Intracellular calcium regulation in sperm capacitation and acrosomal reaction
Intracellular calcium regulation in sperm capacitation and acrosomal reaction
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DOI：
10.1016/s0303-7207(01)00704-3
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发表时间：
2002-02-22
影响因子：
4.1
通讯作者：
Breitbart, H
中科院分区：
文献类型：
--
作者：
Breitbart, H
与卵子的透明带结合会刺激精子发生顶体反应，这是一个使精子能够穿透卵子的过程。在这种结合之前，精子在女性生殖道中经历了一系列的生化转换。统称为获能。获能的第一个事件是细胞内钙和碳酸氢盐的升高，以激活腺苷环化酶(AC)产生环-AMP，从而激活蛋白激酶A(PKA)以磷化某些蛋白质。在获能过程中，肌动蛋白聚合和膜结合磷脂酶C(PLC)也增加。精子与透明带结合可进一步激活cAMP/PKA和蛋白激酶C(PKC)。PKC在质膜上打开一条钙通道。PKA和肌醇-三磷酸一起激活顶体外膜的钙通道，导致细胞内钙的增加。顶体中钙的耗竭将激活质膜上一种储存操作的钙进入机制，导致细胞内钙的较高增加。导致膜融合和顶体反应。(C)2002爱思唯尔科学爱尔兰有限公司。保留所有权利。
Binding to the egg's zona pellucida stimulates the spermatozoon to undergo acrosome reaction, a process which enables the sperm to penetrate the egg. Prior to this binding, the spermatozoa undergo in the female reproductive tract a series of biochemical transformations. collectively called capacitation. The first event in capacitation is the elevation of intracellular calcium and bicarbonate to activate adenylyl cyclase (AC) to produce cyclic-AMP, which activates protein kinase A (PKA) to phosphor late certain proteins. During capacitation, there is also an increase in actin polymerization and in the membrane-bound phospholipase C (PLC). Sperm binding to zona-pellucida causes further activation of cAMP/PKA and protein kinase C (PKC), respectively. PKC opens a calcium channel in the plasma membrane. PKA together with inositol-trisphosphate activate calcium channels in the outer acrosomal membrane, which leads to an increase in cytosolic calcium. The depletion of calcium in the acrosome will activate a store-operated calcium entry mechanism in the plasma membrane, leading to a higher increase in cytosolic calcium. resulting in membrane fusion and acrosome reaction. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.