Mechanism of collagen activation in human platelets.
AuthorsRoberts DE, McNicol A, Bose R
JournalJ Biol Chem
PubMed ID14981087
The mechanism of collagen-induced human platelet activation was examined using Ca2+, Na+, and the pH-sensitive fluorescent dyes calcium green/fura red, sodium-binding benzofuran isophthalate, and 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. Administration of a moderate dose of collagen (10 microg/ml) to human platelets resulted in an increase in [Ca2+](i) and platelet aggregation. The majority of this ... More
The molecular basis of differential subcellular localization of C2 domains of protein kinase C-alpha and group IVa cytosolic phospholipase A2.
AuthorsStahelin RV, Rafter JD, Das S, Cho W
JournalJ Biol Chem
PubMed ID12531893
'The C2 domain is a Ca(2+)-dependent membrane-targeting module found in many cellular proteins involved in signal transduction or membrane trafficking. C2 domains are unique among membrane targeting domains in that they show a wide range of lipid selectivity for the major components of cell membranes, including phosphatidylserine and phosphatidylcholine. To ... More
Differential regulation of nuclear and cytosolic Ca2+ in HeLa cells.
AuthorsBadminton MN, Campbell AK, Rembold CM
JournalJ Biol Chem
PubMed ID8940122
'The results reported in this study address the controversial issue that nuclear free Ca2+ ([Ca2+]n) may be regulated independently of cytosolic free Ca2+ ([Ca2+]c). We have measured [Ca2+]n and [Ca2+]c with recombinant aequorin targeted to the nucleus and cytosol in HeLa cells. We found that histamine, ATP, and ionomycin increased ... More
A single optical fiber fluorometric device for measurement of intracellular Ca2+ concentration: its application to hippocampal neurons in vitro and in vivo.
AuthorsKudo Y, Akita K, Nakamura T, Ogura A, Makino T, Tamagawa A, Ozaki K, Miyakawa A
JournalNeuroscience
PubMed ID1436506
'We developed a new system to measure the intracellular Ca2+ concentration in the deep region of the central nervous system with a single optical fiber (300 microns in diameter), used for both excitation and detection of the fluorescence of previously loaded fura-2. With this system, a brain region loaded with ... More
Protein and acidosis alter calcium-binding and fluorescence spectra of the calcium indicator indo-1.
AuthorsBaker AJ, Brandes R, Schreur JH, Camacho SA, Weiner MW
JournalBiophys J
PubMed ID7819496
'The fluorescent indicator indo-1 is widely used to monitor intracellular calcium concentration. However, quantitation is limited by uncertain effects of the intracellular environment on indicator properties. The goal of this study was to determine the effects of protein and acidosis on the fluorescence spectra and calcium dissociation constant (Kd) of ... More
Calcium sensing receptor activation by a calcimimetic suggests a link between cooperativity and intracellular calcium oscillations.
AuthorsMiedlich S, Gama L, Breitwieser GE
JournalJ Biol Chem
PubMed ID12399473
'Activation of the calcium sensing receptor (CaR) by small increments in extracellular calcium (Ca(2+)(e)) induces intracellular calcium (Ca(2+)(i)) oscillations that are dependent on thapsigargin-sensitive intracellular calcium stores. Phenylalkylamines such as NPS R-568 are allosteric modulators (calcimimetics) that activate CaR by increasing the apparent affinity of the receptor for calcium. We ... More
Changes in free calcium in the endoplasmic reticulum of living cells detected using targeted aequorin.
AuthorsKendall JM, Badminton MN, Dormer RL, Campbell AK
JournalAnal Biochem
PubMed ID7985790
'The Ca(2+)-activated photoprotein aequorin has been engineered with the endoplasmic reticulum (ER)-targeting sequence from calreticulin at the N-terminus and the KDEL sequence at the C-terminus so that it locates in the ER of living cells. Targeting of apoaequorin to the ER of COS7 cells was demonstrated by immunolocalization. Selective permeabilization ... More
Calcium regulates the association between mitochondria and a smooth subdomain of the endoplasmic reticulum.
AuthorsWang HJ, Guay G, Pogan L, Sauvé R, Nabi IR
JournalJ Cell Biol
PubMed ID10995452
'Association between the ER and mitochondria has long been observed, and the formation of close contacts between ER and mitochondria is necessary for the ER-mediated sequestration of cytosolic calcium by mitochondria. Autocrine motility factor receptor (AMF-R) is a marker for a smooth subdomain of the ER, shown here by confocal ... More
Calcium signaling mechanisms in dedifferentiated cardiac myocytes: comparison with neonatal and adult cardiomyocytes.
AuthorsPoindexter BJ, Smith JR, Buja LM, Bick RJ
JournalCell Calcium
PubMed ID11728132
'Our studies focused on calcium sparking and calcium transients in cultured adult rat cardiomyocytes and compared these findings to those in cultured neonatal and freshly isolated adult cardiomyocytes. Using deconvolution fluorescence microscopy and spec trophotometric image capture, sequence acquisitions were examined for calcium spark intensities, calcium concentrations and whether sparks ... More
Calmodulin-dependent regulation of inducible and neuronal nitric-oxide synthase.
AuthorsLee SJ, Stull JT
JournalJ Biol Chem
PubMed ID9765272
'Neuronal and endothelial nitric-oxide synthases depend upon Ca2+/calmodulin for activation, whereas the activity of the inducible nitric-oxide synthase is Ca2+-independent, presumably due to tightly bound calmodulin. To study these different mechanisms, a series of chimeras derived from neuronal and inducible nitric- oxide synthases were analyzed. Chimeras containing only the oxygenase ... More
A confocal scanning laser microscope for quantitative ratiometric 3D measurements of [Ca2+] and Ca2+ diffusions in living cells stained with Fura-2.
AuthorsHelm PJ, Franksson O, Carlsson K
JournalPflugers Arch
PubMed ID7792144
'A confocal scanning laser microscope (CSLM) for observation and quantitative ratiometric measurements of the intracellular dynamics of Ca2+ ions in living neurons has been developed. The instrument consists of a UV-enhanced CSLM, an optical arrangement providing simultaneous excitation at two wavelengths, an electronic arrangement for processing the simultaneous fluorescence response, ... More
'Cytosolic calcium ([Ca2+]i) is an important mediator of neuronal signal transduction, participating in diverse biochemical reactions that elicit changes in synaptic efficacy, metabolic rate, and gene transcription. Excessive [Ca2+]i also has been implicated as a cause of acute neuronal injury, although measurement of [Ca2+]i in living neurons by fluorescent calcium ... More
Calreticulin modulates cell adhesiveness via regulation of vinculin expression.
AuthorsOpas M, Szewczenko-Pawlikowski M, Jass GK, Mesaeli N, Michalak M
JournalJ Cell Biol
PubMed ID8991101
'Calreticulin is an ubiquitous and highly conserved high capacity Ca(2+)-binding protein that plays a major role in Ca2+ storage within the lumen of the ER. Here, using L fibroblast cell lines expressing different levels of calreticulin, we show that calreticulin plays a role in the control of cell adhesiveness via ... More
Autoinhibition of a calmodulin-dependent calcium pump involves a structure in the stalk that connects the transmembrane domain to the ATPase catalytic domain.
'The regulation of Ca(2+)-pumps is important for controlling [Ca(2+)] in the cytosol and organelles of all eukaryotes. Here, we report a genetic strategy to identify residues that function in autoinhibition of a novel calmodulin-activated Ca(2+)-pump with an N-terminal regulatory domain (isoform ACA2 from Arabidopsis). Mutant pumps with constitutive activity were ... More
Ryanodine receptor adaptation: control mechanism of Ca(2+)-induced Ca2+ release in heart.
AuthorsGyörke S, Fill M
JournalScience
PubMed ID8387229
'Adaptation of single cardiac ryanodine receptor (RyR) channels was demonstrated by application of the caged calcium ion (Ca2+) methodology. In contrast to conventional desensitization found in surface membrane ligand-gated channels, single cardiac RyR channels adapted to maintained Ca2+ stimuli, preserving their ability to respond to a second (larger) Ca2+ stimulus. ... More
Calcium-dependent neutrophil secretion: characterization and regulation by annexins.
AuthorsRosales JL, Ernst JD
JournalJ Immunol
PubMed ID9550422
'To gain direct access to the secretory machinery and study the regulation, mechanisms, and effectors of Ca2+-dependent neutrophil secretion, we developed an efficient and reproducible method of plasma membrane permeabilization using streptolysin O. We confirmed previous studies that permeabilized neutrophils secrete in response to calcium alone, but we also found ... More
Lead increases inositol 1,4,5-trisphosphate levels but does not interfere with calcium transients in primary rat astrocytes.
'Alteration of receptor-mediated signal transduction pathways by inorganic lead (Pb) has been postulated to contribute to the neurotoxicity of this environmental toxicant, some of these effects involving astrocytes. As Pb is known to mimic Ca2+ in various biological systems or alter Ca(2+)-mediated cellular processes, we analyzed the effect of Pb ... More
Lobe-dependent regulation of ryanodine receptor type 1 by calmodulin.
AuthorsXiong LW, Newman RA, Rodney GG, Thomas O, Zhang JZ, Persechini A, Shea MA, Hamilton SL
JournalJ Biol Chem
PubMed ID12185083
'Calmodulin activates the skeletal muscle Ca(2+) release channel RYR1 at nm Ca(2+) concentrations and inhibits the channel at microm Ca(2+) concentrations. Using a deletion mutant of calmodulin, we demonstrate that amino acids 2-8 are required for high affinity binding of calmodulin to RYR1 at both nm and microm Ca(2+) concentrations ... More
A practical guide to the preparation of Ca2+ buffers.
AuthorsBers DM, Patton CW, Nuccitelli R
JournalMethods Cell Biol
PubMed ID8201981
Autophosphorylation and ADP regulate the Ca2+-dependent interaction of recoverin with rhodopsin kinase.
AuthorsSatpaev DK, Chen CK, Scotti A, Simon MI, Hurley JB, Slepak VZ
JournalBiochemistry
PubMed ID9665733
Recoverin is a 23 kDa myristoylated Ca2+-binding protein that inhibits rhodopsin kinase. We have used surface plasmon resonance to investigate the influences of Ca2+, myristoylation, and adenine nucleotides on the recoverin-rhodopsin kinase interaction. Our analyses confirmed that Ca2+ is required for recoverin to bind RK. Myristoylation had little effect on ... More
Mechanism of presynaptic inhibition by neuropeptide Y at sympathetic nerve terminals.
AuthorsToth PT, Bindokas VP, Bleakman D, Colmers WF, Miller RJ
JournalNature
PubMed ID8394510
Calcium influx through voltage-sensitive Ca2+ channels is the normal physiological stimulus for the activity-dependent release of neurotransmitters at synaptic contacts. It has been postulated that presynaptic inhibition of transmitter release is due to a reduction in Ca2+ influx at the nerve terminal, which could result from the direct inhibition of ... More
Repetitive Ca2+ spikes in a unicellular green alga.
Cytosolic Ca2+ activity ([Ca2+]cy) and membrane potential were measured simultaneously in the unicellular green alga Eremosphaera viridis. Steady state [Ca2+]cy was about 160 nM. A 'light-off' stimulus induced a transient elevation of [Ca2+]cy ([Ca2+]cy spike) in parallel with a transient hyperpolarization of the plasma membrane. Caffeine and Sr2+, known to ... More
Calcium spiking in plant root hairs responding to Rhizobium nodulation signals.
AuthorsEhrhardt DW, Wais R, Long SR
JournalCell
PubMed ID8646776
SUMMARY: Rhizobium lipochitooligosaccharide signal molecules stimulate multiple responses in legume host plants, including changes in host gene expression, cell growth, and mitoses leading to root nodule development. The basis for signal transduction in the plant is not known. We examined cytoplasmic free calcium in host root hairs using calcium-sensitive reporter ... More
Low-frequency modulation sensors using nanosecond fluorophores.
AuthorsLakowicz JR, Castellano FN, Dattelbaum JD, Tolosa L, Rao G, Gryczynski I
JournalAnal Chem
PubMed ID9868909
We describe a new approach to fluorescence sensing based on a mixture of fluorophores, one of which is sensitive to the desired analyte. If a long-lifetime analyte-insensitive fluorophore is mixed with a short-lifetime analyte-sensitive fluorophore, the modulation of the emission at conveniently low frequencies becomes equal to the fractional fluorescence ... More
Fluorescent fiber-optic calcium sensor for physiological measurements.
AuthorsShortreed M, Kopelman R, Kuhn M, Hoyland B
JournalAnal Chem
PubMed ID8651501
A new optical sensor based on covalent immobilization of a newly synthesized calcium-selective, long-wavelength, fluorescent indicator has been constructed, with a response dynamic range optimal for physiological measurements. Immobilization occurs via photoinitiated copolymerization of the indicator with acrylamide on the distal end of a silanized 125 micrograms diameter multimode optical ... More
Differential involvement of phospholipase A2/arachidonic acid and phospholipase C/phosphoinositol pathways during cholecystokinin receptor activated Ca2+ oscillations in pancreatic acini.
AuthorsTsunoda Y, Owyang C
JournalBiochem Biophys Res Commun
PubMed ID7688962
In pancreatic acini, administration of the phospholipase C inhibitor, U-73122, abolished Ca2+ oscillations and amylase secretion induced by CCK but had much less effect on the action of CCK analog JMV-180. In contrast, the phospholipase A2 inhibitor, ONO-RS-082, inhibited both Ca2+ spikes and amylase secretion induced by JMV-180, but it ... More
Angiotensin II mediates a sustained rise in nuclear and cytoplasmic calcium via multiple receptor subtypes.
AuthorsMunzenmaier DH, Greene AS
JournalAm J Physiol
PubMed ID7653620
Alterations in nuclear calcium levels in response to angiotensin II (ANG II) may play an important role in the trophic actions of ANG II. This study utilized confocal microscopy and nuclear staining to test the hypothesis that both nuclear and cytoplasmic calcium levels are altered in response to ANG II ... More
Alteration of intracellular Ca2+ transients in COS-7 cells transfected with the cDNA encoding skeletal-muscle ryanodine receptor carrying a mutation associated with malignant hyperthermia.
AuthorsTreves S, Larini F, Menegazzi P, Steinberg TH, Koval M, Vilsen B, Andersen JP, Zorzato F
JournalBiochem J
PubMed ID8053891
Malignant hyperthermia (MH), an inherited neuromuscular disease triggered by halogenated inhalational anaesthetics and skeletal-muscle relaxants, appears to be due to an alteration of intracellular Ca2+ homoeostasis. MH occurs in 1 out of 20,000 anaesthetized adults and is characterized by hypermetabolism, skeletal-muscle rigidity and elevation in body temperature, which is frequently ... More
N-methyl-D-aspartate receptors expressed in a nonneuronal cell line mediate subunit-specific increases in free intracellular calcium.
AuthorsGrant ER, Bacskai BJ, Pleasure DE, Pritchett DB, Gallagher MJ, Kendrick SJ, Kricka LJ, Lynch DR
JournalJ Biol Chem
PubMed ID8995308
N-methyl-D-aspartate (NMDA) receptors can mediate cell death in neurons and in non-neuronal cells that express recombinant NMDA receptors. In neurons, increases in intracellular calcium correlate with NMDA receptor-mediated death, supporting a key role for loss of cellular calcium homeostasis in excitotoxic cell death. In the present study, free intracellular calcium ... More
Enhanced electron flux and reduced calmodulin dissociation may explain "calcium-independent" eNOS activation by phosphorylation.
AuthorsMcCabe TJ, Fulton D, Roman LJ, Sessa WC
JournalJ Biol Chem
PubMed ID10692402
Bovine endothelial nitric oxide synthase (eNOS) is phosphorylated directly by the protein kinase Akt at serine 1179. Mutation of this residue to the negatively charged aspartate (S1179D eNOS) increases nitric oxide (NO) production constitutively, in the absence of agonist challenge. Here, we examine the potential mechanism of how aspartate at ... More
Syk and Fyn are required by mouse megakaryocytes for the rise in intracellular calcium induced by a collagen-related peptide.
AuthorsMelford SK, Turner M, Briddon SJ, Tybulewicz VL, Watson SP
JournalJ Biol Chem
PubMed ID9346887
Stimulation of platelets by collagen leads to activation of a tyrosine kinase cascade resulting in secretion and aggregation. We have recently shown that this pathway involves rapid tyrosine phosphorylation of an Fc receptor gamma chain, which contains an immunoreceptor tyrosine-based activation motif (ITAM), enabling interaction with the tandem SH2 domains ... More
A study of the precision of confocal, ratiometric, Fura-2-based [Ca2+] measurements.
AuthorsHelm PJ, Patwardhan A, Manders EM
JournalCell Calcium
PubMed ID9481479
The precision with which quantitative confocal ratiometric Fura-2-based calcium measurements can be performed has been investigated. A standard confocal scanning laser microscope system has been modified so as to enable excitation with the 351 nm and 364 nm lines of the UV argon laser and simultaneous separation of the fluorescence ... More
Apocalmodulin and Ca2+ calmodulin-binding sites on the CaV1.2 channel.
AuthorsTang W, Halling DB, Black DJ, Pate P, Zhang JZ, Pedersen S, Altschuld RA, Hamilton SL
JournalBiophys J
PubMed ID12944271
The cardiac L-type voltage-dependent calcium channel is responsible for initiating excitation-contraction coupling. Three sequences (amino acids 1609-1628, 1627-1652, and 1665-1685, designated A, C, and IQ, respectively) of its alpha(1) subunit contribute to calmodulin (CaM) binding and Ca(2+)-dependent inactivation. Peptides matching the A, C, and IQ sequences all bind Ca(2+)CaM. Longer ... More
Identification of a ryanodine receptor in rat heart mitochondria.
AuthorsBeutner G, Sharma VK, Giovannucci DR, Yule DI, Sheu SS
JournalJ Biol Chem
PubMed ID11297554
Recent studies have shown that, in a wide variety of cells, mitochondria respond dynamically to physiological changes in cytosolic Ca(2+) concentrations ([Ca(2+)](c)). Mitochondrial Ca(2+) uptake occurs via a ruthenium red-sensitive calcium uniporter and a rapid mode of Ca(2+) uptake. Surprisingly, the molecular identity of these Ca(2+) transport proteins is still ... More
Cytoplasmic calcium transients due to single action potentials and voltage-clamp depolarizations in mouse pancreatic B-cells.
AuthorsRorsman P, Ammälä C, Berggren PO, Bokvist K, Larsson O
JournalEMBO J
PubMed ID1639061
Changes in the cytoplasmic free calcium concentration ([Ca2+]i) in pancreatic B-cells play an important role in the regulation of insulin secretion. We have recorded [Ca2+]i transients evoked by single action potentials and voltage-clamp Ca2+ currents in isolated B-cells by the combination of dual wavelength emission spectrofluorimetry and the patch-clamp technique. ... More
Localization of the cyclic ADP-ribose-dependent calcium signaling pathway in hepatocyte nucleus.
AuthorsKhoo KM, Han MK, Park JB, Chae SW, Kim UH, Lee HC, Bay BH, Chang CF
JournalJ Biol Chem
PubMed ID10818108
CD38 is a type II transmembrane glycoprotein found on both hematopoietic and non-hematopoietic cells. It is known for its involvement in the metabolism of cyclic ADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate, two nucleotides with calcium mobilizing activity independent of inositol trisphosphate. It is generally believed that CD38 is ... More
Calcium signaling in a narrow somatic submembrane shell during synaptic activity in cerebellar Purkinje neurons.
AuthorsEilers J, Callewaert G, Armstrong C, Konnerth A
JournalProc Natl Acad Sci U S A
PubMed ID7479766
Temporal and spatial changes in the intracellular Ca2+ concentration ([Ca2+]i) were examined in dendrites and somata of rat cerebellar Purkinje neurons by combining whole-cell patch-clamp recording and fast confocal laser-scanning microscopy. In cells loaded via the patch pipette with the high-affinity Ca2+ indicator Calcium Green-1 (Kd approximately 220 nM), a ... More
Molecular characterization of S100A1-S100B protein in retina and its activation mechanism of bovine photoreceptor guanylate cyclase.
AuthorsDuda T, Goraczniak RM, Sharma RK
JournalBiochemistry
PubMed ID8639567
In contrast to the membrane guanylate cyclases which are stimulated by extracellular ligands, rod outer segment membrane guanylate cyclase (ROS-GC) activity is modulated intracellularly by calcium in two ways: one, where it is inhibited, and the other, where it is stimulated. The former way is linked to the phototransduction, and ... More
Permeation of monovalent cations through the non-capacitative arachidonate-regulated Ca2+ channels in HEK293 cells. Comparison with endogenous store-operated channels.
AuthorsMignen O, Shuttleworth TJ
JournalJ Biol Chem
PubMed ID11285268
In a manner similar to voltage-gated Ca(2+) channels and Ca(2+) release-activated Ca(2+) (CRAC) channels, the recently identified arachidonate-regulated Ca(2+) (ARC) channels display a large monovalent conductance upon removal of external divalent cations. Using whole-cell patch-clamp recording, we have characterized the properties of these monovalent currents in HEK293 cells stably transfected ... More
Calcium influx factor, further evidence it is 5, 6-epoxyeicosatrienoic acid.
AuthorsRzigalinski BA, Willoughby KA, Hoffman SW, Falck JR, Ellis EF
JournalJ Biol Chem
PubMed ID9867827
We present evidence in astrocytes that 5,6-epoxyeicosatrienoic acid, a cytochrome P450 epoxygenase metabolite of arachidonic acid, may be a component of calcium influx factor, the elusive link between release of Ca2+ from intracellular stores and capacitative Ca2+ influx. Capacitative influx of extracellular Ca2+ was inhibited by blockade of the two ... More
Osteopontin gene regulation by oscillatory fluid flow via intracellular calcium mobilization and activation of mitogen-activated protein kinase in MC3T3-E1 osteoblasts.
Recently fluid flow has been shown to be a potent physical stimulus in the regulation of bone cell metabolism. However, most investigators have applied steady or pulsing flow profiles rather than oscillatory fluid flow, which occurs in vivo because of mechanical loading. Here oscillatory fluid flow was demonstrated to be ... More
Ca(2+)- and voltage-dependent gating of Ca(2+)- and ATP-sensitive cationic channels in brain capillary endothelium.
AuthorsCsanády L, Adam-Vizi V
JournalBiophys J
PubMed ID12829486
Biophysical properties of the Ca(2+)-activated nonselective cation channel expressed in brain capillaries were studied in inside-out patches from primary cultures of rat brain microvascular endothelial cells. At -40 mV membrane potential, open probability (P(o)) was activated by cytosolic [Ca(2+)] > 1 micro M and was half-maximal at approximately 20 micro ... More
Conformational changes and calcium binding by calretinin and its recombinant fragments containing different sets of EF hand motifs.
AuthorsKuznicki J, Strauss KI, Jacobowitz DM
JournalBiochemistry
PubMed ID7492538
Four recombinant fragments, representing different sets of EF-hand motifs of rat calretinin (CR) (I-II, I-III, III-VI, IV-VI), were prepared, and their Ca2+ -induced conformational changes were compared with those of full-length recombinant CR. All fragments were able to bind calcium ions as shown by 45Ca2+ overlay method on nitrocellulose and ... More
Nucleotide-regulated calcium signaling in lung fibroblasts and epithelial cells from normal and P2Y(2) receptor (-/-) mice.
AuthorsHomolya L, Watt WC, Lazarowski ER, Koller BH, Boucher RC
JournalJ Biol Chem
PubMed ID10473605
To test for the role of the P2Y(2) receptor (P2Y(2)-R) in the regulation of nucleotide-promoted Ca(2+) signaling in the lung, we generated P2Y(2)-R-deficient (P2Y(2)-R(-/-)) mice and measured intracellular Ca(2+)(i) responses (DeltaCa(2+)(i)) to nucleotides in cultured lung fibroblasts and nasal and tracheal epithelial cells from wild type and P2Y(2)-R(-/-) mice. In ... More
Amino acid mutagenesis of the ligand binding site and the dimer interface of the metabotropic glutamate receptor 1. Identification of crucial residues for setting the activated state.
AuthorsSato T, Shimada Y, Nagasawa N, Nakanishi S, Jingami H
JournalJ Biol Chem
PubMed ID12444084
Previously, we determined the crystal structures of the dimeric ligand binding region of the metabotropic glutamate receptor subtype 1. Each protomer binds l-glutamate within the crevice between the LB1 and LB2 domains. We proposed that the two different conformations of the dimer interface between the two LB1 domains define the ... More
Involvement of receptor cycling and receptor reserve in resensitization of muscarinic responses in SH-SY5Y human neuroblastoma cells.
AuthorsSzekeres PG, Koenig JA, Edwardson JM
JournalJ Neurochem
PubMed ID9523588
Preexposure of SH-SY5Y cells to the muscarinic agonist carbachol caused a rapid desensitization of subsequent carbachol-stimulated intracellular Ca2+ responses and a slower decrease in the number of receptors at the plasma membrane. Desensitization (to 30% of the control response) was maximal after 1 min of exposure to agonist, whereas the ... More
Ethidium bromide-induced inhibition of mitochondrial gene transcription suppresses glucose-stimulated insulin release in the mouse pancreatic beta-cell line betaHC9.
AuthorsHayakawa T, Noda M, Yasuda K, Yorifuji H, Taniguchi S, Miwa I, Sakura H, Terauchi Y, Hayashi J, Sharp GW, Kanazawa Y, Akanuma Y, Yazaki Y, Kadowaki T
JournalJ Biol Chem
PubMed ID9685380
Recently, a mitochondrial mutation was found to be associated with maternally inherited diabetes mellitus (Kadowaki, T., Kadowaki, H., Mori, Y., Tobe, K., Sakuta, R., Suzuki, Y., Tanabe, Y, Sakura, H., Awata, T., Goto, Y., Hayakawa, T., Matsuoka, K., Kawamori, R., Kamada, T., Horai, S., Nonaka, I., Hagura, R., Akanuma, Y., ... More
Calcium is not required for 5-lipoxygenase activity at high phosphatidyl choline vesicle concentrations.
AuthorsSkorey KI, Gresser MJ
JournalBiochemistry
PubMed ID9609696
5-Lipoxygenase (5-LO) catalyzes the formation of 5-hydroperoxy-eicosatetraenoic acid (5-HPETE) and leukotriene A4 (LTA4) from arachidonic acid. Following a rise in intracellular calcium, 5-LO translocates to a membrane where it reacts with arachidonic acid via an 18 kD protein (FLAP). In vitro studies using a vesicle system of phosphatidylcholine (PC) and ... More
Volume changes in single N1E-115 neuroblastoma cells measured with a fluorescent probe.
A non-invasive microspectrofluorimetric technique was used to investigate experimentally induced changes in cell water volume in single N1E-115 murine neuroblastoma cells, using calcein, a derivative of fluorescein, as a marker of the intracellular water compartment. The osmotic behavior of N1E-115 cells exposed to media of various osmolalities was studied. Exposure ... More
Rapid interaction of FRCRCFa with the cytosolic side of the cardiac sarcolemma Na(+)-Ca2+ exchanger blocks the ion transport without preventing the binding of either sodium or calcium.
AuthorsKhananshvili D, Baazov D, Weil-Maslansky E, Shaulov G, Mester B
JournalBiochemistry
PubMed ID8961960
Positively charged cyclic hexapeptide Phe-Arg-Cys-Arg-Cys-Phe-CONH2 (FRCRCFa) represents a group of conformationally constrained peptides that block the cardiac sarcolemma Na(+)-Ca2+ exchanger [Khananshvili et al. (1995b) J. Biol. Chem. 270, 16182-16188]. Here, we study the kinetic mechanisms of FRCRCFa-induced inhibition of Na(+)-Ca2+ exchange and its partial reaction, the Ca(2+)-Ca2+ exchange. The Nai-dependent ... More
Time-resolved monitoring of electrogenic Na+-Ca2+ exchange in the isolated cardiac sarcolemma vesicles by using a rapid-response fluorescent probe.
AuthorsBaazov D, Wang X, Khananshvili D
JournalBiochemistry
PubMed ID9931008
As a major Ca exit system in myocytes, the electrogenic Na+-Ca2+ exchange is exposed to rapid changes of regulatory factors (e.g., cytosolic Ca) during the excitation-contraction coupling. The dynamic aspects of the exchanger response to regulatory factors have not been resolved in the past due to technical limitations. Here, we ... More
Signal transduction in eclosion hormone-induced secretion of ecdysis-triggering hormone.
AuthorsKingan TG, Cardullo RA, Adams ME
JournalJ Biol Chem
PubMed ID11313360
Inka cells of insect epitracheal glands (EGs) secrete preecdysis and ecdysis-triggering hormones (PETH and ETH) at the end of each developmental stage. Both peptides act in the central nervous system to evoke the ecdysis behavioral sequence, a stereotype behavior during which old cuticle is shed. Secretion of ETH is stimulated ... More
Cross-talk of the receptors for bradykinin, serotonin, and ATP shown by single cell Ca2+ responses indicating different modes of Ca2+ activation in a neuroblastoma x glioma hybrid cell line.
AuthorsReetz G, Reiser G
JournalJ Neurochem
PubMed ID7906721
Modes of Ca2+ activation by bradykinin, serotonin, and ATP and the possible receptor cross-talk were investigated in mouse neuroblastoma x rat glioma hybrid cells (108CC15) by monitoring fura-2 fluorescence in single cells. A transient rise of cytosolic Ca2+ activity was induced by short pulses of the hormones. Brief exposure of ... More
Connexin-aequorin chimerae report cytoplasmic calcium environments along trafficking pathways leading to gap junction biogenesis in living COS-7 cells.
The cytoplasmic calcium environments along membrane trafficking pathways leading to gap junction intercellular communication channels at the plasma membrane were studied. Connexins, the constitutive proteins of gap junctions, were fused at their carboxyl terminus to the calcium-sensitive photoprotein aequorin. The cellular location of the chimeric proteins was determined by immunolocalization ... More
Kinetics of calcium release from manganese peroxidase during thermal inactivation.
AuthorsTimofeevski SL, Aust SD
JournalArch Biochem Biophys
PubMed ID9185626
It was previously reported that manganese peroxidase from the white-rot fungus Phanerochaete chrysosporium was susceptible to thermal inactivation because it contains relatively labile Ca2+ ions required for stability and activity [Sutherland and Aust (1996) Arch. Biochem. Biophys. 332, 128-134]. In this work we determined that four Ca2+ ions are present ... More
Lipoxin A4 stimulates a cytosolic Ca2+ increase in human bronchial epithelium.
AuthorsBonnans C, Mainprice B, Chanez P, Bousquet J, Urbach V
JournalJ Biol Chem
PubMed ID12500974
Lipoxins are biologically active eicosanoids possessing anti-inflammatory properties. Using a calcium imaging system we investigated the effect of lipoxin A(4) (LXA(4)) on intracellular [Ca(2+)] ([Ca(2+)](i)) of human bronchial epithelial cell. Exposure of the cells to LXA(4) produced a dose-dependent increase in [Ca(2+)](i) followed by a recovery to basal values in ... More
Peptide probe of ryanodine receptor function. Imperatoxin A, a peptide from the venom of the scorpion Pandinus imperator, selectively activates skeletal-type ryanodine receptor isoforms.
We have used [3H]ryanodine binding experiments and single channel recordings to provide convergent descriptions of the effect of imperatoxin A (IpTxa), a approximately 5-kDa peptide from the venom of the scorpion Pandinus imperator (Valdivia, H. H., Kirby, M. S., Lederer, W. J., and Coronado, R. (1992) Proc. Ntl. Acad. Sc. ... More
A turquoise fluorescence lifetime-based biosensor for quantitative imaging of intracellular calcium.
Authors
JournalNat Commun
PubMed ID34887382
The Nav1.9 channel is a key determinant of cold pain sensation and cold allodynia.
Authors
JournalCell Rep
PubMed ID25959819
Survival of Cancer Stem-Like Cells Under Metabolic Stress via CaMK2α-mediated Upregulation of Sarco/Endoplasmic Reticulum Calcium ATPase Expression.
Authors
JournalClin Cancer Res
PubMed ID29279319
Sensitive red protein calcium indicators for imaging neural activity.
Authors
JournalElife
PubMed ID27011354
Presynaptic Mitochondrial Volume and Packing Density Scale with Presynaptic Power Demand.
Authors
JournalJ Neurosci
PubMed ID34907026
Dantrolene Prevents the Lymphostasis Caused by Doxorubicin in the Rat Mesenteric Circulation.
Authors
JournalFront Pharmacol
PubMed ID34483938
Astrocytes as regulators of synaptic function: a quest for the Ca2+ master key.
Authors
JournalNeuroscientist
PubMed ID21536839
Absolute measurement of cellular activities using photochromic single-fluorophore biosensors and intermittent quantification.
Authors
JournalNat Commun
PubMed ID35387971
Calcium dependence of neurotransmitter release at a high fidelity synapse.