SEMINALPLASMIN - RECENT EVOLUTION OF ANOTHER MEMBER OF THE NEUROPEPTIDE-Y GENE FAMILY

Seminalplasmin, the major basic protein of bull semen, an important re gulator of calcium transport in bovine sperm and a positive modulator of the zona pellucida-induced acrosome reaction, is shown to be a rece ntly created member of the neuropeptide Y gene family. Sequence analys is of the bovine peptide YY-pancreatic polypeptide gene cluster reveal s an unexpected and extensive homology between seminalplasmin and the neuropeptide Y gene family, at the level of both gene structure and pr imary amino acid and nucleotide sequences, The extremely high degree o f homology to the peptide YY gene, in both coding and especially nonco ding regions, suggests that the seminalplasmin gene has arisen by a ve ry recent gene duplication of the bovine peptide YY gene. Despite the more than 95% nucleotide sequence identity, a few specific mutations i n the seminalplasmin gene have resulted in both the loss of the amino- and carboxyl-terminal cleavage sites characteristic of all other memb ers of the neuropeptide Y family and the acquisition of a function app arently unrelated to the neurotransmitter/endocrine role of peptide YY .