A hyaluronidase activity of the sperm plasma membrane protein PH-20 enables sperm to penetrate the cumulus cell layer surrounding the egg.
A hyaluronidase activity of the sperm plasma membrane protein PH-20 enables sperm to penetrate the cumulus cell layer surrounding the egg.
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DOI：
10.1083/jcb.125.5.1157
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发表时间：
1994-06
期刊：
影响因子：
--
通讯作者：
Primakoff P
中科院分区：
文献类型：
--
作者：
Lin Y;Mahan K;Lathrop WF;Myles DG;Primakoff P
一个典型的哺乳动物卵子被一个外层包围，外层约有3,000个卵丘细胞，包埋在富含透明质酸的细胞外基质中。目前，广泛提出的模型是，精子顶体完整，穿过卵丘细胞层，并结合到卵透明细胞。目前的模型缺乏对精子如何穿透卵丘层的有力解释.我们报告，精子蛋白PH-20具有透明质酸酶活性，并存在于小鼠和人精子的质膜上。用纯化的重组PH-20短暂处理可以释放小鼠卵周围的所有卵丘细胞。顶体完整的小鼠精子与抗PH-20抗体孵育后不能穿过卵丘层，因此不能到达透明层。这些结果表明，PH-20能够使顶体完整的精子穿透卵丘屏障，揭示了卵丘穿透的机制，从而提供了当前模型中缺失的元素。
A typical mammalian egg is surrounded by an outer layer of about 3,000 cumulus cells embedded in an extracellular matrix rich in hyaluronic acid. A current, widely proposed model is that the fertilizing sperm, while it is acrosome intact, passes through the cumulus cell layer and binds to the egg zona pellucida. This current model lacks a well- supported explanation for how sperm penetrate the cumulus layer. We report that the sperm protein PH-20 has a hyaluronidase activity and is present on the plasma membrane of mouse and human sperm. Brief treatment with purified, recombinant PH-20 can release all the cumulus cells surrounding mouse eggs. Acrosome intact mouse sperm incubated with anti-PH-20 antibodies can not pass through the cumulus layer and thus can not reach the zona pellucida. These results, indicating that PH-20 enables acrosome intact sperm to penetrate the cumulus barrier, reveal a mechanism for cumulus penetration, and thus provide the missing element in the current model.