Structural Heterogeneity and Protein Composition of Exosome-Like Vesicles (Prostasomes) in Human Semen
Structural Heterogeneity and Protein Composition of Exosome-Like Vesicles (Prostasomes) in Human Semen
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DOI：
10.1002/pros.20860
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发表时间：
2009-02-01
期刊：
影响因子：
2.8
通讯作者：
Mobley, James A.
中科院分区：
文献类型：
--
作者：
Poliakov, Anton;Spilman, Michael;Mobley, James A.
背景资料。人类精液中含有被称为前列腺体的小外体样囊泡。前人已报道前列腺体除了调节顶体反应性外，还通过提高精子的存活率和活力在受精过程中发挥重要作用。据报道，前列腺体的大小在50-500 nm之间，并具有多层脂膜；然而，前列腺体的精细形态从未被详细研究过。方法：用冷冻电子显微镜(EM)观察蔗糖梯度纯化的前列腺体。结果首次报道了冷冻电子显微镜下精液前列腺体的详细结构。至少存在三种不同的主要结构类型的囊泡。在结构分析的同时，我们对前列腺体进行了详细的蛋白质组学分析，从而鉴定了440种蛋白质。这几乎是迄今为止为这些独特颗粒识别的蛋白质数量的三倍，之前识别的一些蛋白质在我们的研究中得到了交叉验证。结论：从本文报道的数据来看，我们假设人类精液中外切体样颗粒的结构异质性反映了它们功能的多样性。我们详细的蛋白质组学分析为未来的结构和功能研究提供了候选蛋白质清单。前列腺69：159-167,2009。(C)2008年Wiley-Liss，Inc.
BACKGROUND. Human seminal fluid contains small exosome-like vesicles called prostasomes. Prostasomes have been reported previously to play an important role in the process of fertilization by boosting survivability and motility of spermatozoa, in addition to modulating acrosomal reactivity. Prostasomes have also been reported to present with sizes varying from 50 to 500 nm and to have multilayered lipid membranes; however, the fine morphology of prostasomes has never been studied in detail.METHODS. Sucrose gradient-purified prostasomes were visualized by cryo-electron microscopy (EM). Protein composition was studied by trypsin in-gel digestion and liquid chromatography/mass spectrometry.RESULTS. Here we report for the first time the detailed structure of seminal prostasomes by cryo-EM. There are at least three distinct dominant structural types of vesicles present. In parallel with the structural analysis, we have carried out a detailed proteomic analysis of prostasomes, which led to the identification of 440 proteins. This is nearly triple the number of proteins identified to date for these unique particles and a number of the proteins identified previously were cross-validated in our study.CONCLUSION. From the data reported herein, we hypothesize that the structural heterogeneity of the exosome-like particles in human semen reflects their functional diversity. Our detailed proteomic analysis provided a list of candidate proteins for future structural and functional studies. Prostate 69: 159-167, 2009. (C) 2008 Wiley-Liss, Inc.