. Mullin
- *Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia; and
| | - Liting Lim
- *Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia; and
| | - Stuart A. Ralph
- *Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia; and
| | - Timothy P. Spurck
- *Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia; and
| | - Emanuela Handman
- The Walter and Eliza Hall Institute of Medical Research, Parkville 3050, Australia
| | - Geoffrey I. McFadden
- *Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia; and
- To whom correspondence should be addressed. E-mail:
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Nassoury N, Wang Y, Morse D. Brefeldin A Inhibits Circadian Remodeling of Chloroplast Structure in the Dinoflagellate Gonyaulax. Traffic 2005; 6:548-61. [PMID: 15941407 DOI: 10.1111/j.1600-0854.2005.00296.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Circadian increases in the rate of carbon fixation in the dinoflagellate Gonyaulax are correlated with extensive plastid remodeling. One marker for this remodeling is mobilization of ribulose bisphosphate carboxylase/oxygenase (Rubisco) from the plastid periphery to plastid regions nearer the cell center called pyrenoids. Nuclear-encoded proteins such as Rubisco transit through the Golgi in dinoflagellates; hence, we blocked protein import into the plastids using Brefeldin A (BFA) to explore the mechanism for plastid remodeling. We find that pyrenoid formation normally occurs concurrently with increased Rubisco synthesis rates in vivo, and when BFA is given prior to the onset of Rubisco synthesis, pyrenoid formation is partially or completely inhibited by 0.1 or 0.3 microg/mL BFA, respectively. Rubisco synthesis itself is not affected, and BFA-treated cells accumulate Rubisco in novel structures we term BFA bodies. Interestingly, when given just after the onset of Rubisco synthesis, BFA delays but does not block Rubisco mobilization, suggesting that a timing signal for plastid remodeling is delivered to the organelles at the same time as newly synthesized Rubisco. BFA also inhibits the circadian increases in carbon fixation rates, supporting the hypothesis that the biochemical basis for this circadian rhythm may be Rubisco distribution within the plastid.
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Affiliation(s)
- Nasha Nassoury
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal, 4101 Sherbrooke est, Montreal, Quebec, Canada H1X2B2
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