We have investigated the identity and intracellular cascade of responses resulting from activation of the endogenous 5-hydroxytryptamine receptor in the C6 rat glioma cell line. Sequence analysis of reverse transcription-polymerase chain reaction products derived from C6 glioma cell messenger RNA revealed complete homology with a portion of the rat 5-hydroxytryptamine2A ... More
Reversible inactivation of K+ channels of Vicia stomatal guard cells following the photolysis of caged inositol 1,4,5-trisphosphate.
AuthorsBlatt MR, Thiel G, Trentham DR
JournalNature
PubMed ID2388696
RECENT investigations suggest that cytoplasmic D-myo-inositol 1,4,5-trisphosphate (InsP3) functions as a second messenger in plants, as in animals, coupling environmental and other stimuli to intracellular Ca2+ release. Cytoplasmic levels of InsP3 and the turnover of several probable precursors in plants are affected by physiological stimuli--including light, osmotic stress and the ... More
Polarized Ca2+ release in saponin-permeabilized parotid acinar cells evoked by flash photolysis of 'caged' inositol 1,4,5-trisphosphate.
AuthorsTanimura A, Matsumoto Y, Tojyo Y
JournalBiochem J
PubMed ID9620881
'In exocrine acinar cells, agonist stimulation results in a polarized Ca2+ signal, termed the ''Ca2+ wave'', that propagates from the apical pole towards the basolateral region. We attempted to detect the inositol 1,4,5-trisphosphate (InsP3)-induced Ca2+ wave in saponin-permeabilized rat parotid acinar cells using a digital imaging system. The permeabilized acinar ... More
Intracellular astrocyte calcium waves in situ increase the frequency of spontaneous AMPA receptor currents in CA1 pyramidal neurons.
AuthorsFiacco TA, McCarthy KD
JournalJ Neurosci
PubMed ID14736858
'Spontaneous neurotransmitter release and activation of group I metabotropic glutamate receptors (mGluRs) each play a role in the plasticity of neuronal synapses. Astrocytes may contribute to short- and long-term synaptic changes by signaling to neurons via these processes. Spontaneous whole-cell AMPA receptor (AMPAR) currents were recorded in CA1 pyramidal cells ... More
Sustained Ca2+ signaling in mouse lacrimal acinar cells due to photolysis of "caged" glycerophosphoryl-myo-inositol 4,5-bisphosphate.
AuthorsBird GS, Obie JF, Putney JW
JournalJ Biol Chem
PubMed ID1325446
'In saponin-permeabilized mouse lacrimal acinar cells, glycerophosphoryl-myo-inositol 4,5-bisphosphate (GPIP2) activated the release of sequestered Ca2+ to the same extent as inositol 1,4,5-trisphosphate ((1,4,5)IP3) but with a potency about 1/10 that of (1,4,5)IP3. In lacrimal gland homogenates, [3H]GPIP2 was metabolized to two compounds which upon anion exchange high performance liquid chromatography ... More
Caffeine inhibits inositol trisphosphate-mediated liberation of intracellular calcium in Xenopus oocytes.
AuthorsParker I, Ivorra I
JournalJ Physiol
PubMed ID1844813
'1. Voltage-clamp recording of Ca(2+)-activated chloride currents in Xenopus oocytes was used to study the effects of caffeine on the liberation of intracellular Ca2+ induced by photo-release of inositol 1,4,5-trisphosphate (InsP3) from caged InsP3. Bath application of caffeine, at concentrations between 0.1 and 10 mM, reduced or abolished the current ... More
3':5'-cyclic guanosine monophosphate (cGMP) potentiates the inositol 1,4,5-trisphosphate-evoked Ca2+ release in guinea-pig hepatocytes.
AuthorsGuihard G, Combettes L, Capiod T
JournalBiochem J
PubMed ID8836128
'The effect of cGMP on noradrenaline-induced intracellular Ca2+ mobilization was investigated in whole-cell voltage-clamped guinea-pig hepatocytes. Treatment of the cells with 8-Br-cGMP (1-500 microM) resulted in an increase in the sensitivity of the cells to noradrenaline and to inositol 1,4,5-trisphosphate (InsP3) photo-released from caged InsP3. The positive effect of 8-Br-cGMP ... More
Nuclear and cytosolic calcium are regulated independently.
'Nuclear calcium (Ca(2+)) regulates a number of important cellular processes, including gene transcription, growth, and apoptosis. However, it is unclear whether Ca(2+) signaling is regulated differently in the nucleus and cytosol. To investigate this possibility, we examined subcellular mechanisms of Ca(2+) release in the HepG2 liver cell line. The type ... More
Developmental changes in the distribution of the endoplasmic reticulum and inositol 1,4,5-trisphosphate receptors and the spatial pattern of Ca2+ release during maturation of hamster oocytes.
AuthorsShiraishi K, Okada A, Shirakawa H, Nakanishi S, Mikoshiba K, Miyazaki S
JournalDev Biol
PubMed ID7649386
'During maturation of hamster oocytes, the distribution of the endoplasmic reticulum (ER) and inositol 1,4,5-trisphosphate receptors (InsP3Rs) was found to change dramatically, as observed using confocal microscopy with DiI and electron microscopy for the ER and immunohistochemistry for InsP3Rs. In immature oocytes at the germinal vesicle (GV) stage, ER and ... More
Calcium signalling during chemotaxis.
AuthorsFay FS, Gilbert SH, Brundage RA
JournalCiba Found Symp
PubMed ID7587614
'The role of Ca2+ in chemotaxis of eosinophils from the newt Taricha granulosa was investigated using fluorescent indicators and digital imaging microscopy. In response to serum chemoattractant, cytoplasmic Ca2+ concentration ([Ca2+]i) rises prior to polarization. In polarized locomoting cells [Ca2+]i gradients (tail-high-front-low) are always seen, and when cells turn [Ca2+]i ... More
Inhibitors of spasmogen-induced Ca2+ channel suppression in smooth muscle cells from small intestine.
AuthorsUnno T, Beech DJ, Komori S, Ohashi H
JournalBr J Pharmacol
PubMed ID9831900
'1. Whole-cell patch-clamp recordings were made from smooth muscle cells isolated from the longitudinal muscle layer of guinea-pig ileum. Carbachol (acting at muscarinic receptors) or histamine (acting at H1 histamine receptors) suppressed Ca2+ channel current. The effect of either agonist had an initial transient component followed by a sustained component. ... More
The M-phase-promoting factor modulates the sensitivity of the Ca2+ stores to inositol 1,4,5-trisphosphate via the actin cytoskeleton.
AuthorsLim D, Ercolano E, Kyozuka K, Nusco GA, Moccia F, Lange K, Santella L
JournalJ Biol Chem
PubMed ID12867432
'The resumption of the meiotic cycle (maturation) induced by 1-methyladenine in prophase-arrested starfish oocytes is indicated by the breakdown of the germinal vesicle and is characterized by the increased sensitivity of the Ca2+ stores to inositol 1,4,5-trisphosphate (InsP3) to InsP3 starting at the animal hemisphere (where the germinal vesicle was ... More
Local anesthetics inhibit receptors coupled to phosphoinositide signaling in Xenopus oocytes.
AuthorsTigyi J, Tigyi G, Liliom K, Miledi R
JournalPflugers Arch
PubMed ID9000427
'Effects and the mechanism of action of quaternary amine local anesthetics on ligand- and voltage-activated ion currents were studied using voltage-clamped ovarian follicles and oocytes from Xenopus laevis. The fast inward and slow outward currents in response to acetylcholine were unaltered by procaine, whereas the oscillatory and smooth inward chloride ... More
Receptor-mediated calcium signals in astroglia: multiple receptors, common stores and all-or-nothing responses.
AuthorsShao Y, McCarthy KD
JournalCell Calcium
PubMed ID7621532
'Calcium signals following activation of P2Y purinergic, alpha 1 adrenergic, and muscarinic cholinergic receptors were examined in individual astroglial cells. ATP, phenylephrine and carbachol, each increased intracellular calcium levels ([Ca2+]i) to similar amplitudes in the presence or absence of extracellular Ca2+. The dose-response relationship showed that less than an order ... More
Ca(2+) signals mediated by Ins(1,4,5)P(3)-gated channels in rat ureteric myocytes.
'Localized Ca(2+)-release signals (puffs) and propagated Ca(2+) waves were characterized in rat ureteric myocytes by confocal microscopy. Ca(2+) puffs were evoked by photorelease of low concentrations of Ins(1,4,5)P(3) from a caged precursor and by low concentrations of acetylcholine; they were also observed spontaneously in Ca(2+)-overloaded myocytes. Ca(2+) puffs showed some ... More
Elemental propagation of calcium signals in response-specific patterns determined by environmental stimulus strength.
AuthorsGoddard H, Manison NF, Tomos D, Brownlee C
JournalProc Natl Acad Sci U S A
PubMed ID10677557
'Plant cells can respond qualitatively and quantitatively to a wide range of environmental signals. Ca(2+) is used as an intracellular signal for volume regulation in response to external osmotic changes. We show here that the spatiotemporal patterns of hypo-osmotically induced Ca(2+) signals vary dramatically with stimulus strength in embryonic cells ... More
Buffer kinetics shape the spatiotemporal patterns of IP3-evoked Ca2+ signals.
AuthorsDargan SL, Parker I
JournalJ Physiol
PubMed ID14555715
'Ca2+ liberation through inositol 1,4,5-trisphosphate receptors (IP3Rs) plays a universal role in cell regulation, and specificity of cell signalling is achieved through the spatiotemporal patterning of Ca2+ signals. IP3Rs display Ca2+-induced Ca2+ release (CICR), but are grouped in clusters so that regenerative Ca2+ signals may remain localized to individual clusters, ... More
Spatiotemporal analysis of calcium dynamics in the nucleus of hamster oocytes.
AuthorsShirakawa H, Miyazaki S
JournalJ Physiol
PubMed ID8814604
'1. Subcellular Ca2+ dynamics inside and around the nucleus of immature hamster oocytes were analysed with confocal Ca2+ imaging. 2. The ratio value between emission intensity of two injected fluorescent Ca2+ indicators, Calcium Green and Fura Red, was almost uniform over the entire oocyte, suggesting that nucleoplasmic Ca2+ concentration ([Ca2+]n) ... More
Molecular and functional characterization of inositol trisphosphate receptors during early zebrafish development.
AuthorsAshworth R, Devogelaere B, Fabes J, Tunwell RE, Koh KR, De Smedt H, Patel S
JournalJ Biol Chem
PubMed ID17331947
'Fluctuations in cytosolic Ca(2+) are crucial for a variety of cellular processes including many aspects of development. Mobilization of intracellular Ca(2+) stores via the production of inositol trisphosphate (IP(3)) and the consequent activation of IP(3)-sensitive Ca(2+) channels is a ubiquitous means by which diverse stimuli mediate their cellular effects. Although ... More
Role of cytosolic Ca2+ in inhibition of InsP3-evoked Ca2+ release in Xenopus oocytes.
AuthorsIlyin V, Parker I
JournalJ Physiol
PubMed ID7932238
'1. Calcium liberation induced in Xenopus oocytes by flash photorelease of inositol 1,4,5-trisphosphate (InsP3) from a caged precursor was monitored by confocal microfluorimetry. The object was to determine whether inhibition of Ca2+ release seen with paired flashes arose as a direct consequence of elevated cytosolic free [Ca2+]. 2. Responses evoked ... More
Type III InsP3 receptor channel stays open in the presence of increased calcium.
AuthorsHagar RE, Burgstahler AD, Nathanson MH, Ehrlich BE
JournalNature
PubMed ID9817204
'The inositol 1,4,5-trisphosphate receptor (InsP3R) is the main calcium(Ca2+) release channel in most tissues. Three isoforms have been identified, but only types I and II InsP3R have been characterized. Here we examine the functional properties of the type III InsP3R because this receptor is restricted to the trigger zone from ... More
Inositol trisphosphate-mediated Ca2+ influx into Xenopus oocytes triggers Ca2+ liberation from intracellular stores.
AuthorsYao Y, Parker I
JournalJ Physiol
PubMed ID8254510
'1. Inositol 1,4,5-trisphosphate (InsP3) functions as a second messenger by liberating Ca2+ from intracellular stores and by promoting influx of extracellular Ca2+. We examined whether Ca2+ influx modulates intracellular Ca2+ liberation in Xenopus oocytes by fluorescence monitoring of cytosolic free Ca2+ together with voltage clamp recording of Ca(2+)-activated Cl- membrane ... More
[Calcium and liver]
AuthorsTran D, Noel J, Claret M
JournalArch Int Physiol Biochim Biophys
PubMed ID7691222
'Cells expand energy to lower the concentration of free calcium in the cytosol ([Ca2+]i) to a very low level. Extracellular Ca2+ entering via channels situated in the plasma membrane is expelled into the extracellular medium by a Ca(2+)-Mg(2+)-ATPase or by Na(+)-Ca2+ exchangers. The Ca2+ that enters the cell is sequestered, ... More
A role for second messengers in the control of activation-associated modification of the surface of Trichinella spiralis infective larvae.
AuthorsModha J, Kusel JR, Kennedy MW
JournalMol Biochem Parasitol
PubMed ID8538685
'The involvement of second messengers in the control of activation-induced changes to the surface of Trichinella spiralis infective larvae was investigated using membrane-permeant photo-activatable ''caged'' compounds to alter intracellular levels of inositol trisphosphate (IP3), calcium ions (Ca2+) and cyclic AMP (cAMP). Activation of larvae by incubation in culture medium containing ... More
Functional heterogeneity of calcium release by inositol trisphosphate in single Purkinje neurones, cultured cerebellar astrocytes, and peripheral tissues.
AuthorsKhodakhah K, Ogden D
JournalProc Natl Acad Sci U S A
PubMed ID8506344
'Purkinje neurones of the cerebellar cortex are rich in receptors for the Ca-mobilizing second messenger inositol trisphosphate (InsP3) in association with intracellular Ca stores. Cytosolic Ca ions are important in regulating neuronal excitability but it has proved difficult to demonstrate InsP3-evoked release of Ca in mammalian central neurones directly. Intracellular ... More
Novel paracrine signaling mechanism in the ocular ciliary epithelium.
AuthorsHirata K, Nathanson MH, Sears ML
JournalProc Natl Acad Sci U S A
PubMed ID9653195
'The ciliary body contains an epithelial bilayer consisting of an outer pigmented cell layer (PE) and an inner nonpigmented cell layer (NPE) responsible for aqueous humor secretion. Secretion may be mediated in part by cytosolic Ca2+ concentration ([Ca2+]i), but whether or how the two layers could coordinate their Ca2+ signals ... More
Mechanisms underlying InsP3-evoked global Ca2+ signals in mouse pancreatic acinar cells.
AuthorsFogarty KE, Kidd JF, Tuft DA, Thorn P
JournalJ Physiol
PubMed ID10922004
'In secretory epithelial cells, complex patterns of Ca2+ signals regulate physiological processes. How these patterns are generated is still not fully understood. In particular, the basis of global Ca2+ waves is not clear. We have studied regional differences in InsP3-evoked Ca2+ release in single mouse pancreatic acinar cells, using high-speed ... More
Agonist-specific behaviour of the intracellular Ca2+ response in rat hepatocytes.
AuthorsChatton JY, Cao Y, Stucki JW
JournalBiochem J
PubMed ID9371717
'A variety of agonists stimulate in hepatocytes a response that takes the shape of repetitive cytosolic free Ca2+ transients called Ca2+ oscillations. The shape of spikes and the pattern of oscillations in a given cell differ depending on the agonist of the phosphoinositide pathway that is applied. In this study, ... More
Voltage-gated Ca2+ channels and intracellular Ca2+ release regulate exocytosis in identified rat corticotrophs.
AuthorsTse A, Lee AK
JournalJ Physiol
PubMed ID11018107
'1. The patch clamp technique was used in conjunction with a fluorescent Ca2+ indicator (indo-1, or indo-1FF) to measure simultaneously cytosolic Ca2+ concentration ([Ca2+]i) and exocytosis (changes in membrane capacitance) in single, identified rat corticotrophs. 2. Exocytosis could be stimulated by extracellular Ca2+ entry (via voltage-gated Ca2+ channels). A train ... More
Impaired calcium release in cerebellar Purkinje neurons maintained in culture.
AuthorsWomack MD, Walker JW, Khodakhah K
JournalJ Gen Physiol
PubMed ID10694261
'Cerebellar Purkinje neurons demonstrate a form of synaptic plasticity that, in acutely prepared brain slices, has been shown to require calcium release from the intracellular calcium stores through inositol trisphosphate (InsP(3)) receptors. Similar studies performed in cultured Purkinje cells, however, find little evidence for the involvement of InsP(3) receptors. To ... More
2-Aminoethoxydiphenyl borate modulates kinetics of intracellular Ca(2+) signals mediated by inositol 1,4,5-trisphosphate-sensitive Ca(2+) stores in single pancreatic acinar cells of mouse.
AuthorsWu J, Kamimura N, Takeo T, Suga S, Wakui M, Maruyama T, Mikoshiba K
JournalMol Pharmacol
PubMed ID11093775
'Regulation of the kinetics of intracellular Ca(2+) signals with a novel, membrane-penetrable, inositol 1,4,5-trisphosphate (InsP(3)) receptor/Ca(2+) channel modulator, 2-amino-ethoxydiphenyl borate (2APB), has been investigated using patch-clamp, whole-cell recording to monitor Ca(2+)-activated Cl(-) currents in single isolated pancreatic acinar cells. 2APB itself fails to evoke a detectable current response but it ... More
Fast activation and inactivation of inositol trisphosphate-evoked Ca2+ release in rat cerebellar Purkinje neurones.
AuthorsKhodakhah K, Ogden D
JournalJ Physiol
PubMed ID8558468
'1. Calcium release from stores via inositol trisphosphate (InsP3) activation of intracellular Ca2+ receptor-channels is thought to have a role in regulating the excitability of cerebellar Purkinje neurones. The kinetic characteristics of InsP3 receptor activation in Purkinje neurones are reported here. 2. InsP3 was applied by flash photolysis of caged ... More
Delayed "all-or-none" activation of inositol 1,4,5-trisphosphate-dependent calcium signaling in single rat hepatocytes.
AuthorsChiavaroli C, Bird G, Putney JW
JournalJ Biol Chem
PubMed ID7523388
'When single rat hepatocytes were stimulated with the phospholipase C-activating hormone, vasopressin (from 300 pM to 1 microM), the [Ca2+]i signals were always "all-or-none" responses. At low concentrations of vasopressin, Ca2+ release was maximal because liberation of additional inositol 1,4,5-trisphosphate (IP3) by photolysis of its caged precursor at the top ... More
Repetitive calcium waves induced by fertilization in the nemertean worm Cerebratulus lacteus.
AuthorsStricker SA
JournalDev Biol
PubMed ID8660865
'To analyze fertilization-induced calcium dynamics in a protostome worm, unfertilized oocytes of the nemertean Cerebratulus lacteus were co-injected with calcium green (CG) and rhodamine (Rh) dextrans for dual-channel confocal imaging of early development. Based on CG/Rh ratioed images collected every 800 msec, fertilization elicits a "cortical flash" of elevated free ... More
Elementary events of InsP3-induced Ca2+ liberation in Xenopus oocytes: hot spots, puffs and blips.
AuthorsParker I, Choi J, Yao Y
JournalCell Calcium
PubMed ID8889202
'Liberation of sequestered Ca2+ ions in Xenopus oocytes by the second messenger inositol 1,4,5-trisphosphate (InP3) occurs from functionally discrete sites, which are spaced at intervals of several microns and probably represent clusterings of InsP3 receptor/channels (InsP3R) in the endoplasmic reticulum. As well as requiring InsP3, opening of release channels is ... More
Regulation of cell movement is mediated by stretch-activated calcium channels.
AuthorsLee J, Ishihara A, Oxford G, Johnson B, Jacobson K
JournalNature
PubMed ID10432119
'Intracellular calcium regulates many of the molecular processes that are essential for cell movement. It is required for the production of actomyosin-based contractile forces, the regulation of the structure and dynamics of the actin cytoskeletons, and the formation and disassembly of cell-substratum adhesions. Calcium also serves as a second messenger ... More
Two Ca2+ entry pathways mediate InsP3-sensitive store refilling in guinea-pig colonic smooth muscle.
AuthorsMcCarron JG, Flynn ER, Bradley KN, Muir TC
JournalJ Physiol
PubMed ID10811730
'Sarcolemma Ca2+ influx, necessary for store refilling, was well maintained, over a wide range (-70 to + 40 mV) of membrane voltages, in guinea-pig single circular colonic smooth muscle cells, as indicated by the magnitude of InsP3-evoked Ca2+ transients. This apparent voltage independence of store refilling was achieved by the ... More
Flash photolysis studies of excitation-contraction coupling, regulation, and contraction in smooth muscle.
AuthorsSomlyo AP, Somlyo AV
JournalAnnu Rev Physiol
PubMed ID2184779
'1. Flash photolysis of caged compounds of phenylephrine, inositol 1, 4, 5 trisphosphate (InsP3), GTP gamma S, ATP, and CTP has been successfully used to study excitation-contraction coupling, contractile regulation, and contraction in smooth muscle. Major processes explored with this method were (a) the delay between agonist-receptor interaction and contraction ... More
Cyclic ADP-ribose-gated Ca2+ release in sea urchin eggs requires an elevated.
AuthorsGuo X, Becker PL
JournalJ Biol Chem
PubMed ID9202011
'Cyclic ADP-ribose (cADPr) has been shown to release intracellular Ca2+ from sea urchin eggs and a variety of vertebrate cell types, although its mechanism of action remains elusive. We employed the caged version of cADPr to study the [Ca2+] transient kinetics in intact sea urchin eggs for insights into how ... More
Purinergic control of intercellular communication between Hensen's cells of the guinea-pig cochlea.
AuthorsLagostena L, Ashmore JF, Kachar B, Mammano F
JournalJ Physiol
PubMed ID11251051
'1. Hensen''s cells in the isolated cochlea were stimulated by extracellular adenosine 5''-triphosphate (ATP) applied to their endolymphatic surface while changes in membrane current and intracellular calcium concentration ([Ca2+]i) were measured simultaneously. The response consisted of (i) an initial rapid inward current accompanied by elevation of the [Ca2+]i, (ii) a ... More
Caged inositol 1,4,5-trisphosphate for studying release of Ca2+ from intracellular stores.
AuthorsCallamaras N, Parker I
JournalMethods Enzymol
PubMed ID9661160
Ca(2+)-dependent activation of Cl(-) currents in Xenopus oocytes is modulated by voltage.
AuthorsCallamaras N, Parker I
JournalAm J Physiol Cell Physiol
PubMed ID10751316
'Ca(2+)-activated Cl(-) currents (I(Cl,Ca)) were examined using fluorescence confocal microscopy to monitor intracellular Ca(2+) liberation evoked by flash photolysis of caged inositol 1,4, 5-trisphosphate (InsP(3)) in voltage-clamped Xenopus oocytes. Currents at +40 mV exhibited a steep dependence on InsP(3) concentration ([InsP(3)]), whereas currents at -140 mV exhibited a higher threshold ... 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
Membrane capacitance changes induced by thrombin and calcium in single endothelial cells cultured from human umbilical vein.
AuthorsCarter TD, Zupancic G, Smith SM, Wheeler-Jones C, Ogden D
JournalJ Physiol
PubMed ID9824722
'1. Vesicular secretion from single human umbilical vein endothelial cells (HUVECs) was monitored by changes in membrane capacitance (Cm). Secretion was evoked by dialysis with strongly buffered intracellular free Ca2+ concentrations ([Ca2+]i), flash photolysis of Ca2+-loaded DM-nitrophen or caged InsP3, or by thrombin. [Ca2+]i was monitored spectrofluorimetrically with furaptra. The ... More
Mechanisms of intracellular calcium release during hormone and neurotransmitter action investigated with flash photolysis.
AuthorsOgden DC, Khodakhah K, Carter TD, Gray PT, Capiod T
JournalJ Exp Biol
PubMed ID7903678
'To understand the complex time course of cytosolic Ca2+ signalling evoked by hormones and neurotransmitters, it is necessary to know the kinetics of steps in the second-messenger cascade, particularly cooperative and inhibitory interactions between components that might give rise to periodic fluctuations. In the case of inositol trisphosphate (InsP3)-evoked Ca2+ ... More
Feedback control of inositol trisphosphate signalling bycalcium.
AuthorsIino M, Tsukioka M
JournalMol Cell Endocrinol
PubMed ID8143923
'Inositol 1,4,5-trisphosphate (InsP3)-induced Ca2+ release depends on the cytoplasmic concentration of Ca2+ in a biphasic manner: activated with the increase in Ca2+ up to approximately 300 nM and inhibited by its further increase. Kinetic studies of the Ca2+ release with rapid increase in Ca2+ or InsP3 using respective caged compounds ... More
Ca2+ transients associated with openings of inositol trisphosphate-gated channels in Xenopus oocytes.
AuthorsParker I, Yao Y
JournalJ Physiol
PubMed ID8815201
'1. The mechanisms underlying inositol 1,4,5-trisphosphate (InsP3)-induced Ca2+ liberation were studied in Xenopus oocytes by using scanning and stationary-point confocal fluorescence microscopy to record Ca2+ signals evoked by photorelease of InsP3 from a caged precursor. 2. Fluorescence measurements from confocal images showed that increasing [InsP3] evoked three distinct modes of ... More
Determination of time-dependent inositol-1,4,5-trisphosphate concentrations during calcium release in a smooth muscle cell.
AuthorsFink CC, Slepchenko B, Loew LM
JournalBiophys J
PubMed ID10388786
'The level of [InsP3]cyt required for calcium release in A7r5 cells, a smooth muscle cell line, was determined by a new set of procedures using quantitative confocal microscopy to measure release of InsP3 from cells microinjected with caged InsP3. From these experiments, the [InsP3]cyt required to evoke a half-maximal calcium ... More
Inositol trisphosphate, calcium and muscle contraction.
AuthorsSomlyo AP, Walker JW, Goldman YE, Trentham DR, Kobayashi S, Kitazawa T, Somlyo AV
JournalPhilos Trans R Soc Lond B Biol Sci
PubMed ID2906146
'The identity of organelles storing intracellular calcium and the role of Ins(1,4,5)P3 in muscle have been explored with, respectively, electron probe X-ray microanalysis (EPMA) and laser photolysis of 'caged' compounds. The participation of G-protein(s) in the release of intracellular Ca2+ was determined in saponin-permeabilized smooth muscle. The sarcoplasmic reticulum (SR) ... More
Capacitative Ca2+ entry into Xenopus oocytes is sensitive to omega-conotoxins GVIA, MVIIA and MVIIC.
AuthorsLomax RB, Herrero CJ, García-Palomero E, García AG, Montiel C
JournalCell Calcium
PubMed ID9681186
'We have studied capacitative Ca2+ entry into Xenopus oocytes by depleting intracellular Ca2+ stores with inositol 1,4,5-trisphosphate or thapsigargin. Capacitative Ca2+ entry was evoked by hyperpolarisation and monitored via the Ca(2+)-activated Cl- current. Hyperpolarisation-evoked currents increased with extracellular [Ca2+] in the range 0.9-5 mM, and were reversibly inhibited by extracellular ... More
Radial localization of inositol 1,4,5-trisphosphate-sensitive Ca2+ release sites in Xenopus oocytes resolved by axial confocal linescan imaging.
AuthorsCallamaras N, Parker I
JournalJ Gen Physiol
PubMed ID9925819
'The radial localization and properties of elementary calcium release events ("puffs") were studied in Xenopus oocytes using a confocal microscope equipped with a piezoelectric focussing unit to allow rapid (>100 Hz) imaging of calcium signals along a radial line into the cell with a spatial resolution of <0.7 micrometer. Weak ... More
Expression and function of the gonadotropin-releasing hormone receptor are dependent on a conserved apolar amino acid in the third intracellular loop.
AuthorsChung HO, Yang Q, Catt KJ, Arora KK
JournalJ Biol Chem
PubMed ID10585457
'The coupling of agonist-activated heptahelical receptors to their cognate G proteins is often dependent on the amino-terminal region of the third intracellular loop. Like many G protein-coupled receptors, the gonadotropin-releasing hormone (GnRH) receptor contains an apolar amino acid in this region at a constant distance from conserved Pro and Tyr/Asn ... More
PI-3 kinase and IP3 are both necessary and sufficient to mediate NT3-induced synaptic potentiation.
AuthorsYang F, He X, Feng L, Mizuno K, Liu XW, Russell J, Xiong WC, Lu B
JournalNat Neurosci
PubMed ID11135641
'Signaling mechanisms underlying neurotrophic regulation of synaptic transmission are not fully understood. Here we show that neurotrophin-3 (NT3)-induced potentiation of synaptic transmission at the neuromuscular synapses is blocked by inhibition of phosphoinositide-3 kinase, phospholipase C-gamma or the downstream IP3 receptors of phospholipase C-gamma, but not by inhibition of MAP kinase. ... More
Cell-permeant caged InsP3 ester shows that Ca2+ spike frequency can optimize gene expression.
AuthorsLi W, Llopis J, Whitney M, Zlokarnik G, Tsien RY
JournalNature
PubMed ID9582076
'Inositol 1,4,5-trisphosphate (InsP3) releases calcium from intracellular stores and triggers complex waves and oscillations in levels of cytosolic free calcium. To determine which longer-term responses are controlled by oscillations in InsP3 and cytosolic free calcium, it would be useful to deliver exogenous InsP3, under spatial and temporal control, into populations ... More
Prolonged inactivation of nicotinic acid adenine dinucleotide phosphate-induced Ca2+ release mediates a spatiotemporal Ca2+ memory.
AuthorsChurchill GC, Galione A
JournalJ Biol Chem
PubMed ID11139579
'Although numerous extracellular stimuli are coupled to increases in intracellular Ca(2+), different stimuli are thought to achieve specificity by eliciting different spatiotemporal Ca(2+) increases. We investigated the effect of nicotinic acid adenine dinucleotide phosphate (NAADP) inactivation on spatiotemporal Ca(2+) signals in intact sea urchin eggs. The photorelease of NAADP but ... More
Local calcium release in dendritic spines required for long-term synaptic depression.
AuthorsMiyata M, Finch EA, Khiroug L, Hashimoto K, Hayasaka S, Oda SI, Inouye M, Takagishi Y, Augustine GJ, Kano M
JournalNeuron
PubMed ID11086997
'We have used rats and mice with mutations in myosin-Va to evaluate the range and function of IP3-mediated Ca2+ signaling in dendritic spines. In these mutants, the endoplasmic reticulum and its attendant IP3 receptors do not enter the postsynaptic spines of parallel fiber synapses on cerebellar Purkinje cells. Long-term synaptic ... More
5-HT2A receptor-mediated outward current in C6 glioma cells is mimicked by intracellular IP3 release.
AuthorsBartrup JT, Newberry NR
JournalNeuroreport
PubMed ID7522611
'The C6 glioma cell line possesses 5-HT2A receptors that have been shown to increase intracellular calcium levels. We have studied the electrophysiological response of these cells to 5-HT using the whole-cell recording method. Under voltage-clamp, 5-hydroxytryptamine (5-HT) produced an outward current in these cells which was inhibited by extracellularly applied ... More
Flash photolysis of caged inositol 1,4,5-trisphosphate activates plasma membrane calcium current in human T cells.
AuthorsMcDonald TV, Premack BA, Gardner P
JournalJ Biol Chem
PubMed ID8382682
'Sustained elevation of intracellular Ca2+ by cell surface receptors is often dependent on influx of Ca2+ across the plasma membrane through routes not involving voltage-gated Ca2+ channels. We demonstrate that intracellular release of inositol 1,4,5-trisphosphate (InsP3), either from stimulation of transfected human muscarinic receptors or from photolytic release of caged ... More
A role for phosphorylation of inositol 1,4,5-trisphosphate receptors in defining calcium signals induced by Peptide agonists in pancreatic acinar cells.
AuthorsStraub SV, Giovannucci DR, Bruce JI, Yule DI
JournalJ Biol Chem
PubMed ID12065595
'Stimulation of pancreatic acinar cells with acetylcholine (ACh) and cholecystokinin (CCK) results in an elevation of cytosolic calcium ([Ca(2+)](c)) through activation of inositol 1,4,5-trisphosphate receptors (InsP(3)R). The global temporal pattern of the [Ca(2+)](c) changes produced by ACh or CCK stimulation differs significantly. The hypothesis was tested that CCK stimulation results ... More
Seeing the machinery of live cells.
AuthorsTsien RY, Miyawaki A
JournalScience
PubMed ID9669950
Elevation of cytoplasmic calcium by caged calcium or caged inositol triphosphate initiates stomatal closure.
AuthorsGilroy S, Read ND, Trewavas AJ
JournalNature
PubMed ID2388697
Intercellular calcium signaling and flash photolysis of caged compounds. A sensitive method to evaluate gap junctional coupling.
AuthorsLeybaert L, Sanderson MJ
JournalMethods Mol Biol
PubMed ID11218662
Intracellular calcium releases facilitate induction of long-term depression.
AuthorsKato N, Isomura Y, Tanaka T
JournalNeuropharmacology
PubMed ID10727721
In visual cortex layer II/III pyramidal neurons, long-term depression (LTD) of synaptic currents was induced by a combination of the intracellular increase of inositol-1,4,5-trisphosphate (IP(3)), achieved by photolyzing caged-IP(3), and the tetanization to nearby cortex, but not by either of these two procedures alone. A facilitatory role of an IP(3)-induced ... More
Diversity and dynamics of dendritic signaling.
AuthorsHäusser M, Spruston N, Stuart GJ
JournalScience
PubMed ID11052929
Communication between neurons in the brain occurs primarily through synapses made onto elaborate treelike structures called dendrites. New electrical and optical recording techniques have led to tremendous advances in our understanding of how dendrites contribute to neuronal computation in the mammalian brain. The varied morphology and electrical and chemical properties ... More
Caged compounds: photorelease technology for control of cellular chemistry and physiology.
AuthorsEllis-Davies GC
JournalNat Methods
PubMed ID17664946
Caged compounds are light-sensitive probes that functionally encapsulate biomolecules in an inactive form. Irradiation liberates the trapped molecule, permitting targeted perturbation of a biological process. Uncaging technology and fluorescence microscopy are 'optically orthogonal': the former allows control, and the latter, observation of cellular function. Used in conjunction with other technologies ... More
Calcium buffering capacity of neuronal cell cytosol measured by flash photolysis of calcium buffer NP-EGTA.
AuthorsFleet A, Ellis-Davies G, Bolsover S
JournalBiochem Biophys Res Commun
PubMed ID9784424
N1E-115 mouse neuroblastoma cells were injected with a calcium buffer/indicator solution to allow both ratiometric measurement of free calcium concentration and the release of calcium ions upon UV flash. The solution contained sulforhodamine, a marker dye used to estimate the volume injected; fluo-3, a calcium indicator, and NP-EGTA, a high ... More
NAADP mobilizes Ca(2+) from reserve granules, lysosome-related organelles, in sea urchin eggs.
AuthorsChurchill GC, Okada Y, Thomas JM, Genazzani AA, Patel S, Galione A
JournalCell
PubMed ID12464181
Nicotinic acid adenine dinucleotide phosphate (NAADP) mobilizes Ca(2+) in many cells and species. Unlike other Ca(2+)-mobilizing messengers, NAADP mobilizes Ca(2+) from an unknown store that is not the endoplasmic reticulum, the store traditionally associated with messenger-mediated Ca(2+) signaling. Here, we demonstrate the presence of a Ca(2+) store in sea urchin ... More
Involvement of inositol trisphosphate in cerebellar long-term depression.
AuthorsKasono K, Hirano T
JournalNeuroreport
PubMed ID7539306
We examined the role of increases in Ca2+ from different sources in the induction of long-term depression (LTD) of glutamate or AMPA responsiveness in cultured Purkinje neurones. Photolysis of caged Ca2+ or caged inositol 1,4,5-trisphosphate (InsP3) as well as depolarization was used to increase Ca2+ concentration. Heparin, contained in a ... More
Inositol trisphosphate releases stored calcium to block voltage-dependent calcium channels in single smooth muscle cells.
AuthorsKomori S, Bolton TB
JournalPflugers Arch
PubMed ID1653941
In single cells obtained by enzymic treatment of rabbit small-intestinal smooth muscle, and held under voltage clamp by patch pipette in the whole-cell recording mode, release of inositol trisphosphate (InsP3) from its caged precursor by flash photolysis caused complete inhibition of the voltage-dependent calcium current. No inhibition was seen in ... More
Elementary calcium-release units induced by inositol trisphosphate.
AuthorsHorne JH, Meyer T
JournalScience
PubMed ID9180077
The extent to which inositol 1,4,5-trisphosphate (InsP3)-induced calcium signals are localized is a critical parameter for understanding the mechanism of effector activation. The spatial characteristics of InsP3-mediated calcium signals were determined by targeting a dextran-based calcium indicator to intracellular membranes through the in situ addition of a geranylgeranyl lipid group. ... More
Photoactivation of caged compounds in single living cells: an application to the study of cell locomotion.
AuthorsIshihara A, Gee K, Schwartz S, Jacobson K, Lee J
JournalBiotechniques
PubMed ID9266081
Caged compounds are molecules whose biological function is masked until UV light induces a photo-chemical reaction that converts the molecules into a biologically active state. These probes provide very powerful tools in cell biology research, since the activation can be precisely controlled temporally and spatially by limiting their exposure to ... More
Calcium dependence of exocytosis and endocytosis at the cochlear inner hair cell afferent synapse.
AuthorsBeutner D, Voets T, Neher E, Moser T
JournalNeuron
PubMed ID11301027
Release of neurotransmitter at the inner hair cell (IHC) afferent synapse is a fundamental step in translating sound into auditory nerve excitation. To study the Ca2+ dependence of the underlying vesicle fusion and subsequent endocytosis, we combined Ca2+ uncaging with membrane capacitance measurements in mouse IHCs. Rapid elevations in [Ca2+]i ... More
Inhibition by Ca2+ of inositol trisphosphate-mediated Ca2+ liberation: a possible mechanism for oscillatory release of Ca2+.
AuthorsParker I, Ivorra I
JournalProc Natl Acad Sci U S A
PubMed ID2296584
Light-flash photolysis of caged inositol 1,4,5-trisphosphate (InsP3) was used to generate reproducible transients of free InsP3 in Xenopus oocytes, and the resulting liberation of Ca2+ from intracellular stores was monitored by recording Ca2+-activated membrane currents and by use of the fluorescent Ca2+ indicator fluo-3. InsP3-mediated Ca2+ release was inhibited by ... More
Photochemically generated cytosolic calcium pulses and their detection by fluo-3.
AuthorsKao JP, Harootunian AT, Tsien RY
JournalJ Biol Chem
PubMed ID2498309
Fluo-3, one member of a family of new fluorescent Ca2+ indicators excitable at wavelengths in the visible (Minta, A., Kao, J. P. Y., and Tsien, R. Y. (1989) J. Biol. Chem. 264, 8171-8178), has been tested in living cells. We demonstrate that fluo-3 can be loaded into fibroblasts and lymphocytes ... More
Rhythmic exocytosis stimulated by GnRH-induced calcium oscillations in rat gonadotropes.
AuthorsTse A, Tse FW, Almers W, Hille B
JournalScience
PubMed ID8385366
In pituitary gonadotropes, gonadotropin-releasing hormone (GnRH) induces the rhythmic release of Ca2+ from an inositol 1,4,5-trisphosphate (IP3)-sensitive store. Simultaneous measurement of the concentration of cytosolic free Ca2+ ([Ca2+]i) and exocytosis in single identified gonadotropes showed that each elevation of [Ca2+]i induced a burst of exocytosis. These phenomena were largely suppressed ... More
Effects of 1-methyladenine on nuclear Ca2+ transients and meiosis resumption in starfish oocytes are mimicked by the nuclear injection of inositol 1,4,5-trisphosphate and cADP-ribose.
AuthorsSantella L, Kyozuka K
JournalCell Calcium
PubMed ID9232348
The treatment of prophase-arrested starfish oocytes with the hormone 1-methyladenine (1-MA) induces the elevation of Ca2+ in both the cytoplasm and the germinal vesicle (nucleus), and is followed by the resumption of meiosis. The injection of the modulators of the intracellular Ca2+ channels inositol 1,4,5-trisphosphate (InsP3) or cyclic adenosine diphosphate ... More
Organelle selection determines agonist-specific Ca2+ signals in pancreatic acinar and beta cells.
AuthorsYamasaki M, Masgrau R, Morgan AJ, Churchill GC, Patel S, Ashcroft SJ, Galione A
JournalJ Biol Chem
PubMed ID14660554
How different extracellular stimuli can evoke different spatiotemporal Ca2+ signals is uncertain. We have elucidated a novel paradigm whereby different agonists use different Ca2+-storing organelles ("organelle selection") to evoke unique responses. Some agonists select the endoplasmic reticulum (ER), and others select lysosome-related (acidic) organelles, evoking spatial Ca2+ responses that mirror ... More
Restricted photorelease of biologically active molecules near the plasma membrane.
AuthorsSuga T, Hirano M, Takayanagi M, Koshimoto H, Watanabe A
JournalBiochem Biophys Res Commun
PubMed ID9878552
An evanescent wave of ultraviolet light was successfully used to release biologically active molecules from caged compounds in living cells. The evanescent wave was generated by the total internal reflection in a limited region near the plasma membrane attached to the illuminated interface. At first, the photolysis efficiency of the ... More
Flash photolysis studies of the localization of calcium release sites in rat parotid isolated acinar cells.
AuthorsHassoni AA, Gray PT
JournalJ Physiol
PubMed ID7525949
1. The temporal relationship between cytosolic free Ca2+ concentration ([Ca2+]i) and activation of membrane current responses in single rat parotid acinar cells has been examined. Activation of muscarinic receptors by carbachol (CCh) at -40 mV (midway between EK and ECl under our experimental conditions) frequently evoked biphasic current responses, application ... More
Localization of phospholipase Cbeta isozymes in the mouse cerebellum.
AuthorsSugiyama T, Hirono M, Suzuki K, Nakamura Y, Aiba A, Nakamura K, Nakao K, Katsuki M, Yoshioka T
JournalBiochem Biophys Res Commun
PubMed ID10558892
To elucidate the role of phospholipase Cbeta (PLCbeta) isozymes in the cerebellum, the distributions of PLCbeta3 and PLCbeta4 were examined in wild-type and PLCbeta4-deficient mutant mice using immunohistochemistry, and the functions were evaluated by measurement of type 1 metabotropic glutamate receptor (mGluR1)-mediated inward current and Ca(2+) mobilization. In wild-type mice, ... More
Control of local actin assembly by membrane fusion-dependent compartment mixing.
AuthorsYu HY, Bement WM
JournalNat Cell Biol
PubMed ID17237773
Local actin assembly is associated with sites of exocytosis in processes ranging from phagocytosis to compensatory endocytosis. Here, we examine whether the trigger for actin-coat assembly around exocytosing Xenopus egg cortical granules is 'compartment mixing'--the union of the contents of the plasma membrane with that of the secretory granule membrane. ... More
Ca2+ depletion and inositol 1,4,5-trisphosphate-evoked activation of Ca2+ entry in single guinea pig hepatocytes.
AuthorsGuihard G, Noel J, Capiod T
JournalJ Biol Chem
PubMed ID10788451
Store-operated Ca(2+) entry was investigated by monitoring the Ca(2+)-dependent K(+) permeability in voltage-clamped guinea pig hepatocytes. In physiological conditions, intracellular Ca(2+) stores are discharged following agonist stimulation, but depletion of this stores can be achieved using Ca(2+)-Mg(2+)-ATPase inhibitors such as 2,5-di(tert-butyl)-1,4-benzohydroquinone and thapsigargin. The effect of internal Ca(2+) store depletion ... More
Calcium release from cardiac sarcoplasmic reticulum induced by photorelease of calcium or Ins(1,4,5)P3.
The ability of Ca2+ or inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] to release Ca2+ from cardiac sarcoplasmic reticulum (SR) was investigated using saponin-skinned ventricular trabeculae from rats. To overcome diffusion delays, rapid increases in the concentrations of Ca2+ and Ins(1,4,5)P3 were produced by laser photolysis of "caged Ca2+" (Nitr-5) and "caged Ins(1,4,5)P3". Photolysis ... More
Kinetics of smooth and skeletal muscle activation by laser pulse photolysis of caged inositol 1,4,5-trisphosphate.
AuthorsWalker JW, Somlyo AV, Goldman YE, Somlyo AP, Trentham DR
JournalNature
PubMed ID3494954
Inositol 1,4,5-trisphosphate (InsP3) can stimulate skinned smooth and skeletal muscle to contract by initiating Ca2+ release from the sarcoplasmic reticulum. Whether this process is an integral component of the in vivo muscle activation mechanism was tested by releasing InsP3 rapidly within skinned muscle fibers of rabbit main pulmonary artery and ... More
Selective stimulation of astrocyte calcium in situ does not affect neuronal excitatory synaptic activity.
Astrocytes are considered the third component of the synapse, responding to neurotransmitter release from synaptic terminals and releasing gliotransmitters--including glutamate--in a Ca(2+)-dependent manner to affect neuronal synaptic activity. Many studies reporting astrocyte-driven neuronal activity have evoked astrocyte Ca(2+) increases by application of endogenous ligands that directly activate neuronal receptors, making ... More
Regulation of calcium signals in the nucleus by a nucleoplasmic reticulum.
AuthorsEchevarría W, Leite MF, Guerra MT, Zipfel WR, Nathanson MH
JournalNat Cell Biol
PubMed ID12717445
Calcium is a second messenger in virtually all cells and tissues. Calcium signals in the nucleus have effects on gene transcription and cell growth that are distinct from those of cytosolic calcium signals; however, it is unknown how nuclear calcium signals are regulated. Here we identify a reticular network of ... More
IP3 receptor blockade fails to prevent intracellular Ca2+ release by ET-1 and alpha-thrombin.
AuthorsMathias RS, Mikoshiba K, Michikawa T, Miyawaki A, Ives HE
JournalAm J Physiol
PubMed ID9696687
The effect of inositol 1,4,5-trisphosphate (IP3) receptor blockade on platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), endothelin-1 (ET-1), or alpha-thrombin receptor-mediated intracellular Ca2+ (Ca2+i) release was examined using fura 2 microspectrofluorometry in single Chinese hamster ovary cells and myoblasts. Blockade of the IP3 receptor was achieved by microinjection of ... More
Phasic characteristic of elementary Ca(2+) release sites underlies quantal responses to IP(3).
AuthorsCallamaras N, Parker I
JournalEMBO J
PubMed ID10899115
Ca(2+) liberation by inositol 1,4,5-trisphosphate (IP(3)) is 'quantal', in that low [IP(3)] causes only partial Ca(2+) release, but further increasing [IP(3)] evokes more release. This characteristic allows cells to generate graded Ca(2+) signals, but is unexpected, given the regenerative nature of Ca(2+)-induced Ca(2+) release through IP(3) receptors. Two models have ... More
Lithium blocks cell cycle transitions in the first cell cycles of sea urchin embryos, an effect rescued by myo-inositol.
AuthorsBecchetti A, Whitaker M
JournalDevelopment
PubMed ID9102297
Lithium is a classical inhibitor of the phosphoinositide pathway and is teratogenic. We report the effects of lithium on the first cell cycles of sea urchin (Lytechinus pictus) embryos. Embryos cultured in 400 mM lithium chloride sea water showed marked delay to the cell cycle and a tendency to arrest ... More
A high-resolution, confocal laser-scanning microscope and flash photolysis system for physiological studies.
AuthorsParker I, Callamaras N, Wier WG
JournalCell Calcium
PubMed ID9223680
We describe the construction of a high-resolution confocal laser-scanning microscope, and illustrate its use for studying elementary Ca2+ signalling events in cells. An avalanche photodiode module and simple optical path provide a high efficiency system for detection of fluorescence signals, allowing use of a small confocal aperture giving near diffraction-limited ... More
Electroporation loading and photoactivation of caged InsP3: tools to investigate the relation between cellular ATP release in response to intracellular InsP3 elevation.
AuthorsBraet K, Mabilde C, Cabooter L, Rapp G, Leybaert L
JournalJ Neurosci Methods
PubMed ID14687677
Photolytic liberation of InsP(3) in single cells triggers cell-to-cell propagating calcium changes that are communicated by a gap junctional and a paracrine purinergic pathway involving InsP(3)-triggered ATP release. We investigated the relation between the InsP(3) stimulus and the resulting ATP release in ECV304 cells using UV photolysis of caged compounds ... More
Inositol 1,4,5-trisphosphate-induced Ca(2+)-transient and outward K+ current in single smooth muscle cells of guinea pig small intestine.
AuthorsIto S, Bolton TB
JournalJpn J Pharmacol
PubMed ID8791166
The effects of inositol 1,4,5-trisphosphate (InsP3) released from caged InsP3 by flash photolysis on free intracellular Ca2+ concentration, [Ca2+]i, and outward K+ current were simultaneously examined in a single smooth muscle cell of guinea pig small intestine using a patch pipette solution containing Indo-1 (0.1 mM), caged InsP3 (50 microM) ... More
Inhibition of inositol 1,4,5-trisphosphate-induced Ca2+ release by cAMP-dependent protein kinase in a living cell.
AuthorsTertyshnikova S, Fein A
JournalProc Natl Acad Sci U S A
PubMed ID9465064
Interaction of intracellular free calcium ([Ca2+]i) and cAMP signaling mechanisms was examined in intact single megakaryocytes by using a combination of single-cell fluorescence microscopy to measure [Ca2+]i and flash photolysis of caged Ca2+, inositol 1,4, 5-trisphosphate (IP3), or cAMP to elevate rapidly the concentration of these compounds inside the cell. ... More
Inositol 1,4,5-trisphosphate- and ryanodine-sensitive Ca2+ release channel-dependent Ca2+ signalling in rat portal vein myocytes.
AuthorsBoittin FX, Coussin F, Macrez N, Mironneau C, Mironneau J
JournalCell Calcium
PubMed ID9681193
Ca2+ signalling events were analyzed in single myocytes from rat portal vein by using a laser confocal microscope combined with the patch-clamp technique. Increase in inositol 1,4,5-trisphosphate (InsP3) concentration was obtained by photorelease from a caged precursor or intracellular dialysis of 3F-InsP3. Low InsP3 concentrations activated either small elevations of ... More
Local calcium signalling by inositol-1,4,5-trisphosphate in Purkinje cell dendrites.
AuthorsFinch EA, Augustine GJ
JournalNature
PubMed ID9874372
The second messenger inositol-1,4,5-trisphosphate (InsP3) releases Ca2+ from intracellular Ca2+ stores by activating specific receptors on the membranes of these stores. In many cells, InsP3 is a global signalling molecule that liberates Ca2+ throughout the cytoplasm. However, in neurons the situation might be different, because synaptic activity may produce InsP3 ... More
Inositol 1,4,5-trisphosphate directs Ca(2+) flow between mitochondria and the Endoplasmic/Sarcoplasmic reticulum: a role in regulating cardiac autonomic Ca(2+) spiking.
AuthorsJaconi M, Bony C, Richards SM, Terzic A, Arnaudeau S, Vassort G, Pucéat M
JournalMol Biol Cell
PubMed ID10793156
The signaling role of the Ca(2+) releaser inositol 1,4, 5-trisphosphate (IP(3)) has been associated with diverse cell functions. Yet, the physiological significance of IP(3) in tissues that feature a ryanodine-sensitive sarcoplasmic reticulum has remained elusive. IP(3) generated by photolysis of caged IP(3) or by purinergic activation of phospholipase Cgamma slowed ... More
Calsenilin reverses presenilin-mediated enhancement of calcium signaling.
AuthorsLeissring MA, Yamasaki TR, Wasco W, Buxbaum JD, Parker I, LaFerla FM
JournalProc Natl Acad Sci U S A
PubMed ID10900016
Most cases of autosomal-dominant familial Alzheimer's disease are linked to mutations in the presenilin genes (PS1 and PS2). In addition to modulating beta-amyloid production, presenilin mutations also produce highly specific and selective alterations in intracellular calcium signaling. Although the molecular mechanisms underlying these changes are not known, one candidate molecular ... More
AuthorsLeissring MA, Paul BA, Parker I, Cotman CW, LaFerla FM
JournalJ Neurochem
PubMed ID10037477
Perturbations in intracellular Ca2+ signaling may represent one mechanism underlying Alzheimer's disease (AD). The presenilin-1 gene (PS1), associated with the majority of early onset familial AD cases, has been implicated in this signaling pathway. Here we used the Xenopus oocyte expression system to investigate in greater detail the role of ... More
Morphological control of inositol-1,4,5-trisphosphate-dependent signals.
Inositol-1,4,5-trisphosphate (InsP(3))-mediated calcium signals represent an important mechanism for transmitting external stimuli to the cell. However, information about intracellular spatial patterns of InsP(3) itself is not generally available. In particular, it has not been determined how the interplay of InsP(3) generation, diffusion, and degradation within complex cellular geometries can control ... More