Search results for "FRAGMENTS"
showing 10 items of 422 documents
In vitro and in vivo arterial differentiation of human multipotent adult progenitor cells
2006
Many stem cell types have been shown to differentiate into endothelial cells (ECs); however, their specification to arterial or venous endothelium remains unexplored. We tested whether a specific arterial or venous EC fate could be induced in human multipotent adult progenitor cells (hMAPCs) and AC133(+) cells (hAC133(+)). In vitro, in the presence of VEGF(165), hAC133(+) cells only adopted a venous and microvascular EC phenotype, while hMAPCs differentiated into both arterial and venous ECs, possibly because hMAPCs expressed significantly more sonic hedgehog (Shh) and its receptors as well as Notch 1 and 3 receptors and some of their ligands. Accordingly, blocking either of those pathways …
Agonist and antagonist-dependent internalization of the human vasopressin V2 receptor.
1998
Abstract In this report we demonstrate that in HEK293 cells stably expressing the human V2vasopressin receptor, ligand-induced internalization of the hormone receptor occurs via the clathrin-dependent pathway. Studies of receptor trafficking either by direct visualization of the V2receptor by confocal microscopy or binding experiments show a rapid internalization (half-time 6–7 min). Blocking of the clathrin-dependent pathway by hypertonic sucrose increased vasopressin-induced cellular cAMP production and decreased the desensitization of the V2receptor–adenylyl cyclase system. Thus, internalization appears to be a major regulatory mechanism terminating vasopressin action in HEK293 cells. Tw…
Calcium-dependent conformational changes of membrane-bound Ebola fusion peptide drive vesicle fusion
2003
AbstractThe fusogenic subdomain of the Ebola virus envelope glycoprotein is an internal sequence located ca. 20 residues downstream the N-terminus of the glycoprotein transmembrane subunit. Partitioning of the Ebola fusion peptide into membranes containing phosphatidylinositol in the absence of Ca2+ stabilizes an α-helical conformation, and gives rise to vesicle efflux but not vesicle fusion. In the presence of millimolar Ca2+ the membrane-bound peptide adopts an extended β-structure, and induces inter-vesicle mixing of lipids. The peptide conformational polymorphism may be related to the flexibility of the virus–cell intermembrane fusogenic complex.
The Efficacy of Antigen Processing Is Critical for Protection against Cytomegalovirus Disease in the Presence of Viral Immune Evasion Proteins▿
2009
ABSTRACT Cytomegaloviruses (CMVs) code for immunoevasins, glycoproteins that are specifically dedicated to interfere with the presentation of antigenic peptides to CD8 T cells. Nonetheless, the biological outcome is not an immune evasion of the virus, since CD8 T cells can control CMV infection even when immunoevasins are expressed. Here, we compare the processing of a protective and a nonprotective epitope derived from the same viral protein, the antiapoptotic protein M45 in the murine model. The data provide evidence to conclude that protection against CMVs critically depends on antigenic peptides generated in an amount sufficient to exhaust the inhibitory capacity of immunoevasins.
La photographie ethnographique : la construction du fragment et de son écriture
2010
International audience
The deubiquitinase USP11 is a versatile and conserved regulator of autophagy
2021
Autophagy is a major cellular quality control system responsible for the degradation of proteins and organelles in response to stress and damage to maintain homeostasis. Ubiquitination of autophagy-related proteins or regulatory components is important for the precise control of autophagy pathways. Here, we show that the deubiquitinase ubiquitin-specific protease 11 (USP11) restricts autophagy and that KO of USP11 in mammalian cells results in elevated autophagic flux. We also demonstrate that depletion of the USP11 homolog H34C03.2 in Caenorhabditis elegans triggers hyperactivation of autophagy and protects the animals against human amyloid-β peptide 42 aggregation-induced paralysis. USP11…
Iron and zinc bioavailability in Caco-2 cells: Influence of caseinophosphopeptides
2013
Abstract A study has been made of the influence of two pools of caseinophosphopeptides (CPPs) obtained from α s - and β-casein (CN) fractions, and of three specific CPPs (β-CN(1–25)4P, α s1 -CN(64–74)4P and α s2 -CN(1–19)4P), on iron bioavailability (ferritin synthesis) and zinc bioavailability (retention, transport and uptake of zinc) in Caco-2 cells. α-CPP and β-CPP pools did not improve ferritin synthesis, but the three specific CPPs showed an increase in ferritin synthesis in Caco-2 cells versus iron sulphate, β-CN(1–25)4P being the most effective. In relation to zinc bioavailability, α-CPPs, β-CPPs, α s1 -CN(64–74)4P and β-CN(1–25)4P increased zinc uptake. However, this increase was of…
Force probe measurements of antibody-antigen interactions.
2000
The surface force apparatus has been used to quantify directly the forces that govern the interactions between proteins and ligands. In this work, we describe the measured interactions between the antigen fluorescein and the Fab' fragment of the monoclonal 4-4-20 anti-fluorescyl IgG antibody. Here we first describe the use of the surface force apparatus to demonstrate directly the impact of the charge composition in the region of the antibody binding site on the antibody interactions. Several approaches are described for immobilizing antigens, antibodies, and proteins in general for direct force measurements. The measured force profiles presented are accompanied by an extensive discussion o…
A High Sensitive Nested PCR for Toxoplasma gondii Detection in Animal and Food Samples
2013
Toxoplasma gondii is a major food and waterborne transmitted parasite world-wide. The tissues and meat samples of many warm blooded animals can contain tissues cysts from chronic toxoplasmosis. Water and vegetable can be contaminated by the parasitic oocysts shed through the feces of infected cats, representing the definitive host of the parasite. A sensitive PCR for Toxoplasma gondii detection is described. The first step amplified the region between the 28S and 18S rDNA in the closely related T. gondii and Neospora caninum; RFLP analysis distinguished the DNA from the two morphologically identical parasites. Although N. caninum is not involved in human transmission, so far, it is importan…
Anti-Human CD9 Fab Fragment Antibody Blocks the Extracellular Vesicle-Mediated Increase in Malignancy of Colon Cancer Cells.
2022
Intercellular communication between cancer cells themselves or with healthy cells in the tumor microenvironment and/or pre-metastatic sites plays an important role in cancer progression and metastasis. In addition to ligand–receptor signaling complexes, extracellular vesicles (EVs) are emerging as novel mediators of intercellular communication both in tissue homeostasis and in diseases such as cancer. EV-mediated transfer of molecular activities impacting morphological features and cell motility from highly metastatic SW620 cells to non-metastatic SW480 cells is a good in vitro example to illustrate the increased malignancy of colorectal cancer leading to its transformation and aggressive b…