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 corresponding gene is expressed in meiotic and haploid testicular germ cells. 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 sequence of the TAZ83 gene product ( cyritestin , cysteine-rich, testicular) are highly conserved when compared to various snake toxins of the disintegrin metalloproteinase type. The cysteine pattern conservation between cyritestin and a guinea pig sperm-egg fusion protein suggests that TAZ83 codes for a mouse protein with comparable properties or function.