Calpain modulates capacitation and acrosome reaction through cleavage of the spectrin cytoskeleton
Calpain modulates capacitation and acrosome reaction through cleavage of the spectrin cytoskeleton
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DOI：
10.1530/rep-09-0545
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发表时间：
2010-11-01
期刊：
影响因子：
3.8
通讯作者：
Hernandez-Gonzalez, Enrique O.
中科院分区：
文献类型：
--
作者：
Bastian, Yadira;Roa-Espitia, Ana L.;Hernandez-Gonzalez, Enrique O.
对哺乳动物受精的研究表明，钙离子在使精子穿透卵母细胞的生化和生理事件中起着重要的作用。Ca~(2+)是一种信号转导分子，特别是介导获能和顶体反应(AR)。在具有受精能力之前，精子必须经历几个分子、生化和生理变化，其中钙离子起着关键作用。Calain-1和Calain-2是哺乳动物精子中广泛研究的钙依赖的蛋白水解酶，参与获能和AR，但对其作用机制知之甚少。在这项工作中，我们在豚鼠精子中建立了calastatin和calain-1的联系，以及这种复合体在获能过程中所经历的变化。我们发现，在获能过程中，Calain-1被从细胞质重新定位并转移到质膜(PM)，在那里它可以切割PM相关细胞骨架的蛋白质之一，从而促进AR。上述结果依赖于钙调蛋白的磷酸化和细胞外钙离子的存在。我们的发现强调了精子细胞骨架在获能和AR调节中的作用。此外，我们的发现还揭示了钙蛋白酶和钙在精子中发挥作用的机制之一。生殖(2010)140 673-684
Research on fertilization in mammalian species has revealed that Ca2+ is an important player in biochemical and physiological events enabling the sperm to penetrate the oocyte. Ca2+ is a signal transducer that particularly mediates capacitation and acrosome reaction (AR). Before becoming fertilization competent, sperm must experience several molecular, biochemical, and physiological changes where Ca2+ plays a pivotal role. Calpain-1 and calpain-2 are Ca2+-dependent proteases widely studied in mammalian sperm; they have been involved in capacitation and AR but little is known about their mechanism. In this work, we establish the association of calpastatin with calpain-1 and the changes undergone by this complex during capacitation in guinea pig sperm. We found that calpain-1 is relocated and translocated from cytoplasm to plasma membrane (PM) during capacitation, where it could cleave spectrin, one of the proteins of the PM-associated cytoskeleton, and facilitates AR. The aforementioned results were dependent on the calpastatin phosphorylation and the presence of extracellular Ca2+. Our findings underline the contribution of the sperm cytoskeleton in the regulation of both capacitation and AR. In addition, our findings also reveal one of the mechanisms by which calpain and calcium exert its function in sperm. Reproduction (2010) 140 673-684