RISPs在哺乳动物授精过程中的作用研究进展

Gamete binding and fusion are essential to fertilization in mammals. A family of cysteine-rich secretory proteins (CRISPs) in mammals which is a highly conserved protein family in evolution, is involved in these progresses and appears to play multiple roles in mammalian sperm-egg fusion. To date, four members of this family have been isolated mainly from the male mouse reproductive tract, epididymal CRISP1, testicular CRISP2, widespread CRISP3 and CRISP4, 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 which contains CAP motifs, and a C-terminal cysteine-rich domain (CRD) which is only present 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 presents a detail review of identification and characterization of CRISPs, expecting to a better understanding of the molecular mechanisms of mammalian sperm-egg fusion in view of CRISPs.