Distribution and dynamics of mouse sperm surface galactosyltransferase: implications for mammalian fertilization.
Distribution and dynamics of mouse sperm surface galactosyltransferase: implications for mammalian fertilization.
复制标题
小鼠精子表面半乳糖基转移酶的分布和动态：对哺乳动物受精的影响。
DOI：
10.1021/bi00031a026
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发表时间：
1995
期刊：
影响因子：
2.9
通讯作者：
Wolf,DE
中科院分区：
文献类型：
--
作者：
Cardullo,RA;Wolf,DE
1995年6月2日收到的摘要：有人提出，小鼠精子表面的β-1，4-半乳糖基转移酶在受精过程中起着透明质酸受体的作用。在本文中，我们使用了两个单价的荧光探针特异性半乳糖基转移酶：UDP-半乳糖和罗丹明α-乳白蛋白的三硝基苯基衍生物。我们发现，半乳糖基转移酶最初存在于顶体完整精子的后头部，但逐渐定位于覆盖顶体区域的质膜后，它与抗半乳糖基转移酶多克隆抗体交联。用钙离子载体A23187处理的标记小鼠精子显示，半乳糖基转移酶保留在顶体胞吐后的后头部。然而，如果半乳糖基转移酶首先与抗体交联并重新分配，然后顶体与A23187反应，则所有头部荧光都丢失。此外，虽然抗半乳糖基转移酶抗体诱导表面重新分布，但它本身并不导致顶体反应终点-顶体酶的释放。最后，使用光漂白后的荧光恢复技术，我们发现，在不存在二价抗体的情况下，小鼠精子表面半乳糖基转移酶表现出40-50%的恢复，并且前头部的扩散系数很高（5-8 x 10-9 cm 2/s）大约是后头部的2倍（2-4 x 10-9 cm 2/s）。当半乳糖基转移酶交联并使用二价抗体重新分布到前头部时，移动的分数降低到20-30%，扩散系数没有显著变化。这些数据表明，小鼠精子表面半乳糖基转移酶具有许多重要的特性，其功能所必需的作为受体的透明质酸，但二价交联的小鼠精子表面半乳糖基转移酶是不足以诱导最终的信号转导事件，导致顶体胞吐。
Revised Manuscript Received June 2, 1995® abstract: It has beenproposed that a mouse sperm surface (3-1, 4-galactosyltransferase functions as a receptor for the zona pellucida during fertilization. In this paper we used two monovalent fluorescent probes specific for galactosyltransferase: a trinitrophenylated derivative of UDP-galactose and rhodaminated a-lactalbumin. We found that galactosyltransferase was initially present over the posterior head of acrosome-intact sperm but became progressively localized to the plasma membrane overlying the acrosomal region after it was cross-linked with an anti-galactosyltransferase polyclonal antibody. Labeled mouse sperm that were treated with the calcium ionophore A23187 revealed that galactosyltransferase remained on the posterior head after acrosomal exocytosis. However, if galactosyltransferase was first cross-linked and redistributed with antibody and then acrosome reacted with A23187, all head fluorescence was lost. In addition, although anti-galactosyltransferase antibody induced a surface redistribution, it did not, by itself, lead to the release of acrosin, the endpoint of the acrosome reaction. Finally, using the technique of fluorescence recovery after photobleaching, we found that, in the absence of bivalent antibody, mouse sperm surface galactosyltransferase exhibited 40—50% recovery with a high diffusion coefficient on the anterior head (5—8 x 10-9 cm2/s) approximately 2 times greater than on the posterior head (2—4 x 10-9 cm2/s). When galactosyltransferase was cross-linked and redistributed to the anterior head using the bivalent antibody, the mobile fraction decreased to 20—30% with no significant change in the diffusion coefficient. These data demonstrate that mouse sperm surface galactosyltransferase has many important properties requisite for its function as a receptor for the zona pellucida, but bivalent cross-linking of mouse sperm surface galactosyltransferase is not sufficient to induce the final signal transduction events leading to acrosomal exocytosis.