A cluster of noninvoluting endocytic cells at the margin of the zebrafish blastoderm marks the site of embryonic shield formation.
AuthorsCooper MS,D'Amico LA
JournalDevelopmental biology
PubMed ID8948584
Intracellular fluid flow in rapidly moving cells.
AuthorsKeren K, Yam PT, Kinkhabwala A, Mogilner A, Theriot JA,
JournalNat Cell Biol
PubMed ID19767741
'Cytosolic fluid dynamics have been implicated in cell motility because of the hydrodynamic forces they induce and because of their influence on transport of components of the actin machinery to the leading edge. To investigate the existence and the direction of fluid flow in rapidly moving cells, we introduced inert ... More
Effect of phospholipid composition on an amphipathic peptide-mediated pore formation in bilayer vesicles.
AuthorsNicol F, Nir S, Szoka FC
JournalBiophys J
PubMed ID10653794
'To better understand the influence of phospholipid acyl-chain composition on the formation of pores by cytotoxic amphipathic helices in biological membranes, the leakage of aqueous contents induced by the synthetic peptide GALA (WEAALAEALAE ALAEHLAEALAEALEALAA) from large unilamellar phospholipid vesicles of various compositions has been studied. Peptide-mediated leakage was examined at ... More
Long distance pathways of diffusion for dextran along fibre bundles in brain. Relevance for volume transmission.
AuthorsBjelke B, England R, Nicholson C, Rice ME, Lindberg J, Zoli M, Agnati LF, Fuxe K
JournalNeuroreport
PubMed ID7543300
'Texas Red-labelled dextran with a mol. wt of 3000 g mol-1, a marker for the extracellular space, was injected unilaterally into the neostriatum of adult rats (0.3-30 micrograms microliter-1) and its distribution evaluated 1 min to 5 h later. Diffusion in the neuropil was observed with clearance starting after 30 ... More
Effect of cholesterol and charge on pore formation in bilayer vesicles by a pH-sensitive peptide.
AuthorsNicol F, Nir S, Szoka FC
JournalBiophys J
PubMed ID8968598
'The effect of cholesterol on the bilayer partitioning of the peptide GALA (WEAALAEALAEALAEHLAEALAEALEALAA) and its assembly into a pore in large unilamellar vesicles composed of neutral and negatively charged phospholipids has been determined. GALA undergoes a conformational change from a random coil to an amphipathic alpha-helix when the pH is ... More
In vivo diffusion analysis with quantum dots and dextrans predicts the width of brain extracellular space.
AuthorsThorne RG, Nicholson C
JournalProc Natl Acad Sci U S A
PubMed ID16567637
'Diffusion within the extracellular space (ECS) of the brain is necessary for chemical signaling and for neurons and glia to access nutrients and therapeutics; however, the width of the ECS in living tissue remains unknown. We used integrative optical imaging to show that dextrans and water-soluble quantum dots with Stokes-Einstein ... More
Intravital multiphoton microscopy of dynamic renal processes.
AuthorsMolitoris BA, Sandoval RM
JournalAm J Physiol Renal Physiol
PubMed ID15883167
'Recent advances in microscopy and optics, computer sciences, and the available fluorophores used to label molecules of interest have empowered investigators to utilize intravital two-photon microscopy to study the dynamic events within the functioning kidney. This emerging technique enables investigators to follow functional and structural alterations with subcellular resolution within ... More
Calcium entry initiates processes that restore a barrier to dye entry in severed earthworm giant axons.
After severance, axons can restore structural barriers that are necessary for recovery of their electrical function. In earthworm myelinated axons, such a barrier to dye entry is mediated by many vesicles and myelin-derived membranous structures. From time-lapse confocal fluorescence and DIC images, we now report that Ca2+ entry and not ... More
Fusion pore dynamics and insulin granule exocytosis in the pancreatic islet.
AuthorsTakahashi N, Kishimoto T, Nemoto T, Kadowaki T, Kasai H
JournalScience
PubMed ID12193788
Insulin secretion from intact mouse pancreatic islets was investigated with two-photon excitation imaging. Insulin granule exocytosis occurred mainly toward the interstitial space, away from blood vessels. The fusion pore was unusually stable with a lifetime of 1.8 seconds. Opening of the 1.4-nanometer-diameter pore was preceded by unrestricted lateral diffusion of ... More
Implications for dorsoventral axis determination from the zebrafish mutation janus.
AuthorsAbdelilah S, Solnica-Krezel L, Stainier DY, Driever W
JournalNature
PubMed ID8047167
THE mechanisms underlying the formation of dorsoventral polarity in the zebrafish Danio rerio are unknown. Here we describe the zebrafish recessive maternal-effect mutation janusm55. The mutant phenotype is a division of the blastoderm along the first cleavage plane into two detached half-sized blastoderms. Partial-axis bifurcation occurs in a subset of ... More
NAADP, cADPR and IP3 all release Ca2+ from the endoplasmic reticulum and an acidic store in the secretory granule area.
AuthorsGerasimenko JV, Sherwood M, Tepikin AV, Petersen OH, Gerasimenko OV
JournalJ Cell Sci
PubMed ID16410548
Inositol trisphosphate and cyclic ADP-ribose release Ca2+ from the endoplasmic reticulum via inositol trisphosphate and ryanodine receptors, respectively. By contrast, nicotinic acid adenine dinucleotide phosphate may activate a novel Ca2+ channel in an acid compartment. We show, in two-photon permeabilized pancreatic acinar cells, that the three messengers tested could each ... 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
Control of local actin assembly by membrane fusion-dependent compartment mixing.
AuthorsYu HY, Bement WM
JournalNat Cell Biol
PubMed ID17237773
Local actin assembly is associated with sites of exocytosis in processes ranging from phagocytosis to compensatory endocytosis. Here, we examine whether the trigger for actin-coat assembly around exocytosing Xenopus egg cortical granules is 'compartment mixing'--the union of the contents of the plasma membrane with that of the secretory granule membrane. ... More
The parasitophorous vacuole membrane surrounding intracellular Toxoplasma gondii functions as a molecular sieve.
AuthorsSchwab JC, Beckers CJ, Joiner KA
JournalProc Natl Acad Sci U S A
PubMed ID8290555
The obligate intracellular protozoan parasite Toxoplasma gondii creates and enters into a unique membrane-bounded cytoplasmic compartment, the parasitophorous vacuole, when invading mammalian host cells. By microinjecting polar fluorescent molecules into individual T. gondii-infected fibroblasts, we show here that the parasitophorous vacuole membrane (PVM) surrounding the parasite functions as a molecular ... More
Characterization of the interaction between zyxin and members of the Ena/vasodilator-stimulated phosphoprotein family of proteins.
Zyxin contains a proline-rich N-terminal domain that is similar to the C-terminal domain in the ActA protein of the bacteria, Listeria monocytogenes. We screened the entire amino acid sequence of human zyxin for Mena-interacting peptides and found that, as with ActA, proline-rich sequences were the sole zyxin sequences capable of ... More
Dynamic behavior of rod photoreceptor disks.
AuthorsChen C, Jiang Y, Koutalos Y
JournalBiophys J
PubMed ID12202366
Eukaryotic cells use membrane organelles, like the endoplasmic reticulum or the Golgi, to carry out different functions. Vertebrate rod photoreceptors use hundreds of membrane sacs (the disks) for the detection of light. We have used fluorescent tracers and single cell imaging to study the properties of rod photoreceptor disks. Labeling ... More
Differential distribution of dynamin isoforms in mammalian cells.
AuthorsCao H, Garcia F, McNiven MA
JournalMol Biol Cell
PubMed ID9725914
Dynamins are 100-kDa GTPases that are essential for clathrin-coated vesicle formation during receptor-mediated endocytosis. To date, three different dynamin genes have been identified, with each gene expressing at least four different alternatively spliced forms. Currently, it is unclear whether these different dynamin gene products perform distinct or redundant cellular functions. ... More
Axolemmal repair requires proteins that mediate synaptic vesicle fusion.
AuthorsDetrait E, Eddleman CS, Yoo S, Fukuda M, Nguyen MP, Bittner GD, Fishman HM
JournalJ Neurobiol
PubMed ID10945894
A damaged cell membrane is repaired by a seal that restricts entry or exit of molecules and ions to that of the level passing through an undamaged membrane. Seal formation requires elevation of intracellular Ca(2+) and, very likely, protein-mediated fusion of membranes. Ca(2+) also regulates the interaction between synaptotagmin (Syt) ... More
Pancreatic acinar cells express vesicle-associated membrane protein 2- and 8-specific populations of zymogen granules with distinct and overlapping roles in secretion.
AuthorsWeng N, Thomas DD, Groblewski GE
JournalJ Biol Chem
PubMed ID17272274
Previous studies have demonstrated roles for vesicle-associated membrane protein 2 (VAMP 2) and VAMP 8 in Ca(2+)-regulated pancreatic acinar cell secretion, however, their coordinated function in the secretory pathway has not been addressed. Here we provide evidence using immunofluorescence microscopy, cell fractionation, and SNARE protein interaction studies that acinar cells ... More
Existence of two parallel mechanisms for glucose uptake in heterotrophic plant cells.
AuthorsEtxeberria E, González P, Tomlinson P, Pozueta-Romero J
JournalJ Exp Bot
PubMed ID15911561
The implied existence of two mechanisms for glucose uptake into heterotrophic plant cells was investigated using the fluorescent glucose derivative 2-NBDG (2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose), two membrane impermeable fluorescent markers (3000 mol. wt. dextran-Texas Red (d-TR) and Alexa-488), hexose carrier and endocytic inhibitors (phloridzin and wortmannin-A, respectively), and fluorescent and confocal microscopy. Both ... More
Tuning PAK Activity to Rescue Abnormal Myelin Permeability in HNPP.
Authors
JournalPLoS Genet
PubMed ID27583434
Zebrafish oxytocin neurons drive nocifensive behavior via brainstem premotor targets.
Authors
JournalNat Neurosci
PubMed ID31358991
The tolerance to hypoxia is defined by a time-sensitive response of the gene regulatory network in sea urchin embryos.
Authors
JournalDevelopment
PubMed ID33795230
Origin and role of the cerebrospinal fluid bidirectional flow in the central canal.
Authors
JournalElife
PubMed ID31916933
Mechanical control of innate immune responses against viral infection revealed in a human lung alveolus chip.
Authors
JournalNat Commun
PubMed ID35396513
Gliotoxin-induced swelling of astrocytes hinders diffusion in brain extracellular space via formation of dead-space microdomains.
Authors
JournalGlia
PubMed ID24687699
A switch in pdgfrb+ cell-derived ECM composition prevents inhibitory scarring and promotes axon regeneration in the zebrafish spinal cord.
Authors
JournalDev Cell
PubMed ID33412105
A structural and genotypic scaffold underlying temporal integration.
Authors
JournalJ Neurosci
PubMed ID25995475
Genetic, cellular, and structural characterization of the membrane potential-dependent cell-penetrating peptide translocation pore.
Authors
JournalElife
PubMed ID34713805
LAP-like non-canonical autophagy and evolution of endocytic vacuoles in pancreatic acinar cells.