114 research outputs found
Il tempo della 'Wiederkehr': macro e micro-forma di un rondò coreografico di Aurel Milloss e Roman Vlad
No full textL’Uomo e la sua lotta col destino costituiscono il fulcro drammaturgico di 'Die Wiederkehr', un balletto di Aurel Milloss su musica di Roman Vlad rappresentato per la prima volta alla Kölner Opernhaus nel 1962. Questo «choreographischer rondò in Elf tänze», infatti, mette in scena – attraverso degli incontri allucinati, in un luogo indeterminato e in un tempo sospeso – la ricerca dell’uomo della propria individualità. Nel riprendere questa tematica cara al teatro espressionista, il coreografo rinuncia alla linearità della narrazione per concentrarsi sulla costruzione di un «Ideenballett», il cui tempo e il ritmo interni sono fatti di continui ritorni. La coerenza di 'Die Wiederkehr' sta dunque nell’intricata rete di simmetrie che Milloss ha immaginato – e fissato per iscritto – per musica e danza. A partire proprio dagli appunti milossiani e dal loro confronto con gli schizzi di Vlad, verrà proposta un’analisi dell’architettura formale del balletto, al fine di evidenziare come sia stata costruita la temporalità della 'Wiederkehr'
Lipid-transfer proteins in membrane trafficking at the Golgi complex
No full textThe Golgi complex (GC) represents the central junction for membrane trafficking. Protein and lipid cargoes continuously move through the GC in both anterograde and retrograde directions, departing to and arriving from diverse destinations within the cell. Nevertheless, the GC is able to maintain its identity and strict compartmentalisation, having a different composition in terms of protein and lipid content compared to other organelles. The discovery of coat protein complexes and the elucidation of their role in sorting cargo proteins into specific transport carriers have provided a partial answer to this phenomenon. However, it is more difficult to understand how relatively small and diffusible molecules like lipids can be concentrated in or excluded from specific subcellular compartments. The discovery of lipid-transfer proteins operating in the secretory pathway and specifically at the GC has shed light on one possible way in which this lipid compartmentalisation can be accomplished. The correct lipid distribution along the secretory pathway is of crucial importance for cargo protein sorting and secretion. This review focuses on what is now known about the putative and effective lipid-transfer proteins at the GC, and on how they affect the function and structure of the GC itself
Shakespeare e Napoli: prove di infedeltà. Considerazioni su attori, capocomici e traduttori tra Otto e Novecento
No full textLarge pleiomorphic traffic intermediates in the secretory pathway
No full textThere are two main classes of traffic intermediates that operate in intracellular trafficking pathways: small round vesicles, and large pleiomorphic carriers (LPCs). While both are essential, the LPCs appear to be responsible for moving the bulk of the secretory traffic between distant compartments. LPCs are much larger and more variable in shape than vesicles, and they have evident interconnected tubular and saccular/cisternal components. They appear to form by en bloc extrusion and cleavage of large membrane areas of the donor organelle. Although many proteins and lipids that are involved in LPC formation have been identified, the intrinsic complexity of these carriers and current technical limitations mean that a coherent picture of the process of of LPC formation is only just beginning to emerge
Mutational analysis of the yeast TRAPP subunit Trs20p identifies roles in endocytic recycling and sporulation
No full textTrs20p is a subunit of the evolutionarily conserved TRAPP (TRAnsport Protein Particle) complex that mediates various aspects of membrane trafficking. Three TRAPP complexes have been identified in yeast with roles in ER-to-Golgi trafficking, post-Golgi and endosomal-to-Golgi transport and in autophagy. The role of Trs20p, which is essential for viability and a component of all three complexes, and how it might function within each TRAPP complex, has not been clarified to date. To begin to address the role of Trs20p we generated different mutants by random mutagenesis but, surprisingly, no defects were observed in diverse anterograde transport pathways or general secretion in Trs20 temperature-sensitive mutants. Instead, mutation of Trs20 led to defects in endocytic recycling and a block in sporulation/meiosis. The phenotypes of different mutants appear to be separable suggesting that the mutations affect the function of Trs20 in different TRAPP complexes
Function and dysfunction of the PI system in membrane trafficking
No full textThe phosphoinositides (PIs) function as efficient and finely tuned switches that control the assembly-disassembly cycles of complex molecular machineries with key roles in membrane trafficking. This important role of the PIs is mainly due to their versatile nature, which is in turn determined by their fast metabolic interconversions. PIs can be tightly regulated both spatially and temporally through the many PI kinases (PIKs) and phosphatases that are distributed throughout the different intracellular compartments. In spite of the enormous progress made in the past 20 years towards the definition of the molecular details of PI-protein interactions and of the regulatory mechanisms of the individual PIKs and phosphatases, important issues concerning the general principles of the organisation of the PI system and the coordination of the different PI-metabolising enzymes remain to be addressed. The answers should come from applying a systems biology approach to the study of the PI system, through the integration of analyses of the protein interaction data of the PI enzymes and the PI targets with those of the 'phenomes' of the genetic diseases that involve these PI-metabolising enzymes
An osmotic computing infrastructure for urban pollution monitoring
No full textUrban pollution control systems suffer from the presence of fixed stations in a greater number than mobile monitoring devices. Data gathered from such stations provide detailed and reliable information, thanks to equipment quality and effective measuring protocols, but these sampled data are gathered from very limited areas and through discontinuous monitoring campaigns. Fortunately, the spread of technologies for mobility has fostered the development of new approaches like mobile crowdsensing (MCS), increasing the chances of using mobile devices, even personal ones, as suitable sensors for the urban monitoring scenario. Nevertheless, one of the open challenges is the management of integrated heterogeneous data flows, differing in terms of typology, technical specifications (eg, transmission protocols), and semantics. The osmotic computing paradigm aims at creating an abstract level between mobile devices/Internet-of-Things devices and a cloud platform, which enables opportunistic filtering and the addition of metadata for improving the data processing flow. This work focuses on the design and development of a middleware that integrates data coming from mobile and Internet-of-Things devices specifically deployed in urban contexts using the osmotic computing paradigm. Moreover, a component of the osmotic membrane has been developed for security management
The multiple roles of PtdIns(4)P - Not just the precursor of PtdIns(4,5)P2
No full textThe phosphoinositides (PIs) are membrane phospholipids that actively operate at membrane-cytosol interfaces through the recruitment of a number of effector proteins. In this context, each of the seven different PI species represents a topological determinant that can establish the nature and the function of the membrane where it is located. Phosphatidylinositol 4-phosphate (PtdIns(4)P) is the most abundant of the monophosphorylated inositol phospholipids in mammalian cells, and it is produced by D-4 phosphorylation of the inositol ring of PtdIns. PtdIns(4)P can be further phosphorylated to PtdIns(4,5)P(2) by PtdIns(4)P 5-kinases and, indeed, PtdIns(4)P has for many years been considered to be just the precursor of PtdIns(4,5)P(2). Over the last decade, however, a large body of evidence has accumulated that shows that PtdIns(4)P is, in its own right, a direct regulator of important cell functions. The subcellular localisation of the PtdIns(4)P effectors initially led to the assumption that the bulk of this lipid is present in the membranes of the Golgi complex. However, the existence and physiological relevance of ;non-Golgi pools' of PtdIns(4)P have now begun to be addressed. The aim of this Commentary is to describe our present knowledge of PtdIns(4)P metabolism and the molecular machineries that are directly regulated by PtdIns(4)P within and outside of the Golgi complex
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