scholarly journals The Calcium Transient in Sea Urchin Eggs during Fertilization Requires the Production of Inositol 1,4,5-Trisphosphate

1998 ◽  
Vol 193 (2) ◽  
pp. 195-208 ◽  
Author(s):  
Shyh-Jye Lee ◽  
Sheldon S. Shen
Keyword(s):  
Sea Urchin ◽  
Calcium Transient ◽  
Sea Urchin Eggs ◽  
Inositol 1,4,5 Trisphosphate

Inositol-1,4,5-trisphosphate injection mimics fertilization potentials in sea urchin eggs

1986 ◽  
Vol 250 (2) ◽  
pp. C340-C344 ◽  
Author(s):  
B. E. Slack ◽  
J. E. Bell ◽  
D. J. Benos
Keyword(s):  
Membrane Potential ◽  
Partial Response ◽  
Sea Urchin ◽  
Time Course ◽  
Strongylocentrotus Purpuratus ◽  
Sea Urchin Eggs ◽  
Low Calcium ◽  
Inositol 1,4,5 Trisphosphate

The effects of inositol-1,4,5-trisphosphate (IP3) and of diacylglycerol (DAG) and its analogues on the membrane potential of eggs from the sea urchin Strongylocentrotus purpuratus were examined. Injection of IP3 into eggs resulted in a change in membrane potential that was similar in magnitude and time course to the fertilization potential elicited by sperm attachment. In low-calcium seawater, IP3 injection elicited a partial response. DAG and its analogues phorbol myristyl acetate and 1-oleoyl-2-acetylglycerol did not affect membrane potential either when applied by perfusion or when injected. The results indicate that IP3, but not DAG or its analogues, may be involved in the generation of the fertilization potential triggered by the interaction of sperm with sea urchin eggs.

scholarly journals Ca2+ release triggered by nicotinate adenine dinucleotide phosphate in intact sea urchin eggs

1995 ◽  
Vol 312 (3) ◽  
pp. 955-959 ◽  
Author(s):  
C M Perez-Terzic ◽  
E N Chini ◽  
S S Shen ◽  
T P Dousa ◽  
D E Clapham
Keyword(s):  
Sea Urchin ◽  
Specific Inhibitor ◽  
Intact Cells ◽  
Sea Urchin Eggs ◽  
Sea Urchin Egg ◽  
Cyclic Adp Ribose ◽  
Inositol 1,4,5 Trisphosphate ◽  
Dose Dependent Increase ◽  
Dose Dependent

Nicotinate adenine dinucleotide phosphate (NAADP) was recently identified [Lee and Aarhus (1995) J. Biol. Chem. 270, 2152-2157; Chini, Beers and Dousa (1995) J. Biol. Chem. 270, 3116-3223] as a potent Ca(2+)-releasing agent in sea urchin egg homogenates. NAADP triggered Ca2+ release by a mechanism that was distinct from inositol 1,4,5-trisphosphate (InsP3)- and cyclic ADP-ribose (cADPR)-induced Ca2+ release. When NAADP was microinjected into intact sea urchin eggs it induced a dose-dependent increase in cytoplasmic free Ca2+ which was independent of the extracellular [Ca2+]. The Ca2+ waves elicited by microinjections of NAADP originated at the site of injection and swept across the cytosol. As previously found in sea urchin egg homogenates, NAADP-induced Ca2+ release in intact eggs was not blocked by heparin or by prior desensitization to InsP3 or cADPR. Thio-NADP, a specific inhibitor of the NAADP-induced Ca2+ release in sea urchin homogenates [Chini, Beers and Dousa (1995) J. Biol. Chem. 270, 3116-3223] blocked NAADP (but not InsP3 or cADPR) injection-induced Ca2+ release in intact sea urchin eggs. Finally, fertilization of sea urchin eggs abrogated subsequent NAADP-induced Ca2+ release, suggesting that the NAADP-sensitive Ca2+ pool may participate in the fertilization response. This study demonstrates that NAADP acts as a selective Ca(2+)-releasing agonist in intact cells.

Increase of cGMP, cADP-ribose and inositol 1,4,5-trisphosphate preceding Ca2+ transients in fertilization of sea urchin eggs

Development ◽  
2001 ◽  
Vol 128 (22) ◽  
pp. 4405-4414 ◽  
Author(s):  
Ritsu Kuroda ◽  
Kenji Kontani ◽  
Yasunari Kanda ◽  
Toshiaki Katada ◽  
Takashi Nakano ◽  
...  
Keyword(s):  
Ryanodine Receptor ◽  
Sea Urchin ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Sea Urchin Eggs ◽  
Direct Measurements ◽  
Cyclic Adp Ribose ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor ◽  
Receptor Channel

Transient increases, or oscillations, of cytoplasmic free Ca2+ concentration, [Ca2+]i, occur during fertilization of animal egg cells. In sea urchin eggs, the increased Ca2+ is derived from intracellular stores, but the principal signaling and release system involved has not yet been agreed upon. Possible candidates are the inositol 1,4,5-trisphosphate receptor/channel (IP3R) and the ryanodine receptor/channel (RyR) which is activated by cGMP or cyclic ADP-ribose (cADPR). Thus, it seemed that direct measurements of the likely second messenger candidates during sea urchin fertilization would be essential to an understanding of the Ca2+ signaling pathway. We therefore measured the cGMP, cADPR and inositol 1,4,5-trisphosphate (IP3) contents of sea urchin eggs during the early stages of fertilization and compared these with the [Ca2+]i rise in the presence or absence of an inhibitor against soluble guanylate cyclase. We obtained three major experimental results: (1) cytosolic cGMP levels began to rise first, followed by cADPR and IP3 levels, all almost doubling before the explosive increase of [Ca2+]i; (2) most of the rise in IP3 occurred after the Ca2+ peak; IP3 production could also be induced by the artificial elevation of [Ca2+]i, suggesting the large increase in IP3 is a consequence, rather than a cause, of the Ca2+ transient; (3) the measured increase in cGMP was produced by the soluble guanylate cyclase of eggs, and inhibition of soluble guanylate cyclase of eggs diminished the production of both cADPR and IP3 and the [Ca2+]i increase without the delay of Ca2+ transients. Taken together, these results suggest that the RyR pathway involving cGMP and cADPR is not solely responsible for the initiating event, but contributes to the Ca2+ transients by stimulating IP3 production during fertilization of sea urchin eggs.

scholarly journals Thimerosal reveals calcium-induced calcium release in unfertilised sea urchin eggs

Zygote ◽  
1993 ◽  
Vol 1 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Alex McDougall ◽  
Isabelle Gillot ◽  
Michael Whitaker
Keyword(s):  
Sea Urchin ◽  
Calcium Release ◽  
Calcium Influx ◽  
Calcium Transient ◽  
Cell Types ◽  
Egg Activation ◽  
Free Calcium ◽  
Slow Increase ◽  
Sea Urchin Eggs ◽  
Calcium Induced Calcium Release

SummaryThe fertilisation calcium wave in sea urchin eggs triggers the onset of development. The wave is an explosive increase in intracellular free calcium concentration that begins at the point of sperm entry and crosses the egg in about 20 s. Thimerosal is a sulphydryl reagent that sensitises calcium release from intracellular stores in a variety of cell types. Treatment of unfertilised eggs with thimerosal causes a slow increase that results eventually in a large, spontaneous calcium transient and egg activation. At shorter times after thimerosal treatment, egg activation and the calcium transient can be triggered by calcium influx through voltage-gated calcium channels, a form of calcium-induced/calcium release (CICR). Thimerosal treatment also reduces the latency of the fertilisation calcium response and increases the velocity of the fertilisation wave. These results indicate that thimerosal can unmask CICR in sea urchin eggs and suggest that the ryanodine receptor channel based CICR may contribute to explosive calcium release during the fertilisation wave.

scholarly journals Regulation of cortical vesicle exocytosis in sea urchin eggs by inositol 1,4,5-trisphosphate and GTP-binding protein.

1986 ◽  
Vol 102 (1) ◽  
pp. 70-76 ◽  
Author(s):  
P R Turner ◽  
L A Jaffe ◽  
A Fein
Keyword(s):  
Sea Urchin ◽  
Intracellular Free Calcium ◽  
Free Calcium ◽  
Lytechinus Variegatus ◽  
Nucleotide Analogs ◽  
Sea Urchin Eggs ◽  
Sequence Of Events ◽  
Inositol 1,4,5 Trisphosphate ◽  
Vesicle Exocytosis ◽  
Nucleotide Binding Proteins

To investigate the roles of inositol 1,4,5-trisphosphate (InsP3) and guanyl nucleotide binding proteins (G-proteins) in the transduction mechanism coupling fertilization and exocytosis of cortical vesicles in sea urchin eggs, we microinjected InsP3 and guanyl nucleotide analogs into eggs of Lytechinus variegatus. Injection of 28 nM InsP3 caused exocytosis. However, if the egg was first injected with EGTA ([Cai] less than or equal to 0.1 microM; EGTA = 1.6 mM), InsP3 injection did not cause exocytosis, supporting the hypothesis that InsP3 acts by causing a rise in intracellular free calcium. Injection of 28 microM guanosine-5'-0-(3-thiotriphosphate) (GTP-gamma-S), a hydrolysis-resistant analog of GTP, caused exocytosis, but exocytosis did not occur if the egg was pre-injected with EGTA. Injection of 3 mM guanosine-5'-0-(2-thiodiphosphate) (GDP-beta-S), a metabolically stable analog of GDP, prevented sperm from stimulating exocytosis. However, injection of GDP-beta-S did not prevent the stimulation of exocytosis by InsP3. These results suggested the following sequence of events. The sperm activates a G-protein, which stimulates production of InsP3. InsP3 elevates intracellular free calcium, which causes exocytosis.

Inositol 1,4,5-trisphosphate microinjection activates sea urchin eggs

Nature ◽  
1984 ◽  
Vol 312 (5995) ◽  
pp. 636-639 ◽  
Author(s):  
Michael Whitaker ◽  
R. F. Irvine
Keyword(s):  
Sea Urchin ◽  
Sea Urchin Eggs ◽  
Inositol 1,4,5 Trisphosphate

Cyclic ADP-ribose activates caffeine-sensitive calcium channels from sea urchin egg microsomes

1998 ◽  
Vol 274 (2) ◽  
pp. C430-C439 ◽  
Author(s):  
Claudio F. Pérez ◽  
Juan José Marengo ◽  
Ricardo Bull ◽  
Cecilia Hidalgo
Keyword(s):  
Sea Urchin ◽  
Microsomal Fraction ◽  
Ruthenium Red ◽  
Single Channels ◽  
Channel Activity ◽  
Sea Urchin Eggs ◽  
Sea Urchin Egg ◽  
Cyclic Adp Ribose ◽  
Inositol 1,4,5 Trisphosphate ◽  
Intracellular Ca

Adenosine 5′-cyclic diphosphoribose [cyclic ADP-ribose (cADPR)], a metabolite of NAD+ that promotes Ca2+ release from sea urchin egg homogenates and microsomal fractions, has been proposed to act as an endogenous agonist of Ca2+ release in sea urchin eggs. We describe experiments showing that a microsomal fraction isolated from Tetrapigus nyger sea urchin eggs displayed Ca2+-selective single channels with conductances of 155.0 ± 8.0 pS in asymmetric Cs+ solutions and 47.5 ± 1.1 pS in asymmetric Ca2+ solutions. These channels were sensitive to stimulation by Ca2+, ATP, and caffeine, but not inositol 1,4,5-trisphosphate, and were inhibited by ruthenium red. The channels were also activated by cADP-ribose in a Ca2+-dependent fashion. Calmodulin and Mg2+, but not heparin, modulated channel activity in the presence of cADP-ribose. We propose that these Ca2+ channels constitute the intracellular Ca2+-induced Ca2+ release pathway that is activated by cADP-ribose in sea urchin eggs.

Role of guanylyl cyclase in fertilisation of sea urchin eggs

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S18-S19
Author(s):  
Ritsu Kuroda ◽  
Kenji Kontani ◽  
Yasunari Kanda ◽  
Toshiaki Katada ◽  
Yu-ichi Satoh ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Guanylyl Cyclase ◽  
Sh2 Domain ◽  
Signalling Pathway ◽  
Transient Increase ◽  
Egg Activation ◽  
Sea Urchin Eggs ◽  
Intracellular Injection ◽  
Inositol 1,4,5 Trisphosphate ◽  
Receptor Channel

A transient increase in cytosolic free calcium ion concentration ([Ca2+]i) (Ca2+-transient) takes place in the early stages of fertilisation of sea urchin eggs as well as in other animal eggs (Miyazaki et al., 1993). This transient increase in [Ca2+]i propagates across the egg as a Ca2+ wave, which is thought to be a necessary and sufficient event for egg activation (Whitaker & Swarm, 1993). In sea urchin eggs, the rise in [Ca2+], is caused by release of Ca2+ from the endoplasmic reticulum (ER) via one or both of two pathways: (a) inositol 1,4,5-trisphosphate (IP3) and the inositol 1,4,5-trisphosphate receptor/channel (IP3R) or (b) cADP-ribose (cADPR) and/or cGMP and the ryanodine receptor/channel (RyR) (Berridge, 1993). The signalling pathways from sperm to ER of eggs are not yet fully explained. Recent evidence from two lines of experiments has excited more controversy. First, intracellular injection of SH2 domain of phospholipase Cγ, which produced IP3, completely inhibited the increase in [Ca2+]i (Carroll et al., 1999). Another series of experiments showed that nitric oxide (NO) gas was produced in sperm during their acrosome reaction and in eggs during fertilisation, and that the intracellular injection of NO synthase caused egg activation (Epel, this supplement). NO gas is expected to stimulate the production of cGMP by activating soluble guanylyl cyclase (Garthewaite, 1991). Thus, it seems that direct measurements of the second messenger candidates during sea urchin fertilisation are essential to an understanding of the calcium signalling pathway. We previously measured the IP3, cGMP and cADPR contents of sea urchin eggs, and compared the time courses of their changes with that of the [Ca2+]i change (Kuroda et al., 1997). We now examine further the involvement of guanylyl cyclase in the Ca2+ signalling pathway at fertilisation of sea urchin eggs.

scholarly journals Analysis of the Calcium Transient at NEB During the First Cell Cycle in Dividing Sea Urchin Eggs

1996 ◽  
Vol 191 (1) ◽  
pp. 5-16 ◽  
Author(s):  
C. L. Browne ◽  
R. Creton ◽  
E. Karplus ◽  
P. J. Mohler ◽  
R. E. Palazzo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Sea Urchin ◽  
Calcium Transient ◽  
Sea Urchin Eggs
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