'Gap junctions, which are essential for functional coordination and homeostasis within tissues, permit the direct intercellular exchange of small molecules. The abundance and diversity of this exchange depends on the number and selectivity of the comprising channels and on the transjunctional gradient for and chemical character of the permeant molecules. ... More
Visualizing formation and dynamics of vacuoles in living cells using contrasting dextran-bound indicator: endocytic and nonendocytic vacuoles.
'Here we describe a technique that allows us to visualize in real time the formation and dynamics (fusion, changes of shape, and translocation) of vacuoles in living cells. The technique involves infusion of a dextran-bound fluorescent probe into the cytosol of the cell via a patch pipette, using the whole-cell ... More
Low pH inhibits compensatory endocytosis at a step between depolarization and calcium influx.
AuthorsSmith RM, Baibakov B, Lambert NA, Vogel SS
JournalTraffic
PubMed ID12010458
'Cell function can be modulated by the insertion and removal of ion channels from the cell surface. The mechanism used to keep channels quiescent prior to delivery to the cell surface is not known. In eggs, cortical vesicle exocytosis inserts voltage-gated calcium channels into the cell surface. Calcium influx through ... More
Multiple diffusion mechanisms due to nanostructuring in crowded environments.
AuthorsSanabria H, Kubota Y, Waxham MN
JournalBiophys J
PubMed ID17040979
'One of the key questions regarding intracellular diffusion is how the environment affects molecular mobility. Mostly, intracellular diffusion has been described as hindered, and the physical reasons for this behavior are: immobile barriers, molecular crowding, and binding interactions with immobile or mobile molecules. Using results from multi-photon fluorescence correlation spectroscopy, ... More
Receptor-dependent and -independent axonal retrograde transport of poliovirus in motor neurons.
AuthorsOhka S, Sakai M, Bohnert S, Igarashi H, Deinhardt K, Schiavo G, Nomoto A,
JournalJ Virol
PubMed ID19244317
'Poliovirus (PV), when injected intramuscularly into the calf, is incorporated into the sciatic nerve and causes an initial paralysis of the inoculated limb in transgenic (Tg) mice carrying the human PV receptor (hPVR/CD155) gene. We have previously demonstrated that a fast retrograde axonal transport process is required for PV dissemination ... More
Single-cell electroporation for gene transfer in vivo.
AuthorsHaas K, Sin WC, Javaherian A, Li Z, Cline HT
JournalNeuron
PubMed ID11301019
We report an electroporation technique for targeting gene transfer to individual cells in intact tissue. Electrical stimulation through a micropipette filled with DNA or other macromolecules electroporates a single cell at the tip of the micropipette. Electroporation of a plasmid encoding enhanced green fluorescent protein (GFP) into the brain of ... More
Active suppression of interneuron programs within developing motor neurons revealed by analysis of homeodomain factor HB9.
Sonic hedgehog (Shh) specifies the identity of both motor neurons (MNs) and interneurons with morphogen-like activity. Here, we present evidence that the homeodomain factor HB9 is critical for distinguishing MN and interneuron identity in the mouse. Presumptive MN progenitors and postmitotic MNs express HB9, whereas interneurons never express this factor. ... More
Hindered diffusion through an aqueous pore describes invariant dye selectivity of Cx43 junctions.
AuthorsHeyman NS, Burt JM,
JournalBiophys J
PubMed ID17921206
The permselectivity (permeance/conductance) of Cx43-comprised gap junctions is a variable parameter of junctional function. To ascertain whether this variability in junctional permselectivity is explained by heterogeneous charge or size selectivity of the comprising channels, the permeance of individual Cx43 gap junctions to combinations of two dyes differing in either size ... More
Selective release of molecules from Weibel-Palade bodies during a lingering kiss.
AuthorsBabich V, Meli A, Knipe L, Dempster JE, Skehel P, Hannah MJ, Carter T,
JournalBlood
PubMed ID18252862
Exocytosis of specialized endothelial cell secretory organelles, Weibel-Palade bodies (WPBs), is thought to play an important role in regulating hemostasis and intravascular inflammation. The major WPB core proteins are Von Willebrand factor (VWF) and its propolypeptide (Proregion), constituting more than 95% of the content. Although the composition of the WPBs ... More
Heterocellular contact at the myoendothelial junction influences gap junction organization.
AuthorsIsakson BE, Duling BR
JournalCirc Res
PubMed ID15961721
Heterocellular communication between vascular smooth muscle cells (VSMC) and endothelial cells (EC) at the myoendothelial junction (MEJ) is a critical part of control of the arteriolar wall. We have developed an in vitro model of the MEJ composed of primary cultures of murine EC and VSMC. Immunoctytochemistry and immunoblots demonstrated ... More
Membrane perturbation and fusion pore formation in influenza hemagglutinin-mediated membrane fusion. A new model for fusion.
AuthorsBonnafous P, Stegmann T
JournalJ Biol Chem
PubMed ID10692407
Low pH-induced fusion mediated by the hemagglutinin (HA) of influenza virus involves conformational changes in the protein that lead to the insertion of a "fusion peptide" domain of this protein into the target membrane and is thought to perturb the membrane, triggering fusion. By using whole virus, purified HA, or ... More
Rabies virus-induced membrane fusion pathway.
AuthorsGaudin Y
JournalJ Cell Biol
PubMed ID10931871
Fusion of rabies virus with membranes is triggered at low pH and is mediated by the viral glycoprotein (G). The rabies virus-induced fusion pathway was studied by investigating the effects of exogenous lipids having various dynamic molecular shapes on the fusion process. Inverted cone-shaped lysophosphatidylcholines (LPCs) blocked fusion at a ... More
Direct membrane retrieval into large vesicles after exocytosis in sea urchin eggs.
AuthorsWhalley T, Terasaki M, Cho MS, Vogel SS
JournalJ Cell Biol
PubMed ID8522582
At fertilization in sea urchin eggs, elevated cytosolic Ca2+ leads to the exocytosis of 15,000-18,000 1.3-microns-diam cortical secretory granules to form the fertilization envelope. Cortical granule exocytosis more than doubles the surface area of the egg. It is thought that much of the added membrane is retrieved by subsequent endocytosis. ... More
Calcium-regulated exocytosis is required for cell membrane resealing.
AuthorsBi GQ, Alderton JM, Steinhardt RA
JournalJ Cell Biol
PubMed ID8557742
Using confocal microscopy, we visualized exocytosis during membrane resealing in sea urchin eggs and embryos. Upon wounding by a laser beam, both eggs and embryos showed a rapid burst of localized Ca(2+)-regulated exocytosis. The rate of exocytosis was correlated quantitatively with successfully resealing. In embryos, whose activated surfaces must first ... More
Phrenic motoneuron morphology during rapid diaphragm muscle growth.
In the adult rat, there is a general correspondence between the sizes of motoneurons, motor units, and muscle fibers that has particular functional importance in motor control. During early postnatal development, after the establishment of singular innervation, there is rapid growth of diaphragm muscle (Dia(m)) fibers. In the present study, ... More
Optoinjection for efficient targeted delivery of a broad range of compounds and macromolecules into diverse cell types.
AuthorsClark IB, Hanania EG, Stevens J, Gallina M, Fieck A, Brandes R, Palsson BO, Koller MR
JournalJ Biomed Opt
PubMed ID16526911
Efficient delivery of compounds and macromolecules into living cells is essential in many fields including basic research, applied drug discovery, and clinical gene therapy. Unfortunately, current delivery methods, such as cationic lipids and electroporation, are limited by the types of macromolecules and cells that can be employed, poor efficiency, and/or ... More
Hindered diffusion of high molecular weight compounds in brain extracellular microenvironment measured with integrative optical imaging.
AuthorsNicholson C, Tao L
JournalBiophys J
PubMed ID7508761
This paper describes the theory of an integrative optical imaging system and its application to the analysis of the diffusion of 3-, 10-, 40-, and 70-kDa fluorescent dextran molecules in agarose gel and brain extracellular microenvironment. The method uses a precisely defined source of fluorescent molecules pressure ejected from a ... More
Influenza-virus-liposome lipid mixing is leaky and largely insensitive to the material properties of the target membrane.
AuthorsShangguan T, Alford D, Bentz J
JournalBiochemistry
PubMed ID8664288
Monolayer intrinsic curvature, void stabilization, and membrane rupture tension have been suggested as important factors determining the rate of membrane fusion. Here, we have studied the kinetics of fusion between influenza virus and target liposomes as a function of various target membrane material properties. In order to examine the fusion ... More
Spinal cholinergic interneurons differentially control motoneuron excitability and alter the locomotor network operational range.
Authors
JournalSci Rep
PubMed ID29386582
Smooth muscle Ca(2+) -activated and voltage-gated K+ channels modulate conducted dilation in rat isolated small mesenteric arteries.
Authors
JournalMicrocirculation
PubMed ID21535295
Live-cell epigenome manipulation by synthetic histone acetylation catalyst system.
Authors
JournalProc Natl Acad Sci U S A
PubMed ID33468653
Different functions of two putative Drosophila α2δ subunits in the same identified motoneurons.
Authors
JournalSci Rep
PubMed ID32792569
Complementary expression of calcium binding proteins delineates the functional organization of the locomotor network.
Authors
JournalBrain Struct Funct
PubMed ID29423637
Competition between histone and transcription factor binding regulates the onset of transcription in zebrafish embryos.
Authors
JournalElife
PubMed ID28425915
ATP and large signaling metabolites flux through caspase-activated Pannexin 1 channels.
Authors
JournalElife
PubMed ID33410749
Small Molecule Enhancers of Endosome-to-Cytosol Import Augment Anti-tumor Immunity.
Authors
JournalCell Rep
PubMed ID32668257
Adult spinal motoneurons change their neurotransmitter phenotype to control locomotion.
Authors
JournalProc Natl Acad Sci U S A
PubMed ID30275331
Astrocyte plasticity in mice ensures continued endfoot coverage of cerebral blood vessels following injury and declines with age.