A5101442484- Cellular transport and secretion
- Cellular Mechanics and Interactions
- Bacillus and Francisella bacterial research
- Lipid Membrane Structure and Behavior
- Monoclonal and Polyclonal Antibodies Research
- Advanced Fluorescence Microscopy Techniques
- Calcium signaling and nucleotide metabolism
- Advanced Electron Microscopy Techniques and Applications
- Lysosomal Storage Disorders Research
- Yersinia bacterium, plague, ectoparasites research
- Galectins and Cancer Biology
- Mycobacterium research and diagnosis
- Photosynthetic Processes and Mechanisms
- Vector-borne infectious diseases
- ATP Synthase and ATPases Research
- Mosquito-borne diseases and control
- Microtubule and mitosis dynamics
- Mitochondrial Function and Pathology
- Cell Adhesion Molecules Research
- Viral Infections and Outbreaks Research
- MicroRNA in disease regulation
- Extracellular vesicles in disease
- Caveolin-1 and cellular processes
- Legionella and Acanthamoeba research
- Metal complexes synthesis and properties
University of Oslo
2009-2022
Institut de Myologie
2012
Centre de Recherche en Myologie
2012
Sorbonne Université
2012
Defence Science and Technology Laboratory
2001-2011
European Molecular Biology Organization
1997-2008
European Molecular Biology Laboratory
1994-2000
European Molecular Biology Laboratory
1989-2000
Virginia Tech
1991
University of Wales
1990
The organization of the endosome compartment in BHK-21 cells was studied by using horseradish peroxidase as a fluid-phase marker and Semliki Forest virus an adsorptive marker. Stereo pairs semithin sections (0.2-0.5 micron) computer-aided reconstruction tracing serial thin (CARTOS) were used to obtain three-dimensional images labeled compartments. Two types organelles could be observed: small vesicles tubules (approximately equal 50 nm diameter) large complex structures consisting central...
Egress of malaria parasites from the host cell requires concerted rupture its enveloping membranes. Hence, we investigated role plasmodial perforin-like protein PPLP2 in egress Plasmodium falciparum erythrocytes. is expressed blood stage schizonts and mature gametocytes. The localizes vesicular structures, which activated gametocytes discharge a calcium-dependent manner. comprises MACPF domain recombinant has haemolytic activities towards PPLP2-deficient [PPLP2(−)] merozoites show normal...
The causative agent of Legionnaires' disease, Legionella pneumophila, uses the Icm/Dot type IV secretion system (T4SS) to form in phagocytes a distinct "Legionella-containing vacuole" (LCV), which intercepts endosomal and secretory vesicle trafficking. Proteomics revealed presence small GTPase Ran its effector RanBP1 on purified LCVs. Here we validate that localize LCVs promote intracellular growth L. pneumophila. Moreover, pneumophila protein LegG1, contains putative RCC1 guanine nucleotide...
L-leucyl-L-leucine methyl ester (LLOMe) induces apoptosis, which is thought to be mediated by release of lysosomal cysteine cathepsins from permeabilized lysosomes into the cytosol. Here, we demonstrated in HeLa cells that apoptotic as well sub-apoptotic concentrations LLOMe caused rapid and complete membrane permeabilization (LMP), evidenced loss proton gradient cytosol internalized markers below a relative molecular mass 10,000. However, there was no evidence for B L cytosol; rather they...
The vacuolar H(+)-ATPase (v-ATPase) complex is instrumental in establishing and maintaining acidification of some cellular compartments, thereby ensuring their functionality. Recently it has been proposed that the transmembrane V0 sector v-ATPase its a-subunits promote membrane fusion endocytic exocytic pathways independent functions. Here, we tested if such a proton-pumping role also applies to phagosome-lysosome fusion. Surprisingly, endo(lyso)somes mouse embryonic fibroblasts lacking a3...
We have investigated the interactions occurring between prelysosomal compartment, PLC/late endosome, and terminal lysosomes using an approach that allowed us to internalize deliver specific tracers these compartments, look for evidence of their meeting. After internalization sucrose, (sucrosomes), but not endosomes, became significantly swollen visible in light microscope. If invertase is then added medium it reaches where cleaves sucrose into fructose glucose. These sugars, unlike can be...
Focal adhesions (FAs) control cell shape and motility, which are important processes that underlie a wide range of physiological functions. FA dynamics is regulated by cytoskeleton, motor proteins small GTPases. Kinectin an integral endoplasmic reticulum (ER) membrane protein extends the ER along microtubules. Here, we investigated influence on within cellular lamella disrupting kinectin–kinesin interaction overexpressing minimal domain kinectin in cells. This perturbation resulted...
We have raised a monoclonal antibody (mAb) (HFD9) that detects 28 kDa protein (p28) enriched in the Golgi membrane. p28 was localized to perinuclear region all cell lines thus far examined. Its localization confirmed by its colocalization with markers using indirect immunofluorescence microscopy. Immunogold labelling demonstrates majority of on cis-Golgi and associated structures. Two independent experiments demonstrate epitope recognized mAb HFD9 is exposed cytosol. Extraction membranes...
Highly cytotoxic C7-modified colchicine analogues, exemplified by tubuloclustin, promote microtubule disassembly followed the formation of very stable tubulin clusters, both in vitro and cells. The proposed mechanism action tubuloclustin its beyond that colchicine, includes additional specific interactions with α-tubulin subunit.
Plasmodium falciparum invades human red blood cells (RBC), while Babesia divergens infects bovine and, occasionally, RBC. The mammalian RBC is normally unable to endocytose or phagocytose and the events leading invasion are incompletely understood. Initially, both parasites surrounded by plasma membrane-derived parasitophorous vacuolar membrane (PVM) that formed during invasion. In P. falciparum-infected RBC, PVM persists at least until parasite replication completed whereas it has been...
ABSTRACT Interspecies cell fusion was used to compare protein intermixing within the mannose 6-phosphate receptor (MPR)-enriched pre-lysosome compartment (PLC) and MPR-negative lysosomal compartment. Both compartments were positive for glycoprotein (Igp) membrane markers but morphologically distinct In most experiments, rat-mouse syncytia formed by u.v.-inactivated Sindbis virus-mediated fusion. By immunogold electron microscopy of syncytia, extensive species-specific proteins observed in...
We previously reported the isolation of a rat cDNA clone encoding protein with significant sequence homology to B isoform human myo-inositol 1,4,5-trisphosphate 3-kinase (IP3 B); this was thus designated IP3 [Thomas, Brake, Luzio, Stanley and Banting (1994) Biochim. Biophys. Acta 1220, 219–222]. However, no kinase had been shown generate physiologically important inositol tetrakisphosphate, i.e. 1,3,4,5-tetrakisphosphate. now present direct evidence that putative is genuinely an 3-kinase....
Cryo-sectioning procedures, initially developed by Tokuyasu, have been successfully improved for tissues and cultured cells, enabling efficient protein localization on the ultrastructural level. Without a standard procedure applicable to any sample, currently existing protocols must be individually modified each model organism or asymmetric sample. Here, we describe our method that enables reproducible cryo-sectioning of Caenorhabditis elegans larvae/adults embryos. We established...
Background Actin assembly on biological membranes is a poorly understood process. We have previously shown that phagosomal could induce actin in the presence of thymosin β4 (an sequestering protein inhibits nonspecific nucleation), via barbed ends filaments. Methods Here, we developed an vitro system based fluorescein-labeled G (monomeric) and flow cytometry analysis, which allowed us to quantify de novo cytoplasmic side purified phagosomes. To standardize system, also used latex beads...
A case of infection with Corynebacterium ulcerans (C. ulcerans), resulted in the sudden death a previously healthy 73‐year‐old woman. Death from diphtheriae diphtheriae) is well‐documented. Fatalities following C. are unreported; this would appear to be first documented due such infection.
Abstract Background When purified phagosomes are incubated in the presence of actin under appropriate conditions, microfilaments start growing from membrane a process that is affected by ATP and lipid composition membrane. Isolated metabolically active organelles contain enzymes metabolites necessary for interconversion. Hence, addition ATP, lipids, to system alter steady-state phagosomal at same time nucleation initiated. Our aim was model all these processes parallel. Results We compiled...
Abstract The anti-biowarfare anthrax and plague vaccines require repeated dosing to achieve adequate protection. To test the hypothesis that this limited immunogenicity results from nature of vaccine interactions with host innate immune system, we investigated molecular cellular between vaccines, dendritic cells (DCs), T explored potential for adjuvants (pertussis) boost induction immunity. Human monocyte-derived DCs were matured in presence analyzed their ability induce Th1/Th2 development...
Summary In July 2015 Professor K.T. Tokuyasu passed away in San Diego giving us the opportunity to reflect on contribution this electron microscopist made field of immunocytochemistry. His work provided a sensitive, minimally invasive approach producing thin sections biological material for labeling with antibodies. has been applied wide range applications and important information cellular processes.
In July 2015 Professor K.T. Tokuyasu passed away in San Diego giving us the opportunity to reflect on contribution this electron microscopist made field of immunocytochemistry. His work provided a sensitive, minimally invasive approach producing thin sections biological material for labeling with antibodies. has been applied wide range applications and important information cellular processes.
Abstract An investigation of the possible interactions between combinations vaccines and pyridostigmine bromide (PB) has been undertaken in guinea pig. This study is part a research programme funded by UK Government to determine any effects pretreatment regimes given Forces during Persian Gulf conflict 1990–1991. The was designed simulate PB administration model multiple vaccination protocols that were experienced Forces, modelling ‘worst case’ situation which all ten administered within...