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Wolfgang Löffelhardt - One of the best experts on this subject based on the ideXlab platform.
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the photosynthetic apparatus of the living fossil Cyanophora paradoxa
2011Co-Authors: Jürgen M. Steiner, Wolfgang LöffelhardtAbstract:Muroplasts, the peculiar plastids (previously called cyanelles) of glaucocystophyte algae did retain—with some modifications—the peptidoglycan wall of their cyanobacterial ancestor. This is not only a convincing proof of the endosymbiotic theory, but earns glaucocystophytes the status of living fossils, as peptidoglycan is found nowhere else among eukaryotes. Muroplasts show even more cyanobacterial features than other primitive plastids, e.g., rhodoplasts. Almost all data available at present come from one species, Cyanophora paradoxa. The plastome, containing a surplus of 50 protein genes compared to chloroplast genomes (Table 2.1) and about 30% of the transcriptome (ESTs) of this organism are sequenced and a genome project is in progress. While Cyanophora does not offer such possibilities for genetic analysis as the Chlamydomonas system, due to its reasonable growth rate it is amenable to biochemical investigations.
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transketolase from Cyanophora paradoxa in vitro import into cyanelles and pea chloroplasts and a complex history of a gene often but not always transferred in the context of secondary endosymbiosis
Journal of Eukaryotic Microbiology, 2009Co-Authors: Johannes Jakowitsch, William Martin, Oliver Deusch, Katrin Henze, Wolfgang LöffelhardtAbstract:. The glaucocystophyte Cyanophora paradoxa is an obligatorily photoautotrophic biflagellated protist containing cyanelles, peculiar plastids surrounded by a peptidoglycan layer between their inner and outer envelope membranes. Although the 136-kb cyanelle genome surpasses higher plant chloroplast genomes in coding capacity by about 50 protein genes, these primitive plastids still have to import >2,000 polypeptides across their unique organelle wall. One such protein is transketolase, an essential enzyme of the Calvin cycle. We report the sequence of the pre-transketolase cDNA from C. paradoxa and in vitro import experiments of precursor polypeptides into cyanelles and into pea chloroplasts. The transit sequence clearly indicates the localization of the gene product to cyanelles and is more similar to the transit sequences of the plant homologues than to transit sequences of other cyanelle precursor polypeptides with the exception of a cyanelle consensus sequence at the N-terminus. The mature sequence reveals conservation of the thiamine pyrophosphate binding site. A neighbor-net planar graph suggests that Cyanophora, higher plants, and the photosynthetic protist Euglena gracilis acquired their nuclear-encoded transketolase genes via endosymbiotic gene transfer from the cyanobacterial ancestor of plastids; in the case of Euglena probably entailing two transfers, once from the plastid in the green algal lineage and once again in the secondary endosymbiosis underlying the origin of Euglena's plastids. By contrast, transketolase genes in some eukaryotes with secondary plastids of red algal origin, such as Thalassiosira pseudonana, have retained the pre-existing transketolase gene germane to their secondary host.
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acclimation to low co2 by an inorganic carbon concentrating mechanism in Cyanophora paradoxa
Plant Cell and Environment, 2007Co-Authors: Suzanne C Burey, Hans J. Bohnert, V Poroyko, Z N Ergen, S Fathinejad, C Schuller, Norikazu Ohnishi, Hideya Fukuzawa, Wolfgang LöffelhardtAbstract:The glaucocystophyte Cyanophora paradoxa contains cyanelles, plastids with prokaroytic features such as a pepti- doglycan wall and a central proteinaceous inclusion body. While this central body includes the majority of the enzyme ribulose 1,5-bisphosphate carboxylase/oxgenase Rubisco), the presence of a carbon-concentrating mechanism (CCM) in C. paradoxa has only been hypothesized. Here, we present physiological data in support of a CCM: CO2 exchange activity as well as apparent affinity against inor- ganic carbon were found to increase under CO2-limiting stress. Further, expressed sequence tags (ESTs) of C. para- doxawereobtainedfromtwocDNAlibraries,onefromcells grown in high (CO2) conditions and one from cells grown under low (CO2) conditions. A cDNA microarray platform assembled from 2378 cDNA sequences revealed that 142 genes significantly responded to a shift from high to low (CO2).Trends in gene expression were comparable to those reported for Chlamydomonas reinhardtii and the cyano- bacterium Synechocystis 6803, both possessing a CCM. Amonggenesregulatedby(CO2),transcriptswereidentified encodingcarbonicanhydrases(CAs),Rubiscoactivaseanda putative bicarbonate transporter in C. paradoxa, likely functionally involved in the CCM. These results and the polyhedric appearance of the central body further support the hypothesis of a unique 'eukaryotic carboxysome' in Cyanophora.
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Protein translocation into and within cyanelles (Review)
Molecular Membrane Biology, 2005Co-Authors: Jürgen M. Steiner, Wolfgang LöffelhardtAbstract:The cyanelles of the glaucocystophyte alga Cyanophora paradoxa resemble endosymbiotic cyanobacteria in morphology, pigmentation and, especially, in the presence of a peptidoglycan wall situated between the inner and outer envelope membranes. However, it is now clear that cyanelles in fact are primitive plastids. Phylogenetic analyses of plastid, nuclear and mitochondrial genes support a single primary endosymbiotic event. In this scenario cyanelles and all other plastid types are derived from an ancestral photosynthetic organelle combining the high plastid gene content of the Porphyra purpurea rhodoplast and the peptidoglycan wall of glaucocystophyte cyanelles. This means that the import apparatus of all primary plastids should be homologous. Indeed, heterologous in vitro import can now be shown in both directions, provided a phenylalanine residue essential for cyanelle import is engineered into the N-terminal part of chloroplast transit peptides. The cyanelle and likely also the rhodoplast import apparat...
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Characterization of apcC, the nuclear gene for the phycobilisome core linker polypeptide L_c ^7.8 from the glaucocystophyte alga Cyanophora paradoxa. Import of the precursor into isolated cyanelles and integration of the mature p
Current Genetics, 2003Co-Authors: Jürgen M. Steiner, Johannes A. Pompe, Wolfgang LöffelhardtAbstract:Phycobilisomes are the complex and highly efficient light-harvesting antenna systems of cyanobacteria, glaucocystophyte algae and red algae. In the glaucocystophyte Cyanophora paradoxa , seven genes for (chromophoric) phycobilisome components are known thus far, which all reside on the cyanelle genome. Here, we report the sequence of apcC , specifying the precursor to the colorless polypeptide L_c ^7.8, the first core linker reported for a eukaryote. The precursor was efficiently imported in vitro into isolated cyanelles. Fractionation into thylakoid membranes and stroma and into intact phycobilisomes and soluble proteins, respectively, indicated a low but significant incorporation of the imported linker polypeptide into the phycobilisomes.
Hans J. Bohnert - One of the best experts on this subject based on the ideXlab platform.
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acclimation to low co2 by an inorganic carbon concentrating mechanism in Cyanophora paradoxa
Plant Cell and Environment, 2007Co-Authors: Suzanne C Burey, Hans J. Bohnert, V Poroyko, Z N Ergen, S Fathinejad, C Schuller, Norikazu Ohnishi, Hideya Fukuzawa, Wolfgang LöffelhardtAbstract:The glaucocystophyte Cyanophora paradoxa contains cyanelles, plastids with prokaroytic features such as a pepti- doglycan wall and a central proteinaceous inclusion body. While this central body includes the majority of the enzyme ribulose 1,5-bisphosphate carboxylase/oxgenase Rubisco), the presence of a carbon-concentrating mechanism (CCM) in C. paradoxa has only been hypothesized. Here, we present physiological data in support of a CCM: CO2 exchange activity as well as apparent affinity against inor- ganic carbon were found to increase under CO2-limiting stress. Further, expressed sequence tags (ESTs) of C. para- doxawereobtainedfromtwocDNAlibraries,onefromcells grown in high (CO2) conditions and one from cells grown under low (CO2) conditions. A cDNA microarray platform assembled from 2378 cDNA sequences revealed that 142 genes significantly responded to a shift from high to low (CO2).Trends in gene expression were comparable to those reported for Chlamydomonas reinhardtii and the cyano- bacterium Synechocystis 6803, both possessing a CCM. Amonggenesregulatedby(CO2),transcriptswereidentified encodingcarbonicanhydrases(CAs),Rubiscoactivaseanda putative bicarbonate transporter in C. paradoxa, likely functionally involved in the CCM. These results and the polyhedric appearance of the central body further support the hypothesis of a unique 'eukaryotic carboxysome' in Cyanophora.
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the cyanelles of Cyanophora paradoxa
Critical Reviews in Plant Sciences, 1997Co-Authors: Wolfgang Löffelhardt, Hans J. Bohnert, Donald A Bryant, Rudolf HagemannAbstract:Abstract The cyanelles of Cyanophora paradoxa, plastids surrounded by a peptidoglycan wall, are considered as a surviving example for an early stage of plastid evolution from endosymbiotic cyanobacteria. We highlight the model character of the system by focusing on three aspects: “organelle wall” structure, plastid genome organization, and protein translocation. The biosynthetic pathway for cyanelle peptidoglycan appears to be analogous to that in Escherichia coli. Also, the basic structure of this peculiar organelle wall corresponds to that of the E. coli sacculus, with one notable exception: the C-1 carboxyl group of the D-isoglutamyl residue is partially amidated with N-acetylputrescine. Cyanelles harbor on their completely sequenced 135.6-kb genome genes for approximately 150 polypeptides, many of which are nucleus encoded in higher plants. Nevertheless, there are striking parallels in genome organization between cyanelles (and other primitive plastids) and higher plant chloroplasts. The transit seque...
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the complete sequence of the Cyanophora paradoxa cyanelle genome glaucocystophyceae
1997Co-Authors: Wolfgang Löffelhardt, Hans J. Bohnert, Donald A BryantAbstract:The obligatorily autotrophic protist, Cyanophora paradoxa, harbors cyanelles, primitive plastids with the morphology and surrounding peptidoglycan sacculus of endosymbiotic cyanobacteria. The complete nucleotide sequence of the 135.6 kb cyanelle genome leaves no doubt about the plastid status of these unusual organelles. Peculiarities of genome organization that are found in cyanelles as well as in algal and higher plant chloroplasts support the hypothesis that all plastid types have a common origin (i.e., that only a singular primary endosymbiotic event occurred). The ancestral semiautonomous organelle, the protoplastid, would still have retained the prokaryotic wall in this scenario.
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Nucleotide sequence of the cyanelle genome fromCyanophora paradoxa
Plant Molecular Biology Reporter, 1995Co-Authors: Veronica L. Stirewalt, Cecilia Bohns Michalowski, Wolfgang Löffelhardt, Hans J. Bohnert, Donald A BryantAbstract:The complete nucleotide sequence of the cyanelle genome of Cyanophora paradoxa Pringsheim strain LB 555 was determined (accession number U30821). The circular molecule is 135,599 base pairs in length. The physical map of this DNA molecule is shown along with identified genes and open reading frames.
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nucleotide sequence of the cyanelle genome from Cyanophora paradoxa
Plant Molecular Biology Reporter, 1995Co-Authors: Veronica L. Stirewalt, Cecilia Bohns Michalowski, Wolfgang Löffelhardt, Hans J. Bohnert, Donald A BryantAbstract:The complete nucleotide sequence of the cyanelle genome ofCyanophora paradoxa Pringsheim strain LB 555 was determined (accession number U30821). The circular molecule is 135,599 base pairs in length. The physical map of this DNA molecule is shown along with identified genes and open reading frames.
Donald A Bryant - One of the best experts on this subject based on the ideXlab platform.
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the cyanelles of Cyanophora paradoxa
Critical Reviews in Plant Sciences, 1997Co-Authors: Wolfgang Löffelhardt, Hans J. Bohnert, Donald A Bryant, Rudolf HagemannAbstract:Abstract The cyanelles of Cyanophora paradoxa, plastids surrounded by a peptidoglycan wall, are considered as a surviving example for an early stage of plastid evolution from endosymbiotic cyanobacteria. We highlight the model character of the system by focusing on three aspects: “organelle wall” structure, plastid genome organization, and protein translocation. The biosynthetic pathway for cyanelle peptidoglycan appears to be analogous to that in Escherichia coli. Also, the basic structure of this peculiar organelle wall corresponds to that of the E. coli sacculus, with one notable exception: the C-1 carboxyl group of the D-isoglutamyl residue is partially amidated with N-acetylputrescine. Cyanelles harbor on their completely sequenced 135.6-kb genome genes for approximately 150 polypeptides, many of which are nucleus encoded in higher plants. Nevertheless, there are striking parallels in genome organization between cyanelles (and other primitive plastids) and higher plant chloroplasts. The transit seque...
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the complete sequence of the Cyanophora paradoxa cyanelle genome glaucocystophyceae
1997Co-Authors: Wolfgang Löffelhardt, Hans J. Bohnert, Donald A BryantAbstract:The obligatorily autotrophic protist, Cyanophora paradoxa, harbors cyanelles, primitive plastids with the morphology and surrounding peptidoglycan sacculus of endosymbiotic cyanobacteria. The complete nucleotide sequence of the 135.6 kb cyanelle genome leaves no doubt about the plastid status of these unusual organelles. Peculiarities of genome organization that are found in cyanelles as well as in algal and higher plant chloroplasts support the hypothesis that all plastid types have a common origin (i.e., that only a singular primary endosymbiotic event occurred). The ancestral semiautonomous organelle, the protoplastid, would still have retained the prokaryotic wall in this scenario.
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Nucleotide sequence of the cyanelle genome fromCyanophora paradoxa
Plant Molecular Biology Reporter, 1995Co-Authors: Veronica L. Stirewalt, Cecilia Bohns Michalowski, Wolfgang Löffelhardt, Hans J. Bohnert, Donald A BryantAbstract:The complete nucleotide sequence of the cyanelle genome of Cyanophora paradoxa Pringsheim strain LB 555 was determined (accession number U30821). The circular molecule is 135,599 base pairs in length. The physical map of this DNA molecule is shown along with identified genes and open reading frames.
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nucleotide sequence of the cyanelle genome from Cyanophora paradoxa
Plant Molecular Biology Reporter, 1995Co-Authors: Veronica L. Stirewalt, Cecilia Bohns Michalowski, Wolfgang Löffelhardt, Hans J. Bohnert, Donald A BryantAbstract:The complete nucleotide sequence of the cyanelle genome ofCyanophora paradoxa Pringsheim strain LB 555 was determined (accession number U30821). The circular molecule is 135,599 base pairs in length. The physical map of this DNA molecule is shown along with identified genes and open reading frames.
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ribonuclease p rna gene of the plastid chromosome from Cyanophora paradoxa
DNA Research, 1995Co-Authors: Evgeni L Shevelev, Wolfgang Löffelhardt, Donald A Bryant, Hans J. BohnertAbstract:The gene, rnpB, encoding the RNA portion of ribonuclease-P has been found in the cyanelle DNA of Cyanophora paradoxa. A secondary structure model for the cyanelle RNA fits into that for eubacterial Rapb-RNAs.
Marek Mutwil - One of the best experts on this subject based on the ideXlab platform.
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gene expression analysis of Cyanophora paradoxa reveals conserved abiotic stress responses between basal algae and flowering plants
New Phytologist, 2020Co-Authors: Camilla Ferrari, Marek MutwilAbstract:: The glaucophyte Cyanophora paradoxa represents the most basal member of the kingdom Archaeplastida, but the function and expression of most of its genes are unknown. This information is needed to uncover how functional gene modules, that is groups of genes performing a given function, evolved in the plant kingdom. We have generated a gene expression atlas capturing responses of Cyanophora to various abiotic stresses. The data were included in the CoNekT-Plants database, enabling comparative transcriptomic analyses across two algae and six land plants. We demonstrate how the database can be used to study gene expression, co-expression networks and gene function in Cyanophora, and how conserved transcriptional programs can be identified. We identified gene modules involved in phycobilisome biosynthesis, response to high light and cell division. While we observed no correlation between the number of differentially expressed genes and the impact on growth of Cyanophora, we found that the response to stress involves a conserved, kingdom-wide transcriptional reprogramming, which is activated upon most stresses in algae and land plants. The Cyanophora stress gene expression atlas and the tools found in the https://conekt.plant.tools/ database thus provide a useful resource to reveal functionally related genes and stress responses in the plant kingdom.
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gene expression analysis of Cyanophora paradoxa reveals conserved abiotic stress responses between basal algae and flowering plants
bioRxiv, 2019Co-Authors: Camilla Ferrari, Marek MutwilAbstract:O_LIThe glaucophyte Cyanophora paradoxa represents the most basal member of the Archaeplastida kingdom, however the function and expression of most of its genes are unknown. This information is needed to uncover how functional gene modules, i.e. groups of genes performing a given function, evolved in the plant kingdom.nC_LIO_LIWe have generated a gene expression atlas capturing responses of Cyanophora to various abiotic stresses. This data was included in the CoNekT-Plants database, enabling comparative transcriptomic analyses across two algae and six land plants.nC_LIO_LIWe demonstrate how the database can be used to study gene expression, co-expression networks and gene function in Cyanophora, and how conserved transcriptional programs can be identified. We identified gene modules involved in phycobilisome biosynthesis, response to high light and cell division. While we observed no correlation between the number of differentially expressed genes and the impact on growth of Cyanophora, we found that the response to stress involves a conserved, kingdom-wide transcriptional reprogramming, which is activated upon most stresses in algae and land plants.nC_LIO_LIThe Cyanophora stress gene expression atlas and the tools found in https://conekt.plant.tools/ database provide a useful resource to reveal functionally related genes and stress responses in the plant kingdom.nC_LI
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Analysis of an improved Cyanophora paradoxa genome assembly.
DNA Research, 2019Co-Authors: Dana C. Price, Steven G. Ball, Ursula Goodenough, Thamali Kariyawasam, Camilla Ferrari, Fabio Facchinelli, Marek Mutwil, Robyn Roth, Ugo CenciAbstract:Glaucophyta are members of the Archaeplastida, the founding group of photosynthetic eukaryotes that also includes red algae (Rhodophyta), green algae, and plants (Viridiplantae). Here we present a high-quality assembly, built using long-read sequences, of the ca. 100 Mb nuclear genome of the model glaucophyte Cyanophora paradoxa. We also conducted a quick-freeze deep-etch electron microscopy (QFDEEM) analysis of C. paradoxa cells to investigate glaucophyte morphology in comparison to other organisms. Using the genome data, we generated a resolved 115-taxon eukaryotic tree of life that includes a well-supported, monophyletic Archaeplastida. Analysis of muroplast peptidoglycan (PG) ultrastructure using QFDEEM shows that PG is most dense at the cleavage-furrow. Analysis of the chlamydial contribution to glaucophytes and other Archaeplastida shows that these foreign sequences likely played a key role in anaerobic glycolysis in primordial algae to alleviate ATP starvation under night-time hypoxia. The robust genome assembly of C. paradoxa significantly advances knowledge about this model species and provides a reference for exploring the panoply of traits associated with the anciently diverged glaucophyte lineage.
M. Kraus - One of the best experts on this subject based on the ideXlab platform.
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rps10 unreported for plastid dnas is located on the cyanelle genome of Cyanophora paradoxa and is contranscribed with the str operon genes
Current Genetics, 1991Co-Authors: C Neumannspallart, Hans J. Bohnert, M. Kraus, Johannes Jakowitsch, M Brandtner, Wolfgang LöffelhardtAbstract:rps10, encoding the plastid ribosomal protein S10, is a nuclear gene in higher plants and green algae, and is missing from the large ribosomal protein gene cluster of chlorophyll b-type plastids that contains components of the prokaryotic S10, spc and alpha operons. The cyanelle genome of Cyanophora paradoxa is shown to harbor rps10 as another specific feature of its organization. However, this novel plastid gene is not contiguous with the genes of the “S10” operon, but is adjacent to, and cotranscribed with, the str operon, a trait also found in archaebacteria.
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The cyanelle str operon from Cyanophora paradoxa: Sequence analysis and phylogenetic implications
Plant Molecular Biology, 1990Co-Authors: M. Kraus, M. Götz, W. LöffelhardtAbstract:The str operon containing the genes for the ribosomal proteins S12 ( rps12 ) and S7 ( rps7 ) and for the elongation factors G ( fus ) and Tu ( tufA ) has been characterized for some cyanobacteria and chloroplasts from algae and higher plants. In the case of plastids a stepwise reduction. by one and two genes, respectively, has been observed due to gene transfer to the nuclear genome. The nucleotide sequence of the str operon on the cyanelle genome from Cyanophora paradoxa was determined as a first example for a chlorophyll b -less plastid. It comprises rps12 , rps7 and tufA which are closely linked and not interrupted by introns. Transcript analysis revealed cotranscription of the two ribosomal protein genes whereas tufA gave rise to a monocistronic mRNA. Phylogenetic studies using these three different traits allowed an assessment of the position of Cyanophora paradoxa among oxygenic photoautotrophs.
