Molecular cloning of a murine homologue of membrane cofactor protein (CD46): preferential expression in testicular germ cells.

摘要: Human membrane cofactor protein (MCP, CD46) has been suggested, although no convincing evidence proposed, to be a fertilization-associated protein, in addition its primary functions as complement regulator and measles virus receptor. We have cloned cDNA encoding the murine homologue of MCP. This showed 45% identity deduced sequence 62% nucleotide with human Its ectodomains were four short consensus repeats serine/threonine-rich domain, it appeared type 1 23-amino acid transmembrane domain cytoplasmic tail. The expressed on Chinese hamster ovary cell transfectants was 47 kDa SDS/PAGE immunoblotting, approximately 6 larger than testis It served for factor I-mediated inactivation C3b homologous system and, lesser extent, system. Strikingly, major message MCP 1.5 kb predominantly testis. not detected mice defective spermatogenesis or immature germ cells (until 23 days old). Thus, may sperm-dominant which is selectively spermatids during germ-cell differentiation.