Dissertations / Theses on the topic 'Hox proteins'
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Goh, Siew-Lee. "Functional studies of MEIS1, a HOX co-factor." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103200.
Full textSvingen, Terje, and n/a. "Hox Transcription Factors: Their Involvement in Human Cancer Cells and In Vitro Functional Specificity." Griffith University. School of Biomolecular and Biomedical Science, 2005. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050830.135356.
Full textSvingen, Terje. "Hox Transcription Factors: Their Involvement in Human Cancer Cells and In Vitro Functional Specificity." Thesis, Griffith University, 2005. http://hdl.handle.net/10072/365774.
Full textThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Physical Sciences
Full Text
Phelan, Michael Leo. "A molecular analysis of functional differences between hox proteins." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0026/NQ37012.pdf.
Full textChoo, Siew Woh. "The in vivo specificity of HOX proteins in Drosophila." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609425.
Full textIaroshenko, V. (Vladislav). "Role of human HOX-proteins in different cancer types." Bachelor's thesis, University of Oulu, 2019. http://jultika.oulu.fi/Record/nbnfioulu-201905221901.
Full textLitim-Mecheri, Isma. "Spécificité des protéines Hox : Rôle des motifs connus et découverte de nouveaux motifs." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22096.
Full textHox genes are responsible for the identity of segments along the antero-posterior axis. They are evolutionarily conserved and encode transcription factors. In vitro, all Hox proteins bind to a similar nucleotide sequence via a highly conserved DNA binding domain, the homeodomain (HD). This low specificity of DNA binding in vitro contrasts with their specificity in vivo. One way to explain this paradaox is that Hox protein function with protein cofactors, best represented by Extradenticle (Exd) in Drosophila, Pbx in mammals (collectivaly refered as PBC). Hox-PBC interaction relies on a motif located upstream of the HD, conserved in most Hox proteins, the Hexapeptide (HX). Recent work in our group identified a novel mode of Hox-PBC interaction, non-generic, specific to a subset only of Hox paralog groups, and relying on a motif located C-terminal to the HD. This highlight plasticity in Hox-PBC interaction.My PhD work aimed at investigating the mode of action of Hox protein, by studying the function of three protein motifs, with known or putative role in Exd recruitment by the Drosophila Hox protein AbdominalA (AbdA). The approach taken aimed at analyzing, using a large functional window, how these motifs, taken in isolation or collectively, define AbdA protein activity. Conclusions highlight the absence of pleitropy and a high degree of functional interaction for these protein motifs. The second part of my PhD work has been to initiate the search for novel functionally important protein motifs within Hox proteins. This was approached by selecting phylogenetically conserved motifs, and addressing their function in vitro and in vivo following motif mutations. At least one functional domain was isolated, that contributes predominantly to Dfd protein function
Weicksel, Steven E. "hox Gene Regulation and Function During Zebrafish Embryogenesis: A Dissertation." eScholarship@UMMS, 2013. https://escholarship.umassmed.edu/gsbs_diss/692.
Full textWeicksel, Steven E. "hox Gene Regulation and Function During Zebrafish Embryogenesis: A Dissertation." eScholarship@UMMS, 2010. http://escholarship.umassmed.edu/gsbs_diss/692.
Full textRinaldi, Lucrezia. "Novel functions for Hox proteins in the development of the spinal cord." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0261/document.
Full textHox genes encode conserved homeodomain transcription factors that coordinate the specification of regional body identity during the development of bilaterian animals. There are 39 Hox genes in higher vertebrates, organized into four complexes (named A to D) on the chromosomes. Thirteen groups of paralogue genes occupy similar positions within the complexes and exhibit similar modes of expression and functions. In addition to their specific functions, for which these transcription factors are well known, some recent studies are suggestive of "generic" functions, i.e. functions common outside paralogy groups. The goal of this thesis was to look for generic functions of vertebrate Hox proteins, focusing on the development of the spinal cord in chick and mouse. We identified two such functions, implying B cluster Hox genes. The first regards the potential of Hox proteins to control autophagy, which was previously established for Drosophila Hox proteins in the fat body. My work established the spatio temporal dynamic of autophagy during spinal cord development in chick and mouse embryos. This dynamic identified complementary autophagy and Hox patterns, suggesting a generic role for Hox proteins in the repression of autophagy, which could be confirmed by gain of function in chick embryo. The second Hox generic function regards the control of spinal cord neurogenesis. The study of Hox expression highlighted a predominant expression of B cluster Hox genes in the neural tube Intermediate Zone (IZ), where they activate the expression of the Lzts1 gene, the product of which modulates AKT signaling to ultimately control neuronal differentiation
Comelli, Laura. "Localization and dynamics of homeotic oncogenic protein HOXC13 in pre-initiation complex of human DNA replication origins." Doctoral thesis, Scuola Normale Superiore, 2010. http://hdl.handle.net/11384/85938.
Full textMace, Kimberly Ann. "Split ends cooperates with Hox proteins to maintain epithelial integrity in the epidermis during embryonic development /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2003. http://wwwlib.umi.com/cr/ucsd/fullcit?p3099927.
Full textFerretti, Elisabetta. "Molecular studies towards understanding the role of Prep1 (Pbx regulation protein 1) in segmental expression of Hox proteins in the vertebrate hindbrain." Thesis, Open University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396926.
Full textZouaz, Amel. "Etude de la régulation de l'activité transcriptionelle de la protéine Abdominal-A." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4100.
Full textHox genes encode homeodomain-containing transcription factors (HD). Although the HD binds to similar DNA sequences in vitro, Hox proteins display a high functional specificity in vivo. Protein motifs outside of the HD influence Hox specificity through recruiting additional cofactors, with the best characterized being Extradenticle (Exd in Drosophila). Recent evidence from our group has uncovered the functional contribution of AbdA intrinsic motifs to AbdA Exd-dependent functions as well as AbdA Exd-independent functions. My PhD work has aimed to characterize the contribution of AbdA motifs to target gene selection and regulation using a combined approach of ChIPseq/RNAseq in an Exd-independent context. The DNA code identified provides us with new insights about additional transcriptional inputs from additional DNA-binding proteins lying in the vicinity of AbdA recognition sites. Mass spectrometry analysis establishes the occurrence of these additional DNA binding proteins in a multi-protein complex with AbdA. Deciphering the involvement of post-translational modifications in the regulation of Hox protein activity was another aspect of my PhD work. In silico predictive analysis, followed by biochemical approaches and in vivo assays reveal the potential for SUMOylation of AbdA as a potentially important regulatory component of AbdA activity. These preliminary results set the bases for further work aimed at identifying SUMOylated residues on AbdA and the functional relevance of such post-translational modification on AbdA activity regulation
Li-Kroeger, David. "Integration of regional and neural transcription factors controls EGF signaling from sensory organ precursor cells during Drosophila development." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1337351052.
Full textVanderperre, Solène. "Analyse d'interactions Hox/Cofacteur à l'échelle super-résolutive et contrôle transcriptionnel de l'autophagie chez la drosophile." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEN048.
Full textTranscriptional regulation is essential for all cellular functions and is the subject of a number of studies. Technological advances in the field of microscopy open new opportunities to visualize different steps of this mechanism. In particular, it allows visualizing individual TFs at the super resolution scale in vivo.However, an isolated TF is not sufficient to tightly regulate the activation or repression of a target gene. Indeed, different complexes need to cooperate to achieve this level of accurate control. The observation of binary protein-protein interactions bound on a specific DNA sequence would be an asset to decipher the complex mechanism of transcription.The first part of my thesis project consisted to establish the tools allowing the visualization of different Hox-cofactor complexes on a specific target sequence, at confocal resolution and super-resolution. These tools were applied to quantify a specific enrichment of Hox/Exd complexes on a well characterized enhancer called fkh250. This enhancer is regulating the expression of a Drosophila salivary gland gene named forkhead (fkh). I combined Bimolecular Fluorescent Complementation (BiFC) (confocal resolution) or BiFC-PALM (super-resolution) with the ParB/INT system to simultaneously detect Hox/Exd complexes bound to the fkh250 enhancer,respectively.My results confirm a specific enrichment of Hox/Exd complexes on several fkh250 enhancers. Moreover, my preliminary results show the possibility to perform bi-colour PALM for revealing in the same nucleus the Hox/Exd complexes and its target DNA sequences.The second part of my project revealed a new interaction between Hox proteins and a nuclear matrix component, the Lamin C (LamC), in the context of transcriptional repression of autophagy related genes (atg) in Drosophila larval fat body. This work revealed a typical profile of co-expression of Hox and LamC in Drosophila fat body nuclei. This profile was imaged through confocal Lightning microscopy. These results also revealed the importance of genomic loci positionning for the fine control of transcription
Weber, Christine. "Cdx-Hox protein interactions." Thesis, University of Ottawa (Canada), 2008. http://hdl.handle.net/10393/27656.
Full textRonshaugen, Matthew Rand. "Evolution of Hox protein function /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2002. http://wwwlib.umi.com/cr/ucsd/fullcit?p3071026.
Full textClitheroe, Crystal-Leigh. "In-silico analysis of Plasmodium falciparum Hop protein and its interactions with Hsp70 and Hsp90." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1003819.
Full textVeraksa, Alexey Nikolaevich. "Modulators of Hox protein function in Drosophila /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9975051.
Full textGava, Lisandra Marques 1982. "Caracterização e interação do domínio C-terminal da chaperona Hsp90 humana e das co-chaperonas Tom 70 e Hop." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314027.
Full textTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: A função biológica das proteínas está relacionada à sua estrutura tridimensional adquirida pelo processo de enovelamento protéico. Neste contexto, proteínas denominadas, genericamente, de chaperonas moleculares exercem papel fundamental atuando no auxílio do enovelamento correto, no reenovelamento e na dissociação de agregados protéicos. A Hsp90 é uma das chaperonas moleculares mais importantes, é essencial para a viabilidade celular em eucariotos e está normalmente associada a proteínas atuantes no ciclo e sinalização celular, o que torna essa chaperona um alvo bastante interessante para abordagens terapêuticas de diversas doenças. A Hsp90 pode ser modulada por co-chaperonas diversas. Nesse trabalho foram caracterizadas as proteínas CHsp90 (domínio C-terminal da Hsp90 humana), e as co-chaperonas Hop e Tom70, além da interação entre C-Hsp90 e Tom70. Foram aplicadas técnicas de dicroísmo circular e emissão de fluorescência do triptofano; seguidas pela caracterização por ultracentrifugação analítica, gel filtração analítica, espalhamento dinâmico de luz, cromatografia de gel filtração acoplada a espalhamento de luz em multi-ângulos (SEC-MALS) e gel nativo. Para os ensaios de interação foram aplicadas técnicas de pull-down, SEC-MALS e calorimetria de titulação isotérmica. As proteínas foram produzidas puras e enoveladas, com estado oligomérico determinado como dímero para C-Hsp90 e monômero para Hop e Tom70, sendo que essas também foram encontradas como espécies diméricas. A estequiometria de interação entre a C-Hsp90 e Tom70 foi determinada em 1 monômero da Tom70 para 1 dímero da C-Hsp90, com KD de 360 ± 30 nM, ?Happ = -2,6 ± 0,1 kcal/mol e ?S = 21 ± 1 cal/mol.K, sugerindo que a interação é dirigida por entalpia e entropia. Os resultados obtidos nesse trabalho contribuem para uma melhor compreensão do sistema Hsp90, que está envolvido em diversos processos celulares essenciais e patológicos, como doenças neurodegenerativas, processos inflamatórios, infecções e câncer
Abstract: The biological function of proteins is related to its three dimensional structure acquired via protein folding process. In this context, the molecular chaperones play a key role acting as auxiliary protein on protein folding, refolding and dissociation of protein aggregates. Hsp90 is one of the most important molecular chaperones, is essential for cell viability in eukaryotes and is usually associated with proteins involved in cell cycling and cell signaling, which makes these chaperone a very interesting targeting for therapeutic approaches for several diseases. The chaperone activity of Hsp90 can be modulated by other proteins, called co-chaperones. In this work, we characterized the protein C-Hsp90 (Cterminal domain of human Hsp90) and the co-chaperones Hop and Tom70, and also the interaction between C-Hsp90 and Tom70. Circular dichroism and fluorescence emission of tryptophan was first applied for initial characterization of the proteins, followed by analytical ultracentrifugation, analytical gel filtration, dynamic light scattering, size exclusion chromatography - multi angle light scattering (SEC-MALS) and native gel. The interaction between C-Hsp90 and Tom70 were measured by techniques like pull-down, SEC-MALS and isothermal titration calorimetry. The proteins were produced pure and soluble and their oligomeric state were determined as dimer for C-Hsp90, and monomer for Hop and Tom70, these two co-chaperones were also found as dimeric species. The stoichiometry of interaction between C-Hsp90 and Tom70 was determined by SEC-MALS and ITC as been 1 dimer of C-Hsp90 to 1 monomer of Tom70, with a KD of 360 ± 30 nM, ?Happ = -2.6 ± 0.1 kcal/mol and ?S = 21 ± 1 cal/mol.K, suggesting that these interaction is driven by both, enthalpy and entropy. The results contribute to a better understanding of the important Hsp90 machinery, which is involved in many essential cellular and pathological processes, such as neurodegenerative diseases, inflammation, infection and cancer
Doutorado
Bioquimica
Doutor em Biologia Funcional e Molecular
Rui, Edmilson. "Mutagenese da proteina HBx do virus da hepatite B e estudo da interação com RNA e proteinas humanas." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314356.
Full textTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: A hepatite B constitui um grave problema de saúde pública. Dados epidemiológicos estimam que aproximadamente 350 milhões de pessoas são portadores do vírus da hepatite B (HBV). Admite-se que a infecção evolui para a cura em média 95% dos casos, entretanto nos portadores crônicos a infecção pode evoluir para cirrose e carcinoma hepatocelular (HCC). Há um crescente acúmulo de evidências que relaciona a proteína HBx do HBV ao desenvolvimento do HCC. A maioria dos estudos sobre a função da proteína HBx sugere que ela é uma proteína reguladora de funções pleiotrópicas com a capacidade de induzir o crescimento tumoral. Isso é possivelmente devido à sua capacidade de interagir com uma vasta gama de proteínas celulares. No presente estudo investigamos os aspectos moleculares da estrutura e função da proteína HBx e os resultados foram contextualizados no processo de transformação celular. Observamos pela primeira vez a capacidade da proteína HBx em se ligar ao RNA contendo seqüências ricas em adenina e uracila (AU), que são presentes em alguns proto-oncogenes como c-myc e c-fos. A geração de proteínas truncadas permitiu mapear a região de interação entre HBx e RNA. Realizamos ensaios de mutação sítio-dirigida em HBx e substituímos todas as cisteínas por serinas. Nossos resultados sugerem que as cisteínas na proteína HBx são de menor importância para a sua interação com o RNA e com as proteínas humanas p53 e RXR. Descobrimos ainda uma nova proteína humana que interage com HBx: E4F. Este fator de transcrição humano está relacionado com o controle do ciclo celular, com a segregação cromossômica e com a embriogênese. Ensaios em leveduras e in vitro mostraram que HBx selvagem, bem como as suas formas mutadas, foram capazes de interagir e regular a função de E4F, indicando um possível novo mecanismo para a transformação celular e a regulação da transcrição viral, uma vez que E4F exibiu uma capacidade de interagir com a região ¿enhancer II¿ do genoma do HBV
Abstract: Viral hepatitis is an important global public health problem. Epidemiological data show that worldwide 350 million people are chronically infected with the hepatitis B virus. About 95% of the infections cure spontaneously, but the chronically infected patients may develop liver cirrhosis or even hepatocellular carcinoma (HCC). A large body of evidence points to the viral onco-protein HBx as the principal cause for the cellular transformation. The majority of studies on HBx function suggest that it is a regulatory protein with pleiotropic functions and its capacity to induce tumor growth may be due to its ability to interact with a diverse array of cellular proteins. In the present study we investigated molecular and structural aspects of the function of the HBx protein in order to be able to shed light on the process of cellular transformation. We were able to demonstrate that HBx protein has the ability to bind to an AU-rich RNA sequences present in the mRNAs of certain proto-oncogenes such as c-myc and c-fos. The generation of truncated proteins allowed to map the region of interaction of HBx with the RNA. Furthermore, we performed site directed mutagenesis studies of HBx protein and substituted all of its cysteine residues with serines. Our data suggest that the cysteine residues in the HBx protein are of minor importance for its interaction with RNA, p53 and RXR proteins. Finally, we discovered in E4F a new human interacting protein partner for the HBx protein. The transcription factor E4F has been functionally implicated in the control of the cell cycle, the chromosomal segregation and embriogenesis. In studies using the yeast we further showed that wild-type HBx, as well as its mutated forms, can physically interact with the E4F protein and regulate its function. This indicates a possible new mechanism of cellular transformation and the regulation of the viral transcription, since the human protein E4F demonstrated the capacity to bind to the enhancer II region of the HBV genome
Doutorado
Bioquimica
Doutor em Biologia Funcional e Molecular
Angell, Yu Li. "Triazole based peptidomimetics for mimicking protein-protein hot spots." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1432.
Full textFoos, Nicolas. "Etudes structurales d'un complexe HOX-PBC de drosophile. : Un exemple de régulateur transcriptionnel." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4075.
Full textHox proteins are homeodomain proteins belonging to the Transcription Factors superfamilly. These proteins are necessary for the determination of the cellular identity along the anteroposterior, dorsoventral and proximodistal axes. It's essential to recognize DNA targets with high specificity. One possible mechanism to acquire specificity implies the cooperativity between Hox and their PBC partners. Ubx (Hox) and Exd (PBC) proteins from D. melanogaster are the object of this work. One mechanisme of coopertivity involves the “hexapeptide” motif in Ubx and another one that involves its UbdA motif. The UbdA motif is located C-terminal to the recognition helix. We have solved seven different structures of Ubx-Exd-DNA complexes. Thanks to these structures, we show that UbdA can have a multipurpose role : it can provide an interaction surface to contact Exd and it can also act like a hinge between the C-terminal regions of Ubx and its homeodomain. UbdA and HX motifs from Ubx are not the only regions involved in the control of these proteins functions. Ubx and Exd also contain intrinsically disordered regions which are the linker region and the homeodomain N-terminal arm, for Ubx and Exd respectively. They interact with the DNA in the minor groove and can explore the space around. We studied the Exd 's C-terminal motif and determined that it has a flexible, helical fold. The folding of this fourth helix could modify the contacts established with Ubx and with the DNA. All these observations allow us to add supplementary information for the understanding of functional specificity and provide new arguments for the monkey-bar and for the « gliding interface » DNA- scanning models
Scheufler, Clemens. "Struktur-Funktions-Analyse von Hop Tpr-vermittelte Protein-Protein-Wechselwirkungen /." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=962034444.
Full textReyes, Samuel Onofre J. "Expanding beta-turn analogs for mimicking protein-protein hot spots." Thesis, [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1748.
Full textReis, Dayane Eliara Bertolino. "Caracterização estrutural da Hsp70/Hsp90 organizing protein (Hop) de Plasmodium falciparum." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/75/75133/tde-28022018-095723/.
Full textMalaria is a neglected tropical disease caused by protozoa of the genus Plasmodium spp, affects populations in more than 100 countries around the globe, presenting 219 million new cases per year and is therefore a serious public health problem. It presents a complex and digenetic cycle, necessitating the vector mosquito and the vertebrate host to complete - this cycle involves transformation and adaptation stages, since the pathogen goes through 28 different forms along the cycle, besides facing situations of thermal stress , At the time of the contagion and during the feverish peaks. Thus, it is necessary that the protozoan guarantees its survival and makes possible a host infection. This is accomplished with the assistance of molecular chaperones, proteins that are overexpressed in the intra-erythrocyte stage. A life of proteins and Hsp90, a protection of thermal shock with different functions, among them, maturation of client proteins, routing of proteins for membrane translocation and labeling of proteins for degradation. To comply properly, for example, as Hsp90 rely on the help of co-chaperones, such as Hsp70 / Hsp90 Organizing Protein (Hop) that modulate their function. The Hop is a co-chaperone system folded by Hsp70 and Hsp90 cytoplasmic and which acts as an adapter protein transferring client proteins from the first to the second molecular chaperone. The interaction of Hop with Hsp70 and Hsp90 occurs via TPR domains, which bind to the EEVD motif present at the C-terminus of both as cytoplasmic chaperones. It is found in several organisms, including Plasmodium falciparum, the etiologic agent of malaria. Therefore, knowing a Hop of P. falciparum (PfHop), structurally and functionally, is important for the understanding of the functioning of Hsp90 and Hsp70, essential proteins for a pathogen survival and, therefore, in all the therapeutic aspects. A recombinant PfHop was obtained in greater than 95% purity. The biophysical characterization by the same brand made through different techniques. As there is Hops, a PfHop is mostly constituted by alpha helices. The indicated parameters are a PfHop behaves as a monomer-dimer balance when in solution. Higher low-angle X-ray scattering data on PfHop as a dimeric and elongated protein. This work of master\'s dissertation allowed to reach a structural characterization of the PfHop and with this knowledge, it is expected to advance in the functional characterization of the same in Hsp70 and Hsp90.
Yuan, Ming. "Antiphagocytosis by Yersinia pseudotuberculosis : role of the YopH target proteins." Doctoral thesis, Umeå : Umeå University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-957.
Full textZerbe, Brandon S. "Computational characterization of protein hot spots." Thesis, Boston University, 2012. https://hdl.handle.net/2144/31628.
Full textPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
Protein hot spots provide a large portion of the binding free energy during interact ions, and detecting and characterizing these hot spot regions provides insight that can be used in the development of novel drugs for t he purpose of regulating pathological pathways. In t his dissertation, I first compare t he FTMap algorithm, which detects hot spots by identifying locations where different simulated solvent-sized molecules are consistently found to have favorable interactions, to experimental methods that detect hot spots by alternative means. Specifically, I show that FTMap detects the hot spots detected by alanine scanning, and I discover two roles for residues near hot spots in protein-protein interaction (PPI) complexes. Furthermore, additional insights into the binding energetics of PPis are uniquely provided by FTMap, and these insights are important for drug-design. FTMap is then shown to detect the hot spots identified by successful fragment-screening experiments, and the additional sites detected by FTMap are shown to provide insight into the optimal regions for ligand extension for the molecules identified by t he fragment-screening experiment. Since binding sites are composed of multiple hot spots, we have recently used FTMap for binding site detection. I examine the highly accurate binding site detection algorithm, show that the success of this algorithm is a consequence of only a portion of the scoring protocol, and develop a faster protocol for binding site detection based on this insight. I also quantitate the improvement in precision obtained by using multiple probes and argue t hat the principle biophysical considerations in hot spot detection are hydrophobicity and complexity. Finally, I develop a functional-group clustering algorithm, which is informative for evaluation of the binding locations of pre-determined chemical moieties. I then provide evidence that other approaches employing FTMap results may lead to insight into selectivity. I conclude with a discussion on the nature of hot spots, and I suggest that evolutionary studies of protein divergence should provide insight into the emergence of chemical-selectivity thus providing biophysical insight into the factors that drive selectivity within hot spots.
2031-01-01
Giraud, Guillaume. "Dose et cofacteurs des protéines Hox lors du développement des organes de vol chez les insectes." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEN089.
Full textDuring evolution, animais have developed an astonishing morphological diversity, allowing them to adapt to a wide variety of environments. One of the most striking examples is the radiation of flight appendages in insects, starting from ancestors with two similar pairs of wings. Severa! studies showed the implication of a particular Hox gene, Ultrabithorax ( Ubx), in the formation of posterior flight organs. These organs correspond to the "halteres" in Diptera. Conversely, the formation of anterior flight organs is considered to be Hox independent.During my Ph.D work, we have questioned this mode!. We showed that the Hox protein Antennapedia (Antp) is produced in the wing primordium of the fruit fly Drosophi/a melanogaster and is required for the formation of forewings. Surprisingly, the express ion level of Antp is much lower than the level of Ubx in the haltere primordium, and the artificial increase of Antp level can transform the wing into a haltere. Conversely, the artificial decrease of the Ubx level can induce a haltere to wing transformation. These results show that this is not the type of the Hox protein, here Antp or Ubx, but the specific dose, which is important for the formation of a wing or a haltere in Drosophi/a. We also identified the transcription factor Homothorax (Hth) as an upstream regulator of Antp and Ubx in the wing and haltere primordia respectively. The observation of a correlation between Hox dose variation and wing morphology in other insect lineages supports a new mode! in which morphological diversification of flight organs during insect evolution could arise from changes in the Antp and Ubx expression level. How the Ubx protein could specify the haltere developmenta l program at the molecular level remains elusive. lt is expected that the dose-specific activity of Ubx in the haltere could rely on the interaction with other transcr iptiona l partners. 1 present two complementary approaches that 1 developed ta capture such cofactors. While one approach is still ongoing, the other led ta the identification of interesting putative Ubx-partners. This work also revea led a surpr ising robustness in the Ubx transcr iptional program that may expia in why halteres diverged very little during insect evolution
Hudry, Bruno. "Application de la complémentation de fluorescence bi-moléculaire à l'étude du mode d'action des protéines Hox in vivo." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22087/document.
Full textMy current laboratory aims to tackle the issue of specificity and diversity of regulatory molecules, taking the Drosophila Hox transcription factors as a paradigm for the analysis. During my PhD, I developed three connected research lines.Project 1: Visualization of protein interactions in living Drosophila embryos by the BiFC assayOur results establish the general suitability of BiFC for revealing and studying protein interactions in their physiological context during the rapid course of Drosophila embryonic development.Project 2: Investigation of Hox/PBC complex formation in vivo using BiFC Our findings challenge the current paradigm of Hox/Pbx complex assembly: (a) highlighting the existence of alternative modes of Pbx recruitment, (b) demonstrating that unique Hox-PBC interaction modes can provide specific regulatory function in absence of DNA-binding selectivity.To achieve this project BiFC was also performed with vertebrate Hox proteins in chicken embryos.Project 3: Realization of a candidate interaction screen based on BiFC to identify novel Hox protein partners in vivo(a) We have revealed that Hox proteins establish specific interactions with different subunits of the general mediator complex. These results constituted one of the rare studies making a direct link between the Hox regulators and components of the basal transcriptional machinery, in a physiological context.(b) We have discovered that Hox proteins can interact with importin proteins. This result allows us to assess the importance of controlling the nuclear localization of Hox proteins for controlling their regulatory activities during embryogenesis
Melén, Karin. "Topology Prediction of Membrane Proteins: Why, How and When?" Doctoral thesis, Stockholm University, Department of Biochemistry and Biophysics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6875.
Full textMembrane proteins are of broad interest since they constitute a large fraction of the proteome in all organisms, up to 20-30%. They play a crucial role in many cellular processes mediating information flow and molecular transport across otherwise nearly impermeable membranes. Traditional three-dimensional structural analyses of membrane proteins are difficult to perform, which makes studies of other structural aspects important. The topology of an α-helical membrane protein is a two-dimensional description of how the protein is embedded in the membrane and gives valuable information on both structure and function.
This thesis is focused on predicting the topology of α-helical membrane proteins and on assessing and improving the prediction accuracy. Reliability scores have been derived for a number of prediction methods, and have been integrated into the widely used TMHMM predictor. The reliability score makes it possible to estimate the trustworthiness of a prediction.
Mapping the full topology of a membrane protein experimentally is time-consuming and cannot be done on a genome-wide scale. However, determination of the location of one part of a membrane protein relative to the membrane is feasible. We have analyzed the impact of incorporating such experimental information a priori into TMHMM predictions and show that the accuracy increases significantly. We further show that the C-terminal location of a membrane protein (inside or outside) is the optimal information to use as a constraint in the predictions.
By combining experimental techniques for determining the C-terminal location of membrane proteins with topology predictions, we have produced reliable topology models for the majority of all membrane proteins in the model organisms E. coli and S. cerevisiae. The results were further expanded to ~15,000 homologous proteins in 38 fully sequenced eukaryotic genomes. This large set of reliable topology models should be useful, in particular as the structural data for eukaryotic membrane proteins is very limited.
Melén, Karin. "Topology prediction of membrane proteins : why, how and when? /." Stockholm : Department of biochemistry and biophysics, Stockholm university, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6875.
Full textMorén, Björn. "Caveolae associated proteins and how they effect caveolae dynamics." Doctoral thesis, Umeå universitet, Institutionen för medicinsk kemi och biofysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-92500.
Full textPérez, Culubret Adrià 1993. "Learning how to simulate : Applying machine learning methods to improve molecular dynamics simulations." Doctoral thesis, TDX (Tesis Doctorals en Xarxa), 2022. http://hdl.handle.net/10803/673392.
Full textChauvet, Sophie. "Fonctions des proteines hox : determinants intrinseques de specificite et genes effecteurs chez drosophila melanogaster." Aix-Marseille 2, 1999. http://www.theses.fr/1999AIX22052.
Full textDaniel, Sheril. "Molecular characterization of the Hsp70/Hsp90 organizing protein (Hop) phosphorylation, subcellular localization and interaction with Hsp90." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1004056.
Full textCambronero, Christoffer. "Multiplex protein data and how to handle it." Thesis, Uppsala universitet, Statistiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-297390.
Full textZhang, Jingji. "Accuracy of mRNA Translation in Bacterial Protein Synthesis." Doctoral thesis, Uppsala universitet, Struktur- och molekylärbiologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-262901.
Full textPage, Suzannah Jayne. "The expression of Hex, fli1 and Tal1 proteins in Xenopus embryos." Thesis, University of Portsmouth, 2011. https://researchportal.port.ac.uk/portal/en/theses/the-expression-of-hex-fli1-and-tal1-proteins-in-xenopus-embryos(0b7d6bcd-076c-4d5f-a6f7-cc6420cc4846).html.
Full textStutchbury, Benjamin. "Understanding how focal adhesion proteins sense and respond to mechanical signals." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/understanding-how-focal-adhesion-proteins-sense-and-respond-to-mechanical-signals(f46e2121-1642-41b8-98f6-e0c168d6f01e).html.
Full textGuimarães, Larissa Oliveira. "Caracterização de subpopulações de Leucemia Mielóide Aguda portadora do rearranjo MLL quanto à resposta diferencial ao tratamento em longo prazo com Citarabina." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/17/17135/tde-07012016-115206/.
Full textThe heterogeneity of Acute Myeloid Leukemia (AML) became a challenge for the success of the conventional chemotherapy agent Cytarabine (Ara-C), especially in leukemias with poor prognosis, as those harboring MLL rearrangement. Since AML-MLL cells are considered sensitive to Ara-C when compared with leukemias that do not carry the rearrangement, but relapse is frequent, the present dissertation proposed to study the relationship between biological characteristics related to the basis of chemoresistance to Ara-C in AML-MLL. We proposed an approach based on the selection of subpopulations of cell lines bearing MLL rearrangement submitted to the long-term treatment with Ara-C, comparing them with the cell lines that were not previously exposed to the drug. The cells were characterized according to: 1) the proliferative potential in the presence and absence of Ara-C; 2) the distribution of the cells in the cell cycle; 3) distribution of hematopoietic stem cell classic surface markers, CD34 and CD38; and, 4) global expression profile of transcribed RNAs. The long-term treatment selected cells that are more resistant to Ara-C than the cells that were not previously treated (parental cells). Besides, according to cell cycle, the cells selected by Ara-C treatment present decreased apoptosis (sub-G1 phase), accumulation in the synthesis phase (S-phase) and increase in the proliferative capability after re-exposition to the drug (G2-M phase). Regarding the hematopoietic stem cell markers, we observed that after Ara-C long-term treatment, one of the cell lines exhibited a bimodal distribution of the CD38 marker. When sorted by flow cytometry, we observed that both subpopulations with distinct levels of CD38 expression, called MV-4-11 CD38High and MV-4-11 CD38Low also showed distinct response to Ara-C. When evaluated regarding to their global gene expression profiles, we verified that MV-4-11 CD38High were more closely related to the parental cells, and MV-4-11 CD38Low made up an isolated group, distinct of the other cell populations. Gene ontology (GO) analysis revealed that among the most representative categories of biological processes, activities associated with proliferative capability, development and response to stimuli were included. The hierarchical clustering analysis showed that: 1) the cluster HOXA of genes of development was more expressed in the MV-4-11 CD38Low than in the MV-4-11 CD38High cells, that presented increased expression of HOXB cluster; 2) the most differentially expressed HOX gene was HOXA13, which according to the literature is associated with poor prognosis in other types of cancer; 3) among the genes associated with response to stimuli, the only one related to Ara-C-metabolizing pathway that was differentially expressed between the cell lines was NME1; 4) those genes that take part in the mismatch repair, base excision repair and nucleotide excision repair pathways were more expressed in the MV-4-11 CD38High than in the MV-4-11 CD38Low cells. Additionally, several cyclin-dependent kinases (CDKs) were also differentially expressed between MV-4-11 CD38High and MV-4-11 CD38Low. Finally, we suggest that the in vitro model proposed in this study to mimic the situation of chemoresistance to Ara-C in subpopulations of AML-MLL, showed that the mechanisms of Ara-C response in this disease, go beyond changes in drug detoxification and metabolization, and seem more associated to proliferative and development advantages of the leukemic cells. These pathways should be explored as potential targets to Ara-C combination therapies.
Sun, An-Qiang. "How Do Enzymes Wear Out? Effects of Posttranslational Modifications on Structure and Stability of Proteins; The Triosephosphate Isomerase Model." Thesis, University of North Texas, 1991. https://digital.library.unt.edu/ark:/67531/metadc798116/.
Full textLin, Zhen St George Clinical School UNSW. "Molecular mechanism of cancer related to urokinase receptor: DNAzyme-mediated inhibition and Novel protein interactors of urokinase receptor." Awarded by:University of New South Wales. St George Clinical School, 2007. http://handle.unsw.edu.au/1959.4/31893.
Full textLacerda, Tonielli Cristina Sousa de. "Papel do complexo PrPc-HOP e vesículas extracelulares em câncer colorretal." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-20092016-101001/.
Full textColorectal cancer (CRC) is the third most common type of cancer in the world. Despite improvements in conventional treatments, approximately two-thirds of CRC patients undergo potentially curative surgery. However, most of these patients evolve poorly, showing recurrence and/or metastasis. Search of new molecular targets for CRC therapy revealed the cellular protein Prion (PrPC) as a putative candidate. Recent studies have shown that PrPC exhibit direct or indirect participation in tumor growth, formation of metastasis, composition of multiprotein complexes and induction of signaling pathways involved in many biological processes such as proliferation. Moreover, PrPC has been described as an important modulator of colorectal tumor growth. Previous findings showed that the interaction between PrPC and its ligand HSP70/90 heat shock organizing protein (HOP) induces gliobastoma proliferation. It is well known that HOP localizes mainly in the cytoplasm but HOP is also secreted associated with extracellular vesicles. In this way, the present study sought to evaluate the role of PrPC-HOP complex and extracellular vesicles in the development and progression of CRC. We demonstrate that HOP induces the migration and invasion of CRC cell lines in a PrPC-dependent manner because the use of HOP peptide, which is able to bind to PrPC, blocking PrPC-HOP complex formation, inhibited the migration and invasion processes. In addition, our data showed that the enhancement of migration and invasion induced by PrPC-HOP interaction is mediated by ERK1/2 pathway activation. These in vitro results lead us to evaluate the PrPC and HOP expression by immunohistochemistry in tissues from patients with different tumor types. Our data showed that these proteins could be important for the initial steps of tumor development, represented by the transition from adenoma to adenocarcinoma. No correlation was found among HOP and/or PrPC expression and metastasis, lymph node involvement, staging, survival or tumor area versus normal tissue. Regarding the role of extracellular vesicles in the progression of colorectal tumors, our results showed that cell lines exhibiting similar aggressive tumor behavior can have a different protein secretion pattern and a distinct profile of extracellular vesicles release, which could induce biological process with different intensities. The conditioned medium and the extracellular vesicles derived from WiDr cell line showed a higher potential to induce migration than HCT8 cell line. Moreover, the negative modulation of VPS4, one of the proteins responsible for multivesicular body formation, showed to be an interesting approach in the study of extracellular vesicles secretion secreted by CRC cells; the negative dominant of VPS4 promoted in the WiDr cell line a reduction in the protein cargo and secretion of the extracellular vesicles, a decrease of cell proliferation and induction of migration process. Therefore, taken together, our data highlights that PrPC-HOP complex can be considered a new therapeutic target in migration and invasion processes of CRC. Moreover, these proteins appeared to be important at onset of tumor formation. The modulation of extracellular vesicles secretion may contribute for delaying the progression of colorectal tumors.
Hawkins, Kenneth R. "Designing the diffusion immunoassay (DIA) : how properties of the analyte affect DIA performance /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8076.
Full textNAPOLI, ILARIA. "How the fragile X mental retardation protein represses protein synthesis: a mechanism of translational control in dendrites." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/765.
Full textRegulated protein synthesis in neuronal dendrites is crucial for synaptic plasticity and brain development. The Fragile X mental retardation protein (FMRP) represses translation of specific mRNAs in neuronal dendrites; how it exerts this effect, however, is largely unknown. One protein that interacts with FMRP is CYFIP1/Sra1, a component of the WAVE complex involved in actin polymerization. Here, we show that CYFIP1/Sra1 also interacts with the cap-binding translation initiation factor eIF4E through a novel domain that is structurally related to that present in eIF4E-BPs; this doman in CYFIP1/Sra1 is necessary for translational repression. Furthermore, the Brain Cytoplasmic RNA 1 (BC1), increases the affinity of FMRP for the CYFIP1-eIF4E complex. Importantly, in the brain CYFIP1 is associated with BC1 RNA as well as with Map1b, an FMRP-target mRNA. Reduction of CYFIP1 in neurons leads to an increase of Map1B protein. BDNF, a developmental stimulus that triggers dendritic protein synthesis, causes CYFIP1/Sra1, FMRP and eIF4E to dissociate in dendrites and at synapses. CYFIP1/Sra1 thus mediates the translational repression of FMRP in the brain. In addition, CYFIP1/Sra1 links translational control with the actin skeleton and therefore potentially with mRNP transport from dendrites into spines. Finally, we dissect one of the molecular mechanisms through which FMRP regulates neuronal mRNA translation and unravel one of the pathways that maybe impaired in patients with the Fragile X Syndrome.
Meyer, Tim [Verfasser]. "How Structural Details Influence the Result of pKa Calculations in Proteins / Tim Meyer." Berlin : Freie Universität Berlin, 2015. http://d-nb.info/1072622351/34.
Full textChun-Yue, Lee. "Exploring the biological functions of AlkB proteins and how they relate to AAG." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/46598.
Full textIncludes bibliographical references.
Our DNA is constantly under the assault of DNA damaging agents that are ubiquitous in nature and unavoidable. Fortunately, our cells have evolved DNA repair mechanisms to maintain genomic integrity against this constant attack. An important type of DNA damage is alkylation damage, which has been the focus of this thesis, the major goal of which is to explore the biological role of a set of alkylation repair proteins, the E. coli AlkB and two human AlkB homologs (ABH2 and ABH3), and how they relate to the 3methyladenine DNA glycosylase (AAG). AAG is a base excision repair (BER) protein that has been well-studied and is known to be involved in the repair of a wide variety of substrates. On the other hand, the direct reversal protein AlkB, and its human homologs, have not been so extensively characterized, but it is known that they can repair not only DNA, but also RNA. Although there are eight human AlkB homologs, attention was focused on ABH2 and ABH3 since they are the more well-characterized homologs and recently implicated in DNA repair.In order to investigate the role of the AlkB proteins, particularly in mammalian cells, I expressed ABH2 and ABH3 in established human cell lines and investigated whether their expression would enhance cell survival after alkylation treatment. However, no detectable phenotype was observed in the cell lines upon treatment with the alkylating agent methyl methanesulfonate (MMS). This is possibly due to endogenous ABH levels being sufficient for repair. We therefore turned to characterization of the Abh2 and Abh3 null mice, as compared to wildtype and to another alkylation repair deficient animal, Aag null mice. In addition to the primary substrates 1methyladenine and 3-methylcytosine, AlkB, ABH2, and ABH3 can also repair an important class of damage, the etheno base DNA lesions, which can also be repaired by AAG.
(cont.) Here we have shown in a mouse model that Abh2 and Abh3 overlap with Aag in protecting mice from sensitivity in response to chemically induced chronic inflammation, in which etheno base lesions are readily generated. In addition, we also employed a biochemical approach using a comprehensive library of lesion-containing DNA oligonucleotides to study the redundancy in repair activity between AAG and AlkB. In doing so, we have found new substrates for AAG and in particular, 1-methylguanine, is a new substrate shared between AAG and AlkB. Thus, although these two proteins employ different mechanisms for repair, our studies established further evidence of the interplay between these proteins and the different repair pathways they represent, underscoring the importance of alkylation damage repair for proper cell homeostasis.
by Chun-Yue Lee.
Ph.D.
Meyer, Tim Friedrich [Verfasser]. "How Structural Details Influence the Result of pKa Calculations in Proteins / Tim Meyer." Berlin : Freie Universität Berlin, 2015. http://nbn-resolving.de/urn:nbn:de:kobv:188-fudissthesis000000099528-6.
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