Intracellular calcium release at fertilization in the sea urchin egg

Steinhardt, Richard A.; Zucker, Robert S.; Schatten, Gerald

doi:10.1016/0012-1606(77)90084-7

Cited by 503 publications

(204 citation statements)

References 20 publications

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“…This regulation may work in some of Ca 2ϩ -mediated alterations in the actin cytoskeleton. For example, sea urchin eggs show the elongation of fascin-containing microvilli on the surface upon fertilization (7,42). Because fertilization is accompanied by an increase in Ca 2ϩ concentration, it is possible that a calmodulin-caldesmon-TM system is involved in the formation of fascin-actin bundles of microvilli, although caldesmon has not yet been identified in sea urchin eggs.…”

Section: Discussionmentioning

confidence: 99%

Regulation of Actin Binding and Actin Bundling Activities of Fascin by Caldesmon Coupled with Tropomyosin

Ishikawa¹,

Yamashiro²,

Kohama³

et al. 1998

Journal of Biological Chemistry

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Human fascin is an actin-bundling protein and is thought to play a role in the formation of microfilament bundles of microspikes and stress fibers in cultured cells. To explore the regulation of fascin-actin interaction, we have examined the effects of culture cell caldesmon and tropomyosin (TM) on actin binding activity of human fascin. Caldesmon alone or TM alone has little or no effect on the actin binding of fascin. However, caldesmon together with TM completely inhibits actin binding of human fascin. When calmodulin is added, the inhibition of fascin-actin interaction by caldesmon and TM becomes Ca 2؉ dependent because Ca 2؉ /calmodulin blocks actin binding of caldesmon. Furthermore, as phosphorylation of caldesmon by cdc2 kinase inhibits actin binding of caldesmon, phosphorylation can also control actin binding of fascin in the presence of TM. As expected by the inhibition of fascin-actin binding, caldesmon coupled with TM also inhibits actin bundling activity of fascin. Whereas smooth muscle caldesmon alone or TM alone shows no effect, caldesmon together with TM completely inhibits actin bundling activity of fascin. This inhibition is again Ca 2؉ dependent when calmodulin is added to the system. These results suggest important roles for caldesmon and TM in the regulation of the function of human fascin.Fascins belong to a unique family of actin-bundling proteins (1, 2), which include sea urchin fascin (3-8), HeLa 55-kDa actin-bundling protein (9, 10), and the gene products of Drosophila singed (11-13). All of these proteins make F-actin aggregate side-by-side into bundles (4, 8 -10) and are localized in the structures containing actin bundles including filopodia and stress fibers of cultured cells (1, 9, 10, 14), bristles of Drosophila, actin bundles of Drosophila nurse cells (11, 13), and microspikes and microvilli of sea urchin eggs and coelomocytes (6, 7). Some of these structures such as filopodia and microspikes are known to be dynamic structures responding to various biological signals. For example, the fertilization of sea urchin eggs induces the formation of fascin-containing microvilli on their surfaces (7). Filopodia contain fascin-actin bundles and are actively extending and retracting during cell movement of fibroblasts. Fascin should thus be involved in the assembly and disassembly of actin bundles in such structures. However, the mechanisms for the regulation of actin binding of fascin are not well understood.One way to regulate fascin-actin interaction is phosphorylation. We have shown that human fascin is phosphorylated at Ser-39 in vivo in human neuroblastoma cells upon treatment with 12-O-tetradecanoylphorbal-13-acetate, a tumor promoter (16). The same site is phosphorylated by protein kinase C, which results in the inhibition of actin binding of fascin (16,17). However, the stoichiometry of fascin phosphorylation by protein kinase C is low, suggesting that kinases other than protein kinase C may be involved. Furthermore, the stoichiometry of in vivo phosphorylation is also low in the a...

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Section: Discussionmentioning

confidence: 99%

Regulation of Actin Binding and Actin Bundling Activities of Fascin by Caldesmon Coupled with Tropomyosin

Ishikawa¹,

Yamashiro²,

Kohama³

et al. 1998

Journal of Biological Chemistry

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“…In addition 5 mM glucose (---) enhanced the LDCL comparably to 50-100 pM NADPH, indicating that NADPH is the substrate for the observed LDCL and that in freshly isolated eosinophils the hexose-monophosphate shunt activity is still sufficient. a-Toxin alone or NADPH or glucose added to permeabilized cells did not activate any LDCL (--- [16]). In order to equilibrate the cells with luminol, they were incubated for 4 min at 37"C, then 5 p1 a-toxin solution (1000 HU/ml) was added followed by a further 2-min incubation to allow permeabilization.…”

Section: Luminol-dependent Chemiluminescence (Ldcl)mentioning

confidence: 98%

“…equilibration by the Ca'+-sensitive fluoroscent substance fura-21 AM. Extracellular free [Ca"] was buffered with EGTA and the concentration was calculated with the equilibrium constants of Steinhardt et al [16]. At an extracellular free [Ca"] of 450 nM, permeabilization of 90% eosinophils or neutrophils was completed by an a-toxin concentration of 15 pHU/ cell after 2 min ( 9 2 5 6 % ( P = 0.95, n = 3), neutrophils 93 2 4 % ( P = 0.95,…”

Section: Eosinophil and Neutrophil Permeabilization With S Aureus A-mentioning

confidence: 99%

Nanomolar arachidonic acid influences the respiratory burst in eosinophils and neutrophils induced by GTP‐binding protein

Aebischer

Pasche

Jörg

1993

European Journal of Biochemistry

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To investigate a possible role of phospholipase A, (PLA,) in the respiratory burst in bovine eosinophilic and neutrophilic leukocytes dependent on GTP-binding protein (G-protein), we permeabilized these cells with Staphylococcus aureus a-toxin and induced NADPH oxidase activity with the non-hydrolysable GTP analogue GTP [S] or the aluminium tetrafluoro complex AlF,-. Under same experimental conditions, cells responded with different onset times. The onset time for eosinophils was 50-200 s, for neutrophils it was only a few seconds. GTP[S] stimulated in neutrophils only 5 % of the respiratory burst compared to eosinophils, whereas AlF,--induced comparable responses (neutrophils 120% of eosinophils). GDP inhibited these responses with an IC,, value of 2.4 mM. Arachidonic acid showed, with the exception of AIF,-stimulated neutrophils, on both stimuli and cell types an enhancing effect (150%) that reached its maximum at 0.1-1 pM. The PLA, inhibitor 4-bromophenacylbromide reduced the GTP[S]-and AlF,--induced response almost completely (10 pM) and the inhibition was not significantly different for eosinophils and neutrophils (IC50 1 -3 pM). If the respiratory burst was reduced with 4-bromophenacylbromide to 1 -4% of the original value, 10% of the basal NADPH oxidase activity could be restored by addition of only 20-100 nM arachidonic acid. In addition, the PLA, activator adriamycin enhanced the response in a dose-dependent manner and in the same order as arachidonic acid did. The results presented above suggest that the respiratory burst may be regulated by different low-molecular-mass and/or heterotrimeric G-proteins and an active role for arachidonic acid or its metabolites in the activation and the maintenance of the direct G-protein-stimulated respiratory burst in bovine eosinophils and neutrophils.When stimulated by particulate or soluble stimuli like opsonized zymosan, formyl-methionyl-leucyl-phenylalanine, leuktriene B,, platelet-activating factor or the anaphylatoxine C,a, phagocytes of the immune system generate superoxide (O;-) and other reduced oxygen species by using an NADPH oxidase, for reviews, see [l -31. of Fribourg, me du mussCe 5 , CH-1700 Fribourg, Switzerland cytosolic factors p47ph0" and p67ph"", the small G-protein p21r"'1'2 and an associated GDP dissociation inhibitor that have been identified as components of the activating mechanism at least in the cell-free system [4-61.The phosphorylation of several proteins has been reported. The phosphorylation of the p47phoX occurs in normal cells but has been reported to be absent in patients with autosomal recessive chronic granulomatous disease 171. There have been reports suggesting that phospholipase A, (PLA,) is involved in the activation of the respiratory burst oxidase. An increase in PLA, activity and a release of arachidonic acid has been shown to occur following the stimulation of NADPH oxidase by different stimuli in neutrophils as well as in macrophages [8-101. Quinacrine and 4-bromophenacylbromide, inhibitors of PLA,, have previously be...

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“…The surface of unfertilized sea urchin eggs is covered with numerous microvilli that abruptly elongate after fertilization (Schroeder, 1978). Increase in intracellular Ca2+ level (Steinhardt et al, 1977) or pH level (Mazia et al, 1975) following fertilization is believed to induce actin polymerization necessary for cytoskeletal extension in the process (Schroeder, 1978;Begg and Rebhun, 1979). The sperm acrosome also elongates very rapidly (> 50 pm/set), and this elongation is mediated by polymerization of highly organized microfilaments (Tilney et al, 1978;Tilney and Inoue, 1982).…”

Section: Dependence On Ca2+mentioning

confidence: 99%

Rapid sprouting of filopodia in nerve terminals of chromaffin cells, PC12 cells, and dorsal root neurons induced by electrical stimulation

Manivannan

Terakawa

1994

J. Neurosci.

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Rapid morphological changes induced by direct electrical stimulation of nerve terminals were studied by using video-enhanced differential interference contrast microscopy at a very high magnification (12,000x). We used mainly cultured bovine chromaffin cells, which developed neurite-like processes, and PC12 cells, which showed neuronal differentiation upon NGF treatment. In a few cases, primary neurons of the rat dorsal root ganglion were also examined. Brief pulse stimulation of the terminals and varicosities induced exocytosis accompanied by rapid formation of filopodia. These filopodia, 0.1–0.2 micron in diameter and up to 10 microns in length, formed within a few hundreds of milliseconds and then retracted within tens of seconds. They could also be induced by K depolarization. This rapid filopodial sprouting strongly depended on the presence of extracellular Ca2+ and could be abolished in a medium containing a Ca chelator (EGTA) or La2+. Anti-cytoskeletal agents colchicine and cytochalasin B failed to block this response completely but lidocaine fully suppressed it. Quantitative analysis of exocytosis and filopodial sprouting showed that they were independent events, not directly linked to each other, having different thresholds usually higher for filopodial formation. In PC12 cells, the extent of filopodial sprouting varied with the state of differentiation of the cells, suggesting a functional role of rapid sprouting during a particular phase of their differentiation. Filopodia could be induced with greater ease by repetitive stimulation. The same responses may occur at growth cones approaching the target cells or even at mature synapses particularly after repetitive electrical activity, possibly playing a role in use-dependent synapse formation or plasticity.

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Intracellular calcium release at fertilization in the sea urchin egg

Cited by 503 publications

References 20 publications

Regulation of Actin Binding and Actin Bundling Activities of Fascin by Caldesmon Coupled with Tropomyosin

Regulation of Actin Binding and Actin Bundling Activities of Fascin by Caldesmon Coupled with Tropomyosin

Nanomolar arachidonic acid influences the respiratory burst in eosinophils and neutrophils induced by GTP‐binding protein

Rapid sprouting of filopodia in nerve terminals of chromaffin cells, PC12 cells, and dorsal root neurons induced by electrical stimulation

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