scholarly journals DIRECT ISOLATION OF THE HYALINE LAYER PROTEIN RELEASED FROM THE CORTICAL GRANULES OF THE SEA URCHIN EGG AT FERTILIZATION

1970 ◽  
Vol 45 (3) ◽  
pp. 615-622 ◽  
Author(s):  
R. E. Kane
Keyword(s):  
Protein Content ◽  
Sea Urchin ◽  
Insoluble Fraction ◽  
Glycerol Solution ◽  
Cortical Granules ◽  
Simple Method ◽  
Quantitative Measurements ◽  
Hawaiian Species ◽  
Sea Urchin Egg

Treatment of the eggs of the sea urchin with a 1 M solution of glycerol at fertilization allows the recovery from this solution of the protein released from the cortical granules, including that which would normally give rise to the hyaline layer. The calcium-gelable protein previously extracted from whole eggs and from isolated cortical material was found to be present in the glycerol solution, confirming its localization in the cortical granules and its role in the hyaline layer. Quantitative measurements on the eggs of two Hawaiian species, Colobocentrotus atratus and Pseudoboletia indiana, which have the widest variation in the gel protein content, demonstrated that a proportionate amount of this material was released at fertilization in these species, which correlates with the thickness of the hyaline layer in the two cases. In addition, the calcium-insoluble fraction of Sakai can be extracted from these eggs after removal of the hyaline protein by glycerol, showing that this is a different material. A simple method for the separation of the hyaline protein from the calcium-insoluble fraction in solution is provided.

scholarly journals Poisson-distributed active fusion complexes underlie the control of the rate and extent of exocytosis by calcium.

1996 ◽  
Vol 134 (2) ◽  
pp. 329-338 ◽  
Author(s):  
S S Vogel ◽  
P S Blank ◽  
J Zimmerberg
Keyword(s):  
Poisson Process ◽  
Sea Urchin ◽  
Physiological Responses ◽  
Cortical Granule ◽  
Cortical Granules ◽  
Granule Exocytosis ◽  
Calcium Dependence ◽  
Sea Urchin Egg ◽  
High Calcium ◽  
Cortical Granule Exocytosis

We have investigated the consequences of having multiple fusion complexes on exocytotic granules, and have identified a new principle for interpreting the calcium dependence of calcium-triggered exocytosis. Strikingly different physiological responses to calcium are expected when active fusion complexes are distributed between granules in a deterministic or probabilistic manner. We have modeled these differences, and compared them with the calcium dependence of sea urchin egg cortical granule exocytosis. From the calcium dependence of cortical granule exocytosis, and from the exposure time and concentration dependence of N-ethylmaleimide inhibition, we determined that cortical granules do have spare active fusion complexes that are randomly distributed as a Poisson process among the population of granules. At high calcium concentrations, docking sites have on average nine active fusion complexes.

Purification of cortical granules from unfertilized sea urchin egg homogenates by zonal centrifugation

1972 ◽  
Vol 29 (3) ◽  
pp. 307-320 ◽  
Author(s):  
H. Schuel ◽  
W.L. Wilson ◽  
R.S. Bressler ◽  
J.W. Kelly ◽  
J.R. Wilson
Keyword(s):  
Sea Urchin ◽  
Cortical Granules ◽  
Sea Urchin Egg

scholarly journals A COMPARATIVE STUDY OF THE ISOLATION OF THE CORTEX AND THE ROLE OF THE CALCIUM-INSOLUBLE PROTEIN IN SEVERAL SPECIES OF SEA URCHIN EGG

1969 ◽  
Vol 41 (1) ◽  
pp. 133-144 ◽  
Author(s):  
R. E. Kane ◽  
R. E. Stephens
Keyword(s):  
Comparative Study ◽  
Sea Urchin ◽  
Protein Composition ◽  
Cortical Region ◽  
Cortical Granules ◽  
Divalent Ions ◽  
Sea Urchin Egg ◽  
Protein Gelation ◽  
Isolated Cortex

A comparative study was made of the isolation of the cortex in the eggs of several sea urchin species. Since the isolation method developed by Sakai depends on the presence of magnesium in the medium, the protein composition of the cortex was investigated to determine whether the protein component of the egg described by Kane and Hersh which is gelled by divalent ions, is present in these cortices. Isolation of the cortex was found to require the same divalent ions at the same concentrations as protein gelation, and in the eggs of some species much of the gel protein of the cell was found in the isolated cortical material. In the eggs of other species a smaller fraction of this protein was found in the isolated cortex, although it was more concentrated there than in the endoplasm, and in one species this protein appeared to be uniformly distributed throughout the cell. These results indicate that this protein is localized in the cortical region of the eggs of some species of sea urchin, possibly in the cortical granules, but also point up the fact that results from one species cannot be uncritically extrapolated to others.

scholarly journals THE MEMBRANE CAPACITANCE OF THE SEA URCHIN EGG

1957 ◽  
Vol 3 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Lord Rothschild
Keyword(s):  
Plasma Membrane ◽  
Sea Urchin ◽  
Sea Water ◽  
Unit Area ◽  
Membrane Capacitance ◽  
Percentage Reduction ◽  
Cortical Granules ◽  
Sea Urchin Egg

1. The surface of the unfertilized sea urchin egg is folded and the folds are reversibly eliminated by exposing the egg to hypotonic sea water. If the plasma membrane is outside the layer of cortical granules, unfolding may explain why the membrane capacitance per unit area decreases (and does not increase) when a sea urchin egg is put into hypotonic sea water. 2. The degree of surface folding markedly increases after fertilization, which provides an explanation for the increase in membrane capacitance per unit area observed after fertilization. 3. The percentage reduction in membrane folding in fertilized eggs after immersion in hypotonic sea water is probably sufficient to explain the decrease in membrane capacitance per unit area observed in these conditions.

Immunocytochemical evidence suggesting heterogeneity in the population of sea urchin egg cortical granules

1988 ◽  
Vol 125 (1) ◽  
pp. 1-7 ◽  
Author(s):  
John A. Anstrom ◽  
Jia E. Chin ◽  
David S. Leaf ◽  
Annette L. Parks ◽  
Rudolf A. Raff
Keyword(s):  
Sea Urchin ◽  
Cortical Granules ◽  
Sea Urchin Egg

Fertilisation in fish: a cortical alveolar lectin and its potential role in the block to polyspermy

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S66-S66 ◽  
Author(s):  
Shigeki Yasumasu ◽  
Nathan J. Wardrip ◽  
Bruce D. Zenner ◽  
Young M. Lee ◽  
Alan J. Smith ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Column Chromatography ◽  
Cortical Granule ◽  
Affinity Column ◽  
Cortical Granules ◽  
Amino Terminal ◽  
Sea Urchin Egg ◽  
Affinity Column Chromatography ◽  
Sperm Penetration ◽  
Carboxyl Terminal

An animal egg such as amphibian, mammalian or sea urchin egg receives only a single sperm at fertilisation. After binding of the first sperm, the egg is prevented from allowing the entry of additional sperm. In fact, polyspermy results in aborted development of the zygote. It has been generally accepted that a molecule(s) released from cortical granules participates in the block to polyspermy. As one such molecule, a cortical granule lectin has been isolated from unfertilised Xenopus eggs (Xenopus cortical granule lectin; XCGL). XCGL is released into the perivitelline space after fertilisation, and forms a complex with J1 jelly molecules to form an F layer, resulting in a block to additional sperm penetration.A lectin molecule has also been purified from the eggs of several species of fish. The fish egg lectin is located in the cortical alveoli and is released from them after fertilisation. However, its biological function is unclear. We isolated cortical alveolar lectin from unfertilised eggs of Chinook salmon through affinity column chromatography (salmon egg lectin; SEL). The lectin activity was estimated by haemagglutination. The activity of the purified SEL was most strongly inhibited by L-rhamnose and D-galactose, but not by EDTA. Further analysis by C4 reverse-phase column chromatography using HPLC revealed that the lectin was composed of three subunit proteins: 24K, 26Ka and 26Kb proteins. In addition, we cloned cDNAs for them by RT-PCR. The deduced amino acid sequence of the 26Ka protein was homologous with that of the 26Kb protein (identity, 96.4%). Identities of the 24K with the 26Ka and the 26Kb proteins were 55.9% and 66.7%, respectively. A database search revealed that a lectin molecule similar to the SEL had been identified in Anthocidaris crassispina egg (sea urchin egg lectin; SUEL). The SUEL is composed of 105 amino acids, and is similar to both amino-terminal and carboxyl-terminal halves of the SELs. Thus, the SEL molecule is composed of two repeats of such SUEL-like domains, suggesting that the SEL gene was produced by gene duplication.

The GTP-binding protein RhoA localizes to the cortical granules of Strongylocentrotus purpuratus sea urchin egg and is secreted during fertilization

2000 ◽  
Vol 79 (2) ◽  
pp. 81-91 ◽  
Author(s):  
Patricia Cuéllar-Mata ◽  
Guadalupe Martínez-Cadena ◽  
Juana López-Godínez ◽  
Armando Obregón ◽  
Jesús García-Soto
Keyword(s):  
Sea Urchin ◽  
Binding Protein ◽  
Strongylocentrotus Purpuratus ◽  
Cortical Granules ◽  
Gtp Binding Protein ◽  
Gtp Binding ◽  
Sea Urchin Egg

scholarly journals Metabolic similarities between fertilization and phagocytosis. Conservation of a peroxidatic mechanism.

1979 ◽  
Vol 149 (4) ◽  
pp. 938-953 ◽  
Author(s):  
S J Klebanoff ◽  
C A Foerder ◽  
E M Eddy ◽  
B M Shapiro
Keyword(s):  
Sea Urchin ◽  
Polymorphonuclear Leukocytes ◽  
Cortical Granules ◽  
Sea Urchin Eggs ◽  
Sea Urchin Egg ◽  
Hatching Process ◽  
Fertilization Membrane ◽  
Catalyzed Reactions ◽  
Kinetics Of ◽  
Estrogen Binding

At the time of fertilization, sea urchin eggs release a peroxidase which, together with H2O2 generated by a respiratory burst, is responsible for hardening of the fertilization membrane. We demonstrate here that the ovoperoxidase of unfertilized eggs is located in cortical granules and, after fertilization, is concentrated in the fertilization membrane. Fertilization of sea urchin eggs or their parthenogenetic activation with the ionophor A23187 also results in (a) the conversion of iodide to a trichloroacetic acid-precipitable form (iodination), (b) the deiodination of eggs exogenously labeled with myeloperoxidase and H2O2, (c) the degradation of thyroxine as measured by the recovery of the released radioiodine at the origin and in the inorganic iodide spot on paper chromatography, and (d) the conversion of estradiol to an alcohol-precipitable form (estrogen binding). The iodination reaction and the binding of estradio occurs predominantly in the fertilization membrane where the ovoperoxidase is concentrated. From the estimation of the kinetics of incorporation of iodine, we determine that the peroxidative system is active for 30 min after fertilization, long after hardening of the fertilization membrane is complete. Most of the bound iodine is lost during the hatching process. Iodination of albumin is catalyzed by the material released from the egg during fertilization, when combined with H2O2 and iodide. Iodination, thyroxine degradation, and estradiol binding are inhibited by azide, cyanide, aminotriazole, methimazole, ascorbic acid and ergothioneine, all of which can inhibit peroxidase-catalyzed reactions. These responses of the sea urchin egg to fertilization are strikingly similar to the changes induced in polymorphonuclear leukocytes by phagocytosis and, in both instances, a peroxidative mechanism may be involved.

Exocytosis reconstituted from the sea urchin egg is unaffected by calcium pretreatment of granules and plasma membrane

1988 ◽  
Vol 8 (4) ◽  
pp. 335-343 ◽  
Author(s):  
Tim Whalley ◽  
Michael Whitaker
Keyword(s):  
Plasma Membrane ◽  
Sea Urchin ◽  
Calcium Ions ◽  
Calcium Ion ◽  
Secretory Granules ◽  
Cortical Granules ◽  
Allosteric Activation ◽  
Ion Concentrations ◽  
Sea Urchin Egg ◽  
Reconstituted System

Micromolar calcium ion concentrations stimulate exocytosis in a reconstituted system made by recombining in the plasma membrane and cortical secretory granules of the sea urchin egg. The isolated cortical granules are unaffected by calcium concentrations up to 1 mM, nor do granule aggregates undergo any mutual fusion at this concentration. Both isolated plasma membrane and cortical granules can be pretreated with 1 mM Ca before reconstitution without affecting the subsequent exocytosis of the reconstituted system in response to micromolar calcium concentrations. On reconstitution, aggregated cortical granules will fuse with one another in response to micromolar calcium provided that one of their number is in contact with the plasma membrane. If exocytosis involves the generation of lipid fusogens, then these results suggest that the calcium-stimulated production of a fusogen can occur only when contiguity exists between cortical granules and plasma membrane. They also suggest that a substance involved in exocytosis can diffuse and cause piggy-back fusion of secretory granules that are in contact with the plasma membrane. Our results are also consistent with a scheme in which calcium ions cause a reversible, allosteric activation of an exocytotic protein.

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