EPPIN

This gene encodes an epididymal protease inhibitor, which contains both kunitz-type and WAP-type four-disulfide core (WFDC) protease inhibitor consensus sequences. Most WFDC genes are localized to chromosome 20q12-q13 in two clusters: centromeric and telomeric. This gene is a member of the WFDC gene family and belongs to the telomeric cluster. The protein can inhibit human sperm motility and exhibits antimicrobial activity against E. coli, and polymorphisms in this gene are associated with male infertility. Read-through transcription also exists between this gene and the downstream WFDC6 (WAP four-disulfide core domain 6) gene. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2014]

Epididymal Peptidase Inhibitor

Serine protease inhibitor that plays an essential role in male reproduction and fertility. Modulates the hydrolysis of SEMG1 by KLK3/PSA (a serine protease), provides antimicrobial protection for spermatozoa in the ejaculate coagulum, and binds SEMG1 thereby inhibiting sperm motility.

Defense response to bacterium Source: UniProtKB
Negative regulation of calcium ion import Source: UniProtKB
Negative regulation of flagellated sperm motility Source: UniProtKB
Negative regulation of peptidase activity Source: UniProtKB

Isoform 1: Secreted; Cell surface. Bound to the surface of testicular and on the head and tail of ejaculate spermatozoa.