Développement d'un nouvel essai de complémentation protéique pour l'étude des interactions protéine-protéine : le PCA de la bêta-lactamase

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

STAR/GSG domain proteins bind to bipartite RNA motifs

Understanding the molecular biology of cells is a central field of research that is essential to all of the biological sciences. Messenger RNAs are the central link between DNA information contained in the nucleus and proteins that are synthesized in the cell cytoplasm. These mRNAs are subject to a substantial amount of modification and control, which are handled or under the supervision of RNA binding proteins. RNA binding proteins are trans-acting factors that interact with cis-acting elements present in the RNA sequence. They play major roles in mRNA processing including alternative splicing, translation, trafficking, localization and non-sense mediated decay. The STAR (signal tranduction activator of RNA metabolism) protein family are RNA binding proteins that can play multiple roles in RNA processing. This family of protein includes among others Quaking (QKI), SRC associated in mitosis (SAM68), SAM68-like mammalian protein 1 (SLM-1) and 2 (SLM-2), splicing factor 1 (SF1), germ-line development (GLD-1). All these family members contain a STAR/GSG domain that embeds a hnRNP K homology domain responsible for conferring the RNA binding properties. Because of the lack of genetic data providing insight about their physiological RNA targets, the function of these RNA binding proteins has been difficult to elucidate. Only a few mRNA targets are known across the whole family of STAR proteins. The hypothesis is that STAR proteins bind to a subset of determined mRNAs, and that identifying these RNAs and understanding how STAR proteins act on them would provide important evidence toward understanding the function of this familly of RNA binding proteins. Using systematic evolution of ligands by exponential enrichment (SELEX), we were able to define the QKI response element (QRE) as an hexanucleotide sequence (ACUAAY) with an additional half-site (UAAY). The identification of a refined QRE allowed us to perform a bioinformatic search which led us to the identification ofBien comprendre la biologie moléculaire de la cellule est un champ de recherche central et essentiel à toutes les sciences biologiques. L'ARN messager est le lien central entre l'information de l'ADN contenu dans le noyau cellulaire et les protéines traduits dans le cytoplasme des cellules. Ces ARN messagers sont sujets à une quantité importante de modifications et de contrôle par des protéines liant l'ARN. Ces protéines jouent plusieurs rôles majeurs dans la maturation des ARN messagers incluant l'épissage alternatif, la traduction, le transport, la localisation ainsi que la dégénérescence d'ARN non-sens. La famille de protéine STAR « Signal Transduction and Activatior of RNA metabolism » sont des protéines liant l'ARN capable de jouer plusieurs rôles dans la maturation des ARNs. Cette famille de protéine comprend Quaking, SAM68, SLM-1, -2, SF1, GLD-1 et plusieurs autres. Tous les membres de cette famille ont au sein de leur structure un domaine STAR/GSG comprenant un plus petit domaine homologue à celui de hnRNP K conférant les propriétés de liaison à l'ARN. Les rôles exactes de cette famille de protéine sont encore difficiles à identifier étant donné le manque de donnés génétiques sur les cibles d'ARN messagers physiologiques dont nous avons en notre possession. En fait, seulement quelques cibles d'ARN messagers ont été identifiées au sein de toute la famille de protéine STAR. L'hypothèse derrière cette étude est que les protéines STAR s'associent avec certains ARN messagers définis et que l'identification de ces ARN messagers et la compréhension sur la façon dont les protéines STAR agissent sur ces derniers fournira des informations pertinentes quant à l'identification exacte du rôle que cette famille de protéines joue dans la cellule. En utilisant une technique de biologie moléculaire appelé SELEX « Systematic Evolution of Ligand by EXponential enrichment », nous avons pu identifier l'élément de réponse

Ionic Liquid Mediated Sol-Gel Synthesis in the Presence of Water or Formic Acid: Which Synthesis for Which Material?

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Zur Entstehung der kanadischen Varietät des Französischen

Zur Entstehung der kanadischen Varietät des Französischen. - In: Politik in Nordamerika und Europa : Analysen, Theorien und literarische Rezeption / Jan Grasnick ... (Hrsg.). - Wiesbaden : Springer VS, 2012. - S. 130-13

Advances in design and modeling of porous materials

This special issue of the European Physical Journal Special Topics is dedicated to selected papers from the symposium “High surface area porous and granular materials” organized in the frame of the conference “Matériaux 2014”, held on November 24–28, 2014 in Montpellier, France. Porous materials and granular materials gather a wide variety of heterogeneous, isotropic or anisotropic media made of inorganic, organic or hybrid solid skeletons, with open or closed porosity, and pore sizes ranging from the centimeter scale to the sub-nanometer scale. Their technological and industrial applications cover numerous areas from building and civil engineering to microelectronics, including also metallurgy, chemistry, health, waste water and gas effluent treatment. Many emerging processes related to environmental protection and sustainable development also rely on this class of materials. Their functional properties are related to specific transfer mechanisms (matter, heat, radiation, electrical charge), to pore surface chemistry (exchange, adsorption, heterogeneous catalysis) and to retention inside confined volumes (storage, separation, exchange, controlled release). The development of innovative synthesis, shaping, characterization and modeling approaches enables the design of advanced materials with enhanced functional performance. The papers collected in this special issue offer a good overview of the state-of-the-art and science of these complex media. We would like to thank all the speakers and participants for their contribution to the success of the symposium. We also express our gratitude to the organization committee of “Mat´eriaux 2014”. We finally thank the reviewers and the staff of the European Physical Journal Special Topics who made the publication of this special issue possible

Advances in design and modelling of porous materials

International audienc