富含半胱氨酸的分泌蛋白(CRISPs)在哺乳动物授精过程中的作用

The role of cysteine-rich secretory proteins( CRISPs)in mammalian fertilization

雌雄配子间的结合与融合是哺乳动物授精成功的关键步骤,哺乳动物富含半胱氨酸的分泌蛋白CRISPs家族是一个进化上高度保守的蛋白家族,参与了精卵结合与融合过程,并在其中扮演了多种角色。目前从雄性小鼠生殖道中分离出4个CRISPs家族成员:附睾的CRISP1、睾丸的CRISP2、分布广泛的CRISP3以及与人CRISP1同源的CRISP4,对CRISPs家族蛋白成员的晶体结构分析揭示出CRISP蛋白含有两个功能域,一个是位于N末端的结构保守的CAP结构域,另一个是位于C末端的CRISP蛋白家族特有的CRISP功能域。CAP功能域中含有CAP基序,CRISP功能域由一个短的铰链区和一个离子通道调节区组成,并通过铰链区与CAP结构域相连接。简要回顾了各种CRISP蛋白的发现和特性鉴别过程,希望能从CRISPs的角度对哺乳动物精卵识别、结合与融合的分子机制有更好的了解。

Gamete binding and fusion are essential to fertilization in mammals. A family of cysteine-rich secretory proteins（ CRISPs）in mammals is a highly conserved protein family in evolution,it is involved in the progresses to play multiple roles in mammalian sperm-egg fusion. To date,four members of this family were isolated mainly from the male mouse reproductive tract,epididymal CRISP1,testicular CRISP2,widespread CRISP3 and CRISP4,and a human CRISP1 ortholog. Crystallographic analysis of a CRISP family member revealed that CRISPs contain two domains,a structurally conserved N-terminal CAP（ cysteine-rich secretory proteins（ CRISPS）,antigen 5（ Ag5）,and pathogenesis-related 1（ Pr-1）） domain containing CAP motifs,and a C-terminal cysteine-rich domain（ CRD） only presenting in CRISPs. The CRD domain is comprised of a short Hinge region and an ICR（ ion channel regulator）region and is connected to the CAP domain by the Hinge region. This article presented a detail review of identification and characterization of CRISPs for better understanding of the molecular mechanisms of mammalian sperm-egg fusion in view of CRISPs.