Sperm chromatin proteomics identifies evolutionarily conserved fertility factors
Sperm chromatin proteomics identifies evolutionarily conserved fertility factors
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DOI：
10.1038/nature05050
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发表时间：
2006-09-07
期刊：
影响因子：
64.8
通讯作者：
Meyer, Barbara J.
中科院分区：
文献类型：
--
作者：
Chu, Diana S.;Liu, Hongbin;Meyer, Barbara J.
男性不育症是一个长期存在的重大医学问题。精子染色质的完整性是男性生育能力和体外受精潜力的临床指标(1)：染色体非整倍体和DNA解聚或损伤与生殖失败有关。识别对精子染色质结构和包装很重要的保守蛋白质可以揭示不育的普遍原因。在这里，我们结合蛋白质组学、细胞学和秀丽线虫的功能分析来鉴定与生育有关的生精染色质相关蛋白。我们的策略采用了多个步骤：从可比的减数分裂细胞类型中纯化染色质，即那些经历精子发生或卵子发生的细胞；通过多维蛋白质鉴定技术(MudPIT)对与染色质共同纯化的因素进行蛋白质组分析；根据丰度对精子蛋白进行优先排序；以及减去共同的蛋白质以消除一般的染色质和减数分裂因素。我们的方法将与生精染色质共纯化的1099个蛋白质减少到132个蛋白质用于功能分析，生精染色质是目前最广泛的目录。通过RNA干扰降低基因功能，结合蛋白质定位研究，揭示了保守的精子发生特异性蛋白质，这些蛋白质对DNA紧凑、染色体分离和生育至关重要。参与其他过程的因素也在精子发生中发挥了意想不到的作用。我们寻找从线虫到哺乳动物保守的生育因子的策略实现了它的目标：在与线虫蛋白相对应的小鼠基因敲除中，37%(7/19)导致男性不育。因此，我们的清单为确定男性不育的原因和男性避孕药的目标提供了重要机会。
Male infertility is a long-standing enigma of significant medical concern. The integrity of sperm chromatin is a clinical indicator of male fertility and in vitro fertilization potential(1): chromosome aneuploidy and DNA decondensation or damage are correlated with reproductive failure. Identifying conserved proteins important for sperm chromatin structure and packaging can reveal universal causes of infertility. Here we combine proteomics, cytology and functional analysis in Caenorhabditis elegans to identify spermatogenic chromatin-associated proteins that are important for fertility. Our strategy employed multiple steps: purification of chromatin from comparable meiotic cell types, namely those undergoing spermatogenesis or oogenesis; proteomic analysis by multidimensional protein identification technology (MudPIT) of factors that co-purify with chromatin; prioritization of sperm proteins based on abundance; and subtraction of common proteins to eliminate general chromatin and meiotic factors. Our approach reduced 1,099 proteins co-purified with spermatogenic chromatin, currently the most extensive catalogue, to 132 proteins for functional analysis. Reduction of gene function through RNA interference coupled with protein localization studies revealed conserved spermatogenesis-specific proteins vital for DNA compaction, chromosome segregation, and fertility. Unexpected roles in spermatogenesis were also detected for factors involved in other processes. Our strategy to find fertility factors conserved from C. elegans to mammals achieved its goal: of mouse gene knockouts corresponding to nematode proteins, 37% (7/19) cause male sterility. Our list therefore provides significant opportunity to identify causes of male infertility and targets for male contraceptives.