Guanylyl cyclase and cGMP-specific phosphodiesterase participate in the acrosome reaction of starfish sperm

Osamu Kawase, Seiichi Ueno, Hiroyuki Minakata, Motonori Hoshi, Midori Matsumoto

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

In the starfish, Asterias amurensis, the cooperation of three components of the egg jelly, i.e. ARIS (acrosome reaction-inducing substance), Co-ARIS and asterosap, is responsible for inducing the acrosome reaction. Experimentally, ARIS and asterosap are sufficient for the induction. However, when sperm are treated only with asterosap, they become unresponsive to the egg jelly to undergo the reaction. In this study, we analysed the mechanism of the acrosome reaction, using sperm inactivation by asterosap as a clue. Asterosap causes a rapid and transient increase in intracellular cGMP through the activation of the asterosap receptor, a guanylyl cyclase, and causes an increase in intracellular Ca2+. When sperm were pretreated with asterosap, the guanylyl cyclase seemed to be inactivated irreversibly by dephosphorylation. They were still responsive to ARIS but no longer to asterosap. However, in the presence of IBMX or zaprinast, inhibitors against phosphodiesterases (PDEs), they retained their capacity to undergo the acrosome reaction in response to the egg jelly or ARIS alone. IBMX and zaprinast suppressed the intracellular catabolism of cGMP, but not of cAMP. These results suggest that guanylyl cyclase and cGMP-specific, IBMX- and zaprinast-susceptible PDEs are involved in the regulation of the acrosome reaction.

Original languageEnglish
Pages (from-to)345-355
Number of pages11
JournalZygote
Volume12
Issue number4
DOIs
Publication statusPublished - 2004 Nov 1

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Keywords

  • Acrosome reaction
  • Guanylyl cyclase
  • Phosphodiesterase
  • Starfish
  • cGMP

ASJC Scopus subject areas

  • Developmental Biology
  • Cell Biology

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