As the essential tissue for sperm maturation and storage, the epididymis secretes a number of tissue-specific proteins to exert its functions.Among these proteins, epididymal lipocalins have been intensively studied because of their epididymis-specific expression pattern and clustered genomic ubahdank ipa organization.In this study, rLcn13, a member of the rat epididymal lipocalin family, is identified and elaborately characterized.The cDNA sequence of rLcn13 consists of 719 nucleotides and encodes a 176 amino-acid protein with a predicted N-terminal signal peptide of 19 amino acids.rLcn13 shares a similar genomic structure and predicted 3D protein structure with other lipocalin family members.
A recombinant rLCN13 mature peptide of 157 amino acids is expressed and purified, which is used to raise a polyclonal antibody against rLCN13 with high specificity and sensitivity.Northern blot, western blot, and immunohistochemistry assays reveal that rLcn13 is an epididymis-specific gene which is expressed predominantly in the initial segment and proximal caput epididymis and influenced by androgen.The rLCN13 protein is modified by N-glycosylation and secreted into the epididymal lumen, and then binds to accel lifetime horse supplement the acrosome region of the sperm.Our data demonstrate that rLcn13 exhibits a specific temporospatial expression pattern and androgen dependence, indicating its potential roles in sperm maturation.