Prof. Dr. Christian Schmitz-Linneweber
Profil
Forschungsthemen20
Analyse der Aktivierung plastidärer Translation und RNA-Stabilisierung durch PPR-Proteine und PPR-induzierte sRNAs
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 08/2013 - 09/2016 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
Analyse von Pentatricopeptide repeat Proteinen in vivo: Ziel-RNAs und Funktionen III
Quelle ↗Förderer: DFG Nachwuchsgruppe Zeitraum: 11/2009 - 09/2011 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
Chloroplastidäre Ribonukleoproteine: Stabilitätsgeber für chloroplastidäre RNAs während Stressantworten
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 09/2015 - 08/2018 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
Die Erforschung der plastidären GNATs: Acetylierung als Regulationsmechanismus in der Photosynthese und Seneszenz
Quelle ↗Förderer: DFG Sachbeihilfe Internationale Kooperation Zeitraum: 04/2026 - 03/2029 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
Funktionelle Analyse der lichtabhängigen Regulation der chloroplastidären Genexpression durch die Ribonukleoproteine CP31A und CP29A
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 04/2011 - 03/2013 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
Identifizierung von Proteinen, die am Häm-Transport von Plastiden ins Zytoplasma beteiligt sind.
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 09/2025 - 08/2027 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber, Prof. Dr. rer. nat. Bernhard Grimm
IGRK 2290/1: Grenzen überwinden: Molekulare Interaktionen bei Malaria
Quelle ↗Förderer: DFG Graduiertenkolleg Zeitraum: 09/2017 - 02/2022 Projektleitung: Prof. Dr. Kai Matuschewski
IGRK 2290: Grenzen überwinden: Molekulare Interaktionen bei Malaria
Quelle ↗Förderer: DFG Graduiertenkolleg Zeitraum: 09/2017 - 02/2024 Projektleitung: Prof. Dr. Kai Matuschewski
Maturase Proteins in Organellar Group-II Intron Splicing in Plants
Quelle ↗Förderer: German-Israeli Foundation Zeitraum: 01/2014 - 12/2017 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
NW/1: Die Rolle von zyklischen di-GMP in der regulation der multizellulären Differenzierung der Antibiotika synthetisierenden Bakterien Streptomyces
Quelle ↗Förderer: DFG Nachwuchsgruppe Zeitraum: 03/2016 - 11/2019 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
NW/2: Die Rolle von zyklischem di-GMP in der Regulation der multizellulären Differenzierung der Antibiotika synthetisierenden Bakterien Streptomyces
Quelle ↗Förderer: DFG Nachwuchsgruppe Zeitraum: 12/2019 - 11/2020 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
NW: Analyse von Pentatricopeptide repeat Proteinen in vivo: Ziel-RNAs und Funktionen I
Quelle ↗Förderer: DFG Nachwuchsgruppe Zeitraum: 11/2005 - 06/2009 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
NW: Analyse von Pentatricopeptide repeat Proteinen in vivo: Ziel-RNAs und Funktionen II
Quelle ↗Förderer: DFG Nachwuchsgruppe Zeitraum: 11/2007 - 10/2009 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
Quantitative, vergleichende und mechanistische Untersuchung der Robustheit, Anpassungsfähigkeit und Grenzen des schlanken Translationssystems von Chloroplasten
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 10/2026 - 09/2029 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
Regulation der chloroplastidären Genexpression durch die Maturase MatK
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 11/2010 - 10/2013 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
SFB 429 IV: Analyse von Ribonukleoproteinen in der lichtabhängigen Regulation chloroplastidärer Genexpression
Quelle ↗Förderer: DFG Sonderforschungsbereich Zeitraum: 01/2008 - 12/2010 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
SFB/TRR 175/1: Chloroplastidäre Ribonukleoproteine (cp RNPs) – Stabilisierung chloroplastidärer RNA-Reservoirs während der Akklimatisierungsantwort (TP A02)
Quelle ↗Förderer: DFG Sonderforschungsbereich Zeitraum: 07/2016 - 12/2020 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
SFB/TRR 175/2: Das chloroplastidäre Ribonukleoprotein CP29A – Stabilisierung von RNA-Pools im Chloroplasten während der Kälteakklimatisation (TP A02)
Quelle ↗Förderer: DFG Sonderforschungsbereich Zeitraum: 07/2020 - 06/2024 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
SFB/TRR 175/3: Das chloroplastidäre Ribonukleoprotein CP29A – Anpassung chloroplastidärer RNA-Pools während der Kälteakklimatisation (TP A02)
Quelle ↗Förderer: DFG Sonderforschungsbereich Zeitraum: 07/2024 - 06/2028 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
Quelle ↗Förderer: Horizon 2020: Research and Innovation Action (RIA) Zeitraum: 05/2015 - 10/2020 Projektleitung: Prof. Dr. Christian Schmitz-Linneweber
Mögliche Industrie-Partner10
Stand: 26.4.2026, 19:48:44 (Top-K=20, Min-Cosine=0.4)
- 35 Treffer85.0%
- Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other StrategiesK85.0%
- Climate-smart rewilding: ecological restoration for climate change mitigation, adaptation and biodiversity support in EuropeK85.0%
- Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
- 30 Treffer85.0%
- Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other StrategiesK85.0%
- Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
- 28 Treffer85.0%
- Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other StrategiesK85.0%
- Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
Landesamt für Verbraucherschutz, Landwirtschaft und Flurneuordnung Brandenburg
PT28 Treffer57.5%- Sortenstrategien bei landwirtschaftlichen Nutzpflanzen zur Anpassung an den KlimawandelP57.5%
- Sortenstrategien bei landwirtschaftlichen Nutzpflanzen zur Anpassung an den Klimawandel
- 27 Treffer57.5%
- Sortenstrategien bei landwirtschaftlichen Nutzpflanzen zur Anpassung an den KlimawandelP57.5%
- Sortenstrategien bei landwirtschaftlichen Nutzpflanzen zur Anpassung an den Klimawandel
- 28 Treffer57.5%
- Sortenstrategien bei landwirtschaftlichen Nutzpflanzen zur Anpassung an den KlimawandelP57.5%
- Sortenstrategien bei landwirtschaftlichen Nutzpflanzen zur Anpassung an den Klimawandel
- 11 Treffer56.2%
- Eukaryotic Unicellular Organism Biology – Systems Biology of the Control of Cell Growth and ProliferationP56.2%
- Eukaryotic Unicellular Organism Biology – Systems Biology of the Control of Cell Growth and Proliferation
- 19 Treffer54.1%
- Zuwendung im Rahmen des Programms „exist – Existenzgründungen aus der Wissenschaft“ aus dem Bundeshaushalt, Einzelplan 09, Kapitel 02, Titel 68607, Haushaltsjahr 2026, sowie aus Mitteln des Europäischen Strukturfonds (hier Euro-päischer Sozialfonds Plus – ESF Plus) Förderperiode 2021-2027 – Kofinanzierung für das Vorhaben: „exist Women“T54.1%
- Zuwendung im Rahmen des Programms „exist – Existenzgründungen aus der Wissenschaft“ aus dem Bundeshaushalt, Einzelplan 09, Kapitel 02, Titel 68607, Haushaltsjahr 2026, sowie aus Mitteln des Europäischen Strukturfonds (hier Euro-päischer Sozialfonds Plus – ESF Plus) Förderperiode 2021-2027 – Kofinanzierung für das Vorhaben: „exist Women“
- 14 Treffer53.5%
- Professionalisierung in der Deutsch-als-Zweitsprache-Förderung für geflüchtete Menschen mit LernschwierigkeitenT53.5%
- Professionalisierung in der Deutsch-als-Zweitsprache-Förderung für geflüchtete Menschen mit Lernschwierigkeiten
- 11 Treffer53.2%
- Twinning for Rechargeable Sodium-Ion Battery Research (TwinBat)T53.2%
- Twinning for Rechargeable Sodium-Ion Battery Research (TwinBat)
Publikationen25
Top 25 nach Zitationen — Quelle: OpenAlex (BAAI/bge-m3 embedded für Matching).
Trends in Plant Science · 828 Zitationen · DOI
Molecular Biology and Evolution · 399 Zitationen · DOI
Pentatricopeptide repeat (PPR) proteins form a huge family in plants (450 members in Arabidopsis and 477 in rice) defined by tandem repetitions of characteristic sequence motifs. Some of these proteins have been shown to play a role in posttranscriptional processes within organelles, and they are thought to be sequence-specific RNA-binding proteins. The origins of this family are obscure as they are lacking from almost all prokaryotes, and the spectacular expansion of the family in land plants is equally enigmatic. In this study, we investigate the growth of the family in plants by undertaking a genome-wide identification and comparison of the PPR genes of 3 organisms: the flowering plants Arabidopsis thaliana and Oryza sativa and the moss Physcomitrella patens. A large majority of the PPR genes in each of the flowering plants are intron less. In contrast, most of the 103 PPR genes in Physcomitrella are intron rich. A phylogenetic comparison of the PPR genes in all 3 species shows similarities between the intron-rich PPR genes in Physcomitrella and the few intron-rich PPR genes in higher plants. Intron-poor PPR genes in all 3 species also display a bias toward a position of their introns at their 5' ends. These results provide compelling evidence that one or more waves of retrotransposition were responsible for the expansion of the PPR gene family in flowering plants. The differing numbers of PPR proteins are highly correlated with differences in organellar RNA editing between the 3 species.
The Plant Cell · 301 Zitationen · DOI
The pentatricopeptide repeat (PPR) is a degenerate 35-amino acid repeat motif that is widely distributed among eukaryotes. Genetic, biochemical, and bioinformatic data suggest that many PPR proteins influence specific posttranscriptional steps in mitochondrial or chloroplast gene expression and that they may typically bind RNA. However, biological functions have been determined for only a few PPR proteins, and with few exceptions, substrate RNAs are unknown. To gain insight into the functions and substrates of the PPR protein family, we characterized the maize (Zea mays) nuclear gene ppr4, which encodes a chloroplast-targeted protein harboring both a PPR tract and an RNA recognition motif. Microarray analysis of RNA that coimmunoprecipitates with PPR4 showed that PPR4 is associated in vivo with the first intron of the plastid rps12 pre-mRNA, a group II intron that is transcribed in segments and spliced in trans. ppr4 mutants were recovered through a reverse-genetic screen and shown to be defective for rps12 trans-splicing. The observations that PPR4 is associated in vivo with rps12-intron 1 and that it is also required for its splicing demonstrate that PPR4 is an rps12 trans-splicing factor. These findings add trans-splicing to the list of RNA-related functions associated with PPR proteins and suggest that plastid group II trans-splicing is performed by different machineries in vascular plants and algae.
The Plant Cell · 255 Zitationen · DOI
Plant nuclear genomes encode hundreds of predicted organellar RNA binding proteins, few of which have been connected with their physiological RNA substrates and functions. In fact, among the largest family of putative RNA binding proteins in plants, the pentatricopeptide repeat (PPR) family, no physiologically relevant RNA ligands have been firmly established. We used the chloroplast-splicing factor CAF1 to demonstrate the fidelity of a microarray-based method for identifying RNAs associated with specific proteins in chloroplast extract. We then used the same method to identify RNAs associated with the maize (Zea mays) PPR protein CRP1. Two mRNAs whose translation is CRP1-dependent were strongly and specifically enriched in CRP1 coimmunoprecipitations. These interactions establish CRP1 as a translational regulator by showing that the translation defects in crp1 mutants are a direct consequence of the absence of CRP1. Additional experiments localized these interactions to the 5' untranslated regions and suggested a possible CRP1 interaction motif. These results enhance understanding of the PPR protein family by showing that a PPR protein influences gene expression through association with specific mRNAs in vivo, suggesting an unusual mode of RNA binding for PPR proteins, and highlighting the possibility that translational regulation may be a particularly common function of PPR proteins. Analogous methods should have broad application for the study of native RNA-protein interactions in both mitochondria and chloroplasts.
Plant Molecular Biology · 219 Zitationen · DOI
The Pentatricopeptide Repeat Protein PPR5 Stabilizes a Specific tRNA Precursor in Maize Chloroplasts
2008Molecular and Cellular Biology · 181 Zitationen · DOI
Genes for pentatricopeptide repeat (PPR) proteins are found in all eukaryotic genomes analyzed but are particularly abundant in land plants. The majority of analyzed PPR proteins play a role in the processing or translation of organellar RNAs. Few PPR proteins have been studied in detail, and the functional repertoire and mechanisms of action of proteins in the PPR family are poorly understood. Here we analyzed a maize ortholog of the embryo-essential Arabidopsis thaliana gene AtPPR5. A genome-wide analysis of chloroplast RNAs that coimmunoprecipitate with Zea mays PPR5 (ZmPPR5) demonstrated that ZmPPR5 is bound in vivo to the unspliced precursor of trnG-UCC. Null and hypomorphic Zmppr5 insertion mutants are embryo viable but are deficient for chloroplast ribosomes and die as seedlings. These mutants show a dramatic decrease in both spliced and unspliced trnG-UCC RNAs, while the transcription of trnG-UCC is unaffected. These results, together with biochemical data documenting the sequence-specific binding of recombinant PPR5 to the trnG-UCC group II intron, suggest that PPR5 stabilizes the trnG-UCC precursor by directly binding and protecting an endonuclease-sensitive site. These findings add to the evidence that chloroplast-localized PPR proteins that are embryo essential in Arabidopsis typically function in the biogenesis of the plastid translation machinery.
Proceedings of the National Academy of Sciences · 171 Zitationen · DOI
Bacterial group II introns encode maturase proteins required for splicing. In organelles of photosynthetic land plants, most of the group II introns have lost the reading frames for maturases. Here, we show that the plastidial maturase MatK not only interacts with its encoding intron within trnK-UUU, but also with six additional group II introns, all belonging to intron subclass IIA. Mapping analyses of RNA binding sites revealed MatK to recognize multiple regions within the trnK intron. Organellar group II introns are considered to be the ancestors of nuclear spliceosomal introns. That MatK associates with multiple intron ligands makes it an attractive model for an early trans-acting nuclear splicing activity.
International Journal of Molecular Sciences · 139 Zitationen · DOI
Numerous studies highlighted the beneficial effects of the Mediterranean diet (MD) in maintaining health, especially during ageing. Even neurodegeneration, which is part of the natural ageing process, as well as the foundation of ageing-related neurodegenerative disorders like Alzheimer's and Parkinson's disease (PD), was successfully targeted by MD. In this regard, olive oil and its polyphenolic constituents have received increasing attention in the last years. Thus, this study focuses on two main olive oil polyphenols, hydroxytyrosol (HT) and oleuropein aglycone (OLE), and their effects on ageing symptoms with special attention to PD. In order to avoid long-lasting, expensive, and ethically controversial experiments, the established invertebrate model organism <i>Caenorhabditis elegans</i> was used to test HT and OLE treatments. Interestingly, both polyphenols were able to increase the survival after heat stress, but only HT could prolong the lifespan in unstressed conditions. Furthermore, in aged worms, HT and OLE caused improvements of locomotive behavior and the attenuation of autofluorescence as a marker for ageing. In addition, by using three different <i>C. elegans</i> PD models, HT and OLE were shown i) to enhance locomotion in worms suffering from α-synuclein-expression in muscles or rotenone exposure, ii) to reduce α-synuclein accumulation in muscles cells, and iii) to prevent neurodegeneration in α-synuclein-containing dopaminergic neurons. Hormesis, antioxidative capacities and an activity-boost of the proteasome & phase II detoxifying enzymes are discussed as potential underlying causes for these beneficial effects. Further biological and medical trials are indicated to assess the full potential of HT and OLE and to uncover their mode of action.
The Plant Cell · 134 Zitationen · DOI
Chloroplast RNA metabolism is mediated by a multitude of nuclear encoded factors, many of which are highly specific for individual RNA processing events. In addition, a family of chloroplast ribonucleoproteins (cpRNPs) has been suspected to regulate larger sets of chloroplast transcripts. This together with their propensity for posttranslational modifications in response to external cues suggested a potential role of cpRNPs in the signal-dependent coregulation of chloroplast genes. We show here on a transcriptome-wide scale that the Arabidopsis thaliana cpRNPs CP31A and CP29A (for 31 kD and 29 kD chloroplast protein, respectively), associate with large, overlapping sets of chloroplast transcripts. We demonstrate that both proteins are essential for resistance of chloroplast development to cold stress. They are required to guarantee transcript stability of numerous mRNAs at low temperatures and under these conditions also support specific processing steps. Fine mapping of cpRNP-RNA interactions in vivo suggests multiple points of contact between these proteins and their RNA ligands. For CP31A, we demonstrate an essential function in stabilizing sense and antisense transcripts that span the border of the small single copy region and the inverted repeat of the chloroplast genome. CP31A associates with the common 3'-terminus of these RNAs and protects them against 3'-exonucleolytic activity.
CRS1 is a novel group II intron splicing factor that was derived from a domain of ancient origin
2001RNA · 129 Zitationen · DOI
Protein-dependent group II intron splicing provides a forum for exploring the roles of proteins in facilitating RNA-catalyzed reactions. The maize nuclear gene crs1 is required for the splicing of the group II intron in the chloroplast atpF gene. Here we report the molecular cloning of the crs1 gene and an initial biochemical characterization of its gene product. Several observations support the notion that CRS1 is a bona fide group II intron splicing factor. First, CRS1 is found in a ribonucleoprotein complex in the chloroplast, and cofractionation data provide evidence that this complex includes atpF intron RNA. Second, CRS1 is highly basic and includes a repeated domain with features suggestive of a novel RNA-binding domain. This domain is related to a conserved free-standing open reading frame of unknown function found in both the eubacteria and archaea. crs1 is the founding member of a gene family in plants that was derived by duplication and divergence of this primitive gene. In addition to its previously established role in atpF intron splicing, new genetic data implicate crs1 in chloroplast translation. The chloroplast splicing and translation functions of crs1 may be mediated by the distinct protein products of two crs1 mRNA forms that result from alternative splicing of the crs1 pre-mRNA.
Molecular Biology and Evolution · 128 Zitationen · DOI
The nuclear and plastid genomes of the plant cell form a coevolving unit which in interspecific combinations can lead to genetic incompatibility of compartments even between closely related taxa. This phenomenon has been observed for instance in Atropa-Nicotiana cybrids. We have sequenced the plastid chromosome of Atropa belladonna (deadly nightshade), a circular DNA molecule of 156,688 bp, and compared it with the corresponding published sequence of its relative Nicotiana tabacum (tobacco) to understand how divergence at the level of this genome can contribute to nuclear-plastid incompatibilities and to speciation. It appears that (1) regulatory elements, i.e., promoters as well as translational and replicational signal elements, are well conserved between the two species; (2) genes--including introns--are even more highly conserved, with differences residing predominantly in regions of low functional importance; and (3) RNA editotypes differ between the two species, which makes this process an intriguing candidate for causing rapid reproductive isolation of populations.
The Plant Journal · 126 Zitationen · DOI
Post-transcriptional maturation of plastid-encoded mRNAs from land plants includes editing by making cytidine to uridine alterations at highly specific positions; this usually restores codon identities for conserved amino acids that are important for the proper function of the affected proteins. In contrast to the rather constant number of editing sites their location varies greatly, even between closely related taxa. Here, we experimentally determined the specific pattern of editing sites (the editotype) of the plastid genome of Arabidopsis thaliana ecotype Columbia (Col-0). Based on phylogenetic analyses of plastid open reading frames, we identified 28 editing sites. Two editing events in the genes matK and ndhB seem to have evolved late during the evolution of flowering plants. Strikingly, they are embedded in almost identical sequence elements and seem to be phylogenetically co-processed. This suggests that the two sites are recognized by the same trans-factor, which could help to explain the hitherto enigmatic gain of editing sites in evolution. In order to trace variations in editotype at the subspecies level we examined two other A. thaliana accessions, Cape Verde Islands (Cvi-0) and Wassilewskija (Ws-2), for the Col-0 editing sites. Both Cvi-0 and Ws-2 possess and process the whole set of editing sites as determined in Col-0, but the consequences of RNA editing differ at one position between the ecotypes.
Short non-coding RNA fragments accumulating in chloroplasts: footprints of RNA binding proteins?
2011Nucleic Acids Research · 124 Zitationen · DOI
Chloroplast RNA metabolism is controlled and excecuted by hundreds of nuclear-encoded, chloroplast-localized RNA binding proteins. Contrary to the nucleo-cytosolic compartment or bacteria, there is little evidence for non-coding RNAs that play a role as riboregulators of chloroplasts. We mined deep-sequencing datasets to identify short (16-28 nt) RNAs in the chloroplast genome and found 50 abundant small RNAs (sRNAs) represented by multiple, in some cases, thousands of sequencing reads, whereas reads are in general absent from the surrounding sequence space. Other than sRNAs representing the most highly abundant mRNAs, tRNAs and rRNAs, most sRNAs are located in non-coding regions and many are found a short distance upstream of start codons. By transcript end mapping we show that the 5' and 3' termini of chloroplast RNAs coincide with the ends of sRNAs. Sequences of sRNAs identified in Arabidopsis are conserved between different angiosperm species and in several cases, we identified putative orthologs in rice deep sequencing datasets. Recently, it was suggested that small chloroplast RNA fragments could result from the protective action of pentatricopeptide repeat (PPR) proteins against exonucleases, i.e. footprints of RNA binding proteins. Our data support this scenario on a transcriptome-wide level and suggest that a large number of sRNAs are in fact remnants of PPR protein targets.
Proceedings of the National Academy of Sciences · 117 Zitationen · DOI
Chloroplast ribonucleoproteins (cpRNPs) are nuclear-encoded, highly abundant, and light-regulated RNA binding proteins. They have been shown to be involved in chloroplast RNA processing and stabilization in vitro and are phylogenetically related to the well-described heterogeneous nuclear ribonucleoproteins (hnRNPs). cpRNPs have been found associated with mRNAs present in chloroplasts and have been regarded as nonspecific stabilizers of chloroplast transcripts. Here, we demonstrate that null mutants of the cpRNP family member CP31A exhibit highly specific and diverse defects in chloroplast RNA metabolism. First, analysis of cp31a and cp31a/cp31b double mutants uncovers that these 2 paralogous genes participate nonredundantly in a combinatorial fashion in processing a subset of chloroplast editing sites in vivo. Second, a genome-wide analysis of chloroplast transcript accumulation in cp31a mutants detected a virtually complete loss of the chloroplast ndhF mRNA and lesser reductions for specific other mRNAs. Fluorescence analyses show that the activity of the NADH dehydrogenase complex, which also includes the NdhF subunit, is defective in cp31a mutants. This indicates that cpRNPs are important in vivo for calibrating the expression levels of specific chloroplast mRNAs and impact chloroplast physiology. Taken together, the specificity and combinatorial aspects of cpRNP functions uncovered suggest that these chloroplast proteins are functional equivalents of nucleocytosolic hnRNPs.
International Journal of Molecular Sciences · 112 Zitationen · DOI
Parkinson's disease (PD) is the second most prevalent late-age onset neurodegenerative disorder, affecting 1% of the population after the age of about 60 years old and 4% of those over 80 years old, causing motor impairments and cognitive dysfunction. Increasing evidence indicates that Mediterranean diet (MD) exerts beneficial effects in maintaining health, especially during ageing and by the prevention of neurodegenerative disorders. In this regard, olive oil and its biophenolic constituents like hydroxytyrosol (HT) have received growing attention in the past years. Thus, in the current study we test the health-promoting effects of two hydroxytyrosol preparations, pure HT and Hidrox<sup>®</sup> (HD), which is hydroxytyrosol in its "natural" environment, in the established invertebrate model organism <i>Caenorhabditis elegans</i>. HD exposure led to much stronger beneficial locomotion effects in wild type worms compared to HT in the same concentration. Consistent to this finding, in OW13 worms, a PD-model characterized by α-synuclein expression in muscles, HD exhibited a significant higher effect on α-synuclein accumulation and swim performance than HT, an effect partly confirmed also in swim assays with the UA44 strain, which features α-synuclein expression in DA-neurons. Interestingly, beneficial effects of HD and HT treatment with similar strength were detected in the lifespan and autofluorescence of wild-type nematodes, in the neuronal health of UA44 worms as well as in the locomotion of rotenone-induced PD-model. Thus, the hypothesis that HD features higher healthspan-promoting abilities than HT was at least partly confirmed. Our study demonstrates that HD polyphenolic extract treatment has the potential to partly prevent or even treat ageing-related neurodegenerative diseases and ageing itself. Future investigations including mammalian models and human clinical trials are needed to uncover the full potential of these olive compounds.
FEBS Letters · 110 Zitationen · DOI
Chloroplast C-to-U RNA editing is an essential post-transcriptional process. Here we analyzed RNA editing in Arabidopsis thaliana using strand-specific deep sequencing datasets from the wild-type and a mutant defective in RNA 3' end maturation. We demonstrate that editing at all sites is partial, with an average of 5-6% of RNAs remaining unedited. Furthermore, we identified nine novel sites with a low extent of editing. Of these, three sites are absent from the WT transcriptome because they are removed by 3' end RNA processing, but these regions accumulate, and are edited, in a mutant lacking polynucleotide phosphorylase.
The Plant Cell · 109 Zitationen · DOI
The subgenomes of the plant cell, the nuclear genome, the plastome, and the chondriome are known to interact through various types of coevolving macromolecules. The combination of the organellar genome from one species with the nuclear genome of another species often leads to plants with deleterious phenotypes, demonstrating that plant subgenomes coevolve. The molecular mechanisms behind this nuclear-organellar incompatibility have been elusive, even though the phenomenon is widespread and has been known for >70 years. Here, we show by direct and reverse genetic approaches that the albino phenotype of a flowering plant with the nuclear genome of Atropa belladonna (deadly nightshade) and the plastome of Nicotiana tabacum (tobacco) develops as a result of a defect in RNA editing of a tobacco-specific editing site in the plastid ATPase alpha-subunit transcript. A plastome-wide analysis of RNA editing in these cytoplasmic hybrids and in plants with a tobacco nucleus and nightshade chloroplasts revealed additional defects in the editing of species-specific editing sites, suggesting that differences in RNA editing patterns in general contribute to the pigment deficiencies observed in interspecific nuclear-plastidial incompatibilities.
Biochimica et Biophysica Acta (BBA) - Bioenergetics · 102 Zitationen · DOI
BMC Biology · 93 Zitationen · DOI
Our inspections indicate that several chloroplast-specific mechanisms evolved in land plants to remedy point mutations that occurred after the water-to-land transition. Thus, the complexity of chloroplast gene expression evolved to guarantee the functionality of chloroplast genetic information and may not, with some exceptions, be involved in regulatory functions.
Planta · 87 Zitationen · DOI
The Plant Journal · 81 Zitationen · DOI
The regulation of chloroplast translation by nuclear gene products makes a major contribution to the control of chloroplast gene expression, but the underlying mechanisms are poorly understood. We describe a pentatricopeptide repeat (PPR) protein in maize, ATP4, that is necessary for translation of the chloroplast atpB open reading frame. We demonstrate that ATP4 associates in vivo with sequences near the 5' end of the unusually long 5' UTR of the atpB/E mRNA, that it facilitates ribosome association with this mRNA, and that it is required for accumulation and activity of the chloroplast ATP synthase. ATP4 is multifunctional, in that it also enhances atpA translation and is required for accumulation of specific processed atpF and psaJ transcripts. ATP4 belongs to a sub-class of PPR proteins that include a small MutS-related (SMR) domain. SMR domains had previously been associated primarily with DNA-related functions, but our findings imply that at least some PPR-SMR proteins can act on RNA. ATP4 is orthologous to the Arabidopsis protein SVR7, but the phenotypes of atp4 and svr7 mutants suggest that the functions of these orthologs have not been strictly conserved.
Nucleic Acids Research · 77 Zitationen · DOI
Land plant organellar genomes encode a small number of genes, many of which are essential for respiration and photosynthesis. Organellar gene expression is characterized by a multitude of RNA processing events that lead to stable, translatable transcripts. RNA binding proteins (RBPs), have been shown to generate and protect transcript termini and eventually induce the accumulation of short RNA footprints. We applied knowledge of such RBP-derived footprints to develop software (sRNA miner) that enables identification of RBP footprints, or other clusters of small RNAs, in organelles. We used this tool to determine mitochondrial and chloroplast cosRNAs (clustered organellar sRNAs) in Arabidopsis. We found that in mitochondria, cosRNAs coincide with transcript 3'-ends, but are largely absent from 5'-ends. In chloroplasts this bias is absent, suggesting a different mode of 5' processing, possibly owing to different sets of RNases. Furthermore, we identified a large number of cosRNAs that represent silenced insertions of mitochondrial DNA in the nuclear genome of Arabidopsis. Steady-state RNA analyses demonstrate that cosRNAs display differential accumulation during development. Finally, we demonstrate that the chloroplast RBP PPR10 associates in vivo with its cognate cosRNA. A hypothetical role of cosRNAs as competitors of mRNAs for PPR proteins is discussed.
The Plant Journal · 75 Zitationen · DOI
Acclimation is the capacity to adapt to environmental changes within the lifetime of an individual. This ability allows plants to cope with the continuous variation in ambient conditions to which they are exposed as sessile organisms. Because environmental changes and extremes are becoming even more pronounced due to the current period of climate change, enhancing the efficacy of plant acclimation is a promising strategy for mitigating the consequences of global warming on crop yields. At the cellular level, the chloroplast plays a central role in many acclimation responses, acting both as a sensor of environmental change and as a target of cellular acclimation responses. In this Perspective article, we outline the activities of the Green Hub consortium funded by the German Science Foundation. The main aim of this research collaboration is to understand and strategically modify the cellular networks that mediate plant acclimation to adverse environments, employing Arabidopsis, tobacco (Nicotiana tabacum) and Chlamydomonas as model organisms. These efforts will contribute to 'smart breeding' methods designed to create crop plants with improved acclimation properties. To this end, the model oilseed crop Camelina sativa is being used to test modulators of acclimation for their potential to enhance crop yield under adverse environmental conditions. Here we highlight the current state of research on the role of gene expression, metabolism and signalling in acclimation, with a focus on chloroplast-related processes. In addition, further approaches to uncovering acclimation mechanisms derived from systems and computational biology, as well as adaptive laboratory evolution with photosynthetic microbes, are highlighted.
The Plant Cell · 73 Zitationen · DOI
Plant organellar RNA metabolism is run by a multitude of nucleus-encoded RNA-binding proteins (RBPs) that control RNA stability, processing, and degradation. In chloroplasts and mitochondria, these post-transcriptional processes are vital for the production of a small number of essential components of the photosynthetic and respiratory machinery-and consequently for organellar biogenesis and plant survival. Many organellar RBPs have been functionally assigned to individual steps in RNA maturation, often specific to selected transcripts. While the catalog of factors identified is ever-growing, our knowledge of how they achieve their functions mechanistically is far from complete. This review summarizes the current knowledge of plant organellar RNA metabolism taking an RBP-centric approach and focusing on mechanistic aspects of RBP functions and the kinetics of the processes they are involved in.
PLANT PHYSIOLOGY · 71 Zitationen · DOI
Plastid gene expression is crucial for organelle function, but the factors that control it are still largely unclear. Members of the so-called mitochondrial transcription termination factor (mTERF) family are found in metazoans and plants and regulate organellar gene expression at different levels. Arabidopsis (Arabidopsis thaliana) mTERF6 is localized in chloroplasts and mitochondria, and its knockout perturbs plastid development and results in seedling lethality. In the leaky mterf6-1 mutant, a defect in photosynthesis is associated with reduced levels of photosystem subunits, although corresponding messenger RNA levels are unaffected, whereas translational capacity and maturation of chloroplast ribosomal RNAs (rRNAs) are perturbed in mterf6-1 mutants. Bacterial one-hybrid screening, electrophoretic mobility shift assays, and coimmunoprecipitation experiments reveal a specific interaction between mTERF6 and an RNA sequence in the chloroplast isoleucine transfer RNA gene (trnI.2) located in the rRNA operon. In vitro, recombinant mTERF6 bound to its plastid DNA target site can terminate transcription. At present, it is unclear whether disturbed rRNA maturation is a primary or secondary defect. However, it is clear that mTERF6 is required for the maturation of trnI.2. This points to an additional function of mTERFs.
Kooperationen22
Bestätigte Forscher↔Partner-Paare aus HU-FIS — Gold-Standard-Positive für das Matching.
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
company
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
company
IGRK 2290: Grenzen überwinden: Molekulare Interaktionen bei Malaria
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
other
IGRK 2290/1: Grenzen überwinden: Molekulare Interaktionen bei Malaria
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
Quantitative, vergleichende und mechanistische Untersuchung der Robustheit, Anpassungsfähigkeit und Grenzen des schlanken Translationssystems von Chloroplasten
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
other
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
SFB/TRR 175/3: Das chloroplastidäre Ribonukleoprotein CP29A – Anpassung chloroplastidärer RNA-Pools während der Kälteakklimatisation (TP A02)
university
SFB/TRR 175/1: Chloroplastidäre Ribonukleoproteine (cp RNPs) – Stabilisierung chloroplastidärer RNA-Reservoirs während der Akklimatisierungsantwort (TP A02)
other
Quantitative, vergleichende und mechanistische Untersuchung der Robustheit, Anpassungsfähigkeit und Grenzen des schlanken Translationssystems von Chloroplasten
university
IGRK 2290/1: Grenzen überwinden: Molekulare Interaktionen bei Malaria
research_institute
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
SFB/TRR 175/1: Chloroplastidäre Ribonukleoproteine (cp RNPs) – Stabilisierung chloroplastidärer RNA-Reservoirs während der Akklimatisierungsantwort (TP A02)
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
Validating C. Elegans Healthspan Model for Better Understanding Factors Causing Health and Disease, to Develop Evidence Based Prevention, Diagnostic, Therapeutic and Other Strategies
university
Stammdaten
Identität, Organisation und Kontakt aus HU-FIS.
- Name
- Prof. Dr. Christian Schmitz-Linneweber
- Titel
- Prof. Dr.
- Fakultät
- Lebenswissenschaftliche Fakultät
- Institut
- Institut für Biologie
- Arbeitsgruppe
- Molekulare Genetik
- Telefon
- +49 30 2093-49700
- HU-FIS-Profil
- Quelle ↗
- Zuletzt gescrapt
- 26.4.2026, 01:12:04