Characterization of dynamic profiles of the respiratory microbiota and host response from cystic fibrosis sputum samples

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Structural insights into protein–uranyl interaction: towards an in silico detection method

Documenting the modes of interaction of uranyl (UO 2 2+) with large biomolecules, and particularly with proteins, is instrumental for the interpretation of its behavior in vitro and in vivo. The gathering of three-dimensional information concerning uranyl-first shell atoms from two structural databases, the Cambridge Structural Databank and the Protein Data Bank (PDB) allowed a screening of corresponding topologies in proteins of known structure. In the computer-aided procedure, all potentially bound residues from the template structure were granted full flexibility using a rotamer library. The Amber force-field was used to loosen constraints and score each predicted site. Our algorithm was validated as a first stage through the recognition of existing experimental data in the PDB. The coherent localization of missing atoms in the density map of an ambiguous uranium/uranyl-protein complex exemplified the efficiency of our approach, which is currently suggesting the experimental investigation of uranyl-protein binding site

Insights into the respiratory microbiota of cystic fibrosis patients

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Espèces non-modèles, des espèces en voies de disparition en protéogénomique

International audiencePreviously, large-scale proteomics was possible only for organisms whose genomes were sequenced, meaning the most common model organisms. The use of next-generation sequencers is now changing the deal. With "proteogenomics", the use of experimental proteomics data to refine genome annotations, a higher integration of omics data is gaining ground. By extension, combining genomic and proteomic data is becoming routine in many research projects. "Proteogenomic"-flavored approaches are currently expanding, enabling the molecular studies of non-model organisms at an unprecedented depth. Today draft genomes can be obtained using next-generation sequencers in a rather straightforward way and at a reasonable cost for any organism. Unfinished genome sequences can be used to interpret tandem mass spectrometry proteomics data without the need for time-consuming genome annotation, and the use of RNA-seq to establish nucleotide sequences that are directly translated into protein sequences appears promising. There are, however, certain drawbacks that deserve further attention for RNA-seq to become more efficient. Here, we discuss the opportunities of working with non-model organisms, the proteomic methods that have been used until now, and the dramatic improvements proffered by proteogenomics. These put the distinction between model and non-model organisms in great danger, at least in terms of proteomics! BIOLOGICAL SIGNIFICANCE: Model organisms have been crucial for in-depth analysis of cellular and molecular processes of life. Focusing the efforts of thousands of researchers on the Escherichia coli bacterium, Saccharomyces cerevisiae yeast, Arabidopsis thaliana plant, Danio rerio fish and other models for which genetic manipulation was possible was certainly worthwhile in terms of fundamental and invaluable biological insights. Until recently, proteomics of non-model organisms was limited to tedious, homology-based techniques, but today draft genomes or RNA-seq data can be straightforwardly obtained using next-generation sequencers, allowing the establishment of a draft protein database for any organism. Thus, proteogenomics opens new perspectives for molecular studies of non-model organisms, although they are still difficult experimental organisms. This article is part of a Special Issue entitled: Proteomics of non-model organisms

Caractérisation haut-débit de la dynamique du protéome pour la découverte des protéines clefs chez les espèces sentinelles : une surprenante diversité des vitellogénines chez le crustacé Gammarus fossarum

International audienceIn environmental science,omics-based approaches arewidely used for the identification of gene products related to stress response. However,when dealingwith non-model species, functional prediction of genes is challenging. Indeed, functional predictions are often obtained by sequence similarity searches and functional data from phylogenetically distant organisms, which can lead to inaccurate predictions due to quite different evolutionary scenarios. In oviparous females, vitellogenin production is vital for embryonic development, ensuring population viability. Its abnormal presence in fish male organisms is commonly employed as a biomarker of exposure to xenoestrogens, named endocrine disruptors. Here, in the freshwater amphipod Gammarus fossarum, we identified vitellogenin proteins by means of a proteometemporal dynamics analysis during oogenesis and embryogenesis. This exhaustive approach allows several functional molecular hypotheses in the oogenesis process to be drawn. Moreover, we revealed an unsuspected diversity of molecular players involved in yolk formation as eight proteins originating from different families of the large lipid transfer protein superfamily were identified as “true vitellogenins”. Biological significance: In non-model species, next generation sequencing technologies development enables quickly deciphering gene and protein sequences but accuracy of associated functional prediction remains to be established. Here, in the crustacean Gammarus fossarum, a key sentinel species in freshwater biomonitoring, we identified key molecular players involved in the female reproduction by studying the proteome dynamics of ovaries and embryos. An unsuspected diversity of vitellogenin proteins was evidenced. These proteins being vital for offspring development, their high diversity may be advantageous for the organism's reproduction. Phylogenetic analysis showed that some forms are true vitellogenin orthologs while others are included in the apolipoprotein family, a paralogous group from the vitellogenin family. Among crustaceans, Gammarus fossarum is the first documented case where diverse protein families are involved in the yolk formation process

Caractérisation du microbiote pulmonaire de patients atteints de la mucoviscidose

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P084 Quick full-range determination of the composition of the cystic fibrosis lung microbiome from sputum by phylopeptidomics

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Deciphering the taxonomical and functional dynamics of the respiratory microbiota in CF patients colonized by NTM

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Caractérisation par la protéogénomique du core-protéome des tissus reproductifs femelles chez les crustacés amphipodes

International audienceAs a result of the poor genome sequence coverage of crustacean amphipods, characterization of their evolutionary biology relies mostly on phenotypic traits. Here, we analyzed the proteome of ovaries from five amphipods, all from the Senticaudata suborder, with the objective to obtain insights into the core-proteome of female reproductive systems. These amphipods were from either the Gammarida infraorder: Gammarus fossarum, Gammarus pulex, Gammarus roeseli, or the Talitrida infraorder: Parhyale hawaiensis and Hyalella azteca. Ovaries from animals sampled at the end of their reproductive cycle were dissected. Their whole protein contents were extracted and their proteomes were recorded by high-throughput nanoLC–MS/MS with a high-resolution mass spectrometer. We interpreted tandem mass spectrometry data with the protein sequence resource from G. fossarum and P. hawaiensis, both recently established by RNA sequencing. The large molecular biodiversity within amphipods was assessed by the ratio of MS/MS spectra assigned for each sample, which tends to diverge rapidly along the taxonomic level considered. The core-proteomewas defined as the proteins conserved along all samples, thus detectable by the homology-based proteomic assignment procedure. This specific subproteome may be further enriched in the future with the analysis of new species and update of the protein sequence resource