Guanylyl cyclase and cGMP-specific phosphodiesterase participate in the acrosome reaction of starfish sperm
Guanylyl cyclase and cGMP-specific phosphodiesterase participate in the acrosome reaction of starfish sperm
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DOI：
10.1017/s0967199404002977
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发表时间：
2004-11-01
期刊：
影响因子：
1.7
通讯作者：
Matsumoto, M
中科院分区：
文献类型：
--
作者：
Kawase, O;Ueno, S;Matsumoto, M
在海星（Asterias amurensis）中，顶体反应诱导物质（acrosome reaction-inducing substance，ARTS）、Co-ARIS和astrosap三种成分的协同作用是引起顶体反应的主要原因。在实验上，ARTS和asterosap足以诱导。然而，当精子仅用asterosap处理时，它们对卵冻没有反应。在这项研究中，我们分析了顶体反应的机制，使用精子失活的asterosap为线索。Asterosap通过激活Asterosap受体（一种鸟苷酸环化酶）引起细胞内cGMP快速和短暂增加，并引起细胞内Ca 2+增加。当精子用asterosap预处理时，鸟苷酸环化酶似乎通过去磷酸化而不可逆地失活。他们对阿里斯仍有反应，但对asterosap不再有反应。然而，在存在IBMX或扎匹司特（磷酸二酯酶（PDE）抑制剂）的情况下，它们保留了对单独的卵冻或阿里斯进行顶体反应的能力。IBMX和扎匹司特抑制cGMP的细胞内催化，但不是cAMP。这些结果表明，鸟苷酸环化酶和cGMP特异性，IBMX和扎匹司特敏感的PDE参与顶体反应的调节。
In the starfish, Asterias amurensis, the cooperation of three components of the egg jelly i.e. ARTS (acrosome reaction-inducing substance), Co-ARIS and asterosap, is responsible for inducing the acrosome reaction. Experimentally, ARTS 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.