Epididymal Protein 3A (EDDM3A)

Post-testicular maturation requires exposure of spermatozoa to the microenvironment of the epididymal lumen. Spermatozoa undergo extensive changes in the epididymis, including enzymatic modifications, loss of pre-existing components and addition of new glycoproteins from epididymal secretions. HE3A encodes a deduced 128-amino acid protein with a calculated molecular mass of 14,903 Da. The protein includes a typical N-terminal signal peptide with a putative signal peptidase cleavage site. RNase protection assays showed that both HE3A and HE3B transcripts are expressed in human epididymis.HE3A did not hybridize to epididymal RNA from any nonprimate species, with the exception of boar. In boar, the HE3-related transcript was up-regulated during postnatal development, suggesting direct or indirect regulation by androgen.