Avian flu: influenza virus receptors in the human airway.
AuthorsShinya K,Ebina M,Yamada S,Ono M,Kasai N,Kawaoka Y
JournalNature
PubMed ID16554799
The membrane-bound histidine acid phosphatase TbMBAP1 is essential for endocytosis and membrane recycling in Trypanosoma brucei.
AuthorsEngstler M, Weise F, Bopp K, Grünfelder CG, Günzel M, Heddergott N, Overath P
JournalJ Cell Sci
PubMed ID15855239
'In the parasitic protozoan Trypanosoma brucei, endocytosis and exocytosis occur exclusively at an invagination of the plasma membrane around the base of the flagellum, called the flagellar pocket, which actively communicates by vesicular membrane flow with cisternal/tubulovesicular endosomes. The division of the cell surface into three morphologically distinct sub-domains and ... More
Cyclin I protects podocytes from apoptosis.
AuthorsGriffin SV, Olivier JP, Pippin JW, Roberts JM, Shankland SJ
JournalJ Biol Chem
PubMed ID16847066
'The limited regenerative capacity of the glomerular podocyte following injury underlies the development of glomerulosclerosis and progressive renal failure in a diverse range of kidney diseases. We discovered that, in the kidney, cyclin I is uniquely expressed in the glomerular podocyte, and have constructed cyclin I knock-out mice to explore ... More
Identification of nicotinic acetylcholine receptor recycling and its role in maintaining receptor density at the neuromuscular junction in vivo.
AuthorsBruneau E, Sutter D, Hume RI, Akaaboune M
JournalJ Neurosci
PubMed ID16251443
'In the CNS, receptor recycling is critical for synaptic plasticity; however, the recycling of receptors has never been observed at peripheral synapses. Using a novel imaging technique, we show here that nicotinic acetylcholine receptors (AChRs) recycle into the postsynaptic membrane of the neuromuscular junction. By sequentially labeling AChRs with biotin-bungarotoxin ... More
Development of homogeneous binding assays based on fluorescence resonance energy transfer between quantum dots and Alexa Fluor fluorophores.
AuthorsNikiforov TT, Beechem JM
JournalAnal Biochem
PubMed ID16860286
'We studied the fluorescence resonance energy transfer (FRET) between quantum dots emitting at 565, 605, and 655 nm as energy donors and Alexa Fluor fluorophores with absorbance maxima at 594, 633, 647, and 680 nm as energy acceptors. As a first step, we prepared covalent conjugates between all three types ... More
Targeting green fluorescent protein to dendritic membrane in central neurons.
'Dendritic and axonal processes are input and output sites, respectively, of neuronal information, and detailed visualization of these processes may be indispensable for elucidating the neuronal circuits and revealing the principles of neuronal functions. To establish a method for completely visualizing dendritic processes, we first developed green fluorescent protein (GFP)-based ... More
Lectin binding profiles of SSEA-4 enriched, pluripotent human embryonic stem cell surfaces.
AuthorsVenable A, Mitalipova M, Lyons I, Jones K, Shin S, Pierce M, Stice S,
JournalBMC Dev Biol
PubMed ID16033656
'BACKGROUND: Pluripotent human embryonic stem cells (hESCs) have the potential to form every cell type in the body. These cells must be appropriately characterized prior to differentiation studies or when defining characteristics of the pluripotent state. Some developmentally regulated cell surface antigens identified by monoclonal antibodies in a variety of ... More
Cell surface markers in human embryonic stem cells.
AuthorsRao RR, Johnson AV, Stice SL,
JournalMethods Mol Biol
PubMed ID18453248
'The pluripotent nature of human embryonic stem cells (hESCs) is based on their potential to form every cell type in the body. Prior to use in directed differentiation strategies, these cells need to be thoroughly characterized. The large number of glycoproteins and carbohydrates that exist on the cell surface provide ... More
Membrane properties and synaptic connectivity of fast-spiking interneurons in rat ventral striatum.
AuthorsTaverna S, Canciani B, Pennartz CM
JournalBrain Res
PubMed ID17459351
'In vitro patch-clamp recordings were made to study the membrane properties and synaptic connectivity of fast-spiking interneurons in rat ventral striatum. Using a whole-cell configuration in acutely prepared slices, fast-spiking interneurons were recognized based on their firing properties and their morphological phenotype was confirmed by immunocytochemistry. Membrane properties of fast-spiking ... More
Expression of CD34 and Myf5 defines the majority of quiescent adult skeletal muscle satellite cells.
AuthorsBeauchamp JR, Heslop L, Yu DS, Tajbakhsh S, Kelly RG, Wernig A, Buckingham ME, Partridge TA, Zammit PS
JournalJ Cell Biol
PubMed ID11121437
'Skeletal muscle is one of a several adult post-mitotic tissues that retain the capacity to regenerate. This relies on a population of quiescent precursors, termed satellite cells. Here we describe two novel markers of quiescent satellite cells: CD34, an established marker of hematopoietic stem cells, and Myf5, the earliest marker ... More
Eph tyrosine kinase receptor EphA4 is required for the topographic mapping of the corticospinal tract.
AuthorsCanty AJ, Greferath U, Turnley AM, Murphy M
JournalProc Natl Acad Sci U S A
PubMed ID17030822
'Fine movement in the body is controlled by the motor cortex, which signals in a topographically specific manner to neurons in the spinal cord by means of the corticospinal tract (CST). How the correct topography of the CST is established is unknown. To investigate the possibility that the Eph tyrosine ... More
Isolation of anti-CD22 Fv with high affinity by Fv display on human cells.
AuthorsHo M, Nagata S, Pastan I
JournalProc Natl Acad Sci U S A
PubMed ID16763048
'In vitro antibody affinity maturation has generally been achieved by display of mouse or human antibodies on the surface of microorganisms (phage, bacteria, and yeast). However, problems with protein folding, posttranslational modification, and codon usage still limit the number of improved antibodies that can be obtained. An ideal system would ... More
Nanoparticles as fluorescence labels: is size all that matters?
AuthorsSwift JL, Cramb DT,
JournalBiophys J
PubMed ID18390610
'Fluorescent labels are often used in bioassays as a means to detect and characterize ligand-receptor binding. This is due in part to the inherently high sensitivity of fluorescence-based technology and the relative accessibility of the technique. There is often little concern raised as to whether or not the fluorescent label ... More
Patterning enzymes inside microfluidic channels via photoattachment chemistry.
AuthorsHolden MA, Jung SY, Cremer PS
JournalAnal Chem
PubMed ID15053641
'We have developed a general method for photopatterning well-defined patches of enzymes inside a microfluidic device at any location. First, a passivating protein layer was adsorbed to the walls and floor of a poly(dimethylsiloxane)/glass microchannel. The channel was then filled with an aqueous biotin-linked dye solution. Using an Ar+/Kr+ laser, ... More
Angiotensin II stimulates spinally projecting paraventricular neurons through presynaptic disinhibition.
AuthorsLi DP, Chen SR, Pan HL
JournalJ Neurosci
PubMed ID12832527
'Paraventricular nucleus (PVN) neurons that project to the spinal cord are important in the control of sympathetic outflow. Angiotensin II (Ang II) can stimulate PVN neurons, but its cellular mechanisms are not clear. In this study, we determined the effect of Ang II on the excitatory and inhibitory synaptic inputs ... More
Costimulation of CD8alphabeta T cells by NKG2D via engagement by MIC induced on virus-infected cells.
'NKG2D is an activating receptor that stimulates innate immune responses by natural killer cells upon engagement by MIC ligands, which are induced by cellular stress. Because NKG2D is also present on most CD8alphabeta T cells, it may modulate antigen-specific T cell responses, depending on whether MIC molecules--distant homologs of major ... More
FRET or no FRET: a quantitative comparison.
AuthorsBerney C, Danuser G
JournalBiophys J
PubMed ID12770904
'Fluorescence resonance energy transfer (FRET) is a technique used to measure the interaction between two molecules labeled with two different fluorophores (the donor and the acceptor) by the transfer of energy from the excited donor to the acceptor. In biological applications, this technique has become popular to qualitatively map protein-protein ... More
Fluorescence-based staining for tartrate-resistant acidic phosphatase (TRAP) in osteoclasts combined with other fluorescent dyes and protocols.
AuthorsFilgueira L
JournalJ Histochem Cytochem
PubMed ID14966208
Osteoclasts are the only bone-resorbing cells. In addition to other specific properties, osteoclasts are characterized by their expression of tartrate-resistant acidic phosphatase (TRAP), which is usually detected using a histochemical method for light microscopy. Using ELF97 phosphatase substrate, this study describes a new fluorescence-based method for TRAP detection. The fluorescence-based ... More
A microrotary motor powered by bacteria.
AuthorsHiratsuka Y, Miyata M, Tada T, Uyeda TQ
JournalProc Natl Acad Sci U S A
PubMed ID16950878
Biological molecular motors have a number of unique advantages over artificial motors, including efficient conversion of chemical energy into mechanical work and the potential for self-assembly into larger structures, as is seen in muscle sarcomeres and bacterial and eukaryotic flagella. The development of an appropriate interface between such biological materials ... More
Shifting foci of hematopoiesis during reconstitution from single stem cells.
AuthorsCao YA, Wagers AJ, Beilhack A, Dusich J, Bachmann MH, Negrin RS, Weissman IL, Contag CH
JournalProc Natl Acad Sci U S A
PubMed ID14688412
To reveal the early events and dynamics of hematopoietic reconstitution in living animals in real-time, we used bioluminescence imaging to monitor engraftment from single luciferase-labeled hematopoietic stem cells (HSC) in irradiated recipients. Transplanted HSC generated discrete foci in the spleen and bone marrow (BM), at a frequency that correlated with ... More
An ent-kaurene that inhibits mitotic chromosome movement and binds the kinetochore protein ran-binding protein 2.
AuthorsRundle NT, Nelson J, Flory MR, Joseph J, Th'ng J, Aebersold R, Dasso M, Andersen RJ, Roberge M
JournalACS Chem Biol
PubMed ID17168522
Using a chemical genetics screen, we have identified ent-15-oxokaurenoic acid (EKA) as a chemical that causes prolonged mitotic arrest at a stage resembling prometaphase. EKA inhibits the association of the mitotic motor protein centromeric protein E with kinetochores and inhibits chromosome movement. Unlike most antimitotic agents, EKA does not inhibit ... More
Detection and quantification of protein biomarkers from fewer than 10 cells.
AuthorsNettikadan S, Radke K, Johnson J, Xu J, Lynch M, Mosher C, Henderson E,
JournalMol Cell Proteomics
PubMed ID16489239
The use of antibody microarrays continues to grow rapidly due to the recent advances in proteomics and automation and the opportunity this combination creates for high throughput multiplexed analysis of protein biomarkers. However, a primary limitation of this technology is the lack of PCR-like amplification methods for proteins. Therefore, to ... More
AuthorsYoum YH, Yang H, Sun Y, Smith RG, Manley NR, Vandanmagsar B, Dixit VD,
JournalJ Biol Chem
PubMed ID19054770
With progressive aging, adipocytes are the major cell types that constitute the bulk of thymic microenvironment. Understanding the origin of thymic adipocytes and mechanisms responsible for age-related thymic adiposity is thus germane for the design of long lasting thymic rejuvenation strategies. We have recently identified that ghrelin, an orexigenic anti-inflammatory ... More
Targeting the variable surface of African trypanosomes with variant surface glycoprotein-specific, serum-stable RNA aptamers.
AuthorsLorger M, Engstler M, Homann M, Göringer HU
JournalEukaryot Cell
PubMed ID12582125
African trypanosomes cause sleeping sickness in humans and Nagana in cattle. The parasites multiply in the blood and escape the immune response of the infected host by antigenic variation. Antigenic variation is characterized by a periodic change of the parasite protein surface, which consists of a variant glycoprotein known as ... More
Ultrathin cryosections: an important tool for immunofluorescence and correlative microscopy.
AuthorsTakizawa T, Robinson JM
JournalJ Histochem Cytochem
PubMed ID12754282
Here we show that ultrathin cryosections of placental tissue can be used as a substrate in immunofluorescence experiments. A high degree of spatial resolution can be achieved in these preparations because there is essentially no out-of-focus fluorescence. Therefore, immunofluorescence microscopy using ultrathin cryosections provides a very useful method for determining ... More
Dynein is required for receptor sorting and the morphogenesis of early endosomes.
AuthorsDriskell OJ, Mironov A, Allan VJ, Woodman PG
JournalNat Cell Biol
PubMed ID17173037
The early endosome is organised into domains to ensure the separation of cargo. Activated mitogenic receptors, such as epidermal growth factor (EGF) receptor, are concentrated into vacuoles enriched for the small GTPase Rab5, which progressively exclude nutrient receptors, such as transferrin receptor, into neighbouring tubules. These vacuoles become enlarged, increase ... More
Phosphoinositide 3-kinase activation by Igbeta controls de novo formation of an antigen-processing compartment.
AuthorsGranboulan M, Lankar D, Raposo G, Bonnerot C, Hivroz C
JournalJ Biol Chem
PubMed ID12459553
Antigens that bind B cell antigen receptor (BCR) are preferentially and rapidly processed for antigen presentation. The BCR is a multimeric complex containing a signaling module composed of Igalpha and Igbeta. Signaling pathways implicated in antigen presentation through the BCR are ill defined. Here we demonstrate that phosphoinositide 3-kinase (PI3K) ... More
Actin-rich spherical extrusion induced in okadaic acid-treated K562 cells by crosslinking of membrane microdomains.
AuthorsBaba T, Udaka K, Terada N, Ueda H, Fujii Y, Ohno S, Sato SB
JournalJ Histochem Cytochem
PubMed ID12533533
Interconnection between surface microdomains and the actin cytoskeleton is vital to various cellular activities. We studied the responses of okadaic acid (OKA)-treated K562 leukemia cells to crosslinking of membrane microdomains. Although OKA alone induced clustering of surface-bound F-actin, addition of a biotinylated poly(ethylene glycol) derivative of cholesterol (bPEG-Chol) and subsequent ... More
Particle formation by a conserved domain of the herpes simplex virus protein VP22 facilitating protein and nucleic acid delivery.
AuthorsNormand N, van Leeuwen H, O'Hare P
JournalJ Biol Chem
PubMed ID11278656
VP22, a structural protein of herpes simplex virus, exhibits unusual trafficking properties which we proposed might be exploited in gene and protein delivery applications. To pursue the use of the protein itself for cargo delivery into cells, we developed an expression system for the C-terminal half of VP22, residues 159-301 ... More
Activated antigen-specific CD8+ T cells persist in the lungs following recovery from respiratory virus infections.
The poor correlation between cellular immunity to respiratory virus infections and the numbers of memory CD8(+) T cells in the secondary lymphoid organs suggests that there may be additional reservoirs of T cell memory to this class of infection. Here we identify a substantial population of Ag-specific T cells in ... More
Pseudomonas aeruginosa exploits a PIP3-dependent pathway to transform apical into basolateral membrane.
AuthorsKierbel A, Gassama-Diagne A, Rocha C, Radoshevich L, Olson J, Mostov K, Engel J
JournalJ Cell Biol
PubMed ID17403925
Pseudomonas aeruginosa, an important human pathogen, preferentially binds and enters injured cells from the basolateral (BL) surface. We previously demonstrated that activation of phosphatidylinositol 3-kinase (PI3K) and Akt are necessary and sufficient for P. aeruginosa entry from the apical (AP) surface and that AP addition of phosphatidylinositol 3,4,5-trisphosphate (PIP3) is ... More
ETL, a novel seven-transmembrane receptor that is developmentally regulated in the heart. ETL is a member of the secretin family and belongs to the epidermal growth factor-seven-transmembrane subfamily.
AuthorsNechiporuk T, Urness LD, Keating MT
JournalJ Biol Chem
PubMed ID11050079
Using differential display of rat fetal and postnatal cardiomyocytes, we have identified a novel seven-transmembrane receptor, ETL. The cDNA-predicted amino acid sequence of ETL indicated that it encodes a 738-aa protein composed of a large extracellular domain with epidermal growth factor (EGF)-like repeats, a seven-transmembrane domain, and a short cytoplasmic ... More
Improved Golgi-like visualization in retrogradely projecting neurons after EGFP-adenovirus infection in adult rat and monkey.
AuthorsTomioka R, Rockland KS
JournalJ Histochem Cytochem
PubMed ID16344324
An adenovirus vector was generated using a neuron-specific promoter synapsin I and enhanced green fluorescent protein (EGFP) reporter (AdSynEGFP). In addition, two modifications were identified that resulted in robust and reliable retrograde transport and EGFP expression after injection of the virus into three different brain regions in adult rats (medial ... More
Evidence that beta3 integrin-induced Rac activation involves the calpain-dependent formation of integrin clusters that are distinct from the focal complexes and focal adhesions that form as Rac and RhoA become active.
AuthorsBialkowska K, Kulkarni S, Du X, Goll DE, Saido TC, Fox JE
JournalJ Cell Biol
PubMed ID11062268
Interaction of integrins with the extracellular matrix leads to transmission of signals, cytoskeletal reorganizations, and changes in cell behavior. While many signaling molecules are known to be activated within Rac-induced focal complexes or Rho-induced focal adhesions, the way in which integrin-mediated adhesion leads to activation of Rac and Rho is ... More
Simultaneous detection of EGFP and cell surface markers by fluorescence microscopy in lymphoid tissues.
AuthorsKusser KL, Randall TD
JournalJ Histochem Cytochem
PubMed ID12502749
Enhanced GFP (EGFP) is a powerful tool for the visualization of tagged proteins and transfected cells and is easily detected by fluorescence microscopy or flow cytometry in living cells. However, soluble EGFP molecules can be lost if cell integrity is disrupted by freezing, sectioning, or permeablization. Furthermore, the fluorescence of ... More
Endocytosis of a glycosylphosphatidylinositol-anchored protein via clathrin-coated vesicles, sorting by default in endosomes, and exocytosis via RAB11-positive carriers.
AuthorsGrünfelder CG, Engstler M, Weise F, Schwarz H, Stierhof YD, Morgan GW, Field MC, Overath P
JournalMol Biol Cell
PubMed ID12802073
Recently, proteins linked to glycosylphosphatidylinositol (GPI) residues have received considerable attention both for their association with lipid microdomains and for their specific transport between cellular membranes. Basic features of trafficking of GPI-anchored proteins or glycolipids may be explored in flagellated protozoan parasites, which offer the advantage that their surface is ... More
Donut-like topology of synaptic vesicles with a central cluster of mitochondria wrapped into membrane protrusions: a novel structure-function module of the adult calyx of Held.
AuthorsWimmer VC, Horstmann H, Groh A, Kuner T
JournalJ Neurosci
PubMed ID16399677
Structural and functional properties of synapses are intricately and reciprocally coupled. To cope with the functional requirements in auditory processing, the calyx of Held developed distinct structural specializations such as a large number of active zones, large size, elaborate morphology, and defined distribution of ion channels. These specializations typically appear ... More
Dkk-1-derived synthetic peptides and lithium chloride for the control and recovery of adult stem cells from bone marrow.
AuthorsGregory CA, Perry AS, Reyes E, Conley A, Gunn WG, Prockop DJ
JournalJ Biol Chem
PubMed ID15504735
It is established that human mesenchymal stem cells (hMSCs) from bone marrow are a source of osteoblast progenitors in vivo and under appropriate conditions, differentiate into osteoblasts ex vivo. Because hMSCs are recovered by iliac crest aspirate and enriched by virtue of their adherence to tissue culture plastic, the cells ... More
CD4 receptor localized to non-raft membrane microdomains supports HIV-1 entry. Identification of a novel raft localization marker in CD4.
AuthorsPopik W, Alce TM
JournalJ Biol Chem
PubMed ID14570906
Despite the preferential localization of CD4 to lipid rafts, the significance and role of these microdomains in HIV-1 entry is still controversial. The possibility that CD4, when localized to non-raft domains, might be able to support virus entry cannot be excluded. Because disintegration of rafts by extraction of cellular cholesterol ... More
Disturbed cross talk between insulin-like growth factor I and AMP-activated protein kinase as a possible cause of vascular dysfunction in the amyloid precursor protein/presenilin 2 mouse model of Alzheimer's disease.
AuthorsLopez-Lopez C, Dietrich MO, Metzger F, Loetscher H, Torres-Aleman I
JournalJ Neurosci
PubMed ID17251422
Cerebrovascular dysfunction appears to be involved in Alzheimer's disease (AD). In double mutant amyloid precursor protein/presenilin 2 (APP/PS2) mice, a transgenic model of AD, vessel homeostasis is disturbed. These mice have elevated levels of vascular endothelial growth factor (VEGF) and increased brain endothelial cell division but abnormally low brain vessel ... More
Novel fluorescence-based approaches for the study of biogenic amine transporter localization, activity, and regulation.
Pre-synaptic norepinephrine (NE) and dopamine (DA) transporters (NET and DAT) terminate catecholamine synaptic transmission through reuptake of released neurotransmitter. Recent studies reveal that NET and DAT are tightly regulated by receptor and second messenger-linked signaling pathways. Common approaches for studying these transporters involve use of radiolabeled substrates or antagonists, methods ... More