Ras–GAP SH3 domain binding protein (G3BP) is a modulator of USP10, a novel human ubiquitin specific protease

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Removal of C-terminal Src kinase from the immune synapse by a new binding protein

The Csk tyrosine kinase negatively regulates the Src family kinases Lck and Fyn in T cells. Engagement of the T cell antigen receptor results in a removal of Csk from the lipid raft-associated transmembrane protein PAG/Cbp. Instead, Csk becomes associated with a ∼72-kDa tyrosine phosphorylated protein, which we here identify as G3BP, a phosphoprotein reported to bind the SH3 domain of Ras GTPase activating protein. G3BP reduced the ability of Csk to phosphorylate Lck at Y505 by decreasing the amount of Csk in lipid rafts. As a consequence, G3BP augmented T cell activation as measured by IL-2 gene activation. Conversely, elimination of endogenous G3BP by RNA interference reduced TCR signaling. In antigen-specific T cells, endogenous G3BP moved into a intracellular location adjacent to the immune synapse, but well inside the cell, upon antigen recognition. Csk co-localization with G3BP occurred in this ‘parasynaptic’ location. We conclude that G3BP is a new player in TCR signaling that acts to reduce the amount of Csk in the immune synapse

EIF2A-dependent translational arrest protects leukemia cells from the energetic stress induced by NAMPT inhibition

Cell-cycle analysis andClick-iTdetection of RNA and Protein synthesis. A) Cell-cycle analysis with PI staining of the nuclei after 48 h of treatment. Overnight serum starvation is shown as a positive control of induced cell cycle synchronization in G0/G1 phase. Cell phase analysis was done with ModFit LT 3.2 software by using the Sync Wizard model (30000 cells/sample in biological duplicate). B) Jurkat cells were treated for 48 h with or without (Mock) the indicated concentration of FK866 or for 3 h with 5 μM Actinomycin D, an RNA synthesis blocking agent, then subjected to Click-it biochemistry and flow-cytometry analyses including 7-AAD to identify living cells. C) Jurkat cells were treated for 48 h with or without (Mock) the indicated concentration of FK866 or for 3 h with 350 μM Cycloheximide, as a positive control for protein synthesis inhibition, then stained as in B. In B and C. Experiments were carried out on two biological replicates (50000 events/sample). (PDF 1562 kb

Removal of C-Terminal Src Kinase from the Immune Synapse by a New Binding Protein

The Csk tyrosine kinase negatively regulates the Src family kinases Lck and Fyn in T cells. Engagement of the T-cell antigen receptor results in a removal of Csk from the lipid raft-associated transmembrane protein PAG/Cbp. Instead, Csk becomes associated with an ∼72-kDa tyrosine-phosphorylated protein, which we identify here as G3BP, a phosphoprotein reported to bind the SH3 domain of Ras GTPase-activating protein. G3BP reduced the ability of Csk to phosphorylate Lck at Y505 by decreasing the amount of Csk in lipid rafts. As a consequence, G3BP augmented T-cell activation as measured by interleukin-2 gene activation. Conversely, elimination of endogenous G3BP by RNA interference increased Lck Y505 phosphorylation and reduced TCR signaling. In antigen-specific T cells, endogenous G3BP moved into a intracellular location adjacent to the immune synapse, but deeper inside the cell, upon antigen recognition. Csk colocalization with G3BP occurred in this “parasynaptic” location. We conclude that G3BP is a new player in T-cell-antigen receptor signaling and acts to reduce the amount of Csk in the immune synapse

Integrating Landsat and Sentinel-2 time series for enhancing the estimation of soil erosion in the Alps

Soil erosion is a naturally dynamic phenomenon, but human activities, human-induced forces and climate change have further accelerated this process. As a consequence, the mean annual soil loss rate in Europe exceeds the average soil formation rate. That means soil can be actually considered as a non-renewable resource. Therefore, understanding spatial patterns and temporal trends of soil loss could support government land use policies and strategies for reducing this overlooked natural hazard. Among the factors driving soil erosion dynamics, meteorological forcings and land cover/land use vary in time and space, while other factors like soil properties (i.e. their pedology) and topography can be considered constant over time. Soil erosion can be reduced acting on land cover/land use, but, this factor is the most complex and expensive to be continuatively monitored by national or regional agencies through field campaign or ad hoc surveys. However, satellites for Earth Observation can help a lot in monitoring spatial and temporal land cover changes and the cover management factor can be effectively estimated through spectral indices (e.g. NDVI). This paper describes an ad hoc implementation of the Revised Universal Soil Loss Equation (RUSLE) model to provide dynamic maps of soil erosion. In this work, we evaluate the benefits of integrating Landsat and Sentinel-2 time series to study soil erosion in an alpine river basin of Italy. Thus, reducing the revisit time up to 5 days allows to consider the effects on soil erosion of land use/land cover modification caused by extreme meteorological events, that otherwise would be missed if estimating soil erosion through institutional product of land use/land cover. Besides, the high revisit time provided by the combination of the two sensors could provide snow cover maps of the study area, useful for quantifying the contribution to erosion of soil covered by snow. Results demonstrate that the ESA’ Sentinel-2 twin satellites could effectively enhance the estimate of the cover management factor, both spatially and temporally

Relire La Légende d'Ulenspiegel

La Légende d’Ulenspiegel, de Charles De Coster, est souvent vue comme le texte fondateur de la littérature belge. Quelque mythique que soit ce jugement, cette Légende est peu à peu devenue le pivot de l’historiographie des lettres belges, qui n’a cessé de l’interroger pour en montrer la complexité foisonnante. C’est aussi un texte qui a constamment inspiré les créateurs de tous horizons. La Légende a en effet engendré son lot d’adaptations – théâtre, film, bande dessinée, réécriture pour enfants, opéra… – mais aussi inspiré maintes œuvres originales. Dans ces textes, on constate souvent le retour d’éléments emprunté à l’Uilenspiegel traditionnel, mariés avec des éléments proprement costériens. Ces continuations et ces adaptations ont largemement ouvert l’éventail des interprétations de l’œuvre. C’est à l’univers des continuateurs, des relecteurs et des transmetteurs du grand texte de De Coster que la revue Textyles consacre le numéro qu’elle publie à l’occasion du cent-cinquantième anniversaire de la publication de l’Ulenspiegel

3D photopolymerized microstructured scaffolds influence nuclear deformation, nucleo/cytoskeletal protein organization, and gene regulation in mesenchymal stem cells

Mechanical stimuli from the extracellular environment affect cell morphology and functionality. Recently, we reported that mesenchymal stem cells (MSCs) grown in a custom-made 3D microscaffold, the Nichoid, are able to express higher levels of stemness markers. In fact, the Nichoid is an interesting device for autologous MSC expansion in clinical translation and would appear to regulate gene activity by altering intracellular force transmission. To corroborate this hypothesis, we investigated mechanotransduction-related nuclear mechanisms, and we also treated spread cells with a drug that destroys the actin cytoskeleton. We observed a roundish nuclear shape in MSCs cultured in the Nichoid and correlated the nuclear curvature with the import of transcription factors. We observed a more homogeneous euchromatin distribution in cells cultured in the Nichoid with respect to the Flat sample, corresponding to a standard glass coverslip. These results suggest a different gene regulation, which we confirmed by an RNA-seq analysis that revealed the dysregulation of 1843 genes. We also observed a low structured lamina mesh, which, according to the implemented molecular dynamic simulations, indicates reduced damping activity, thus supporting the hypothesis of low intracellular force transmission. Also, our investigations regarding lamin expression and spatial organization support the hypothesis that the gene dysregulation induced by the Nichoid is mainly related to a reduction in force transmission. In conclusion, our findings revealing the Nichoid's effects on MSC behavior is a step forward in the control of stem cells via mechanical manipulation, thus paving the way to new strategies for MSC translation to clinical applications

APO866 Increases Antitumor Activity of Cyclosporin-A by Inducing Mitochondrial and Endoplasmic Reticulum Stress in Leukemia Cells

The nicotinamide phosphoribosyltransferase (NAMPT) inhibitor, APO866, has been previously shown to have antileukemic activity in preclinical models, but its cytotoxicity in primary leukemia cells is frequently limited. The success of current antileukemic treatments is reduced by the occurrence of multidrug resistance, which, in turn, is mediated by membrane transport proteins, such as P-glycoprotein-1 (Pgp). Here, we evaluated the antileukemic effects of APO866 in combination with Pgp inhibitors and studied the mechanisms underlying the interaction between these two types of agents