SPAG11/isoform HE2C, an atypical anionic beta-defensin-like peptide.

A human caput epididymidal cDNA, HE2C, was cloned based on its homology to the known chimpanzee counterpart, suggesting that the encoded beta-defensin-like peptide represented a conserved component of the innate epididymidal epithelial defense system in primates. An approximately 6kDa HE2- related peptide was co-purified together with other HE2 isoforms from human seminal plasma by affinity chromatography. By its antibody reactivity as shown by Western blot analysis, this peptide was distinct from the more abundant HE2 isoforms and was concluded to correspond to HE2C.

A putative 12-transmembrane domain cotransporter associated with apical membranes of the epididymal duct.

The epithelial cells lining the epididymal duct play an important role in establishing and maintaining the luminal fluid microenvironment. A cDNA, canine epididymal cDNA 11 (CE11), was cloned from the dog epididymis predicting a transport protein involved in this process. The full-length sequence encoded a 12-transmembrane domain protein of 481 amino acids; a splice variant predicted a shorter isoform.

HE6, a two-subunit heptahelical receptor associated with apical membranes of efferent and epididymal duct epithelia.

Human Epididymis-specific protein 6 [HE6 (GPR64)] is a highly conserved, tissue-specific seven-transmembrane receptor of the human epididymis. The rodent counterparts were cloned and 5'-inverse PCR employed to confirm that the cDNA sequences were full length. Downstream from the highly conserved signal peptide-coding sequence, the 5'-regions contained at least six mini-exons of less than 50 nucleotides.

Novel antimicrobial peptide of human epididymal duct origin.

HE2, a gene expressed specifically in human epididymis, gives rise to multiple mRNAs that encode a group of small cationic secretory peptides. Localization of HE2 within the defensin gene cluster and prediction that beta-defensin-like modules exist suggest that these peptides have antimicrobial activity and represent components of the innate epithelial defense system of the epididymal duct. Reverse transcription-polymerase chain reaction analysis confirmed the occurrence of eight human HE2-derived transcripts, including minor mRNA variants, that had previously been shown only in animal species.

Synthesis and glycosylation of CD52, the major 'maturation-associated' antigen of rat spermatozoa, in the cauda epididymidis.

A western and lectin blot analysis was performed of the major 'maturation-associated' antigen of rat spermatozoa, which is the rat counterpart of human CD52. In the absence of a suitable antibody, direct study of this approximately 26 kDa antigen, named previously SMemG, had been difficult. In the present study, these problems were overcome by raising a polyclonal antibody against a chemosynthetic peptide predicted from the cDNA sequence of the antigen.

Novel sperm-binding proteins of epididymal origin contain four fibronectin type II-modules.

Novel fibronectin type II (Fn2)-module proteins were cloned from human and canine epididymal cDNA libraries. cDNA sequences predicted a highly conserved protein family, related but not homologous to ungulate seminal plasma proteins (approximately 50% sequence identity), and the first known examples of proteins with four tandemly arranged Fn2-domains. By Northern blot and in situ hybridization analyses the encoding mRNAs were shown to be abundant products of the epididymal duct epithelium, but not detectable in other tissues.

CD52 mRNA is modulated by androgens and temperature in epididymal cell cultures.

Cultured rat epididymal tissue explants formed >90% pure, adherent growing epithelial cell monolayers. Despite their flattened and apparently androgen receptor-negative phenotype, these cells for a short period kept characteristics of the epididymal duct epithelium, i.e.