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
Presynaptic calcium signals and transmitter release are modulated by calcium-activated potassium channels.
AuthorsRobitaille R, Charlton MP
JournalJ Neurosci
PubMed ID1370323
'The regulation of synaptic transmission by Ca(2+)-activated potassium (gKca) channels was investigated at the frog neuromuscular junction (nmj). Charybdotoxin (CTX), a blocker of certain types of gKca channels, induced a twofold increase of transmitter release. Similar results were obtained with purified natural toxin, synthetic toxin, and recombinant toxin. Apamin, a ... More
Intracellular free Ca2+ in the cell cycle in human fibroblasts: transitions between G1 and G0 and progression into S phase.
AuthorsWahl M, Gruenstein E
JournalMol Biol Cell
PubMed ID8485320
'Intracellular free calcium ([Ca2+]i) has been proposed to play an important part in the regulation of the cell cycle. Although a number of studies have shown that stimulation of quiescent cells with growth factors causes an immediate rise in [Ca2+]i (Rabinovitch et al., 1986; Vincentini and Villereal, 1986; Hesketh et ... More
Arginine vasopressin stimulates H+-ATPase in MDCK cells via V1 (cell Ca2+) and V2 (cAMP) receptors.
AuthorsOliveira-Souza M, Musa-Aziz R, Malnic G, De Mello Aires M
JournalAm J Physiol Renal Physiol
PubMed ID12965889
'The effect of arginine vasopressin (AVP) and/or atrial natriuretic peptide (ANP) on the regulation of intracellular pH (pHi) via H+-ATPase and of cytosolic calcium ([Ca2+]i) was investigated in Madin-Darby canine kidney (MDCK) cells by the fluorescent probes BCECF-AM and fluo-4-AM, respectively. The pHi recovery rate was examined after intracellular acidification ... More
Calcium regulates the association between mitochondria and a smooth subdomain of the endoplasmic reticulum.
AuthorsWang HJ, Guay G, Pogan L, Sauvé R, Nabi IR
JournalJ Cell Biol
PubMed ID10995452
'Association between the ER and mitochondria has long been observed, and the formation of close contacts between ER and mitochondria is necessary for the ER-mediated sequestration of cytosolic calcium by mitochondria. Autocrine motility factor receptor (AMF-R) is a marker for a smooth subdomain of the ER, shown here by confocal ... More
Functional colocalization of calcium and calcium-gated potassium channels in control of transmitter release.
'We examined, using physiological and morphological techniques, the distribution of Ca(2+)-gated K+ (gKca) channels relative to the location of Ca2+ channels and transmitter release sites at the frog neuromuscular junction (NM). Charybdotoxin (ChTx) and iberiotoxin, blockers of gKca channels with large conductances, increase transmitter release at the frog NMJ. Intracellular ... More
Local positive feedback by calcium in the propagation of intracellular calcium waves.
AuthorsWang SS, Thompson SH
JournalBiophys J
PubMed ID8580312
'In many types of eukaryotic cells, the activation of surface receptors leads to the production of inositol 1,4,5-trisphosphate and calcium release from intracellular stores. Calcium release can occur in complex spatial patterns, including waves of release that traverse the cytoplasm. Fluorescence video microscopy was used to view calcium waves in ... More
Improvement of insulin sensitivity by chelation of intracellular Ca(2+) in high-fat-fed rats.
AuthorsJang YJ, Ryu HJ, Choi YO, Kim C, Leem CH, Park CS
JournalMetabolism
PubMed ID12077741
'It has been postulated that sustained high levels of intracellular calcium concentration ([Ca(2+)](i)) in the insulin target cells may cause insulin resistance. We evaluated this hypothesis by examining the effect of an intracellular Ca(2+) chelator, 5,5'-dimethyl derivative of bis (o-aminophenoxy) ethane-N,N,N',N' tetraacetic acetoxymethyl ester (dimethyl-BAPTA/AM), on insulin resistance. Insulin resistance ... More
Exocytosis of a subpopulation of specific granules coincides with H2O2 production in adherent human neutrophils.
AuthorsSuchard SJ, Boxer LA
JournalJ Immunol
PubMed ID8254197
'Unlike polymorphonuclear leukocytes (PMN) that are activated in suspension, PMN plated onto extracellular matrix (ECM) proteins exhibited a prolonged delay in the onset of the respiratory burst in response to PMA, FMLP, A23187, or GM-CSF. The present study was focused on examining the events leading to H2O2 release in adherent ... More
Overexpression of potassium channel RNA: in vivo development rescues neurons from suppression of morphological differentiation in vitro.
AuthorsJones SM, Hofmann AD, Lieber JL, Ribera AB
JournalJ Neurosci
PubMed ID7722635
'Neuronal differentiation often proceeds differently in vitro than it does in vivo. Previous work demonstrated that overexpression of potassium channel RNA reduces the number of morphologically identifiable neurons that appear in cultures prepared from neural plate stage (17-1/2 hr) embryos (Jones and Ribera, 1994). Here, we report that morphological differentiation ... More
Involvement of intracellular or extracellular calcium in activation of tyrosine hydroxylase gene expression in PC12 cells.
AuthorsMenezes A, Zeman R, Sabban E
JournalJ Neurochem
PubMed ID8931463
'The relationship between elevations in intracellular free Ca2+ concentration ([Ca2+]i) by different mechanisms and tyrosine hydroxylase (TH) gene expression was examined. Depolarization by an elevated K+ concentration triggered rapid and sustained increases in [Ca2+]i from a basal level of approximately 50 to 110-150 nM and three- to fourfold elevations in ... More
Inhibitors of protein phosphatase type 1 and 2A attenuate phosphatidylinositol metabolism and Ca(2+)-transients in human platelets. Role of a cdc2-related protein kinase.
AuthorsLerea KM
JournalBiochemistry
PubMed ID1321663
'The addition of either okadaic acid or calyculin A desensitizes human platelets to thrombin. One objective of this study was to determine which step(s) leading to secretion reactions may be affected by these protein phosphatase inhibitors. In a dose-dependent manner, okadaic acid or calyculin A inhibits phosphatidylinositol metabolism and Ca(2+)-transients. ... More
Calcium oscillations and morphological transformations in single cultured gastric parietal cells.
AuthorsLjungström M, Chew CS
JournalAm J Physiol
PubMed ID1822116
'Calcium is an important regulator of cellular activities including HCl secretion by parietal cells. With cholinergic agonists, a role for calcium is established; however, with histamine, at least two signaling pathways may be involved including calcium and adenosine 3',5'-cyclic monophosphate (cAMP). Because chelation of medium and/or cellular calcium has pronounced ... More
Ionophore A23187-induced protein-tyrosine phosphorylation of human platelets: possible synergism between Ca2+ mobilization and protein kinase C activation.
'Addition of ionophore A23187 to washed human platelets caused a time- and dose-dependent increase in the phosphotyrosyl content of 135, 124 and 76 kDa proteins. Platelets loaded with intracellular Ca2+ chelator 5,5''-dimethyl-bis-(o-aminophenoxy)-ethane-N, N, N'', N''-tetraacetic acid before addition of A23187 exhibited no protein-tyrosine phosphorylation. Replenishment of such platelets with extracellular ... More
ICAM-1-coupled cytoskeletal rearrangements and transendothelial lymphocyte migration involve intracellular calcium signaling in brain endothelial cell lines.
'Endothelium of the cerebral blood vessels, which constitutes the blood-brain barrier, controls adhesion and trafficking of leukocytes into the brain. Investigating signaling pathways triggered by the engagement of adhesion molecules expressed on brain endothelial cells using two rat brain endothelial cell lines (RBE4 and GP8), we report in this paper ... More
Calcium store depletion in dimethyl BAPTA-loaded human platelets increases protein tyrosine phosphorylation in the absence of a rise in cytosolic calcium.
AuthorsSargeant P, Farndale RW, Sage SO
JournalExp Physiol
PubMed ID8003312
The endomembrane Ca(2+)-ATPase inhibitor, thapsigargin, was used to deplete the intracellular Ca2+ stores of fura-2-loaded human platelets. In control cells, thapsigargin evoked a rise in cytosolic [Ca2+] and a substantial increase in protein tyrosine phosphorylation. Thapsigargin also evoked an increase in tyrosine phosphorylation in cells co-loaded with fura-2 and the ... More
Calcium-independent cytoskeleton disassembly induced by BAPTA.
AuthorsSaoudi Y, Rousseau B, Doussière J, Charrasse S, Gauthier-Rouvière C, Morin N, Sautet-Laugier C, Denarier E, Scaïfe R, Mioskowski C, Job D,
JournalEur J Biochem
PubMed ID15265045
In living organisms, Ca2+ signalling is central to cell physiology. The Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) has been widely used as a probe to test the role of calcium in a large variety of cell functions. Here we show that in most cell types BAPTA has a potent actin and ... More
P/Q-type calcium channels activate neighboring calcium-dependent potassium channels in mouse motor nerve terminals.
AuthorsProtti DA, Uchitel OD
JournalPflugers Arch
PubMed ID9211806
The identity of the voltage-dependent calcium channels (VDCC), which trigger the Ca2+-gated K+ currents (IK(Ca)) in mammalian motor nerve terminals, was investigated by means of perineurial recordings. The effects of Ca2+ chelators with different binding kinetics on the activation of IK(Ca) were also examined. The calcium channel blockers of the ... More
A fluorescence technique to distinguish attached from ingested erythrocytes and zymosan particles in phagocytosing macrophages.
AuthorsGreenberg S, el Khoury J, Kaplan E, Silverstein SC
JournalJ Immunol Methods
PubMed ID2040809
While investigating the role of [Ca2+]i in Fc receptor-mediated phagocytosis, we found that clamping the [Ca2+]i to low levels by a variety of methods often led to increased plasma membrane permeability, rendering the hypotonic lysis method for calculating the phagocytosis index unreliable. To overcome this difficulty we developed a method ... More
ATP stimulates human macrophages to kill intracellular virulent Mycobacterium tuberculosis via calcium-dependent phagosome-lysosome fusion.
AuthorsKusner DJ, Barton JA
JournalJ Immunol
PubMed ID11544319
Advances in therapy for tuberculosis will require greater understanding of the molecular mechanisms of pathogenesis and the human immune response in this disease. Exposure of Mycobacterium tuberculosis-infected human macrophages to extracellular ATP (ATP(e)) results in bacterial killing, but the molecular mechanisms remain incompletely characterized. In this study, we demonstrate that ... More
Vasopressin-stimulated electrogenic sodium transport in A6 cells is linked to a Ca(2+)-mobilizing signal mechanism.
AuthorsHayslett JP, Macala LJ, Smallwood JI, Kalghatgi L, Gassala-Herraiz J, Isales C
JournalJ Biol Chem
PubMed ID7608170
Vasopressin is known to activate two types of cell surface receptors; V2, coupled to adenylate cyclase, and V1, linked to a Ca(2+)-dependent transduction system. We investigated whether arginine vasopressin (AVP) stimulation of electrogenic sodium transport in A6 cells, derived from Xenopus laevis, is mediated by activation of either one or ... More
Rapid ultrastructural changes in the dense tubular system following platelet activation.
AuthorsEbbeling L, Robertson C, McNicol A, Gerrard JM
JournalBlood
PubMed ID1322202
The dense tubular system (DTS) functions to regulate platelet activation by sequestering or releasing calcium, similar to the sarcotubules of skeletal muscle. In resting platelets, the DTS exists as thin elongated membranes. Within 10 seconds of the addition of thrombin, platelets show a major ultrastructural change in their DTS: from ... More
L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals.
AuthorsUrbano FJ, Uchitel OD
JournalPflugers Arch
PubMed ID10089564
The involvement of the different types of voltage-dependent calcium channels (VDCC) in both DM-BAPTA-AM-incubated and EGTA-AM-incubated mature mice levator auris neuromuscular junctions (NMJ) was studied. We evaluated the effects of omega-agatoxin IVA (omega-Aga IVA), nitrendipine and omega-conotoxin GVIA (omega-CgTX) (P/Q-, L- and N-type VDCC blockers, respectively) on perineurial calcium currents ... More
Role of the ERK pathway in the activation of store-mediated calcium entry in human platelets.
AuthorsRosado JA, Sage SO
JournalJ Biol Chem
PubMed ID11278479
Extracellular signal-regulated kinases (ERKs), are common participants in a broad variety of signal transduction pathways. Several studies have demonstrated the presence of ERKs in human platelets and their activation by the physiological agonist thrombin. Here we report the involvement of the ERK cascade in store-mediated Ca(2+) entry in human platelets. ... More
Atrial natriuretic peptide impairs the stimulatory effect of angiotensin II on H+-ATPase.
AuthorsOliveira-Souza M, Malnic G, Mello-Aires M
JournalKidney Int
PubMed ID12371969
BACKGROUND: Angiotensin II (Ang II) action on H+-ATPase is not clearly defined, and may vary with renal tubule segment and hormonal doses being studied. Since an increase of cytosolic calcium ([Ca2+]i) can stimulate acid vesicle movement and exocytotic insertion of proton pumps, and it has been shown that Ang II ... More
Physiological [Ca2+]i level and pump-leak turnover in intact red cells measured using an incorporated Ca chelator.
AuthorsLew VL, Tsien RY, Miner C, Bookchin RM
JournalNature
PubMed ID6283392
The physiological actions of Ca2+ as a trigger and second messenger depend on the maintenance of large inward resting Ca2+ gradients across the cell plasma membrane. An ATP-fuelled Ca-pump, originally discovered and still best characterized in human red cells, is now believed to mediate resting Ca2+ extrusion in most animal ... More
Synergistic adhesive interactions and signaling mechanisms operating between platelet glycoprotein Ib/IX and integrin alpha IIbbeta 3. Studies in human platelets ans transfected Chinese hamster ovary cells.
AuthorsYap CL, Hughan SC, Cranmer SL, Nesbitt WS, Rooney MM, Giuliano S, Kulkarni S, Dopheide SM, Yuan Y, Salem HH, Jackson SP
JournalJ Biol Chem
PubMed ID10967111
This study investigates three aspects of the adhesive interaction operating between platelet glycoprotein Ib/IX and integrin alpha(IIb)beta(3). These include the following: 1) examining the sufficiency of GPIb/IX and integrin alpha(IIb)beta(3) to mediate irreversible cell adhesion on immobilized von Willebrand factor (vWf) under flow; 2) the ability of the vWf-GPIb interaction ... More
Involvement of protein-tyrosine kinase p72syk in collagen-induced signal transduction in platelets.
AuthorsFujii C, Yanagi S, Sada K, Nagai K, Taniguchi T, Yamamura H
JournalEur J Biochem
PubMed ID7957255
Previous studies have demonstrated that activation of platelets by collagen results in a dramatic increase in tyrosine phosphorylation of several cellular proteins, including pp125FAK, through the interaction of collagen with integrin alpha 2 beta 1 (GP Ia-IIa). In this study, we report that p72syk is a potential candidate for the ... More
Platelet shape change is mediated by both calcium-dependent and -independent signaling pathways. Role of p160 Rho-associated coiled-coil-containing protein kinase in platelet shape change.
AuthorsPaul BZ, Daniel JL, Kunapuli SP
JournalJ Biol Chem
PubMed ID10497186
Platelets undergo shape change upon activation with agonists. During shape change, disc-shaped platelets turn into spiculated spheres with protruding filopodia. When agonist-induced cytosolic Ca(2+) increases were prevented using the cytosolic Ca(2+) chelator, 5, 5'-dimethyl-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (5, 5'-dimethyl-BAPTA), platelets still underwent shape change, although the onset was delayed and the initial ... More
Cyclic nucleotides modulate store-mediated calcium entry through the activation of protein-tyrosine phosphatases and altered actin polymerization in human platelets.
AuthorsRosado JA, Porras T, Conde M, Sage SO
JournalJ Biol Chem
PubMed ID11278478
Agonists elevate the cytosolic calcium concentration in human platelets via a receptor-operated mechanism, involving both Ca(2+) release from intracellular stores and subsequent Ca(2+) entry, which can be inhibited by platelet inhibitors, such as prostaglandin E(1) and nitroprusside which elevate cAMP and cGMP, respectively. In the present study we investigated the ... More
Transcriptional induction of CYP1A1 by oltipraz in human Caco-2 cells is aryl hydrocarbon receptor- and calcium-dependent.
AuthorsLe Ferrec E, Lagadic-Gossmann D, Rauch C, Bardiau C, Maheo K, Massiere F, Le Vee M, Guillouzo A, Morel F
JournalJ Biol Chem
PubMed ID11959854
Oltipraz, a synthetic derivative of the cruciferous vegetable product 1,2-dithiole-3-thione, is considered as one of the most potent chemoprotectants. It modulates both cytochrome P-450 (CYP) and glutathione S-transferase expression and activities in rat tissues. Its effects, however, are variable according to the enzyme, tissue, and species. We show here that, ... More
Intracellular calcium mobilization and activation of the Na+/H+ exchanger in platelets.
AuthorsPoch E, Botey A, Gaya J, Cases A, Rivera F, Revert L
JournalBiochem J
PubMed ID8383969
The aim of the present study was to evaluate the regulatory relationship between the cytosolic free calcium concentration ([Ca2+]i and cytosolic pH (pHi). [Ca2+]i and pHi were measured using the fluorescent dyes fura-2 and BCECF [2',7'-bis-(carboxyethyl)-5,6-carboxyfluorescein] respectively. In a medium with 1 mmol/l extracellular calcium, thrombin (2.5 units/ml) induced an ... More
Apoptosis induced by withdrawal of interleukin-3 (IL-3) from an IL-3-dependent hematopoietic cell line is associated with repartitioning of intracellular calcium and is blocked by enforced Bcl-2 oncoprotein production.
The regulation of intracellular pools of Ca2+ was investigated in an interleukin-3 (IL-3)-dependent hematopoietic cell line 32D that undergoes programmed cell death ("apoptosis") when deprived of lymphokine. Comparisons were made with 32D cells that had been stably transfected with a bcl-2 expression plasmid that encodes a 26-kDa intracellular integral-membrane protein ... More
Sodium-evoked, calcium-independent vasopressin release from rat isolated neurohypophysial nerve endings.
AuthorsStuenkel EL, Nordmann JJ
JournalJ Physiol
PubMed ID7504728
1. The effects of Na+ on vasopressin release and on redistribution of Ca2+, Na+ and H+ in isolated rat neurohypophysial nerve endings have been studied. 2. Substituting Na+ for a non-permanent cation produced a pronounced and sustained release of vasopressin. This increase occurred in the absence of external Ca2+ and ... More
The exit of mouse oocytes from meiotic M-phase requires an intact spindle during intracellular calcium release.
AuthorsWinston NJ, McGuinness O, Johnson MH, Maro B
JournalJ Cell Sci
PubMed ID7738091
To study the role of the metaphase spindle during the period of oocyte activation, mouse oocytes were fertilised or activated parthenogenetically in the presence or absence of the microtubule inhibitor nocodazole. In both cases, nocodazole caused the disappearance of the spindle and prevented the passage of the oocytes into interphase. ... More
Coupling between intracellular Ca2+ stores and the Ca2+ permeability of the plasma membrane. Comparison of the effects of thapsigargin, 2,5-di-(tert-butyl)-1,4-hydroquinone, and cyclopiazonic acid in rat thymic lymphocytes.
AuthorsMason MJ, Garcia-Rodriguez C, Grinstein S
JournalJ Biol Chem
PubMed ID1834651
The regulation of Ca2+ uptake by receptors is incompletely understood. It has been proposed that the Ca2+ permeability of the plasma membrane increases in response to depletion of a critical intracellular Ca2+ storage compartment (Takemura, H., Hughes, A. R., Thastrup, O., and Putney, J. W. (1989) J. Biol. Chem. 264, ... More
Effect of arginine vasopressin and ANP on intracellular pH and cytosolic free [Ca2+] regulation in MDCK cells.
AuthorsOliveira-Souza M, Mello-Aires M
JournalKidney Int
PubMed ID11703598
BACKGROUND: The effects of arginine vasopressin (AVP) on intracellular pH (pHi) are not clearly defined, and may vary with cell membrane surface and the hormonal doses being studied. Since cytosolic free calcium concentration ([Ca2+]i) has an important effect on cellular H+ extrusion and it was shown that AVP increases [Ca2+]i ... More
Protein-tyrosine kinase p72syk is activated by thrombin and is negatively regulated through Ca2+ mobilization in platelets.
AuthorsTaniguchi T, Kitagawa H, Yasue S, Yanagi S, Sakai K, Asahi M, Ohta S, Takeuchi F, Nakamura S, Yamamura H
JournalJ Biol Chem
PubMed ID8428900
Activation of platelets by thrombin results in a dramatic increase in tyrosine phosphorylation on multiple cellular proteins (Ferrell, J. E., and Martin, G. S. (1988) Mol. Cell. Biol. 8, 3603-3610; Golden, A., and Brugge, J. S. (1989) Proc. Natl. Acad. Sci. U. S. A. 86, 901-905; Nakamura, S., and Yamamura, ... More
PAR-1-stimulated factor IXa binding to a small platelet subpopulation requires a pronounced and sustained increase of cytoplasmic calcium.
AuthorsLondon FS, Marcinkiewicz M, Walsh PN
JournalBiochemistry
PubMed ID16752917
We previously reported that only a subpopulation of PAR-1-stimulated platelets binds coagulation factor IXa, since confirmed by other laboratories. Since calcium changes have been implicated in exposure of procoagulant aminophospholipids, we have now examined calcium fluxes in this subpopulation by measuring fluorescence changes in Fura Red/AM-loaded platelets following PAR-1 stimulation. ... More