Regulationsmechanismen des Kohlenhydratmetabolismus in Diatomeen

Loading...
Thumbnail Image
Date
2008
Authors
Weber, Till
Editors
Contact
Journal ISSN
Electronic ISSN
ISBN
Bibliographical data
Publisher
Series
DOI (citable link)
ArXiv-ID
International patent number
Link to the license
EU project number
Project
Open Access publication
Collections
Restricted until
Title in another language
Mechanisms of regulation of the carbohydrate-metabolism in diatoms
Research Projects
Organizational Units
Journal Issue
Publication type
Dissertation
Publication status
Published in
Abstract
Diatoms are unicellular, photoautotrophic organisms, which can be found in all aquatic habitats. Diatom plastids probably evolved by secondary endocytobiosis, the uptake of a eukaryotic alga into another eukaryotic host cell. In the course of evolution the endosymbiont was reduced to a cell organelle. The genome sequences of the diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana recently have been sequenced.
The genes encoding enzymes of the Calvin cycle and the Ferredoxin/Thioredoxin-system were identified, and the localisation of the respective proteins was predicted by bioinformatic tools. Fusion of the respective presequences to GFP and the subsequent expression of the constructs in P. tricornutum demonstrated that the four Fructose-1,6-bisphosphatases, one Phosphogluconat Lactonase, one Ferredoxin/Thioredoxin Reductase, and the Thioredoxins F, M and Y are localised in the plastids. One 6-Phospho-Gluconolactone Dehydrogenase and one Thioredoxin H are possibly localised in the periplastidic space. The Seduheptulose-1,7-bisphosphatase, one Fructose-1,6-bisphosphatase, one NADPH-depended Thioredoxin Reductase and one Thioredoxin H are localised in the Cytosol. It was shown for P. tricornutum and T. pseudonana that the oxidative pentose phosphate pathway (OPP) is relocated to the cytosol. As a result of this transfer, the Seduheptulose-1,7-bisphosphatase is possibly physiologically integrated in the OPP. In P. tricornutum the regulation of the plastidic RPP via Thioredoxin F is limited to the Fructose-1,6-bisphosphatase. Two of the four isoforms can be probably regulated via the cysteine residues in the regulative centre. The kinetic properties of the Fructose-1,6-bisphosphatases in the crude cell extract of P. tricornutum is similar to other plastidic Fructose-1,6-bisphosphatases of higher plants. It was demonstrated that the transcription levels of nuclear encoded genes of the OPP and RPP are not changing during by the diurnal cell cycle. Some possible target proteins of Thioredoxin have been collected by a Thioredoxin affinity chromatography and identificated by mass spectrometric analyses.
Summary in another language
Diatomeen (Kieselalgen) sind einzellige, photoautotrophe Organismen, die in vielen aquatischen Standorten vorkommen. Diatomeen-Plastiden sind wahrscheinlich durch sekundäre Endocytobiose entstanden, der Aufnahme einer eukaryotischen Alge in eine eukaryotische Wirtszelle. Der Endosymbiont wurde im Laufe der Evolution zum Zellorganell reduziert. Die Sequenzen der Genome der Diatomeen Phaeodactylum tricornutum und Thalassiosira pseudonana sind komplett bekannt.
In dieser Arbeit konnten Gene für Enzyme des Calvin Zyklus und für das Ferredoxin/Thioredoxin-System identifiziert und bioinformatisch die Lokalisation der jeweiligen Proteine vorhergesagt werden. Durch Fusion von Präsequenzen an GFP und anschließender Expression in P. tricornutum konnte gezeigt werden, dass in den Plastiden u.a. vier Fruktose-1,6-Bisphosphatasen, eine Phosphogluconat Lactonase, eine Ferredoxin/Thioredoxin Reduktase, sowie Thioredoxine F, M und Y lokalisiert sind. Eine 6-Phospho-Gluconolacton Dehydrogenase und ein Thioredoxin H sind wahrscheinlich im periplastidären Raum lokalisiert. Die Seduheptulose-1,7-Bisphosphatase, eine Fruktose-1,6-Bisphosphatas, eine NADPH abhängige Thioredoxin Reduktase und ein Thioredoxin H sind dagegen im Cytosol lokalisiert. Für P. tricornutum und T. pseudonana konnte gezeigt werden, dass der reduktive (RPP) in den Plastiden und der oxidative Pentose Phosphatweg (OPP) im Cytosol lokalisiert sind. Aufgrund der Lokalisation ist die Seduheptulose-1,7-bisphosphatase wahrscheinlich in den OPP physiologisch eingegliedert. In den Plastiden wurde die Seduheptulose-1,7-bisphosphatase vermutlich durch die Transaldolase in dem RPP enzymatisch ersetzt. In P. tricornutum begrenzt sich die Regulation des plastidären RPP durch das Thioredoxin F nur noch auf die Fruktose-1,6-Bisphosphatase. Von den vier Isoformen sind wahrscheinlich zwei über die Cysteine im regulativen Zentrum regulierbar. Die Kinetik der Fruktose-1,6-Bisphosphatasen im Gesamtzellextrakt von P. tricornutum entspricht anderen plastidären Fruktose-1,6-Bisphosphatasen von höheren Pflanzen. Es konnte gezeigt werden, dass die Transkriptionen der kernkodierten Gene des OPP und des RPP nicht diurnal gesteuert sind. Durch eine Thioredoxin-Affinitätschromatographie konnten mögliche Zielproteine gesammelt und durch Massen Spektrometrische Analysen identifiziert werden.
Subject (DDC)
570 Biosciences, Biology
Keywords
Diatomeen,Kohlenhydratmetabolismus,Calvin Zyklus,Thioredoxin,diatoms,carbohydrate-metabilism,Calvin cycle,Thioredoxin
Conference
Review
undefined / . - undefined, undefined. - (undefined; undefined)
Cite This
ISO 690WEBER, Till, 2008. Regulationsmechanismen des Kohlenhydratmetabolismus in Diatomeen [Dissertation]. Konstanz: University of Konstanz
BibTex
@phdthesis{Weber2008Regul-7104,
  year={2008},
  title={Regulationsmechanismen des Kohlenhydratmetabolismus in Diatomeen},
  author={Weber, Till},
  address={Konstanz},
  school={Universität Konstanz}
}
RDF
<rdf:RDF
    xmlns:dcterms="http://purl.org/dc/terms/"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:bibo="http://purl.org/ontology/bibo/"
    xmlns:dspace="http://digital-repositories.org/ontologies/dspace/0.1.0#"
    xmlns:foaf="http://xmlns.com/foaf/0.1/"
    xmlns:void="http://rdfs.org/ns/void#"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema#" > 
  <rdf:Description rdf:about="https://kops.uni-konstanz.de/server/rdf/resource/123456789/7104">
    <dcterms:isPartOf rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/28"/>
    <dcterms:issued>2008</dcterms:issued>
    <dcterms:available rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2011-03-24T17:31:31Z</dcterms:available>
    <void:sparqlEndpoint rdf:resource="http://localhost/fuseki/dspace/sparql"/>
    <dcterms:hasPart rdf:resource="https://kops.uni-konstanz.de/bitstream/123456789/7104/1/Diss_TillWeber.pdf"/>
    <dcterms:title>Regulationsmechanismen des Kohlenhydratmetabolismus in Diatomeen</dcterms:title>
    <dcterms:rights rdf:resource="https://rightsstatements.org/page/InC/1.0/"/>
    <dc:contributor>Weber, Till</dc:contributor>
    <dspace:hasBitstream rdf:resource="https://kops.uni-konstanz.de/bitstream/123456789/7104/1/Diss_TillWeber.pdf"/>
    <dc:format>application/pdf</dc:format>
    <dc:language>deu</dc:language>
    <dspace:isPartOfCollection rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/28"/>
    <dc:rights>terms-of-use</dc:rights>
    <dcterms:alternative>Mechanisms of regulation of the carbohydrate-metabolism in diatoms</dcterms:alternative>
    <dc:creator>Weber, Till</dc:creator>
    <bibo:uri rdf:resource="http://kops.uni-konstanz.de/handle/123456789/7104"/>
    <foaf:homepage rdf:resource="http://localhost:8080/"/>
    <dcterms:abstract xml:lang="eng">Diatoms are unicellular, photoautotrophic organisms, which can be found in all aquatic habitats. Diatom plastids probably evolved by secondary endocytobiosis, the uptake of a eukaryotic alga into another eukaryotic host cell. In the course of evolution the endosymbiont was reduced to a cell organelle. The genome sequences of the diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana recently have been sequenced.&lt;br /&gt;The genes encoding enzymes of the Calvin cycle and the Ferredoxin/Thioredoxin-system were identified, and the localisation of the respective proteins was predicted by bioinformatic tools. Fusion of the respective presequences to GFP and the subsequent expression of the constructs in P. tricornutum demonstrated that the four Fructose-1,6-bisphosphatases, one Phosphogluconat Lactonase, one Ferredoxin/Thioredoxin Reductase, and the Thioredoxins F, M and Y are localised in the plastids. One 6-Phospho-Gluconolactone Dehydrogenase and one Thioredoxin H are possibly localised in the periplastidic space. The Seduheptulose-1,7-bisphosphatase, one Fructose-1,6-bisphosphatase, one NADPH-depended Thioredoxin Reductase and one Thioredoxin H are localised in the Cytosol. It was shown for P. tricornutum and T. pseudonana that the oxidative pentose phosphate pathway (OPP) is relocated to the cytosol. As a result of this transfer, the Seduheptulose-1,7-bisphosphatase is possibly physiologically integrated in the OPP. In P. tricornutum the regulation of the plastidic RPP via Thioredoxin F is limited to the Fructose-1,6-bisphosphatase. Two of the four isoforms can be probably regulated via the cysteine residues in the regulative centre. The kinetic properties of the Fructose-1,6-bisphosphatases in the crude cell extract of P. tricornutum is similar to other plastidic Fructose-1,6-bisphosphatases of higher plants. It was demonstrated that the transcription levels of nuclear encoded genes of the OPP and RPP are not changing during by the diurnal cell cycle. Some possible target proteins of Thioredoxin have been collected by a Thioredoxin affinity chromatography and identificated by mass spectrometric analyses.</dcterms:abstract>
    <dc:date rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2011-03-24T17:31:31Z</dc:date>
  </rdf:Description>
</rdf:RDF>
Internal note
xmlui.Submission.submit.DescribeStep.inputForms.label.kops_note_fromSubmitter
Contact
URL of original publication
Test date of URL
Examination date of dissertation
July 7, 2008
Method of financing
Comment on publication
Alliance license
Corresponding Authors der Uni Konstanz vorhanden
International Co-Authors
Bibliography of Konstanz
Refereed