Dissertations / Theses on the topic 'Interactions protéine-protéine – Identification'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 32 dissertations / theses for your research on the topic 'Interactions protéine-protéine – Identification.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Moine-Franel, Alexandra. "Cartographie des poches aux interfaces protéine-protéine et identification de nouvelles cibles thérapeutiques potentielles." Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS634.pdf.
Protein-protein interactions (PPIs) constitute a significant source of potential therapeutic targets because they play a crucial role in numerous and diverse biological processes, including the development of pathologies. While PPIs appear as promising therapeutic targets, they are more challenging to study than conventional therapeutic targets. Indeed, known PPIs are characterized by specific structural motifs that limit their ‘druggability’, meaning their ability to bind to and be modulated by a small drug molecule. However, the growing identification of small molecules modulating various PPIs demonstrates that, with an appropriate methodology, they can represent a class of novel and innovative therapeutic targets. The objective is, therefore, to develop an in silico protocol to aid in identifying new therapeutic targets involving PPIs by rationalizing the key elements that determine the ‘druggability’ of the interaction
Douguet, Dominique. "Etude des interactions protéine-protéine et protéine-ligand par bio- et chimie-informatique structurale : Identification de petites molécules bio-actives." Habilitation à diriger des recherches, Université de Nice Sophia-Antipolis, 2007. http://tel.archives-ouvertes.fr/tel-00320089.
La modélisation par homologie permet d'obtenir un modèle tridimensionnel d'une protéine lorsque sa structure n'a pas été déterminée expérimentalement. Ma contribution dans ce domaine fut la réalisation du serveur @TOME avec le soutien de la GENOPOLE Languedoc-Roussillon (accessible à l'adresse http://bioserver.cbs.cnrs.fr). Ce serveur était le premier de ce type à avoir été développé en France. Le serveur @TOME rassemble et traite d'une manière automatique toutes les étapes nécessaires à la construction d'un modèle 3D d'une protéine. Cela inclut la reconnaissance du repliement, la construction des modèles protéiques et leur évaluation. Les résultats du CASP5 en 2005 (session internationale d'évaluation des méthodes de prédiction de la structure des protéines ; http://predictioncenter.llnl.gov/) ont montré que notre serveur utilisé en mode automatique propose des modèles très proches de la structure expérimentale lorsque l'identité de séquence avec la structure support est supérieure à 30%. Le serveur a été classé 26ième sur 187 groupes inscrits.
Dans un second temps, mes recherches m'ont permis de réaliser une base de données de complexes protéiques co-cristallisés, base fondatrice du projet DOCKGROUND. Ce projet de grande envergure, soutenu par le NIH depuis 2005, vise à établir un système intégré et dynamique de bases de données dédié à l'étude et à la prédiction des interactions entre protéines et permettre ainsi d'améliorer nos connaissances des interactions et de développer des outils de prédiction plus fiables. Ce travail a été effectué au sein de l'équipe du Pr. Ilya Vakser à l'Université de Stony Brook, NY, USA. Dans la réalisation de cette première base de données, un ensemble de programmes collectent, classent et annotent les complexes protéiques qui ont été co-cristallisés (données sur la séquence, la fonction, le repliement 3D, les particularités telles qu'une fixation à de l'ADN, ...). Ensuite, j'ai mis en œuvre une sélection dynamique des représentants des complexes contenus dans cette base. Les représentants sont essentiels pour éviter une surreprésentation de certaines familles de protéines. Cette base de donnée est accessible par Internet et est régulièrement mise à jour (http://dockground.bioinformatics.ku.edu). Le projet DOCKGROUND va être poursuivi par la réalisation de 3 autres bases de données qui s'ancreront sur la présente appelée ‘Bound-Bound'.
L'objectif principal de mes travaux est d'identifier de nouveaux composés bio-actifs afin de comprendre le fonctionnement de leur cible dans un contexte biologique. Les méthodes que j'utilise se basent sur la chémoinformatique, le criblage virtuel et le de novo ‘drug design'. Dans le cadre de ce dernier, j'ai mis au point un programme propriétaire LEA3D (‘Ligand by Evolutionary Algorithm' 3D). Le programme génère des petites molécules à partir de la combinaison de fragments moléculaires issus de drogues et de molécules ‘bio' (substrats ou produits de réactions enzymatiques). Le criblage virtuel basé sur la structure protéique et le de novo ‘drug design' par LEA3D, ont été appliqués avec succès à la thymidine monophosphate kinase (TMPK) de Mycobacterium tuberculosis dans le cadre d'une collaboration avec une équipe de chimistes et de biologistes de l'Institut Pasteur. De nouvelles familles d'inhibiteurs ont été identifiées dont un inhibiteur synthétique trois fois plus affin que le substrat naturel. Plusieurs publications et une demande de brevet couvrent les résultats de ces recherches. Dans la continuité de ces travaux, je m'intéresse maintenant, plus particulièrement, à développer des stratégies de criblages de fragments (molécules de petit poids moléculaire). Il a été montré que de petites chimiothèques contenant des petites molécules polaires sont plus efficaces pour identifier des touches. Ce travail doit être réalisé conjointement avec des criblages structuraux expérimentaux comme la RMN ou la diffraction des rayons X. Ces derniers se posent comme une alternative aux tests in vitro avec pour avantage de donner une information détaillée, au niveau atomique, des interactions entre le ligand et sa cible. S'ensuit une étape d'optimisation/maturation des touches en ligands plus élaborés et plus affins par l'utilisation d'outils de chémoinformatique.
Corsi, Flavia. "Towards the in silico reconstruction of protein interaction networks : identification of DNA- and RNA-protein interfaces, and construction of a database of multiple interactions of proteins." Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS452.pdf.
This thesis focuses on the characterization and prediction of DNA- and RNA-binding sites on protein structures, with some comparisons with protein-protein ones. We compiled and manually curated a non-redundant and representative set of 187 high resolution protein-DNA complexes, with the available 82 protein unbound conformations, that could be used as a reference benchmark. We conducted a comprehensive analysis of sequence- and structure-based properties of protein-DNA/RNA interfaces and compared them with respect to protein-protein interfaces and to non-interacting protein regions. We developed JET2DNA and JET2RNA, new methods for predicting DNA- and RNA-binding sites on protein surfaces. Combining four biologically meaningful descriptors, they outperform other machine-learning methods, in terms of predictive power and robustness to conformational changes. Our tools demonstrated to be instrumental in discovering alternative DNA/RNA-binding sites and in deciphering their properties. This could be very helpful for drug design and repurposing. To give a comprehensive view of plasticity of DNA-binding proteins and structural information on their multiple interactions, we constructed the Protein-(Protein)-DNA database (P(P)DNAdb). It comprises the 187 protein-DNA complexes in our benchmark, protein unbound forms and structures of other complexes where the proteins, or closed homologs, were in contact with other proteins. The user can access properties of the interfaces, visualize conformational changes associated to the binding of different partners and the location of the DNA-binding residues on the unbound structures and on the complexes with the other protein partners
Fradin, Aurelie. "Identification des modifications post-traductionnelles d'Ilf3 (Interleukin enhancer binding factor 3) et de NF90 (Nuclear Factor 90) et étude de leur rôle(s) fonctionnel(s)." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066222/document.
Ilf3 and NF90, two double stranded RNA-binding proteins, are generated by exclusive splicing from the ILF3 gene. For each one, a 5? alternative splicing leads to the synthesis of a long and a short isoforms that differ by the presence or not of 13 amino acid sequence at their N-terminus corresponding to a nucleolar localization signal. The characteristic of these two proteins is to exhibit a high degree of heterogeneity with at least 20 isoforms produced from the same gene, 12 for Ilf3 and 8 for NF90. It is generated by two complementary mechanisms, alternative splicing and posttranslational modifications which two have been identified in the laboratory, the arginine 609/622 asymmetric dimethylation present in a RGG consensus sequence and catalyzed by PRMT1 ("protein arginine N-methyltransferase 1") and the serine 190/203 phosphorylation. This polymorphism could explain the various cellular functions described for both proteins and could regulate their subcellular localization and the interaction with protein or nucleic partners. By immunofluorescence and GST pull-down experiments, it was shown that these two posttranslational modifications of Ilf3 and NF90 neither seem involved in their subcellular localization, nor in the regulation of interactions with their protein partners. Because of the many functions associated with Ilf3 and NF90 proteins in the literature, the identified modifications may be implicated in regulating the interactions with their nucleic partners, DNA or RNA
Viard, Julia. "Identification et manipulation d’interactions protéines - protéines codées par des gènes impliqués dans des synaptopathies." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLE033.
Many neurodevelopmental diseases have a complex genetic architecture involving several deregulated genes and are characterized by synaptic perturbations. In order to explore how these various genetic alterations result in synaptic phenotypes, we analysed protein - protein interactions encoded by these different genes leading us to identify novel deregulated molecular pathways at the synapse.This work focussed on two different synaptopathies, the intellectual disability in Down syndrome and cognitive impairment and autism caused by the structural changes in the AUTS2 gene.First, we performed a large-scale study of the interactions of the proteins encoded by the chromosome 21, using yeast two-hybrid, and identified a network of synaptic protein which is enriched in genes involved in intellectual disability. We also highlighted nuclear interactions that are disrupted in a mouse model overexpressing DYRK1A and impair a NMDA-independent Long-Term Potentiation (LTP) synaptic plasticity phenotype.Then, we characterized the mechanistic of the gene dosage alteration of AUTS2 involved in autism and intellectual disability. We have identified a complex between AUTS2 and TTC3, the E3 ligase of AKT mediating the ubiquitination of Akt at the synapse. We managed to rescue the synaptic phenotype induced by the silencing of AUTS2 by injection of AKT and generated two mouse models displaying either duplication or deletion of the AUTS2 locus (~1Mb). These mouse models display synaptic defects.In conclusion, this work shows the relevance of studying protein interactions to understand the mechanistic consequences of multigene disturbances observed at the synapses in these diseases
Bachiri, Kamel. "Identification des interactions oncogéniques du Polyomavirus à cellules de Merkel." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILS113.
Merkel cell carcinoma (MCC) is an extremely aggressive skin cancer with a high mortality rate. In 80% of cases, this cancer is linked to the presence of the Merkel cell polyomavirus which expresses two viral oncoproteins, small T and a truncated form of large T. The expression of these proteins is sufficient for carcinogenesis, inducing the disruption of cell cycle checkpoints, changes in the epigenetic profile, and immune evasion. The combination of interactomics and proteomics approaches allowed us to identify numerous epigenetic factors related to the T antigens. These studies have also highlighted potential mechanisms involving the regulation of protein stability, gene expression, and genetic stability via an altered DNA damage response pathway. The hypotheses formulated following these analyses were investigated in targeted assays. A link between the peptidyl-prolyl cis/trans isomerase and neddylation was demonstrated. We have thus identified a new potential mechanism for regulating the activity of ubiquitination complexes involving the recruitment of PIN1 to these complexes, thus their isomerization, by neddylation. The study of the EHMT2 functions, an epigenetic regulator of interest, revealed the importance of its role in the DNA damage response in virus positive MCC (VP-MCC). We were able to identify a protective role of tLT and EHMT2 in DNA damages in VP-MCC cells. More specifically, we also report a role of EHMT2 in solving single strand DNA breaks following replication stress. Our works have enabled the discovery of new important mechanisms in VP-MCC oncogenesis, reporting for the first time a central role of tLT in DNA damages management
Ben, Salah Iskandar. "Les mycobactéries du complexe Mycobacterium avium : identification et interactions avec les amibes libres." Aix-Marseille 2, 2009. http://www.theses.fr/2009AIX20682.
Verreman, Kathye. "Identification et caractérisation de nouveaux partenaires du facteur de transcription ERM." Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10057/document.
ERM is an ETS transcription factor which belongs to the PEA3 group and is involved in several processes such as migration and dissemination during organogenesis and cancer development. Regulation of its transcriptional activity requires post-translational modifications and interactions with partner proteins. In order to identify new ERM partners, we have developed various affinity chromatography techniques to isolate new potential partners. Among these candidates, CoAA (CoActivator Activator), MED23 and MED25 directly interact with ERM.MED23 and MED25 are subunits of the mediator. The mediator is a 30 sub-units multi-protein complex which mediates signals from transcription factors bound at upstream promoter elements or enhancers to RNA polymerase II and the general initiation factors bound at the core promoter. We found that MED23 and MED25 interact with ERM in vitro and in vivo and are required for transcriptional activation induced by ERM. However, these sub-units display various ability to recruit the mediator on ERM in vitro. The heterogeneous nuclear ribonucleoprotein-like protein CoAA regulates gene expression and RNA splicing. We demonstrated that ERM interacts in vitro and in vivo with CoAA. ERM transcriptional activity is enhanced upon CoAA overexpression and is decreased by CoAA knock-down. We demonstrated that CoAA modulates ERM transcriptional activity by decreasing sumoylated ERM levels. This work demonstrated new ways to regulate the activity of ERM and the two other PEA3 group members. The molecular mechanisms involved in the modulation of PEA3 member activity by these partners remain to be clarified
Michaux, Charlotte. "Identification et caractérisation fonctionnelle de petits ARN non codants chez Enterococcus faecalis et analyse d'une protéine "RNA-binding"." Caen, 2013. http://www.theses.fr/2013CAEN2094.
Tahir, Shifa. "A docking-based method for in silico epitope determination." Thesis, Tours, 2018. http://www.theses.fr/2018TOUR4008.
The development of therapeutic antibodies has been rapidly increasing in the last 10 years, with application to an increasing number of pathologies. The knowledge of the epitope, the region of the antigen to which the antibody binds, is crucial for understanding its functional effects. We have developed an in silico method, MAbTope, which allows the accurate prediction of the epitope, regardless of the availability of the 3D structure of the antibody of interest. This method is based on a protein-protein docking method previously developed in the BIOS group. The learning dataset was enlarged in antibody-antigen complexes, new specific scoring functions have been designed, and very importantly, the objective of machine-learning was switched from the conformational perspective towards the epitope determination perspective. We show that the resulting method allows robust and accurate prediction, whether or not the 3D structure of the antibody is available. We also show how the predictions can be easily exploited for experimental validation. Finally, we show how this method can be used for high-throughput epitope binning
Guermann, Benoît. "Identification et étude fonctionnelle d'une famille de proréines mitochondriales à motif RRM chez les plantes supérieures." Université Louis Pasteur (Strasbourg) (1971-2008), 2004. http://www.theses.fr/2004STR13084.
Choul-Li, Souhaila. "Le facteur de transcription Ets-1 : identification de nouveaux partenaires protéiques et étude du clivage par les caspases." Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10099/document.
Ets-1 is a transcription factor that regulates genes involved in various physiological and pathological processes. Ets-1 proteins do not act alone on their target promoters but with a wide range of protein partners. Identifying novel proteins that interact with Ets-1 should permit a better understanding of the intrinsic functions of the Ets-1 proteins. For this purpose, we develop an affinity purification strategy of Ets-1 interaction partners using streptavidin pull-down assay. We thereby identified new potentials interaction partners consisting for a heterotrimeric complex of DNA-PK, made up of Ku70, Ku86 and DNA-PKcs. Then, we characterized the functional consequences of the interactions. These results have permit to identify a new regulation of its activity that could provide new clues to understand the diverse functions of Ets-1.In another study, we demonstrated that the majority isoform Ets-1 p51 is a novel cleavage substrate of caspase-3, an effector protease of apoptosis. Indeed, Ets-1 p51, but not the spliced variant Ets-1 p42, is processed in vitro and in cells undergoing apoptosis by caspase-3. These cleavages lead to the generation of three C-terminal fragments Cp20, Cp17 and Cp14 and a N-terminal fragment, Np36. The Cp17 fragment, the major cleavage product generated during apoptosis, inhibits Ets-1 p51-mediated transactivation of target genes, acting thus as a natural dominant-negative of the full-length Ets-1 p51 protein. These data suggest a novel mechanism of Ets-1 p51 regulation through its caspase-mediated cleavages and generation of a dominant-negative fragment, which may play active role during apoptosis
Bichraoui, Hicham. "Identification de nouveaux déterminants moléculaires de l'interaction du récepteur des dihydropyridines avec le récepteur à la ryanodine." Université Joseph Fourier (Grenoble), 2010. https://tel.archives-ouvertes.fr/tel-00615499.
In skeletal muscle, the action potential triggers muscle contraction through a massive calcium release from the sarcoplasmic reticulum (SR). This process, called excitation-contraction coupling (ECC), requires physical interactions between two calcium channels: (1) the dihydropyridine receptor (DHPR), a voltage-dependent channel composed of four subunits among which the α1S subunit, that forms both the pore and the voltage-sensor, and the ß1a subunit fully cytoplasmic, and (2) the ryanodine receptor (RyR1) which is responsible of calcium release from SR. ß1a subunit interacts with both RyRl and the α1S subunit. The mechanism whereby the DHPR is functionally coupled to RyR1 is still not clearly understood. During my thesis, I identified new molecular and structural determinants of the interaction between RyR and DHPR. I demonstrated the existence of intramolecular interactions between the cytoplasmic loops of the α1S subunit centered on a domain called domain A. I also localized the site of interaction of the caveoline-3 on the 1-11 loop of al S. The study of the interaction of the ßla subunit with RyR1 showed (1) that the C-terminal region of ß1a controls this interaction, (2) that the affinity of this interaction is strongly increased by the interaction of ß1a with α1S, and 3) that the interaction ß1a/RyR1 regulates the closure of RyR1. The use of a toxin, the maurocalcine (MCa) which behaves as an analogue of the domain A allowed me to identify a minimal domain of RyR1 responsible for the binding of the MCa and the domain A. A structural study by NMR of this domain has been realized. Finally, I studied the effect of the MCa on myotubes not expressing the α1S sub-unit. I showed that the MCa is capable of restoring in absence of DHPR, an increase of the cytoplasmic Ca2+ concentration triggered by the depolarization of the plasma membrane
Bichraoui, Hicham. "Identification de nouveaux déterminants moléculaires de l'interaction du récepteur des dihydropyridines avec le récepteur à la ryanodine." Grenoble 1, 2010. http://www.theses.fr/2010GRENV025.
In skeletal muscle, the action potential triggers muscle contraction through a massive calcium release from the sarcoplasmic reticulum (SR). This process, called excitation-contraction coupling (ECC), requires physical interactions between two calcium channels: (1) the dihydropyridine receptor (DHPR), a voltage-dependent channel composed of four subunits among which the α1S subunit, that forms both the pore and the voltage-sensor, and the ß1a subunit fully cytoplasmic, and (2) the ryanodine receptor (RyR1) which is responsible of calcium release from SR. ß1a subunit interacts with both RyRl and the α1S subunit. The mechanism whereby the DHPR is functionally coupled to RyR1 is still not clearly understood. During my thesis, I identified new molecular and structural determinants of the interaction between RyR and DHPR. I demonstrated the existence of intramolecular interactions between the cytoplasmic loops of the α1S subunit centered on a domain called domain A. I also localized the site of interaction of the caveoline-3 on the 1-11 loop of al S. The study of the interaction of the ßla subunit with RyR1 showed (1) that the C-terminal region of ß1a controls this interaction, (2) that the affinity of this interaction is strongly increased by the interaction of ß1a with α1S, and 3) that the interaction ß1a/RyR1 regulates the closure of RyR1. The use of a toxin, the maurocalcine (MCa) which behaves as an analogue of the domain A allowed me to identify a minimal domain of RyR1 responsible for the binding of the MCa and the domain A. A structural study by NMR of this domain has been realized. Finally, I studied the effect of the MCa on myotubes not expressing the α1S sub-unit. I showed that the MCa is capable of restoring in absence of DHPR, an increase of the cytoplasmic Ca2+ concentration triggered by the depolarization of the plasma membrane
Cossé, Mathilde. "Identification et caractérisation d'un nouvel effecteur précoce de Chlamydia trachomatis." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066083/document.
C. trachomatis is an obligate intracellular Gram-negative bacteria and a human pathogen. It is the most prevalent cause of sexually transmitted diseases of bacterial origin and a leading cause of preventable blindness in the developing world. During their biphasic developmental cycle the bacteria remains in a membrane-bounded cellular compartment called an inclusion. Using a type 3 secretion system (T3SS) they translocate effector proteins inside the cytosol of the cell to promote its survival and multiplication.The aim of the PhD was to study the function of CT622, a hypothetic protein from C. trachomatis. We showed that CT622 is an effector protein from the T3SS and that it is secreted early during the infection. We identified a bacterial protein that binds to CT622, and we showed that it acts as a chaperone, stabilizing CT622 and enhancing its secretion. We obtained bacteria lacking CT622 expression, thus demonstrating that CT622 is not essential for bacterial growth in vitro. However, preliminary studies indicate that in the absence of CT622 bacterial development is delayed and T3SS is defective.We identified several molecules interacting with CT622: geranylgeranyl diphosphate, Rab39 and Atg16L1 proteins. Future work will aim at understanding how these identified interactions, or other bacterial or cellular partners still to be discovered, contribute to the establishment of a niche favorable to bacterial development
Desjobert, Cécile. "L'intégrase du virus de l'immunodéficience humaine de type 1 : identification de ligands protéiques et peptidiques : étude de ces interactions physiques et fonctionnelles." Bordeaux 2, 2005. http://www.theses.fr/2005BOR21204.
AIDS is a worldwide health problem. Integrase (IN) catalyzes a crucial step of the HIV-1 infectious cycle : integration of the viral DNA into the cellular genome. So IN is an attractive target which is not yet used in current therapies. Moreover the retroviral IN interacts with other factors in a preintegration complex (PIC) that optimizes its activities in the nucleus. These partners are not all identified and their action on IN is not well understood. We studied the interactions between IN and RT because these two viral enzymes are present in the PIC and their activities are mutually regulated during the viral cycle. Using ELISA and pull-down, we demonstrated the interaction between the two enzymes. Therefore RT is able to inhibit IN activities at a ratio of 1 : 1. To isolate cellular partners of IN we used the yeast-two hybrid system. We identified microtubule-associated proteins, suggesting a role of this network in the transport of IN to the nucleus. Finally, phage-display method was used to screen random heptapeptides ligands of IN. One of them was found to be an efficient inhibitor of its strand transfer reaction. This peptide could be used as a base for developing new anti-integrase compounds
Cossé, Mathilde. "Identification et caractérisation d'un nouvel effecteur précoce de Chlamydia trachomatis." Electronic Thesis or Diss., Paris 6, 2016. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2016PA066083.pdf.
C. trachomatis is an obligate intracellular Gram-negative bacteria and a human pathogen. It is the most prevalent cause of sexually transmitted diseases of bacterial origin and a leading cause of preventable blindness in the developing world. During their biphasic developmental cycle the bacteria remains in a membrane-bounded cellular compartment called an inclusion. Using a type 3 secretion system (T3SS) they translocate effector proteins inside the cytosol of the cell to promote its survival and multiplication.The aim of the PhD was to study the function of CT622, a hypothetic protein from C. trachomatis. We showed that CT622 is an effector protein from the T3SS and that it is secreted early during the infection. We identified a bacterial protein that binds to CT622, and we showed that it acts as a chaperone, stabilizing CT622 and enhancing its secretion. We obtained bacteria lacking CT622 expression, thus demonstrating that CT622 is not essential for bacterial growth in vitro. However, preliminary studies indicate that in the absence of CT622 bacterial development is delayed and T3SS is defective.We identified several molecules interacting with CT622: geranylgeranyl diphosphate, Rab39 and Atg16L1 proteins. Future work will aim at understanding how these identified interactions, or other bacterial or cellular partners still to be discovered, contribute to the establishment of a niche favorable to bacterial development
Bichraoui, Hicham. "IDENTIFICATION DE NOUVEAUX DETERMINANTS MOLECULAIRES DE L'INTERACTION DU RECEPTEUR DES DIHYDROPYRIDINES AVEC LE RECEPTEUR A LA RYANODINE." Phd thesis, Université de Grenoble, 2010. http://tel.archives-ouvertes.fr/tel-00615499.
Mendes, Tiago. "Identification of the modulators of and the molecular pathways involved in the BIN1-Tau interaction." Thesis, Lille 2, 2018. http://www.theses.fr/2018LIL2S033/document.
The main neuropathological hallmarks of Alzheimer’s disease (AD) are the extracellular senile plaques composed of amyloid-β peptide (Aβ) and the intracellular neurofibrillary tangles composed of hyperphosphorylated Tau. The mechanisms leading to the formation of these lesions is not well understood and our lab has recently characterized the bridging integrator 1 (BIN1) gene, the second most associated genetic risk factor of AD and the first genetic risk factor to have a potential link to Tau pathology. The interaction between BIN1 and Tau proteins has been described in vitro and in vivo, which suggests that BIN1 might help us to understand Tau pathology in the context of AD. However, the role of BIN1-Tau interaction in the pathophysiological process of AD is not known, and whether this interaction is a potential therapeutic target remains to be determined. The aim of this project is to better understand the actors of BIN1-Tau interaction through the identification of the modulators and the molecular pathways involved therein, as well as to understand how BIN1-Tau interaction is modulated in the context of AD. We employed biochemistry, nuclear magnetic resonance, and confocal microscopy. We used rat primary neuronal cultures (PNC) as the cellular model and developed the proximity ligation assay (PLA) as the main readout of the BIN1-Tau interaction in cultured neurons. We determined that the interaction occurs between BIN1’s SH3 domain and Tau’s PRD domain, and demonstrated that it is modulated by Tau and BIN1 phosphorylation: phosphorylation of Tau at Threonine 231 decreases its interaction with BIN1, while phosphorylation of BIN1 at Threonine 348 (T348) increases its interaction with Tau. We developed a novel, semi-automated high content screening (HCS) assay based on a commercial compound library, also using PNC as the cellular model and PLA as the readout of BIN1-Tau interaction. We identified several compounds that are able to modulate the BIN1-Tau interaction, most notably U0126, an inhibitor of MEK-1/2, which reduced the interaction, and Cyclosporin A, an inhibitor of Calcineurin, which increased the interaction through increasing the BIN1 phosphorylation at T348. Furthermore, Cyclin-dependent kinases (CDK) were also shown as regulator of this phosphorylation site. These results suggest that the couple Calcineurin/CDK regulates BIN1 phosphorylation at T348 and consequently the BIN1-Tau interaction. We also developed a mouse model of tauopathy in which we overexpressed human BIN1. We observed that the overexpression of BIN1 rescued the long-term memory deficits and reduced the presence of intracellular inclusions of phosphorylated Tau, caused by Tau overexpression, and this was associated with an increase of BIN1-Tau interaction. Also, using post-mortem human brain samples, we observed that the levels of the neuronal BIN1 isoform were decreased in AD brains, whereas the relative levels of BIN1 phosphorylated at T348 were increased, suggesting a compensatory mechanism. Altogether, this study demonstrated the complexity and the dynamics of BIN1-Tau interaction in neurons, revealed modulators of and molecular pathways potentially involved in this interaction, and showed that variations in BIN1 expression or activity have direct effects on learning and memory, possibly linked to the regulation of its interaction with Tau
Fournel, Tutik. "Production of recombinant E6 protein of HPV type 16 responsible for cervical cancers : identification and characterization of specific interaction between E6 protein and four-way DNA junctions." Université Louis Pasteur (Strasbourg) (1971-2008), 2001. http://www.theses.fr/2001STR13171.
Lussier, Marc. "Identification et caractérisation de nouveaux partenaires d'intéraction liant le domaine de répétitions similaires à l'ankyrine des TRPCs." Thèse, Université de Sherbrooke, 2008. http://savoirs.usherbrooke.ca/handle/11143/4261.
Martin, Sophie. "Le composant des granules de stress G3BP : caractérisation phénotypique de souris KO, et identification de son interactome ribonucléoprotéique dans le cerveau de souris." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20247.
RNA binding proteins (RBPs) are essential in the different steps of processing of the messenger RNAs (mRNAs), directing their localization and fate within the cell, and forming with them the ribonucleoprotein particles (mRNPs). mRNPs can assemble into dynamic cellular structures in which they are routed towards specific functions. RNA granules such as stress granules (SGs) contain translationally silenced mRNPs storing transiently repressed mRNAs.My thesis work consisted in the functional characterization of G3BP (RasGAP SH3 binding protein), an RBP that is expressed ubiquitously in both humans and mice and is involved in the assembly of SGs. Using classical homozygous recombination, viable G3BP1 knock out mice were generated that demonstrated short lifespan.and behavioral defects linked to the Central Nervous System (CNS), notably an ataxia phenotype. Electrophysiology experiments showed an alteration of synaptic plasticity in the hippocampus of KO mice. Therefore, I used Cross-Linking and Immunoprecipitation (CLIP) to purify from mouse brain a stable complex containing G3BP, and performed High-Throughput Sequencing (HITS-CLIP) to identify associated RNAs. Strikingly, most of the G3BP targets correspond to intron sequence-retaining transcripts and non-coding RNAs. My results also showed that G3BP1 depletion influences the stability of these premature transcripts in the cerebellum, which can be correlated to the ataxia phenotype of the G3BP1 KO mice. This comprehensive analysis suggests a new mechanism of gene regulation based on stabilization of silenced premature transcripts which might be converted to mature transcripts under stress condition and sequestration of G3BP in SGs
Mirouze, Nicolas. "Identification du produit d'un gène tardif impliqué dans la régulation de la compétence et dans le processing de l'ADN lors de la transformation naturelle chez S. Pneumoniae." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/144/.
Streptococcus pneumoniae is a gram positive human pathogen bacterium. Worldwide, it kills millions of people each year. Historically, it's one of the first model bacterium used in microbiology. For example, transformation was revealing for the first time in S. Pneumoniae. The natural transformation represents the capacity of certain bacteria to be got of exogenous DNA from the medium, to admit it in their cytoplasm to finally integrate it into their genome. All the machineries necessary for the development of transformation are organized only if the cells develop a particular physiological state named competence. The competence (com) regulon is controlled by a complexe network. The com regulon is made of two classes of gene, so-called early and late. The former class relies on ComE (presumably ComE-P) for expression while the latter depends on ComX. We were particularly interested in this study about the DprA protein, encoded by a late gene to which several drastic phenotypes are associated in S. Pneumoniae. This multi-functional protein is effectively associated to several processes as the protection of transforming DNA between its entry in the cell to the RecA-dependant homologous recombination or the shutoff of competence by inhibiting the activity of two major regulatory proteins, ComE and ComX. The existence of a such protein (which is conserved in all the transformable bacteria) strengthen the links which exist between competence and transformation
Avet, Charlotte. "Étude des mécanismes contrôlant l'efficacité et la spécificité de la signalisation du récepteur de la GnRH : identification et rôle de la protéine partenaire SET." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA11T091.
Reproductive function is under the control of the hypothalamic neurohormone GnRH, which regulates the synthesis and the release of pituitary gonadotropins. GnRH acts on a G-protein coupled receptor expressed at the surface of pituitary gonadotrope cells, the GnRH receptor (GnRHR). This receptor, in mammals, is unique because it is devoided of the C terminal tail, which makes it insensitive to classical desensitization processes. Therefore, the mechanisms that regulate the efficacy and the specificity of its signaling are still poorly known. We searched for interacting partners of GnRHR with the idea that these proteins by interacting with the intracellular domains of the receptor could influence receptor coupling to its signaling pathways. Our work identified the first interacting partner of GnRHR: the protein SET. By GST pull down assays, we showed that SET interacts directly with GnRHR through the first intracellular loop of the receptor. This interaction involves sequences enriched in basic amino acids in the receptor and both N- and C terminal domains of SET. We also showed, by co-immunoprecipitation, that GnRHR in its native conformation interacts with the endogenous SET protein in gonadotrope alphaT3-1 cells and, by immunocytochemistry that the two proteins colocalize at the plasma membrane. By developing in the laboratory biosensors tools that allow to measure with high sensitivity and in real-time intracellular variations in calcium and cAMP concentrations, we demonstrated that GnRHR couples not only to the calcium pathway but also to the cAMP pathway in alphaT3-1 cell line, providing for cAMP the first demonstration of such coupling. Using several experimental strategies to reduce or increase receptor interaction with SET (small interfering RNA, peptide corresponding to the first intracellular loop of the receptor, overexpression of SET), we have shown that SET induces a switch of GnRHR signaling from calcium to cAMP pathway. Our results concerning the activity of the Gnrhr gene promoter led us to postulate that SET could favor the induction by GnRH of genes regulated through the cAMP pathway, notably those encoding the GnRHR. Our study also showed that GnRH regulates not only SET protein expression in gonadotropes, but also its phosphorylation level leading to its relocation in the cytoplasm of alphaT3-1 cells. This suggests that GnRH induces a regulatory loop to amplify SET action on signaling of its own receptor. Finally, we demonstrated that SET expression is markedly increased in the pituitary gland at prœstrus in female rats, providing the first demonstration of a variation of SET expression in a physiological context. Given that GnRHR coupling to the cAMP pathway is increased at prœstrus, our results suggest that SET may play an important role in vivo by promoting such coupling at this particular stage of the estrus cycle
Jan, Gaëlle. "Le rôle d'une sérine-thréonine phosphatase de type 2C parasitaire (TgPP2C) dans l'interaction Toxoplasma gondii - cellule hôte : Identification des modules interactifs au sein du tricomplexe actine-toxofiline-TgPP2C et étude de ses propriétés fonctionnelles dans le parasite et la cellule infectée." Phd thesis, AgroParisTech, 2007. http://pastel.archives-ouvertes.fr/pastel-00002663.
Boissel, Laurent. "Étude de la voie de signalisation RalB dans le développement embryonnaire du Xénope : analyse fonctionnelle des domaines protéiques de l'effecteur XRLIP, et identification de ses partenaires." Paris 7, 2002. http://www.theses.fr/2002PA077029.
Benhenda, Shirine. "Identification de nouveaux partenaires de la protéine HBx du virus de l'hépatite B et étude fonctionnelle de leur interaction avec HBx dans la réplication virale." Paris 7, 2010. http://www.theses.fr/2010PA077228.
Despite availability of efficient hepatitis B virus (HBV) vaccines, the number of chronic HBV carriers is still increasing Worldwide and presently, most treatments remain poorly efficient. HBx is a promising therapeutic target because it is involved in viral replication and oncogenesis. Interaction between HBx and DDB1 is essential for HBx activities. DDB1 has been identified as a subunit of the E3 ligase Cul4/DDBl. Many viral proteins hijack E3 ligases in order to modify the stability of keys cellular proteins, favouring the viral replicative cycle. We have thus postulated that HBx could also hijack E3 ligase. We first utilized tandem affinity purification to isolate new HBx partners. We identified nearly thirty new interacting HBx partners, including components of the Cul4A E3 ligase confirming our hypothesis. We also identified PRMT-1, Spindlin-1 and UbcHlO as new interacting partners. PRMT-1 is a methyltransferase involved in transcriptional regulation. Our data have encovered new epigenetic mechanisms that implicate PRMT1 in the activity of the cccDNA. We have identified Spindlin-1 as a substrate recruited by HBx on the E3 ligase Cul4/DDBl. Our results indicate that HBx might increase Spindlin-1 modification By a K63-linked ubiquitin chain, suggesting a non proteolytic function. Finally, studies of the interaction between HBx and UbcHlO led us to identify APC/C/Cdc20 as the E3 ligase potentially involved in HBx dégradation. Our results using a lysine-less HBx mutant suggest that HBx could be ubiquitylated at the N-terminus. Better understanding of the mechanisms underneath will help developing new therapeutical approaches for treatment of chronic HBV carriers
Delevoye, Cédric. "Identification de protéines sécrétées par Chlamydia et étude fonctionnelle d'une protéine insérée dans la membrane de la vacuole, à l'interface entre les bactéries et leur hôte." Paris 11, 2006. http://www.theses.fr/2006PA112017.
Chlamydiae are obligate intracellular pathogens of humans and animals. Depending on the species, they are responsible for ocular and genital infections, and respiratory diseases. After inducing their own entry, the bacteria develop in a membrane-bound compartment, called the inclusion. During the infectious cycle, they translocate a subset of proteins via a type three secretion (TTS) apparatus into the host cytosol. Among these, the Inc proteins remain anchored in the inclusion membrane where they face the host cytosol. My work has focused on bacterial proteins secreted into the host cell. By a global approach, we have identified 24 new proteins secreted by the TTS apparatus of Chlamydia. This work has opened the functional studies of these bacterial proteins that are in contact with the host cell cytosol. More specifically, we have studied the function of an inclusion protein, IncA. We have shown that IncA, from different chlamydial species, share structural and functional homologies with the SNARE family of eukaryotic proteins, which are essential factors for cellular membrane fusion events. We have shown that IncA interact with SNAREs in both a cellular and an in vitro model. Moreover, in liposome fusion assays, IncA inhibit membrane fusion induced by a cognate SNARE complex specific from the late endosomal compartment. We propose that IncA, by mimicking SNAREs proteins, participate in the control of the interactions between the inclusion membrane and intracellular compartments of the host cell
Seissler, Tanja. "Inhibition traductionnelle du facteur de restriction APOBEC3G par la protéine Vif du VIH-1 : rôle d'une uORF dans la 5'-UTR de l'ARNm d'A3G et identification de facteurs cellulaires." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAJ028.
The HIV-1 Vif protein counteracts the restriction factor APOBEC3G (A3G) by downregulating its expression level in infected cells. This is achieved in different ways, one of which is translational inhibition, a mechanism that is still poorly understood. The first part of my thesis contributes to the characterization of a small upstream ORF (uORF), that is found in the 5'-UTR of A3G and A3F mRNAs. This uORF has been found to be crucial for regulation of A3G translation and is necessary to allow Vif-mediated translational inhibition. In the second part of this thesis, different protocols have been set up in order to identify A3G mRNA-associated cellular proteins which might play a role in the mechanism of Vif-mediated translational inhibition. Several proteins, whose presence on A3G mRNA seems to be modulated by Vif have been identified
Côté-Martin, Alexandra. "Identification des partenaires protéiques de l'hélicase virale E1 du virus du papillome humain : caractérisation d'une nouvelle interaction avec la protéine à domaines WD p80." Thèse, 2007. http://hdl.handle.net/1866/15251.
Tarasov, Kirill. "Searching for novel gene functions in yeast : identification of thousands of novel molecular interactions by protein-fragment complementation assay followed by automated gene function prediction and high-throughput lipidomics." Thèse, 2014. http://hdl.handle.net/1866/11824.
Briot, Julie. "Identification biochimique et fonctionnelle des domaines structuraux d’une sous-unité des canaux calciques." Thèse, 2018. http://hdl.handle.net/1866/21202.