• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 349
  • 306
  • 71
  • 25
  • 22
  • 8
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 797
  • 181
  • 162
  • 140
  • 131
  • 127
  • 126
  • 122
  • 111
  • 108
  • 99
  • 98
  • 92
  • 91
  • 91
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Methoden der Belegsammlung für das "Vocabolario della Crusca", exemplarisch vorgestellt am lexikographischen Werk Francesco Redis /

Bielfeld, Antje, January 1993 (has links)
Diss.--Philosophische Fakultät--Saarbrücken--Universität des Saarlandes, 1991.
272

Le parti démocrate-chrétien italien

Godechot, Thierry. January 1964 (has links)
Thèse - Toulouse, 1961. / Without thesis statement. Bibliography: p. [289]-296.
273

Methoden der Belegsammlung für das "Vocabolario della Crusca" : exemplarisch vorgestellt am lexikographischen Werk Francesco Redis /

Bielfeld, Antje, January 1996 (has links)
Diss.--Saarbrück, 1993. / Bibliogr. p. 231-236.
274

L'INSEGNAMENTO ACCADEMICO DELLA PEDAGOGIA IN ITALIA DALLE ORIGINI AGLI ANNI SESSANTA DEL NOVECENTO: IDENTIKIT DEL PROFESSORE ITALIANO DI PEDAGOGIA NELLE UNIVERSITA' MAGGIORI / THE ACADEMIC TEACHING OF PEDAGOGY IN ITALY FROM ITS ORIGINS TO THE SIXTIES OF THE TWENTIETH CENTURY. The identikit of the Italian professor of Pedagogy in major universities

FRIGERIO, CARLOTTA 27 May 2021 (has links)
Il progetto di ricerca che ha condotto alla stesura della mia tesi di dottorato si è posto come obiettivo principale quello di ripercorrere e analizzare la storia dell’insegnamento accademico della Pedagogia nei maggiori atenei italiani, partendo dal periodo preunitario fino ad arrivare agli anni Sessanta del secolo scorso, ricostruendo con esattezza la mappatura delle maggiori cattedre universitarie di Pedagogia, per evidenziarne la loro evoluzione e il loro sviluppo nel tempo. Il primo capitolo di tale elaborato è suddiviso in tre parti: nella prima la ricerca indaga come la storia della Pedagogia accademica sia stata affrontata negli altri paesi europei, dove, ad eccezione dell’Austria con il monumentale lavoro di W. Brezinka, la situazione ricalca quella italiana; nella seconda parte vengono presentati i tre stati italiani preunitari che già proponevano nei loro atenei l’insegnamento della Pedagogia: ovvero il Regno sabaudo a Torino, l’Impero asburgico a Pavia e Padova e il Granducato di Toscana a Pisa; infine l’ultima parte propone un rapido inquadramento legislativo circa l’insegnamento della Pedagogia nelle varie Facoltà e nei differenti percorsi di studio. Il secondo capitolo rappresenta la parte più corposa di tutto il testo poiché passa al vaglio lo sviluppo e l’articolazione della disciplina nei dodici atenei presi in analisi, inquadrando brevemente anche i profili di tutti gli insegnanti incaricati della docenza; esso inoltre presenta anche un’iniziale analisi dei dati in ogni ateneo. Con l’inizio del terzo capitolo il lavoro si concentra sull’analisi quantitativa e qualitativa dei dati raccolti. Esso riporta i grafici riassuntivi corredati da un commento critico degli aspetti indagati ritenuti di maggior importanza ovvero la provenienza geografica dei docenti, l’età dell’ingresso in cattedra, la formazione di ciascun professore, la tipologia d’incarico, i programmi delle lezioni e le correnti pedagogiche e filosofiche abbracciate da ciascun docente; infine il capitolo si conclude con la presentazione di un identikit del professore-tipo di Pedagogia in corrispondenza di quattro principali periodi storici: dall’Unità fino al 1880; dal 1880 alla fine del secolo, dal 1900 alla fine della Seconda Guerra Mondiale e dal periodo post bellico fino al 1960. Da ultimo il quarto capitolo, sebbene abbia una lunghezza ridotta rispetto ai precedenti, consiste nella presentazione della realizzazione di un’applicazione web relativa alla ricerca. In essa è possibile consultare tutti i dati raccolti, ovvero sia l’elenco suddiviso per anni e per facoltà dei professori di Pedagogia nella Facoltà di Lettere e Filosofia, sia le schede biografiche di ciascuno, in modo che siano accessibili da remoto a chiunque ne abbia necessità. Tale tesi è poi corredata da un’Appendice che riporta la schedatura dei numerosi dati raccolti. In conclusione questa analisi a lunga durata ha reso possibile una mappatura storica e geografica circa le permanenze e le fratture che hanno caratterizzato l’insegnamento della Pedagogia accademica in Italia. La Pedagogia è stata per lungo tempo complementare alla Filosofia, inserita nella Facoltà di Lettere e Filosofia; solo nel 1934 è nata la Facoltà di Magistero, ma la disciplina ha mostrato ancora qualche difficoltà a scindersi dalle discipline filosofiche. Inoltre in principio Storia e Didattica della Pedagogia erano unite e il docente di Pedagogia padroneggiava tutto, bisognò attendere gli anni Settanta, con l’esplosione delle cattedre, per assistere alla separazione dei saperi. Concludendo, questo lavoro vuole essere un primo passo nel tentativo di colmare una lacuna della storia della Pedagogia accademica italiana attraverso un’analisi comparativa globale. / The research project that led to the writing of my doctoral thesis had as its main objective that of retracing and analyzing the history of the academic teaching of Pedagogy in the major Italian universities, starting from the pre-unification period until the sixties of the last century, reconstructing with accuracy the mapping of the major university chairs of Pedagogy, to highlight their evolution and their development over time. The first chapter of this work is divided into three parts: in the first one the research investigates how the history of academic Pedagogy has been approached in other European countries, where, with the exception of Austria with the monumental work of W. Brezinka, where the situation is similar to the Italian one; in the second part the three Italian pre-unification states that already proposed the teaching of Pedagogy in their universities are presented: that is, the Savoy Kingdom in Turin, the Habsburg Empire in Pavia and Padua and the Grand Duchy of Tuscany in Pisa; finally the last part proposes a quick legislative framework about the teaching of Pedagogy in the various faculties and in the different courses of study. The second chapter represents the most substantial part of the entire text since it examines the development and articulation of the discipline in the twelve universities under analysis, also briefly framing the profiles of all the teachers in charge of teaching; it also presents an initial analysis of the data in each university. With the beginning of the third chapter, the work focuses on the quantitative and qualitative analysis of the data collected. It shows the summary graphs accompanied by a critical commentary on the aspects investigated that were considered most important, that is, the geographic origin of the teachers, the age at which they entered the professorship, the training of each professor, the type of assignment, the lesson plans and the pedagogical and philosophical currents embraced by each teacher; finally, the chapter concludes with the presentation of a sketch of the typical professor of Pedagogy in correspondence with four main historical periods: Unification to 1880; 1880 to the end of the century; 1900 to the end of World War II; and the post-war period to 1960. Lastly, the fourth chapter, although shorter in length than the previous ones, consists of a presentation of the creation of a web application related to the research. In this application it is possible to consult all the data collected, that is, both the list subdivided by year and by faculty of the professors of Pedagogy in the Faculty of Arts, and the biographical files of each one, so that they can be accessed remotely by anyone who needs them. This thesis is then accompanied by an Appendix that reports the filing of the numerous data collected. In conclusion, this long-term analysis has made possible a historical and geographical mapping of the permanences and fractures that have characterized the teaching of academic Pedagogy in Italy. Pedagogy was for a long time complementary to Philosophy, included in the Faculty of Arts; only in 1934 the Teacher Training Faculty was born, but the discipline still showed some difficulty in splitting from the philosophical disciplines. Moreover, in the beginning, History and Didactics of Pedagogy were united and the teacher of Pedagogy mastered everything; we had to wait until the Seventies, with the explosion of the number of chairs, to see the separation of knowledge. In conclusion, this work wants to be a first step in the attempt to fill a gap in the history of Italian academic Pedagogy through a global comparative analysis.
275

A role for prefoldin in H2A.Z deposition in Arabidopsis

Marí Carmona, Cristina 27 May 2021 (has links)
[ES] El complejo prefoldina (PFDc) participa en la proteostasis celular en eucariotas actuando como cochaperona de la chaperonina CTT. Este papel se ejerce principalmente en el citoplasma, donde contribuye al correcto plegamiento de las proteínas cliente, evitando así que se formen agregaciones y daño celular. Varios informes indican, sin embargo, que también juegan un papel en la regulación transcripcional en el núcleo en varias especies modelo. En este trabajo, hemos investigado cuán extendido es el papel de la PFD en los procesos nucleares al estudiar su interactoma y sus redes de coexpresión en levaduras, moscas y humanos. El análisis indica que pueden realizar una amplia y conservada variedad de funciones en procesos nucleares. La construcción del interactoma predicho para las PFD de Arabidopsis, basado en interacciones ortólogas, nos ha permitido identificar muchos putativos interactores de PFD que los vinculan a procesos no esperados, como la remodelación de la cromatina. Basados en este análisis, hemos investigado el papel de la PFD en la deposición de H2A.Z a través de su interacción con el complejo remodelador de la cromatina SWR1c. Nuestros resultados muestran que la PFD tienen un efecto positivo sobre SWR1c, lo que se refleja en defectos en la deposición de H2A.Z en cientos de genes en plántulas defectuosas en las actividades de PFD3 y PFD5. / [CA] El complex prefoldina (PFDc) participa a la proteostasis cel·lular en eucariotes actuant com co-xaperona de la xaperonina CTT. Aquest paper s'exerceix principalment en el citoplasma, on contribueix al correcte plegament de les proteïnes client, evitant així que es formen agregacions i dany cel·lular. Diversos informes indiquen, però, que també juguen un paper en la regulació transcripcional en el nucli en diverses espècies model. En aquest treball, hem investigat com d'estès és el paper de la PFD en els processos nuclears estudiant el seu interactoma i les seues xarxes de coexpressió en llevats, mosques i humans. L'anàlisi indica que poden realitzar una àmplia i conservada varietat de funcions en processos nuclears. La construcció de l'interactoma predit per a les PFD d'Arabidopsis, basat en interaccions ortòlegs, ens ha permès identificar molts interactors putatius de les PFDs que les vinculen a processos no esperats, com és la remodelació de la cromatina. Amb base en aquest anàlisi, hem investigat el paper de la PFD en la deposició d'H2A.Z a través de la seva interacció amb el complex remodelador de la cromatina SWR1c. Els nostres resultats mostren que les PFDs tenen un efecte positiu sobre SWR1c, que es reflecteix en defectes en la deposició de H2A.Z en centenars de gens en plàntules defectuoses en les activitats de PFD3 i PFD5 / [EN] The prefoldin complex (PFDc) participates in cellular proteostasis in eukaryotes by acting as cochaperone of the chaperonin CTT. This role is mainly exerted in the cytoplasm where it contributes to the correct folding of client proteins, thus preventing them to form aggregations and cellular damage. Several reports indicate, however, that they also play a role in transcriptional regulation in the nucleus in several model species. In this work, we have investigated how extended is the role of PFDs in nuclear processes by inspecting their interactome and their coexpression networks in yeast, fly, and humans. The analysis indicates that they may perform extensive, conserved functions in nuclear processes. The construction of the predicted interactome for Arabidopsis PFDs, based on the ortholog interactions, has allowed us to identify many putative PFD interactors linking them to unanticipated processes, such as chromatin remodeling. Based on this analysis, we have investigated the role of PFDs in H2A.Z deposition through their interaction with the chromatin remodeling complex SWR1c. Our results show that PFDs have a positive effect on SWR1c, which is reflected in defects in H2A.Z deposition in hundreds of genes in seedlings defective in PFD3 and PFD5 activities. / Esta Tesis doctoral ha sido posible gracias al contrato de formación de personal investigador ofrecido por la Universidad Politécnica de Valencia y a la financiación de Pedro J. Marí & Asociados. El proyecto al que pertenece este trabajo ha sido financiado por la Agencia Española de Investigación BIO2013-43184-P y BIO2016-79133-P / Marí Carmona, C. (2021). A role for prefoldin in H2A.Z deposition in Arabidopsis [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/167014 / TESIS
276

"Making Sense of Figures": Statistics, Computing and Information Technologies in Agriculture and Biology in Britain, 1920s-1960s

Parolini, Giuditta <1978> 03 May 2013 (has links)
Throughout the twentieth century statistical methods have increasingly become part of experimental research. In particular, statistics has made quantification processes meaningful in the soft sciences, which had traditionally relied on activities such as collecting and describing diversity rather than timing variation. The thesis explores this change in relation to agriculture and biology, focusing on analysis of variance and experimental design, the statistical methods developed by the mathematician and geneticist Ronald Aylmer Fisher during the 1920s. The role that Fisher’s methods acquired as tools of scientific research, side by side with the laboratory equipment and the field practices adopted by research workers, is here investigated bottom-up, beginning with the computing instruments and the information technologies that were the tools of the trade for statisticians. Four case studies show under several perspectives the interaction of statistics, computing and information technologies, giving on the one hand an overview of the main tools – mechanical calculators, statistical tables, punched and index cards, standardised forms, digital computers – adopted in the period, and on the other pointing out how these tools complemented each other and were instrumental for the development and dissemination of analysis of variance and experimental design. The period considered is the half-century from the early 1920s to the late 1960s, the institutions investigated are Rothamsted Experimental Station and the Galton Laboratory, and the statisticians examined are Ronald Fisher and Frank Yates.
277

La sicurezza nelle organizzazioni aziendali. Un approccio socio-criminologico / Corporate Security. A socio - criminological approach

Tonellotto, Maurizio <1971> January 1900 (has links)
In questa tesi si analizza la sicurezza nelle organizzazioni con un approccio di tipo socio-criminologico. Il presupposto alla base è che la sicurezza sia un bisogno primario dell’uomo, ma anche una necessità per la sopravvivenza delle aziende che operano in un mercato sempre più globale. L’impresa viene vista come una realtà sociale, un micro-organismo sociale in continua interazione osmotica con il mondo esterno, dal quale interscambia costantemente le aspettative, il vissuto, la cultura, le esperienze degli individui, che sono attori sociali dentro e fuori l’impresa stessa. Affrontare il tema della sicurezza non può prescindere dall’analisi delle dinamiche presenti all’interno del perimetro aziendale e, l’assunto lewiniano che relaziona il comportamento umano allo spazio di vita ed alla persona, è stato quindi il leitmotiv di questo progetto. Il disegno della ricerca si sviluppa principalmente da una considerazione, ossia: valutare l’esistenza di un legame tra le dinamiche organizzative e la sicurezza nelle imprese. Si è messo in relazione il costrutto psicologico di Clima Organizzativo a quello di Sicurezza, o meglio ancora,la percezione di sicurezza del lavoratore all’interno del perimetro aziendale. La seconda parte della tesi ripercorre, da un punto di vista più tecnico, lo stato dell’arte della security industriale, esaminandone gli aspetti organizzativi e cercando di inquadrarla anche sotto l’aspetto normativo. In questa sede verrà evidenziata l’importanza della responsabilità sociale d’impresa e dell’applicazione di modelli organizzativi e di gestione che possono garantire, attraverso un approccio etico ed una produzione sostenibile orientata al dipendente ed all’ambiente, migliori condizioni di sicurezza e di lavoro. / This thesis analyzes the corporate-security with a socio-criminological approach. The premise is that security is a basic human need, but also a necessity for the survival of businesses operating in an increasingly global market. The company is seen as a social reality, a micro-social organism in continuous osmotic interaction with the outside world, from which constantly interchanges expectations, experience, culture, experiences of individuals , who are social actors inside and outside the organization. Addressing the issue of security can not be separated from the analysis of the forces operating within the company grounds and the Lewin’s assumption that relate human behavior to the space of life and the person, was the leitmotiv of this project. The research design is developed mainly by a consideration, namely: assessing the existence of a link between dynamics organization and corporate security. The psychological construct of organizational climate has linked to that of Security ( the perception of security of the worker inside the enterprise perimeter). The second part of the thesis traces, from a technical point of view, the state of the corporate security, examining the organizational aspects and also trying to situate it under the regulatory aspect. Here we will highlight the importance of corporate social responsibility (CSR) and the application of organizational and management models that can ensure, through an ethical approach and sustainable production oriented to the employee and to the environment, better security conditions and better work / Cette thèse analyse de la sécurité (security) dans les organisations avec une approche socio- criminologique. La prémisse est que la sécurité est un besoin humain fondamental , mais aussi une nécessité pour la survie des entreprises opérant dans un marché de plus en plus global. La société est considérée comme une réalité sociale , un micro- organisme dans l'interaction sociale osmotique continue avec le monde extérieur , à partir de laquelle cesse les échanges attentes , l'expérience , la culture , les expériences des individus qui sont des acteurs sociaux à l'intérieur et à l'extérieur du entreprise . / En esta tesis se analiza la seguridad (security) en las organizaciones con un enfoque socio - criminológica . La premisa es que la seguridad es una necesidad humana básica , sino también una necesidad para la supervivencia de las empresas que operan en un mercado cada vez más global . La empresa es vista como una realidad social , un organismo micro - social en la interacción osmótica continua con el mundo exterior , de la que constantemente intercambios expectativas , la experiencia , la cultura , las experiencias de las personas que son actores sociales dentro y fuera de la empresa .
278

Messa alla prova e mediazione. Discrezionalità degli attori e pratiche di utilizzo / Probation and mediation: discretion of the Juvenile Justice System operators and concrete application

Carlone, Teresa <1987> January 1900 (has links)
Lo scopo della ricerca qui presentata è comprendere e tentare di spiegare, utilizzando due studi di caso, il Tribunali per i Minorenni dell’Emilia Romagna e del New Jersey, come la cultura della mediazione, e quella di riferimento del Restorative paradigm, possa essere legata alla discrezionalità soggettiva (favorevole o meno) degli operatori del sistema di giustizia minorile. In tale prospettiva, si cercherà di cogliere, all’interno del più ampio discorso sulla discrezionalità degli attori del processo penale minorile, l’importanza di fattori peculiari (quali la socializzazione lavorativa degli operatori, le prassi consolidate nei Tribunali e negli USSM, la collaborazione o mancata coordinazione tra gli attori stessi) negli orientamenti delle scelte di strumenti alternativi propri della restorative justice entro misure di intervento per giovani autori di reato. Trattandosi di un case study, non vi è alcuna pretesa di esaustività o generalizzabilità dei risultati ottenuti; essi, tuttavia, potrebbero rappresentare un significativo ed utile momento di riflessione dal quale (ri)partire per definire nuove procedure da attivare in questo ambito come, peraltro, da richiesta degli Organismi Comunitari, Europei e sovranazionali. A tal fine, si è scelto di individuare uno specifico istituto giuridico – peculiare del processo penale minorile – la messa alla prova (MAP) che, meglio di altri, permette la concreta applicazione di uno strumento della giustizia riparativa quale è la mediazione penale fra vittima e autore di reato. La comparazione con la realtà statunitense, nello specifico, mira ad arricchire l’analisi ponendo a confronto l’impiego di strumenti di giustizia riparativa – con particolare attenzione alle pratiche mediative – nei due contesti considerati. Il Nord America, patria natia dei programmi di diversion e della restorative justice, si configura come termine di paragone ideale per sviluppare una riflessione approfondita rispetto all’attenzione rivolta alle vittime e al consolidamento di una cultura della giustizia riparativa. / The aim of the research is to understand and attempt to explain, using the case study of Juvenile Courts in Emilia Romagna and New Jersey how the mediation culture could be shaped according to the personal discretion of the professional of the juvenile justice system. In this perspective, the research wants to demonstrate the importance, within the wider prospect of the high discretion of the Juvenile Justice System operators, that some specific factors (socialization in the work environment, well-established procedures in the Court and among the social services, collaboration or lack of cooperation of the workers) can contribute to the choice of alternative sanctions for juveniles. Using a case study approach doesn’t allow to gather quantitative data and obtain general results, but it will represent a significant and useful consideration from which we can (re)start to define new procedure in the field of Juvenile Justice, as required by the major European and International Organization [i.e.“Directive 2012/29/UE of the European Parliament and the Council, establishing minimum standards on the rights, support and protection of victims of crime, and replacing Council Framework Decision 2001/220/JHA]. The selection of one specific legal institution, probation, – related particularly to the Juvenile criminal procedure – seems to be the best choice in order to understand the concrete application of the mediation between the young author and his victim. The connection with the US aims to enrich the entire analysis and to make a comparison of the use of restorative justice instruments – focusing specifically on mediation – between the two Countries considered. The US is the birthplace of diversion programs and restorative paradigm, therefore it represents an important element of reflection regarding the attention of the system towards victims (their needs and feelings, for example) and the possible creation of a new restorative justice culture.
279

Al di là dell'etnopsichiatria. Georges Devereux tra scienza ed epistemologia / Beyond Ethnopsychiatry. Georges Devereux between science and epistemology

Cerea, Alessandra <1984> January 1900 (has links)
Questo lavoro verte sulla ricostruzione del pensiero dell’antropologo e psicoanalista Georges Devereux (1908-1985), attraverso un approccio storico-biografico e all’interno di una prospettiva che si discosta da quella tradizionale in cui Devereux è considerato il “padre dell’etnopsichiatria”. Intento principale della tesi è presentare un inedito Devereux epistemologo delle scienze dell’uomo, ricostruendo le tappe del suo percorso scientifico e rintracciando radici e storia dei principali concetti del suo sistema teorico nel contesto storico-culturale nonché nel quadro epistemologico in cui hanno preso forma. Le fonti principali di questa ricostruzione sono i materiali d’archivio del cospicuo Fondo Devereux, custodito all’Institut Mémoires de l’Édition Contemporaine (IMEC), nonché i dossier conservati all’École des Hautes Études en Sciences Sociales. Seguendo la ricerca di Devereux in fieri, attraverso le carte d’archivio, scritti inediti e scritti più o meno celebri, questo lavoro propone, in sostanza, di leggere dietro la nascita di questa “nuova scienza” (l’etnopsicoanalisi), il tentativo di fondare una nuova epistemologia e un nuovo metodo di osservazione per i saperi sull’uomo. Instaurando un dialogo tra fisica quantistica, antropologia e psicoanalisi – a partire dai concetti di complementarità e controtransfert – Devereux suggerisce, infatti, un nuovo approccio allo studio dell’uomo che, rifuggendo da riduzionismi o determinismi, sia il più possibile esaustivo e, prendendo in carico la soggettività del ricercatore, sia più efficace e realistico. La complessità e l’importanza del suo contributo teorico senza dubbio travalicano i confini dell’etnopsichiatria, perlomeno come oggi la intendiamo, e il percorso di Devereux, nella sua pluridisciplinarità e internazionalità, offre uno sguardo sul panorama intellettuale del ventesimo secolo che ha visto la nascita delle principali branche delle scienze umane, il loro sviluppo in tradizioni differenti, la progressiva specializzazione e frammentazione, ma anche tentativi, tenaci e difficili, di un dialogo. / This work focuses on the reconstruction of the thought of the anthropologist and psychoanalyst Georges Devereux (1908-1985), through a historical-biographical approach and within a perspective that differs from the traditional one according to which Devereux is considered the “father of Ethnopsychiatry”. The main aim of the thesis is to present an unprecedented Devereux “epistemologist of the human sciences”, by reconstructing the steps of his scientific path, the roots and the history of the main concepts of his theoretical system within both the historical-cultural context and the epistemological framework where they took shape. The main sources for this work are the archive material of the Devereux Fund, held by the Institut Mémoires de l’Édition Contemporaine (IMEC), and the dossiers held by the École des Hautes Études en Sciences Sociales. Following the Devereux’s research in fieri – through archive material, unpublished writings, famous works and less known ones – this work basically proposes to read, behind the origin of this “new science” (Ethnopsychoanalysis), the attempt to found a new epistemology and a new method of observation for human sciences. By establishing a dialogue between Quantum Physics, Anthropology and Psychoanalysis – starting from the concepts of complementarity and countertransference – Devereux suggests, indeed, a new approach for human studies which can be as comprehensive as possible, more effective and realistic. With no doubt, the complexity and the importance of his theoretical contribution go beyond the boundaries of Ethnopsychiatry, at least as we intend it today, and his multidisciplinary and international path offers an insight on the intellectual background of the 20th century, which witnessed the birth of the main branches of human sciences, their development in different traditions, their progressive specialization and fragmentation, but also constant and serious efforts for a dialogue
280

DELLA is O-Fucosylated by SPINDLY

Sui, Ning January 2016 (has links)
<p>Plant growth and development are strictly regulated by internal hormonal signaling networks, which integrate and coordinate to promote plants’ adaptation and survival in the changing environment. Among the diverse hormones, gibberellins (GAs) are the phytohormones that regulate various processes, from seed germination to fruit development. The conserved plant-specific GRAS family protein DELLAs, key repressors in the GA signaling pathway, serve as the central coordinator of multiple signaling networks through physical interactions with many key transcription factors/regulators in other pathways. </p><p>Diverse DELLA-interacting proteins (DIPs) from different signaling pathways and various protein families have been identified in recent years. All the DIPs interact with the C-terminal GRAS domain of DELLA, however, the mechanism of how the GRAS domain interacts with diverse proteins remains a mystery. To solve this problem, I expressed a number of DELLA proteins in E.coli and obtained high-purity protein for biochemical and structural analysis.</p><p>As the central coordinator of plant growth and development, DELLA’s activity and stability are regulated by post-translational modifications. Our lab recently showed that SECRET AGENT (SEC) modulates the activity of DELLA through O-linked N-acetylglucosamine (O-GlcNAc) modification in Arabidopsis. Nevertheless, SEC’s paralog SPINDLY (SPY), a putative O-GlcNAc transferase (OGT) identified 20 years ago, does not have OGT activity, and serves as opposite role to SEC in GA signaling with an unknown mechanism. </p><p>Our lab made the breakthrough in uncovering the SPY function, and showed it promotes the O-fucosylation of DELLA in planta. I further proved that SPY is a novel protein O-fucosyltransferase through biochemical analysis. SPY specifically transfers O-fucose from GDP-fucose to its substrate peptide, and SPY mutant proteins showed reduced or abolished transferase activity. This is the first work to identify O-fucosylation of nuclear proteins in any organism. O-fucosylation of DELLA activates DELLA by promoting its interaction with DIPs, opposite to repression of interaction with O-GlcNAcylation. Previous studies showed that SPY is involved in multiple cellular pathways such as GA signaling, cytokinin signaling and the circadian clock. Thus, SPY plays an important role in regulating plant growth and development through O-fucosylation of key components in diverse intracellular pathways. </p><p>SPY orthologs are conserved in bacteria, protists, algae and plants, while SEC orthologs are also present in fungi and animals. SPY-like and SEC-like proteins share high sequence similarity, except that two key residues important for the OGT activity of SEC is missing in SPY. Structure analysis of SPY (or its orthologs) would greatly facilitate our understanding of its unique substrate specificity. Toward this goal, I expressed Arabidopsis SPY proteins (as well as bacterial SPY orthologs) in E.coli and obtained high-purity protein for structural analysis. I further identified lead conditions that produce needle-cluster crystals. While optimization would be required, these studies will ultimately reveal the structure of SPY and the architecture of the active site, to show how SPY interacts with GDP-fucose for the transferase activity.</p> / Dissertation

Page generated in 0.0533 seconds