Cloning and sequencing of a cell surface protein encoding gene conserved in sea urchin species

We report the nu~leotide sequence of a fragment of DNA derived from a sea urchin genomic clone containing the cell surface Bep4 (butanol-extracted protein 4)-encoding gene. The structural gene is interrupted by four introns and the promoter region contains TATA and CAAT consensus motifs. The transcription start point (tsp) was also determined. Remarkable homologies, between Bep4 and other proteins known to be involved in cell interactions, were observed regarding two poteintial Ca 2+-binding sites and the corresponding DNA consensus sequences. We also report the conservation of the be@ gene and its corresponding Bep4 protein between various sea urchin species by way of Southern and Western blotting.