Send to

Choose Destination
See comment in PubMed Commons below
Biol Pharm Bull. 2007 Jul;30(7):1332-5.

Effects of proteasome inhibitors on fertilization of the sea urchin Anthocidaris crassispina.

Author information

Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Toba, Mie, Japan.


The sperm proteasome has been reported to be involved in sperm penetration through the proteinaceous egg-coat during fertilization in ascidians and mammals. However, such an extracellular role for the sperm proteasome in fertilization is not known in other deuterostomes. Here, we investigated the effects of two proteasome inhibitors on fertilization of the sea urchin Anthocidaris crassispina. Two proteasome inhibitors, MG-132 and MG-115, inhibited fertilization, whereas E-64-d, chymostatin or leupeptin showed no inhibition at 100 microM. MG-132 inhibited the egg-jelly-induced acrosome reaction, but not the reaction induced by the Ca(2+) ionophore ionomycin. MG-132 and MG-115, but not E-64-d, inhibited the fertilization of dejellied eggs by acrosome-reacted sperm. Furthermore, MG-132-susceptible proteasome activity was detected in the acrosomal contents. These results suggest that the sperm proteasome plays a key role not only in the acrosome reaction, in particular, in a process before the increase in intracellular Ca(2+) concentration but also in the sperm penetration through the vitelline coat, most probably as a lysin.

[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for J-STAGE, Japan Science and Technology Information Aggregator, Electronic
    Loading ...
    Support Center