Dissertations / Theses on the topic 'Cell migration Nuclear envelope'
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KIDIYOOR, GURURAJ RAO. "ATR MEDIATED REGULATION OF CELLULAR AND NUCLEAR PLASTICITY." Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/561090.
Full textJaffer, Ali Mohammed Hakim. "Multifaceted roles of the transmembrane nuclear envelope protein, Samp1." Doctoral thesis, Stockholms universitet, Institutionen för neurokemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-141816.
Full textAt the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript.
Sabbatini, G. P., and G. P. Sabbatini. "Rat liver nuclear envelope insulin binding and its effects on endogenous protein kinases." Doctoral thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/23361.
Full textBermeo, Serrato Sandra Milena. "Role of the Proteins of the Nuclear Envelope in Mesenchymal Stem Cell Differentiation." Thesis, The University of Sydney, 2015. http://hdl.handle.net/2123/14373.
Full textBERTORA, STEFANIA. "ROLE OF NUCLEAR ENVELOPE PROTEIN MAN1 IN NUCLEAR ORGANISATION AND MAINTENANCE OF GENOME STABILITY." Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/554706.
Full textAnna, Newman-Griffis Hare. "Plant nuclear envelope-associated proteins function in development and symbiosis." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1542733901078983.
Full textHattier, Thomas. "Investigation of Laminopathy-Like Alterations of the Nuclear Envelope caused by Accumulation of Esc1p." Case Western Reserve University School of Graduate Studies / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=case1138383986.
Full textChemudupati, Mahesh. "Investigating the effects of nuclear envelope proteins on nuclear structure and organization in Aspergillus nidulans." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu148009978216118.
Full textWylde, George William. "Mechanotransduction at the nuclear envelope : the role of forces in facilitating embryonic stem cell fate decisions." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/267909.
Full textVollmar, Friederike Lara Veronika. "Analyse der Kernhüllenbildung am Modellsystem Xenopus laevis = Studying nuclear envelope assembly in the cell-free system derived from Xenopus laevis eggs." kostenfrei, 2008. http://www.opus-bayern.de/uni-wuerzburg/volltexte/2009/2929/.
Full textFousse, Julie. "Study of the coupling between interkinetic nuclear migration and cell-cycle progression in the mouse developing cortex." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1320.
Full textXu, Xianfeng. "Two sides of the plant nuclear pore complex and a potential link between Ran GTPase and plant cell division." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1190050471.
Full textDinh, Kristie Nhi. "Interleukin-2 Receptor Alpha Nuclear Localization Impacts Vascular Smooth Muscle Cell Function and Phenotype." Wright State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=wright1630243625985423.
Full textLiu, Jianmin. "Structural investigation of the complex of filamin a repeat 21 with integrin aIIb & ß₃ cytoplasmic tails a potential "transmission" to regulate cell migration /." Cleveland, Ohio : Cleveland State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1263314406.
Full textAbstract. Title from PDF t.p. (viewed on Feb. 1, 2010). Includes bibliographical references (p. 104-114). Available online via the OhioLINK ETD Center and also available in print.
Nanjundappa, Rashmi Rudrappa [Verfasser], Angelika A. [Akademischer Betreuer] Noegel, and Siegfried [Akademischer Betreuer] Roth. "Nesprin-2 Giant at the nuclear envelope with roles in cell differentiation, proliferation and chromatin association / Rashmi Rudrappa Nanjundappa. Gutachter: Angelika A. Noegel ; Siegfried Roth." Köln : Universitäts- und Stadtbibliothek Köln, 2011. http://d-nb.info/1038065860/34.
Full textHolzinger, Andreas. "Exploring the cellular mechanisms that control cell shape formation, nuclear migration and chloroplast adaptations to environmental conditions in algae and higher plants." Dortmund Schwerte, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=2922989&prov=M&dok_var=1&dok_ext=htm.
Full textIsaac, Jared. "Studies of Protein S-nitrosylation in Prostate Cancer focused on Integrin Alpha 6, Proliferating Cell Nuclear Antigen and Estrogen Receptor Beta." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1342543634.
Full textOliveira, Ana Filipa Martins. "Microglial clearance function: dependence on phenotypes." Master's thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/6715.
Full textMicroglia are active sensors of the brain and respond promptly to even minor disturbance in their microenvironment. A feature of this response is the accumulation of these cells at the site of lesion. Neonatal jaundice is a common condition of the newborn and may determine injury to neurons and glial cells, such as microglia, when levels of unconjugated bilirubin (UCB) are excessive. With the objective to evaluate whether microglia have a protective or deleterious role, we decided to assess, using the Boyden chamber, the chemotactic effect of free unbound UCB (fUCB), as well as the migration ability of UCB-treated microglia in the absence or in the presence of chemotatic compounds, such as ATP and S100B. Also, we intended to evaluate the effect of glycoursodeoxycholic acid (GUDCA) as a modulator. To characterize our usual model of microglia isolation, phenotypic evaluation of cultures with different days in vitro (DIV) was performed by estimating cell morphology, nuclear factor-kappaB (NF-κB) activation and phagocytic ability. We observed that fUCB did not act as a chemotactic compound for microglia and that cells treated with UCB showed decreased migration ability. Co-incubation with GUDCA prevented this effect and enhanced microglia migration. However, reduced effects were observed in the presence of ATP and abolished when using S100B. Isolated microglia with 2 DIV showed features of activation, but presentedramified morphology of the “resting” state, less NF-κB activation and increased phagocytosis at 13 DIV. Data indicate that microoglia exposure to UCB leads to a reduced migration ability and that co-incubation with GUDCA prevents this deleterious effect, resulting in an increased migration. Characterization of microglia phenotypes, along the time in culture, point to 13 DIV cells as the most suitable for studies intended to evaluate microglia reactivity to UCB, and probably to other stimuli.
Morelli, E. "NOVEL FUNCTIONS OF THE SNARE PROTEIN SNAP29IN MEMBRANE TRAFFICKING AND CELL DIVISION." Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/265475.
Full textDazzoni, Régine. "Unravelling the role of Nuclear Membrane dynamics in the behaviour of cancer cells : A multidisciplinary approach using cell biology, advanced imaging and biophysics." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0310.
Full textMuscular dystrophy diseases, breast and kidney cancers are linked to malformation of the nuclear envelope (NE). Mechanisms involved in the maintenance of NE morphology are based on proteo-lipid interactions. Recently, the physical properties of specific lipids has highlighted their essential role in NE assembly process of a sea urchin model. To provide molecular insight in how the nuclear architecture is regulated, we used Mass spectrometry and Nuclear Magnetic Resonance (NMR) as quantitative methods to investigate the lipid composition and the dynamics of the NE. Nuclei extraction were performed from HEK 293T human kidney cells. A physical extraction based on a pressure treatment and a sucrose gradient was used and improved considerably the nuclei yield, and afforded obtaining a high quantity of intact nuclei (NE lipids) required for experiments, with a minimum of cell debris, or the ER and Golgi compartments. The nuclear lipids were then extracted from the pure nuclei using a modified Folch method. Liquid-state NMR experiments showed that the NE is composed of a complex mixture of phospholipids and with phosphatitylcholine present in a higher proportion compared to other membrane organelles. Furthermore, an unusual proportion of phosphatidylinositol has been found at the NE. Mass spectrometry experiments have shown that the composition of phospholipids is dominated by species with greatky unsaturated chains with an average length of 34 carbons. Reconstructed nuclear lipid extract membranes were analysed by solid-state NMR and exhibit atypical physical properties. The lamellar gel-fluid phase transition temperature was found very low and broad at -10 15°C, possibly due to the presence of numerous lipid species and unsaturated acyl chains. Furthermore, at 25°C, reconstructed nuclear lipid membrane was found to be more rigid than classical model membranes suggesting a larger bilayer thickness. Finally, reconstructed nuclear lipid liposomes have shown a very important prolate deformation in a magnetic field, which is unusual for biological membranes and suggests an important curvature elasticity for the membrane
Deveraux, Solenne. "Modélisation de la mécanique de la cellule et son noyau dans le cadre de la migration confinée." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLC063/document.
Full textOne of the fundamental properties incells is their ability to migrate. Fromembryogenesis to tumor metastasis, migratingcells must overcome mechanical obstacles toreach their intended location, squeezing throughsub-cellular and sub-nuclear gaps. It can be doneby adapting the locomotion mode to thesurrounding environment or by tuning the cell’sown mechanical properties. Migrating in aconfined space leads to intensive deformation ofthe cell and thus its nucleus. Being the largestand stiffest organelle, the nucleus can hamperthe migratory process. Its mechanical propertieshence are key to a successful migration in acomplex environment. Molecular signals behindcell migration have been extensively studied inthe literature, but what can computationalmechanics modeling unveil about themechanisms behind cell migration?Cell migration is such a complex mechanobiologicalprocess, that all aspects cannot bemodeled at once for now. We choose threedistinct situations for in-depth study. We firstseek to understand the mechanical interplaybetween the nucleus and the cytoplasm, sincenuclear plasticity seems decisive for migrationthrough sub-nuclear gaps. Second, weinvestigate the mechanics of chimneying, aspecific confined migratory mode, in which noadhesion in needed for the cell to move forward.Poroelasticity, coupled with friction, appears asthe key to successful locomotion. Eventually,cell spreading on micro-pillared substrates hasrecently been developed to study nuclearmechanical properties. The mechanism behindthis process being however unclear, we designeda large deformation model to determine whetherthe nucleus is being pushed or pulled in theinter-pillars gaps
Aureille, Julien. "Mécanotransduction au cours du cycle cellulaire : Rôle de la déformation de l'enveloppe nucléaire." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAV072/document.
Full text.The shape of the cell nucleus can vary considerably during developmental and pathological processes as a consequence of the mechanical forces emanating from the microenvironment or generated by the cytoskeleton. However the impact of nuclear morphology on the transcriptional machinery is not known. Using a combination of tools to manipulate the nuclear morphology, we observed that changes in nuclear shape regulate the activity of AP1 and TEAD. We showed that nuclear flattening increases c-Jun phosphorylation and YAP nuclear translocation, leading to transcriptional induction of AP1 and TEAD-target genes. Surprisingly, we found that nuclear compression is necessary and sufficient to mediate c-Jun and YAP activation in response to cell- generated contractility or cell spreading. We additionally observed that nuclear flattening occurs during the cell cycle and promotes proliferation via TEAD and AP1- dependent G1 to S progression
Anthis, Nicholas J. "Structural studies of integrin activation." Thesis, University of Oxford, 2009. http://ora.ox.ac.uk/objects/uuid:caf0f76f-b05a-4b72-8394-5f24de3fd5df.
Full textCollins, Patrick. "The Characterisation of Putative Nuclear Pore-Anchoring Proteins in Arabidopsis thaliana." Thesis, University of Canterbury. Biological Sciences, 2013. http://hdl.handle.net/10092/8885.
Full textHuang, Rong. "The role of MSCs in immunoregulation of macrophages during osteogenesis." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/123512/1/Rong%20Huang%20Thesis.pdf.
Full textMartino, Lisa. "Rôle et régulation de la kinase PLK-1 lors de l'entrée en mitose dans l'embryon de Caenorhabditis elegans." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC225.
Full textDuring cell division, a mother cell duplicates (interphase) and then segregate its genetic material equally between the two daughter cells (mitosis). Between these two stages, the cell undergoes a drastic reorganization governed by the major actor Cdk1-Cyclin B, leading to mitotic entry. The activation of this kinase is regulated by an auto-amplification loop where the first molecules of Cdk1-Cyclin B stimulate activation of the following. Plk1 kinase has been shown to initiate this self-amplification loop by stimulating activators and repressing upstream Cdk1-Cyclin B inhibitors. For this kinase to be fully active, it must itself be activated by Aurora A, in the presence of its coactivator Bora. It is crucial to understand how all these actors coordinate in space and time to trigger mitotic entry because a disruption could lead to a segregation of anarchic DNA, leading to the formation of tumors and the appearance of cancers. During my thesis, I first contributed to demonstrate a conserved mechanism of Plk1 activation in human cells and in C. elegans (PLK-1), involving the coactivator Bora or SPAT-1 in C. elegans. We have shown that the phosphorylation of SPAT-1 by Cdk1-Cyclin B induces its interaction with PLK-1, which promotes the phosphorylation of PLK-1 by Aurora A and thus its activation in vitro. This phosphory-dependent mechanism of SPAT-1 is important in vivo for controlling the entry into mitosis over time. In addition, activation of Plk1 in vitro with human proteins strongly suggests conservation of the mechanism. We then showed that the phosphorylation of Bora and SPAT-1 by Cdk1 on residues S41, S112, S137 and S119, S190, T229 respectively, is necessary for their interaction with Plk1 / PLK-1, then triggering the activation of Plk1 / PLK-1 and mitotic entry. These results demonstrate that phosphorylated Bora / SPAT-1 is part of the self-amplification loop of Cdk1-Cyclin B via the activation of Plk1, ultimately enabling irreversible activation of the actors of mitotic entry. Subsequently, I focused on the role of PLK-1 in nuclear envelope breakdown using the C. elegans early embryo as a model system. After demonstrating that PLK-1 is crucial for the nuclear envelope breakdown in embryos, I observed a localization of PLK-1 to the nuclear envelope before its rupture and I identified a nucleoporin complex involved in this process. Indeed, NPP-1, NPP-4 and NPP-11 whose function is to regulate nucleo-cytoplasmic transport, also have a second role in the recruitment of PLK-1 to nuclear pores. PLK-1 interacts with its phosphorylated substrates by two types of Plk1-dependent and independent priming mechanisms, involving another upstream kinase such as Cdk1-Cyclin B for example. I have shown that the recruitment of PLK-1 to the pores depends on both mechanisms, thus requiring coordination between Cdk1-Cyclin B and PLK-1. Once PLK-1 is at the center of the nuclear pore, it can probably phosphorylate many nucleoporins and participate in the disassembly of pores, leading to tnuclear envelope breakdown
Rime, Hélène. "Etude en immunofluorescence des microtubules au cours de la maturation meiotique de l'ovocyte de souris." Paris 6, 1987. http://www.theses.fr/1987PA066201.
Full textPinto, Joana Borrego 1986. "Role of novel nuclear envelope proteins involved in nuclear positioning during cell migration." Master's thesis, 2010. http://hdl.handle.net/10451/2726.
Full textCentrosome reorientation is defined as the positioning of the centrosome in a region between the nucleus and the leading edge and is important for cell polarization and directional cell migration. Cdc42 is the key regulator on this process and two main pathways are involved in centrosome reorientation; on one side, centrosome centration by a mechanism dependent of Par complex and dynein/dynactin, and for other side, a rearward nuclear movement dependent on Cdc42-effector MRCK and actin-myosin retrograde flow. Recently, the LINC complex was found to be involved in the rearward nuclear movement pathway. This complex spans the nuclear envelope and involves a SUN domain-containing protein which interacts with a KASH domain-containing protein, localized in the inner and in the outer nuclear membrane, respectively. SUN proteins bind to lamins and KASH proteins to actin filaments; in this way, the LINC complex makes the connection between actin retrograde flow and the nucleus. In fibroblasts, Sun2 and Nesprin-2 co-localize with dorsal actin cables on TAN lines; actin dorsal cables move back by actin retrograde flow and the nucleus moves with them. Other proteins can be involved in the nuclear movement. In a siRNA screen for nuclear envelope proteins, a putative role for Tmem201 in nuclear movement was identified. In S.pombe, Tmem201 homolog connects the heterochromatin with the LINC complex. A connection with LINC complex in mammalians was never reported so far. Tmem201is a nuclear envelope protein and is localized in TAN lines in fibroblasts. The TMEM201depletion by RNA interference inhibited centrosome reorientation. Tmem201 is involved in nuclear movement, probably by the stabilization of the LINC complex in the nuclear membrane. However, Tmem201 might also be involved in centrosome positioning and could act as a key regulator of both pathways.
Durante muito tempo, o papel do invólucro nuclear foi desvalorizado, sendo visto como um mero compartimento de armazenamento de cromossomas. Hoje em dia, após a descoberta de uma nova categoria de proteínas que permitiram criar o elo entre os componentes nucleares e o citosqueleto, o seu papel como organizador essencial é lhe amplamente reconhecido. De facto, a dinâmica entre citosqueleto e invólucro nuclear é fundamental para um correcto posicionamento do núcleo, que depende, por sua vez, de uma correcta migração e ancoragem do núcleo. O posicionamento nuclear é importante em fenómenos tão diversificados como a fertilização, a formação de fibras musculares, a oogénese e a migração celular. A reorientação do centrossoma é um processo que ocorre em fibroblastos, células endoteliais, células epiteliais, astrócitos, células T e neurónios e que leva à polarização celular. Considera-se que o centrossoma está orientado quando este se encontra posicionado entre o núcleo e a frente condutora da célula na migração. Pensa-se que a polarização do centrossoma é um fenómeno prévio à migração celular, importante para a orientação do Golgi, possibilitando a secreção polarizada de precursores membranares e de factores importantes para a frente da célula, possibilitando a migração. Durante muito tempo, pensou-se que seria o centrossoma a mover-se para uma posição anterior ao núcleo. Hoje em dia, sabe-se que é o núcleo que se move, adquirindo uma posição posterior ao centrossoma. A proteína Cdc42 tem um papel fundamental neste processo, conduzindo à activação dos dois mecanismos necessários à reorientação do centrossoma: por um lado, o centrossoma é mantido no centro da célula. Este mecanismo é dependente do complexo Par (Par6, Par3 e aPKC), da dineína e de dinactina. Por outro lado, MRCK, um efector de Cdc42, activa o movimento retrógrado do núcleo. Este movimento aparece aliado ao movimento retrógrado da actina, dependendo da contracção da miosina. Recentemente, um complexo de proteínas transmembranares do invólucro nuclear foi identificado como fundamental para este movimento nuclear. Este complexo é constituído por duas proteínas, uma com um domínio SUN e a outra com um domínio KASH, ambos localizados na extremidade C-terminal da proteína. Este domínio C-terminal é altamente conservado em todos os Metazoa e em leveduras. A proteína com domínio SUN localiza-se na membrana interna e interage com a lamina nuclear pela sua extremidade N-terminal. A proteína com domínio KASH localiza-se na membrana externa; algumas proteínas que contêm este domínio podem atingir dimensões de mais de 800kDa e podem interagir com a actina pelo seu domínio N-terminal. A localização da proteína com o domínio KASH na membrana externa é absolutamente dependente da proteína com o domínio SUN. Uma grande especulação existe ainda em torno da retenção da proteína com o domínio SUN na membrana nuclear. Em mamíferos, por exemplo, a localização de Sun2 parece ser parcialmente dependente da lamina nuclear, enquanto que Sun1 não depende da lamina para se localizar na membrana nuclear interna. Este complexo atravessa assim todo a membrana nuclear e estabelece assim a ligação entre o núcleo e a actina. Este par proteico é assim chamado de Complexo “LINC” – LIgação entre o Núcleo e o Citosqueleto (LInkers of Nucleoskeleton and Cytoskeleton). Um estudo recente reporta a implicação directa do complexo “LINC” na reorientação do centrossoma em fibroblastos de ratinho. Neste caso, o par de proteínas que está envolvido no movimento nuclear é Sun2/Nesprin-2. Este estudo descreve pela primeira vez a existência de cabos actínicos, organizados numa posição dorsal em relação ao núcleo, que se movem retrogradamente ao mesmo tempo do que o núcleo. Estes cabos, e logo também o movimento retrógrado de actina a eles associados, parecem ser o motor para o movimento nuclear. O envolvimento de Sun2 e Nesprin-2 é reportado, quando se observa que ambas as proteínas se co-localizam com estes cabos de actina e que a depleção destas proteínas inibe o movimento nuclear. Esta associação das proteínas do complexo LINC com os cabos dorsais de actina define uma nova estrutura nuclear denominada de “linhas TAN” – linhas Nucleares Transmembranares associadas a Actina (Transmembrane Actin-associated Nuclear). A força gerada pelo movimento retrógrado de actina é assim transmitida ao núcleo através destas estruturas, conduzindo ao movimento. Sabe-se que Sun2 e Nesprin-2 interagem no espaço perinuclear, mas pouco ainda se sabe sobre esta interacção. Para além do mais, a localização de Sun2 no invólucro nuclear continua mal elucidada. Para além disso, as forças aplicadas sobre estas proteínas durante o movimento nuclear, sugerem o envolvimento de outras proteína na estabilização, organização e interacção deste complexo. Num screen de siRNA para proteínas do invólucro nuclear, algumas proteínas revelaram um potencial papel no movimento nuclear, entre estas a proteína Tmem201. Esta proteína é conservada evolutivamente, estando presente em todos os Metazoa e ainda em S.pombe. Pouco se sabe ainda sobre esta proteína, havendo apenas dois estudos realizados até ao momento, um em S.pombe e outro em células humanas. Em S.pombe, o homólogo de Tmem201, Ima1, participa na associação da heterocromatina com o complexo LINC. Ima1 é importante para a estabilização do complexo, e de facto, quando é eliminada do sistema, observam-se deformações do invólucro nuclear e quebras no complexo LINC. Ima1 funcionará assim como estabilizador do complexo LINC à membrana, função ainda não atribuída a nenhuma outra proteína em mamíferos. Em células humanas, a proteína homóloga Samp1 aparece associada com estruturas membranares que se sobrepõem ao fuso mitótico. É também sugerido um possível papel desta proteína na ligação entre centrossoma e núcleo. Este trabalho propõe-se elucidar o envolvimento da proteína Tmem201 no movimento nuclear e na reorientação do centrossoma. Infelizmente, um anticorpo eficaz para a marcação de Tmem201 não está disponível no mercado e assim, um dos passos fundamentais deste trabalho passou pela produção de um anticorpo capaz de reconhecer eficazmente as três isoformas da proteína. Tal foi conseguido com sucesso, sendo possível visualizar perfeitamente uma marcação nuclear da proteína. Uma marcação a nível dos centrossomas, provavelmente não específica, foi também observada. Esta proteína também foi observada em associação aos cabos dorsais de actina que fazem parte das linhas TAN. Este fenómeno é particularmente interessante, se considerarmos que Sun2 e Nesprin-2 são as duas únicas proteínas que foram identificadas até ao momento com localização nestas estruturas. Tendo em conta que as laminas não se encontram nas linhas TAN, Tmem201 poderia funcionar como estabilizador do complexo LINC a este nível, num papel evolutivamente conservado ao papel de Ima1 em S.pombe. O movimento nuclear e da reorientação do centrossoma pode ser estudado facilmente através de um ensaio experimental em fibroblastos em cultura. Neste ensaio, é efectuado uma lesão linear (através de uma ponta de pipeta) numa monocamda confluente de células aderentes (em meio desprovido de soro). A reorientação do centrossoma é depois estimulada por adição de um factor específico (LPA). Através deste ensaio, procurou-se estudar os efeitos da depleção da proteína, por siRNA, na reorientação do centrossoma. Verificou-se uma inibição da reorientação do centrossoma quando a proteína não está presente, o que corrobora o resultado inicial do screen efectuado. Analisando a posição do centrossoma e do núcleo, uma forte inibição do movimento nuclear é visualizada, enquanto que a posição do centrossoma não é afectada. Os efeitos de depleção podem ser parcialmente recuperados aquando da microinjecção de um plasmídeo que codifica para a mais pequena isoforma de Tmem201 (Tmem201 B-GFP). Os resultados obtidos implicam o envolvimento de Tmem201 no movimento nuclear. Contudo, um resultado inesperado foi obtido, aquando da microinjecção do primeiro domínio da proteína: uma deslocalização do centrossoma. Este resultado sugere um possível envolvimento também no posicionamento do centrossoma. Através dos ensaios de microinjecção, foi também possível concluir que o primeiro domínio da proteína parece estar envolvido na localização nuclear da proteína (visto que Tmem201 628-GFP tem uma localização nuclear), enquanto que o segundo domínio da proteína deverá ter um papel no movimento do núcleo (visto que apenas a Tmem201 B-GFP é capaz de recuperar a reorientação do centrossoma). A inibição do movimento nuclear pode dever-se a diversos factores: se Tmem201 for importante na localização nuclear de proteínas envolvidas no movimento do núcleo, ou se por acaso levar à inibição do movimento retrógrado de actina. Verificou-se que a depleção de Tmem201 não afecta a retenção de Sun2, Nesprin-2, lamin A/C, lamin B e Emerin. Quanto à actina, não parece haver uma alteração do citosqueleto actínico. Em suma, Tmem201 aparece implicada na reorientação do centrossoma, mais precisamente no movimento nuclear. Tendo em conta que não afecta a localização de outras proteínas na membrana nuclear e não altera o citosqueleto actínico, Tmem201 poderá ter um papel como estabilizador do complexo LINC na membrana nuclear, sendo importante para o movimento nuclear. Contudo, poderá também estar envolvida no posicionamento do centrossoma. Tmem201 poderá assim actuar como proteína reguladora das duas vias.
Matchett, K. B., S. McFarlane, S. E. Hamilton, Y. S. A. Eltuhamy, M. A. Davidson, J. T. Murray, A. M. Faheem, and Mohamed El-Tanani. "Ran GTPase in Nuclear Envelope Formation and Cancer Metastasis." 2014. http://hdl.handle.net/10454/10861.
Full textRan is a small ras-related GTPase that controls the nucleocytoplasmic exchange of macromolecules across the nuclear envelope. It binds to chromatin early during nuclear formation and has important roles during the eukaryotic cell cycle, where it regulates mitotic spindle assembly, nuclear envelope formation and cell cycle checkpoint control. Like other GTPases, Ran relies on the cycling between GTP-bound and GDP-bound conformations to interact with effector proteins and regulate these processes. In nucleocytoplasmic transport, Ran shuttles across the nuclear envelope through nuclear pores. It is concentrated in the nucleus by an active import mechanism where it generates a high concentration of RanGTP by nucleotide exchange. It controls the assembly and disassembly of a range of complexes that are formed between Ran-binding proteins and cellular cargo to maintain rapid nuclear transport. Ran also has been identified as an essential protein in nuclear envelope formation in eukaryotes. This mechanism is dependent on importin-β, which regulates the assembly of further complexes important in this process, such as Nup107–Nup160. A strong body of evidence is emerging implicating Ran as a key protein in the metastatic progression of cancer. Ran is overexpressed in a range of tumors, such as breast and renal, and these perturbed levels are associated with local invasion, metastasis and reduced patient survival. Furthermore, tumors with oncogenic KRAS or PIK3CA mutations are addicted to Ran expression, which yields exciting future therapeutic opportunities.
Gonçalves, João Carlos Lima. "Dissecting the mechanisms of dynein recruitment to the nuclear envelope during neocortical development." Doctoral thesis, 2019. http://hdl.handle.net/1822/64689.
Full textThe multi-subunit protein cytoplasmic dynein 1 (dynein) is the major retrograde microtubule motor in the cell. Dynein has multiple roles during brain development and human mutations in dynein-related genes lead to severe neurodevelopmental disorders. In the inner proliferative zones of the neocortex, division of neural stem cells depends on dynein recruitment to the nucleus during interkinetic nuclear migration. Moreover, dynein is required for the multipolar-to-bipolar transition of post-mitotic neurons, and subsequent neuronal migration requires dynein transport of both the nucleus and centrosome to form the layered neocortex. The mechanisms for dynein functional diversity in brain development and in general are unclear. In this work, we used in utero electroporation to deliver cDNAs and shRNAs into the developing rat brain. Analysis was performed by fixed and live imaging 4 days post injection. We found that dynein containing the Light Intermediate Chain 1 subunit is required for neural stem cell proliferation, multipolar-to-bipolar transition and glial-guided neuronal migration. We found no role in the previous mechanisms for Light Intermediate Chain 2-containing dynein, but this dynein population was required for terminal somal translocation of neurons, which was unknown to depend on microtubule motors. Further, our in vitro and in vivo evidence demonstrates that Nesprin-2, a resident protein at the nuclear envelope, recruits dynein via its adaptor BicD2, to mediate nuclear transport during glial-guided neuronal migration. Disruption of Nesprin-2 or BicD2 dynein recruitment caused a severe block in migration, as cells were arrested before reaching the cortical plate. Centrosomal movement appeared intact, but nuclear transport was impaired which led to an increase by more than 50 fold in nucleus-centrosome distance. Overall, our data define discrete dynein populations that contribute differentially to brain development. These data also elucidate the mechanisms for nuclear movement during glial-guided neuronal migration and terminal somal translocation. Ultimately, these advances might help to understand the neurodevelopmental pathologies arising from human mutations in dynein related genes.
A dineína citoplasmática-1 (dineína) é um complexo proteico composto por várias subunidades que desempenha a maioria do transporte retrógrado dependente de microtúbulos na célula. A dineína tem múltiplas funções durante o desenvolvimento cerebral, e no humano mutações em genes que codificam proteínas do complexo causam patologias graves associadas ao neurodesenvolvimento. Nas zonas mais internas do neocórtex embrionário, a proliferação de células estaminais neurais depende do recrutamento de dineína para o núcleo, durante a oscilação nuclear característica destas células. Além disso, a dineína é necessária para a transição morfológica de neurónios multipolares para bipolares, e a subsequente migração neuronal para o córtex requer o transporte do núcleo e do centrossoma pela dineína. Globalmente, os mecanismos da diversidade funcional da dineína não são bem entendidos. Neste trabalho, usamos eletroporação in utero para injetar plasmídeos no cérebro de embriões de ratos, que foram analisados por microscopia confocal 4 dias após a cirurgia. Com isto, descobrimos que a dineína que contém a subunidade Light Intermediate Chain 1 é necessária para a proliferação de células estaminais neurais, para a transição de neurónios multipolares para bipolares, e para a migração neuronal. Não encontramos nenhuma função relevante nos mecanismos anteriores para a subunidade Light Intermediate Chain 2, mas esta população de dineína é fundamental para a terminal somal translocation de neurónios, um processo em que se desconhecia o envolvimento de motores de microtúbulos. Encontramos também através de experiências com imunofluorescência em células e co-imunoprecipitações que a Nesprina-2, uma proteína do invólucro nuclear, recruta dineína através do seu adaptador BicD2. Esta cadeia de interações é importante para a migração neuronal, e quando afetada, os neurónios não conseguem entrar para a Placa Cortical, o precursor embrionário do neocórtex. A disrupção da função da Nesprina-2 ou da BicD2 interrompe o movimento nuclear, mas curiosamente não afeta o transporte do centrossoma. Então as células afectadas apresentam uma separação anormal do núcleo em relação ao centrossoma. Em suma, os nossos dados definem populações específicas de dineína que contribuem de diferente forma para o desenvolvimento cerebral, e ajudam a perceber os mecanimos envolvidos na migração neuronal. Isto é importante para ajudar a entender as patologias do neurodesenvolvimento decorrentes de mutações humanas em genes relacionados com a dineína.
Financial support for this PhD work was provided by FCT (Fundação para Ciência e Tecnologia) fellowship PD/BD/113782/2015, awarded through the University of Minho MD/PhD program.
Lee, Pei Hua, and 李佩樺. "Epstein-Barr Virus Nuclear Antigen 1 Promotes IRS2 Expression and Cell Migration." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/82835405295030141655.
Full textCishek, Dawn M. "Calcium buffer incorporation reversibly inhibits DNA synthesis, nuclear envelope breakdown, and cell division in transformed keratinocytes." 1996. https://scholarworks.umass.edu/dissertations/AAI9638947.
Full textZhu, Ruijun. "Distinct Nuclear-Cytoskeletal LINCages Position the Nucleus for Homeostasis, Polarization and Migration." Thesis, 2017. https://doi.org/10.7916/D8K64WMQ.
Full textLin, Meng Chin, and 林孟瑾. "Investigate the Effect of the Cell Migration Promoted by Epstein-Barr Nuclear Antigen 1." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/46437260120375994291.
Full text長庚大學
生物醫學研究所
103
Epstein-Barr nuclear antigen 1 (EBNA1) is the only viral protein expressed in all EBV-associated tumors, including nasopharyngeal carcinoma (NPC) which is a common malignant disease in Taiwan. However, the role of EBNA1 in cell tumorigenesis has not been well-established. EBNA1 in prototype B95.8 (B-EBNA1) is P-ala subtype. Examination of various Taiwanese EBNA1 clones isolated from NPC (N-EBNA1) and peripheral blood lymphocytes of healthy individuals (P-EBNA1) has demonstrated that they all belonged to V-val subtype but had different sizes in the middle domain (Glycine/Alanine repeat region). The role of different clones of EBNA1 in the NPC oncogenesis is thereby an interesting question remains to be investigated. The preliminary data in the lab indicated that cell migration was promoted by N-EBNA1, but not by P-EBNA1. The migration ability of B-EBNA1 was 2-fold lower than that of N-EBNA1. To further investigate the molecular domains responsible for the migration activity of EBNA1, B- and N-EBNA1 chimeras have been constructed and the results suggested that both of the N- and C-terminus of EBNA1 might play roles in the cell migration. Furthermore, cell migration ability of N-EBNA1 was inhibited by the ROCK inhibitor, Y27632. Collectively, these data suggest that both the N- and C-terminal sequences and sizes of middle domain of EBNA1 are important for the cell migration activity of EBNA1, which might be regulated through the activation of the Rho-ROCK signaling pathway.
You, Guo Rung, and 游國榮. "Nuclear Translocation of NDRG1 by GSK3β-Dependent Phosphorylation Enhances Cell Migration and Invasion in Head and Neck Cancer." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/13542260845670893492.
Full text長庚大學
醫學生物技術暨檢驗學系
99
N-myc downstream regulated gene 1 (NDRG1) is overexpression in head and neck cancer (HNC) tissues as we reported previously. However, the cellular function of this molecule on tumorigenesis of HNC is still not clear. The three-tandem repeats (3R) of ”GTRSRSHTSE” in the C-terminal region of NDRG1 is a specific feature. NDRG1 is predicted phosphorylated at the serine sites in its 3R motif by glycogen synthase kinase 3 β (GSK3β). In this study, we examined the significance of 3R motif of NDRG1 functions leading to HNCs. Expression of the deletion construct NDRG1ΔC [deletion of 3R motif] suppressed nuclear translocation of NDRG1, and led to significantly reduction of cell migration and invasion in HNC cells. We also observed that SB 216763, an inhibitor of GSK3β decreased the phosphorylation of 3R motif of NDRG1 and attenuated the nuclear translocation, cell migration and invasion. We further introduced mutations at the serine sites at 342 [S342A], 352 [S352A] and 362 [S362A], which are susceptible phosphorylation by GSK3β. Expression of all these mutants repressed NDRG1 nuclear import, cell migration and invasion. Together, these results suggest a novel function by which NDRG1 modulates cell motility and invasion through GSK3β phosphorylated serine sites of 3R motif at serine 342, 352 and 362.
Jhan, Jhih Yong, and 詹志勇. "Cell migration promoted by Epstein-Barr Nuclear Antigen 1(EBNA1): Impact of the length of the middle Gly/Ala repeats and the N-and C-terminal amino acid composition of EBNA1." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/93160865625388248675.
Full text長庚大學
生物醫學研究所
101
Epstein-Barr virus nuclear antigen 1 (EBNA1) is the only viral protein detected in all EBV-associated malignant tumors, including nasopharyngeal carcinoma (NPC). To elucidate the role of EBNA1 in NPC, EBNA1 genes, isolated from prototype B95.8 (B-EBNA1, P-ala subtype), NPC samples (N-EBNA1, V-val subtype), and peripheral blood lymphocytes (P-EBNA1, V-val subtype) of healthy individuals in Taiwan, have been cloned and expressed in cultured cells. These EBNA1 clones are different in not only sequences but also sizes, which are determined by the middle Gly/Ala repeats. The role of different clones of EBNA1 in the NPC oncogenesis remains to be investigated. The preliminary data in the lab indicated that cells expressing N-EBNA1 had the best ability to undergo cell migration in a trans-well assay. Therefore, the constructed chimeras between cloned B- and N-EBNA1 sequences and a serial of N-EBNA1 deletion clones with different sizes of middle domain were used here to study the molecular domains responsible for the migration activity of EBNA1. The data obtained from the B- and N-EBNA1 chimeras indicated that the C-terminal of EBNA1 ( aa 487~641 ) played an important role in cell migration. Since amino acids (aa) 502 and 524 are significantly different between B- and N-EBNA1, double mutations at these two specific sites have been constructed. The trans-well data have shown that aa 502 and 524 are crucial for cell migration activity promoted by N-EBNA1. Among seven deletion clones of N-EBNA1, only four of them had the ability to support cell migration. Collectively, these data strongly suggest that both sequences and sizes of middle domain of EBNA1 are important for the cell migration activity of EBNA1. Furthermore, treatment with Rho-kinase (ROCK) inhibitor diminished the cell migration ability of N-EBNA1 indicated that signaling pathway of Rho small GTPases might contribute to the cell migration activity of EBNA1. The connection between the activation of Rho-ROCK pathway by N-EBNA1 and the functional domains of EBNA1 affecting cell migration remains to be investigated.
Xiao, Pei-Yi, and 蕭佩怡. "Epigallocatechin-3-gallate Suppresses Cell Invasion and Migration of Human Lung Cancer Cells through Inhibiting Transforming Growth Factor-β1-Induced β-catenin Nuclear Translocation and the Resulting Epithelial-to-Mesenchymal Transition." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/11794687808648661099.
Full text中山醫學大學
生物醫學科學學系碩士班
101
Transforming Growth Factor (TGF)- β1 may induce epithelial-to-mesenchymal transition (EMT) and cancer invasion via Smad-dependent or -independent signaling pathways. Epigallocatechin-3-gallate (EGCG), the green tea polyphenol, has been reported to block TGF-β1-elicited EMT and invasion of human A549 lung cancer cells in a Smad-dependent manner. Herein, whether EGCG can inhibit TGF-β1-induced EMT and invasion of A549 cells from the modulation of a Smad-independent route was investigated. We found that EGCG suppressed TGF-β1-induced β-catenin nuclear localization and function through inhibiting PI3K/Akt/GSK-3β signaling activation, paralleled with the presence of membrane-bound β-catenin and epithelial marker E-cadherin and the downregulation of aggressive invasion phenotypes of A549 cells. These findings define a new molecular basis that EGCG may block TGF-β1-induced EMT and malignant dissemination of A549 cells through the modulation of a cross-talk between PI3K/Akt/ GSK-3βand Wnt/β-catenin signaling pathways.
Koslová, Anna. "Replikační bloky viru Rousova sarkomu v savčích buňkách." Doctoral thesis, 2017. http://www.nusl.cz/ntk/nusl-370879.
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