Evidence that Ca(2+) cycling by the plasma membrane Ca(2+)-ATPase increases the 'excitability' of the extracellular Ca(2+)-sensing receptor.
AuthorsDe Luisi A, Hofer AM
JournalJ Cell Sci
PubMed ID12640037
'The extracellular Ca(2+)-sensing receptor (CaR) is a widely expressed G-protein-coupled receptor that translates information about [Ca(2+)] in the extracellular milieu to the interior of the cell, usually via intracellular Ca(2+) signaling pathways. Using fura-2 imaging of cytoplasmic [Ca(2+)], we observed that HEK293 cells expressing CaR oscillated readily under conditions permissive ... More
Viral nanoparticles as tools for intravital vascular imaging.
AuthorsLewis JD, Destito G, Zijlstra A, Gonzalez MJ, Quigley JP, Manchester M, Stuhlmann H
JournalNat Med
PubMed ID16501571
'A significant impediment to the widespread use of noninvasive in vivo vascular imaging techniques is the current lack of suitable intravital imaging probes. We describe here a new strategy to use viral nanoparticles as a platform for the multivalent display of fluorescent dyes to image tissues deep inside living organisms. ... More
N-glycans are direct determinants of CFTR folding and stability in secretory and endocytic membrane traffic.
'N-glycosylation, a common cotranslational modification, is thought to be critical for plasma membrane expression of glycoproteins by enhancing protein folding, trafficking, and stability through targeting them to the ER folding cycles via lectin-like chaperones. In this study, we show that N-glycans, specifically core glycans, enhance the productive folding and conformational ... More
On the use of retrograde tracers for identification of axon collaterals with multiple fluorescent retrograde tracers.
AuthorsSchofield BR, Schofield RM, Sorensen KA, Motts SD
JournalNeuroscience
PubMed ID17379419
'A common method for identifying collateral projections is to inject different retrograde tracers into two targets and examine labeled cells for the presence of both tracers. Double-labeled cells are considered to have collateral projections to the two injection sites. This method is widely considered to underestimate the extent of collaterals. ... More
A role for phosphoinositide 3-kinase in the completion of macropinocytosis and phagocytosis by macrophages.
AuthorsAraki N, Johnson MT, Swanson JA
JournalJ Cell Biol
PubMed ID8947549
'Phosphoinositide 3-kinase (PI 3-kinase) has been implicated in growth factor signal transduction and vesicular membrane traffic. It is thought to mediate the earliest steps leading from ligation of cell surface receptors to increased cell surface ruffling. We show here that inhibitors of PI 3-kinase inhibit endocytosis in macrophages, not by ... More
Regional crypt function in rat large intestine in relation to fluid absorption and growth of the pericryptal sheath.
AuthorsNaftalin RJ, Pedley KC
JournalJ Physiol
PubMed ID9831728
'1. Confocal microscopic studies of rat colonic mucosa showed that the pericryptal sheath surrounding distal colonic crypts is an effective barrier both to dextran and NaCl movement, whereas no such structure surrounds the caecal crypts. 2. The distal colonic pericryptal barrier was functionally demonstrated by accumulation of Sodium Green within ... More
The pH of the digestive vacuole of Plasmodium falciparum is not associated with chloroquine resistance.
AuthorsHayward R, Saliba KJ, Kirk K
JournalJ Cell Sci
PubMed ID16492710
'Chloroquine resistance in the human malaria parasite, Plasmodium falciparum, arises from decreased accumulation of the drug in the ;digestive vacuole'' of the parasite, an acidic compartment in which chloroquine exerts its primary toxic effect. It has been proposed that changes in the pH of the digestive vacuole might underlie the ... More
Delivery of macromolecules into live cells by simple co-incubation with a peptide.
AuthorsLee YJ, Erazo-Oliveras A, Pellois JP,
JournalChembiochem
PubMed ID20029930
'n this report, we test the hypothesis that optimized cell-penetrating peptides (CPPs) might deliver macromolecules to the cytosol of live cells by simple co-incubation and without the requirement for any type of conjugation, whether covalent or noncovalent. This hypothesis is based on the observation that the binding of TAT and ... More
Short-range signaling by candidate morphogens of the TGF beta family and evidence for a relay mechanism of induction.
AuthorsReilly KM, Melton DA
JournalCell
PubMed ID8797821
'The specification and patterning of cell fates by a morphogen gradient is a unifying theme of developmental biology, yet little evidence exists for the presence of gradients in vivo or to show how such putative gradients form. Vg1 and activin are candidate morphogens involved in Xenopus mesoderm induction. This study ... More
Calpain activity promotes the sealing of severed giant axons.
'A barrier (seal) must form at the cut ends of a severed axon if a neuron is to survive and eventually regenerate. Following severance of crayfish medial giant axons in physiological saline, vesicles accumulate at the cut end and form a barrier (seal) to ion and dye diffusion. In contrast, ... More
Requirement for annexin A1 in plasma membrane repair.
AuthorsMcNeil AK, Rescher U, Gerke V, McNeil PL
JournalJ Biol Chem
PubMed ID16984915
'Ca2+ entering a cell through a torn or disrupted plasma membrane rapidly triggers a combination of homotypic and exocytotic membrane fusion events. These events serve to erect a reparative membrane patch and then anneal it to the defect site. Annexin A1 is a cytosolic protein that, when activated by micromolar ... More
Mammalian reovirus, a nonfusogenic nonenveloped virus, forms size-selective pores in a model membrane.
AuthorsAgosto MA, Ivanovic T, Nibert ML
JournalProc Natl Acad Sci U S A
PubMed ID17053074
During cell entry, reovirus particles with a diameter of 70-80 nm must penetrate the cellular membrane to access the cytoplasm. The mechanism of penetration, without benefit of membrane fusion, is not well characterized for any such nonenveloped animal virus. Lysis of RBCs is an in vitro assay for the membrane ... More
Membrane perforations inhibit lysosome fusion by altering pH and calcium in Listeria monocytogenes vacuoles.
AuthorsShaughnessy LM, Hoppe AD, Christensen KA, Swanson JA
JournalCell Microbiol
PubMed ID16611227
Listeria monocytogenes (Lm) evade microbicidal defences inside macrophages by secreting a pore-forming cytolysin listeriolysin O (LLO), which allows Lm to escape vacuoles. LLO also inhibits Lm vacuole fusion with lysosomes, which indicates LLO alters vacuole chemistry prior to release of Lm into cytoplasm. Using fluorescent probes to measure membrane permeability, ... More
Activation-dependent and activation-independent localisation of calmodulin to the mitotic apparatus during the first cell cycle of the Lytechinus pictus embryo.
AuthorsWilding M, Torok K, Whitaker M
JournalZygote
PubMed ID8903791
We have used confocal microscopy and a fluorescent calmodulin probe to examine the mechanism of localisation of calmodulin during the first cell cycle of the sea urchin zygote. Using fluorescein-calmodulin, calmodulin can be observed within the nucleus and interphase astral microtubule arrays as cells approach mitosis. During mitosis, calmodulin redistributes ... More
A membrane-targeted BID BCL-2 homology 3 peptide is sufficient for high potency activation of BAX in vitro.
The multidomain pro-apoptotic proteins BAX and BAK constitute an essential gateway to mitochondrial dysfunction and programmed cell death. Among the "BCL-2 homology (BH) 3-only" members of pro-apoptotic proteins, truncated BID (tBID) has been implicated in direct BAX activation, although an explicit molecular mechanism remains elusive. We find that BID BH3 ... More
Functional studies of the kidney of living animals using multicolor two-photon microscopy.
AuthorsDunn KW, Sandoval RM, Kelly KJ, Dagher PC, Tanner GA, Atkinson SJ, Bacallao RL, Molitoris BA
JournalAm J Physiol Cell Physiol
PubMed ID12176747
Optical microscopy, when applied to living animals, provides a powerful means of studying cell biology in the most physiologically relevant setting. The ability of two-photon microscopy to collect optical sections deep into biological tissues has opened up the field of intravital microscopy to high-resolution studies of the brain, lens, skin, ... More
Movement of the free catalytic subunit of cAMP-dependent protein kinase into and out of the nucleus can be explained by diffusion.
AuthorsHarootunian AT, Adams SR, Wen W, Meinkoth JL, Taylor SS, Tsien RY
JournalMol Biol Cell
PubMed ID8298196
The catalytic (C) subunit of cyclic AMP (cAMP) dependent protein kinase (PKA) has previously been shown to enter and exit the nucleus of cells when intracellular cAMP is raised and lowered, respectively. To determine the mechanism of nuclear translocation, fluorescently labeled C subunit was injected into living REF52 fibroblasts either ... More
"Synchronized" endocytosis and intracellular sorting in alveolar macrophages: the early sorting endosome is a transient organelle.
AuthorsWard DM, Perou CM, Lloyd M, Kaplan J
JournalJ Cell Biol
PubMed ID7775570
Incubation of alveolar macrophages in hypoosmotic K(+)-containing buffers results in persistent cell swelling and an inability to undergo regulatory volume decrease. We demonstrate that cells incubated in hypo-K+ show an inhibition of endocytosis without any observed alteration in recycling. The inhibition of endocytosis affected all forms of membrane internalization, receptor ... More
Legionella pneumophila replication vacuoles mature into acidic, endocytic organelles.
AuthorsSturgill-Koszycki S, Swanson MS
JournalJ Exp Med
PubMed ID11067875
After ingestion by macrophages, Legionella pneumophila inhibits acidification and maturation of its phagosome. After a 6-10-h lag period, the bacteria replicate for 10-14 h until macrophage lysis releases dozens of progeny. To examine whether the growth phase of intracellular L. pneumophila determines the fate of its phagosome, interactions between the ... More
Crayfish medial giant axons (MGAs) transected in physiological saline form vesicles which interact with each other, pre-existing vesicles, and/or with the plasmalemma to form an electrical and a physical barrier that seals a cut axonal end within 60 min. The formation of this barrier (seal) was assessed by measuring the ... More
Changes in the cytoplasmic structure of CTLs during target cell recognition and killing.
AuthorsWaters JB, Oldstone MB, Hahn KM
JournalJ Immunol
PubMed ID8871637
CTL play a critical role in immune defense by recognizing and killing virally infected or tumor cells. In this report, the structure of cytoplasm within living CTL was monitored during CTL killing of target cells. Living CTL were simultaneously loaded with fluorescent 70,000- and 10,000-kDa dextran particles. The relative distribution ... More
Identification of PLCgamma-dependent and -independent events during fertilization of sea urchin eggs.
AuthorsCarroll DJ, Albay DT, Terasaki M, Jaffe LA, Foltz KR
JournalDev Biol
PubMed ID9986735
At fertilization, sea urchin eggs undergo a series of activation events, including a Ca2+ action potential, Ca2+ release from the endoplasmic reticulum, an increase in intracellular pH, sperm pronuclear formation, MAP kinase dephosphorylation, and DNA synthesis. To examine which of these events might be initiated by activation of phospholipase Cgamma ... More
Exocytosis and endocytosis of small vesicles in PC12 cells studied with TEPIQ (two-photon extracellular polar-tracer imaging-based quantification) analysis.
AuthorsLiu TT, Kishimoto T, Hatakeyama H, Nemoto T, Takahashi N, Kasai H
JournalJ Physiol
PubMed ID16150796
We investigated exocytosis of PC12 cells using two-photon excitation imaging and extracellular polar tracers (TEP imaging) in the lateral membranes not facing the glass-cover slip. Upon photolysis of a caged Ca2+ compound, TEP imaging with FM1-43 (a polar membrane tracer) detected massive exocytosis of vesicles with a time constant of ... More
Comparative morphology of three types of projection-identified pyramidal neurons in the superficial layers of cat visual cortex.
AuthorsMatsubara JA, Chase R, Thejomayen M
JournalJ Comp Neurol
PubMed ID8866848
The morphology and dendritic organization of corticocortical neurons in the superficial layers of area 18 that project to area 17 were studied by intracellular injection of lucifer yellow in the fixed-slice preparation. This corticocortical population contains primarily standard pyramidal cells, but occasional nonpyramidal, modified, fusiform, star, and inverted pyramidal cells ... More
Sheet-Like Remodeling of the Transverse Tubular System in Human Heart Failure Impairs Excitation-Contraction Coupling and Functional Recovery by Mechanical Unloading.
Authors
JournalCirculation
PubMed ID28073805
The Physical Basis of Coordinated Tissue Spreading in Zebrafish Gastrulation.
Authors
JournalDev Cell
PubMed ID28216382
Small proline-rich protein 2A is a gut bactericidal protein deployed during helminth infection.
Authors
JournalScience
PubMed ID34735226
Mechanistic basis for multidrug resistance and collateral drug sensitivity conferred to the malaria parasite by polymorphisms in PfMDR1 and PfCRT.
Authors
JournalPLoS Biol
PubMed ID35507548
Sensitive detection of lysosomal membrane permeabilization by lysosomal galectin puncta assay.
Authors
JournalAutophagy
PubMed ID26114578
Bid, Bax, and lipids cooperate to form supramolecular openings in the outer mitochondrial membrane.
Authors
JournalCell
PubMed ID12419244
Bone marrow endothelial cells sustain a tumor-specific CD8+ T cell subset with suppressive function in myeloma patients.
Authors
JournalOncoimmunology
PubMed ID30546939
Astrocytic neogenin/netrin-1 pathway promotes blood vessel homeostasis and function in mouse cortex.
Authors
JournalJ Clin Invest
PubMed ID32853179
Cancer Cells Resist Mechanical Destruction in Circulation via RhoA/Actomyosin-Dependent Mechano-Adaptation.
Authors
JournalCell Rep
PubMed ID32187555
Spatiotemporally controlled induction of autophagy-mediated lysosome turnover.