Mechanisms of photoswitch conjugation and light activation of an ionotropic glutamate receptor.
AuthorsGorostiza P,Volgraf M,Numano R,Szobota S,Trauner D,Isacoff EY
JournalProceedings of the National Academy of Sciences of the United States of America
PubMed ID17578923
The analysis of cell signaling requires the rapid and selective manipulation of protein function. We have synthesized photoswitches that covalently modify target proteins and reversibly present and withdraw a ligand from its binding site due to photoisomerization of an azobenzene linker. We describe here the properties of a glutamate photoswitch ... More
Simultaneous measurement of intracellular pH and Ca2+ in insulin-secreting cells by spectral imaging microscopy.
AuthorsMartínez-Zaguilán R,Gurulé MW,Lynch RM
JournalThe American journal of physiology
PubMed ID8967445
Functional implications of calcium permeability of the channel formed by pannexin 1.
Although human pannexins (PanX) are homologous to gap junction molecules, their physiological function in vertebrates remains poorly understood. Our results demonstrate that overexpression of PanX1 results in the formation of Ca(2+)-permeable gap junction channels between adjacent cells, thus, allowing direct intercellular Ca(2+) diffusion and facilitating intercellular Ca(2+) wave propagation. More ... More
Rescue of vasopressin V2 receptor mutants by chemical chaperones: specificity and mechanism.
AuthorsRobben JH,Sze M,Knoers NV,Deen PM
JournalMolecular biology of the cell
PubMed ID16267275
Because missense mutations in genetic diseases of membrane proteins often result in endoplasmic reticulum (ER) retention of functional proteins, drug-induced rescue of their cell surface expression and understanding the underlying mechanism are of clinical value. To study this, we tested chemical chaperones and sarco(endo)plasmic reticulum Ca(2+) ATPase pump inhibitors on ... More
Disruption of a single copy of the SERCA2 gene results in altered Ca2+ homeostasis and cardiomyocyte function.
Nicotinic acid adenine dinucleotide phosphate (NAADP(+)) is an essential regulator of T-lymphocyte Ca(2+)-signaling.
AuthorsBerg I,Potter BV,Mayr GW,Guse AH
JournalThe Journal of cell biology
PubMed ID10931869
Microinjection of human Jurkat T-lymphocytes with nicotinic acid adenine dinucleotide phosphate (NAADP(+)) dose-dependently stimulated intracellular Ca(2+)-signaling. At a concentration of 10 nM NAADP(+) evoked repetitive and long-lasting Ca(2+)-oscillations of low amplitude, whereas at 50 and 100 nM, a rapid and high initial Ca(2+)-peak followed by trains of smaller Ca(2+)-oscillations was ... More
Sequential SNARE assembly underlies priming and triggering of exocytosis.
AuthorsChen YA,Scales SJ,Scheller RH
JournalNeuron
PubMed ID11343652
Identification of residues of CXCR4 critical for human immunodeficiency virus coreceptor and chemokine receptor activities.
AuthorsBrelot A,Heveker N,Montes M,Alizon M
JournalThe Journal of biological chemistry
PubMed ID10825158
Testosterone signaling through internalizable surface receptors in androgen receptor-free macrophages.
AuthorsBenten WP,Lieberherr M,Stamm O,Wrehlke C,Guo Z,Wunderlich F
JournalMolecular biology of the cell
PubMed ID10512854
Testosterone acts on cells through intracellular transcription-regulating androgen receptors (ARs). Here, we show that mouse IC-21 macrophages lack the classical AR yet exhibit specific nongenomic responses to testosterone. These manifest themselves as testosterone-induced rapid increase in intracellular free [Ca(2+)], which is due to release of Ca(2+) from intracellular Ca(2+) stores. ... More
A Glu-496 to Ala polymorphism leads to loss of function of the human P2X7 receptor.
The multifunctional ADP-ribosyl cyclase, CD38, catalyzes the cyclization of NAD(+) to cyclic ADP-ribose (cADPr). The latter gates Ca(2+) release through microsomal membrane-resident ryanodine receptors (RyRs). We first cloned and sequenced full-length CD38 cDNA from a rabbit osteoclast cDNA library. The predicted amino acid sequence displayed 59, 59, and 50% similarity, ... More
Multiple functional P2X and P2Y receptors in the luminal and basolateral membranes of pancreatic duct cells.
AuthorsLuo X,Zheng W,Yan M,Lee MG,Muallem S
JournalThe American journal of physiology
PubMed ID10444396
Examination of the function of RANTES, MIP-1alpha, and MIP-1beta following interaction with heparin-like glycosaminoglycans.
AuthorsAli S,Palmer AC,Banerjee B,Fritchley SJ,Kirby JA
JournalThe Journal of biological chemistry
PubMed ID10766793
Molecular cloning of a novel variant of the pituitary adenylate cyclase-activating polypeptide (PACAP) receptor that stimulates calcium influx by activation of L-type calcium channels.
AuthorsChatterjee TK,Sharma RV,Fisher RA
JournalThe Journal of biological chemistry
PubMed ID8943280
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a novel neuropeptide that produces its biological effects by interacting with G protein-coupled receptors. Molecular cloning of the PACAP receptor revealed the existence of five splice variant receptor forms differing in the third intracellular loop region, with four variants activating both adenylyl cyclase and ... More
Switch to anaerobic glucose metabolism with NADH accumulation in the beta-cell model of mitochondrial diabetes. Characteristics of betaHC9 cells deficient in mitochondrial DNA transcription.
To elucidate the mechanism underlying diabetes caused by mitochondrial gene mutations, we created a model by applying 0.4 microg/ml ethidium bromide (EtBr) to the murine pancreatic beta cell line betaHC9; in this model, transcription of mitochondrial DNA, but not that of nuclear DNA, was suppressed in association with impairment of ... More
Extracellular ATP and UTP control the generation of reactive oxygen intermediates in human macrophages through the opening of a charybdotoxin-sensitive Ca2+-dependent K+ channel.
AuthorsSchmid-Antomarchi H, Schmid-Alliana A, Romey G, Ventura MA, Breittmayer V, Millet MA, Husson H, Moghrabi B, Lazdunski M, Rossi B
JournalJ Immunol
PubMed ID9550424
Human monocyte-derived macrophages possess a NADPH oxidase that catalyzes superoxide formation upon phagocytosis. Extracellular ATP per se does not activate NADPH oxidase but potentiates superoxide generation triggered by opsonized zymosan. UTP can substitute for ATP with the same efficiency, suggesting that ATP mediates its effects specifically through P2U receptors. Extracellular ... More
Reactive oxygen species and calcium homeostasis in cultured human intestinal smooth muscle cells.
AuthorsBielefeldt K, Whiteis CA, Sharma RV, Abboud FM, Conklin JL
JournalAm J Physiol
PubMed ID9227480
Reactive oxygen species (ROS) significantly alter cell function. We examined the effects of hydrogen peroxide (H2O2) and xanthine/xanthine oxidase (X/XO) on isolated intestinal muscle cells. We assessed cell viability with the exclusion dye trypan blue and assayed the effects of H2O2 and X/XO on the intracellular redox state with the ... More
Extracellular activities of human granzyme A. Monocyte activation by granzyme A versus alpha-thrombin.
AuthorsSower LE, Froelich CJ, Allegretto N, Rose PM, Hanna WD, Klimpel GR
JournalJ Immunol
PubMed ID8786323
Granzymes, serine proteases located in the granules of cytotoxic T cel ls and NK cells, are essential for induction of target cell apoptosis. However, since cytotoxic cells constitutively secrete a portion of their synthesized granzymes, these proteases could mediate extracellular functions independent of their role in the lytic event. Thrombin, ... More
Sr2+ can become incorporated into an agonist-sensitive, cytoplasmic Ca2+ store in a cell line derived from the equine sweat gland epithelium.
AuthorsKo WH, Pediani JD, Bovell DL, Wilson SM
JournalExperientia
PubMed ID7649240
We have explored the properties of a Ca(2+)-dependent cell-signalling pathway that becomes active when cultured equine sweat gland cells are stimulated with ATP. The ATP-regulated, Ca(2+)-influx pathway allowed Sr2+ to enter the cytoplasm but permitted only a minimal influx of Ba2+. Experiments in which cells were repeatedly stimulated with ATP ... More
Creation of an inositol 1,4,5-trisphosphate-sensitive Ca2+ store in secretory granules of insulin-producing cells.
AuthorsBlondel O, Bell GI, Moody M, Miller RJ, Gibbons SJ
JournalJ Biol Chem
PubMed ID7961623
A rapid rise in the cytosolic free Ca2+ concentration due to influx of extracellular Ca2+ or mobilization from intracellular stores is the primary trigger for exocytosis from secretory cells. Our understanding as to the precise role of Ca2+ mobilization has been complicated by the presence of several types of Ca2+ ... More
Human olfactory neurons respond to odor stimuli with an increase in cytoplasmic Ca2+.
The sense of smell allows terrestrial animals to collect information about the chemical nature of their environment through the detection of airborne molecules. In humans smell is believed to play an important role in protecting the organism from environmental hazards such as fire, gas leaks and spoiled food, in determining ... More
Spontaneous cytosolic calcium pulsing detected in Xenopus melanotrophs: modulation by secreto-inhibitory and stimulant ligands.
AuthorsShibuya I, Douglas WW
JournalEndocrinology
PubMed ID8386613
The purpose of the experiments was to examine the behavior of cytosolic Ca2+ ([Ca2+]i) in individual pituitary melanotrophs and how that is affected by physiological ligands that inhibit or stimulate melanotroph secretion. Melanotrophs were dispersed from neurointermediate lobes of Xenopus laevis adapted to a black background, and [Ca2+]i was measured ... More
Characterization of cardiotin, a structural component in the myocard.
AuthorsSchaart G, van der Ven PF, Ramaekers FC
JournalEur J Cell Biol
PubMed ID8269977
The characterization and subcellular distribution of cardiotin, a structural component of striated muscle, is described using a monoclonal antibody. This high molecular mass component (> 300 kDa) is expressed in the myocard of several species and to a lesser extent also in skeletal muscle. Cardiotin is not found in smooth ... More
Evidence for agonist-induced export of intracellular Ca2+ in epithelial cells.
There is increasing evidence that some agonists not only induce intracellular Ca2+ increases, due to store release and transmembranous influx, but also that they stimulate Ca2+ efflux. We have investigated the agonist-stimulated response on the intracellular Ca2+ activity ([Ca2+]i) in the presence of thapsigargin (10(-8) mol/l, TG) in HT29 and ... More
Fluorescence digital image analysis of glucose-induced [Ca2+]i oscillations in mouse pancreatic islets of Langerhans.
AuthorsValdeolmillos M, Nadal A, Soria B, GarcÃa-Sancho J
JournalDiabetes
PubMed ID8325454
At intermediate glucose concentrations, [Ca2+]i (intracellular calcium) measured in single islets of Langerhans undergo oscillations that are caused by glucose-induced bursting of electrical activity. Using digital video imaging of fura-2--loaded islets, we have analyzed the spatial distribution of [Ca2+]i in response to the natural secretagogue glucose and the KATP channel ... More
Possible role of surface potential in the gating mechanism of Ca2+ channels in cat adrenal chromaffin cells: studies with fura-2 microfluorometry.
AuthorsSorimachi M, Nishimura S, Yamagami K
JournalBrain Res
PubMed ID1322223
The cytosolic free Ca2+ concentration ([Ca]in) in isolated cat chromaffin cells was measured by fura-2 microfluorometry. During 30 mM KCl depolarization or sucrose substitution for NaCl, a reduction in external Ca2+ concentration under optimal conditions paradoxically caused a rise in [Ca]in and, in separate experiments, in catecholamine secretion. The results ... More
Effect of low extracellular Ca2+ on growth, spreading area, cytoplasmic Ca2+ concentration, and intracellular pH in normal and transformed human fibroblasts.
AuthorsYoshida T, Takahashi Y, Takashima S
JournalJ Cell Physiol
PubMed ID8425911
The transformation of certain cells reduces the requirement of extracellular Ca2+ for growth. The SV-40 transformed human lung fibroblasts, WI-38 VA13, require less Ca2+ than normal WI-38 cells. Spreading area of the normal cells decreases when cultured in 10 microM Ca2+ medium. Intracellular calcium concentration ([Ca2+]i) of the normal and ... More
Gap junction-mediated intercellular diffusion of Ca2+ in cultured human corporal smooth muscle cells.
AuthorsChrist GJ, Moreno AP, Melman A, Spray DC
JournalAm J Physiol
PubMed ID1325115
Ratio imaging using the calcium-sensitive probe fura-2 was employed to study intracellular calcium concentrations and intercellular calcium flux through gap junctions in homogeneous vascular smooth muscle cell cultures derived from the human corpora cavernosa. Microinjection techniques demonstrated that fura-2 free acid was freely diffusible through gap junctions between cultured cells. ... More
Time course of changes in concentration of intracellular free calcium in cultured cerebrovascular smooth muscle cells exposed to oxyhemoglobin.
AuthorsTakanashi Y, Weir BK, Vollrath B, Kasuya H, Macdonald RL, Cook D
JournalNeurosurgery
PubMed ID1620296
A culture of smooth muscle cells obtained from monkey middle cerebral arteries was developed to allow quantitative assessment of intracellular calcium and immunofluorescence analysis after various periods of exposure to oxyhemoglobin. Intracellular calcium concentration was examined for up to 7 days after a single exposure to oxyhemoglobin. Intracellular calcium concentrations ... More
Intracellular calcium in NCB-20 cells: elevation by depolarization and ethanol but not by glutamate.
AuthorsChan J, Greenberg DA
JournalBrain Res
PubMed ID1675910
Intracellular Ca2+, measured in NCB-20 cells with the fluorescent indicator fura-2, was elevated by K(+)-depolarization and by ethanol, but not by the excitatory amino acids L-glutamate and N-methyl-D-aspartate. These amino acids failed to raise intracellular Ca2+ levels even in the presence of elevated extracellular Ca2+, in the absence of extracellular ... More
Intracellular vascular muscle Ca2+ modulation in genetic hypertension.
AuthorsErne P, Hermsmeyer K
JournalHypertension
PubMed ID2759676
Distribution of intracellular free calcium concentration (Ca2+) was compared in spontaneously hypertensive rat (SHR) and Wistar-Kyoto (WKY) rat isolated vascular muscle cells at rest and during stimulation by K+ with Ca2+ agonist or antagonist. Ca2+ activity was quantitated at each point within vascular muscle cells loaded with fura-2 at fluorescence ... More
Muscarinic agonists cause calcium influx and calcium mobilization in forebrain neurons in vitro.
AuthorsReynolds IJ, Miller RJ
JournalJ Neurochem
PubMed ID2723657
We have examined the effects of the muscarinic agonist carbachol on the intracellular free Ca2+ concentration ([Ca2+]i) in primary cultures of neurons from rat forebrain using the Ca2+-sensitive fluorescent dye fura-2. Addition of carbachol increased the [Ca2+]i in approximately 60% of cells studied. Oxotremorine-M, but not pilocarpine, mimicked the effects ... More
Release of intracellular calcium by two different second messengers in airway epithelium.
AuthorsMcCann JD, Bhalla RC, Welsh MJ
JournalAm J Physiol
PubMed ID2475035
To better understand regulation of Cl- secretion by airway epithelia, we measured the intracellular Ca2+ concentration ([Ca2+]c) using the Ca2+ indicator fura-2 and a fluorescent microscope imaging system. We examined receptor-mediated changes in [Ca2+]c in response to two Cl- secretagogues: the beta-adrenergic agonist isoproterenol and the peptide hormone bradykinin. Isoproterenol ... More
Polyamines are intracellular messengers in the beta-adrenergic regulation of Ca2+ fluxes, [Ca2+]i and membrane transport in rat heart myocytes.
AuthorsKoenig H, Goldstone AD, Lu CY
JournalBiochem Biophys Res Commun
PubMed ID2839169
The beta-adrenergic agonist 1-isoproterenol (0.1 microM) evokes an acute (less than 5-10 sec) transient increase in the activity of ornithine decarboxylase (ODC), and the levels of polyamines (putrescine, spermidine, spermine) in acutely isolated rat ventricular myocytes. Isoproterenol rapidly (less than 15 sec) increases 45Ca influx and efflux, decreases [Ca2+]i, and ... More
Use of manganese to discriminate between calcium influx and mobilization from internal stores in stimulated human neutrophils.
AuthorsMerritt JE, Jacob R, Hallam TJ
JournalJ Biol Chem
PubMed ID2536366
Stimulation of human neutrophils with f-met-leu-phe, platelet-activating factor, or leukotriene B4 resulted in an increase in [Ca2+]i. The [Ca2+]i rise was greater in the presence than absence of external Ca2+; the component that was dependent on external Ca2+ was blocked by Ni2+, or could be reconstituted by addition of external ... More
Effects of the peptide toxin from Microcystis aeruginosa on intracellular calcium, pH and membrane integrity in mammalian cells.
AuthorsFalconer IR, Runnegar MT
JournalChem Biol Interact
PubMed ID3119237
Extracts of water blooms of the toxic cyanobacterium Microcystis aeruginosa showed a range of toxicities not related to their ability to lyse mammalian red cells. The HPLC-purified heptapeptide toxin (mol. wt. 1035) from Microcystis did not lyse red cells at up to 500-fold higher concentrations than that required to kill ... More
Inhibitory effect of ginsenosides on NMDA receptor-mediated signals in rat hippocampal neurons.
AuthorsKim S, Ahn K, Oh TH, Nah SY, Rhim H
JournalBiochem Biophys Res Commun
PubMed ID12163009
Alternative medicines such as herbal products are increasingly being used for preventive and therapeutic purposes. Ginseng is the best known and most popular herbal medicine used worldwide. In spite of some beneficial effects of ginseng on the CNS, little scientific evidence shows at the cellular level. In the present study, ... More
Dominant regulation of interendothelial cell gap formation by calcium-inhibited type 6 adenylyl cyclase.
AuthorsCioffi DL, Moore TM, Schaack J, Creighton JR, Cooper DM, Stevens T
JournalJ Cell Biol
PubMed ID12082084
Acute transitions in cytosolic calcium ([Ca2+]i) through store-operated calcium entry channels catalyze interendothelial cell gap formation that increases permeability. However, the rise in [Ca2+]i only disrupts barrier function in the absence of a rise in cAMP. Discovery that type 6 adenylyl cyclase (AC6; EC 4.6.6.1) is inhibited by calcium entry ... More
Muscarinic receptors modulate intracellular Ca(2+) concentration in hyaline cells of the chicken basilar papilla.
AuthorsLippe WR, Zirpel L, Stone JS
JournalJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
PubMed ID12073083
Nonsensory hyaline cells border the sensory epithelium of the auditory end-organ (basilar papilla) in birds and reptiles. Their innervation by cochlear cholinergic efferent fibers and the presence of contractile proteins suggest that hyaline cells may actively regulate basilar membrane mechanics. The cholinergic pharmacology of hyaline cells was studied by measuring ... More
Sevoflurane depolarizes pre-synaptic mitochondria in the central nervous system.
BACKGROUND: Volatile anaesthetics protect the heart from ischaemic injury by activating mitochondrial signalling pathways. The aim of this study was to test whether sevoflurane, which is increasingly used in neuroanaesthesia, affects mitochondrial function in the central nervous system by altering the mitochondrial membrane potential (DeltaPsi(m)). METHODS: In order to correlate ... More
A single class II myosin modulates T cell motility and stopping, but not synapse formation.
AuthorsJacobelli J, Chmura SA, Buxton DB, Davis MM, Krummel MF
JournalNat Immunol
PubMed ID15064761
'Upon encountering an antigen, motile T cells stop crawling, change morphology and ultimately form an ''immunological synapse''. Although myosin motors are thought to mediate various aspects of this process, the molecules involved and their exact roles are not defined. Here we show that nonmuscle myosin heavy chain IIA, or MyH9, ... More
Phospholipase D1 production of phosphatidic acid at the plasma membrane promotes exocytosis of large dense-core granules at a late stage.
AuthorsZeniou-Meyer M, Zabari N, Ashery U, Chasserot-Golaz S, Haeberlé AM, Demais V, Bailly Y, Gottfried I, Nakanishi H, Neiman AM, Du G, Frohman MA, Bader MF, Vitale N
JournalJ Biol Chem
PubMed ID17540765
'Substantial efforts have recently been made to demonstrate the importance of lipids and lipid-modifying enzymes in various membrane trafficking processes, including calcium-regulated exocytosis of hormones and neurotransmitters. Among bioactive lipids, phosphatidic acid (PA) is an attractive candidate to promote membrane fusion through its ability to change membrane topology. To date, ... More
Drosophila Hsc70-4 is critical for neurotransmitter exocytosis in vivo.
AuthorsBronk P, Wenniger JJ, Dawson-Scully K, Guo X, Hong S, Atwood HL, Zinsmaier KE
JournalNeuron
PubMed ID11395008
'Previous in vitro studies of cysteine-string protein (CSP) imply a potential role for the clathrin-uncoating ATPase Hsc70 in exocytosis. We show that hypomorphic mutations in Drosophila Hsc70-4 (Hsc4) impair nerve-evoked neurotransmitter release, but not synaptic vesicle recycling in vivo. The loss of release can be restored by increasing external or ... More
AuthorsChiang AS, Lin WY, Liu HP, Pszczolkowski MA, Fu TF, Chiu SL, Holbrook GL
JournalProc Natl Acad Sci U S A
PubMed ID11773617
'In vertebrates, the N-methyl-D-aspartate subtype of glutamate receptors (NMDAR) appears to play a role in neuronal development, synaptic plasticity, memory formation, and pituitary activity. However, functional NMDAR have not yet been characterized in insects. We have now demonstrated immunohistochemically glutamatergic nerve terminals in the corpora allata of an adult female ... More
Measurement of glucose uptake and intracellular calcium concentration in single, living pancreatic beta-cells.
AuthorsYamada K, Nakata M, Horimoto N, Saito M, Matsuoka H, Inagaki N
JournalJ Biol Chem
PubMed ID10748091
'There has been no method previously to measure both glucose transport and its effect on the various intracellular functions in single, living mammalian cells. A fluorescent derivative of d-glucose, 2-[N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG), that we have developed has made such measurements possible. COS-1 cells that overexpress the human glucose transporter GLUT2 ... More
Regulation of a calcium-dependent tyrosine kinase in vascular smooth muscle cells by angiotensin II and platelet-derived growth factor. Dependence on calcium and the actin cytoskeleton.
AuthorsBrinson AE, Harding T, Diliberto PA, He Y, Li X, Hunter D, Herman B, Earp HS, Graves LM
JournalJ Biol Chem
PubMed ID9430717
'A novel, p125FAK homologue, CADTK, has been detected in neural, epithelial, or hematopoietic cells but not in fibroblasts. We now demonstrate CADTK expression in a mesenchymal cell, rat aortic smooth muscle cells (RSMC). Angiotensin II (Ang II) or platelet-derived growth factor (PDGF-BB and PDGF-AA) markedly stimulated CADTK tyrosine phosphorylation in ... More
Antiangiogenesis signals by endostatin.
AuthorsShichiri M, Hirata Y
JournalFASEB J
PubMed ID11292666
'Endostatin is a potent endogenous angiogenesis inhibitor that induces regression of tumors in mice. Neither an extracellular receptor for endostatin nor intracellular signals that result in the regression of tumor vascular beds have been identified. We demonstrate that endostatin, but not angiostatin, at comparable concentrations to those used in in ... More
Modulation of the in situ activity of tissue transglutaminase by calcium and GTP.
AuthorsZhang J, Lesort M, Guttmann RP, Johnson GV
JournalJ Biol Chem
PubMed ID9442073
'Tissue transglutaminase (tTG) is a calcium-dependent enzyme that catalyzes the posttranslational modification of proteins by transamidation of specific polypeptide-bound glutamine residues. Previous in vitro studies have demonstrated that the transamidating activity of tTG requires calcium and is inhibited by GTP. To investigate the endogenous regulation of tTG, a quantitative in ... More
Diversity in the neural circuitry of cold sensing revealed by genetic axonal labeling of transient receptor potential melastatin 8 neurons.
AuthorsTakashima Y, Daniels RL, Knowlton W, Teng J, Liman ER, McKemy DD,
JournalJ Neurosci
PubMed ID18094254
'Sensory nerves detect an extensive array of somatosensory stimuli, including environmental temperatures. Despite activating only a small cohort of sensory neurons, cold temperatures generate a variety of distinct sensations that range from pleasantly cool to painfully aching, prickling, and burning. Psychophysical and functional data show that cold responses are mediated ... More
Protein kinase A-mediated phosphorylation of serine 357 of the mouse prostacyclin receptor regulates its coupling to G(s)-, to G(i)-, and to G(q)-coupled effector signaling.
AuthorsLawler OA, Miggin SM, Kinsella BT
JournalJ Biol Chem
PubMed ID11443126
'The prostacyclin receptor (IP) is primarily coupled to G alpha(s)-dependent activation of adenylyl cyclase; however, a number of studies indicate that the IP may couple to other secondary effector systems perhaps in a species-specific manner. In the current study, we investigated the specificity of G protein:effector coupling by the mouse ... More
G(i)-mediated Cas tyrosine phosphorylation in vascular endothelial cells stimulated with sphingosine 1-phosphate: possible involvement in cell motility enhancement in cooperation with Rho-mediated pathways.
AuthorsOhmori T, Yatomi Y, Okamoto H, Miura Y, Rile G, Satoh K, Ozaki Y
JournalJ Biol Chem
PubMed ID11056155
'Since blood platelets release sphingosine 1-phosphate (Sph-1-P) upon activation, it is important to examine the effects of this bioactive lipid on vascular endothelial cell functions from the viewpoint of platelet-endothelial cell interactions. In the present study, we examined Sph-1-P-stimulated signaling pathways related to human umbilical vein endothelial cell (HUVEC) motility, ... More
Evidence that Ca(2+) cycling by the plasma membrane Ca(2+)-ATPase increases the 'excitability' of the extracellular Ca(2+)-sensing receptor.
AuthorsDe Luisi A, Hofer AM
JournalJ Cell Sci
PubMed ID12640037
'The extracellular Ca(2+)-sensing receptor (CaR) is a widely expressed G-protein-coupled receptor that translates information about [Ca(2+)] in the extracellular milieu to the interior of the cell, usually via intracellular Ca(2+) signaling pathways. Using fura-2 imaging of cytoplasmic [Ca(2+)], we observed that HEK293 cells expressing CaR oscillated readily under conditions permissive ... More
Determination of the relationship between T cell responsiveness and the number of MHC-peptide complexes using specific monoclonal antibodies.
AuthorsReay PA, Matsui K, Haase K, Wulfing C, Chien YH, Davis MM
JournalJ Immunol
PubMed ID10820237
'We describe the generation of three mAbs that recognize the complex of the class II MHC molecule IEk bound to a peptide derived from the carboxyl terminus of moth cytochrome c (residues 95-103). Reactivities of these mAbs are sensitive to single alterations in the sequence of both helices of the ... More
Distinct functions of Gq and G11 proteins in coupling alpha1-adrenoreceptors to Ca2+ release and Ca2+ entry in rat portal vein myocytes.
AuthorsMacrez-Leprêtre N, Kalkbrenner F, Schultz G, Mironneau J
JournalJ Biol Chem
PubMed ID9030598
'In this study, we identified the subunit composition of Gq and G11 proteins coupling alpha1-adrenoreceptors to increase in cytoplasmic Ca2+ concentration ([Ca2+]i) in rat portal vein myocytes maintained in short-term primary culture. We used intranuclear antisense oligonucleotide injection to inhibit selectively the expression of subunits of G protein. Increases in ... More
Extrasynaptic release of dopamine in a retinal neuron: activity dependence and transmitter modulation.
AuthorsPuopolo M, Hochstetler SE, Gustincich S, Wightman RM, Raviola E
JournalNeuron
PubMed ID11343656
'Extrasynaptic release of dopamine is well documented, but its relation to the physiological activity of the neuron is unclear. Here we show that in absence of presynaptic active zones, solitary cell bodies of retinal dopaminergic neurons release by exocytosis packets of approximately 40,000 molecules of dopamine at irregular intervals and ... More
Selective regulation of endogenous G protein-coupled receptors by arrestins in HEK293 cells.
AuthorsMundell SJ, Benovic JL
JournalJ Biol Chem
PubMed ID10777589
'Arrestins play an important role in regulating desensitization and trafficking of G protein-coupled receptors (GPCRs). However, limited insight into the specificity of arrestin-mediated regulation of GPCRs is currently available. Recently, we used an antisense strategy to reduce arrestin levels in HEK293 cells and characterize the role of arrestins on endogenous ... More
Functional specialization of calreticulin domains.
AuthorsNakamura K, Zuppini A, Arnaudeau S, Lynch J, Ahsan I, Krause R, Papp S, De Smedt H, Parys JB, Muller-Esterl W, Lew DP, Krause KH, Demaurex N, Opas M, Michalak M
JournalJ Cell Biol
PubMed ID11524434
'Calreticulin is a Ca2+-binding chaperone in the endoplasmic reticulum (ER), and calreticulin gene knockout is embryonic lethal. Here, we used calreticulin-deficient mouse embryonic fibroblasts to examine the function of calreticulin as a regulator of Ca2+ homeostasis. In cells without calreticulin, the ER has a lower capacity for Ca2+ storage, although ... More
The B cell-specific major raft protein, Raftlin, is necessary for the integrity of lipid raft and BCR signal transduction.
AuthorsSaeki K, Miura Y, Aki D, Kurosaki T, Yoshimura A
JournalEMBO J
PubMed ID12805216
'Recent evidence indicates that membrane microdomains, termed lipid rafts, have a role in B-cell activation as platforms for B-cell antigen receptor (BCR) signal initiation. To gain an insight into the possible functioning of lipid rafts in B cells, we applied liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methodologies to ... More
Regulation of Drosophila TRPL channels by immunophilin FKBP59.
AuthorsGoel M, Garcia R, Estacion M, Schilling WP
JournalJ Biol Chem
PubMed ID11514552
'Transient receptor potential and transient receptor potential-like (TRPL) are Ca(2+)-permeable cation channels found in Drosophila photoreceptor cells associated with large multimeric signaling complexes held together by the scaffolding protein, INAD. To identify novel proteins involved in channel regulation, Drosophila INAD was used as bait in a yeast two-hybrid screen of ... More
Inhibition of Kv2.1 voltage-dependent K+ channels in pancreatic beta-cells enhances glucose-dependent insulin secretion.
AuthorsMacDonald PE, Sewing S, Wang J, Joseph JW, Smukler SR, Sakellaropoulos G, Wang J, Saleh MC, Chan CB, Tsushima RG, Salapatek AM, Wheeler MB
JournalJ Biol Chem
PubMed ID12270920
'Voltage-dependent (Kv) outward K(+) currents repolarize beta-cell action potentials during a glucose stimulus to limit Ca(2+) entry and insulin secretion. Dominant-negative "knockout" of Kv2 family channels enhances glucose-stimulated insulin secretion. Here we show that a putative Kv2.1 antagonist (C-1) stimulates insulin secretion from MIN6 insulinoma cells in a glucose- and ... More
Recombinant expression of the plasma membrane Na(+)/Ca(2+) exchanger affects local and global Ca(2+) homeostasis in Chinese hamster ovary cells.
AuthorsBrini M, Manni S, Carafoli E
JournalJ Biol Chem
PubMed ID12145298
'The cardiac type Na(+)/Ca(2+) exchanger (NCX1) has been transiently expressed in Chinese hamster ovary cells, which do not contain an endogenous exchanger, together with aequorin chimeras that are targeted to different intracellular compartments to investigate intracellular Ca(2+) homeostasis. The expression of NCX decreased the endoplasmic reticulum Ca(2+) concentration, [Ca(2+)](er), in ... More
Trp1, a candidate protein for the store-operated Ca(2+) influx mechanism in salivary gland cells.
AuthorsLiu X, Wang W, Singh BB, Lockwich T, Jadlowiec J, O'Connell B, Wellner R, Zhu MX, Ambudkar IS
JournalJ Biol Chem
PubMed ID10652333
'The trp gene family has been proposed to encode the store-operated Ca(2+) influx (SOC) channel(s). This study examines the role of Trp1 in the SOC mechanism of salivary gland cells. htrp1, htrp3, and Trp1 were detected in the human submandibular gland cell line (HSG). HSG cells stably transfected with htrp1alpha ... More
Contributions of glycoprotein Ib and the seven transmembrane domain receptor to increases in platelet cytoplasmic [Ca2+] induced by alpha-thrombin.
AuthorsGreco NJ, Tandon NN, Jones GD, Kornhauser R, Jackson B, Yamamoto N, Tanoue K, Jamieson GA
JournalBiochemistry
PubMed ID8547272
'The individual contributions of glycoprotein Ib (GPIb) and the seven transmembrane domain receptor (STDR) to increases in platelet [Ca2+]i induced by alpha-thrombin or the tethered ligand peptide (TLP; SFLLRNPNDKYEPF) have been determined in control platelets, in platelets where the thrombin binding site on GPIb was blocked with the monoclonal antibodies ... More
Cadherins mediate intercellular mechanical signaling in fibroblasts by activation of stretch-sensitive calcium-permeable channels.
AuthorsKo KS, Arora PD, McCulloch CA
JournalJ Biol Chem
PubMed ID11466312
'Cells in mechanically active environments form extensive, cadherin-mediated intercellular junctions that are important in tissue remodeling and differentiation. Currently, it is unknown whether adherens junctions in connective tissue fibroblasts transmit mechanical signals and coordinate multicellular adaptations to physical forces. We hypothesized that cadherins mediate intercellular mechanotransduction by activating calcium-permeable, stretch-sensitive ... More
Localization and regulation by vitamin D of calcium transport proteins in rabbit cortical collecting system.
AuthorsVan Baal J, Yu A, Hartog A, Fransen JA, Willems PH, Lytton J, Bindels RJ
JournalAm J Physiol
PubMed ID8945992
'The 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3]-induced expression of Na+/Ca2+ exchanger, Ca(2+)-adenosinetriphosphatase (Ca(2+)-ATPase), and calbindin-D28k was investigated in the rabbit distal nephron. Immunocytochemical studies in rabbit kidney sections revealed colocalization of the three Ca2+ transport proteins in the majority of cells in the distal nephron, including connecting tubules and cortical collecting ducts. ... More
Monitoring dynamic changes in free Ca2+ concentration in the endoplasmic reticulum of intact cells.
AuthorsMontero M, Brini M, Marsault R, Alvarez J, Sitia R, Pozzan T, Rizzuto R
JournalEMBO J
PubMed ID8521803
'Direct monitoring of the free Ca2+ concentration in the lumen of the endoplasmic reticulum (ER) is an important but still unsolved experimental problem. We have shown that a Ca(2+)-sensitive photoprotein, aequorin, can be addressed to defined subcellular compartments by adding the appropriate targeting sequences. By engineering a new aequorin chimera ... More
Alteration of macrophage function by a Trypanosoma cruzi membrane mucin.
Authorsde Diego J, Punzón C, Duarte M, Fresno M
JournalJ Immunol
PubMed ID9366425
'Cytokines secreted by macrophages play important roles in the immune response to Trypanosoma cruzi. Here, we report that a purified glycosylphosphatidylinositol (GPI)-anchored mucin from the T. cruzi membrane, Ag C10, is able to bind to the macrophage cell surface and blocks the subsequent binding of mAb against CD62L/L-selectin, whereas binding ... More
A self-restricted CD38-connexin 43 cross-talk affects NAD+ and cyclic ADP-ribose metabolism and regulates intracellular calcium in 3T3 fibroblasts.
AuthorsBruzzone S, Franco L, Guida L, Zocchi E, Contini P, Bisso A, Usai C, De Flora A
JournalJ Biol Chem
PubMed ID11602597
'Connexin 43 (Cx43) hexameric hemichannels, recently demonstrated to mediate NAD(+) transport, functionally interact in the plasma membrane of several cells with the ectoenzyme CD38 that converts NAD(+) to the universal calcium mobilizer cyclic ADP-ribose (cADPR). Here we demonstrate that functional uncoupling between CD38 and Cx43 in CD38-transfected 3T3 murine fibroblasts ... More
Stabilization of cortical actin induces internalization of transient receptor potential 3 (Trp3)-associated caveolar Ca2+ signaling complex and loss of Ca2+ influx without disruption of Trp3-inositol trisphosphate receptor association.
AuthorsLockwich T, Singh BB, Liu X, Ambudkar IS
JournalJ Biol Chem
PubMed ID11524429
'Ca(2+) influx via plasma membrane Trp3 channels is proposed to be regulated by a reversible interaction with inositol trisphosphate receptor (IP(3)R) in the endoplasmic reticulum. Condensation of the cortical actin layer has been suggested to physically disrupt this interaction and inhibit Trp3-mediated Ca(2+) influx. This study examines the effect of ... More
IL-3 induces down-regulation of CCR3 protein and mRNA in human eosinophils.
AuthorsDulkys Y, Kluthe C, Buschermöhle T, Barg I, Knöss S, Kapp A, Proudfoot AE, Elsner J
JournalJ Immunol
PubMed ID11544337
'Cytokines and chemokines are responsible for the attraction and activation of eosinophils in allergic and inflammatory diseases. Whereas cytokines such as IL-3, IL-5, and GM-CSF activate eosinophils via heterodimeric receptors containing a distinct alpha-chain (binding domain) and a common beta-chain (signaling domain), chemokines such as eotaxin activate eosinophils via seven-transmembrane ... More
Regulatory role of CD4/L3T4 molecules in IL-2 production by affecting intracellular Ca2+ concentration of T cell clone stimulated with soluble anti-CD3.
AuthorsTamura T, Mizuguchi J, Nariuchi H
JournalJ Immunol
PubMed ID1972723
'To elucidate the role of CD4 molecule in T cell activation, the effect of anti-CD4 on T cell IL-2 production was examined by using an alloreactive Th clone. The alloreactive T cell used in the present experiments produced IL-2 in response to soluble anti-CD3 epsilon-chain (anti-CD3) without accessory cell or ... More
Actin depolymerization transduces the strength of B-cell receptor stimulation.
AuthorsHao S, August A
JournalMol Biol Cell
PubMed ID15728723
'Polymerization of the actin cytoskeleton has been found to be essential for B-cell activation. We show here, however, that stimulation of BCR induces a rapid global actin depolymerization in a BCR signal strength-dependent manner, followed by polarized actin repolymerization. Depolymerization of actin enhances and blocking actin depolymerization inhibits BCR signaling, ... More
Mast cell tryptase controls paracellular permeability of the intestine. Role of protease-activated receptor 2 and beta-arrestins.
'Tight junctions between intestinal epithelial cells prevent ingress of luminal macromolecules and bacteria and protect against inflammation and infection. During stress and inflammation, mast cells mediate increased mucosal permeability by unknown mechanisms. We hypothesized that mast cell tryptase cleaves protease-activated receptor 2 (PAR2) on colonocytes to increase paracellular permeability. Colonocytes ... More
Effects of substance P on [Ca2+]i and force in intact guinea pig ileal smooth muscle.
AuthorsMatthijs G, Himpens B, Peeters TL, Vantrappen G
JournalAm J Physiol
PubMed ID1695485
'In intact sheets of the guinea pig ileal longitudinal muscle, loaded with fura-2, both substance P (SP)- and K(+)-induced contractile responses are preceded by cytoplasmic free Ca2+ ([Ca2+]i) variations. In response to SP (10(-10)-10(-7) M), [Ca2+]i and force increased concentration dependently. From 10(-9) M on, the response was biphasic: an ... More
Excitatory amino acid-induced alterations of cytoplasmic free Ca2+ in individual cerebellar granule neurons: role in neurotoxicity.
AuthorsMilani D, Guidolin D, Facci L, Pozzan T, Buso M, Leon A, Skaper SD
JournalJ Neurosci Res
PubMed ID1677430
'The effects of glutamate on intracellular free Ca2+, [Ca2+]i, and neurotoxicity were compared in cerebellar granule neurons in vitro. [Ca2+]i was measured with fura-2 and digital fluorescence imaging microscopy; neurotoxicity was monitored using a vital dye and colorimetric analysis. Glutamate produced dose-dependent increases in [Ca2+]i, which tended to be transient ... More
Effects of lead, mercury, and methyl mercury on gap junctions and [Ca2+]i in bone cells.
AuthorsSchirrmacher K, Wiemann M, Bingmann D, Büsselberg D
JournalCalcif Tissue Int
PubMed ID9685518
'Heavy metals such as lead (Pb), mercury (Hg), and methyl mercury (MeHg) impair cell functions. For bone it is known that Pb changes bone formation rates, which depend on intracellular free calcium concentration ([Ca2+]i). Since heavy metals compete with Ca2+ at multiple sites and increased [Ca2+]i reduces gap junctional coupling ... More
Direct measurement of free Ca in organelles of gastric epithelial cells.
AuthorsHofer AM, Machen TE
JournalAm J Physiol
PubMed ID7943242
'When loaded as the acetoxymethyl ester (AM) derivative, the fluorescent probe mag-fura 2 accumulates in both the cytoplasm and the subcellular compartments. The relatively high dissociation constant of this dye for Ca (53 microM) permits the measurement of changes in the free concentration of this ion in a variety of ... More
Activation of endothelin ETA receptors induces phosphorylation of alpha1b-adrenoreceptors in Rat-1 fibroblasts.
AuthorsVázquez-Prado J, Medina LC, García-Sáinz JA
JournalJ Biol Chem
PubMed ID9341183
'The effect of endothelin-1 on the phosphorylation of alpha1b-adrenoreceptors, transfected into rat-1 fibroblasts, was studied. Basal alpha1b-adrenoreceptor phosphorylation was markedly increased by endothelin-1, norepinephrine, and phorbol esters. The effect of endothelin-1 was dose dependent (EC50 approximately 1 nM), reached its maximum 5 min after stimulation, and was inhibited by BQ-123, ... More
Changes in calcium signalling in dorsal horn neurons in rats with streptozotocin-induced diabetes.
'Intracellular calcium signalling was studied in the dorsal horn from neurons of rats with streptozotocin-induced diabetes versus control animals. The cytoplasmic Ca2+ concentration ([Ca2+]i) was measured in Fura-2 acetoxymethyl ester-loaded dorsal horn neurons from acutely isolated spinal cord slices using a fluorescence technique. The recovery of depolarization-induced [Ca2+]i increase was ... More
Calcium-sensing receptor regulation of PTH-dependent calcium absorption by mouse cortical ascending limbs.
AuthorsMotoyama HI, Friedman PA
JournalAm J Physiol Renal Physiol
PubMed ID12167589
'Resting Ca(2+) absorption by cortical thick ascending limbs (CALs) is passive and proceeds through the paracellular pathway. In contrast, parathyroid hormone (PTH) stimulates active, transcellular Ca(2+) absorption (J(Ca)). The Ca(2+)-sensing receptor (CaSR) is expressed on serosal membranes of CALs. In the present study, we tested the hypothesis that activation of ... More
Overall lack of regulated secretion in a PC12 variant cell clone.
AuthorsCorradi N, Borgonovo B, Clementi E, Bassetti M, Racchetti G, Consalez GG, Huttner WB, Meldolesi J, Rosa P
JournalJ Biol Chem
PubMed ID8900203
'A stable clone of PC12 neuroendocrine cells, named 27, known from previous studies to exhibit a defect of regulated secretion (lack of regulated secretory proteins, of synaptophysin, of dense granules and of catecholamine uptake and release; Clementi, E., Racchetti, G., Zacchetti, D., Panzeri, M. C., and Meldolesi, J. (1992) Eur. ... More
Knocking down type 2 but not type 1 calsequestrin reduces calcium sequestration and release in C2C12 skeletal muscle myotubes.
AuthorsWang Y, Xu L, Duan H, Pasek DA, Eu JP, Meissner G
JournalJ Biol Chem
PubMed ID16595676
'We examined the roles of type 1 and type 2 calsequestrins (CSQ1 and CSQ2) in stored Ca2+ release of C2C12 skeletal muscle myotubes. Transduction of C2C12 myoblasts with CSQ1 or CSQ2 small interfering RNAs effectively reduced the expression of targeted CSQ protein to near undetectable levels. As compared with control ... More
Extrusion of intracellular calcium ion after in vitro ischemia in the rat hippocampal CA1 region.
AuthorsTanaka E, Uchikado H, Niiyama S, Uematsu K, Higashi H
JournalJ Neurophysiol
PubMed ID12163539
'Simultaneous recordings of intracellular Ca(2+) ([Ca(2+)](i)) signal and extracellular DC potential were obtained from the CA1 region in 1-[6-amino-2-(5-carboxy-2-oxazolyl)-5-benzofuranyloxy]-2-(2-amino-5-methylphenoxy)-ethane-N,N,N',N'-tetraacetic acid penta-acetoxymethyl ester (Fura-2/AM)-loaded rat hippocampal slices. Superfusion with oxygen- and glucose-deprived medium (in vitro ischemia) for 5-6 min produced a rapid rise of the [Ca(2+)](i) level in the stratum radiatum ... More
The effects of substance P and carbachol on inositol tris- and tetrakisphosphate formation and cytosolic free calcium in rat parotid acinar cells. A correlation between inositol phosphate levels and calcium entry.
AuthorsMerritt JE, Rink TJ
JournalJ Biol Chem
PubMed ID2444592
'Both substance P and carbachol produced increases in inositol tris- and tetrakisphosphate and increased cytosolic free [Ca2+] in dispersed parotid acinar cells loaded with fura-2. The increase in [Ca2+]i in response to each agonist was due to a combination of mobilization of internal Ca2+ and entry of extracellular Ca2+. Kinetic ... More
Regional calcium regulation within cultured Drosophila neurons: effects of altered cAMP metabolism by the learning mutations dunce and rutabaga.
AuthorsBerke B, Wu CF
JournalJ Neurosci
PubMed ID12040051
'The dunce (dnc) and rutabaga (rut) mutations of Drosophila affect a cAMP-dependent phosphodiesterase and a Ca(2+)/CaM-regulated adenylyl cyclase, respectively. These mutations cause deficiencies in several learning paradigms and alter synaptic transmission, growth cone motility, and action potential generation. The cellular phenotypes either are Ca(2+) dependent (neurotransmission and motility) or mediate ... More
Spontaneous oscillations of intracellular calcium and growth hormone secretion.
'A novel combination of two single cell assays allowed the simultaneous measurement of intracellular calcium concentration and hormone secretion in normal pituitary cells. [Ca2+]i was recorded using the fluorescent Ca2+ indicator fura-2 and digital imaging microscopy. This technique was combined with a reverse hemolytic plaque assay for growth hormone in ... More
Long-term regulation of neuronal calcium currents by prolonged changes of membrane potential.
AuthorsFranklin JL, Fickbohm DJ, Willard AL
JournalJ Neurosci
PubMed ID1315850
'Although rapid-onset, short-term regulation of neuronal Ca currents by neurotransmitters and second messengers is well documented, little is known about conditions that can cause longer-lasting changes in Ca channel function. We report here that persistent depolarization is accompanied by slowly developing long-term reduction of neuronal Ca currents. Rat myenteric neurons ... More
Androgens increase intracellular calcium concentration and inositol 1,4,5-trisphosphate and diacylglycerol formation via a pertussis toxin-sensitive G-protein.
AuthorsLieberherr M, Grosse B
JournalJ Biol Chem
PubMed ID8125934
'Bone is a target tissue of androgens, but the mechanisms by which they act on bone are still unclear. This study examines the early (5-60 s) effects of 1 pM to 1 microM testosterone on cytosolic free Ca2+ concentration ([Ca2+]i) and inositol 1,4,5-trisphosphate (InsP3) and diacyglycerol (DAG) formation in confluent ... More
N-methyl-D-aspartate increases cytosolic Ca2+ via G proteins in cultured hippocampal neurons.
AuthorsHarada K, Yoshimura T, Nakajima K, Ito H, Ebina Y, Shingai R
JournalAm J Physiol
PubMed ID1314490
'The changes of the cytosolic Ca2+ concentrations ([Ca2+]i) induced by N-methyl-D-aspartate (NMDA) in fura-2-loaded cultured hippocampal neurons from rat embryos were investigated by the fast application method, using a fine pipe under extracellular Mg(2+)-free conditions. In the presence of Ca2+, NMDA, at concentrations in excess of 3 microM, induced a ... More
Tumor necrosis factor-alpha, sphingomyelinase, and ceramide inhibit store-operated calcium entry in thyroid FRTL-5 cells.
AuthorsTörnquist K, Malm AM, Pasternack M, Kronqvist R, Björklund S, Tuominen R, Slotte JP
JournalJ Biol Chem
PubMed ID10092616
'Tumor necrosis factor alpha (TNF-alpha) is a potent inhibitor of proliferation in several cell types, including thyroid FRTL-5 cells. As intracellular free calcium ([Ca2+]i) is a major signal in activating proliferation, we investigated the effect of TNF-alpha on calcium fluxes in FRTL-5 cells. TNF-alpha per se did not modulate resting ... More
Na+-dependent release of Mg2+ from an intracellular pool in rat sublingual mucous acini.
AuthorsZhang GH, Melvin JE
JournalJ Biol Chem
PubMed ID8910560
'Muscarinic stimulation induces release of Mg2+ from an intracellular pool in rat sublingual mucous acini (Zhang, G. H., and Melvin, J. E. (1992) J. Biol. Chem. 267, 20721-20727). In the present study we examined the interdependence of Mg2+ mobilization on intracellular Na+ and Ca2+ by monitoring the intracellular free concentrations ... More
Cumene hydroperoxide induced changes in calcium homeostasis in cultured neonatal rat heart cells.
AuthorsPersoon-Rothert M, Egas-Kenniphaas JM, van der Valk-Kokshoorn EJ, van der Laarse A
JournalCardiovasc Res
PubMed ID1423436
'OBJECTIVE: The relationship between oxidative stress induced cell necrosis and perturbation of intracellular calcium homeostasis was investigated in cultured myocytes. METHODS: Cultured neonatal rat heart cells were loaded with fura-2 AM to measure cytosolic free calcium ([Ca2+]i). Probenecid, an inhibitor of organic anion transport, was present during the experiment to ... More
Protective effects of antioxidative serotonin derivatives isolated from safflower against postischemic myocardial dysfunction.
AuthorsHotta Y, Nagatsu A, Liu W, Muto T, Narumiya C, Lu X, Yajima M, Ishikawa N, Miyazeki K, Kawai N, Mizukami H, Sakakibara J
JournalMol Cell Biochem
PubMed ID12349903
'N-(p-Coumaroyl)serotonin (C) and N-feruroylserotonin (F) with antioxidative activity are present in safflower oil. The protective effects of C and F were investigated in perfused guinea-pig Langendorff hearts subjected to ischemia and reperfusion. Changes in cellular levels of high phosphorous energy, NO and Ca2+ in the heart together with simultaneous recordings ... More
Ca2+ influx does more than provide releasable Ca2+ to maintain repetitive spiking in human umbilical vein endothelial cells.
AuthorsMorgan AJ, Jacob R
JournalBiochem J
PubMed ID8973560
'We investigated why oscillations of intracellular Ca2+ concentrations ([Ca2+]i) in endothelial cells challenged by sub-maximal histamine run down in Ca(2+)-free medium despite stores retaining most of their Ca2+. One explantation is that only a small subpopulation of the Ca2+ stores oscillate and are completely emptied of Ca2+. To investigate if ... More
Muscarinic acetylcholine receptor-mediated induction of zif268 mRNA in PC12D cells requires protein kinase C and the influx of extracellular calcium.
AuthorsEbihara T, Saffen D
JournalJ Neurochem
PubMed ID9048745
'The immediate-early gene zif268 (egr-1, NGFI-A, krox-24) encodes a transcription factor that has been proposed to play a role in differentiation and neuronal plasticity. zif268 mRNA is undetectable in unstimulated PC12D cells, a subline of PC12 characterized by accelerated differentiation in the presence of nerve growth factor, but is rapidly ... More
Evidence for the existence of inositol (1,4,5)-trisphosphate- and ryanodine-sensitive pools in bovine endothelial cells. Ca2+ releases in cells with different basal level of intracellular Ca2+.
AuthorsMozhayeva MG, Mozhayeva GN
JournalPflugers Arch
PubMed ID8764961
'In single bovine aortic endothelial (BAE) cells pre-loaded with Fura-2, Ca2+ transients in a Ca2+-free medium have been revealed, which evidently reflects Ca2+ release from intracellular stores. In cells with different levels of resting basal cytoplasmic Ca2+ ([Ca2+]i) from about 50 to 110 nM, a biphasic dependence of the Ca2+ ... More
Modulation of vincristine sensitivity of human kidney tumor cells by pharmacological agents interfering with intracellular signals. No apparent relationship to changes in cytoplasmic Ca2+ or pH.
AuthorsNygren P, Larsson R
JournalBiochim Biophys Acta
PubMed ID2191723
'The effect of substances proposed to modulate intracellular signal systems on growth and sensitivity to vincristine in the human kidney tumor cell line ACHN was investigated and related to changes in cytoplasmic free Ca2+ concentration ([Ca2+]i) and cytoplasmic pH (pHi). Presence during culture of the protein kinase C (PKC) activator ... More
Effects of inorganic and organic mercury on intracellular calcium levels in rat T lymphocytes.
AuthorsTan XX, Tang C, Castoldi AF, Manzo L, Costa LG
JournalJ Toxicol Environ Health
PubMed ID8433400
'The importance of cytosolic free calcium level ([Ca2+]i) in lymphocyte activation prompted us to investigate changes in [Ca2+]i in T cells caused by mercury compounds, which have been shown to have immunomodulatory and immunotoxic properties. Using fura-2 as fluorescent Ca2+ indicator, we found that both methyl-mercury (MeHg; 0.02-2 microM) and ... More
Flow-induced changes in Ca2+ signaling of vascular endothelial cells: effect of shear stress and ATP.
AuthorsMo M, Eskin SG, Schilling WP
JournalAm J Physiol
PubMed ID2035689
'The effect of hemodynamic flow on apparent cytosolic free Ca2+ concentration ([Ca2+]i) of cultured bovine aortic endothelial cells was examined in the absence and presence of adenine nucleotides using microfluorimetric analysis of fura-2 fluorescence. In the absence of adenine nucleotides, flow-induced shear stress produced little change (less than 10 nM) ... More
Enhanced [Ca2+]i in renal arterial smooth muscle cells of pregnant rats with reduced uterine perfusion pressure.
AuthorsMurphy JG, Herrington JN, Granger JP, Khalil RA
JournalAm J Physiol Heart Circ Physiol
PubMed ID12388289
'Reduction of uterine perfusion pressure (RUPP) during late pregnancy has been suggested to trigger increases in renal vascular resistance and lead to hypertension of pregnancy. We investigated whether the increased renal vascular resistance associated with RUPP in late pregnancy reflects increases in intracellular Ca(2+) concentration ([Ca(2+)](i)) and contraction of renal ... More