The species-specific egg receptor for sea urchin sperm adhesion is EBR1,a novel ADAMTS protein

摘要: Species-specific adhesion of sperm to the egg during sea urchin fertilization involves interaction adhesive protein,bindin,and a complementary receptor on surface,and serves restrict gene pool individuals same species. We used PCR representation difference analysis clone species-specific for bindin,EBR1,from Strongylocentrotus franciscanus (Sf) and S. purpuratus (Sp). Sf-EBR1 contains novel ADAMTS-like N-terminal domain followed by ∼19 tandem EBR repeats consisting alternating CUB thrombospondin type 1 (TSP-1) domains where last 10 are highly conserved. Recombinant protein corresponding repeat displays bindin-binding activity. The SpEBR1 ortholog has ADAMTS (a disintegrin metalloprotease with type-1 modules) core region eight one-half bindin (EBR) that share 88% identity repeats,but an entirely different hyalin-like (HYR) repeats. Thus,the (EBR1) from both species function as surface mediate adhesion.