Galactocerebroside lipid nanotubes are membrane-mimicking systems for studying the function and structure of proteins involved in membrane shape remodeling, such as in intracellular trafficking, cell division, and migration or involved in the formation of membrane contact sites. They exhibit a constant and small diameter of 30 nm and a length of up to 2 μm. They can be functionalized with lipid ligands, providing a large binding surface for protein without membrane shape remodeling.
View Article and Find Full Text PDFThe human neocortex has undergone strong evolutionary expansion, largely due to an increased progenitor population, the basal radial glial cells. These cells are responsible for the production of a diversity of cell types, but the successive cell fate decisions taken by individual progenitors remain unknown. Here we developed a semi-automated live/fixed correlative imaging method to map basal radial glial cell division modes in early fetal tissue and cerebral organoids.
View Article and Find Full Text PDFPressure-induced transformations in an archetypal chalcogenide glass (GeSe) have been investigated up to 157 GPa by X-ray absorption spectroscopy (XAS) and molecular dynamics (MD) simulations. Ge and Se K-edge XAS data allowed simultaneous tracking of the correlated local structural and electronic changes at both Ge and Se sites. Thanks to the simultaneous analysis of extended X-ray absorption fine structure (EXAFS) signals of both edges, reliable quantitative information about the evolution of the first neighbor Ge-Se distribution could be obtained.
View Article and Find Full Text PDFContact (Thousand Oaks)
February 2024
Electron microscopy has played a pivotal role in elucidating the ultrastructure of membrane contact sites between cellular organelles. The advent of cryo-electron microscopy has ushered in the ability to determine atomic models of constituent proteins or protein complexes within sites of membrane contact through single particle analysis. Furthermore, it enables the visualization of the three-dimensional architecture of membrane contact sites, encompassing numerous copies of proteins, whether in vitro reconstituted or directly observed in situ using cryo-electron tomography.
View Article and Find Full Text PDFImprovement of electrochemical technologies is one of the most popular topics in the field of renewable energy. However, this process requires a deep understanding of the electrode-electrolyte interface behavior under conditions. X-ray absorption spectroscopy (XAS) is widely employed to characterize electrode materials, providing element-selective oxidation state and local structure.
View Article and Find Full Text PDFCells secrete extracellular vesicles (EVs) and non-vesicular extracellular (nano)particles (NVEPs or ENPs) that may play a role in intercellular communication. Tumor-derived EVs have been proposed to induce immune priming of antigen presenting cells or to be immuno-suppressive agents. We suspect that such disparate functions are due to variable compositions in EV subtypes and ENPs.
View Article and Find Full Text PDFTher Adv Musculoskelet Dis
November 2023
Osteoporosis and fragility fractures (FFs) are considered critical health problems by the World Health Organization (WHO) because of high morbidity, mortality, and healthcare costs. The occurrence of a FF raises the risk of a subsequent fracture (refracture). The hip is the most common site of fragility refracture, and its onset is associated with a further increase in patient's morbidity, mortality, and socioeconomic burden.
View Article and Find Full Text PDFMyosin VI (Myo6) is the only minus-end directed nanomotor on actin, allowing it to uniquely contribute to numerous cellular functions. As for other nanomotors, the proper functioning of Myo6 relies on precise spatiotemporal control of motor activity via a poorly defined off-state and interactions with partners. Our structural, functional, and cellular studies reveal key features of myosin regulation and indicate that not all partners can activate Myo6.
View Article and Find Full Text PDFThe time-integrated CP asymmetry in the Cabibbo-suppressed decay D^{0}→K^{-}K^{+} is measured using proton-proton collision data, corresponding to an integrated luminosity of 5.7 fb^{-1} collected at a center-of-mass energy of 13 TeV with the LHCb detector. The D^{0} mesons are required to originate from promptly produced D^{*+}→D^{0}π^{+} decays, and the charge of the companion pion is used to determine the flavor of the charm meson at production.
View Article and Find Full Text PDFAn amplitude analysis of the B^{+}→D_{s}^{+}D_{s}^{-}K^{+} decay is carried out to study for the first time its intermediate resonant contributions, using proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. A near-threshold peaking structure, referred to as X(3960), is observed in the D_{s}^{+}D_{s}^{-} invariant-mass spectrum with significance greater than 12 standard deviations. The mass, width, and the quantum numbers of the structure are measured to be 3956±5±10 MeV, 43±13±8 MeV, and J^{PC}=0^{++}, respectively, where the first uncertainties are statistical and the second systematic.
View Article and Find Full Text PDFHerein, we report the development of a new series of histone deacetylase inhibitors (HDACi) containing a 2-substituted 1,5-benzothiazepine scaffold. First, a virtual combinatorial library (∼1.6 × 10 items) was built according to a convenient synthetic route, and then it was submitted to molecular docking experiments on seven HDACs isoforms belonging to classes I and II.
View Article and Find Full Text PDFThe nuclear modification factor of neutral pions is measured in proton-lead collisions collected at a center-of-mass energy per nucleon of 8.16 TeV with the LHCb detector. The π^{0} production cross section is measured differentially in transverse momentum (p_{T}) for 1.
View Article and Find Full Text PDFA combined amplitude analysis is performed for the decays B^{0}→D[over ¯]^{0}D_{s}^{+}π^{-} and B^{+}→D^{-}D_{s}^{+}π^{+}, which are related by isospin symmetry. The analysis is based on data collected by the LHCb detector in proton-proton collisions at center-of-mass energies of 7, 8, and 13 TeV. The full data sample corresponds to an integrated luminosity of 9 fb^{-1}.
View Article and Find Full Text PDFHigh Energy Musculoskeletal Traumas (HEMTs) represent a relevant problem for healthcare systems, considering the high social costs, and both the high morbidity and mortality. The poor outcomes associated with HEMT are related to the high incidence of complications, including bone infection, fracture malunion and non-union. The treatment of each of these complications could be extremely difficult.
View Article and Find Full Text PDFSeptins are cytoskeletal proteins interacting with the inner plasma membrane and other cytoskeletal partners. Being key in membrane remodeling processes, they often localize at specific micrometric curvatures. To analyze the behavior of human septins at the membrane and decouple their role from other partners, we used a combination of bottom-up in vitro methods.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
May 2023
The protective coating of the electrode materials is a known source of improvement of the cycling performances in battery devices. In the case of the LiMnO cathodes, the coating with a thin alumina layer has been proven to show performance efficiency. However, the precise mechanism of its effect on the performance improvement of the electrodes is still not clear.
View Article and Find Full Text PDFPressure-induced transformations in glassy GeSehave been studied using the x-ray absorption spectroscopy. Experiments have been carried out at the scanning-energy beamline BM23 (European Synchrotron Radiation Facility) providing a micrometric x-ray focal spot up to pressures of about 45 GPa in a diamond anvil cell. Both Se and Ge K-edge experiments were performed under different hydrostatic conditions identifying the metallization onsets by accurate determinations of the edge shifts.
View Article and Find Full Text PDFMembrane contact sites (MCSs) are heterogeneous in shape, composition, and dynamics. Despite this diversity, VAP proteins act as receptors for multiple FFAT motif-containing proteins and drive the formation of most MCSs that involve the endoplasmic reticulum (ER). Although the VAP-FFAT interaction is well characterized, no model explains how VAP adapts to its partners in various MCSs.
View Article and Find Full Text PDFGalectin-3 (Gal3) is a β-galactoside binding lectin that mediates many physiological functions, including the binding of cells to the extracellular matrix for which the glycoprotein αβ integrin is of critical importance. The mechanisms by which Gal3 interacts with membranes have not been widely explored to date due to the complexity of cell membranes and the difficulty of integrin reconstitution within model membranes. Herein, to study their interaction, Gal3 and αβ were purified, and the latter reconstituted into pore-suspended lipid bilayers comprised eggPC:eggPA.
View Article and Find Full Text PDFThe fine regulation of actin polymerization is essential to control cell motility and architecture and to perform essential cellular functions. Formins are key regulators of actin filament assembly, known to processively elongate filament barbed ends and increase their polymerization rate. Different models have been extrapolated to describe the molecular mechanism governing the processive motion of formin FH2 domains at polymerizing barbed ends.
View Article and Find Full Text PDFBackground: Femoral neck fractures (FNF) are associated to patient's disability, reduced quality of life and mortality. None of the fixation devices commonly used for extracapsular (EC) FNF (i.e.
View Article and Find Full Text PDFIntracellular trafficking is mediated by transport carriers that originate by membrane remodeling from donor organelles. Tubular carriers contribute to the flux of membrane lipids and proteins to acceptor organelles, but how lipids and proteins impose a tubular geometry on the carriers is incompletely understood. Using imaging approaches on cells and in vitro membrane systems, we show that phosphatidylinositol-4-phosphate (PI4P) and biogenesis of lysosome-related organelles complex 1 (BLOC-1) govern the formation, stability, and functions of recycling endosomal tubules.
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