Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Microglia (3)
- Motoneuron (3)
- Mouse (3)
- CRAC channel (2)
- Ca2+ channel (2)
-
- Carotid body (2)
- Cation channel (2)
- Lymphocyte (2)
- Metabolism (2)
- Mitochondria (2)
- Nerve (2)
- Neuromuscular Junction (2)
- Plasticity (2)
- ALS (1)
- Accessory Proteins (1)
- Acetylcholine Receptor (1)
- Acidification (1)
- Action potential (1)
- Activation (1)
- Adults (1)
- Aging (1)
- Aldosterone/Pharmacology (1)
- Alleles (1)
- Alpha rhythm (1)
- Amiloride/Pharmacology (1)
- Amino acid transport system A (1)
- Amyotrophic Lateral Sclerosis (1)
- Analgesic (1)
- Animals (1)
- Anti-Inflammatory Agents (1)
- Publication Year
- Publication
- Publication Type
Articles 61 - 83 of 83
Full-Text Articles in Medical Neurobiology
Charge Screening By Internal Ph And Polyvalent Cations As A Mechanism For Activation, Inhibition, And Rundown Of Trpm7/Mic Channels, J. Ashot Kozak, Masayuki Matsushita, Angus C. Nairn, Michael D. Cahalan
Charge Screening By Internal Ph And Polyvalent Cations As A Mechanism For Activation, Inhibition, And Rundown Of Trpm7/Mic Channels, J. Ashot Kozak, Masayuki Matsushita, Angus C. Nairn, Michael D. Cahalan
Neuroscience, Cell Biology & Physiology Faculty Publications
The Mg2+-inhibited cation (MIC) current, believed to represent activity of TRPM7 channels, is found in lymphocytes and mast cells, cardiac and smooth muscle, and several other eukaryotic cell types. MIC current is activated during whole-cell dialysis with divalent-free internal solutions. Millimolar concentrations of intracellular Mg2+ (or other divalent metal cations) inhibit the channels in a voltage-independent manner. The nature of divalent inhibition and the mechanism of channel activation in an intact cell remain unknown. We show that the polyamines (spermine, spermidine, and putrescine) inhibit the MIC current, also in a voltage-independent manner, with a potency that parallels …
Resting Potential–Dependent Regulation Of The Voltage Sensitivity Of Sodium Channel Gating In Rat Skeletal Muscle In Vivo, Gregory N. Filatov, Martin J. Pinter, Mark M. Rich
Resting Potential–Dependent Regulation Of The Voltage Sensitivity Of Sodium Channel Gating In Rat Skeletal Muscle In Vivo, Gregory N. Filatov, Martin J. Pinter, Mark M. Rich
Neuroscience, Cell Biology & Physiology Faculty Publications
Normal muscle has a resting potential of −85 mV, but in a number of situations there is depolarization of the resting potential that alters excitability. To better understand the effect of resting potential on muscle excitability we attempted to accurately simulate excitability at both normal and depolarized resting potentials. To accurately simulate excitability we found that it was necessary to include a resting potential–dependent shift in the voltage dependence of sodium channel activation and fast inactivation. We recorded sodium currents from muscle fibers in vivo and found that prolonged changes in holding potential cause shifts in the voltage dependence of …
A Developmental Switch In The Response Of Drg Neurons To Ets Transcription Factor Signaling, Simon Hippenmeyer, Eline Vrieseling, Markus Sigrist, Thomas Portmann, Celia Laengle, David R. Ladle, Silvia Arber
A Developmental Switch In The Response Of Drg Neurons To Ets Transcription Factor Signaling, Simon Hippenmeyer, Eline Vrieseling, Markus Sigrist, Thomas Portmann, Celia Laengle, David R. Ladle, Silvia Arber
Neuroscience, Cell Biology & Physiology Faculty Publications
Two ETS transcription factors of the Pea3 subfamily are induced in subpopulations of dorsal root ganglion (DRG) sensory and spinal motor neurons by target-derived factors. Their expression controls late aspects of neuronal differentiation such as target invasion and branching. Here, we show that the late onset of ETS gene expression is an essential requirement for normal sensory neuron differentiation. We provide genetic evidence in the mouse that precocious ETS expression in DRG sensory neurons perturbs axonal projections, the acquisition of terminal differentiation markers, and their dependence on neurotrophic support. Together, our findings indicate that DRG sensory neurons exhibit a temporal …
Stim1, An Essential And Conserved Component Of Store-Operated Ca2+ Channel Function, Jack Roos, Paul J. Digregorio, Andriy V. Yeromin, Kari Ohlsen, Maria I. Lioudyno, Shenyuan L. Zhang, Olga Safrina, J. Ashot Kozak, Steven L. Wagner, Michael D. Cahalan, Gönül Veliçelebi, Kenneth A. Stauderman
Stim1, An Essential And Conserved Component Of Store-Operated Ca2+ Channel Function, Jack Roos, Paul J. Digregorio, Andriy V. Yeromin, Kari Ohlsen, Maria I. Lioudyno, Shenyuan L. Zhang, Olga Safrina, J. Ashot Kozak, Steven L. Wagner, Michael D. Cahalan, Gönül Veliçelebi, Kenneth A. Stauderman
Neuroscience, Cell Biology & Physiology Faculty Publications
Store-operated Ca2+ (SOC) channels regulate many cellular processes, but the underlying molecular components are not well defined. Using an RNA interference (RNAi)-based screen to identify genes that alter thapsigargin (TG)-dependent Ca2+ entry, we discovered a required and conserved role of Stim in SOC influx. RNAi-mediated knockdown of Stim in Drosophila S2 cells significantly reduced TG-dependent Ca2+ entry. Patch-clamp recording revealed nearly complete suppression of the Drosophila Ca2+ release-activated Ca2+(CRAC) current that has biophysical characteristics similar to CRAC current in human T cells. Similarly, knockdown of the human homologue STIM1 significantly reduced CRAC channel activity …
Distinct Properties Of Crac And Mic Channels In Rbl Cells, J. Ashot Kozak, Hubert H. Kerschbaum, Michael D. Cahalan
Distinct Properties Of Crac And Mic Channels In Rbl Cells, J. Ashot Kozak, Hubert H. Kerschbaum, Michael D. Cahalan
Neuroscience, Cell Biology & Physiology Faculty Publications
In rat basophilic leukemia (RBL) cells and Jurkat T cells, Ca2+ release–activated Ca2+ (CRAC) channels open in response to passive Ca2+ store depletion. Inwardly rectifying CRAC channels admit monovalent cations when external divalent ions are removed. Removal of internal Mg2+ exposes an outwardly rectifying current (Mg2+-inhibited cation [MIC]) that also admits monovalent cations when external divalent ions are removed. Here we demonstrate that CRAC and MIC currents are separable by ion selectivity and rectification properties: by kinetics of activation and susceptibility to run-down and by pharmacological sensitivity to external Mg2+, spermine, and …
Single Channel Properties And Regulated Expression Of Ca2+ Release-Activated Ca2+ (Crac) Channels In Human T Cells, Alla F. Fomina, Christopher M. Fanger, J. Ashot Kozak, Michael D. Cahalan
Single Channel Properties And Regulated Expression Of Ca2+ Release-Activated Ca2+ (Crac) Channels In Human T Cells, Alla F. Fomina, Christopher M. Fanger, J. Ashot Kozak, Michael D. Cahalan
Neuroscience, Cell Biology & Physiology Faculty Publications
Although the crucial role of Ca2+ influx in lymphocyte activation has been well documented, little is known about the properties or expression levels of Ca2+ channels in normal human T lymphocytes. The use of Na+ as the permeant ion in divalent-free solution permitted Ca2+ release-activated Ca2+ (CRAC) channel activation, kinetic properties, and functional expression levels to be investigated with single channel resolution in resting and phytohemagglutinin (PHA)-activated human T cells. Passive Ca2+ store depletion resulted in the opening of 41-pS CRAC channels characterized by high open probabilities, voltage-dependent block by extracellular Ca2+ in …
Staphylococcal Enterotoxin B Primes Cytokine Secretion And Lytic Activity In Response To Native Bacterial Antigens, K. M. Mason, T. D. Dryden, Nancy J. Bigley, P. S. Fink
Staphylococcal Enterotoxin B Primes Cytokine Secretion And Lytic Activity In Response To Native Bacterial Antigens, K. M. Mason, T. D. Dryden, Nancy J. Bigley, P. S. Fink
Neuroscience, Cell Biology & Physiology Faculty Publications
Superantigens stimulate T-lymphocyte proliferation and cytokine production, but the effects of superantigen exposure on cell function within a complex, highly regulated immune response remain to be determined. In this study, we demonstrate that superantigen exposure significantly alters the murine host response to bacterial antigens in an in vitro coculture system. Two days after exposure to the superantigen staphylococcal enterotoxin B, splenocytes cultured with Streptococcus mutans produced significantly greater amounts of gamma interferon (IFN-gamma) and interleukin-12 than did sham-injected controls. The majority of IFN-gamma production appeared to be CD8(+) T-cell derived since depletion of this cell type dramatically reduced the levels …
Identifying Swelling-Activated Channels From Ion Selectivity Patterns, Dan R. Halm
Identifying Swelling-Activated Channels From Ion Selectivity Patterns, Dan R. Halm
Neuroscience, Cell Biology & Physiology Faculty Publications
No abstract provided.
Direct Demonstration Of Retroviral Recombination In A Rhesus Monkey, Dawn P. Wooley, Randall A. Smith, Susan Czajak, Ronald C. Desrosiers
Direct Demonstration Of Retroviral Recombination In A Rhesus Monkey, Dawn P. Wooley, Randall A. Smith, Susan Czajak, Ronald C. Desrosiers
Neuroscience, Cell Biology & Physiology Faculty Publications
Recombination may be an important mechanism for increasing variation in retroviral populations. Retroviral recombination has been demonstrated in tissue culture systems by artificially creating doubly infected cells. Evidence for retroviral recombination in vivo is indirect and is based principally on the identification of apparently mosaic human immunodeficiency virus type 1 genomes from phylogenetic analyses of viral sequences. We infected a rhesus monkey with two different molecularly cloned strains of simian immunodeficiency virus. One strain of virus had a deletion in vpx and vpr, and the other strain had a deletion in nef. Each strain on its own induced low virus …
A Recombinant Inwardly Rectifying Potassium Channel Coupled To Gtp-Binding Proteins, Kim W. Chan, M. Noelle Langan, Jin Liang Sui, J. Ashot Kozak, Amanda Pabon, John A. A. Ladias, Diomedes E. Logothetis
A Recombinant Inwardly Rectifying Potassium Channel Coupled To Gtp-Binding Proteins, Kim W. Chan, M. Noelle Langan, Jin Liang Sui, J. Ashot Kozak, Amanda Pabon, John A. A. Ladias, Diomedes E. Logothetis
Neuroscience, Cell Biology & Physiology Faculty Publications
GTP-binding (G) proteins have been shown to mediate activation of inwardly rectifying potassium (K+) channels in cardiac, neuronal and neuroendocrine cells. Here, we report functional expression of a recombinant inwardly rectifying channel which we call KGP (or hpKir3.4), to signify that it is K+ selective, G-protein-gated and isolated from human pancreas. KGP expression in Xenopus oocytes resulted in sizeable basal (or agonist-independent) currents while coexpression with a G-protein-linked receptor, yielded additional agonist-induced currents. Coexpression of KGP and hGIRK1 (a human brain homolog of GIRK1/Kir3.1) produced much larger basal currents than those observed with KGP or hGIRK1 alone, and upon coexpression …
Effects Of Natural Sequence Variation On Recognition By Monoclonal Antibodies Neutralize Simian Immunodeficiency Virus Infectivity, Weon Sang Choi, Catherine Collignon, Clotilde Thiriart, Dawn P. Wooley, E. J. Scott, Karen A. Kent, Ronald C. Desrosiers
Effects Of Natural Sequence Variation On Recognition By Monoclonal Antibodies Neutralize Simian Immunodeficiency Virus Infectivity, Weon Sang Choi, Catherine Collignon, Clotilde Thiriart, Dawn P. Wooley, E. J. Scott, Karen A. Kent, Ronald C. Desrosiers
Neuroscience, Cell Biology & Physiology Faculty Publications
The determinants of immune recognition by five monoclonal antibodies (KK5, KK9, KK17, Senv7.1, and Senv101.1) that neutralize simian immunodeficiency virus infectivity were analyzed. These five neutralizing monoclonal antibodies were generated to native SIVmac251 envelope glycoprotein expressed by a vaccinia virus recombinant vector. All five recognize conformational or discontinuous epitopes and require native antigen for optimal recognition. These monoclonal antibodies also recognize SIVmac239 gp120, but they do not recognize gp120 of two natural variants of SIVmac239, 1-12 and 8-22, which evolved during the course of persistent infection in vivo (D.P.W. Burns and R.C. Desrosiers, J. Virol. 65:1843-1854, 1991). Recombinant viruses which …
High Rates Of Frameshift Mutations Within Homo-Oligomeric Runs During A Single Cycle Of Retroviral Replication, Dawn P. Wooley, H. M. Temin
High Rates Of Frameshift Mutations Within Homo-Oligomeric Runs During A Single Cycle Of Retroviral Replication, Dawn P. Wooley, H. M. Temin
Neuroscience, Cell Biology & Physiology Faculty Publications
Homo-oligomeric runs were inserted into a spleen necrosis virus-based retrovirus vector to determine the nature and rate of mutations within runs of 10 to 12 identical nucleotides during a single replication cycle. Clones of helper cells containing integrated copies of retroviral vectors were used to produce virus for infection of target (nonhelper) cells. Proviral sequences from target cell clones were compared with proviral sequences from helper cell clones to study mutations that occurred during a single cycle of replication. In addition to the internal region spanning the homo-oligomeric inserts, a naturally occurring run of 10 T's in the long terminal …
Simian Immunodeficiency Virus Mutants Resistant To Serum Neutralization Arise During Persistent Infection Of Rhesus Monkeys, Dawn P. Wooley, Catherine Collignon, Ronald C. Desrosiers
Simian Immunodeficiency Virus Mutants Resistant To Serum Neutralization Arise During Persistent Infection Of Rhesus Monkeys, Dawn P. Wooley, Catherine Collignon, Ronald C. Desrosiers
Neuroscience, Cell Biology & Physiology Faculty Publications
We previously described the pattern of sequence variation in gp120 following persistent infection of rhesus monkeys with the pathogenic simian immunodeficiency virus SIVmac239 molecular clone (D.P.W. Burns and R.C. Desrosiers, J. Virol. 65:1843, 1991). Sequence changes were confined largely to five variable regions (V1 to V5), four of which correspond to human immunodeficiency virus type 1 (HIV-1) gp120 variable regions. Remarkably, 182 of 186 nucleotide substitutions that were documented in these variable regions resulted in amino acid changes. This is an extremely nonrandom pattern, which suggests selective pressure driving amino acid changes in discrete variable domains. In the present study, …
Gelatinase Activity In The Mouse Uterus During Early Pregnancy, Carol A. Brenner, Richard R. Adler, Gary L. Nieder
Gelatinase Activity In The Mouse Uterus During Early Pregnancy, Carol A. Brenner, Richard R. Adler, Gary L. Nieder
Gary L. Nieder
No abstract provided.
Gelatinase Activity In The Mouse Uterus During Early Pregnancy, Carol A. Brenner, Richard R. Adler, Gary L. Nieder
Gelatinase Activity In The Mouse Uterus During Early Pregnancy, Carol A. Brenner, Richard R. Adler, Gary L. Nieder
Neuroscience, Cell Biology & Physiology Faculty Publications
No abstract provided.
Anion Permeation In An Apical Membrane Chloride Channel Of A Secretory Epithelial Cell, Dan R. Halm, Raymond A. Frizzell
Anion Permeation In An Apical Membrane Chloride Channel Of A Secretory Epithelial Cell, Dan R. Halm, Raymond A. Frizzell
Neuroscience, Cell Biology & Physiology Faculty Publications
Single channel currents though apical membrane Cl channels of the secretory epithelial cell line T84 were measured to determine the anionic selectivity and concentration dependence of permeation. The current-voltage relation was rectified with single channel conductance increasing at positive potentials. At 0 mV the single channel conductance was 41 ± 2 pS. Permeability, determined from reversal potentials, was optimal for anions with diameters between 0.4 and 0.5 nm. Anions of larger diameter had low permeability, consistent with a minimum pore diameter of 0.55 nm. Permeability for anions of similar size was largest for those ions with a more symmetrical charge …
Strain-Specific Neutralizing Determinant In The Transmembrane Protein Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Daniel P. Silva, Fulvia Dimarzo Veronese, Ronald C. Desrosiers
Strain-Specific Neutralizing Determinant In The Transmembrane Protein Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Daniel P. Silva, Fulvia Dimarzo Veronese, Ronald C. Desrosiers
Neuroscience, Cell Biology & Physiology Faculty Publications
Monoclonal antibody SF8/5E11, which recognizes the transmembrane protein (TMP) of simian immunodeficiency virus of macaque monkeys (SIVmac), displayed strict strain specificity. It reacted with cloned and uncloned SIVmac251 but not with cloned SIVmac142 and SIVmac239 on immunoblots. This monoclonal antibody neutralized infection by cloned, cell-free SIVmac251 and inhibited formation of syncytia by cloned SIVmac251-infected cells; these activities were specific to cloned SIVmac251 and did not occur with the other viruses. Site-specific mutagenesis was used to show that TMP amino acids 106 to 110 (Asp-Trp-Asn-Asn-Asp) determined the strain specificity of the monoclonal antibody. This strain-specific neutralizing determinant is located within a …
Selection Of Genetic Variants Of Simian Immunodeficiency Virus In Persistently Infected Rhesus Monkeys, Dawn P. Wooley, Ronald C. Desrosiers
Selection Of Genetic Variants Of Simian Immunodeficiency Virus In Persistently Infected Rhesus Monkeys, Dawn P. Wooley, Ronald C. Desrosiers
Neuroscience, Cell Biology & Physiology Faculty Publications
Genetic and antigenic variation may be one means by which lentiviruses that cause AIDS avoid elimination by host immune responses. Genetic variation in the envelope gene (env) was studied by comparing the nucleotide sequences of 27 clones obtained from two rhesus monkeys infected with molecularly cloned simian immunodeficiency virus. All 27 clones differed from each other and differed from the input clone in the gp120 (SU) portion of the envelope gene. Nucleotide substitutions were shown to accumulate with time at an average rate of 8.5 per 1,000 per year in SU. Surprisingly, the majority of nucleotide substitutions (81%) resulted in …
Significance Of Premature Stop Codons In Env Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Yathirajulu M. Naidu, Harry W. Kestler Iii, Muthiah D. Daniel, Yen Li, Ronald C. Desrosiers
Significance Of Premature Stop Codons In Env Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Yathirajulu M. Naidu, Harry W. Kestler Iii, Muthiah D. Daniel, Yen Li, Ronald C. Desrosiers
Neuroscience, Cell Biology & Physiology Faculty Publications
The location of the translational termination codon for the transmembrane protein (TMP) varies in three infectious molecular clones of simian immunodeficiency virus from macaques (SIVmac). The SIVmac251 and SIVmac142 infectious clones have premature stop signals that differ in location by one codon; transfection of these DNAs into human HUT-78 cells yielded virus with a truncated TMP (28 to 30 kilodaltons [kDa]). The SIVmac239 infectious clone does not have a premature stop codon in its TMP-coding region. Transfection of HUT-78 cells with this clone initially yielded virus with a full-length TMP (41 kDa). …
Aldosterone Stimulates K Secretion Across Mammalian Colon Independent Of Na Absorption, Gerhard Rechkemmer, Dan R. Halm
Aldosterone Stimulates K Secretion Across Mammalian Colon Independent Of Na Absorption, Gerhard Rechkemmer, Dan R. Halm
Neuroscience, Cell Biology & Physiology Faculty Publications
K transport across guinea pig (Cavia porcellus) distal colon was measured in vitro using isotopically determined unidirectional fluxes. Aldosterone stimulated electrogenic Na absorption, as measured by amiloride-sensitive short-circuit current (Isc), and reduced net K absorption from +2.5 ± 0.2 µEq/cm2 per hr to +0.8 ± 0.3 µEq/cm2 per hr (mean ± SEM). Amiloride addition to the mucosal solution did not enhance net K absorption, as expected if inhibiting active Na absorption would reduce active K secretion as in the distal nephron. The amiloride-insensitive Isc was -1.0 ± 0.2 µEq/cm2 per hr (mean ± SEM) …
Electrophysiology Of Flounder Intestinal Mucosa. I. Conductance Properties Ofthe Cellular And Paracellular Pathways, Dan R. Halm, Edward J. Krasny Jr., Raymond A. Frizzell
Electrophysiology Of Flounder Intestinal Mucosa. I. Conductance Properties Ofthe Cellular And Paracellular Pathways, Dan R. Halm, Edward J. Krasny Jr., Raymond A. Frizzell
Neuroscience, Cell Biology & Physiology Faculty Publications
We evaluated the conductances for ion flow across the cellular and paracellular pathways of flounder intestine using microelectrode techniques and ion-replacement studies. Apical membrane conductance properties are dominated by the presence of Ba-sensitive K channels. An elevated mucosal solution K concentration, [K]m, depolarized the apical membrane potential (ψa) and, at [K]m less than 40 mM, the K dependence of ψa was abolished by 1-2 mM mucosal Ba. The basolateral membrane displayed Cl conductance behavior, as evidenced by depolarization of the basolateral membrane potential (ψb) with reduced serosal Cl concentrations, [Cl]s. …
Electrophysiology Of Flounder Intestinal Mucosa. Ii. Relation Of The Electrical Potential Profile To Coupled Nacl Absorption, Dan R. Halm, Edward J. Krasny Jr., Raymond A. Frizzell
Electrophysiology Of Flounder Intestinal Mucosa. Ii. Relation Of The Electrical Potential Profile To Coupled Nacl Absorption, Dan R. Halm, Edward J. Krasny Jr., Raymond A. Frizzell
Neuroscience, Cell Biology & Physiology Faculty Publications
We characterized the hyperpolarization of the electrical potential profile of flounder intestinal cells that accompanies inhibition of NaCl cotransport. Several observations indicate that hyperpolarization of ψa and ψb (Δψa,b) results from inhibition of NaCl entry across the apical membrane: (a) the response was elicited by replacement of mucosal solution Cl or Na by nontransported ions, and (b) mucosal bumetanide or serosal cGMP, inhibitors of NaCl influx, elicited Δψa,b and decreased the transepithelial potential (ψt) in parallel. Regardless of initial values, ψa and ψb approached the equilibrium potential for K (EK …
Metabolism In Preimplantation Mouse Embryos, Harry M. Weitlauf, Gary L. Nieder
Metabolism In Preimplantation Mouse Embryos, Harry M. Weitlauf, Gary L. Nieder
Neuroscience, Cell Biology & Physiology Faculty Publications
The ability of preimplantation mouse embryos to utilize glucose oxidatively is controlled, in part at least, at the level of glycolysis. Various experimental observations are reviewed that indicate the regulatory mechanism in delayed implanting blastocysts involves the classic negative allosteric feedback of high levels of ATP on phosphofructokinase while the situation in 2-cell embryos appears to be more complicated. That is, in addition to the usual negative effect of ATP and citrate on phosphofructokinase, there appears to be a modification of hexokinase that prevents phosphorylation of adequate amounts of glucose and results in low levels of fructose-6-phosphate at the 2-cell …