Lee Ying-Chu, Liao Chi-, Li Pei-Tzn, Tzeng Woan-Fang, Chu Sin-Tak
Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
Mol Biol Rep. 2003 Sep;30(3):165-72. doi: 10.1023/a:1024985024661.
The 24p3 protein is a 25 kDa glycoprotein that is secreted into the uterine fluid during the proestrous phase of mice. We assessed the effects on spermatozoa motility and on the functions of mouse spermatozoa using the computer-assisted sperm analysis method, cytochemical staining and detection of the protein tyrosine phosphorylation pattern. Compared with the control cells, sperm motility was stimulated by the addition of 24p3 protein into the medium. Introducing 24p3 protein enhanced progressive motility but did not promote the appearance of hyperactivated movement. The presence of 24p3 protein in the medium did not allow the cells to undergo the capacitated protein tyrosine phosphorylation pattern and acrosome reaction. The tyrosine phosphorylation pattern shows phosphoproteins in the range of Mr 50,000-106,000 correlated with the sperm progressive motility after the addition of 24p3 protein into the medium. Using flow cytometry, we assessed the changes in the intracellular pH and measured the intracellular cAMP concentration with an immunodetection kit. The results indicated that the elevation in intracellular pH from 6.67 to 6.89, increase of intracellular cAMP accumulation, and protein tyrosine phosphorylation might be the factors in enhancement of sperm motility as the 24p3 protein bound to the spermatozoa. The 24p3 protein may have a role in regulating flagellar motility.
24p3蛋白是一种25 kDa的糖蛋白，在小鼠动情前期分泌到子宫液中。我们使用计算机辅助精子分析方法、细胞化学染色以及蛋白质酪氨酸磷酸化模式检测，评估了其对精子活力和小鼠精子功能的影响。与对照细胞相比，向培养基中添加24p3蛋白可刺激精子活力。引入24p3蛋白可增强渐进性运动，但不会促进超活化运动的出现。培养基中存在24p3蛋白不会使细胞经历获能的蛋白质酪氨酸磷酸化模式和顶体反应。酪氨酸磷酸化模式显示，在向培养基中添加24p3蛋白后，Mr 50,000 - 106,000范围内的磷蛋白与精子渐进性运动相关。我们使用流式细胞术评估细胞内pH值的变化，并使用免疫检测试剂盒测量细胞内cAMP浓度。结果表明，当24p3蛋白与精子结合时，细胞内pH值从6.67升高到6.89、细胞内cAMP积累增加以及蛋白质酪氨酸磷酸化可能是增强精子活力的因素。24p3蛋白可能在调节鞭毛运动中发挥作用。
