Alpha-adducin dissociates from F-actin and spectrin during platelet activation.
AuthorsBarkalow KL, Italiano JE, Chou DE, Matsuoka Y, Bennett V, Hartwig JH
JournalJ Cell Biol
PubMed ID12743105
'Aspectrin-based skeleton uniformly underlies and supports the plasma membrane of the resting platelet, but remodels and centralizes in the activated platelet. alpha-Adducin, a phosphoprotein that forms a ternary complex with F-actin and spectrin, is dephosphorylated and mostly bound to spectrin in the membrane skeleton of the resting platelet at sites ... More
The platelet cytoskeleton regulates the affinity of the integrin alpha(IIb)beta(3) for fibrinogen.
AuthorsBennett JS, Zigmond S, Vilaire G, Cunningham ME, Bednar B
JournalJ Biol Chem
PubMed ID10464255
'Agonist-generated inside-out signals enable the platelet integrin alpha(IIb)beta(3) to bind soluble ligands such as fibrinogen. We found that inhibiting actin polymerization in unstimulated platelets with cytochalasin D or latrunculin A mimics the effects of platelet agonists by inducing fibrinogen binding to alpha(IIb)beta(3). By contrast, stabilizing actin filaments with jasplakinolide prevented ... More
Feedback inhibition of sodium/calcium exchange by mitochondrial calcium accumulation.
AuthorsOpuni K, Reeves JP
JournalJ Biol Chem
PubMed ID10801871
'Chinese hamster ovary cells expressing the bovine cardiac Na(+)/Ca(2+) exchanger were subjected to two periods of 5 and 3 min, respectively, during which the extracellular Na(+) concentration ([Na(+)](o)) was reduced to 20 mm; these intervals were separated by a 5-min recovery period at 140 mm Na(+)(o). The cytosolic Ca(2+) concentration ... More
Early cellular events couple covalent binding of reactive metabolites to cell killing by nephrotoxic cysteine conjugates.
AuthorsChen Q, Jones TW, Stevens JL
JournalJ Cell Physiol
PubMed ID7525611
'Addition of the nephrotoxic cysteine conjugate, S-(1,2-dichlorovinyl)-L-cysteine (DCVC), to the LLC-PK1 line of renal epithelial cells leads to covalent binding of reactive intermediates followed by thiol depletion, lipid peroxidation, and cell death (Chen et al., 1990, J. Biol. Chem., 265:21603-21611). The present study was designed to determine if increased intracellular ... More
Cell type-specific modes of feedback regulation of capacitative calcium entry.
AuthorsLouzao MC, Ribeiro CM, Bird GS, Putney JW
JournalJ Biol Chem
PubMed ID8662975
'The Ca2+-ATPase inhibitor, thapsigargin, activated Ca2+ entry into pancreatic acinar cells, a process known as capacitative calcium entry. In cells loaded with the calcium chelator BAPTA, the transient Ca2+ release was blunted and the rise of [Ca2+]i on readdition of Ca2+ was slowed. However, the steady-state [Ca2+]i due to Ca2+ ... More
Picomolar platelet-activating factor mobilizes Ca to change platelet shape without activating phospholipase C or protein kinase C; simultaneous fluorometric measurement of intracellular free Ca concentration and aggregation.
AuthorsJames-Kracke MR, Sexe RB, Shukla SD
JournalJ Pharmacol Exp Ther
PubMed ID7965802
'The purpose of this study was to investigate signal transduction mechanisms activated by low and high concentrations of platelet-activating factor (PAF) in rabbit platelets and to contrast the responses to those induced by thrombin. We measured changes in intracellular free calcium ([Ca++]i) with fura2, while monitoring light scatter simultaneously as ... More
Novel modulatory effect of L-type calcium channels at newly formed neuromuscular junctions.
AuthorsSugiura Y, Ko CP
JournalJ Neurosci
PubMed ID8994064
'This study aimed to examine changes of presynaptic voltage-sensitive calcium channel (VSCC) subtypes during synapse formation and regeneration in relation to transmitter release at the neuromuscular junction (NMJ). Synaptic potentials were recorded from developing rat NMJs and from regenerating mouse and frog NMJs. As in normal adult NMJs, evoked transmitter ... More
The relationship between depletion of intracellular Ca2+ stores and activation of Ca2+ current by muscarinic receptors in neuroblastoma cells.
AuthorsMathes C, Thompson SH
JournalJ Gen Physiol
PubMed ID8648300
'The relationship between the depletion of IP3-releasable intracellular Ca2+ stores and the activation of Ca(2+)-selective membrane current was determined during the stimulation of M1 muscarinic receptors in N1E-115 neuroblastoma cells. External Ca2+ is required for refilling Ca2+ stores and the voltage-independent, receptor-regulated Ca2+ current represents a significant Ca2+ source for ... More
Dependence of the Ca2+-inhibitable adenylyl cyclase of C6-2B glioma cells on capacitative Ca2+ entry.
AuthorsFagan KA, Mons N, Cooper DM
JournalJ Biol Chem
PubMed ID9535924
'The ability of adenylyl cyclases to be regulated by physiological transitions in Ca2+ provides a key point for integration of cytosolic Ca2+ concentration ([Ca2+]i) and cAMP signaling. Ca2+-sensitive adenylyl cyclases, whether endogenously or heterologously expressed, require Ca2+ entry for their regulation, rather than Ca2+ release from intracellular stores (Chiono, M., ... More
Effect of Bcl-2 on oxidant-induced cell death and intracellular Ca2+ mobilization.
AuthorsIchimiya M, Chang SH, Liu H, Berezesky IK, Trump BF, Amstad PA
JournalAm J Physiol
PubMed ID9730968
'The mechanism by which Bcl-2 inhibits cell death is unknown. It has been suggested that Bcl-2 functions as an antioxidant. Because Bcl-2 is localized mainly to the membranes of the endoplasmic reticulum (ER) and the mitochondria, which represent the main intracellular storage sites for Ca2+, we hypothesized that Bcl-2 might ... More
Evidence against a major role for Ca2+ in hypoxia-induced gene expression in human hepatoma cells (Hep3B).
AuthorsMetzen E, Fandrey J, Jelkmann W
JournalJ Physiol
PubMed ID10358107
'1. The human hepatoma cell line Hep3B is a widely used model for studies of hypoxia-related gene expression. Cytosolic free calcium concentration ([Ca2+]i) has been implicated in cellular oxygen-sensing processes. We investigated whether calcium ions have a significant impact on the production of erythropoietin (EPO) and vascular endothelial growth factor ... More
Functional colocalization of calcium and calcium-gated potassium channels in control of transmitter release.
'We examined, using physiological and morphological techniques, the distribution of Ca(2+)-gated K+ (gKca) channels relative to the location of Ca2+ channels and transmitter release sites at the frog neuromuscular junction (NM). Charybdotoxin (ChTx) and iberiotoxin, blockers of gKca channels with large conductances, increase transmitter release at the frog NMJ. Intracellular ... More
Presynaptic strontium dynamics and synaptic transmission.
AuthorsXu-Friedman MA, Regehr WG
JournalBiophys J
PubMed ID10096899
'Strontium can replace calcium in triggering neurotransmitter release, although peak release is reduced and the duration of release is prolonged. Strontium has therefore become useful in probing release, but its mechanism of action is not well understood. Here we study the action of strontium at the granule cell to Purkinje ... More
Dynamics of intracellular free Mg2+ changes in a vascular smooth muscle cell line.
AuthorsQuamme GA, Dai LJ, Rabkin SW
JournalAm J Physiol
PubMed ID8342644
'Intracellular free Mg2+ concentration ([Mg2+]i) has been implicated in the pathogenesis of hypertension. It has been postulated that Mg2+ through its antagonistic effects on intracellular Ca2+ concentration may affect tension and contractility of vascular smooth muscle cells. An established cell line of rat thoracic aorta cells (A10) was cultured on ... More
Spontaneous acetylcholine release in mammalian neuromuscular junctions.
AuthorsLosavio A, Muchnik S
JournalAm J Physiol
PubMed ID9435487
'Spontaneous secretion of the neurotransmitter acetylcholine in mammalian neuromuscular synapsis depends on the Ca2+ content of nerve terminals. The Ca2+ electrochemical gradient favors the entry of this cation. We investigated the possible involvement of three voltage-dependent Ca2+ channels (VDCC) (L-, N-, and P/Q-types) on spontaneous transmitter, release at the rat ... More
'Agrin is an extracellular matrix protein that directs neuromuscular junction formation. Early signal transduction events in agrin-mediated postsynaptic differentiation include activation of a receptor tyrosine kinase and phosphorylation of acetylcholine receptors (AChRs), but later steps in this pathway are unknown. Here, we have investigated the role of intracellular calcium in ... More
Characterizing the site and mode of action of dynorphin at hippocampal mossy fiber synapses in the guinea pig.
AuthorsCastillo PE, Salin PA, Weisskopf MG, Nicoll RA
JournalJ Neurosci
PubMed ID8815876
'Extracellular field potential recordings from the CA3 region in guinea pig hippocampal slices were used to study the release and action of dynorphin at the mossy fiber synapse. Dynorphin A(1-17) or U69593 inhibited mossy fiber synaptic responses in preparations in which the CA3 region was surgically isolated from the rest ... More
Critical upstream signals of cytochrome C release induced by a novel Bcl-2 inhibitor.
AuthorsAn J, Chen Y, Huang Z
JournalJ Biol Chem
PubMed ID14966123
'Cytochrome c release is a central step in the apoptosis induced by many death stimuli. Bcl-2 plays a critical role in controlling this step. In this study, we investigated the upstream mechanism of cytochrome c release induced by ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA14-1), a recently discovered small molecule inhibitor of Bcl-2. HA14-1 ... More
Intracellular hydrolysis of EGTA-esters.
AuthorsJuhász A, Eliás G, Kerékgyártó J, Kövér A
JournalActa Physiol Hung
PubMed ID3931418
'It has been established that the hydrolysis of EGTA-acetoxymethylester (AME) by red blood cells is about the tenth of the hydrolysis of acetylthiocholine (Ac-S-Ch). This splitting of AME could be inhibited by about 50% by prostigmine at a concentration of 0.75 X 10(-5) mol/l, while the splitting of Ac-S-Ch was ... More
Contributions of residual calcium to fast synaptic transmission.
AuthorsChen C, Regehr WG
JournalJ Neurosci
PubMed ID10414955
'Fast neurotransmitter release is driven by high calcium (10-100 microM) near open channels (Ca(local)), followed by a much smaller (<1 microM), longer-lasting residual calcium (Ca(res)). The most prominent component of release, phasic release, lasts several milliseconds and is thought to be triggered by Ca(local). A transient tail of release then ... More
Local positive feedback by calcium in the propagation of intracellular calcium waves.
AuthorsWang SS, Thompson SH
JournalBiophys J
PubMed ID8580312
'In many types of eukaryotic cells, the activation of surface receptors leads to the production of inositol 1,4,5-trisphosphate and calcium release from intracellular stores. Calcium release can occur in complex spatial patterns, including waves of release that traverse the cytoplasm. Fluorescence video microscopy was used to view calcium waves in ... More
Apoptosis in an interleukin-2-dependent cytotoxic T lymphocyte cell line is associated with intracellular acidification. Role of the Na(+)/H(+)-antiport.
AuthorsLi J, Eastman A
JournalJ Biol Chem
PubMed ID7852405
'Apoptosis is a form of cell death associated with DNA fragmentation and chromatin condensation. We recently established that intracellular acidification occurred during apoptosis following cytotoxic insult. The current studies were designed to determine whether intracellular acidification was more generally associated with apoptosis, specifically in a model of growth factor withdrawal. ... More
Signal transduction in monocytes and granulocytes measured by multiparameter flow cytometry.
AuthorsLund-Johansen F, Olweus J
JournalCytometry
PubMed ID1451600
'The novel calcium indicator fura red and the oxidative burst indicator dihydrorhodamine (both excited at 488 nm) were used in combination with multiparameter flow cytometry to allow simultaneous kinetic measurements of calcium fluxes and oxidative bursts in monocytes and granulocytes. Using this method it was possible to obtain direct evidence ... More
AuthorsLiu H, Miller E, van de Water B, Stevens JL
JournalJ Biol Chem
PubMed ID9582315
'Oxidants are important human toxicants. Increased intracellular free Ca2+ may be critical for oxidant toxicity, but this mechanism remains controversial. Furthermore, oxidants damage the endoplasmic reticulum (ER) and release ER Ca2+, but the role of the ER in oxidant toxicity and Ca2+ regulation during toxicity is also unclear. tert-Butylhydroperoxide (TBHP), ... More
Visualizing postendocytic traffic of synaptic vesicles at hippocampal synapses.
AuthorsLi Z, Murthy VN
JournalNeuron
PubMed ID11545718
'We have investigated mechanisms in postendocytic processing of synaptic vesicles at hippocampal synapses, using synaptobrevin/vesicle-associated membrane protein (VAMP) tagged with variants of the green fluorescent protein. Following exocytosis, VAMP is retrieved at synaptic and adjoining axonal regions. Retrieved VAMP-containing vesicles return to synaptic vesicle clusters at a rate slower than ... More
The response of renal tubular epithelial cells to physiologically and chemically induced growth arrest.
AuthorsJeong JK, Huang Q, Lau SS, Monks TJ
JournalJ Biol Chem
PubMed ID9054455
'Cells respond to a variety of stresses by activating the transcription of a battery of "acute phase" or "stress response" genes. The nature of this response is tailored to the nature of the stress. The extent to which physiologically and pathophysiologically induced growth arrest share common genomic responses is unclear. ... More
Overexpression of potassium channel RNA: in vivo development rescues neurons from suppression of morphological differentiation in vitro.
AuthorsJones SM, Hofmann AD, Lieber JL, Ribera AB
JournalJ Neurosci
PubMed ID7722635
'Neuronal differentiation often proceeds differently in vitro than it does in vivo. Previous work demonstrated that overexpression of potassium channel RNA reduces the number of morphologically identifiable neurons that appear in cultures prepared from neural plate stage (17-1/2 hr) embryos (Jones and Ribera, 1994). Here, we report that morphological differentiation ... More
SV2A and SV2B function as redundant Ca2+ regulators in neurotransmitter release.
AuthorsJanz R, Goda Y, Geppert M, Missler M, Südhof TC
JournalNeuron
PubMed ID10624962
'SV2 proteins are abundant synaptic vesicle proteins expressed in two major (SV2A and SV2B) and one minor isoform (SV2C) that resemble transporter proteins. We now show that SV2B knockout mice are phenotypically normal while SV2A- and SV2A/SV2B double knockout mice exhibit severe seizures and die postnatally. In electrophysiological recordings from ... More
Intracellular calcium chelators and oxidant-induced renal proximal tubule cell death.
AuthorsSchnellmann RG
JournalJ Biochem Toxicol
PubMed ID1774771
'The effect of intracellular calcium chelators on rabbit renal proximal tubule (RPT) cell death induced by t-butyl hydroperoxide (TBHP) and H2O2 was examined. Preincubation of RPT suspensions with 50 microM QUIN 2/AM completely prevented TBHP (0.5 mM) and H2O2 (2 mM) induced cell death [i.e., release of lactate dehydrogenase (LDH)]. ... More
Distinct short-term plasticity at two excitatory synapses in the hippocampus.
AuthorsSalin PA, Scanziani M, Malenka RC, Nicoll RA
JournalProc Natl Acad Sci U S A
PubMed ID8917586
'A single mossy fiber input contains several release sites and is located on the proximal portion of the apical dendrite of CA3 neurons. It is, therefore, well suited to exert a strong influence on pyramidal cell excitability. Accordingly, the mossy fiber synapse has been referred to as a detonator or ... More
Differential modulation of synaptic transmission by calcium chelators in young and aged hippocampal CA1 neurons: evidence for altered calcium homeostasis in aging.
AuthorsOuanounou A, Zhang L, Charlton MP, Carlen PL
JournalJ Neurosci
PubMed ID9920654
'The effects of membrane-permeant Ca2+ chelators on field EPSPs (fEPSPs) were measured in the hippocampal CA1 region of brain slices from young (2-4 months) and old (24-27 months) Fischer 344 rats. BAPTA-AM depressed fEPSPs in young slices by up to 70% but enhanced fEPSPs by 30% in aged slices. EGTA-AM, ... More
A practical guide to the preparation of Ca2+ buffers.
AuthorsBers DM, Patton CW, Nuccitelli R
JournalMethods Cell Biol
PubMed ID8201981
Critical evaluation of cytosolic calcium determination in resting muscle fibres from normal and dystrophic (mdx) mice.
AuthorsGailly P, Boland B, Himpens B, Casteels R, Gillis JM
JournalCell Calcium
PubMed ID8358771
The fluorescent probe Fura-2/AM was used to determine cytosolic free calcium concentration in soleus muscle and in isolated flexor digitorum brevis fibres. This required a precise calibration; therefore, each calibration parameter was studied in situ. The influence of the dye concentration on calcium measurements was also examined. This precise calibration ... More
Calcium-independent cytoskeleton disassembly induced by BAPTA.
AuthorsSaoudi Y, Rousseau B, Doussière J, Charrasse S, Gauthier-Rouvière C, Morin N, Sautet-Laugier C, Denarier E, Scaïfe R, Mioskowski C, Job D,
JournalEur J Biochem
PubMed ID15265045
In living organisms, Ca2+ signalling is central to cell physiology. The Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) has been widely used as a probe to test the role of calcium in a large variety of cell functions. Here we show that in most cell types BAPTA has a potent actin and ... More
Inhibition of cAMP accumulation by intracellular calcium mobilization in C6-2B cells stably transfected with substance K receptor cDNA.
AuthorsDeBernardi MA, Seki T, Brooker G
JournalProc Natl Acad Sci U S A
PubMed ID1718001
C6-2B rat glioma cells were stably transfected with substance K receptor cDNA and used to study interactions between cAMP and Ca2+ signaling pathways. Activation of the newly expressed receptors by substance K increased the intracellular free Ca2+ concentration, as monitored by single-cell fura-2 imaging, and markedly inhibited agonist- stimulated cAMP ... More
Involvement of intracellular Ca2+ in oxidant-induced NF-kappa B activation.
AuthorsSen CK, Roy S, Packer L
JournalFEBS Lett
PubMed ID8641467
In human Jurkat T cells and its subclone Wurzburg cells oxidant challenge elevated [Ca2+]i by mobilizing Ca2+ from intracellular stores. In Jurkat cells this effect was rapid and transient, but in Wurzburg cells the response was slow and sustained. H2O2-induced NF-kappaB activation in Wurzburg cells was not influenced by the ... More
P/Q-type calcium channels activate neighboring calcium-dependent potassium channels in mouse motor nerve terminals.
AuthorsProtti DA, Uchitel OD
JournalPflugers Arch
PubMed ID9211806
The identity of the voltage-dependent calcium channels (VDCC), which trigger the Ca2+-gated K+ currents (IK(Ca)) in mammalian motor nerve terminals, was investigated by means of perineurial recordings. The effects of Ca2+ chelators with different binding kinetics on the activation of IK(Ca) were also examined. The calcium channel blockers of the ... More
H-ras transfection of the rat kidney cell line NRK-52E results in increased induction of c-fos, c-jun and hsp70 following sulofenur treatment.
The effect of the antineoplastic drug sulofenur on the induction of the immediate-early genes (IEG) c-fos and c-jun and the stress gene hsp70 was compared in the rat kidney epithelial-like cell line NRK-52E and a derivative H-ras-transfected (H/1.2NRK-52E) cell line. Fold induction for each gene after sulofenur (500 microM) treatment ... More
A fluorescence technique to distinguish attached from ingested erythrocytes and zymosan particles in phagocytosing macrophages.
AuthorsGreenberg S, el Khoury J, Kaplan E, Silverstein SC
JournalJ Immunol Methods
PubMed ID2040809
While investigating the role of [Ca2+]i in Fc receptor-mediated phagocytosis, we found that clamping the [Ca2+]i to low levels by a variety of methods often led to increased plasma membrane permeability, rendering the hypotonic lysis method for calculating the phagocytosis index unreliable. To overcome this difficulty we developed a method ... More
Effects of BAPTA on force and Ca2+ transient during isometric contraction of frog muscle fibers.
AuthorsSun Y, Caputo C, Edman KA
JournalAm J Physiol
PubMed ID9688591
The effects of 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) on force and intracellular Ca2+ transient were studied during isometric twitches and tetanuses in single frog muscle fibers. BAPTA was added to the bathing solution in its permeant AM form (50 and 100 microM). There was no clear correlation between the changes in force ... More
Fusion of endosomes involved in synaptic vesicle recycling.
AuthorsHolroyd C, Kistner U, Annaert W, Jahn R
JournalMol Biol Cell
PubMed ID10473644
Recycling of vesicles of the regulated secretory pathway presumably involves passage through an early endosomal compartment as an intermediate step. To learn more about the involvement of endosomes in the recycling of synaptic and secretory vesicles we studied in vitro fusion of early endosomes derived from pheochromocytoma (PC12) cells. Fusion ... More
The role of intraorganellar Ca(2+) in late endosome-lysosome heterotypic fusion and in the reformation of lysosomes from hybrid organelles.
We have investigated the requirement for Ca(2+) in the fusion and content mixing of rat hepatocyte late endosomes and lysosomes in a cell-free system. Fusion to form hybrid organelles was inhibited by 1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA), but not by EGTA, and this inhibition was reversed by adding additional Ca(2+). Fusion ... More
Threshold calcium levels for lamellar body exocytosis in type II pneumocytes.
AuthorsHaller T, Auktor K, Frick M, Mair N, Dietl P
JournalAm J Physiol
PubMed ID10564173
Pulmonary surfactant is secreted via exocytosis of lamellar bodies (LBs) by alveolar type II cells. Here we analyzed the dependence of LB exocytosis on intracellular Ca(2+) concentration ([Ca(2+)](i)). In fura 2-loaded cells, [Ca(2+)](i) was selectively elevated by flash photolysis of a cell-permeant caged Ca(2+) compound (o-nitrophenyl EGTA-AM) or by gradually ... More
Mitochondria to nucleus stress signaling: a distinctive mechanism of NFkappaB/Rel activation through calcineurin-mediated inactivation of IkappaBbeta.
AuthorsBiswas G, Anandatheerthavarada HK, Zaidi M, Avadhani NG
JournalJ Cell Biol
PubMed ID12732617
Mitochondrial genetic and metabolic stress causes activation of calcineurin (Cn), NFAT, ATF2, and NFkappaB/Rel factors, which collectively alter the expression of an array of nuclear genes. We demonstrate here that mitochondrial stress-induced activation of NFkappaB/Rel factors involves inactivation of IkappaBbeta through Cn-mediated dephosphorylation. Phosphorylated IkappaBbeta is a substrate for Cn ... More
Mechanisms governing dendritic gamma-aminobutyric acid (GABA) release in the rat olfactory bulb.
AuthorsIsaacson JS
JournalProc Natl Acad Sci U S A
PubMed ID11120892
In the olfactory bulb, synaptic transmission between dendrites plays an important role in the processing of olfactory information. Glutamate released from the dendrites of principal mitral cells excites the dendritic spines of granule cells, which in turn release gamma-aminobutyric acid (GABA) back onto mitral cell dendrites. Slow N-methyl-d-aspartate (NMDA) receptors ... More
Role of Na+/Ca2+ exchanger in preventing Na+ overload and hepatocyte injury: opposite effects of extracellular and intracellular Ca2+ chelation.
AuthorsCarini R, de Cesaris MG, Bellomo G, Albano E
JournalBiochem Biophys Res Commun
PubMed ID9125111
We have previously shown that an increase of intracellular Na+ occurs in isolated rat hepatocytes undergoing ATP depletion and that Na+ accumulation is associated with an uncontrolled influx of Ca2+ through the activation in reverse mode of the Na+/Ca2+ exchanger. In the present study we have investigated the relationship between ... More
Involvement of intracellular calcium in morphine tolerance in mice.
AuthorsSmith FL, Dombrowski DS, Dewey WL
JournalPharmacol Biochem Behav
PubMed ID9972707
Opioid analgesic tolerance is associated with a disruption in Ca++ homeostasis. Drugs reducing Ca++ influx can prevent and reverse tolerance. The hypothesis was tested that both Ca++ influx and mobilization from intracellular pools maintains the expression of morphine tolerance. Ca++ modulating drugs were injected ICV at doses not affecting morphine's ... More
The intraacrosomal calcium pool plays a direct role in acrosomal exocytosis.
AuthorsDe Blas G, Michaut M, Treviño CL, Tomes CN, Yunes R, Darszon A, Mayorga LS
JournalJ Biol Chem
PubMed ID12379648
The acrosome reaction is a unique type of regulated exocytosis. The single secretory granule of the sperm fuses at multiple points with the overlying plasma membrane. In the past few years we have characterized several aspects of this process using streptolysin O-permeabilized human spermatozoa. Here we show that Rab3A triggers ... More
Mechanisms of cold-induced platelet actin assembly.
AuthorsHoffmeister KM, Falet H, Toker A, Barkalow KL, Stossel TP, Hartwig JH
JournalJ Biol Chem
PubMed ID11328807
Various agonists but also chilling cause blood platelets to increase cytosolic calcium, polymerize actin, and change shape. We report that cold increases barbed end nucleation sites in octyl glucoside-permeabilized platelets by 3-fold, enabling analysis of the intermediates of this response. Although chilling does not change polyphosphoinositide (ppI) levels, a ppI-binding ... More
L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals.
AuthorsUrbano FJ, Uchitel OD
JournalPflugers Arch
PubMed ID10089564
The involvement of the different types of voltage-dependent calcium channels (VDCC) in both DM-BAPTA-AM-incubated and EGTA-AM-incubated mature mice levator auris neuromuscular junctions (NMJ) was studied. We evaluated the effects of omega-agatoxin IVA (omega-Aga IVA), nitrendipine and omega-conotoxin GVIA (omega-CgTX) (P/Q-, L- and N-type VDCC blockers, respectively) on perineurial calcium currents ... More
The relationship between intracellular Ca2+ and the mitochondrial membrane potential in isolated proximal tubular cells from rat kidney exposed to the nephrotoxin 1,2-dichlorovinyl-cysteine.
Authorsvan de Water B, Zoetewey JP, de Bont HJ, Mulder GJ, Nagelkerke JF
JournalBiochem Pharmacol
PubMed ID8517866
The effects of 1,2-dichlorovinyl-cysteine (DCVC) on the intracellular free calcium concentration ([Ca2+]i) and the mitochondrial membrane potential (delta phi) were investigated in freshly isolated rat kidney proximal tubular cells (PTC). Prior to cell death, DCVC induced a rise in [Ca2+]i and a decrease in the delta phi. Omission of extracellular ... More
Modulation of Ca2+ transients and tension by intracellular EGTA in intact frog muscle fibers.
AuthorsJohnson JD, Jiang Y, Flynn M
JournalAm J Physiol
PubMed ID9176132
Ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) was used as an intracellular Ca2+ chelator to shorten the duration of the Ca2+ transient and to determine the rate-limiting steps in relaxation of frog skeletal muscle at 10 and 20 degrees C. Incubation with the acetoxymethyl ester of EGTA (EGTA-AM) produced a linear approximately ... More
Activity-dependent depression of GABAergic IPSCs in cultured hippocampal neurons.
AuthorsJensen K, Lambert JD, Jensen MS
JournalJ Neurophysiol
PubMed ID10400933
Short-term depression of monosynaptic GABAergic inhibitory postsynaptic currents (IPSCs) evoked between pairs of cultured rat hippocampal neurons was investigated using dual whole cell patch-clamp recordings. Paired stimuli applied to the GABAergic neuron resulted in paired-pulse depression (PPD) of the second IPSC (IPSC2) at interpulse intervals from 25 to 2,000 ms. ... More
UV-treated lipoproteins as a model system for the study of the biological effects of lipid peroxides on cultured cells. 4. Calcium is involved in the cytotoxicity of UV-treated LDL on lymphoid cell lines.
AuthorsNègre-Salvayre A, Salvayre R
JournalBiochim Biophys Acta
PubMed ID1739749
In lymphoid cells pulsed with 'cytotoxic' concentrations of UV-treated LDL, the study of the variations of free cytosolic calcium concentration, of the influence of extracellular calcium and of the protective effect of calcium chelators suggests that both intra- and extracellular calcium could play a major role in the genesis of ... More
Synergistic adhesive interactions and signaling mechanisms operating between platelet glycoprotein Ib/IX and integrin alpha IIbbeta 3. Studies in human platelets ans transfected Chinese hamster ovary cells.
AuthorsYap CL, Hughan SC, Cranmer SL, Nesbitt WS, Rooney MM, Giuliano S, Kulkarni S, Dopheide SM, Yuan Y, Salem HH, Jackson SP
JournalJ Biol Chem
PubMed ID10967111
This study investigates three aspects of the adhesive interaction operating between platelet glycoprotein Ib/IX and integrin alpha(IIb)beta(3). These include the following: 1) examining the sufficiency of GPIb/IX and integrin alpha(IIb)beta(3) to mediate irreversible cell adhesion on immobilized von Willebrand factor (vWf) under flow; 2) the ability of the vWf-GPIb interaction ... More
Delayed release of neurotransmitter from cerebellar granule cells.
AuthorsAtluri PP, Regehr WG
JournalJ Neurosci
PubMed ID9763467
At fast chemical synapses the rapid release of neurotransmitter that occurs within a few milliseconds of an action potential is followed by a more sustained elevation of release probability, known as delayed release. Here we characterize the role of calcium in delayed release and test the hypothesis that facilitation and ... More
Calcium-dependent paired-pulse facilitation of miniature EPSC frequency accompanies depression of EPSCs at hippocampal synapses in culture.
AuthorsCummings DD, Wilcox KS, Dichter MA
JournalJ Neurosci
PubMed ID8757244
Two forms of evoked neurotransmitter release at excitatory synapses between cultured hippocampal neurons have been described. After an action potential, it has been shown that transmitter initially is released synchronously, and this is followed by a period of "slow" asynchronous release. The "fast" synchronous component of release at these synapses ... More
Regulation of calreticulin gene expression by calcium.
AuthorsWaser M, Mesaeli N, Spencer C, Michalak M
JournalJ Cell Biol
PubMed ID9245785
We have isolated and characterized a 12-kb mouse genomic DNA fragment containing the entire calreticulin gene and 2.14 kb of the promoter region. The mouse calreticulin gene consists of nine exons and eight introns, and it spans 4.2 kb of genomic DNA. A 1.8-kb fragment of the calreticulin promoter was ... More
The enterotoxin of Bacteroides fragilis is a metalloprotease.
During the past decade, strains of Bacteroides fragilis that produce an enterotoxin have been implicated in diarrheal disease in animals and humans. The extracellular enterotoxin has been purified and characterized as a single polypeptide (M(r), approximately 20,000). Single specific primer-PCR was used to clone a portion of the B. fragilis ... More
Differences in the calcium-mediated regulation of gap junctional intercellular communication between a cell line consisting of initiated cells and a carcinoma-derived cell line.
AuthorsJansen LA, de Vrije T, Jongen WM
JournalCarcinogenesis
PubMed ID8968043
Differences in calcium-mediated regulation of gap junctional intercellular communication (GJIC) between a cell line consisting of mouse epidermal initiated cells (3PC) and a mouse epidermal carcinoma-derived cell line (CA3/7) were studied. Under low extracellular calcium ((Ca2+)e) conditions (0.05 mM) CA3/7 cells showed a low level of GJIC compared with 3PC ... More
Role of mitochondrial Ca2+ in the oxidative stress-induced dissipation of the mitochondrial membrane potential. Studies in isolated proximal tubular cells using the nephrotoxin 1,2-dichlorovinyl-L-cysteine.
Authorsvan de Water B, Zoeteweij JP, de Bont HJ, Mulder GJ, Nagelkerke JF
JournalJ Biol Chem
PubMed ID8182062
The relationship between mitochondrial Ca2+, oxidative stress, and a dissipation of the mitochondrial membrane potential (delta psi) was investigated in proximal tubular kidney cells. Freshly isolated proximal tubular cells from rat kidney were exposed to the nephrotoxin 1,2-dichlorovinyl-L-cysteine (DCVC). DCVC stimulated the formation of hydroperoxides as determined by flow cytometry ... More
Influence of CA2+ on K+ efflux during regulatory volume decrease in cultured astrocytes.
AuthorsQuesada O, Ordaz B, Morales-Mulia S, Pasantes-Morales H
JournalJ Neurosci Res
PubMed ID10412026
The calcium (Ca2+) dependence of potassium (K+) efflux activated by hyposmolarity in cultured cerebellar astrocytes was investigated, measuring in parallel experiments (86)Rb release and changes in cytosolic Ca2+ ([Ca2+]i). Hyposmotic (50%) medium increased [Ca2+]i from 117 to 386 nM, with contributions of extracellular Ca2+ and Ca2+ from the endoplasmic reticulum. ... More
Mudpuppy parasympathetic cardiac neurons exhibit spontaneous miniature outward currents (SMOCs) that are thought to be due to the activation of clusters of large conductance Ca(2+)-activated K(+) channels (BK channels) by localized release of Ca(2+) from internal stores close to the plasma membrane. Perforated-patch whole cell recordings were used to determine ... More
Characterization of a renal epithelial cell model of apoptosis using okadaic acid and the NRK-52E cell line.
AuthorsDavis MA, Smith MW, Chang SH, Trump BF
JournalToxicol Pathol
PubMed ID7732277
Apoptotic cell death plays an important role in the pathogenesis of renal tubular epithelial damage and repair following tubular injury. Presently, the cellular factors involved in regulating apoptotic pathways in the kidney are unknown. To address the possibility that protein phosphorylation may regulate apoptosis in kidney cells, okadaic acid (OKA), ... More
Cooling and freezing damage platelet membrane integrity.
AuthorsReid TJ, LaRussa VF, Esteban G, Clear M, Davies L, Shea S, Gorogias M
JournalCryobiology
PubMed ID10328911
Cytoskeletal rearrangements and a membrane lipid phase transition (liquid crystalline to gel) occur in platelets on cooling from 23 to 4 degrees C. A consequence of these structural alterations is irreversible cellular damage. We investigated whether platelet membrane integrity could be preserved by (a) previously studied combinations of a calcium ... More
Properties of neuroprotective cell-permeant Ca2+ chelators: effects on [Ca2+]i and glutamate neurotoxicity in vitro.
AuthorsTymianski M, Charlton MP, Carlen PL, Tator CH
JournalJ Neurophysiol
PubMed ID7823112
1. Cell-permeant Ca2+ chelators such as 1,2-bis-(2-amino-phenoxy)ethane- N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM) protect neurons against excitotoxic and ischemic neuronal injury in vitro and in vivo. Here we provide the first steps toward characterizing the mechanisms by which these agents produce their neuroprotective effects. 2. Cultured mouse spinal neurons were simultaneously ... More
Presynaptic calcium dynamics at the frog retinotectal synapse.
AuthorsFeller MB, Delaney KR, Tank DW
JournalJ Neurophysiol
PubMed ID8836232
1. We characterized the kinetics of presynaptic Ca2+ ion concentration in optic nerve fibers and terminals of the optic tectum in Rana pipiens with the use of microfluorimetry. Isolated frog brains were incubated with the membrane-permeant tetraacetoxymethyl ester (AM) of the Ca2+ indicator fura-2. An optic nerve shock caused a ... More
Sr2+-dependent asynchronous evoked transmission at rat striatal inhibitory synapses in vitro.
AuthorsRumpel E, Behrends JC
JournalJ Physiol
PubMed ID9852326
1. At striatal inhibitory synapses in cell culture, replacement of extracellular Ca2+ with Sr2+ desynchronized inhibitory postynaptic currents (IPSCs), reducing their peak amplitude and producing a succession of late, asynchronous synaptic events (late release). In the averaged IPSC waveform this resulted in an increase in both the fast and the ... More
Fast calcium removal during single twitches in amphibian skeletal muscle fibres.
AuthorsCaputo C, Bolaños P, Escobar AL
JournalJ Muscle Res Cell Motil
PubMed ID10555074
Fluorescence signals from the calcium sensitive dyes Fluo-3 or Rhod-2 were obtained simultaneously with isometric tension in single fibres isolated from the anterior tibialis muscle of Leptodactylus insularis (20-22 degrees C). Fluo-3 fluorescence signals were transformed into [Ca2+]i transients as previously described. Most of the decay phase of single twitch ... More
The von Willebrand factor-glycoprotein Ib/V/IX interaction induces actin polymerization and cytoskeletal reorganization in rolling platelets and glycoprotein Ib/V/IX-transfected cells.
AuthorsYuan Y, Kulkarni S, Ulsemer P, Cranmer SL, Yap CL, Nesbitt WS, Harper I, Mistry N, Dopheide SM, Hughan SC, Williamson D, de la Salle C, Salem HH, Lanza F, Jackson SP
JournalJ Biol Chem
PubMed ID10593912
Platelet adhesion to sites of vascular injury is initiated by the binding of the platelet glycoprotein (GP) Ib-V-IX complex to matrix-bound von Willebrand factor (vWf). This receptor-ligand interaction is characterized by a rapid on-off rate that enables efficient platelet tethering and rolling under conditions of rapid blood flow. We demonstrate ... More
Mechanisms of platelet-derived growth factor-induced arachidonic acid release in Swiss 3T3 fibroblasts: the role of a localized increase in free Ca2+ concentration beneath the plasma membrane and the activation of protein kinase C.
AuthorsChow SC, Powis G
JournalBiochim Biophys Acta
PubMed ID8399354
Stimulation of Swiss 3T3 fibroblasts with platelet-derived growth factor (PDGF) results in a transient increase in intracellular free Ca2+ concentration ([Ca2+]i) and a phospholipase A2 (PLA2)-dependent release of arachidonic acid (AA) of 500% over control values. In the absence of extracellular Ca2+, both the PDGF-induced transient increase in [Ca2+]i and ... More
Accumulation and extrusion of permeant Ca2+ chelators in attenuation of synaptic transmission at hippocampal CA1 neurons.
AuthorsOuanounou A, Zhang L, Tymianski M, Charlton MP, Wallace MC, Carlen PL
JournalNeuroscience
PubMed ID8923526
The effects of extracellularly applied membrane-permeant Ca2+ chelators on field excitatory postsynaptic potentials were determined in the hippocampal CA1 region of rat brain slices. Field excitatory postsynaptic potentials in slices perfused with 0.05-50 microM bis-(-O-aminophenoxy)-ethane-N,N,N,N,-tetraacetic acid acetoxymethyl (BAPTA-AM) for 15 min were reversibly attenuated by 10-45% in a concentration-dependent manner. ... More
Thapsigargin-induced calcium influx in the absence of detectable tyrosine phosphorylation in human platelets.
AuthorsVostal JG, Shafer B
JournalJ Biol Chem
PubMed ID8702645
Tyrosine phosphorylation is a potential mechanism for mediating store-operated calcium (SOC) influx in platelets and other nonexcitable cells. Thapsigargin induces calcium-dependent tyrosine phosphorylation and SOC influx in platelets. We prevented thapsigargin-induced tyrosine phosphorylation by buffering cytosolic calcium rise with the calcium chelator 1, 2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetomethoxyester (BAPTA-AM). Calcium influx, induced by ... More
In vivo and in vitro detachment of proximal tubular cells and F-actin damage: consequences for renal function.
AuthorsVan de Water B, Jaspers JJ, Maasdam DH, Mulder GJ, Nagelkerke JF
JournalAm J Physiol
PubMed ID7977793
We investigated the relationship between F-actin damage and cell detachment using nephrotoxic L-cysteine S-conjugates. In vivo S-(1,2-dichlorovinyl)-L-cysteine (DCVC) induced loss of F-actin in the S3 segment of the proximal tubule in the outer stripe of the outer medulla, which was associated with loss of the brush border and loss of ... More
Local subplasma membrane Ca2+ signals detected by a tethered Ca2+ sensor.
AuthorsLee MY, Song H, Nakai J, Ohkura M, Kotlikoff MI, Kinsey SP, Golovina VA, Blaustein MP
JournalProc Natl Acad Sci U S A
PubMed ID16924099
Accumulating evidence indicates that plasma membrane (PM) microdomains and the subjacent "junctional" sarcoplasmic/endoplasmic reticulum (jS/ER) constitute specialized Ca(2+) signaling complexes in many cell types. We examined the possibility that some Ca(2+) signals arising in the junctional space between the PM and jS/ER may represent cross-talk between the PM and jS/ER. ... More
Post-tetanic potentiation of GABAergic IPSCs in cultured rat hippocampal neurones.
AuthorsJensen K, Jensen MS, Lambert JD
JournalJ Physiol
PubMed ID10432340
1. Dual whole-cell patch-clamp recording was used to investigate post-tetanic potentiation (PTP) of GABAergic IPSCs evoked between pairs of cultured rat hippocampal neurones. Tetanization of the presynaptic neurone at frequencies (f) ranging from 5 to 100 Hz resulted in PTP of the IPSCs. Maximum PTP had a magnitude of 51.6 ... More
Activity and calcium-dependent mechanisms maintain reliable interneuron synaptic transmission in a rhythmic neural network.
AuthorsParker D
JournalJ Neurosci
PubMed ID10684877
Inputs from glutamatergic excitatory interneurons (EIN) to motor neurons in the lamprey spinal cord locomotor network exhibit activity-dependent depression during spike trains. The mechanism underlying this depression has been examined here, and its relevance to transmitter release during rhythmic activity has been investigated. The depression of EIN inputs was greater ... More
Endoplasmic reticulum chaperones GRP78 and calreticulin prevent oxidative stress, Ca2+ disturbances, and cell death in renal epithelial cells.
AuthorsLiu H, Bowes RC, van de Water B, Sillence C, Nagelkerke JF, Stevens JL
JournalJ Biol Chem
PubMed ID9268304
Activation of stress response genes can impart cellular tolerance to environmental stress. Iodoacetamide (IDAM) is an alkylating toxicant that up-regulates expression of hsp70 (Liu, H., Lightfoot, D. L., and Stevens, J. L. (1996) J. Biol. Chem. 271, 4805-4812) and grp78 in LLC-PK1 renal epithelial cells. Therefore, we used IDAM to ... More
Thapsigargin modulates agonist-stimulated cyclic AMP responses through cytosolic calcium-dependent and -independent mechanisms in rat pinealocytes.
AuthorsHo AK, Ogiwara T, Chik CL
JournalMol Pharmacol
PubMed ID8649350
The role of mobilization of intracellular Ca2+ in the adrenergic-stimulated cAMP accumulation in rat pinealocytes was investigated with thapsigargin, an agent that inhibits endoplasmic reticulum Ca2+-ATPase. It was found that although thapsigargin alone had no effect on the basal cAMP accumulation, it potentiated the beta-adrenergic-stimulated cAMP response by isoproterenol in ... More
Activation of heat shock factor by alkylating agents is triggered by glutathione depletion and oxidation of protein thiols.
AuthorsLiu H, Lightfoot R, Stevens JL
JournalJ Biol Chem
PubMed ID8617749
Transcriptional activation of heat shock protein genes is a common response to proteotoxic stress. Many drugs and chemicals that form reactive electrophiles modify protein structure by binding covalently to nucleophilic functional groups. Although many of these agents also activate transcription of the inducible member of the hsp70 gene family, it ... More
Ca(2+)-independent F-actin assembly and disassembly during Fc receptor-mediated phagocytosis in mouse macrophages.
AuthorsGreenberg S, el Khoury J, di Virgilio F, Kaplan EM, Silverstein SC
JournalJ Cell Biol
PubMed ID2026648
Phagocytosis of IgG-coated particles by macrophages is presumed to involve the actin-based cytoskeleton since F-actin accumulates beneath forming phagosomes, and particle engulfment is blocked by cytochalasins, drugs that inhibit actin filament assembly. However, it is unknown whether Fc receptor ligation affects the rate or extent of F-actin assembly during phagocytosis ... More
The role of presynaptic calcium in short-term enhancement at the hippocampal mossy fiber synapse.
AuthorsRegehr WG, Delaney KR, Tank DW
JournalJ Neurosci
PubMed ID8301352
The mossy fiber synapse between dentate granule cells and CA3 pyramidal cells in the guinea pig hippocampus shows a robust short-term synaptic enhancement. We have simultaneously measured presynaptic residual free calcium ([Ca2+]i) and postsynaptic field potentials at this synapse to examine the role of [Ca2+]i in this enhancement. Single action ... More
The role of Ca2+ in insulin-stimulated glucose transport in 3T3-L1 cells.
AuthorsWhitehead JP, Molero JC, Clark S, Martin S, Meneilly G, James DE
JournalJ Biol Chem
PubMed ID11375387
We have examined the requirement for Ca2+ in the signaling and trafficking pathways involved in insulin-stimulated glucose uptake in 3T3-L1 adipocytes. Chelation of intracellular Ca2+, using 1,2-bis (o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra (acetoxy- methyl) ester (BAPTA-AM), resulted in >95% inhibition of insulin-stimulated glucose uptake. The calmodulin antagonist, W13, inhibited insulin-stimulated glucose uptake ... More
Omnitemporal choreographies of all five STIM/Orai and IP3Rs underlie the complexity of mammalian Ca2+ signaling.
Authors
JournalCell Rep
PubMed ID33657364
Myosin V functions as a vesicle tether at the plasma membrane to control neurotransmitter release in central synapses.
Authors
JournalElife
PubMed ID30320552
The potassium channel subunit Kvβ1 serves as a major control point for synaptic facilitation.
Authors
JournalProc Natl Acad Sci U S A
PubMed ID33168717
Target-wide Induction and Synapse Type-Specific Robustness of Presynaptic Homeostasis.
Authors
JournalCurr Biol
PubMed ID31708391
Dysbindin links presynaptic proteasome function to homeostatic recruitment of low release probability vesicles.
Authors
JournalNat Commun
PubMed ID29348419
All three IP3 receptor isoforms generate Ca2+ puffs that display similar characteristics.
Authors
JournalSci Signal
PubMed ID30563861
Orai1 Channels Are Essential for Amplification of Glutamate-Evoked Ca2+ Signals in Dendritic Spines to Regulate Working and Associative Memory.
Authors
JournalCell Rep
PubMed ID33264616
IP3 mediated global Ca2+ signals arise through two temporally and spatially distinct modes of Ca2+ release.
Authors
JournalElife
PubMed ID32396066
TMBIM6/BI-1 contributes to cancer progression through assembly with mTORC2 and AKT activation.
Authors
JournalNat Commun
PubMed ID32782388
Chanzyme TRPM7 Mediates the Ca2+ Influx Essential for Lipopolysaccharide-Induced Toll-Like Receptor 4 Endocytosis and Macrophage Activation.