Ca2+ uptake and IP3‐induced Ca2+ release in permeabilized human lymphocytes

Eberl, Gérard; Schnell, K. F.

doi:10.1016/0014-5793(87)80400-3

Cited by 6 publications

(2 citation statements)

References 18 publications

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“…Most previous studies of Ins(l,4,5)Pr-induced Ca 2+ release have utilized either cell-free systems or permeabilized cells. In general, these studies have shown that the intracellular Ca 2+ release is linearly proportional to the concentration of Ins(l,4,5)P3 for low doses and it plateaus for higher doses where most of the Ca 2+ pools were depleted by Ins(l,4,5)P3 (6,9,19,22,23,30,33,38,41,45,56,61). We have observed both linear and log-linear responses that do not appear to be correlated with the amount of Ins(1,4,5)P3 injected.…”

Section: Comlmrison To Previous Studies Of Ca ~" Releasementioning

confidence: 98%

Inositol 1,4,5-trisphosphate-induced calcium release in the organelle layers of the stratified, intact egg of Xenopus laevis.

Han

Nuccitelli

1990

The Journal of Cell Biology

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Abstract. Using double-barreled, Ca2÷-sensitive microelectrodes, we have examined the characteristics of the Ca 2+ release by inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) in the various layers of Xenopus laevis eggs in which the organelles had been stratified by centrifugation. Centrifugation of living eggs stratifies the organelles yet retains them in the normal cytoplasmic milieu. The local increase in intracellular free Ca 2+ in each layer was directly measured under physiological conditions using theta-tubing, doublebarreled, Ca2+-sensitive microelectrodes in which one barrel was filled with the Ca 2+ sensor and the other was filled with Ins(1,4,5)P3 for microinjection. The two tips of these electrodes were very close to each other (3/~m apart) enabling us to measure the kinetics of both the highly localized intracellular Ca 2÷ release and its subsequent removal in response to Ins(1,4,5)P3 injection. Upon Ins(1,4,5)P3 injection, the ER-enriched layer exhibited the largest release of Ca 2+ in a dosagedependent manner, whereas the other layers, mitochondria, lipid, and yolk, released 10-fold less Ca 2÷ in a dosage-independent manner. The removal of released Ca 2÷ took place within ,x,1 min. The sensitivity to Ins(1,4,5)P3 and the time course of intracellular Ca ~+ release in the unstratified (unactivated) egg is nearly identical to that observed in the ER layer of the stratified egg. Our data suggest that the ER is the major organelle of the Ins(1,4,5)Prsensitive Ca 2÷ store in the egg of Xenopus laevis. transient increase in intracellular free calcium concentration ([Ca2+]~) during sperm-egg interaction is one of the main ionic events of fertilization that triggers the initiation of development of the zygote (13, 21,46,60). This increase in [Ca2+]i has been observed during the activation of a wide variety of eggs using at least three different techniques for Ca ~+ measurement. The photoprotein, aequorin, was the first Ca 2+ indicator to reveal a wave of increased free [Ca2+]i after activation of the eggs of the medaka fish (16,20,39,62), sea urchin (12, 48), starfish (10), frog (25), mouse (7,8), and hamster (29). Pairs of Ca ~+ electrodes were used to study the wave in frog eggs (3,4,35) and the fluorescent Ca 2+ probe, fura-2, has been used in sea urchins (17,51,59).Recent studies of sea urchin and frog eggs have indicated that sperm-egg interaction may release Ca 2+ through the inositol lipid cascade. Sperm binding to its receptor at the egg surface activates a phosphoinositide-specific phospholipase C enzyme (24,54,55). The phospholipase C enzyme hydrolyzes phosphoinositol 4,5-bisphosphate (PIP2) t producing two second messengers, inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) and diacylglycerol. Ins(1,4,5)P3 releases Ca 2+ from intracellular Ca 2÷ stores whereas diacylglycerol activates the phospholipid-and Ca:÷-dependent protein kinase, protein kinase C, which is involved in many cellular re-1. Abbreviaa'ons used in this paper: CG, cortical granules; Ins(l,4,5)P3, inositol 1,4,5-trisphosphate; pCa, negative...

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Section: Comlmrison To Previous Studies Of Ca ~" Releasementioning

confidence: 98%

Inositol 1,4,5-trisphosphate-induced calcium release in the organelle layers of the stratified, intact egg of Xenopus laevis.

Han

Nuccitelli

1990

The Journal of Cell Biology

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“…EGTA (3 mM) was used in some experiments to lower extracellular [Ca 2ϩ ] i to 150 nM. IP 3 -mediated Ca 2ϩ release in T cells was carried out after permeabilizing the cells with saponin (150 µg/ml), as described earlier (15) [Ca 2ϩ ] i in T cells were calculated over the period of 300 s starting from the time of concanavalin A (Con A) stimulation. In the present study, we determined the effects of various Con A concentrations on T cell [Ca 2ϩ ] i elevation and found T cell stimulation to be maximal at the 100-µg/ml concentration.…”

Section: Methodsmentioning

confidence: 99%

PGE₂suppresses mitogen-induced Ca²⁺mobilization in T cells

Choudhry

Hockberger

Sayeed

1999

American Journal of Physiology-Regulatory, Integrative and Comp

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PGE2-mediated suppression of T cell proliferation during sepsis could result from altered Ca2+ signaling. The present study evaluated the effects of PGE2 on Ca2+ release from intracellular stores and its influx through the plasma membrane in splenic T cells from Sprague-Dawley rats. Intracellular Ca2+ concentration ([Ca2+]i) responses in individual T cells were assessed using the Ca2+ imaging technique, and the release of Ca2+ from intracellular stores and Ca2+ influx were spectrofluorometrically quantified in T cell suspensions. Under unstimulated conditions, nearly 85% of T cells exhibited [Ca2+]i

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Guanine nucleotide‐induced Ca²⁺ release in permeabilized murine thymocytes

1988

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GTP and IP3 induced Ca2+ release from an internal store in permeabilized murine thymocytes loaded with Ca2+ by ATP. Ca2+ release was dependent on the concentration of GTP: half‐maximal release with 0.5 μM and maximal release with 10 μM. The GTP effect was completely abolished by 100 μM GTPγS, GMPPNP and UTP. None of the other nucleotides used except ITP induced Ca2+ release. When GTP was added after the effect of IP3 had virtually subsided, and vice versa, further Ca2+ release occurred, which led to the conclusion that the mechanism of GTP‐mediated Ca2+ release may be different from that of IP3‐mediated release.

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Ca²⁺ uptake and IP₃‐induced Ca²⁺ release in permeabilized human lymphocytes

Cited by 6 publications

References 18 publications

Inositol 1,4,5-trisphosphate-induced calcium release in the organelle layers of the stratified, intact egg of Xenopus laevis.

Inositol 1,4,5-trisphosphate-induced calcium release in the organelle layers of the stratified, intact egg of Xenopus laevis.

PGE₂suppresses mitogen-induced Ca²⁺mobilization in T cells

Guanine nucleotide‐induced Ca²⁺ release in permeabilized murine thymocytes

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Ca2+ uptake and IP3‐induced Ca2+ release in permeabilized human lymphocytes

Cited by 6 publications

References 18 publications

Inositol 1,4,5-trisphosphate-induced calcium release in the organelle layers of the stratified, intact egg of Xenopus laevis.

Inositol 1,4,5-trisphosphate-induced calcium release in the organelle layers of the stratified, intact egg of Xenopus laevis.

PGE2suppresses mitogen-induced Ca2+mobilization in T cells

Guanine nucleotide‐induced Ca2+ release in permeabilized murine thymocytes

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Product

Resources

About

Ca²⁺ uptake and IP₃‐induced Ca²⁺ release in permeabilized human lymphocytes

PGE₂suppresses mitogen-induced Ca²⁺mobilization in T cells

Guanine nucleotide‐induced Ca²⁺ release in permeabilized murine thymocytes