Search results for "endosome"
showing 10 items of 104 documents
Early entry events in Echovirus 30 infection
2020
Echovirus 30 (E30), a member of the enterovirus B species, is a major cause of viral meningitis, targeting children and adults alike. While it is a frequently isolated enterovirus and the cause of several outbreaks all over the world, surprisingly little is known regarding its entry and replication strategy within cells. In this study, we used E30 strain Bastianni (E30B) generated from an infectious cDNA clone in order to study early entry events during infection in human RD cells. E30B required the newly discovered Fc echovirus receptor (FcRn) for successful infection, but not the coxsackievirus and adenovirus receptor (CAR) or decay-accelerating factor (DAF), although an interaction with …
Flotillin-involved uptake of silica nanoparticles and responses of an alveolar-capillary barrier in vitro
2013
AbstractDrug and gene delivery via nanoparticles across biological barriers such as the alveolar-capillary barrier of the lung constitutes an interesting and increasingly relevant field in nanomedicine. Nevertheless, potential hazardous effects of nanoparticles (NPs) as well as their cellular and systemic fate should be thoroughly examined. Hence, this study was designed to evaluate the effects of amorphous silica NPs (Sicastar) and (poly)organosiloxane NPs (AmOrSil) on the viability and the inflammatory response as well as on the cellular uptake mechanisms and fate in cells of the alveolar barrier. For this purpose, the alveolar epithelial cell line (NCI H441) and microvascular endothelial…
Unjamming overcomes kinetic and proliferation arrest in terminally differentiated cells and promotes collective motility of carcinoma.
2019
During wound repair, branching morphogenesis and carcinoma dissemination, cellular rearrangements are fostered by a solid-to-liquid transition, known as unjamming. The biomolecular machinery behind unjamming and its pathophysiological relevance remain, however, unclear. Here, we study unjamming in a variety of normal and tumorigenic epithelial two-dimensional (2D) and 3D collectives. Biologically, the increased level of the small GTPase RAB5A sparks unjamming by promoting non-clathrin-dependent internalization of epidermal growth factor receptor that leads to hyperactivation of the kinase ERK1/2 and phosphorylation of the actin nucleator WAVE2. This cascade triggers collective motility effe…
Subcellular fractionation of tissue culture cells.
2003
Cell fractionation techniques include some of the most important and widely used analytical tools in cell and molecular biology, and are essential for the development of cell-free assays that reconstitute complicated cellular processes. In addition to simple gradient systems, this unit discusses the immuno-purification of organelles, in particular endosomes. As antigens, purification can be achieved using endogenous or ectopically expressed proteins, provided that appropriate antibodies are available. Alternatively, tagged proteins can be used, when combined with anti-tag antibodies. Now that sequencing of the genomes of several organisms has been completed, biochemical strategies, and in p…
Calpains promote α2β1 integrin turnover in nonrecycling integrin pathway
2012
A novel virus- and integrin clustering–specific pathway diverts integrin from its normal endo/exocytic traffic to a nonrecycling degradative endosomal route. Clustering of α2β1 integrin causes redistribution of the integrin to perinuclear endosomes, leading to enhanced integrin turnover promoted by calpains.
Membrane-bound exosomal HSP70 as a biomarker for detection and monitoring of malignant solid tumours: a pilot study
2019
Abstract Background Cancer is the second leading cause of death globally. Early detection and disease management lead to a better survival rate. Consequently, discovery of novel methods in cancer early diagnosis is a field of active research. Minimally invasive liquid biopsies are generating growing interest. Circulating tumour cells (CTCs) have been identified in patients’ blood; nevertheless, these cells are rare and heterogeneous. Exosomes are extracellular nanovesicles released into the extracellular environment via the endosomal vesicle pathway and found in different body fluids. Exosomes deliver bioactive cargo such as proteins, mRNA and miRNA to recipient cells in the tumour environm…
Improvement in Nuclear Entry and Transgene Expression of Baculoviruses by Disintegration of Microtubules in Human Hepatocytes
2005
ABSTRACT Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV), a potent virus for mammalian cell gene delivery, possesses an ability to transduce mammalian cells without viral replication. We examined the role of the cellular cytoskeleton in the cytoplasmic trafficking of viral particles toward the nucleus in human hepatic cells. Microscopic studies showed that capsids were found in the nucleus after either viral inoculation or cytoplasmic microinjection of nucleocapsids. The presence of microtubule (MT) depolymerizing agents caused the amount of nuclear capsids to increase. Overexpression of p50/dynamitin, an inhibitor of dynein-dependent endocytic trafficking from peripheral e…
γ2-Adaptin, a Ubiquitin-interacting Adaptor, Is a Substrate to Coupled Ubiquitination by the Ubiquitin Ligase Nedd4 and Functions in the Endosomal Pa…
2008
gamma2-Adaptin is a putative member of the clathrin adaptor protein family with unknown physiological function. We previously reported that gamma2-adaptin acts as a ubiquitin receptor by virtue of its ubiquitin-interacting motif. Here we demonstrate that this motif mediates a specific physical interaction with the ubiquitin ligase Nedd4 and promotes ubiquitination of gamma2-adaptin. By mapping regions of Nedd4 involved in binding to gamma2-adaptin, we identified its C2 domain to be essential, whereas the WW and HECT domains are dispensable. Consistent with this, we uncovered that the C2 domain of Nedd4 is ubiquitinated itself and as such is recruited by the ubiquitin-interacting motif of ga…
Extracellular vesicles shuffling intercellular messages: for good or for bad
2015
The release of extracellular vesicles (EVs) is a highly conserved process exploited by diverse organisms as a mode of intercellular communication. Vesicles of sizes ranging from 30 to 1000. nm, or even larger, are generated by blebbing of the plasma membrane (microvesicles) or formed in multivesicular endosomes (MVEs) to be secreted by exocytosis as exosomes. Exosomes, microvesicles and other EVs contain membrane and cytosolic components that include proteins, lipids and RNAs, a composition that differs related to their site of biogenesis. Several mechanisms are involved in vesicle formation at the plasma membrane or in endosomes, which is reflected in their heterogeneity, size and composit…
γ2-Adaptin is functioning in the late endosomal sorting pathway and interacts with ESCRT-I and -III subunits.
2010
Abstractγ2-Adaptin is a clathrin adaptor-related protein with unclear physiological function. Previous studies indicated that γ2-adaptin might act within the multivesicular body (MVB) protein-sorting pathway that is central to receptor down-regulation, lysosome biogenesis, and budding of enveloped viruses. Here, we have analyzed the effects of excess and deficit γ2-adaptin on exogenous and endogenous MVB cargoes and on the MVB machinery itself. Foreign cargoes, like retroviral Gags, are entrapped by overexpressed γ2-adaptin in detergent-insoluble polymers and blocked in budding. When viral budding involves MVB/endosomal structures, excess γ2-adaptin acts by accelerating lysosomal Gag destru…