ISSN:
0148-7280
Keywords:
sulfhydryl gropus
;
sea urchin eggs
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Unfertilized sea urchin eggs exposed to the sulfhydryl reagents Ag+ or N-ethylmaleimide either elevated fertilizationlike membranes, formed surface protrusions, developed a clear cortical layer devoid of organelles, or cytolysed. The relative fraction of each modification varied from batch to batch and was also dose and time dependent. With Ag+ and higher doses of N-EMI (10-3 M), the most common effect was the elevation of a membrane indicating cortical exocytosis, while at lower doses of N-EMI protrusions were predominant. Glutathione (GSH) protected eggs against these reagents also in a dose-dependent manner. Eggs exposed to equimolar amounts of N-EMI and GSH, which otherwise formed membranes, produced protrusions, while increasing GSH tenfold afforded complete protection. We suggest there are two targets for the sulfhydryl reagents-the first, SH groups on proteins that regulate the release of Ca2+ from the intracellular sequestering mechanism which subsequently triggers cortical exocytosis; the second, SH groups on the egg surface that may regulate cortical organization.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1120190206
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