Variable Charge, Y-Linked (VCY)

VCY is a member of a family of human VCX/Y genes. This gene family has multiple members on both X and Y chromosomes, and all are expressed exclusively in male germ cells. Members of the VCX/Y family share a high degree of sequence identity, with the exception that a 30-bp unit is tandemly repeated in X-linked members but occurs only once in Y-linked members. VCX/Y genes encode small and highly charged proteins of unknown function. This gene encodes a small, positively charged protein. The presence of a putative bipartite nuclear localization signal suggests that this gene encodes a nuclear protein. The predicted BPY1 protein contains 125 amino acids and has a calculated pI of 9.4. Southern blot analysis indicated that a BPY1 homolog exists on the X chromosome; however, these authors did not isolate a cDNA corresponding to the X-linked gene.