MALE GERM CELL-EXPRESSED MOUSE GENE TAZ83 ENCODES A PUTATIVE, CYSTEINE-RICH TRANSMEMBRANE PROTEIN (CYRITESTIN) SHARING HOMOLOGIES WITH SNAKE TOXINS AND SPERM-EGG FUSION PROTEINS

Data obtained by cloning of a mouse cDNA (TAZ83) are presented. Its co rresponding gene is expressed in meiotic and haploid testicular germ c ells. The gene encodes a putative, cysteine-rich transmembrane protein with a deduced molecular weight of 90 kilodaltons and an isoelectric point of 5.4. Cysteine patterns within the predicted amino acid sequen ce of the TAZ83 gene product (cyritestin, cysteine-rich, testicular) a re highly conserved when compared to various snake toxins of the disin tegrin metalloproteinase type. The cysteine pattern conservation betwe en cyritestin and a guinea pig sperm-egg fusion protein suggests that TAZ83 codes for a mouse protein with comparable properties or function .