A Polarised Population of Dynamic Microtubules Mediates Homeostatic Length Control in Animal Cells

An analysis of cells grown on micro-patterned lines, and of cells during zebrafish development, identifies a population of microtubules that align along the long axis of cells to mediate homeostatic length control

Graphene Grown on Ni Foam: Molecular Sensing, Graphene-Enhanced Raman Scattering, and Galvanic Exchange for Surface-Enhanced Raman Scattering Applications

The growing of graphene on irregular 3D Ni structure demonstrates to be aninteresting platform for, molecular sensing, GERS, and SERS applications after galvanicexchange of Ag + ions. Raman, SEM (EDS), optical images, and diffuse reflectance exhibitthat graphene grows in multilayer (MLG) fashion with different stacking configurations.Statistics performed employing Raman show that as-grown graphene can be classified intwo main stacking configurations: AB (or Bernal stacking) and rotated graphene which areseparated by a 2D full-width half maximum (fwhm) threshold of ~30 cm -1 . Rotatedstacking senses low concentrations of methylene blue (MB) at 10 -6 M concentration,whereas AB-stacking seems to be much less sensitive upon molecular adsorption. Galvanicexchange of Ag leads to agglomerates preferentially formed on top graphene wrinkleswhich ultimately became target-spots for performing SERS. Our experiments demonstratethat as-grown graphene, comprised of different stacking configurations, can be used as amolecular sensor and detect nanomolar concentrations of MB and thiram (by SERSapplications), after galvanic exchange with Ag.Fil: Messina, María Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Picone, Andrea Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Dos Santos Claro, Paula Cecilia. YPF - Tecnología; ArgentinaFil: Ruiz, Remigio. YPF - Tecnología; ArgentinaFil: Saccone, Fabio Daniel. YPF - Tecnología; ArgentinaFil: Romano, Rosana Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Ibañez, Francisco Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

Graphene Grown on Ni Foam: Molecular Sensing, Graphene-Enhanced Raman Scattering, and Galvanic Exchange for Surface-Enhanced Raman Scattering Applications

The growing of graphene on irregular 3D Ni structure demonstrates to be aninteresting platform for, molecular sensing, GERS, and SERS applications after galvanicexchange of Ag + ions. Raman, SEM (EDS), optical images, and diffuse reflectance exhibitthat graphene grows in multilayer (MLG) fashion with different stacking configurations.Statistics performed employing Raman show that as-grown graphene can be classified intwo main stacking configurations: AB (or Bernal stacking) and rotated graphene which areseparated by a 2D full-width half maximum (fwhm) threshold of ~30 cm -1 . Rotatedstacking senses low concentrations of methylene blue (MB) at 10 -6 M concentration,whereas AB-stacking seems to be much less sensitive upon molecular adsorption. Galvanicexchange of Ag leads to agglomerates preferentially formed on top graphene wrinkleswhich ultimately became target-spots for performing SERS. Our experiments demonstratethat as-grown graphene, comprised of different stacking configurations, can be used as amolecular sensor and detect nanomolar concentrations of MB and thiram (by SERSapplications), after galvanic exchange with Ag.Centro de Química InorgánicaInstituto de Investigaciones Fisicoquímicas Teóricas y AplicadasConsejo Nacional de Investigaciones Científicas y Técnica

Asymmetric Mode of Ca2+-S100A4 Interaction with Nonmuscle Myosin IIA Generates Nanomolar Affinity Required for Filament Remodeling

Filament assembly of nonmuscle myosin IIA (NMIIA) is selectively regulated by the small Ca2+-binding protein, S100A4, which causes enhanced cell migration and metastasis in certain cancers. Our NMR structure shows that an S100A4 dimer binds to a single myosin heavy chain in an asymmetrical configuration. NMIIA in the complex forms a continuous helix that stretches across the surface of S100A4 and engages the Ca2+-dependent binding sites of each subunit in the dimer. Synergy between these sites leads to a very tight association (KD ∼1 nM) that is unique in the S100 family. Single-residue mutations that remove this synergy weaken binding and ameliorate the effects of S100A4 on NMIIA filament assembly and cell spreading in A431 human epithelial carcinoma cells. We propose a model for NMIIA filament disassembly by S100A4 in which initial binding to the unstructured NMIIA tail initiates unzipping of the coiled coil and disruption of filament packing

Oncogene-like induction of cellular invasion from centrosome amplification.

International audienceCentrosome amplification has long been recognized as a feature of human tumours; however, its role in tumorigenesis remains unclear. Centrosome amplification is poorly tolerated by non-transformed cells and, in the absence of selection, extra centrosomes are spontaneously lost. Thus, the high frequency of centrosome amplification, particularly in more aggressive tumours, raises the possibility that extra centrosomes could, in some contexts, confer advantageous characteristics that promote tumour progression. Using a three-dimensional model system and other approaches to culture human mammary epithelial cells, we find that centrosome amplification triggers cell invasion. This invasive behaviour is similar to that induced by overexpression of the breast cancer oncogene ERBB2 (ref. 4) and indeed enhances invasiveness triggered by ERBB2. Our data indicate that, through increased centrosomal microtubule nucleation, centrosome amplification increases Rac1 activity, which disrupts normal cell-cell adhesion and promotes invasion. These findings demonstrate that centrosome amplification, a structural alteration of the cytoskeleton, can promote features of malignant transformation