Universitätspublikationen
Refine
Year of publication
- 2021 (199) (remove)
Document Type
- Article (143)
- Doctoral Thesis (47)
- Contribution to a Periodical (5)
- Preprint (3)
- Book (1)
Has Fulltext
- yes (199)
Is part of the Bibliography
- no (199) (remove)
Keywords
- aging (5)
- Podospora anserina (4)
- SARS-CoV-2 (3)
- Thermophile (3)
- Wood–Ljungdahl pathway (3)
- microglia (3)
- Acinetobacter (2)
- Bioaccumulation (2)
- Biodiversity (2)
- Biomarkers (2)
- COVID19-NMR (2)
- Climate change (2)
- DNA uptake (2)
- Desiccation resistance (2)
- Drought (2)
- European beech (2)
- Haloferax volcanii (2)
- Hydrogen-dependent CO2 reductase (2)
- Oaks (2)
- Saccharomyces cerevisiae (2)
- Solution NMR spectroscopy (2)
- Thermus (2)
- amplicon sequencing (2)
- animal welfare (2)
- bioacoustics (2)
- biodiversity (2)
- biosynthesis (2)
- brain cancer (2)
- climate change (2)
- conservation genetics (2)
- decomposition (2)
- migration (2)
- mitochondria (2)
- polyploidy (2)
- population genetics (2)
- ribosome (2)
- sleep (2)
- tumor microenvironment (2)
- tumor-associated macrophages (2)
- vocalization (2)
- 16S rRNA gene (1)
- 18S rRNA gene (1)
- 2cpsdummy′-O-ribose-methylation (1)
- 3′UTR length (1)
- 5'-UTR (1)
- 5_SL4 (1)
- 5′-UTR (1)
- A. thaliana (1)
- ABR (1)
- ADCD (1)
- AMPA receptors (1)
- AMPK (1)
- APA (1)
- ATP synthase (1)
- Acetobacterium woodii (1)
- Acetogen (1)
- Acetogenesis (1)
- Acetogenic bacteria (1)
- Acetogenic metabolism (1)
- Aedes (1)
- Agent-based modeling (1)
- Alcohol dehydrogenase (1)
- Aldehyde:ferredoxin oxidoreductase (1)
- Alien species (1)
- Allohormone pheromones (1)
- Alternative splicing (1)
- Amphibia (1)
- Amplexus (1)
- Anaerobes (1)
- Antarctica (1)
- Aposematism (1)
- Autism Spectrum disorder (1)
- B chromosome (1)
- Bacillariaphyceae (1)
- Benin (1)
- Benthic environment (1)
- Biocatalysis (1)
- Biofuels (1)
- Biomarker (1)
- Biotic interactions (1)
- Biotransformation (1)
- Birds (1)
- Blinatumomab (1)
- Breeding glands (1)
- Bremsen (1)
- Brudenell River (1)
- Business strategy in drug development (1)
- CAPON (1)
- CAZy (1)
- CD19 (1)
- CFIm (1)
- CLP protease (1)
- CO2 capture (1)
- CRISPR-Cas9 (1)
- CRISPR-Cas9 gene conversion (1)
- Canada (1)
- Canis lupus (1)
- Canis lupus familiaris (1)
- Carbohydrates (1)
- Carbon capture (1)
- Carnivora (1)
- Carnivores (1)
- Castor bean tick (1)
- Cellulase gene expression (1)
- Cercospora (1)
- Chagas disease (1)
- Chemical communication (1)
- Chemical dispersants (1)
- Chlorophyll fluorescence (1)
- ClpB (1)
- Colorectal Cancer (1)
- Community barcoding (1)
- Costs (1)
- Crude oil (1)
- Crustacea (1)
- Culicidae (1)
- D-Galacturonicacid (1)
- D. magna (1)
- Dehydration (medicine) (1)
- Depth (1)
- Developmental Biology (1)
- Docking domain (1)
- Drosophila (1)
- Drought reaction (1)
- Drug discovery and development (1)
- Drug therapy (1)
- ERAL1 (1)
- Earth sciences (1)
- Ecosystem services (1)
- Ecotoxicogenomics (1)
- Electron transport chain (1)
- Electron-bifurcating hydrogenase (1)
- Endocrine-disrupting compounds (1)
- Entomology (1)
- Environmental factors (1)
- Environmental fate (1)
- Environmental partitioning (1)
- Enzymatic hydrolysis (1)
- EphB4 (1)
- Equilibrium partitioning theory (1)
- Ethanol fermentation (1)
- European Beech (1)
- Evolutionary biology (1)
- Excretion (1)
- Exitrons (1)
- Extracted sugar beet press pulp (1)
- Extremophile (1)
- Extremophiles (1)
- F1Fo-ATP-synthase (1)
- FAD (1)
- FAD synthase (1)
- FAD1 (1)
- FIP1 (1)
- Fabaceae (1)
- Filamentous fungi (1)
- Flavoproteins (1)
- Foraminiferal (1)
- Freshwater Ecosystems (1)
- Freshwater invertebrate (1)
- Functional traits (1)
- GLUT2 (1)
- GLUT3 (1)
- GRIP1 (1)
- Genetic vectors (1)
- Genotoxicity (1)
- Genotyping and haplotyping (1)
- Geomagnetic field (1)
- HARS2 (1)
- Health care (1)
- Herbivores (1)
- Heterologous enzyme production (1)
- Hominins (1)
- Host-parasite interaction (1)
- Human health (1)
- Hybridization (1)
- Hydrogen storage (1)
- Hypothermia (1)
- IUCN protection categories (1)
- Immunotherapy (1)
- In vivo electrophysiology (1)
- InvaCost (1)
- Isopoda (1)
- Ixodes ricinus (1)
- Klebsiella (1)
- L-Galactonate (1)
- LARS2 (1)
- LASSO algorithm (1)
- Land cover (1)
- Larva (1)
- Leguminosae (1)
- Lepidoptera (1)
- Life-history (1)
- Long-read sequencing (1)
- MACE-seq (1)
- MEK inhibition (1)
- MMN (1)
- Macaronesia (1)
- Macrobenthosda (1)
- Magnetic compass (1)
- Magnetic conditioning (1)
- Magnetic map (1)
- Malpighiales (1)
- Marine ecosystem (1)
- Marine invertebrates (1)
- Maxent (1)
- Mediterranean climate (1)
- Mediterranean plants (1)
- Membrane proteins (1)
- Messinian salinity crisis (1)
- MetVF (1)
- Metabolic engineering (1)
- Metabolomics (1)
- Methylene-THF reductase (1)
- Methylene-tetrahydrofolate reductase (1)
- Methyltransferase (1)
- Microbiology (1)
- Microbiota (1)
- Microplastic (1)
- Microscopy (1)
- Mikroplastik (1)
- Mount Kilimanjaro (1)
- Museum samples (1)
- NMR assignments (1)
- NMR spectroscopy (1)
- NOS-I (1)
- NOS1AP (1)
- Namibia (1)
- Nature Interest Scale (NIS) (1)
- Nature contributions to people (1)
- Nature's Contributions to People (1)
- Neocaridina palmata (1)
- Neuroligins (1)
- Neurotoxicity (1)
- Non-canonical terpenes (1)
- Non-invasive sampling (1)
- Non-ribosomal peptide synthetase (NRPS) (1)
- Nothopassalora (1)
- OXPHOS (1)
- Oil spills (1)
- Oomycetes (1)
- Organic acid reduction (1)
- Organic micropollutants (1)
- Organoids (1)
- Osmostress (1)
- Oxford Nanopore Technologies (1)
- Oxidative stress (1)
- P. anserina (1)
- PaCRD1 (1)
- PaIAP (1)
- Parkinson (1)
- Parkinson’s disease (1)
- Passalora (1)
- Pathogen (1)
- Pathways (1)
- Pectin (1)
- Peptide-antimicrobial-Xenorhabdus (PAX) peptide (1)
- Peronosporaceae (1)
- Persistence (1)
- Pesticides (1)
- Photosynthesis (1)
- Pink1 (1)
- Plant sciences (1)
- Plants (1)
- Plastic response (1)
- Polymer (1)
- Population density (1)
- Prenyl pyrophosphates (1)
- Pseudocercospora (1)
- Purkinje cell (1)
- Quality of life (1)
- RMP1 (1)
- RNA (1)
- RNA genome (1)
- RNA polymerase (1)
- RNA-binding proteins (1)
- Reverse transcription (1)
- Rhodnius prolixus (1)
- Risk assessment (1)
- Rnf complex (1)
- Robert Koch Institute (1)
- S9 (1)
- SL1 (1)
- SNF1 (1)
- SNP (1)
- SNP genotyping (1)
- SRSF3 (1)
- SRSF7 (1)
- SSA (1)
- Schistosomiaisis (1)
- Sea water (1)
- Shores (1)
- Sign posts (1)
- Sodefrin precursor-like factor (1)
- Solanum lycopersicum (1)
- Southern Ocean (1)
- Sporisorium reilianum (1)
- Stechmücken (1)
- Summer drought (1)
- Supervised machine learning (1)
- Swimming (1)
- Synaptic transmission (1)
- Synaptosomal preparation (1)
- Synthesis gas (1)
- TDOA (1)
- TWNK (1)
- Tabanidae (1)
- Terpenes (1)
- Thalassiosira (1)
- Thermoanaerobacter (1)
- Thermoascus aurantiacus (1)
- Thermophiles (1)
- Thermophilic acetogenic bacteria (1)
- Thiolation domain (1)
- Tick-borne diseases (1)
- Tie2 (1)
- Transcriptomics (1)
- Transgenic organisms (1)
- Traumatic mating (1)
- Tree rings (1)
- Trypanosoma cruzi (1)
- Tuber magnatum (1)
- Tylosis (1)
- UV/V cones (1)
- Uptake (1)
- Ustilago maydis (1)
- Ustilagomaydis (1)
- Variability (1)
- Vector-host-interaction (1)
- Verbreitung (1)
- Virtual screening (1)
- Virulence (1)
- Water accommodated fractions (1)
- Weather conditions (1)
- West Africa (1)
- Western Kenya (1)
- Wood properties (1)
- Wood-Ljungdahl pathway (1)
- X-ray crystallography (1)
- Xylem (1)
- Zea mays (1)
- Zebrafish (1)
- Zymomonas mobilis (1)
- aIF (1)
- abiotic factors (1)
- acetogenic bacteria (1)
- acetyl-CoA (1)
- acoustic features (1)
- acoustic multilateration (1)
- adaptive laboratory evolution (1)
- additives (1)
- adhesin (1)
- alarm calls (1)
- alpha-proteobacteria (1)
- alternative splicing (1)
- alzheimer’s disease (1)
- angiogenesis (1)
- angipoietin (1)
- animal cognition (1)
- animal detection (1)
- animal sounds (1)
- antipredator (1)
- apex bird species (1)
- aptamers (1)
- archaea (1)
- aroma (1)
- artificial docking domains (1)
- asexual reproduction (1)
- asgard group (1)
- ataxia (1)
- autophagy (1)
- bacteria (1)
- bacterial community (1)
- behavioral research (1)
- benthos (1)
- bioassays (1)
- biodiversity conservation (1)
- biodiversity in literature (1)
- bioinformatics (1)
- biological variables (1)
- biomarkers (1)
- biotic factors (1)
- bipartite networks (1)
- blood vessels (1)
- brain waves (1)
- breeding sites (1)
- cancer models (1)
- carbon monoxide (1)
- cardiovascular disease (1)
- carnivora (1)
- carotenoid biosynthesis (1)
- carotenoid structures (1)
- cell volume (1)
- cerebellum (1)
- cerebral metastasis (1)
- chassis cell (1)
- checkpoint inhibitors (1)
- chromosome organization (1)
- circadian clock (1)
- climate (1)
- climatic variables (1)
- co-knowledge production (1)
- coalescence (1)
- cobaltocene (1)
- communication (1)
- communication-mediating domains (1)
- compass orientation (1)
- complete chloroplast genome (1)
- complexome profiling (1)
- computational literary studies (1)
- connectedness to nature scale (CNS) (1)
- connection to nature (1)
- coupling (1)
- cox2 (1)
- cpDNA (1)
- cross-species RNA-sequencing (1)
- crustacea (1)
- cryo-EM (1)
- cryptochrome (1)
- cultural ecosystem services (1)
- custom (1)
- dPAS (1)
- deadwood (1)
- decision-making (1)
- deep-sea sediment (1)
- dendritic branching (1)
- dendritic morphology (1)
- denervation (1)
- development (1)
- diagnostics (1)
- differentially regulated orthologs (1)
- docking domains (1)
- domain architecture evolution (1)
- downy mildew (1)
- drug design (1)
- drug screening system (1)
- ecological risk assessment (1)
- ecology and biodiversity (1)
- ecospat (1)
- ecosystem management (1)
- ectomycorrhizal (1)
- effect monitoring (1)
- effectors (1)
- endocrine disruption (1)
- endophytes (1)
- endothelial cell (1)
- energy (1)
- energy conservation (1)
- engineering (1)
- environmental humanities (1)
- environmental pollution (1)
- enzymatic electrosynthesis (1)
- ephrinB2 (1)
- eukaryotic biodiversity (1)
- evolution (1)
- evolutionary traceability (1)
- expansion microscopy (1)
- experiment (1)
- exposome (1)
- exposure (1)
- extreme frost (1)
- extremophile (1)
- fishing (1)
- foliar pathogens (1)
- food contact materials (1)
- foraging (1)
- functional group (1)
- functional redundancy (1)
- functional richness (1)
- functional traits (1)
- fungal effectors (1)
- fungal traits (1)
- fungi (1)
- fuzzy clustering (1)
- gene conversion (1)
- gene families (1)
- gene models (1)
- genetic engineering (1)
- genome assembly and annotation (1)
- genome copy numbers (1)
- genomics (1)
- genotyping (1)
- geographical origin (1)
- giraffe behavior (1)
- glidobactins (1)
- global biomes (1)
- glucocorticoid receptor (1)
- glucocorticoid response (1)
- glucose transport inhibitor (1)
- graded structure (1)
- guanidine riboswitch (1)
- heat (1)
- heat and drought (1)
- heat stress (1)
- heat-shock protein (1)
- heteroplasmy (1)
- heterozygous cells (1)
- hippocampus (1)
- historical biodiversity (1)
- homeostasis (1)
- homeostatic plasticity (1)
- homologous gene expression (1)
- honey bees (1)
- horizontal gene transfer (1)
- host specificity (1)
- housing conditions (1)
- hxt0 yeast strain (1)
- hybrid enrichment (1)
- hydrogen evolution (1)
- hydrogen-dependent CO2 reductase (1)
- iCLIP (1)
- illustrated inclusion of nature in self scale (IINS) (1)
- in situ diversification (1)
- inclination compass (1)
- inclusion of nature in self scale (INS) (1)
- indel (1)
- individual interest (1)
- individuality (1)
- infectious diseases (1)
- infra-slow oscillation (1)
- interaction networks (1)
- interdisciplinarity (1)
- interest in nature (1)
- intersexuality (1)
- intra-tumor heterogeneity (1)
- invasive mammals (1)
- island biogeography (1)
- isolated nature reserves (1)
- land use (1)
- landscape diversity (1)
- large subunit maturation (1)
- latitudinal gradient (1)
- learning difficulties (1)
- left ventricular hypertrophy (1)
- leukodystrophy (1)
- light (1)
- light stimuli (1)
- light-harvesting (1)
- lipid metabolism (1)
- local factors (1)
- long noncoding RNA (1)
- long-distance dispersa (1)
- mPTP (1)
- mRNA (1)
- mRNA isoforms (1)
- macroevolution (1)
- magnetoreception (1)
- maladaptation (1)
- marine protected areas (1)
- maturity (1)
- maximum likelihood (1)
- mean fruit body size (1)
- mechanics (1)
- mediterranean (1)
- meerkats (1)
- metabarcoding (1)
- metabolic engineering (1)
- metabolomics (1)
- metazoans (1)
- microbes (1)
- microplastics (1)
- microsatellite (1)
- missing data (1)
- mitochondria localization (1)
- mitochondrial dysfunction (1)
- mitochondrial localization motif (1)
- mitophagy (1)
- modularity (1)
- molecular phylogenetic analysis (1)
- monetary impacts (1)
- morphology evaluation (1)
- mounting (1)
- mt DNA (1)
- multi-objective optimization (1)
- multi-omics technology (1)
- mushroom (1)
- mushroom spines (1)
- nNOS (1)
- natural behavior (1)
- nature relatedness scale (NR) (1)
- nematode diversity (1)
- neuro-vascular (1)
- neuroblast growth (1)
- neurodegeneration (1)
- neurodevelopment (1)
- nitric oxide (1)
- nocturnal activity (1)
- non-destructive sampling (1)
- non-invasive (1)
- non-material contribution (1)
- non-ribosomal peptide syntheses (1)
- non-ribosomal peptide synthetase (1)
- nontarget (1)
- novel natural products (1)
- npas4l (1)
- obligate pathogens (1)
- octanoic acid (1)
- off-target reads (1)
- one new species (1)
- oomycete (1)
- oomycetes (1)
- organotypic slice cultures (1)
- orthogroup (1)
- orthology (1)
- orthology assignment (1)
- oxygenic photosynthesis (1)
- pPAS (1)
- paleobiology (1)
- paralogy (1)
- parasitoid (1)
- pathogenicity (1)
- pathway complexity (1)
- pathway evolution (1)
- patient-derived organoids (1)
- peptide-antimicrobial-Xenorhabdus peptide (1)
- peroxisomes (1)
- personalized oncology (1)
- phosphoketolase (1)
- phosphotransacetylase (1)
- photocycle (1)
- phylogenetic conflict (1)
- phylogenetic informativeness (1)
- phylogenetic profiles (1)
- phylogenetic profiling (1)
- phylogenomics (1)
- phylogeny (1)
- physiological stress (1)
- planning and design (1)
- plasma (1)
- plastome (1)
- playback experiment (1)
- policies (1)
- politics and governance (1)
- pollinator crisis (1)
- polymers (1)
- population genomics (1)
- postglacial colonisation (1)
- pre-mRNA (1)
- precipitation (1)
- predation (1)
- prediction error (1)
- priority natural areas (1)
- probe kit (1)
- proliferation (1)
- pronephric duct (1)
- propagating waves (1)
- proteasome inhibitors (1)
- protein production (1)
- protoplast fusion (1)
- pseudouridylation (1)
- psychiatric disorders (1)
- qPCR (1)
- quality control (1)
- quantitative disease resistance (1)
- quercus (1)
- rRNA (1)
- raccoon dog (Nyctereutes procyonoides) (1)
- radical pair model (1)
- range boundary (1)
- range expansion (1)
- receptor (1)
- redox polymer (1)
- regulation (1)
- reinforcement statistical learning (1)
- reliability (1)
- repetition suppression (1)
- reptiles (1)
- resource losses (1)
- respiratory chain (1)
- rock-climbing impact (1)
- saprobic and ectomycorrhizal basidiomycetes (1)
- saprotrophic (1)
- scale development (1)
- sea-level fluctuations (1)
- seafloor bathymetry (1)
- sediment (1)
- senescence (1)
- sensory (1)
- shroom (1)
- signaling (1)
- snoRNA (1)
- social information (1)
- socio-economic sectors (1)
- sound localization (1)
- spatial analysis (1)
- special needs education (1)
- special needs students (1)
- specialization (1)
- speciation (1)
- species distribution model (1)
- stingless bee (1)
- structural biology (1)
- structure–activity relationships (1)
- sun exposure (1)
- suricates (1)
- survival rate (1)
- sustainable development (1)
- systems biology (1)
- targeted therapy (1)
- taxon sampling (1)
- taxonomy (1)
- temperate forest (1)
- temperature (1)
- text mining (1)
- thiolation domain (1)
- threatened cliff plant species (1)
- trait evolution (1)
- transcription (1)
- transcriptome (1)
- transcriptome analysis (1)
- transdisciplinarity (1)
- translation initiation (1)
- translocation (1)
- trophic interactions (1)
- tumor immunology (1)
- universal (1)
- university students (1)
- unselected segregation (1)
- validity (1)
- vasculogenesis (1)
- viruses (1)
- volatile (1)
- vulnerable marine ecosystems (1)
- water security (1)
- white truffle (1)
- xenology (1)
- zebrafish (1)
- zoo (1)
- zoo elephants (1)
- Ökotoxikologie (1)
Institute
- Biowissenschaften (199) (remove)
Background: Nitric oxide synthase 1 adaptor protein (NOS1AP; previously named CAPON) is linked to the glutamatergic postsynaptic density through interaction with neuronal nitric oxide synthase (nNOS). NOS1AP and its interaction with nNOS have been associated with several mental disorders. Despite the high levels of NOS1AP expression in the hippocampus and the relevance of this brain region in glutamatergic signalling as well as mental disorders, a potential role of hippocampal NOS1AP in the pathophysiology of these disorders has not been investigated yet.
Methods: To uncover the function of NOS1AP in hippocampus, we made use of recombinant adeno-associated viruses to overexpress murine full-length NOS1AP or the NOS1AP carboxyterminus in the hippocampus of mice. We investigated these mice for changes in gene expression, neuronal morphology, and relevant behavioural phenotypes.
Findings: We found that hippocampal overexpression of NOS1AP markedly increased the interaction of nNOS with PSD-95, reduced dendritic spine density, and changed dendritic spine morphology at CA1 synapses. At the behavioural level, we observed an impairment in social memory and decreased spatial working memory capacity.
Interpretation: Our data provide a mechanistic explanation for a highly selective and specific contribution of hippocampal NOS1AP and its interaction with the glutamatergic postsynaptic density to cross-disorder pathophysiology. Our findings allude to therapeutic relevance due to the druggability of this molecule.
Cryo-electron tomography is the only technique that can provide sub-nanometer resolved images of cell regions or even whole cells, without the need of labeling or staining methods. Technological advances over the past decade in electron microscope stability, cameras, stage precision and software have resulted in faster acquisition speeds and considerably improved resolution. In pursuit of even better image resolution, researchers seek to reduce noise – a crucial factor affecting the reliability of the tomogram interpretation and ultimately limiting the achieved resolution. Sub-tomogram averaging is the method of choice for reducing noise in repetitive objects. However, when averaging is not applicable, a trade-off between reducing noise and conserving genuine image details must be achieved. Thus, denoising is an important process that improves the interpretability of the tomogram not only directly but also by facilitating other downstream tasks, such as segmentation and 3D visualization. Here, I review contemporary denoising techniques for cryo-electron tomography by taking into account noise-specific properties of both reconstruction and detector noise. The outcomes of different techniques are compared, in order to help researchers select the most appropriate for each dataset and to achieve better and more reliable interpretation of the tomograms.
Trypanosoma cruzi, the causative agent of Chagas disease (American trypanosomiasis), colonizes the intestinal tract of triatomines. Triatomine bugs act as vectors in the life cycle of the parasite and transmit infective parasite stages to animals and humans. Contact of the vector with T. cruzi alters its intestinal microbial composition, which may also affect the associated metabolic patterns of the insect. Earlier studies suggest that the complexity of the triatomine fecal metabolome may play a role in vector competence for different T. cruzi strains. Using high-resolution mass spectrometry and supervised machine learning, we aimed to detect differences in the intestinal metabolome of the triatomine Rhodnius prolixus and predict whether the insect had been exposed to T. cruzi or not based solely upon their metabolic profile. We were able to predict the exposure status of R. prolixus to T. cruzi with accuracies of 93.6%, 94.2% and 91.8% using logistic regression, a random forest classifier and a gradient boosting machine model, respectively. We extracted the most important features in producing the models and identified the major metabolites which assist in positive classification. This work highlights the complex interactions between triatomine vector and parasite including effects on the metabolic signature of the insect.
Aim: The identification of the mechanisms determining spatial variation in biological diversity along elevational gradients is a central objective in ecology and biogeography. Here, we disentangle the direct and indirect effects of abiotic drivers (climatic conditions, and land use) and biotic drivers (vegetation structure and food resources) on functional diversity and composition of bird and bat assemblages along a tropical elevational gradient. Location: Southern slopes of Mt. Kilimanjaro, Tanzania, East Africa. Methods: We counted birds and recorded bat sonotypes on 58 plots distributed in near-natural and anthropogenically modified habitats from 700 to 4,600 m above sea level. For the recorded taxa, we compiled functional traits related to movement, foraging and body size from museum specimens and databases. Further, we recorded mean annual temperature, precipitation, vegetation complexity as well as the number of fruits, flowers, and insect biomass as measures of resource availability on each study site. Results: Using path analyses, we found similar responses of bird and bat functional diversity to the variation in abiotic and biotic drivers along the elevational gradient. In contrast, the functional composition of both taxa showed distinct responses to abiotic and biotic drivers. For both groups, direct temperature effects were most important, followed by resource availability, precipitation and vegetation complexity. Main Conclusions: Our findings indicate that physiological and metabolic constraints imposed by temperature and resource availability determine the functional diversity of bird and bat assemblages, whereas the composition of individual functional traits is driven by taxon-specific processes. Our study illustrates that distinct filtering mechanisms can result in similar patterns of functional diversity along broad environmental gradients. Such differences need to be taken into account when it comes to conserving the functional diversity of flying vertebrates on tropical mountains.
Butyrate production in the acetogen Eubacterium limosum is dependent on the carbon and energy source
(2021)
Eubacterium limosum KIST612 is one of the few acetogenic bacteria that has the genes encoding for butyrate synthesis from acetyl-CoA, and indeed, E. limosum KIST612 is known to produce butyrate from CO but not from H2 + CO2. Butyrate production from CO was only seen in bioreactors with cell recycling or in batch cultures with addition of acetate. Here, we present detailed study on growth of E. limosum KIST612 on different carbon and energy sources with the goal, to find other substrates that lead to butyrate formation. Batch fermentations in serum bottles revealed that acetate was the major product under all conditions investigated. Butyrate formation from the C1 compounds carbon dioxide and hydrogen, carbon monoxide or formate was not observed. However, growth on glucose led to butyrate formation, but only in the stationary growth phase. A maximum of 4.3 mM butyrate was observed, corresponding to a butyrate:glucose ratio of 0.21:1 and a butyrate:acetate ratio of 0.14:1. Interestingly, growth on the C1 substrate methanol also led to butyrate formation in the stationary growth phase with a butyrate:methanol ratio of 0.17:1 and a butyrate:acetate ratio of 0.33:1. Since methanol can be produced chemically from carbon dioxide, this offers the possibility for a combined chemical-biochemical production of butyrate from H2 + CO2 using this acetogenic biocatalyst. With the advent of genetic methods in acetogens, butanol production from methanol maybe possible as well.
The pyruvate:ferredoxin oxidoreductase of the thermophilic acetogen, Thermoanaerobacter kivui
(2021)
Pyruvate:ferredoxin oxidoreductase (PFOR) is a key enzyme in bacterial anaerobic metabolism. Since a low-potential ferredoxin (Fd2−) is used as electron carrier, PFOR allows for hydrogen evolution during heterotrophic growth as well as pyruvate synthesis during lithoautotrophic growth. The thermophilic acetogenic model bacterium Thermoanaerobacter kivui can use both modes of lifestyle, but the nature of the PFOR in this organism was previously unestablished. Here, we have isolated PFOR to apparent homogeneity from cells grown on glucose. Peptide mass fingerprinting revealed that it is encoded by pfor1. PFOR uses pyruvate as an electron donor and methylene blue (1.8 U·mg−1) and ferredoxin (Fd; 27.2 U·mg−1) as electron acceptors, and the reaction is dependent on thiamine pyrophosphate, pyruvate, coenzyme A, and Fd. The pH and temperature optima were 7.5 and 66 °C, respectively. We detected 13.6 mol of iron·mol of protein−1, consistent with the presence of three predicted [4Fe–4S] clusters. The ability to provide reduced Fd makes PFOR an interesting auxiliary enzyme for enzyme assays. To simplify and speed up the purification procedure, we established a protocol for homologous protein production in T. kivui. Therefore, pfor1 was cloned and expressed in T. kivui and the encoded protein containing a genetically engineered His-tag was purified in only two steps to apparent homogeneity. The homologously produced PFOR1 had the same properties as the enzyme from T. kivui. The enzyme can be used as auxiliary enzyme in enzymatic assays that require reduced Fd as electron donor, such as electron-bifurcating enzymes, to keep a constant level of reduced Fd.
In the past two decades, an increasing body of studies has been published on the intersex phenomenon in separate-sexed crustaceans from marine and freshwater ecosystems. Various causes are being considered that could have an influence on the occurrence of intersex. Besides genetic factors, environmental conditions such as photoperiodicity, temperature, salinity and parasitism, but also environmental pollution with endocrine disrupting chemicals (EDCs) are discussed. As part of a long-term monitoring (2012 – 2020) in north-west Brittany, we recorded the occurrence of intersex in the marine amphipod Echinogammarus marinus. We quantified the intersex incidence at marine and estuarine sites and analyzed the incidence in relation to the endocrine potential of the sediments. Intersex occurred with mean frequencies between 0.87% and 12%. It was striking that the incidence of intersex increased with increasing distance from the sea. Since the highest incidence was observed at the range boundary of this stenohaline species, we assume that intersex is triggered by endocrine potential and increasing stress due to increasing freshwater content − and thus an interplay of different environmental factors.
Background: Genome sequencing of all known eukaryotes on Earth promises unprecedented advances in biological sciences and in biodiversity-related applied fields such as environmental management and natural product research. Advances in long-read DNA sequencing make it feasible to generate high-quality genomes for many non–genetic model species. However, long-read sequencing today relies on sizable quantities of high-quality, high molecular weight DNA, which is mostly obtained from fresh tissues. This is a challenge for biodiversity genomics of most metazoan species, which are tiny and need to be preserved immediately after collection. Here we present de novo genomes of 2 species of submillimeter Collembola. For each, we prepared the sequencing library from high molecular weight DNA extracted from a single specimen and using a novel ultra-low input protocol from Pacific Biosciences. This protocol requires a DNA input of only 5 ng, permitted by a whole-genome amplification step.
Results: The 2 assembled genomes have N50 values >5.5 and 8.5 Mb, respectively, and both contain ∼96% of BUSCO genes. Thus, they are highly contiguous and complete. The genomes are supported by an integrative taxonomy approach including placement in a genome-based phylogeny of Collembola and designation of a neotype for 1 of the species. Higher heterozygosity values are recorded in the more mobile species. Both species are devoid of the biosynthetic pathway for β-lactam antibiotics known in several Collembola, confirming the tight correlation of antibiotic synthesis with the species way of life.
Conclusions: It is now possible to generate high-quality genomes from single specimens of minute, field-preserved metazoans, exceeding the minimum contig N50 (1 Mb) required by the Earth BioGenome Project.
Dealing with potential stress in species that have high husbandry requirements, such as elephants, is a challenge for zoos. The objective of the present study was to determine whether positive reinforcement training (PRT) and exposure to a novel object (NOV) for enrichment induced a salivary cortisol response indicative of activation of the hypothalamic–pituitary–adrenal (HPA) axis and which factors determine individual variation in this regard in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) for the analysis of cortisol (SACort) before and up to 60 min (in 10–15 min intervals) after the onset of PRT (three repeats) or NOV (nine repeats), which lasted 10 min. There was considerable individual variation in SACort in response to PRT or NOV. Using mixed models, we were able to control these and to reveal that PRT was associated with high SACort before and relatively low SACort after PRT, while NOV induced a moderate SACort increase. The individual differences in SACort were related to age and sex (NOV), while the effects of zoo, handling method (free vs. protected contact) and reproductive and social status were variable. We conclude that positive affective states, such as anticipation or arousal, should be taken into account when interpreting the differences in the SACort responses between PRT and NOV. In addition, understanding the individuality of stress will support management decisions aimed at promoting captive elephant welfare.
The main aim of this thesis work was to elucidate the catalytic mechanism of several enzyme complexes on the basis of their three-dimensional structure. All investigated enzyme complexes occur in the anaerobic energy metabolism and have an essential function by the challenging degradation of aromatic compounds and the flavin-based electron bifurcation (FBEB)/confurcation, an energy-coupling mechanism. More specifically, I studied the phthaloyl-CoA decarboxylase of Thauera chlorobenzoica (Pcd) involved in phthalate ester decomposition, the FBEB protein complexes lactate dehydrogenase/electron-transfer flavoprotein (Ldh/EtfAB) of Acetobacterium woodii, the heterodisulfide-related subunit HdrA of the sulfur- oxidizing bacteria Hyphomicrobium denitrificans (sHdrA). In addition, I contributed to the structure determination of the caffeyl-CoA reductase- EtfAB complex of A. woodii and the naphthoyl-CoA reductase of the sulfate-respiring enrichment culture N47 (mentioned in the Appendix E and F).
Learning and animal movement
(2021)
Integrating diverse concepts from animal behavior, movement ecology, and machine learning, we develop an overview of the ecology of learning and animal movement. Learning-based movement is clearly relevant to ecological problems, but the subject is rooted firmly in psychology, including a distinct terminology. We contrast this psychological origin of learning with the task-oriented perspective on learning that has emerged from the field of machine learning. We review conceptual frameworks that characterize the role of learning in movement, discuss emerging trends, and summarize recent developments in the analysis of movement data. We also discuss the relative advantages of different modeling approaches for exploring the learning-movement interface. We explore in depth how individual and social modalities of learning can matter to the ecology of animal movement, and highlight how diverse kinds of field studies, ranging from translocation efforts to manipulative experiments, can provide critical insight into the learning process in animal movement.
Background: Filamentous fungi are excellent lignocellulose degraders, which they achieve through producing carbohydrate active enzymes (CAZymes). CAZyme production is highly orchestrated and gene expression analysis has greatly expanded understanding of this important biotechnological process. The thermophilic fungus Thermoascus aurantiacus secretes highly active thermostable enzymes that enable saccharifications at higher temperatures; however, the genome-wide measurements of gene expression in response to CAZyme induction are not understood. Results: A fed-batch system with plant biomass-derived sugars D-xylose, L-arabinose and cellobiose established that these sugars induce CAZyme expression in T. aurantiacus. The C5 sugars induced both cellulases and hemicellulases, while cellobiose specifically induced cellulases. A minimal medium formulation was developed to enable gene expression studies of T. aurantiacus with these inducers. It was found that d-xylose and L-arabinose strongly induced a wide variety of CAZymes, auxiliary activity (AA) enzymes and carbohydrate esterases (CEs), while cellobiose facilitated lower expression of mostly cellulase genes. Furthermore, putative orthologues of different unfolded protein response genes were up-regulated during the C5 sugar feeding together with genes in the C5 sugar assimilation pathways. Conclusion: This work has identified two additional CAZyme inducers for T. aurantiacus, L-arabinose and cellobiose, along with D-xylose. A combination of biochemical assays and RNA-seq measurements established that C5 sugars induce a suite of cellulases and hemicellulases, providing paths to produce broad spectrum thermotolerant enzymatic mixtures.
In times of global climate change and the fear of dwindling resources, we are facing different considerable challenges such as the replacement of fossil fuel–based energy carriers with the coincident maintenance of the increasing energy supply of our growing world population. Therefore, CO2 capturing and H2 storing solutions are urgently needed. In this study, we demonstrate the production of a functional and biotechnological interesting enzyme complex from acetogenic bacteria, the hydrogen-dependent CO2 reductase (HDCR), in the well-known model organism Escherichia coli. We identified the metabolic bottlenecks of the host organisms for the production of the HDCR enzyme complex. Here we show that the recombinant expression of a heterologous enzyme complex transforms E. coli into a whole-cell biocatalyst for hydrogen-driven CO2 reduction to formate without the need of any external co-factors or endogenous enzymes in the reaction process. This shifts the industrial platform organism E. coli more and more into the focus as biocatalyst for CO2-capturing and H2-storage. Key points: A functional HDCR enzyme complex was heterologously produced in E. coli; The metabolic bottlenecks for HDCR production were identified; HDCR enabled E. coli cell to capture and store H2 and CO2 in the form of formate.
In Zeiten der globalen Klimaerwärmung und des Klimawandels werden Strategien zur Vermeidung, Reduzierung oder Wiederverwertung von CO2-Emissionen sowie die Abkehr von fossilen Energieträgern immer wichtiger. Aus diesem Grund finden Technologien zur Bindung, Speicherung und Wiederverwertung von CO2 immer größere Aufmerksamkeit und diverse chemische als auch biologische Ansätze werden verfolgt. Eine dieser Möglichkeiten umfasst die Reduktion von CO2 mit Hilfe von molekularem Wasserstoff. Im Prozess der direkten Hydrogenierung von CO2 zu Ameisensäure bzw. Formiat wird nicht nur CO2 gebunden, sondern ebenfalls H2 in flüssiger Form gespeichert. Die Ameisensäure weist gegenüber dem hochflüchtigen Wasserstoffgas verschiedene Vorteile auf und zählt zu der Gruppe der flüssigen, organischen Wasserstoffspeicherverbindungen. Daneben ist das Einsatzgebiet von Ameisensäure als Ausgangstoff für Chemikalien oder als mikrobielle Kohlenstoffquelle sehr vielseitig und die Verbindung erfreut sich zunehmenden Interesses.
Die Natur hält biologische Katalysatoren (Enzyme) für die Reduktion von CO2 bereit. Die Gruppe der obligat anaeroben, acetogenen Bakterien verwendet so genannte Formiatdehydrogenasen als CO2-Reduktasen, um CO2 im Wood-Ljungdahl-Weg (WLP) der Bakterien fixieren zu können. Diese Enzyme katalysieren die reversible 2-Elektronen Reduktion von CO2 zu Ameisensäure. Kürzlich konnte aus den beiden Vertretern A. woodii (mesophil) und T. kivui (thermophil) ein neuartiger, cytoplasmatischer Enzymkomplex isoliert werden. Dieser Enzymkomplex koppelt die Reduktion von CO2 direkt an die Oxidation von H2 und wird deshalb als Wasserstoff-abhängige CO2-Reduktase bezeichnet (engl. hydrogen-dependent CO2 reductase, HDCR). Die HDCR katalysiert dabei die reversible Hydrogenierung von CO2 zu Formiat mit annähernd gleicher Kinetik und gleichen Umsatzraten. Die bei der CO2 Reduktion erreichten Umsatzraten übertrafen dabei bisherige chemische als auch biologische Katalysatoren um mehre Größenordnungen.
Im Hinblick auf die besonderen katalytischen Eigenschaften der HDCRs wurde in dieser Arbeit die biotechnologische Anwendbarkeit der Enzyme als Biokatalysatoren zur Speicherung und Sequestrierung von H2 und CO2 in Form von Ameisensäure untersucht. Im Speziellen wurde ein HDCR-basiertes Ganz-Zell-System für das thermophile Bakterium T. kivui entwickelt. Um eine Ganz-Zell basierte Umwandlung von H2 und CO2 zu Formiat zu gewährleisten, wurde zuvor die Weiterverwertung des Formiats zu Acetat im WLP gestoppt. Durch eine Reduktion des zellulären ATP-Gehalts konnte eine weitere Prozessierung des aus der HDCR-Reaktion gebildeten Formiats im Zellstoffwechsel des Bakteriums unterbunden werden. Die Formiatbildung aus H2 und CO2 wurde in Zellsuspensionen von T. kivui untersucht und charakterisiert. Hier zeigten T. kivui Zellen die höchste spezifische Formiatbildungsrate, die bis dato in der Literatur genannt wurde. Ebenfalls wurde in dieser Arbeit die Umwandlung von Synthesegas (H2 + CO2 und CO) und CO zu Formiat geprüft. Bioenergetisch entkoppelte und auf CO-adaptierte T. kivui Zellen konnten in der Tat Synthesegas exklusiv zu Formiat umsetzen. Um die CO-Verwertung zu Acetat und Formiat im Stoffwechsel der Rnf- (A. woodii) und Ech-Acetogenen (T. kivui) verstehen zu können, wurden Mutanten von Δhdcr, ΔcooS, ΔhydBA, Δrnf and Δech2 von A. woodii und T. kivui zur Hilfe genommen. In beiden Organismen war die CO-basierte Formiatbildung vom Vorhandensein eines funktionalen HDCR-Enzymkomplexes abhängig.
Für eine mögliche biotechnologische Anwendung wurde die Maßstabsvergrößerung des Ganz-Zell-Systems angestrebt und hin zum Bioreaktormaßstab mit kontrollierten Prozessbedingungen skaliert. Diese Arbeit demonstriert die effiziente Umwandlung von H2 und CO2 zu Formiat und vice versa unter Verwendung eines Rührkesselreaktors. Der Prozess zeigte eine Effizienz von 100% für die Umwandlung von CO2 zu Formiat und spezifische Raten von 48.3 mmol g-1 h-1 wurden von A. woodii Zellen erreicht. Die spezifische H2-Produktionsrate (qH2) aus der Ameisensäureoxidation betrug 27.6 mmol g-1 h-1 und mehr als 2.12 M Ameisensäure konnte über einen Zeitraum von 195 h oxidiert werden. Wichtige Parameter der Enzymkatalyse wie Wechselzahl (engl. turnover frequency, TOF) und katalytische Produktivität (engl. turnover number, TON) wurden ebenfalls im Versuch bestimmt. Basierend auf dem generierten Prozessverständnis und der effizienten Reversibilität der katalysierten Reaktionen wurde abschließend ein Ganz-Zell-basierter Bioreaktoraufbau gewählt, der die vielfache Speicherung und Freisetzung von H2 in einem einzigen Rührkesselreaktor und unter Verwendung des gleichen Katalysators ermöglicht. Über eine Prozesszeit von 2 Wochen und 15 CO2 Reduktions-/Formiat Oxidations-Zyklen konnte so im Mittel 330 mM Formiat produziert und oxidiert werden.
Zusammenfassend thematisiert diese Arbeit die biotechnologische Anwendbarkeit eines Ganz-Zell-Systems zur Speicherung und Sequestrierung von H2 und CO2 in Form von Formiat und vice versa. Die katalytische Aktivität der betrachteten Organismen fußt dabei auf der Aktivität eines neuartigen Enzymkomplexes, der erstmals in der Gruppe der acetogenen Bakterien entdeckt wurde. Der als Wasserstoff-abhängige CO2-Reduktase bezeichnete Enzymkomplex könnte die zukünftige Konzipierung Enzym-inspirierter und effizienter chemischer Katalysatoren vorantreiben. Auch der Einsatz des Enzyms/der Zellen in so genannten Hydrogelen oder die Etablierung elektrochemischer Prozesse sind vorstellbar. Diese Arbeit stellt somit eine Basis für mögliche zukünftige Anwendungen des etablierten Ganz-Zell-Systems von A. woodii und T. kivui im Bereich der Wasserstoffökonomie dar.
Background: Through the rapid development in DNA sequencing methods and tools, microbiome studies on a various number of species were performed during the last decade. This advance makes it possible to analyze hundreds of samples from different species at the same time in order to obtain a general overview of the microbiota. However, there is still uncertainty on the variability of the microbiota of different animal orders and on whether certain bacteria within a species are subject to greater fluctuations than others. This is largely due to the fact that the analysis in most extensive comparative studies is based on only a few samples per species or per study site. In our study, we aim to close this knowledge gap by analyzing multiple individual samples per species including two carnivore suborders Canoidea and Feloidea as well as the orders of herbivore Perissodactyla and Artiodactyla held in different zoos. To assess microbial diversity, 621 fecal samples from 31 species were characterized by sequencing the V3–V4 region of the 16S rRNA gene using Illumina MiSeq.
Results: We found significant differences in the consistency of microbiota composition and in fecal microbial diversity between carnivore and herbivore species. Whereas the microbiota of Carnivora is highly variable and inconsistent within and between species, Perissodactyla and Ruminantia show fewer differences across species boundaries. Furthermore, low-abundance bacterial families show higher fluctuations in the fecal microbiota than high-abundance ones.
Conclusions: Our data suggest that microbial diversity is significantly higher in herbivores than in carnivores, whereas the microbiota in carnivores, unlike in herbivores, varies widely even within species. This high variability has methodological implications and underlines the need to analyze a minimum amount of about 10 samples per species. In our study, we found considerable differences in the occurrence of different bacterial families when looking at just three and six samples. However, from a sample number of 10 onwards, these within-species fluctuations balanced out in most cases and led to constant and more reliable results.
Sympathetic influences on articular cartilage regeneration capacity and osteoarthritis manifestation
(2021)
The pathogenesis of osteoarthritis (OA) involves articular cartilage, synovial tissue and subchondral bone and is therefore a disease of the whole joint. OA is characterized by progressive degradation of cartilage, synovial inflammation, osteophyte formation and subchondral bone sclerosis. Cartilage-surrounding tissues are innervated by tyrosine hydroxylase (TH)-positive sympathetic nerve fibers with the most important sympathetic neurotransmitter norepinephrine (NE) detected in the synovial fluid of OA patients. Furthermore, adrenergic receptors are expressed in different knee joint tissues. Most in vitro studies indicate a potential role of the β2-adrenergic receptor, which has been not investigated during OA pathogenesis in vivo. The role of the sympathetic nervous system (SNS) in OA progression has not yet been studied. Therefore, the objective of this study was to analyze how the SNS and NE influence the MSC dependent cartilage regeneration in vitro and the OA pathogenesis and manifestation in vivo.
In the first part of this study, the effect of NE on the chondrogenesis of sASC, which are known to play an important role in cartilage regeneration was analyzed in vitro. In the second part of this study, the role of the SNS was studied in vivo in mice that were sympathectomized chemically followed by surgically induced OA. The specific focus was on the β2-adrenergic receptor effects on OA pathogenesis, which were analyzed in β2-adrenergic receptor-deficient mice.
The in vitro experiments have shown that NE reduced the chondrogenic potential of sASCs by decreasing the expression of type II collagen and sGAG. NE mediated these effects mainly by the α2-AR signalling. Furthermore, NE treatment led to activation of the ERK1/2 signal pathway. These findings suggested that the sympathetic neurotransmitter NE might suppress the chondrogenic capacity of MSC and their dependent cartilage regeneration and may also play a role in OA progression and manifestation.
The in vivo study has shown that sympathectomy reduced synovial TH-positive nerve fibers in the synovium and the NE concentration in the spleen significantly. In WT mice, DMM leads to increased NE concentrations in the spleen compared to sham mice indicating an increased SNS activity after mechanical stress or inflammation due to DMM. Sympathectomy leads to less pronounced cartilage degeneration (OARSI score) after DMM compared to DMM in WT mice. Furthermore, the release of the type II collagen degradation fragment CTX-II was abolished in Syx DMM mice compared to WT DMM mice, suggesting that less SNS activity due to sympathectomy reduced the cartilage degeneration during OA pathogenesis. Similarly, sympathectomy decreased the synovitis score significantly after DMM compared to DMM in
WT mice. Synovitis in WT mice was accompanied by increased MMP-13 expression in the synovium after DMM, compared to Syx mice. Cartilage degeneration seemed to be driven mainly by the increased synovial inflammation accompanied by an increased MMP13 expression in synoviocytes and not in chondrocytes. The pathological changes in synovium and cartilage might also be linked to each other, as indicated by the moderate correlation between the synovial inflammation (synovitis score) and cartilage degeneration (OARSI score). Subchondral bone volume as well the thickness of the subchondral bone plate (SCBP) and calcified cartilage (CC) were increased in Syx mice compared to WT after DMM. The data on DMM induction in β2-AR deficient mice revealed that the β2-AR signaling is involved in cartilage degeneration and the aggravated subchondral bone changes as these mice had less pronounced cartilage degeneration compared to WT mice. While the cartilage degeneration was similar, the subchondral bone changes were more pronounced in β2-AR deficient mice compared to the Syx mice.
Overall, the SNS had differential effects in cartilage, synovium and subchondral bone. A reduced SNS activity by sympathectomy attenuated cartilage degeneration and synovitis but aggravated the OA specific subchondral bone changes. These findings provide new insights into the development of novel therapeutic strategies for OA by targeting the SNS in a tissue- specific manner.
Owing to their morphological complexity and dense network connections, neurons modify their proteomes locally, using mRNAs and ribosomes present in the neuropil (tissue enriched for dendrites and axons). Although ribosome biogenesis largely takes place in the nucleus and perinuclear region, neuronal ribosomal protein (RP) mRNAs have been frequently detected remotely, in dendrites and axons. Here, using imaging and ribosome profiling, we directly detected the RP mRNAs and their translation in the neuropil. Combining brief metabolic labeling with mass spectrometry, we found that a group of RPs rapidly associated with translating ribosomes in the cytoplasm and that this incorporation was independent of canonical ribosome biogenesis. Moreover, the incorporation probability of some RPs was regulated by location (neurites vs. cell bodies) and changes in the cellular environment (following oxidative stress). Our results suggest new mechanisms for the local activation, repair and/or specialization of the translational machinery within neuronal processes, potentially allowing neuronal synapses a rapid means to regulate local protein synthesis.
Owing to their morphological complexity and dense network connections, neurons modify their proteomes locally, using mRNAs and ribosomes present in the neuropil (tissue enriched for dendrites and axons). Although ribosome biogenesis largely takes place in the nucleus and perinuclear region, neuronal ribosomal protein (RP) mRNAs have been frequently detected remotely, in dendrites and axons. Here, using imaging and ribosome profiling, we directly detected the RP mRNAs and their translation in the neuropil. Combining brief metabolic labeling with mass spectrometry, we found that a group of RPs quickly associated with translating ribosomes in the cytoplasm and that this incorporation is independent of canonical ribosome biogenesis. Moreover, the incorporation probability of some RPs was regulated by location (neurites vs. cell bodies) and changes in the cellular environment (in response to oxidative stress). Our results suggest new mechanisms for the local activation, repair and/or specialization of the translational machinery within neuronal processes, potentially allowing remote neuronal synapses a rapid solution to the relatively slow and energy-demanding requirement of nuclear ribosome biogenesis.
Argonaute 2 (AGO2) is an indispensable component of the RNA-induced silencing complex, operating at the translational or posttranscriptional level. It is compartmentalized into structures such as GW- and P-bodies, stress granules and adherens junctions as well as the midbody. Here we show using immunofluorescence, image and bioinformatic analysis and cytogenetics that AGO2 also resides in membrane protrusions such as open- and close-ended tubes. The latter are cytokinetic bridges where AGO2 colocalizes at the midbody arms with cytoskeletal components such as α-Τubulin and Aurora B, and various kinases. AGO2, phosphorylated on serine 387, is located together with Dicer at the midbody ring in a manner dependent on p38 MAPK activity. We further show that AGO2 is stress sensitive and important to ensure the proper chromosome segregation and cytokinetic fidelity. We suggest that AGO2 is part of a regulatory mechanism triggered by cytokinetic stress to generate the appropriate micro-environment for local transcript homeostasis.