Remodeling of the plasma membrane in preparation for sperm-egg recognition: roles of acrosomal proteins.
Remodeling of the plasma membrane in preparation for sperm-egg recognition: roles of acrosomal proteins.
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DOI：
10.4103/1008-682x.152817
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发表时间：
2015-07
影响因子：
2.9
通讯作者：
Baker M
中科院分区：
文献类型：
--
作者：
Tanphaichitr N;Kongmanas K;Kruevaisayawan H;Saewu A;Sugeng C;Fernandes J;Souda P;Angel JB;Faull KF;Aitken RJ;Whitelegge J;Hardy D;Berger T;Baker M
精子与卵子的细胞外基质透明带(ZP)的相互作用是雄配子和雌配子结合的第一步。在过去的60年里，人们一直在研究这一过程的分子机制，所获得的结果既有趣又令人困惑。在这篇文章中，我们描述了我们最近的工作，试图解决之前研究中的两个问题。首先，由于不同的研究人员报道了大量的ZP结合蛋白，这些蛋白是如何在精子-ZP相互作用中共同作用的？第二，为什么一些顶体蛋白具有ZP亲和力？它们主要参与精子与ZP的初始结合，或者更确切地说，参与将顶体反应/反应的精子锚定在ZP上？我们的研究表明，从精子头部前质膜中提取的一些ZP结合蛋白和伴侣蛋白以高分子量(HMW)复合体的形式共存，并且这些复合体在获能精子中具有优先与ZP结合的能力。Zonadherin(Zan)是一种具有ZP亲和力的顶体蛋白，是HMW复合体中的一种蛋白质。免疫沉淀表明，Zan与其他顶体蛋白相互作用，前顶体酶/顶体酶和sp32(ACRBP)也存在于HMW复合体中。对精子上Zan和顶体酶原/顶体酶的免疫检测进一步表明，这两种蛋白质在获能过程中都运输到精子头部表面，在那里精子顶体基质仍然完整，因此它们可能参与了精子与ZP结合的初始步骤。
The interaction of sperm with the egg's extracellular matrix, the zona pellucida (ZP) is the first step of the union between male and female gametes. The molecular mechanisms of this process have been studied for the past six decades with the results obtained being both interesting and confusing. In this article, we describe our recent work, which attempts to address two lines of questions from previous studies. First, because there are numerous ZP binding proteins reported by various researchers, how do these proteins act together in sperm–ZP interaction? Second, why do a number of acrosomal proteins have ZP affinity? Are they involved mainly in the initial sperm–ZP binding or rather in anchoring acrosome reacting/reacted spermatozoa to the ZP? Our studies reveal that a number of ZP binding proteins and chaperones, extracted from the anterior sperm head plasma membrane, coexist as high molecular weight (HMW) complexes, and that these complexes in capacitated spermatozoa have preferential ability to bind to the ZP. Zonadhesin (ZAN), known as an acrosomal protein with ZP affinity, is one of these proteins in the HMW complexes. Immunoprecipitation indicates that ZAN interacts with other acrosomal proteins, proacrosin/acrosin and sp32 (ACRBP), also present in the HMW complexes. Immunodetection of ZAN and proacrosin/acrosin on spermatozoa further indicates that both proteins traffic to the sperm head surface during capacitation where the sperm acrosomal matrix is still intact, and therefore they are likely involved in the initial sperm–ZP binding step.