Ptbp1 and Exosc9 knockdowns trigger skin stability defects through different pathways

AbstractIn humans, genetic diseases affecting skin integrity (genodermatoses) are generally caused by mutations in a small number of genes that encode structural components of the dermal–epidermal junctions. In this article, we first show that inactivation of both exosc9, which encodes a component of the RNA exosome, and ptbp1, which encodes an RNA-binding protein abundant in Xenopus embryonic skin, impairs embryonic Xenopus skin development, with the appearance of dorsal blisters along the anterior part of the fin. However, histological and electron microscopy analyses revealed that the two phenotypes are distinct. Exosc9 morphants are characterized by an increase in the apical surface of the goblet cells, loss of adhesion between the sensorial and peridermal layers, and a decrease in the number of ciliated cells within the blisters. Ptbp1 morphants are characterized by an altered goblet cell morphology. Gene expression profiling by deep RNA sequencing showed that the expression of epidermal and genodermatosis-related genes is also differentially affected in the two morphants, indicating that alterations in post-transcriptional regulations can lead to skin developmental defects through different routes. Therefore, the developing larval epidermis of Xenopus will prove to be a useful model for dissecting the post-transcriptional regulatory network involved in skin development and stability with significant implications for human diseases

Caracterisation biochimique et purification de recepteurs au "basic Fibroblast Growth Factor" (bFGF) a partir de cerveaux de bovins adultes

SIGLEINIST T 74980 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Principes des techniques de biologie moléculaire et génomique3ième édition revue et augmentée

National audience"Cet ouvrage très didactique présente, sous forme de fiches, les principales techniques utilisées dans les laboratoires pour étudier le fonctionnement du vivant via les acides nucléiques. Après quelques définitions et généralités sur la structure des gènes, on y décrit les techniques de base en biologie moléculaire et génomique. Ces techniques consistent à extraire les acides nucléiques, à les découper, à récupérer des fragments d’intérêt et à les visualiser. Il s’agit également de les manipuler grâce aux techniques de clonage et de PCR (Polymerase Chain Reaction).Parmi les applications, le séquençage est une technique qui a grandement évolué ces quinze dernières années et qui n’est toujours pas stabilisée : nous aborderons ici les techniques de séquençage actuellement commercialisées et accessibles via des plateformes publiques ou privées.Autre application majeure, la manipulation des gènes par transformation génétique et mutagenèse permet une étude fine de leur fonctionnement. Plusieurs techniques de transformation génétique existent dont la nouvelle technique d’édition des génomes (CRISPR-Cas9) qui est décrite dans cet ouvrage.Enfin, la plupart des approches font maintenant appel à des stratégies dites « haut débit ». L’analyse des données ainsi générées nécessite de recourir à la bioanalyse et à la bioinformatique : cet ouvrage ne vise pas à donner toutes les bases de ces analyses, mais quelques applications y sont détaillées.Cette 3e édition revue et augmentée s’adresse aux étudiants et aux enseignants, ainsi qu’aux personnels travaillant dans des laboratoires manipulant les acides nucléiques.

Study of RNA-protein interactions and RNA structure in ribonucleoprotein particles (RNP).

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High Affinity Receptors to Acidic and Basic Fibroblast Growth Factor (FGF) are Detected Mainly in Adult Brain Membrane Preparations but not in Liver, Kidney, Intestine, Lung or Stomach

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Isolation of Basic FGF Receptors from Adult Bovine Brain Membranes

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Reassembling green fluorescent protein for in vitro evaluation of trans-translation

International audienceIn order to discover new antibiotics with improved activity and selectivity, we created a reliable in vitro reporter system to detect trans-translation activity, the main mechanism for recycling ribosomes stalled on problematic messenger RNA (mRNA) in bacteria. This system is based on an engineered tmRNA variant that reassembles the green fluorescent protein (GFP) when trans-translation is active. Our system is adapted for high-throughput screening of chemical compounds by fluorescence

Adult Brain but Not Kidney, Liver, Lung, Intestine, and Stomach Membrane Preparations Contain Detectable Amounts of High-Affinity Receptors to Acidic and Basic Growth Factors

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Implication of the SMN complex in the biogenesis and steady state level of the Signal Recognition Particle

International audienceSpinal muscular atrophy is a severe motor neuron disease caused by reduced levels of the ubiquitous Survival of MotoNeurons (SMN) protein. SMN is part of a complex that is essential for spliceosomal UsnRNP biogenesis. Signal recognition particle (SRP) is a ribonucleoprotein particle crucial for co-translational targeting of secretory and membrane proteins to the endoplasmic reticulum. SRP biogenesis is a nucleo-cytoplasmic multistep process in which the protein components, except SRP54, assemble with 7S RNA in the nucleolus. Then, SRP54 is incorporated after export of the pre-particle into the cytoplasm. The assembly factors necessary for SRP biogenesis remain to be identified. Here, we show that 7S RNA binds to purified SMN complexes in vitro and that SMN complexes associate with SRP in cellular extracts. We identified the RNA determinants required. Moreover, we report a specific reduction of 7S RNA levels in the spinal cord of SMN-deficient mice, and in a Schizosaccharomyces pombe strain carrying a temperature-degron allele of SMN. Additionally, microinjected antibodies directed against SMN or Gemin2 interfere with the association of SRP54 with 7S RNA in Xenopus laevis oocytes. Our data show that reduced levels of the SMN protein lead to defect in SRP steady-state level and describe the SMN complex as the first identified cellular factor required for SRP biogenesis