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Gheorghe Cojoc Emanuele Roscioli Lijuan Zhang Alfonso García-Ulloa Jagesh V. Shah Michael W. Berns Nenad Pavin Daniela Cimini Iva M. Toli? Juraj Gregan 《The Journal of cell biology》2016,212(7):767-776
Accurate chromosome segregation depends on proper kinetochore–microtubule attachment. Upon microtubule interaction, kinetochores are subjected to forces generated by the microtubules. In this work, we used laser ablation to sever microtubules attached to a merotelic kinetochore, which is laterally stretched by opposing pulling forces exerted by microtubules, and inferred the mechanical response of the kinetochore from its length change. In both mammalian PtK1 cells and in the fission yeast Schizosaccharomyces pombe, kinetochores shortened after microtubule severing. Interestingly, the inner kinetochore–centromere relaxed faster than the outer kinetochore. Whereas in fission yeast all kinetochores relaxed to a similar length, in PtK1 cells the more stretched kinetochores remained more stretched. Simple models suggest that these differences arise because the mechanical structure of the mammalian kinetochore is more complex. Our study establishes merotelic kinetochores as an experimental model for studying the mechanical response of the kinetochore in live cells and reveals a viscoelastic behavior of the kinetochore that is conserved in yeast and mammalian cells. 相似文献
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Nunzio Vicario Federica M. Spitale Daniele Tibullo Cesarina Giallongo Angela M. Amorini Grazia Scandura Graziana Spoto Miriam W. Saab Simona DAprile Cristiana Alberghina Renata Mangione Joshua D. Bernstock Cirino Botta Massimo Gulisano Emanuele Buratti Giampiero Leanza Robert Zorec Michele Vecchio Michelino Di Rosa Giovanni Li Volti Giuseppe Lazzarino Rosalba Parenti Rosario Gulino 《Cell death & disease》2021,12(7)
Motoneuronal loss is the main feature of amyotrophic lateral sclerosis, although pathogenesis is extremely complex involving both neural and muscle cells. In order to translationally engage the sonic hedgehog pathway, which is a promising target for neural regeneration, recent studies have reported on the neuroprotective effects of clobetasol, an FDA-approved glucocorticoid, able to activate this pathway via smoothened. Herein we sought to examine functional, cellular, and metabolic effects of clobetasol in a neurotoxic mouse model of spinal motoneuronal loss. We found that clobetasol reduces muscle denervation and motor impairments in part by restoring sonic hedgehog signaling and supporting spinal plasticity. These effects were coupled with reduced pro-inflammatory microglia and reactive astrogliosis, reduced muscle atrophy, and support of mitochondrial integrity and metabolism. Our results suggest that clobetasol stimulates a series of compensatory processes and therefore represents a translational approach for intractable denervating and neurodegenerative disorders.Subject terms: Biochemistry, Diseases of the nervous system, Glial biology, Physiology 相似文献
848.
David Pantoja-Uceda Cristiana Stuani Douglas V. Laurents Ann E. McDermott Emanuele Buratti Miguel Mompen 《PLoS biology》2021,19(4)
Transactive response DNA-binding Protein of 43 kDa (TDP-43) assembles various aggregate forms, including biomolecular condensates or functional and pathological amyloids, with roles in disparate scenarios (e.g., muscle regeneration versus neurodegeneration). The link between condensates and fibrils remains unclear, just as the factors controlling conformational transitions within these aggregate species: Salt- or RNA-induced droplets may evolve into fibrils or remain in the droplet form, suggesting distinct end point species of different aggregation pathways. Using microscopy and NMR methods, we unexpectedly observed in vitro droplet formation in the absence of salts or RNAs and provided visual evidence for fibrillization at the droplet surface/solvent interface but not the droplet interior. Our NMR analyses unambiguously uncovered a distinct amyloid conformation in which Phe-Gly motifs are key elements of the reconstituted fibril form, suggesting a pivotal role for these residues in creating the fibril core. This contrasts the minor participation of Phe-Gly motifs in initiation of the droplet form. Our results point to an intrinsic (i.e., non-induced) aggregation pathway that may exist over a broad range of conditions and illustrate structural features that distinguishes between aggregate forms.The prion-like domain of TDP-43 assembles biomolecular condensates which mature into amyloid fibrils that accumulate at the condensate/solvent interface. In vitro reconstitution of these fibrils reveals an amyloid core stabilized by residues that are not necessarily essential to create the droplet form. 相似文献
849.
Phenological models are important tools for planning viticultural practices in the short term and for projecting the impact
of climate change on grapevine (Vitis vinifera) in the long term. However, the difficulties in obtaining phenological models which provide accurate predictions on a regional
scale prevent them from being exploited to their full potential. The aim of this work was to obtain a robust phenological
model for V. vinifera cv. Chardonnay. During calibration of the sub-models for budburst, flowering and veraison we implemented a series of measures
to prevent overfitting and to give greater physiological meaning to the models. Among these were the use of experimental information
on the response of Chardonnay to forcing temperatures, restriction of parameter space into physiologically meaningful limits
prior to calibration, and simplification of the previously selected sub-models. The resulting process-based model had good
internal validity and a good level of accuracy in predicting phenological events from external datasets. Model performance
was especially high for the prediction of flowering and veraison, and comparison with other models confirmed it as a better
predictor of phenology, even in extremely warm years. The modelling study highlighted a different phenological behaviour at
the only mountain station, Cembra. We hypothesised that phenotypical plasticity could lead to growth rates adapting to a lower
mean temperature, a mechanism not usually accounted for by phenological models. 相似文献
850.
Vincenza Calabrò Emanuele Ricca Maria Gabriela De Paola Stefano Curcio Gabriele Iorio 《Bioprocess and biosystems engineering》2010,33(6):701-710
In this paper, the reaction of enzymatic trans-esterification of glycerides with ethanol in a reaction medium containing hexane
at a temperature of 37 °C has been studied. The enzyme was Lipase from Mucor miehei, immobilized on ionic exchange resin, aimed at achieving high catalytic specific surface and recovering, regenerating and
reusing the biocatalyst. A kinetic analysis has been carried out to identify the reaction path; the rate equation and kinetic
parameters have been also calculated. The kinetic model has been validated by comparison between predicted and experimental
results. Mass transport resistances estimation was undertaken in order to verify that the kinetics found was intrinsic. Model
potentialities in terms of reactors design and optimization are also shown. 相似文献