A mouse sperm decapacitation factor receptor is phosphatidylethanolamine-binding protein 1
A mouse sperm decapacitation factor receptor is phosphatidylethanolamine-binding protein 1
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DOI：
10.1530/rep.1.00792
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发表时间：
2005-10-01
期刊：
影响因子：
3.8
通讯作者：
Fraser, LR
中科院分区：
文献类型：
--
作者：
Gibbons, R;Adeoya-Osiguwa, SA;Fraser, LR
获能是哺乳动物精子的关键事件，涉及被称为断能因子（DF）的表面蛋白的损失以及随后获得受精能力。早期研究表明，小鼠精子 DF 与受体 DF-R 结合，该受体与精子质膜的附着似乎涉及糖基磷脂酰肌醇 (GP1) 锚定。在本研究中，DF-R 的纯化和后续测序已鉴定出这种与 23 kDa 相似的蛋白质为磷脂酰乙醇胺结合蛋白 1 (PEBP 1)。为了获得支持序列同源性数据的功能证据，对纯化的重组 PEBP 1 和 PEBP 2 的生物活性进行了评估。虽然 PEBP 1 在浓度高于 1 nmol/l 时能够去除溶液中的 DF 活性，但 PEBP 2 即使在 600 nmol/l 时也无效；这证实了 DF-R 是 PEBP 1。抗 PEBP 1 抗血清可识别重组 PEBP 1 以及小鼠和人类精子裂解物中类似于 23 kDa 的蛋白质。免疫定位研究表明，DF-R/PEBP 1 位于小鼠和人类精子的顶体帽、顶体后区域和鞭毛上，表位可及性依赖于获能状态且是可逆的。用能够裂解GPl锚的磷脂酶处理细胞基本上消除了免疫染色，从而证实了DF-R/PEBP 1的细胞外位置。我们认为DF-R/PEBP 1通过引起头部和鞭毛中精子质膜的改变而在获能中发挥其基本作用，并对膜相关蛋白产生功能影响。获得有关 DF DF-R 相互作用的更多细节可能会在生育治疗和新的避孕方法中产生有用的应用。
Capacitation is a pivotal event for mammalian spermatozoa, involving the loss of surface proteins known as decapacitation factors (DF) and consequent acquisition of fertilizing ability. Earlier studies showed that a mouse sperm DF binds to a receptor, DF-R, whose attachment to the sperm plasma membrane appears to involve a glycosylphosphatidylinositol (GPl) anchor. In the present study, purification and subsequent sequencing of DF-R has identified this similar to 23 kDa protein as phosphatidylethanolamine-binding protein 1 (PEBP 1). To obtain functional evidence that supports sequence homology data, purified recombinant PEBP 1 and PEBP 2 were evaluated for biological activity. While PEBP 1 was able to remove DF activity in solution at concentrations above similar to 1 nmol/l, PEBP 2 was ineffective, even at 600 nmol/l; this confirmed that DF-R is PEBP 1. Anti-PEBP 1 antiserum recognized recombinant PEBP 1 and a similar to 23 kDa protein in both mouse and human sperm lysates. Immunolocalization studies revealed that DF-R/PEBP 1 is located on the acrosomal cap, the post-acrosomal region and the flagellum of both mouse and human spermatozoa, with epitope accessibility being capacitation state-dependent and reversible. Treatment of cells with a phospholipase able to cleave GPl anchors essentially abolished immunostaining, thus confirming the extracellular location of DF-R/PEBP 1. We suggest that DF-R/PEBP 1 plays its fundamental role in capacitation by causing alterations in the sperm plasma membrane in both head and flagellum, with functional consequences for membrane-associated proteins. Obtaining more detail about DF DF-R interactions could lead to useful applications in both fertility treatments and new contraceptive approaches.