酪氨酸磷酸化在精子获能过程中的作用

在精子细胞发生顶体反应并使卵母细胞受精之前，获能是一个重要的生理先决条件。获能是精子在雌性生殖道中进一步成熟的复杂现象，其赋予精子以增强活性的能力，使精子能够与卵母细胞透明带（ZP）相互作用，进行顶体反应并与卵母细胞质膜融合，进而完成受精过程。然而精子获能的分子机制十分复杂，目前还未完全明确，但获能后的精子会有诸多结构及生化方面的变化，如蛋白酪氨酸磷酸化、精子膜胆固醇外流、活性氧的产生及精子膜超极化。蛋白质通过磷酸化或去磷酸化调节精子获能和顶体反应等一些重要的现象，这是精子到达、结合、穿透和融合卵母细胞所必需的过程。因此蛋白磷酸化是获能的一个非常重要的过程，尤其是在酪氨酸残基处的磷酸化是获能过程中发生的最重要的事件之一，且酪氨酸磷酸化可能是细胞中信号转导途径的主要甚至是唯一的指标。作者主要针对蛋白磷酸化、精子中酪氨酸磷酸化的发现、作用和定位，以及影响获能过程中酪氨酸磷酸化的几个因素进行阐述。

The Role of Tyrosine Phosphorylation in Sperm Capacitation

Capacitation is an important physiological prerequisite before sperm cells undergo acrosome reaction and fertilize oocytes.Capacitation is a more sophisticated phenomenon that occurs in the female reproductive tract,it gives sperm the ability to enhance activity,interact with zona pellucida (ZP),perform acrosome reaction and initiate the fusion with the oocyte plasma membrane,and complete the fertilization process.However,the molecular mechanism of sperm capacitation is very complex,although it is not yet fully defined,but the sperm has many structural and biochemical changes after capacitation,such as protein tyrosine phosphorylation,the cholesterol exodus of the sperm membrane,the production of active oxygen and the hyperpolarization of the sperm membrane.Proteins regulate some important phenomena such as capacitation and acrosome reaction by phosphorylation or dephosphorylation,this is the process that sperm must undergo to reach,bind,penetrate and fuse the oocyte.Therefore,protein phosphorylation is a very important process of capacitation,especially phosphorylation at tyrosine residues,which is one of the most important events in the process of capacitation,and tyrosine phosphorylation may be the main or even the only indicator of signal transduction pathways in cells.This text focuses on protein phosphorylation,the discovery,role and localization of tyrosine phosphorylation in sperm,and several factors affecting tyrosine phosphorylation in the process of capacitation.