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Taylor, Daniel. "Classification of protein domain movements using dynamic contact graphs." Thesis, University of East Anglia, 2014. https://ueaeprints.uea.ac.uk/53442/.
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Protein domain movements are of critical importance for understanding macromolecular function, but little is understood about how they are controlled, their energetics, and how to characterize them into meaningful descriptions for the purpose of understanding their relation to function. Here we have developed new methods for this purpose based on changes in residue contacts between domains. The main tool used is the “Dynamic Contact Graph” which in one static graph depicts changes in contacts between residues from the domains. The power of this method is twofold: first the graphs allow one to use the algorithms of graph theory in the analysis of domain movements, and second they provide a visual metaphor for the movements they depict. Using this method it was possible to classify 1822 domain movements from the “Non-Redundant Database of Protein Domain Movements” into sixteen different classes by decomposing the graphs for each individual protein into four elemental graphs which represent the four types of elemental contact change. For each individual domain movement the output of this process provides the numbers of occurrences of each type of elemental contact change. These were used as input for logistic regression to create a predictor of hinge and shear using assignments for these two mechanisms at the "Database of Macromolecular Movements". This predictor was applied to the 1822 domain movements to give a tenfold increase in the number of examples classified as hinge and shear. Using this dataset it was shown that contrary to common interpretation there is no difference between hinge and shear domain movements. The new data is presented online with new websites which give visual depictions of the protein domain movements.
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Qi, Guoying. "A comprehensive and non-redundant database of protein domain movements." Thesis, University of East Anglia, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426345.
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Lin, Jun. "Structures of Poliovirus and Antibody Complexes Reveal Movements of the Capsid Protein VP1 During Cell Entry." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/3047.
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In the infection process, native poliovirus (160S) first converts to a cell-entry intermediate (135S) particle, which causes the externalization of capsid proteins VP4 and the N-terminus of VP1 (residues 1-53). The externalization of these entities is followed by release of the RNA genome, leaving an empty (80S) particle. Three antibodies were utilized to track the location of VP1 residues in different states of poliovirus by cryogenic electron microscopy (cryo-EM). "P1" antibody binds to N-terminal residues 24-40 of VP1. Three-dimensional reconstruction of 135S-P1 showed that P1 binds to a prominent capsid peak known as the "propeller tip". In contrast, our initial 80S-P1 reconstruction showed P1 Fabs also binding to a second site, ~60 Å distant, at the icosahedral twofold axes. Analysis of 80S-P1 reconstructions showed that the overall population of 80S-P1 particles consisted of three kinds of capsids: those with P1 Fabs bound only at the propeller tips; only at the twofold axes; or simultaneously at both positions. Our results indicate that, in 80S particles, a significant fraction of VP1 can deviate from icosahedral symmetry. Similar deviations from icosahedral symmetry may be biologically significant during other viral transitions. "C3" antibody binds to 93-103 residues (BC loop) of VP1. The C3 epitope shifts outwards in radius by 4.5% and twists through 15° in the 160S-to-135S transition, but appears unchanged in the 135S-to-80S transition. In addition, binding of C3 to either 160S or 135S particles causes residues of the BC loop to move an estimated 5 (±2) Å, indicating flexibility. The flexibility of BC loop may play a role in cell-entry interactions. At 37°C, the structure of poliovirus is dynamic, and internal polypeptides VP4 and the N-terminus of VP1 externalize reversibly. An antibody, binding to the residues 39-55 of VP1, was utilized to track the location of the N-terminus of VP1 in 160S particle in the "breathing" state. The resulting reconstruction showed the capsid expands similarly to the irreversibly altered 135S particle, but the N-terminus of VP1 is located near the twofold axes, instead of the propeller tip as in 135S particles.
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Nandadasa, Sumeda A. "Cadherin mediated F-actin assembly and the regulation of morphogenetic movements during Xenopus laevis development." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1276953030.
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Hedberg, Linda. "The birth and growth of the protein folding nucleus : Studies of protein folding focused on critical contacts, topology and ionic interactions." Doctoral thesis, Stockholm University, Department of Biochemistry and Biophysics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-8146.
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Proteins are among the most complex molecules in the cell and they play a major role in life itself. The complexity is not restricted to just structure and function, but also embraces the protein folding reaction. Within the field of protein folding, the focus of this thesis is on the features of the folding transition state in terms of growing contacts, common nucleation motifs and the contribution of charged residues to stability and folding kinetics.
During the resent decade, the importance of a certain residue in structure formation has been deduced from Φ-value analysis. As a complement to Φ-value analysis, I present how scatter in a Hammond plot is related to site-specific information of contact formation, Φ´(βTS), and this new formalism was experimentally tested on the protein L23. The results show that the contacts with highest Φ growth at the barrier top were distributed like a second layer outside the folding nucleus. This contact layer is the critical interactions needed to be formed to overcome the entropic barrier.
Furthermore, the nature of the folding nucleus has been shown to be very similar among proteins with homologous structures and, in the split β-α-β family the proteins favour a two-strand-helix motif. Here I show that the two-strand-helix motif is also present in the ribosomal protein S6 from A. aeolicus even though the nucleation and core composition of this protein differ from other related structure-homologues.
In contrast to nucleation and contact growth, which are events driven by the hydrophobic effect, my most recent work is focused on electrostatic effects. By pH titration and protein engineering the charge content of S6 from T. thermophilus was altered and the results show that the charged groups at the protein surface might not be crucial for protein stability but, indeed, have impact on folding kinetics. Furthermore, by site-specific removal of all acidic groups the entire pH dependence of protein stability was depleted.
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Lombard, Valentin. "Geometric deep manifold learning combined with natural language processing for protein movies." Electronic Thesis or Diss., Sorbonne université, 2024. http://www.theses.fr/2024SORUS379.
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Les protéines jouent un rôle central dans les processus biologiques, et comprendre comment elles se déforment et se déplacent est essentiel pour élucider leurs mécanismes fonctionnels. Malgré les récentes avancées dans les technologies à haut débit, qui ont élargi nos connaissances sur les structures protéiques, la prédiction précise de leurs différents états conformationnels et mouvements reste un défi majeur. Nous présentons deux approches complémentaires pour relever le défi de la compréhension et de la prédiction de l'ensemble de la variabilité conformationnelle des protéines. La première approche, appelée Dimensionality Analysis for protein Conformational Exploration (DANCE), permet une description systématique et complète de la variabilité conformationnelle des familles de protéines. DANCE prend en compte à la fois les structures expérimentales et prédites. Elle est adaptée à l'analyse des protéines individuelles jusqu'aux superfamilles. En l'utilisant, nous avons regroupé toutes les structures protéiques résolues expérimentalement disponibles dans la banque de données Protein Data Bank en collections conformationnelles et les avons caractérisées comme des ensembles de mouvements linéaires. Cette ressource facilite l'accès et l'exploitation des multiples états adoptés par une protéine et ses homologues. Au-delà de l'analyse descriptive, nous avons évalué des techniques classiques de réduction de la dimensionnalité pour échantillonner des états non observés sur un banc d'essai représentatif. Ce travail améliore notre compréhension de la manière dont les protéines se déforment pour accomplir leurs fonctions et ouvre la voie à une évaluation standardisée des méthodes conçues pour échantillonner et générer des conformations protéiques. La deuxième approche repose sur l'apprentissage profond pour prédire des représentations continues du mouvement des protéines directement à partir de séquences, sans avoir besoin de données structurelles. Ce modèle, appelé SeaMoon, utilise des embeddings de modèles de langage protéique (pLM) comme entrées dans un réseau neuronal convolutif léger comptant environ un million de paramètres entraînables. SeaMoon atteint un taux de réussite de 40 % lorsqu'il est évalué sur environ 1 000 collections de conformations expérimentales, capturant des mouvements au-delà de la portée des méthodes traditionnelles comme l'analyse des modes normaux, qui repose uniquement sur la géométrie 3D. De plus, SeaMoon se généralise à des protéines n'ayant aucune similitude de séquence détectable avec son ensemble d'entraînement et peut être facilement réentraîné avec des pLM mis à jour. Ces deux approches offrent un cadre unifié pour faire progresser notre compréhension de la dynamique des protéines. DANCE fournit une exploration détaillée des mouvements protéiques basée sur des données structurelles, tandis que SeaMoon démontre le potentiel des modèles d'apprentissage profond basés sur les séquences pour capturer des mouvements complexes sans dépendre d'informations structurelles explicites. Ensemble, elles ouvrent la voie à une compréhension plus complète de la variabilité conformationnelle des protéines et de son rôle dans la fonction biologiqueProteins play a central role in biological processes, and understanding how they deform and move is essential to elucidating their functional mechanisms. Despite recent advances in high-throughput technologies, which have broadened our knowledge of protein structures, accurate prediction of their various conformational states and motions remains a major challenge. We present two complementary approaches to address the challenge of understanding and predicting the full range of protein conformational variability. The first approach, Dimensionality Analysis for protein Conformational Exploration (DANCE) for a systematic and comprehensive description of protein families conformational variability. DANCE accommodates both experimental and predicted structures. It is suitable for analyzing anything from single proteins to superfamilies. Employing it, we clustered all experimentally resolved protein structures available in the Protein Data Bank into conformational collections and characterized them as sets of linear motions. The resource facilitates access and exploitation of the multiple states adopted by a protein and its homologs. Beyond descriptive analysis, we assessed classical dimensionality reduction techniques for sampling unseen states on a representative benchmark. This work improves our understanding of how proteins deform to perform their functions and opens ways to a standardized evaluation of methods designed to sample and generate protein conformations. The second approach relies on deep learning to predict continuous representations of protein motion directly from sequences, without the need for structural data. This model, SeaMoon, uses protein language model (pLM) embeddings as inputs to a lightweight convolutional neural network with around 1 million trainable parameters. SeaMoon achieves a success rate of 40% when evaluated against around 1,000 collections of experimental conformations, capturing movements beyond the reach of traditional methods such as normal mode analysis, which relies solely on 3D geometry. In addition, SeaMoon generalizes to proteins that have no detectable sequence similarity with its training set and can be easily retrained with updated pLMs. These two approaches offer a unified framework for advancing our understanding of protein dynamics. DANCE provides a detailed exploration of protein movements based on structural data, while SeaMoon demonstrates the potential of sequence-based deep learning models to capture complex movements without relying on explicit structural information. Together, they pave the way for a more comprehensive understanding of protein conformational variability and its role in biological function
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Liu, Huanting. "Molecular biology of maize streak virus movement in maize." Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361478.
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Lai, Yun-Ju. "Role of TRIP6 in LPA-induced cell migration." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2009r/lai.pdf.
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Hu, Xiaohua. "Actin polymerization dynamics at the leading edge." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/39940.
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Actin-based cell motility plays crucial role throughout the lifetime of an organism. While the dendritic nucleation model explains the initiation and organization of the actin network in lamellipodia, two questions need to be answered.
In this study, I reconstructed cellular motility in vitro to investigate how actin filaments are organized to coordinate elongation and attachment to leading edge. Using total internal reflection fluorescence microscopy of actin filaments, we tested how profilin, Arp2/3, and capping protein (CP) function together to propel beads or thin glass nanofibers coated with N-WASP WCA domains. During sustained motility, physiological concentrations of Mg2+ generated actin filament bundles that processively attached to the nanofiber. Reduction of total Mg2+ abolished particle motility and actin attachment to the particle surface without affecting actin polymerization, Arp2/3 nucleation, filament capping, or actin shell formation. Addition of other types of crosslinkers restored both comet tail attachment and particle motility. We propose a model in which polycation-induced filament bundling sustains processive barbed end attachment to the leading edge.
I lowered actin, profilin, Arp2/3, and CP concentrations to address the generation of actin filament orientation during the initiation of motility. In the absence of CP, Arp2/3 nucleates barbed ends that grow away from the nanofiber surface and branches remain stably attached to nanofiber. CP addition causes shedding of short branches and barbed end capture by the nanofiber. Barbed end retention by nanofibers is coupled with capping, indicating that WWCA
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and CP bind simultaneously to barbed ends. In pull-down assays, saturating CP addition only blocks WWCA binding to barbed end by half. Labeled WWCA bound to barbed ends with an affinity of 14 pM and unlabeled WWCA with an affinity of 75 pM. CP addition increased WWCA binding slightly at low CP concentrations and decreased WWCA binding to 50% at high CP concentrations. Molecular models of CP and WH2 domains bound respectively to the terminal and penultimate actin subunit showed no overlap and that CP orientation might blocks WWCA dissociation from the penultimate subunit. Simultaneous binding of CP and WWCA to barbed ends is essential to the establishment of filament orientation at the leading edge.Ph. D.
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Schmidt, von Braun Serena. "Chup1 - a chloroplast movement protein and its interactions." Diss., lmu, 2008. http://nbn-resolving.de/urn:nbn:de:bvb:19-87456.
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Aitken, Angus Iain. "Membrane interactions of plant virus movement proteins." Thesis, University of St Andrews, 2018. http://hdl.handle.net/10023/15617.
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Plant viruses post a significant risk to both global food security, and industrial agriculture, however very little is known regarding their molecular mechanisms. Despite intensive study since the discovery of a multitude of plant virtual movement proteins, it remains unknown how they transverse the plasmodesmata, and thus move between cells. The CMV virus is widespread, infecting over a thousand plant species, and yet the means by which the movement protein CMV 3a associates to cellular membranes, targets itself and viral genomes to plasmodesmata have not been described. This study initially attempted to purify the CMV 3a protein from bacterial expression for structural and biophysical studies to examine viral protein and host membrane interactions. The study also began mapping the CMV 3a protein surface to investigate protein localisation and membrane attachment in planta, identifying structural features, including two potentially amphipathic helices which bear further investigation for potential roles in membrane association. Finally, this thesis examined the potential for the lipid modification S-acylation (Palmitoylation) as a membrane anchor, across a range of viral movement proteins. Describing this modification of viral movement proteins for the first time, S-acylation was demonstrated to not only be widespread, but potentially play different roles across a range of plant virus movement systems. This information is vital for the advancement of the field's understanding of the cell to cell movement of plant viruses, and the potential development of control strategies; and hence the safeguarding of global food security.
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Burman, Alison Jane. "Molecular studies of the cucumber mosaic virus movement protein." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309317.
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Sasaki, Nobumitsu. "Roles of Movement Protein Gene in Cell-to-Cell Movement and Host-Range Determination of Bromoviruses." Kyoto University, 2002. http://hdl.handle.net/2433/149902.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第9612号
農博第1240号
新制||農||841(附属図書館)
学位論文||H14||N3644(農学部図書室)
UT51-2002-G370
京都大学大学院農学研究科応用生物科学専攻
(主査)教授 奥野 哲郎, 教授 西岡 孝明, 教授 泉井 桂
学位規則第4条第1項該当
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Perbal, Marie-Christine. "A functional analysis of the cauliflower mosaic virus movement protein." Thesis, University of East Anglia, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359335.
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Fujita, Yasunari. "ROLE OF BROMOVIRUS 3A MOVEMENT PROTEIN GENE IN HOST SPECIFICITY." Kyoto University, 1998. http://hdl.handle.net/2433/182402.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第7479号
農博第1012号
新制||農||767(附属図書館)
学位論文||H10||N3188(農学部図書室)
UT51-98-N101
京都大学大学院農学研究科農林生物学専攻
(主査)教授 古澤 巌, 教授 泉井 桂, 教授 津田 盛也
学位規則第4条第1項該当
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Zhang, Ziwei. "The structural and functional study of GIT1 paxillin binding domain." View the abstract Download the full-text PDF version, 2008. http://etd.utmem.edu/ABSTRACTS/2008-020-ZiweiZhang-index.html.
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Thesis (Ph.D.)--University of Tennessee Health Science Center, 2008.Title from title page screen (viewed on November 5, 2008). Research advisor: Jie Zheng, Ph.D. Document formatted into pages (xiii, 140 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 105-116).
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Hall, Deborah A. "Prevalence of FMR1 repeat expansions in movement disorders /." Connect to abstract via ProQuest. Full text is not available online, 2008. http://proquest.umi.com/pqdweb?did=1545571851&sid=1&Fmt=6&clientId=18952&RQT=309&VName=PQD.
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Thesis (Ph.D. in Clinical Science) -- University of Colorado Denver, 2008.Typescript. Includes bibliographical references (leaves 59-67). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;
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Poornam, Guru Prasad. "Methods for analysis of domain movements in multimeric proteins and biosupramolecules." Thesis, University of East Anglia, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446460.
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Haley, Ann. "Characterisation of the movement proteins of two plant viruses." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308317.
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Zhou, Xianghua. "New roles of filamins in cell signaling, transcription and organ development /." Göteborg : Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine and the Wallenberg Laboratory, Sahlgrenska Center for Cardiovascular and Metabolic Research at Sahlgrenska Academy, University of Gothenburg, 2009. http://hdl.handle.net/2077/19605.
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Shoji, Shinichiro. "Molecular Analysis of tRNA-mRNA movement in the Ribosome." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243195638.
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Link, Vinzenz. "Identification of proteins controlling gastrulation movements by a proteomic approach in zebrafish." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1145519075954-75369.
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During vertebrate gastrulation, a well-orchestrated series of cell movements leads to the formation of the three germ layers: ectoderm, mesoderm and endoderm. In zebrafish, a model organism for vertebrate development, the mesendodermal progenitor cells separate from the ectodermal cells and migrate towards the animal pole. To identify proteins controlling these processes, I used a comparative proteomic approach following two alternative strategies: (1) Based on the notion that Wnt11 regulates cell movement and morphology during gastrulation independent of transcriptional regulation, I performed a screen aimed at the identification of proteins phosphorylated upon Wnt11 signalling. To regulate Wnt11 expression tightly, I engineered a transgenic slb/wnt11-/- fish line expressing wnt11 under the control of a heat shock promoter. Using this line, I performed a quantitative comparison of protein phosphorylation with or without Wnt11 pathway activation by analysing 32P-labelled embryo extracts on 2D gels. (2) Since these experiments did not reveal any Wnt11 targets, I addressed, in the second approach, proteomic differences causal for the changes in cell adhesion and motility observed in mesendodermal cells upon involution. Quantitative 2D gel analysis comparing ectodermal and mesendodermal cells revealed 37 significantly regulated spots, 36 of which I identified by mass spectrometry. Interestingly, the majority of these proteins were not regulated on a transcriptional level as determined by an accompanying microarray analysis confirming the complementary nature of proteomics and transcriptomics. Among the identified targets, several proteins, including Ezrin2, had previously been assigned a cytoskeleton-related function. I characterised Ezrin2 in more detail showing that Ezrin2 is specifically activated by phosphorylation in mesendodermal cells and that it is required for proper gastrulation movements. In the course of this study, I developed techniques for proteomic analysis of early zebrafish embryos, including a protocol to remove the yolk. I identified several cytoskeleton-related proteins in a comparative proteomic screen for regulators of gastrulation movements. The subsequent characterisation of Ezrin2 confirmed the power of proteomics for the analysis of developmental processes. In conclusion, this work provides a foundation to study developmental and cell biological questions in early zebrafish embryos using proteomics.
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Takeda, Atsushi. "Analysis of Plant Virus Movement Proteins and RNA Silencing Suppressors." Kyoto University, 2004. http://hdl.handle.net/2433/147760.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第10911号
農博第1417号
新制||農||891(附属図書館)
学位論文||H16||N3922(農学部図書室)
UT51-2004-G758
京都大学大学院農学研究科応用生物科学専攻
(主査)教授 奥野 哲郎, 教授 遠藤 隆, 教授 西岡 孝明
学位規則第4条第1項該当
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Eriksson, Therese. "Organelle movement in melanophores: Effects of Panax ginseng, ginsenosides and quercetin." Licentiate thesis, Linköpings universitet, Farmakologi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-19973.
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Panax ginseng is a traditional herb that has been used for over 2000 years to promote health and longevity. Active components of ginseng include ginsenosides, polysaccharides, flavonoids, polyacetylenes, peptides, vitamins, phenols and enzymes, of which the ginsenosides are considered to be the major bioactive constituents. Although widely used, the exact mechanisms of ginseng and its compounds remain unclear. In this thesis we use melanophores from Xenopus laevis to investigate the effects of Panax ginseng extract G115 and its constituents on organelle transport and signalling. Due to coordinated bidirectional movement of their pigmented granules (melanosomes), in response to defined chemical signals, melanophores are capable of fast colour changes and provide a great model for the study of intracellular transport. The movement is regulated by alterations in cyclic adenosine 3’:5’-monophosphate (cAMP) concentration, where a high or low level induce anterograde (dispersion) or retrograde (aggregation) transport respectively, resulting in a dark or light cell. Here we demonstrate that Panax ginseng and its constituents ginsenoside Rc and Rd and flavonoid quercetin induce a concentration-dependent anterograde transport of melanosomes. The effect of ginseng is shown to be independent of cAMP changes and protein kinase A activation. Upon incubation of melanophores with a combination of Rc or Rd and quercetin, a synergistic increase in anterograde movement was seen, indicating cooperation between the ginsenoside and flavonoid parts of ginseng. Protein kinase C (PKC) inhibitor Myristoylated EGF-R Fragment 651-658 decreased the anterograde movement stimulated by ginseng and ginsenoside Rc and Rd. Moreover, ginseng, but not ginsenosides or quercetin, stimulated an activation of 44/42-mitogen activated protein kinase (MAPK), previously shown to be involved in both aggregation and dispersion of melanosomes. PKC-inhibition did not affect the MAPK-activation, suggesting a role for PKC in the ginseng- and ginsenoside-induced dispersion but not as an upstream activator of MAPK.Panax ginseng är ett av de vanligaste naturläkemedlen i världen och används traditionellt för att öka kroppens uthållighet, motståndskraft och styrka. Ginseng är ett komplext ämne bestående av ett antal olika substanser, inklusive ginsenosider, flavonoider, vitaminer och enzymer, av vilka de steroidlika ginsenosiderna anses vara de mest aktiva beståndsdelarna. Flavonoider (som finns i till exempel frukt och grönsaker) och ginseng har genom forskning visat sig motverka bland annat hjärt-och kärlsjukdomar, diabetes, cancer och demens. Trots den omfattande användningen är dock mekanismen för hur ginseng verkar fortfarande oklar. I den här studien har vi använt pigmentinnehållande celler, melanoforer, från afrikansk klogroda för att undersöka effekterna av Panax ginseng på pigment-transport och dess maskineri. Melanoforer har förmågan att snabbt ändra färg genom samordnad förflyttning av pigmentkorn fram och tillbaka i cellen, och utgör en utmärkt modell för studier av intracellulär transport. Förflyttningen regleras av förändringar i halten av cykliskt adenosin-monofosfat (cAMP) i cellen, där en hög eller låg koncentration medför spridning av pigment över hela cellen (dispergering) eller en ansamling i mitten (aggregering), vilket resulterar i mörka respektive ljusa celler. Här visar vi att Panax ginseng, ginsenosiderna Rc och Rd samt flavonoiden quercetin stimulerar en dispergering av pigmentkornen. När melanoforerna inkuberades med en kombination av ginsenosid Rc eller Rd och quercetin, kunde en synergistisk ökning av dispergeringen ses, vilket tyder på en samverkan mellan ginsenosid- och flavonoid-delarna av ginseng. Ett protein som tidigare visats vara viktigt för pigmenttransporten är mitogen-aktiverat protein kinas (MAPK), och här visar vi att också melanoforer stimulerade med ginseng, men dock inte med ginsenosider eller quercetin, innehåller aktiverat MAPK. Genom att blockera enzymet protein kinas C (PKC) (känd aktivator av dispergering), minskade den ginseng- och ginsenosid-inducerade dispergeringen, medan aktiveringen av MAPK inte påverkades alls. Detta pekar på en roll för PKC i pigment-transporten men inte som en aktivator av MAPK.
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Yang, Yen Ching. "The regulation of dynein function in membrane movement by NudEL." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/the-regulation-of-dynein-function-in-membrane-movement-by-nudel(0156ad8a-546f-4ee1-8682-d68d8c782d56).html.
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The accurate regulation of cytoplasmic dynein-1 (dynein) is very important since dynein performs multiple functions in cells. In interphase, dynein is responsible for the correct positioning of membrane organelles, such as the Golgi complex and lysosomes. Previous work suggests that dynein's accessory proteins NudEL/Nde1/LIS1¬ may be involved in regulating dynein-dependent organelle movement. This study focuses on how NudEL regulates dynein-driven membrane movement. By using various NudEL fragments, this work presents the first evidence that NudEL is involved in the regulation of dynein-driven ER movement in vitro. Moreover, the in vivo organelle positioning assays also indicate additional regulatory function of NudEL.NudEL fragment (1-157 aa) which contains both the dynein and LIS1 binding domains is sufficient to activate dynein-driven membrane movement, since NudEL1-157 aa activates ER motility in vitro and enhances clustering of the Golgi complex and lysosomes in the peri-nuclear region in vivo. On the other hand, NudEL 96-206 aa containing the LIS1 binding domain alone inhibits ER motility in vitro and causes scattering of the Golgi complex and lysosomes in vivo, indicating an inhibition of dynein-dependent organelle movement. The activation of dynein activity requires the recruitment of LIS1 to the dynein complex by NudEL, since NudEL 1-157 aa has strong binding affinity to both LIS1 and dynein whereas NudEL 96-206 aa binds to LIS1 but not dynein which suggests the sequestering of LIS1 from the dynein complex. Interestingly, NudEL 1-206 aa, which also contains both the dynein and LIS1 binding domains, causes the dispersal of the Golgi complex and lysosomes in vivo, but to a lesser extent than NudEL 96-206 aa. The putative NudEL regulatory domain (157 -242 aa, which contains various phosphorylation sits and is less conserved between NudEL and Nde1) in NudEL 1-206 aa may regulate the interaction of LIS1 and the dynein complex, since NudEL 1-206 aa has strong binding affinity to LIS1 and weak binding affinity to dynein. However, further work is needed to understand the exact mechanism by which this putative NudEL domain regulates dynein activity.
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Hirst-Dunton, Thomas Alexander. "Using molecular simulations to parameterize discrete models of protein movement in the membrane." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:893568e9-696f-47e7-8495-59ecfb810459.
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The work presented in this thesis centres on the development of a work-flow in which coarse-grained molecular dynamics (MD) simulations of a planar phospholipid bilayer, containing membrane proteins, is used to parameterize a larger-scale simplified bilayer model. Using this work-flow, repeat simulations and simulations of larger systems are possible, better enabling the calculation of bulk statistics for the system. The larger-scale simulations can be run on commercial hardware, once the initial parameterization has been performed. In the simplified representation, each protein was initially only represented by the position of its centre of mass and later with the inclusion of its orientation. The membrane protein used throughout most of this work was the bacterial outer membrane protein NanC, a member of the KdgM family of proteins. To parameterize the motion and interaction of proteins using MD, the potential of mean force (PMF) for the pairwise association of two proteins in a bilayer was calculated for a variety of orientational combinations, using a modified umbrella sampling procedure. The relative orientations chosen represented extreme examples of the contact regimes between the two proteins: they approximately corresponded to maxima and minima of the solvent inaccessible surface area, calculated when the proteins were in contact. These PMFs showed that there was a correlation between the buried surface area and the depth of the potential well in the PMF; this is something that, to date, has only been observed in these relatively-'featureless' membrane proteins (but is seen in globular proteins), where the effect of the interactions with lipids in the bilayer plays a larger role. Features in the PMF were observed that resulted from the preferential organization of lipids in the region between the two proteins. These features were small wells in the PMF, which occurred at protein separations that corresponded to the intervening lipids being optimally packed between the proteins. This result further highlighted the role that the lipids in the bilayer played in the interaction between the NanC proteins. The simplified bilayer model was parameterized using the PMFs and the relationship between buried surface area and potential well depth. The initial model included only the proteins' positions. A series of Monte Carlo simulations were performed in order to compare the system behaviour to that of an equivalent MD simulation. Initially, the MD simulation and our parameterized model did not show a good agreement, so a Monte Carlo scheme that incorporated cluster-based movements was implemented. The agreement between the MD simulation and the simulations of our model using the cluster-based scheme, when comparing diffusive and clustering behaviour, was good. Including the orientation-dependent features of the parameterization resulted in the emergence of behaviour that was not clearly detectable in the MD simulation. Finally, attempts were made to parameterize the model using PMFs for the association of rhodopsin from the literature. Rhodopsin was a much more complicated protein to represent: there was not a clear correlation between surface area and the features of the PMF, and the geometry of the interaction between two rhodopsins was more complicated. Simulations of the 'rows-of-dimers' system of rhodopsin, observed in disc membranes, was not entirely well represented by the model; for such a closely packed system, where the number of lipids is much closer to the number of proteins, the use of an implicit-lipid model meant that the effect of the reduced lipid mobility was not adequately captured. However, the model accurately captures the orientational composition of the system. Future work should be focussed on incorporating explicit representations of the lipid in the system so that the behaviour of close-packed systems are better represented.
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Molk, Jeffrey Nathan Bloom Kerry S. Salmon Edward D. "Microtubule plus end binding proteins and nuclear movements in the Saccharomyces cerevisiae life cycle." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,209.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biology." Discipline: Biology; Department/School: Biology.
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Stear, Jeffrey Hamilton. "Studies of chromosome structure and movement in C. elegans /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/5056.
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Farmer, Hayley. "The influence of dihydropyridines on the transvascular movement of atherogenic plasma proteins." Thesis, Queen Mary, University of London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322085.
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MIYAKE, KOJI, YOSHIKAZU TSUJI, HATSUKI HIBI, and MASANORI YAMAMOTO. "Intraluminal Content is Required for the Maintenance of Antigrade Proluminal Movement of 3H-Androgens into Rat Caput Epididymal Tubules." Nagoya University School of Medicine, 1994. http://hdl.handle.net/2237/15941.
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Ulrich, Florian. "Regulation of Zebrafish Gastrulation Movements by slb/wnt11." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1125651469323-78929.
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During zebrafish gastrulation, highly coordinated cellular rearrangements lead to the formation of the three germ layers, ectoderm, mesoderm and endoderm. Recent studies have identified silberblick (slb/wnt11) as a key molecule that regulates gastrulation movement through a conserved pathway, which shares significant similarity with a signalling pathway that establishes epithelial planar cell polarity (PCP) in Drosophila (Heisenberg et al., 2000; Veeman et al., 2003), suggesting a role for cell polarity in regulating gastrulation movements. However, the cellular and molecular mechanisms by which slb/wnt11 functions during zebrafish gastrulation are still not fully understood. In the first part of the thesis, the three-dimensional movement and morphology of individual cells in living embryos during the course of gastrulation were recorded and analysed using high resolution confocal microscopy. It was shown that in slb/wnt11 mutant embryos, hypoblast cells within the forming germ ring display slower, less directed migratory movements at the onset of gastrulation, which are accompanied by defects in the orientation of cellular processes along the individual movement directions of these cells. The net movement direction of the cells is not changed, suggesting that slb/wnt11-mediated orientation of cellular processes serves to facilitate and stabilize cell movements during gastrulation. By using an in vitro reaggregation assay on mesendodermal cells, combined with an analysis of the endogenous expression levels and distribution of E-cadherin in zebrafish embryos at the onset of gastrulation, E-cadherin mediated adhesion was found to be a downstream mechanism regulating slb/wnt11 function during gastrulation. Interestingly, the effects of slb/wnt11 on cell adhesion appear to be dependent on Rab5-mediated endocytosis, suggesting endocytic turnover of cell-cell contacts as one possible mechanism through which slb/wnt11 mediates its effects on gastrulation movements. - Die Druckexemplare enthalten jeweils eine CD-ROM als Anlagenteil: QuickTimeMovies (ca. 23 MB)- Übersicht über Inhalte siehe Dissertation S. 92 - 93"
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Chubb, Jonathan Robert. "An analysis of the role of the RasS protein in dictyostelium cell movement and endocytosis." Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311944.
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Forrest, Kerrie. "Investigation of the gene family encoding aquaporins, the protein channels regulating water movement, in wheat." Swinburne Research Bank, 2008. http://hdl.handle.net/1959.3/42611.
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Thesis (PhD) - Environment and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology, 2008.Presented for the degree of Doctor of Philosophy, [Environment and Biotechnology Centre, Faculty of Life and Social Sciences], 2008. Typescript. Bibliography: p. 273-312.
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Jeffers, Laura Ann. "The movement of proteins across the digestive system of tobacco budworm, Heliothis virescens." NCSU, 2003. http://www.lib.ncsu.edu/theses/available/etd-11252003-090845/.
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Bovine serum albumin (BSA) and anti-BSA polyclonal antibody were used as model polypeptides to examine protein movement across the insect digestive system and cuticle and their accumulation in hemolymph of fourth stadium tobacco budworms, Heliothis virescens. The use of hydrateable meal pads to deliver a specific concentration of these two proteins in insect diet was investigated. Continuous feeding on artificial diet containing 0.8 mg of anti-BSA/g hydrated diet resulted in 2430±125 and 3459±105 ng of anti-BSA/mL hemolymph after 8 and 16 h, respectively (average ± 1 SEM), as determined by ELISA. Continuous feeding on meal pads with the same concentration of BSA resulted in 1547±132 and 1623±122 ng of BSA/mL hemolymph at 8 and 16 h, respectively. No BSA or anti-BSA was found in the feces, and when 5 mg of these two proteins were applied topically in DMSO to the cuticle, neither protein was found in the hemolymph after 4 h. Western blot analyses using native and/or de-naturing gel electrophoresis demonstrated that both BSA and anti-BSA were not degraded in the hydrated meal pads and were also unchanged in the hemolymph, retaining the multimeric structure for BSA and the antigen reactivity for anti-BSA. When 1 mg of anti-BSA or BSA was injected into the hemocoel of fourth instars, the concentrations decreased with time and 120 min after injection were 0.6 and 20% of the original concentration, respectively. When added at the same original concentration to hemolymph in vitro, the decrease was 81.5 and 57.5%, respectively, at 120 min. Apparently, the accumulation of native anti-BSA and BSA protein in insect hemolymph is the result of the rate of their transfer from the diet versus their rate of turnover in the hemolymph. Hemolymph turnover of these proteins appears to be the result of degradation and sequestration.
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Vogt, Daniel. "ARHGAP4 is a spatially regulated RhoGAP that inhibits NIH/3T3 cell migration and dentate granule cell axon outgrowth." Connect to text online, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1183470294.
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Friedman, Rachel Ann. "Investigation of C-Reactive Protein and Leptin as Biomarkers of Obesity with Potential Clinical Utility." TopSCHOLAR®, 2011. http://digitalcommons.wku.edu/theses/1091.
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Obesity and its subsequent disease states are major health problems in the United States. In many ways, obesity can be considered a “disease state” itself due to the changes it causes on the body. High-intensity exercise also places acute stress the body, putting humans in recovery from exercise in a state that may be analogous to a temporary disease state. The purpose of this study was to examine biomarkers associated with obesity (CRP and Leptin) before and after continuous and intermittent bouts of exercise in an obese but otherwise healthy sample vs. a healthy, non-obese sample. This investigation focused on examining the obese sample’s biomarkers at rest compared to those of the healthy group immediately and 1 hour-post exercise. Eighteen male subjects participated, with nine in each group. Each subject performed a VO2 max test and a series of three anaerobic Wingate tests at least one week apart in a cross-over study design. Blood was taken at baseline, immediately-post, and 1-hour post for each exercise mode. A significant difference was noted between groups for CRP at baseline on the VO2 testing day. A significant difference between groups existed in leptin levels at baseline on both testing days. The only significant change was the decrease in leptin from post to 1- hour post for during the VO2 in the obese group. However, both exercise protocols demonstrated various effects on the subjects and groups. Healthy participants were examined individually, and two of them showed possible signs of being at risk for obesity and its subsequent disease states based on post exercise “spikes” in CRP and leptin that caused the levels of the biomarkers to be closer to those in the obese group at rest. Another three subjects saw at least two spikes. Thus, a total of five subjects could potentially be “at-risk” based on the assumptions of the present study. These results suggest CRP and Leptin could potentially hold the ability to classify someone in a “preobesity state.” Further investigations are warranted based on these initial results and should focus on biomarkers more specific to obesity.
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Easley, Charles Allen. "Fibronectin-dependent activation of CaMK-II promotes focal adhesion disassembly by inducing tyrosine dephosphorylation of FAK and paxillin /." Unavailable until 8/19/2013, 2008. http://hdl.handle.net/10156/2272.
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Clemmens, John Scott. "Engineering surfaces for directed motion of motor proteins : building a molecular shuttle system /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/8024.
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Peiró, Morell Ana. "Proteínas de movimiento de la familia 30K:interacción con membranas biológicas y factores proteicos y su implicación en el transporte viral." Doctoral thesis, Universitat Politècnica de València, 2015. http://hdl.handle.net/10251/48471.
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Para que el proceso infeccioso de un virus de plantas tenga éxito la progenie
viral tiene que propagarse desde las primeras células infectadas al resto de la planta;
inicialmente se moverá célula a célula a través de los plasmodesmos (PDs) hasta
alcanzar el sistema vascular, lo cual le permitirá invadir las partes distales de la planta.
En este proceso, las proteínas de movimiento (MPs), junto con la colaboración de otros
actores secundarios, desempeñan un papel relevante. El conocimiento de la posible
asociación de las MPs con estructuras u orgánulos celulares así como de la interacción
con factores del huésped es de vital importancia para poder desarrollar estrategias
antivirales que permitan una mejora en la producción de los cultivos. Además, este tipo
de estudios no sólo han posibilitado un mayor conocimiento de las respuestas al estrés
en plantas sino que han sido pioneros en desentrañar los mecanismos de translocación
intercelular de factores celulares implicados en los procesos de desarrollo de las
plantas.
Las MPs virales se clasifican en familias/grupos en función de su grado de
similitud. Los virus, cuyas MPs pertenecen a la Superfamilia 30K, expresan una única MP
encargada de orquestar el movimiento intra- e intercelular de genoma viral. En el
Capítulo 1 de la presente Tesis se ha caracterizado la asociación de la MP del Virus del
mosaico del tabaco (TMV), miembro tipo de la familia 30K, al sistema de
endomembranas. Mediante el uso de aproximaciones in vivo se ha estudiado la
eficiencia de inserción de sus regiones hidrofóbicas (HRs) en la membrana del retículo
endoplasmático (ER). Nuestros resultados demuestran que ninguna de las dos HRs de la
MP es capaz de atravesar las membranas biológicas y que la alteración de la
hidrofobicidad de la primera HR es suficiente para modificar su asociación a la
membrana. En base a los resultados obtenidos, proponemos un modelo topológico en
el cual la MP del TMV se encontraría fuertemente asociada a la cara citosólica de la
membrana del ER, sin llegar a atravesarla. La observación de que i), el modelo
propuesto es compatible con otros motivos, previamente caracterizados, de la MP de
TMV y ii), concuerda con la topología descrita para otras MPs de la familia 30K, permite
cuestionar el modelo establecido desde el año 2000 para la MP de TMV así como
predecir, en base a la conservada estructura secundaria de las MPs de esta familia, una
topología similar para todos sus componentes.
Para el transporte intercelular de los virus de plantas se han descrito tres
modelos en base a la capacidad de transportar complejos ribonucloeprotéicos, a través
de PD modificados, formados por el RNA viral y la MP (ej. MP de TMV) más la proteína
de cubierta (ej. MP del virus del mosaico del pepino, CMV) o la capacidad de transportar
viriones a través estructuras tubulares formadas por la MP (ej. MP del Virus del mosaico
del caupí, CPMV). A pesar de las diferencias observadas entre los tres modelos, las MPs
representativas de cada uno de ellos pertenecen a la misma familia 30K y son
funcionalmente intercambiables (MPs de TMV, CMV, CPMV, Virus del mosaico del
Bromo -BMV- o Virus de los anillos necróticos de los prunus -PNRSV-) por la MP del Virus
del mosaico de la alfalfa (AMV), para el transporte a corta distancia. Con el objeto de
comprender la versatilidad que presentan las MPs en cuanto al movimiento viral,
hemos analizado la capacidad de estas MPs heterólogas de transportar sistémicamente
el genoma quimérico del AMV. El estudio ha revelado que todas las MPs analizadas
permiten el transporte del genoma quimera a las partes distales de la planta,
independientemente del modelo descrito para el transporte a corta distancia, aunque
requieren la extensión de los 44 aminoácidos C-terminales de la MP del AMV. Además,
para todas las ellas, excepto para la MP del TMV, se ha establecido una relación entre la
capacidad de movimiento local y la presencia del virus en las hojas no inoculadas de la
planta, indicando la existencia de un umbral de transporte célula a célula, por debajo
del cual, el virus es incapaz de invadir sistémicamente la planta.
Durante el proceso de infección viral, las MPs interaccionan tanto con otras
proteínas de origen viral como de la planta huésped. La interacción entre las MPs y
dichos factores de la planta afectan a la patogénesis viral, facilitando u obstaculizando
el movimiento intra- o intercelular del virus. En el Capítulo 3 del presente trabajo hemos
demostrado la interacción entre la MP del AMV y dos miembros de la familia de
Patellinas de arabidopsis, Patellin 3 (atPATL3) y Patellin 6 (atPATL6), mediante el
sistema de los dos híbridos de levadura y ensayos de reconstitución bimolecular de la
fluorescencia. Nuestros resultados, en general, demuestran que la interacción entre la
MP-PATLs obstaculizaría un correcto direccionamiento de la MP al PD, dando lugar a un
movimiento intracelular menos eficiente de los complejos virales, que forma la MP, y
disminuyendo el movimiento célula a célula del virus. Podríamos estar hablando de un
posible mecanismo de defensa de la planta, dirigido a evitar la invasión sistémica del
huésped. En este sentido, las MPs virales pueden ser buenos candidatos para el
desarrollo de estrategias antivirales dado que cualquier respuesta de defensa de la
planta que, a priori, reduzca el transporte célula a célula del virus, puede representar la
diferencia entre una infección local o sistémica, como hemos observado en el Capítulo 2
del presente trabajo. Los virus, a su vez, también son capaces de evolucionar hacia
variantes más eficaces, que permitan superar las diferentes barreras defensivas de la
planta huésped. En este contexto hemos identificado a la MP del Virus del bronceado
del tomate (TSWV) como determinante de avirulencia en la resistencia mediada por el
gen Sw-5. Del mismo modo, comprobamos que el cambio de 1-2 residuos de amino
ácidos de la MP de TSWV fue suficiente para superar la resistencia pero que a la vez, y
posiblemente debido a las altas restricciones que conlleva el reducido genoma de un
virus, afectaron a la eficiencia de la MP.Peiró Morell, A. (2014). Proteínas de movimiento de la familia 30K:interacción con membranas biológicas y factores proteicos y su implicación en el transporte viral [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48471
TESIS
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Houalla, Tarek. "Nuclear translocation in the Drosophila eye disc : an inside look at the role of misshapen and the endocytic-recycling traffic pathway." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111894.
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The main focus of my PhD studies was aimed at understanding the general mechanism of nuclear translocation and isolating novel components of the nuclear translocation pathway in neurons. Using the Drosophila visual system as an in vivo model to study nuclear motility in developing photoreceptor cells (R-cells), I have identified a novel role for the Ser/Thr kinase Misshapen (Msn) and the endocytic trafficking pathway in regulating the nuclear translocation process.The development of R-cells in the Drosophila eye disc is an excellent model system for the study of nuclear motility owing to its monolayer organization and the stereotypical translocation of its differentiating R-cell nuclei along the apical-basal plane. Prior to my thesis work, several laboratories had identified dynein and its associating proteins in R-cell nuclear translocation, however nothing was known about the signalling pathway that controlled their function in nuclear migration. Thus, one of my thesis goals was to elucidate the signalling mechanism controlling nuclear translocation in R-cells.
Using a combination of molecular and genetic approaches, I identified Msn as a key component of a novel signalling pathway regulating R-cell nuclear translocation. Loss of msn causes a failure of R-cell nuclei to migrate apically. Msn appears to control R-cell nuclear translocation by regulating the localization of dynein and Bicaudal-D (Bic-D). My results also show that Msn enhances Bic-D phosphorylation in cultured cells, suggesting that Msn regulates R-cell nuclear migration by modulating the phosphorylation state of Bic-D. Consistently, my results show that a Bic-D-phosphorylation-defective mutation disrupted the apical localization of both Bic-D and dynein. I propose a model in which Msn induces the phosphorylation of Bic-D, which in turn modulates the activity and/or subcellular localization of dynein leading to the apical migration of R-cell nuclei.
In addition to studying Msn, I have also searched for additional players in R-cell nuclear migration. From a gain-of-function approach, I found that the misexpression of the GTPase-activating-protein (GAP) RN-Tre caused a severe defect in R-cell nuclear migration. Since mammalian RN-Tre is involved in negatively regulating Rab protein activity, I speculated that the RN-Tre misexpression phenotype reflected a role for Rab-mediated vesicular transport in regulating R-cell nuclear migration. I systematically examined the potential role of Rab family proteins in R-cell nuclear migration and found that interfering with the function of Rab5, Rab11 or Shibire caused a similar nuclear migration phenotype. I propose that an endocytic pathway involving these GTPases is required for the targeting of determinants to specific subcellular locations, which in turn drive the apical migration of R-cell nuclei during development.
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Chen, Weiwei. "Characterization of the movement of a circadian protein in the temperature-dependent root synchronization of Arabidopsis thaliana." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670449.
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El rellotge circadià està sincronitzat per senyals mediambientals externes, principalment la llum i la temperatura. Entendre com respon el rellotge circadià de la planta a les oscil·lacions de temperatura és crucial per comprendre la capacitat de resposta de la planta a l'entorn. En aquesta tesi doctoral, trobem una funció prevalent depenent de la temperatura de l'component de el rellotge d'Arabidopsis EARLY Flowering 4 (ELF4) en el rellotge circadià de l'arrel. En plantes en les quals l'àpex aeri s'ha eliminat, el rellotge pot funcionar en les arrels, tot i que exhibeix un període més curt i una fase avançada en comparació amb les arrels de plantes completes. Els assajos de microempelt mostren que ELF4 es mou des de l'àpex aeri per regular els ritmes en les arrels. El moviment de la proteïna ELF4 no transmet informació fotoperiòdica, sinó que és essencial per controlar el període de el rellotge circadià en l'arrel d'una manera depenent de la temperatura. Les baixes temperatures afavoreixen la mobilitat de ELF4, el que resulta en un rellotge de de ritme lent, mentre que les altes temperatures disminueixen el moviment, el que porta a un rellotge més ràpid. Per tant, el moviment de la proteïna ELF4 mòbil proporciona informació sobre la temperatura i ajuda a establir un diàleg entre l'àpex aeri i l'arrel de la planta per controlar el ritme circadià en l'arrel.El reloj circadiano está sincronizado por señales medioambientales externas, principalmente la luz y la temperatura. Entender cómo responde el reloj circadiano de la planta a las oscilaciones de temperatura es crucial para comprender la capacidad de respuesta de la planta al medio ambiente. En esta Tesis Doctoral, encontramos una función prevalente dependiente de la temperatura del componente del reloj de Arabidopsis EARLY FLOWERING 4 (ELF4) en el reloj circadiano de la raíz. En plantas en las que el ápice aéreo se ha eliminado, el reloj puede funcionar correctamente en las raíces, aunque exhibe un período más corto y una fase avanzada en comparación con las raíces de plantas completas. Los ensayos de microinjerto muestran que ELF4 se mueve desde el ápice aéreo para regular los ritmos en las raíces. El movimiento de la proteína ELF4 no transmite información fotoperiódica, sino que es esencial para controlar el período del reloj circadiano en la raíz de una manera dependiente de la temperatura. Las bajas temperaturas favorecen la movilidad de ELF4, lo que resulta en un reloj de de ritmo lento, mientras que las altas temperaturas disminuyen el movimiento, lo que lleva a un reloj más rápido. Por lo tanto, el movimiento de la proteína ELF4 móvil proporciona información sobre la temperatura y ayuda a establecer un diálogo entre el ápice aéreo y la raíz de la planta para controlar el ritmo circadiano en la raíz.
The circadian clock is synchronized by external environment cues, mostly through light and temperature. Explaining how the plant circadian clock responds to temperature oscillations is crucial to understanding plant responsiveness to the environment. In this thesis, we found a prevalent temperature-dependent function of the Arabidopsis clock component EARLY FLOWERING 4 (ELF4) in the root clock. The clocks in roots are able to run properly in the absence of shoots although shoot excision leads to a shorter period and advanced phase in excised roots compared to entire roots. Micrografting assays show that ELF4 moves from shoots to regulate rhythms in roots. ELF4 movement does not convey photoperiodic information, but trafficking is essential for controlling the period of the root clock in a temperature-dependent manner. Low temperatures favour ELF4 mobility, resulting in a slow paced root clock, whereas high temperatures decrease movement, leading to a faster clock. Hence, the mobile ELF4 delivers temperature information and establishes a shoot-to-root dialogue that sets the pace of the clock in roots.
Universitat Autònoma de Barcelona. Programa de Doctorat en Biologia i Biotecnologia Vegetal
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Bialas, Brian Henry. "Safety in petroleum movement : is enough being done to protect the environment?" Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/28511.
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Webster, Sarah. "Protest activity in the British student movement, 1945 to 2011." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/protest-activity-in-the-british-student-movement-1945-to-2011(0111ba06-9b2d-468c-9bf0-11b938b15d37).html.
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This thesis examines the historical pattern of protest activity involving students from the University of Manchester and the London School of Economics between the academic years 1945/46 and 2010/11. Gathered through a protest event analysis of the universities’ student press, quantitative protest event data is presented that establishes a continuous pattern of protest activity at both institutions from the mid-fifties onwards. Adding to a small body of scholarship on student activism beyond the sixties epoch, the thesis challenges the assumption that student protest peaked in the late sixties, which currently dominates the student protest literature. The decade’s wave of student unrest is widely presented as exceptional and unprecedented, a golden age of student protest, casting non-sixties student generations as politically apathetic. The quantitative data refutes these claims, demonstrating an ongoing history of student protest on both campuses that sets precedent for the sixties mobilisations and undermines the idea that student apathy is pervasive on the post-sixties university campus. Between 1945/46 and 2010/11, University of Manchester students are involved in 840 protest events, while London School of Economics students participate in 505 protest events, a combined total of 1345 protest events. Using qualitative data drawn from the student press and other archival materials alongside the numeric data, the thesis argues that the British student unrest in the sixties had precedent in the fifties and early sixties, noting tactical and ideological similarities. Further, the thesis refutes the student apathy narrative using protest activity as evidence of student political participation, but also pointing to student engagement in formal and informal political activity, such as political party membership, voluntary action and campaigning for NGOs and pressure groups. Echoing studies on youth political participation, the thesis finds that students remain politically engaged across the twentieth and twenty-first century. Drawing together social movement theory with insights from the archival materials and student press, the thesis identifies factors contributing to the emergence, decline and survival of student protest activity at the University of Manchester and London School of Economics. The thesis establishes that progressive political and social values, student produced movement frames, access to resources on campus, political opportunities and campus activist networks interact to facilitate the emergence of student unrest. It also demonstrates that political factionalism and some forms of authority responses to unrest are key factors in declines in student protest activity. The thesis argues that attempts at co-option and repression by the state and the university, normally understood to prompt declines in protest, may actually provoke further activity amongst students. Applying Nella Van Dyke’s theory of ‘hotbeds of activism’ to the British context (1998), the thesis argues protest activity survives across the timeframe, because both universities have developed student activist networks and subcultures that maintain the traditions and practices of activism on campus. Activist expertise is transferred between student generations through the student unions, student societies and informal groupings, ensuring that that the campus activist networks are primed to seize opportunities for protest activity on and off campus.
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Lee, Chih-ying. "Bouquet formation, rapid prophase movements and homologous pairing during meiotic prophase in Saccharomyces cerevisiae." Oklahoma City : [s.n.], 2009.
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Akamatsu, Naoko. "Studies on the Regulation of Function of Brome mosaic virus 3a Movement and Coat Proteins." Kyoto University, 2008. http://hdl.handle.net/2433/123957.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第14057号
農博第1727号
新制||農||961(附属図書館)
学位論文||H20||N4395(農学部図書室)
UT51-2008-F449
京都大学大学院農学研究科応用生物科学専攻
(主査)教授 奥野 哲郎, 教授 遠藤 隆, 教授 佐久間 正幸
学位規則第4条第1項該当
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Garton, Kyle Justin. "The ADAMs : a novel family of cell surface proteins with adhesive and protease activity /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/6313.
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Lee, Myung Soo. "Studies on the DNA helicase activities of the Escherichia coli primosome : involved in DNA replication fork movement /." Access full-text from WCMC, 1989. http://proquest.umi.com/pqdweb?did=744115351&sid=1&Fmt=2&clientId=8424&RQT=309&VName=PQD.
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Jiang, Hao. "Investigation of the functional and biological properties of the movement proteins of monopartite and bipartite begomoviruses /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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MIYAKE, KOJI, YOSHIKAZU TSUJI, HATSUKI HIBI, and MASANORI YAMAMOTO. "EFFECTS OF PROTEIN SYNTHESIS INHIBITOR AND ANTIMICROTUBULAR AGENT ON TRANSEPITHELIAL MOVEMENT OF 3H-ANDROGENS IN THE RAT CAPUT EPIDIDYMIS." Nagoya University School of Medicine, 1994. http://hdl.handle.net/2237/16073.
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Meckfessel, Matthew Harold. "Identification of Three Symbiosome Targeting Domains in the MtENOD8 Protein and Cell-to-cell MtENOD8 mRNA Movement in Nodules." Thesis, University of North Texas, 2012. https://digital.library.unt.edu/ark:/67531/metadc115118/.
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The model legume, Medicago truncatula, is able to enter into a symbiotic relationship with soil bacteria, known as rhizobia. This relationship involves a carbon for nitrogen exchange in which the plant provides reduced carbon from photosynthesis in exchange for reduced, or “fixed” atmospheric nitrogen, which allows the plant to thrive in nitrogen depleted soils. Rhizobia infect and enter plant root organs, known as nodules, where they reside inside the plant cell in a novel organelle, known as the symbiosome where nitrogen fixation occurs. the symbiosome is enriched in plant proteins, however, little is known about the mechanisms that direct plant proteins to the symbiosome. Using the M. truncatula ENOD8 (MtENOD8) protein as a model to explore symbiosome protein targeting, 3-cis domains were identified within MtENOD8 capable of directing green fluorescent protein (GFP) to the symbiosome, including its N-terminal signal peptide (SP). the SP delivered GFP to the vacuole in the absence of nodules suggesting that symbiosome proteins share a common targeting pathway with vacuolar proteins. a time course analysis during nodulation indicated that there is a nodule specific redirection of MtENOD8-SP from the vacuole to the symbiosome in a MtNIP/LATD dependent manner. GFP expression by the MtENOD8 promoter revealed spatial discrepancy between promoter activity and protein localization. in situ localization of MtENOD8 mRNA showed localization to infected cells, where the protein is found, suggesting mRNA cell-to-cell movement. Expression of MtENOD8 in Arabidopsis showed that the SP did not direct GFP to the vacuole indicating that vacuolar targeting of MtENOD8’s SP may be legume specific. Taken together, the research presented here indicates that the MtENOD8 symbiosome protein has evolved redundant domains for targeting, which has part of a common pathway with vacuolar proteins. Observed spatial discrepancy between the MtENOD8 promoter and protein shows additional mechanisms of gene regulation through cell-to-cell mRNA movement, previously unknown in nodules.