3 resultados para Stretch of The Imagination

em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain


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Amb una història que data de la dècada de 1950, la EUREGIO és un de les més antigues euroregions a Europa. Es pot considerar com un cas exitós d'una regió transfronterera (CBR) en el sentit que s'ha establert fermament com una agència de fronteres dins del seu tram de la frontera holandesa-alemanya. L'EUREGIO també ha estat una de les protagonistes principals darrere de l'Associació de Regions Frontereres Europees (ARFE), que en les últimes dècades va actuar per difondre el model d'euroregió a tot el territori europeu. Aquest capítol té diversos objectius. En primer lloc, es presenta el cas de la EUREGIO i presenta evidència sobre la seva història, estructura orgànica i polítiques. En segon lloc, s'analitzen les condicions del context en què la EUREGIO ha sorgit i les estructures de govern que es van crear com a resultat. Es fa especial èmfasi en la posició i el paper de l'Euroregió en el context més ampli del marc de governança europea multinivell generat per la política de cohesió de la UE. El capítol conclou amb un intent d'avaluar l'èxit i l'impacte de la EUREGIO i una discussió dels reptes relacionats amb la doble funció de l'EUREGIO com a representant dels interessos de les autoritats locals i les agències de cohesió de la UE posada en pràctica de les polítiques.

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The mechanical properties of the living cell are intimately related to cell signaling biology through cytoskeletal tension. The tension borne by the cytoskeleton (CSK) is in part generated internally by the actomyosin machinery and externally by stretch. Here we studied how cytoskeletal tension is modified during stretch and the tensional changes undergone by the sites of cell-matrix interaction. To this end we developed a novel technique to map cell-matrix stresses during application of stretch. We found that cell-matrix stresses increased with imposition of stretch but dropped below baseline levels on stretch release. Inhibition of the actomyosin machinery resulted in a larger relative increase in CSK tension with stretch and in a smaller drop in tension after stretch release. Cell-matrix stress maps showed that the loci of cell adhesion initially bearing greater stress also exhibited larger drops in traction forces after stretch removal. Our results suggest that stretch partially disrupts the actin-myosin apparatus and the cytoskeletal structures that support the largest CSK tension. These findings indicate that cells use the mechanical energy injected by stretch to rapidly reorganize their structure and redistribute tension.

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Nitrophorins represent a unique class of heme proteins that are able to perform the delicate transportation and release of the free-radical gaseous messenger nitric oxide (NO) in a pH-triggered manner. Besides its ability to bind to phospholipid membranes, the N-terminus contains an additional Leu-Pro-Gly stretch, which is a unique sequence trait, and the heme cavity is significantly altered with respect to other nitrophorins. These distinctive features encouraged us to solve the X-ray crystallographic structures of NP7 at low and high pH and bound with different heme ligands (nitric oxide, histamine, imidazole). The overall fold of the lipocalin motif is well preserved in the different X-ray structures and resembles the fold of other nitrophorins. However, a chain-like arrangement in the crystal lattice due to a number of head-to-tail electrostatic stabilizing interactions is found in NP7. Furthermore, the X-ray structures also reveal ligand-dependent changes in the orientation of the heme, as well as in specific interactions between the A-B and G-H loops, which are considered to be relevant for the biological function of nitrophorins. Fast and ultrafast laser triggered ligand rebinding experiments demonstrate the pH-dependent ligand migration within the cavities and the exit route. Finally, the topological distribution of pockets located around the heme as well as from inner cavities present at the rear of the protein provides a distinctive feature in NP7, so that while a loop gated exit mechanism to the solvent has been proposed for most nitrophorins, a more complex mechanism that involves several interconnected gas hosting cavities is proposed for NP7.