Abstract
Fertilization is accompanied by a transient increase in the concentration of intracellular Ca2+, which serves as a signal for initiating development. Some of the Ca2+ appears to be released from intracellular stores by the binding of inositol trisphosphate (IP3) to its receptor. However, in sea urchin eggs, other mechanisms appear to participate. Cyclic adenosine diphosphate-ribose (cADPR), a naturally occurring metabolite of nicotinamide adenine dinucleotide, is as potent as IP3 in mobilizing Ca2+ in sea urchin eggs. Experiments with antagonists of the cADPR and IP3 receptors revealed that both Ca2+ mobilizing systems were activated during fertilization. Blockage of either of the systems alone was not sufficient to prevent the sperm-induced Ca 2+ transient. This study provides direct evidence for a physiological role of cADPR in the Ca2+ signaling process.
Original language | English (US) |
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Pages (from-to) | 352-355 |
Number of pages | 4 |
Journal | Science |
Volume | 261 |
Issue number | 5119 |
DOIs | |
State | Published - 1993 |
Externally published | Yes |